scholarly journals Synthesis of Hydrogel Films Based on PVA, PVP, Starch and Keratin Extracted From Chicken Feathers Wastes for the Potential Biomedical Applications

2021 ◽  
Author(s):  
Mohamed Saad Bala Husain ◽  
Basma Yahya Al-Ashwal ◽  
Arun Gupta ◽  
Swati Sharma ◽  
Venugopal Jayarama Reddy ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Research Study ◽  
Zero Order ◽  
Release Kinetic ◽  
Chicken Feathers ◽  
First Order ◽  
Release Studies ◽  
The Fourier Transform ◽  
Release Kinetic Models ◽  
Hydrogel Films

The aim of this research study was to develop hydrogels samples for using in potential biomedical applications. Hydrogels consisting of different volumes of keratin, polyvinyl alcohol (PVA), Polyvinylpyrrolidone (PVP), and starch. The keratin is derived from the chicken was the primary material on the hydrogels due to attractively for the potential wound healing application. The hydrogel samples were made by using the freeze‑thawing method, and they were examined using the Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), porosity amusement, swelling ratio and keratin release kinetic models that analyzed using (zero-order, first-order Higuchi and Korsmeyer-Peppas models). These results were indicated that feather keratin could use with formulated hydrogels suitably for controlled keratin release studies .

scholarly journals A Review of Gum Hydrocolloid Polyelectrolyte Complexes (PEC) for Biomedical Applications: Their Properties and Drug Delivery Studies

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1796
Author(s):  
Jindrayani Nyoo Putro ◽  
Valentino Bervia Lunardi ◽  
Felycia Edi Soetaredjo ◽  
Maria Yuliana ◽  
Shella Permatasari Santoso ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Biomedical Applications ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Order Equation ◽  
Zero Order ◽  
Natural Polymers ◽  
Polyelectrolyte Complexes ◽  
First Order ◽  
Natural Gum

The utilization of natural gum polysaccharides as the vehicle for drug delivery systems and other biomedical applications has increased in recent decades. Their biocompatibility, biodegradability, and price are much cheaper than other materials. It is also renewable and available in massive amounts, which are the main reasons for its use in pharmaceutical applications. Gum can be easily functionalized with other natural polymers to enhance their applications. Various aspects of the utilization of natural gums in the forms of polyelectrolyte complexes (PECs) for drug delivery systems are discussed in this review. The application of different mathematical models were used to represent the drug release mechanisms from PECs; these models include a zero-order equation, first-order equation, Higuchi, simplified Higuchi, Korsmeyer–Peppas, and Peppas–Sahlin.

Kinetics of catalytic reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst

1983 ◽  
Vol 48 (11) ◽  
pp. 3202-3208 ◽  
Author(s):  
Zdeněk Musil ◽  
Vladimír Pour
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxide ◽  
Rate Equation ◽  
Catalytic Reduction ◽  
Zero Order ◽  
Spectroscopic Measurements ◽  
First Order ◽  
Ir Spectroscopic ◽  
Kinetics Of ◽  
Al2o3 Catalyst

The kinetics of the reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst (8.36 mass % CuO) were determined at temperatures between 413 and 473 K. The reaction was found to be first order in NO and zero order in CO. The observed kinetics are consistent with a rate equation derived from a mechanism proposed on the basis of IR spectroscopic measurements.

scholarly journals Development and Evaluation of Fluoxetine Fast Dissolving Films: An Alternative for Noncompliance in Pediatric Patients

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 778
Author(s):  
Emőke-Margit Rédai ◽  
Paula Antonoaea ◽  
Nicoleta Todoran ◽  
Robert Alexandru Vlad ◽  
Magdalena Bîrsan ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Hydroxypropyl Methylcellulose ◽  
Pharmaceutical Formulations ◽  
Release Kinetic ◽  
Disintegration Time ◽  
Casting Technique ◽  
First Order ◽  
Orodispersible Films ◽  
Folding Endurance

The most used pharmaceutical formulations for children are syrups, suppositories, soft chewable capsules, and mini-tablets. Administrating them might create an administration discomfort. This study aimed to develop and evaluate orodispersible films (ODFs) for pediatric patients in which the fluoxetine (FX) is formulated in the polymeric matrix. Six FX fast dissolving films (10 mg FX/ODF), FX1, FX2, FX3, FX4, FX5, and FX6, were prepared by solvent casting technique. In the composition of the ODFs, the concentration of the hydroxypropyl methylcellulose and the concentration of the propylene glycol were varied. Each formulation of fluoxetine ODF was evaluated by determining the tensile strength, folding endurance, disintegration, behavior in the controlled humidity and temperature conditions, and adhesiveness. All the obtained results were compared with the results obtained for six ODFs prepared without FX. The disintegration time of the FX ODFs was of maximum 88 s for FX2. Via the in vitro releasing study of the FX from the ODFs it was noticed that FX1 and FX2 allow a better release of the drug 99.98 ± 3.81% and 97.67 ± 3.85% being released within 15 min. From the obtained results it was also confirmed that FX ODFs were found to follow first-order release kinetic.

Area-based speciation kinetic analysis of the multipollutant removal in Constructed Wetlands to enhance its treatment efficiency

2021 ◽  
Author(s):  
Manoj Kumar ◽  
Rajesh Singh
Keyword(s):  
Wastewater Treatment ◽  
Kinetic Analysis ◽  
Constructed Wetlands ◽  
Municipal Wastewater ◽  
Zero Order ◽  
Pollutant Removal ◽  
Municipal Wastewater Treatment ◽  
Treatment Efficiency ◽  
First Order ◽  
Present Study Area

In the present study area-based, pollutant removal kinetic analysis was considered using the Zero-order, first-order decay and efficiency loss (EL) models in the constructed wetlands (CWs) for municipal wastewater treatment....

Supercritical Fluid Deposition of Ruthenium Thin Films: A Kinetic Study

2007 ◽  
Vol 992 ◽  
Author(s):  
Christos F. Karanikas ◽  
James J. Watkins
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Deposition Temperature ◽  
Zero Order ◽  
Measurable Effect ◽  
Deposition Rates ◽  
Reaction Pressure ◽  
Deposition Kinetics ◽  
First Order ◽  
Kinetics Of

AbstractThe kinetics of the deposition of ruthenium thin films from the hydrogen assisted reduction of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)(1,5-cyclooctadiene)ruthenium(II), [Ru(tmhd)2cod], in supercritical carbon dioxide was studied in order to develop a rate expression for the growth rate as well as to determine a mechanism for the process. The deposition temperature was varied from 240°C to 280°C and the apparent activation energy was 45.3 kJ/mol. Deposition rates up to 30 nm/min were attained. The deposition rate dependence on precursor concentrations between 0 and 0.2 wt. % was studied at 260°C with excess hydrogen and revealed first order deposition kinetics with respect to precursor at concentrations lower then 0.06 wt. % and zero order dependence at concentrations above 0.06 wt. %. The effect of reaction pressure on the growth rate was studied at a constant reaction temperature of 260°C and pressures between 159 bar to 200 bar and found to have no measurable effect on the growth rate.

A Stable Mixed Element Method for the Biharmonic Equation with First-Order Function Spaces

2017 ◽  
Vol 17 (4) ◽  
pp. 601-616 ◽  
Author(s):  
Zheng Li ◽  
Shuo Zhang
Keyword(s):  
Biharmonic Equation ◽  
Two Dimensions ◽  
Zero Order ◽  
Helmholtz Decomposition ◽  
Numerical Verification ◽  
Order Function ◽  
First Order ◽  
Mixed Element ◽  
New Formulation ◽  
Element Method

AbstractThis paper studies the mixed element method for the boundary value problem of the biharmonic equation {\Delta^{2}u=f} in two dimensions. We start from a {u\sim\nabla u\sim\nabla^{2}u\sim\operatorname{div}\nabla^{2}u} formulation that is discussed in [4] and construct its stability on {H^{1}_{0}(\Omega)\times\tilde{H}^{1}_{0}(\Omega)\times\bar{L}_{\mathrm{sym}}^% {2}(\Omega)\times H^{-1}(\operatorname{div},\Omega)}. Then we utilise the Helmholtz decomposition of {H^{-1}(\operatorname{div},\Omega)} and construct a new formulation stable on first-order and zero-order Sobolev spaces. Finite element discretisations are then given with respect to the new formulation, and both theoretical analysis and numerical verification are given.

scholarly journals Kinetika Slow Release Pupuk Urea Berlapis Chitosan Termodifikasi

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
YC Danarto ◽  
Anggita Nugrahey ◽  
Sela Murni Noviani
Keyword(s):  
Water Retention ◽  
Slow Release ◽  
Zero Order ◽  
Release Profile ◽  
Nitrogen Release ◽  
Diffusion Kinetic ◽  
Urea Fertilizer ◽  
First Order ◽  
Modified Chitosan ◽  
Urea Content

<p>During this time, the use of urea is not efficient, because about 40-70% of nitrogen in the fertilizer is not absorbed by plants. In order to increase the effectivity of nitrogen release in urea fertilizer, it needs to be coated with modified chitosan as slow releasing agent to form a hydrogel material by forming a cross linking with glutaraldehyde cross-linker.The aims of this research is to study the mechanism and the appropriate kinetic model of nitrogen release in slow releasing fertilizer of modified chitosan. This research was conducted by analyzing the ability of bio-hydrogel by calculating the percentage of swelling ratio and water retention of hydrogel and the nitrogen release in slow releasing fertilizer both in the soil and water. The experiments were conducted by varying the amount of urea used which  30 gram, 40 gram, 50 gram, 60 gram and 70 gram of urea fertilizer. The The release profile is then plotted on several models of diffusion kinetic such as zero order, first order, higuchi and korsmeyer peppas. The appropriate model of diffusion kinetic is chosen by the largest correction factor (R2).The results showed that nitrogen release of the slow releasing fertilizer in the soil with 50% urea content  and  the  water  followed  korsmeyer  peppas  model  with  fickian  mechanism. Nitrogen release in the soil with urea content of 30%, 40%, 60%, and 70% followed the korsmeyer peppas model with nonfickian mechanism.</p>

scholarly journals Akinetic model for the consumption of stabilizer in single base gun propellants

2002 ◽  
Vol 67 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Ljiljana Jelisavac ◽  
Milos Filipovic
Keyword(s):  
Life Time ◽  
Order Reaction ◽  
Zero Order ◽  
Final Phase ◽  
Single Base ◽  
First Order ◽  
Low Concentrations ◽  
Zero Order Reaction ◽  
High Concentrations ◽  
Gun Propellants

A suitable kinetic model for the consumption of stabilizer (diphenylamine) in single base gun propellants was investigated and successfully verified. The model assumes that a reaction of shifting order can be applied for the consumption of diphenylamine in single base gun propellants. It was found that the experimental data were well evaluated by a first-order reaction at high concentrations of diphenylamine in the propellant, but by a zero-order reaction at low concentrations during the final phase of the propellant life time. The mechanism of diphenylamine depletion was discussed with relation to the model and the ageing behavior of the propellants. The kinetic parameters of this model, which permit the calculation of the time up to complete consumption of the diphenylamine, were determined. The results were compared with the kinetic data obtained by a widely accepted model, which combines formally reactions of first and zero order, designated as an "exponential and linear" model. All comparisons gave satisfactory agreement.

Simplified estimation of forage degradability in the rumen assuming zero-order degradation kinetics

2008 ◽  
Vol 147 (3) ◽  
pp. 225-240 ◽  
Author(s):  
M. S. DHANOA ◽  
S. LÓPEZ ◽  
R. SANDERSON ◽  
J. FRANCE
Keyword(s):  
Reference Values ◽  
Incubation Time ◽  
Lag Time ◽  
Zero Order ◽  
Regression Equations ◽  
Order Model ◽  
First Order ◽  
Simplified Procedure ◽  
The Impact ◽  
Time Point

SUMMARYIn the present paper, a simplified procedure using few in situ data points is derived and then evaluated (using a large database) against reference values estimated with the standard nylon bag first-order kinetics model. The procedure proposed involved a two-stage mathematical process, with a statistical prediction of some degradation parameters (such as lag time) and then a kinetic model derived by assuming degradation follows zero-order kinetics to determine effective degradability in the rumen (E). In addition to the estimation of washout fraction and discrete lag, which is common to both procedures, the simplified procedure requires measurement of dry matter losses at one incubation time point only. Thus, interference of the animal rumen will be much reduced, which will lead to increased capacity for feed evaluation. Calibration of the zero-order model against the first-order model showed that suitable estimates of E can be obtained with disappearance at 24, 48 or 72 h as the single incubation end time point. The strength of the calibration is such that an end incubation time point as low as 24 h may be sufficient, which may reduce substantially the total incubation time required and thus the impact on the experimental animal. Relevant regression equations to predict reference values of parameters such as lag time or E are also developed and validated.

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