scholarly journals Experimental Studies and Modeling of the Degradation Process of Poly(Lactic-co-Glycolic Acid) Microspheres for Sustained Protein Release

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2042
Author(s):  
Paolo Antonio Netti ◽  
Marco Biondi ◽  
Mariaenrica Frigione
Keyword(s):  
Mathematical Model ◽  
Glycolic Acid ◽  
Experimental Studies ◽  
Double Emulsion ◽  
Degradation Process ◽  
Protein Release ◽  
Chemical Balance ◽  
Sustained Protein Release ◽  
First Time ◽  
Kinetics Of

In this study, poly(lactic-co-glycolic acid) microspheres (PLGA MS)for controlled protein release by double emulsion-solvent evaporation were produced and characterized for their morphological and technological features. MS autocatalytic degradation was described by a mathematical model based on a Michaelis and Menten-like chemical balance. Here, for the first time MS degradation was correlated to the advancement of MS degradation front with respect to the degraded radius, derived from mass loss experiments. The model can satisfactorily describe the kinetics of advancement of the degradation front experimentally derived for all MS formulations, especially when produced at higher PLGA concentrations.

Expansion of Cementitious Materials Exposed to Sulfate Solutions

1993 ◽  
Vol 333 ◽  
Author(s):  
James M. Pommersheim ◽  
James R. Clifton
Keyword(s):  
Experimental Studies ◽  
Degradation Process ◽  
The United States ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Expansion Process ◽  
Second Stage ◽  
Diffusion Controlled ◽  
Kinetics Of ◽  
Low Level Radioactive Waste

ABSTRACTDisposal of low-level radioactive waste in concrete vaults buried underground is being considered in the United States and a potentially significant degradation process is sulfate attack. The results of experimental studies and of modeling of the kinetics of sulfate attack of cement-based materials are given. It was concluded that the expansion process involves a two-stage mechanism. The first stage is likely to be diffusion controlled and the second stage appears to be acceleratory due to the development and spread of cracks.

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

Zeolites Fit For A Crown: Probing Host-Guest Interactions with Thermogravimetric Methods

2018 ◽  
Author(s):  
Asel Sartbaeva ◽  
Paul R. Raithby ◽  
Remi Castaing ◽  
Antony Nearchou
Keyword(s):  
Mass Spectrometry ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Petrochemical Industry ◽  
Rational Use ◽  
New Methodologies ◽  
First Time ◽  
Kinetics Of

Through a combination of thermogravimetry, mass spectrometry and differential thermal analysis, we demonstrate for the first time that all four zeolites show experimental differences in their host-guest interactions with 18C6. In addition, we have estimated the kinetics of 18C6 decomposition, which is a technique that has not been applied to zeolites previously. Using these findings as a toolkit, a more rational use of OSDAs can be utilised to prepare designer zeolites. Furthermore, the new methodologies presented herein can be applied to current zeolites, such as MFI-type zeolites used in the petrochemical industry.

scholarly journals Rapid systemic surge of IL-33 after severe human trauma: a prospective observational study

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Olav Sundnes ◽  
William Ottestad ◽  
Camilla Schjalm ◽  
Peter Lundbäck ◽  
Lars la Cour Poulsen ◽  
...  
Keyword(s):  
High Resolution ◽  
Prospective Observational Study ◽  
Tissue Injury ◽  
Trauma Patients ◽  
Decoy Receptor ◽  
Interleukin 33 ◽  
Injured Patients ◽  
First Time ◽  
Kinetics Of ◽  
Insight Into

Abstract Background Alarmins are considered proximal mediators of the immune response after tissue injury. Understanding their biology could pave the way for development of new therapeutic targets and biomarkers in human disease, including multiple trauma. In this study we explored high-resolution concentration kinetics of the alarmin interleukin-33 (IL-33) early after human trauma. Methods Plasma samples were serially collected from 136 trauma patients immediately after hospital admission, 2, 4, 6, and 8 h thereafter, and every morning in the ICU. Levels of IL-33 and its decoy receptor sST2 were measured by immunoassays. Results We observed a rapid and transient surge of IL-33 in a subset of critically injured patients. These patients had more widespread tissue injuries and a greater degree of early coagulopathy. IL-33 half-life (t1/2) was 1.4 h (95% CI 1.2–1.6). sST2 displayed a distinctly different pattern with low initial levels but massive increase at later time points. Conclusions We describe for the first time early high-resolution IL-33 concentration kinetics in individual patients after trauma and correlate systemic IL-33 release to clinical data. These findings provide insight into a potentially important axis of danger signaling in humans.

scholarly journals What voiced obstruents symbolically represent in Japanese: evidence from the Pokémon universe

2021 ◽  
Vol 37 (1) ◽  
pp. 3-24
Author(s):  
Shigeto Kawahara ◽  
Gakuji Kumagai
Keyword(s):  
Experimental Studies ◽  
Sound Symbolism ◽  
Visual Images ◽  
General Issue ◽  
First Time

Abstract Kawahara, Noto, and Kumagai (2018b) found that within the corpus of existing Pokémon names, the number of voiced obstruents in the characters’ names correlates positively with their weight, height, evolution levels and attack values. While later experimental studies to some extent confirmed the productivity of these sound symbolic relationships (e.g. Kawahara and Kumagai 2019a), they are limited, due to the fact that the visual images presented to the participants primarily differed with regard to evolution levels. The current experiments thus for the first time directly explored how each of these semantic dimensions—weight, height, evolution levels, and attack values—correlates with the number of voiced obstruents in nonce names. The results of two judgment experiments show that all of these parameters indeed correlate positively with the number of voiced obstruents in the names. Overall, the results show that a particular class of sounds—in our case, a set of voiced obstruents—can signal different semantic meanings within a single language, supporting the pluripotentiality of sound symbolism (Winter, Pérez-Sobrino, and Brown 2019). We also address another general issue that has been under-explored in the literature on sound symbolism; namely, its cumulative nature. In both of the experiments, we observe that two voiced obstruents evoke stronger images than one voiced obstruent, instantiating what is known as the counting cumulativity effect (Jäger and Rosenbach 2006).

scholarly journals An Optimized Mathematical Model for Items Supplies Planning of a Logistic System

2016 ◽  
Vol 10 (10) ◽  
pp. 133
Author(s):  
Mohammad Ali Nasiri Khalili ◽  
Mostafa Kafaei Razavi ◽  
Morteza Kafaee Razavi
Keyword(s):  
Mathematical Model ◽  
Mixed Integer ◽  
Logistics System ◽  
Proposed Model ◽  
Multiple Objective Decision Making ◽  
System Requirements ◽  
Purchasing Logistics ◽  
The Cost ◽  
The Mathematical Model ◽  
First Time

Items supplies planning of a logistic system is one of the major issue in operations research. In this article the aim is to determine how much of each item per month from each supplier logistics system requirements must be provided. To do this, a novel multi objective mixed integer programming mathematical model is offered for the first time. Since in logistics system, delivery on time is very important, the first objective is minimization of time in delivery on time costs (including lack and maintenance costs) and the cost of purchasing logistics system. The second objective function is minimization of the transportation supplier costs. Solving the mathematical model shows how to use the Multiple Objective Decision Making (MODM) can provide the ensuring policy and transportation logistics needed items. This model is solved with CPLEX and computational results show the effectiveness of the proposed model.

The kinetics of the decarboxylation of β-resorcylic acid in catechol

1976 ◽  
Vol 29 (2) ◽  
pp. 443 ◽  
Author(s):  
MA Haleem ◽  
MA Hakeem
Keyword(s):  
Rate Equation ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Complex Mechanism ◽  
First Order ◽  
Absolute Reaction Rate ◽  
First Time ◽  
Kinetics Of ◽  
Absolute Reaction ◽  
Reaction Rate Equation

Kinetic data are reported for the decarboxylation of β-resorcylic acid in resorcinol and catechol for the first time. The reaction is first order. The observation supports the view that the decomposition proceeds through an intermediate complex mechanism. The parameters of the absolute reaction rate equation are calculated.

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