Evaluate the Effect of pH on the Mixed Brine and Chemical Solutions

2016 ◽  
Author(s):  
Cody Chancellor ◽  
Connor Kirby ◽  
Mahmoud Elsharafi
Keyword(s):  
Calcium Ions ◽  
Oil Well ◽  
Superabsorbent Polymer ◽  
Time Intervals ◽  
Ph Values ◽  
Blocking High ◽  
Polymer Volume ◽  
Chemical Solutions ◽  
Ph Range ◽  
Kinetics Of

The purpose of this study is to observe the effects of a superabsorbent polymer (SAP) when it is introduced to brine solutions containing Calcium ions at varying pH values. When injected into an oil well, a superabsorbent polymer will swell, blocking high permeability zones. The swelled polymer will decrease reservoir heterogeneity, diverting injected water to oil rich zones/areas of the formation. Understanding the kinetics of an SAP is crucial to its proper employment. However, when the polymer is introduced to brine solutions containing calcium, reactions involving the ionization of the sodium crosslinker of the polymers result in the destruction of the polymers and the formation of a precipitate. In an attempt to solve this problem, pH values of various concentrations of Calcium Chloride and Sodium Chloride in deionized water solutions will be varied and introduced to polymer samples to determine if lowering the pH can prevent precipitation. The procedure includes first introducing hydrochloric acid to brine mixtures, mixing and agitating the polymer with the brine solution, and lastly recording the results. The measurements to be recorded will include the volume of the polymers before, during, and after the swelling process. From this data, the swelling ratios of the polymer samples will be calculated, graphed, and contrasted appropriately according to time intervals and the pH of each sample. By following this procedure, the data shows that a very low pH can significantly inhibit the extent to which the polymer precipitates out with Calcium ions. Temperature tends to decrease polymer volume in brines with pH values above the 1–2 pH range, while pH values in or below said range increase in volume substantially.

In Vitro Interaction between Venous Blood Clots and Radiopharmaceuticals

1985 ◽  
Vol 24 (04) ◽  
pp. 173-179 ◽  
Author(s):  
B. R. R. Persson ◽  
V. Kempi
Keyword(s):  
Room Temperature ◽  
Venous Blood ◽  
Gel Chromatography ◽  
Time Intervals ◽  
Ph Values ◽  
Blood Clots ◽  
Glass Tubes ◽  
Ph Range ◽  
In Vitro Interaction

SummaryClots of 1 ml venous blood formed in glass tubes after 10 min at room temperature were incubated at 37° C with the radiopharmaceutical to be studied. Methods for quality control of the radiopharmaceuticals were compared. Gel chromatography scanning was found to give reliable information. The incorporation into the clot was studie’d at different pH values and after various time intervals. The highest incorporation was found for 125I-fibrinogen and for 99mTc-mac-roaggregates of albumin, followed by 99mTc-sulphur colloid and 99mTc-strep-tokinase at pH less than 2. The titrated initial dose of 99mTc-streptoki-nase was studied at various pH levels. The lysing effect was less in the pH range 1-2.5, where the best labeling yield was obtained. The inactivation of streptokinase by the labeling procedure was also studied with im-munoelectrophoresis and decomposition of casein. In vitro studies of the interaction of radiopharmaceuticals with clots add information for the clinical use of radiopharmaceuticals for thrombus localization.

The kinetics of the reaction of N,N-dimethyl-2-phenylaziridinium ion with bovine erythrocyte acetylcholinesterase

1970 ◽  
Vol 48 (3) ◽  
pp. 244-250 ◽  
Author(s):  
Jocelyn E. Purdie ◽  
R. M. Heggie
Keyword(s):  
Rate Constant ◽  
Order Rate Constant ◽  
Bovine Erythrocyte ◽  
Acidic Group ◽  
Ph Values ◽  
Order Rate ◽  
Decreasing Ph ◽  
Ph Range ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of the hydrolysis of N,N-dimethyl-2-phenylaziridinium ion (DPA) have been studied over the pH range 5.5–8.0 as have the kinetics of the interaction of DPA with bovine erythrocyte acetyl-cholinesterase. The enzyme is initially inhibited reversibly and subsequently irreversibly towards acetylcholine hydrolysis. The hydrolysis of DPA was found to be pH independent over the range studied while the reversible noncompetitive inhibition increased with increasing pH, the data suggesting the requirement for a basic group on the enzyme with a pKa of about 6.5.Between pH values of 6.0 and 8.0 the kinetics of the irreversible inhibition are consistent with either of two kinetically indistinguishable mechanisms, one involving transformation of the initial reversible complex and the other an independent attack on the uncomplexed enzyme. The first mechanism gives rise to a first-order rate constant which is comparable with that for the hydrolysis of DPA but which increases with decreasing pH; an acidic group on the enzyme with pKa between 6.0 and 7.0 may be involved. The second-order rate constant arising from the second treatment goes through a maximum at pH 7.3. At pH 5.5 the kinetics are not consistent with either mechanism.

scholarly journals Appearance of Platelet-Clumping Substance after Acidification of Plasma

Blood ◽  
1968 ◽  
Vol 31 (3) ◽  
pp. 348-357 ◽  
Author(s):  
HIROH YAMAZAKI ◽  
HIROSHI MURASE ◽  
TATSUO SHIMAMOTO ◽  
TAKIO SHIMAMOTO
Keyword(s):  
Calcium Ions ◽  
Standard Error ◽  
Room Temperature ◽  
Ph Value ◽  
Platelet Rich Plasma ◽  
Final Concentration ◽  
Ringer’S Solution ◽  
Ph Values ◽  
Edta Plasma ◽  
Ph Range

Abstract 1. The pH values of heparinized plasma from ten normal rabbits were from 7.53 to 7.80. The average pH and standard error was 7.69 ± 0.03. These plasmas did not show platelet-clumping activity when exposed to the platelet-saline suspension from the same or other normal rabbits. The platelet-clumping substance was not observed in all ten cases after alkalinization of the plasma to pH values ranging from 8.32 to 9.40. On the contrary, immediately after acidification of the plasmas, the platelet-clumping substance appeared at pH values from 4.90 to 6.82 at room temperature. The range of the lower pH value, in which the platelet-clumping substance was observed, was 4.90-5.60 (5.15 ± 0.07 in average) and the upper range was 5.95-6.82 (6.27 ± 0.12 in average). The pH range at which the strongest clumping of platelets appeared was 5.22-5.95 (5.61 ± 0.07 in average). The platelet-clumping substance did not disappear after the pH of the acidified plasma was reneutralized to the original value. 2. No clumping was found after the addition of citrated, oxalated, EDTA-plasma or serum even when they were acidified. After the pH value of the citrated, oxalated or EDTA-plasma was changed from 4.85 ± 0.39 to 7.55 ± 0.03 and in the presence of calcium ions (10 mM.), platelet-clumping activity was observed. After the addition of citrate (0.38 percent in final concentration), oxalate (0.2 percent in final concentration), or EDTA (0.1 percent in final concentration) to the heparinized plasma the platelet-clumping substance did not disappear. In the case of serum, the platelet-clumping activity did not appear after the pH changes. 3. The platelet-clumping substance in the acidified plasma was heat-labile; it was detected after BaSO4-adsorption and defibrination; it was stable in storage at 4 C., and it was not dialyzable against Ringer’s solution for 72 hours. It induced platelet clumping not only in citrated platelet-rich plasma but also in the platelet-saline suspension. 4. The properties of the platelet-clumping substance in the acidified plasma were compared with that of substances known to have platelet-clumping activity and the experimental evidences showing the differences to ADP, thrombin, ADP-cofactor and thrombocyte agglutinating factors have been detailed.

Kinetic of oxidation of methyl orange by vanadium(V) under conditions VO2+ and decavanadates coexist: Catalysis by Triton X-100 micellar medium

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Methyl Orange ◽  
Solution Ph ◽  
Vanadium Concentration ◽  
Limiting Behavior ◽  
First Order ◽  
First Order Kinetics ◽  
Ph Range ◽  
Kinetic Pattern ◽  
Triton X ◽  
Kinetics Of

The kinetics of oxidation of methyl orange by vanadium(V) {V(V)} has been investigated in the pH range 2.3-3.79. In this pH range V(V) exists both in the form of decavanadates and VO2+. The kinetic results are distinctly different from the results obtained for the same reaction in highly acidic solution (pH < 1) where V(V) exists only in the form of VO2+. The reaction obeys first order kinetics with respect to methyl orange but the rate has very little dependence on total vanadium concentration. The reaction is accelerated by H+ ion but the dependence of rate on [H+] is less than that corresponding to first order dependence. The equilibrium between decavanadates and VO2+ explains the different kinetic pattern observed in this pH range. The reaction is markedly accelerated by Triton X-100 micelles. The rate-[surfactant] profile shows a limiting behavior indicative of a unimolecular pathway in the micellar pseudophase.

The Malachite Green Biodegradation in Bioreactors on Various pH Domains

2019 ◽  
Vol 70 (8) ◽  
pp. 2996-2999
Author(s):  
Viorel Gheorghe ◽  
Catalina Gabriela Gheorghe ◽  
Andreea Bondarev ◽  
Vasile Matei ◽  
Mihaela Bombos
Keyword(s):  
Malachite Green ◽  
Contact Time ◽  
Dominant Species ◽  
Wastewater Treatment Plants ◽  
Organic Substances ◽  
Biological Degradation ◽  
Growth Promoters ◽  
Ph Values ◽  
Biological Sludge ◽  
Ph Range

In the experimental study was studied the malachite green colorant biodegradation in biological sludge with biological activity. The biodegradability tests were carried out in laboratory bioreactors, on aqueous solutions of green malachite contacted with microorganisms in which the dominant species is Paramecium caudatum, in a pH range between 8 and 12, temperatures in the ranges 25-350C, using pH neutralizing substances and biomass growth promoters. The colorant initial concentrations and those obtained after biological degradation depending on the contact time, at certain pH values, were established through UV-Vis spectrometry. The studies have shown the measure of possible biological degradation of some organic substances with extended uses, with largely aromatic structure, resistance to biodegradation of microorganisms, commonly used in wastewater treatment plants.

scholarly journals Single entity electrochemistry and the electron transfer kinetics of hydrazine oxidation

Nano Research ◽  
2021 ◽  
Author(s):  
Ruiyang Miao ◽  
Lidong Shao ◽  
Richard G. Compton
Keyword(s):  
Electron Transfer ◽  
Bulk Solution ◽  
Relative Contribution ◽  
Rate Determining Step ◽  
Multistep Process ◽  
Ph Range ◽  
Electro Catalytic Oxidation ◽  
Single Particle Impact ◽  
The Impact ◽  
Kinetics Of

AbstractThe mechanism and kinetics of the electro-catalytic oxidation of hydrazine by graphene oxide platelets randomly decorated with palladium nanoparticles are deduced using single particle impact electrochemical measurements in buffered aqueous solutions across the pH range 2–11. Both hydrazine, N2H4, and protonated hydrazine N2H5+ are shown to be electroactive following Butler-Volmer kinetics, of which the relative contribution is strongly pH-dependent. The negligible interconversion between N2H4 and N2H5+ due to the sufficiently short timescale of the impact voltammetry, allows the analysis of the two electron transfer rates from impact signals thus reflecting the composition of the bulk solution at the pH in question. In this way the rate determining step in the oxidation of each specie is deduced to be a one electron step in which no protons are released and so likely corresponds to the initial formation of a very short-lived radical cation either in solution or adsorbed on the platelet. Overall the work establishes a generic method for the elucidation of the rate determining electron transfer in a multistep process free from any complexity imposed by preceding or following chemical reactions which occur on the timescale of conventional voltammetry.

Derivatives of isatin in aqueous solution. I. Kinetics of ring opening of Isatin-5-sulfonate

1981 ◽  
Vol 34 (2) ◽  
pp. 365 ◽  
Author(s):  
H Stunzi
Keyword(s):  
Ring Opening ◽  
Rate Of Change ◽  
Spectroscopic Methods ◽  
Ph Values ◽  
Buffer Region ◽  
Pka Value ◽  
Back Titration ◽  
Kinetics Of ◽  
Derivatives Of ◽  
Sulfonate Anion

The reactions of isatin-5-sulfonate anion (si-) which cause a hysteresis in pH titrations were studied by pH-metric and n.m.r, spectroscopic methods. Rapid alkalimetric titrations [I 0.15 M (KNO3),37�] gave the pKa value corresponding to the addition of OH- to si- [pKa(ring) 9.55]. The slow ring opening to the sulfonatoisatate dianion (sia2-) led to a drift of the pH values towards an equilibrium buffer region. Its pKa, value [pKa(eq) 3.44] corresponds to the reaction si-+H2O ↔ sia 2-+H+ Rapid back-titration gave the pKa value of the ring-opened species Hsia- [pKa(open) c. 1.3]. The rate law for the ring opening d[sia]/dt=k2 [siOH](OH)+k1*[si] was obtained from the rate of change of pH. N-Methylisatin-5-sulfonate behaves analogously.

Kinetics of bioactive compounds in functional spice Jiangpo during thermal processing

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Xiaoyan Dai ◽  
Chenhuan Yu ◽  
Qiaofeng Wu
Keyword(s):  
Kinetic Parameters ◽  
Bioactive Compounds ◽  
Thermal Processing ◽  
Order Rate Constant ◽  
Heat Processing ◽  
Order Kinetic ◽  
Time Intervals ◽  
First Order ◽  
Order Kinetic Model ◽  
Kinetics Of

Abstract Jiangpo is an increasingly popular East Asian spice which is made from Mangnolia officinalis bark and ginger juice. Since it induces bioactive compounds decomposition and has influence on final flavor and fragrance, cooking is regarded as the key operation in preparation of Jiangpo. To evaluate the bioactive compounds content changes of Jiangpo during thermal processing, kinetic parameters including reaction order, rate constant, T1/2 and activation energy of bioactive markers namely honokiol, magnolol and curcumin were determined. Cooking was set at temperatures 60, 90 and 120 °C for selected time intervals. Results displayed the thermal kinetic characteristics of the three compounds. Thermal degradation of Honokiol and magnolol both followed first order kinetic model and the loss of curcumin fitted second order. A mathematical model based on the obtained kinetic parameters has also been developed to predict the degradation of honokiol, magnolol and curcumin in non-isothermal state. All the information in this paper could contribute necessary information for optimizing the existing heat processing of Jiangpo.

scholarly journals Kinetics of thiamin cleavage by sulphite

1969 ◽  
Vol 113 (4) ◽  
pp. 611-615 ◽  
Author(s):  
J. Leichter ◽  
M. A. Joslyn
Keyword(s):  
Aqueous Solutions ◽  
Rate Constant ◽  
Sulphur Dioxide ◽  
First Order ◽  
Ph Values ◽  
Rate Of Reaction ◽  
Kinetics Of

Results are presented on the rate of thiamin cleavage by sulphite in aqueous solutions as affected by temperature (20–70°), pH(2·5–7·0), and variation of the concentration of either thiamin (1–20μm) or sulphite (10–5000μm as sulphur dioxide). Plots of the logarithm of percentage of residual thiamin against time were found to be linear and cleavage thus was first-order with respect to thiamin. At pH5 the rate was also found to be proportional to the sulphite concentration. In the pH region 2·5–7·0 at 25° the rate constant was 50m−1hr.−1 at pH5·5–6·0, and decreased at higher or lower pH values. The rate of reaction increased between 20° and 70°, indicating a heat of activation of 13·6kcal./mole.

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