Nitrate and chloride formation in chloramination

1994 ◽  
Vol 30 (9) ◽  
pp. 101-110
Author(s):  
V. Diyamandoglu
Keyword(s):  
Kinetic Model ◽  
Analytical Method ◽  
Kinetic Data ◽  
Experimental Results ◽  
Mass Balances ◽  
Time Profiles ◽  
Slow Decay ◽  
Concentration Time ◽  
End Products ◽  
Chlorine Residuals

The formation of nitrate and chloride as end-products of chloramination (combined chlorination) was investigated at pH ranging between 6.9 and 9.6 at 25°C. The experimental results comprised concentration-time profiles of combined chlorine residuals along with nitrate and chloride. Nitrite, if present, was always below the detectibility limit of the analytical method used (25 ppb). Mass balances on chlorine species depicted that chloride formed during the slow decay of combined chlorine residuals does not account for all the chlorine lost. This substantiates the formation of other reaction end-products which are yet to be identified. A kinetic model for chloramination is proposed based on the kinetic data obtained in this study.

scholarly journals Physiologically Based Pharmacokinetic Models of Probenecid and Furosemide to Predict Transporter Mediated Drug-Drug Interactions

2020 ◽  
Vol 37 (12) ◽  
Author(s):  
Hannah Britz ◽  
Nina Hanke ◽  
Mitchell E. Taub ◽  
Ting Wang ◽  
Bhagwat Prasad ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Organic Anion ◽  
Plasma Concentrations ◽  
Whole Body ◽  
Time Profiles ◽  
Pbpk Models ◽  
Physiologically Based Pharmacokinetic ◽  
Concentration Time ◽  
Anion Transporter ◽  
Physiologically Based

Abstract Purpose To provide whole-body physiologically based pharmacokinetic (PBPK) models of the potent clinical organic anion transporter (OAT) inhibitor probenecid and the clinical OAT victim drug furosemide for their application in transporter-based drug-drug interaction (DDI) modeling. Methods PBPK models of probenecid and furosemide were developed in PK-Sim®. Drug-dependent parameters and plasma concentration-time profiles following intravenous and oral probenecid and furosemide administration were gathered from literature and used for model development. For model evaluation, plasma concentration-time profiles, areas under the plasma concentration–time curve (AUC) and peak plasma concentrations (Cmax) were predicted and compared to observed data. In addition, the models were applied to predict the outcome of clinical DDI studies. Results The developed models accurately describe the reported plasma concentrations of 27 clinical probenecid studies and of 42 studies using furosemide. Furthermore, application of these models to predict the probenecid-furosemide and probenecid-rifampicin DDIs demonstrates their good performance, with 6/7 of the predicted DDI AUC ratios and 4/5 of the predicted DDI Cmax ratios within 1.25-fold of the observed values, and all predicted DDI AUC and Cmax ratios within 2.0-fold. Conclusions Whole-body PBPK models of probenecid and furosemide were built and evaluated, providing useful tools to support the investigation of transporter mediated DDIs.

Testing a KrCl excilamp as new enhanced UV source for 4-chlorophenol degradation: Experimental results and kinetic model

2010 ◽  
Vol 49 (1) ◽  
pp. 113-119 ◽  
Author(s):  
M. Gomez ◽  
M.D. Murcia ◽  
J.L. Gomez ◽  
G. Matafonova ◽  
V. Batoev ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Experimental Results

Evaluating the clinical impact of a shortened infusion duration for ramucirumab: A population pharmacokinetic model-based approach.

2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 191-191
Author(s):  
Paolo Abada ◽  
Yiu-Keung Lau ◽  
Ran Wei ◽  
Lisa O’Brien ◽  
Amanda Long ◽  
...  
Keyword(s):  
Infusion Rate ◽  
Population Pharmacokinetic Model ◽  
Pharmacokinetic Model ◽  
Study Data ◽  
Population Pharmacokinetic ◽  
Time Profiles ◽  
Concentration Time ◽  
Increased Risk ◽  
Grade 3 ◽  
Infusion Duration

191 Background: Ramucirumab is a human recombinant immunoglobin G1 monoclonal antibody (mAb) antagonist of vascular endothelial growth factor receptor-2. Ramucirumab dosed at 8 mg/kg every 2 weeks or 10 mg/kg every 3 weeks, either as monotherapy or in combination with chemotherapy, was initially studied with as an intravenous infusion over 60 minutes following premedication with a histamine-1 receptor antagonist. Lengthy intravenous infusions are inconvenient for patients and increase the workloads of nursing and administrative staff. Shortening the infusion duration of ramucirumab could therefore benefit both patients and healthcare professionals. The current analysis determined the impact such a change could have on the pharmacokinetic (PK) profile of ramucirumab. Additionally, the relationship between infusion rate and incidence of immediate infusion-related reactions (IRRs; occurring on the day of administration), common adverse events associated with mAb infusions, was assessed. Methods: A population pharmacokinetic model was established using concentration–time data collected from 2522 patients who received one of five different ramucirumab regimens involving an intravenous infusion over ~60 minutes in 17 clinical studies. The final PK model was used to simulate concentration–time profiles and exposure parameters following ramucirumab infusion durations of 30 vs 60 min. Phase II/III clinical study data from patients receiving ramucirumab were pooled to assess the association between ramucirumab infusion rate and incidence of immediate IRRs using multivariate logistic regression analysis. Results: Ramucirumab infusions of 30- and 60-min durations resulted in equivalent concentration–time profiles and, hence, equivalent systemic exposure to ramucirumab. Among 3216 patients receiving ramucirumab in phase II/III studies, 254 (7.9%) had at least one immediate any-grade IRR; 17 (0.5%) experienced grade ≥3 immediate IRRs. The incidence of immediate IRRs (any grade or grade ≥3) was similar across infusion rate quartiles. Under multivariate logistic analysis, infusion rate was not significantly associated with an increased risk of an immediate IRR (odds ratio per 1 mg/min increase 1.014, 95% confidence interval 0.999, 1.030; p=0.071). Conclusions: Administering ramucirumab using different infusion durations (30 vs 60 min) did not affect ramucirumab exposure. Analysis of clinical study data showed a faster infusion rate was not associated with an increased risk of immediate IRRs. It is considered unlikely that shortening the infusion duration of ramucirumab will impact its clinical efficacy or overall safety profile, and is now an option for administration in the U.S.

On the Impossibility of an OH-Radical Model for Photosynthetic Water Oxidation / Über die Unmöglichkeit eines OH-Radikalmodells für die photosynthetische Wasseroxidation

1972 ◽  
Vol 27 (2) ◽  
pp. 172-176 ◽  
Author(s):  
Gerhard Vierke
Keyword(s):  
Kinetic Model ◽  
Water Oxidation ◽  
Photosynthetic Apparatus ◽  
Experimental Results ◽  
Oh Radicals ◽  
Oh Radical ◽  
Inherent Property ◽  
Evolving System ◽  
Photosynthetic Water Oxidation ◽  
Radical Model

If it is assumed that the oscillating O2 flash yield sequence of algae and chloroplasts predominantly reflects an inherent property of the O2 evolving system of the photosynthetic apparatus it is shown that the OH-radical model (O2 production by recombination of four OH radicals) is contradictory to the experimental results because it predicts an aperiodic O2 flash yield sequence.Several experimental facts already known strongly indicate that the OH-radical model is not consistent with the kinetic model for O2 evolution of KOK et al. either.

A New Kinetic Model for The Nucleation and Growth of Self-Interstitial Clusters in Silicon

2001 ◽  
Vol 669 ◽  
Author(s):  
Christophe J. Ortiz ◽  
Daniel Mathiot
Keyword(s):  
Kinetic Model ◽  
Inverse Modeling ◽  
Nucleation And Growth ◽  
Experimental Results ◽  
Physical Parameters ◽  
Formation Energies ◽  
Good Agreement

ABSTRACTA model for nucleation and growth of {311} defects is proposed on the basis of thermodynamic and kinetic considerations. Simulated results are discussed and compared to experimental results found in the literature. According to our model it is found that formation energies of self-interstitial clusters depends on the local interstitial supersaturation. Physical parameters extracted from experimental results by inverse modeling are in good agreement with recent values published in the literature.

scholarly journals Kill kinetics and regrowth patterns of Pseudomonas aeruginosa exposed to concentration-time profiles of tobramycin simulating in vivo infusion and bolus dosing.

1996 ◽  
Vol 40 (5) ◽  
pp. 1321-1324
Author(s):  
P J Wood ◽  
L L Ioannides-Demos ◽  
E B Bastone ◽  
W J Spicer ◽  
A J McLean
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Peak Concentration ◽  
Bacteriostatic Activity ◽  
Antibiotic Concentration ◽  
Initial Profile ◽  
Time Curve ◽  
Time Profiles ◽  
Concentration Time

Pseudomonas aeruginosa ATCC 27853 was exposed to tobramycin concentration-time profiles modelling in vivo bolus and infusion dosing. Dependence of bactericidal and bacteriostatic activity on the initial profile of peak concentration (bolus effect > infusion) and area under the antibiotic concentration-time curve was observed at peak concentration/MIC ratios of 10 or below.

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