Derivation of Kinetic Parameter Dependent Model for the Quantification of the Concentration and Molar Mass of an Enzyme in Aqueous Solution: A Case Study on Aspergillus oryzea α-amylase

2016 ◽  
Vol 10 (3) ◽  
pp. 1-10 ◽  
Author(s):  
Ikechukwu Udema
Polymer ◽  
1980 ◽  
Vol 21 (8) ◽  
pp. 891-894 ◽  
Author(s):  
C ATKINSON ◽  
R DIETZ ◽  
M FRANCIS

Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 612 ◽  
Author(s):  
Marie Emilie Wekre ◽  
Karoline Kåsin ◽  
Jarl Underhaug ◽  
Bjarte Holmelid ◽  
Monica Jordheim

In this case study, we explored quantitative 1H NMR (qNMR), HPLC-DAD, and the Folin-Ciocalteu assay (TPC) as methods of quantifying the total phenolic content of a green macroalga, Ulva intestinalis, after optimized accelerated solvent extraction. Tentative qualitative data was also acquired after multiple steps of purification. The observed polyphenolic profile was complex with low individual concentrations. The qNMR method yielded 5.5% (DW) polyphenols in the crude extract, whereas HPLC-DAD and TPC assay yielded 1.1% (DW) and 0.4% (DW) respectively, using gallic acid as the reference in all methods. Based on the LC-MS observations of extracts and fractions, an average molar mass of 330 g/mol and an average of 4 aromatic hydrogens in each spin system was chosen for optimized qNMR calculations. Compared to the parallel numbers using gallic acid as the standard (170 g/mol, 2 aromatic H), the optimized parameters resulted in a similar qNMR result (5.3%, DW). The different results for the different methods highlight the difficulties with total polyphenolic quantification. All of the methods contain assumptions and uncertainties, and for complex samples with lower concentrations, this will be of special importance. Thus, further optimization of the extraction, identification, and quantification of polyphenols in marine algae must be researched.


2015 ◽  
Vol 789-790 ◽  
pp. 1067-1072
Author(s):  
Ismail Hakki Şahin ◽  
Coşku Kasnakoğlu

In this paper, we address the design of a controller that accomplishes stabilization and reference tracking at various flight conditions by using linear helicopter models. The suggested controller is in the form of an H-infinity gain-scheduler, and is used for stabilization and reference tracking for the 4 axis (heave, pitch, roll and yaw) autopilot. Based on the linear models given for the Puma helicopter, an approximate affine parameter dependent model has been built. Then, a linear parameter dependent controller is synthesized which stabilizes the affine parameter dependent helicopter model. By doing so, a single controller achieves stabilization and reference tracking of a family of linear models by scheduling the controller gains based on the online measurement of the scheduling parameter, which is the forward velocity. Moreover, the affine parameter dependent controller is fitted into the linear models. It is observed that this single parameter dependent controller successfully stabilizes a family of linear helicopter model at different forward flight conditions.


Soft Matter ◽  
2016 ◽  
Vol 12 (9) ◽  
pp. 2542-2549 ◽  
Author(s):  
Thomas Swift ◽  
Linda Swanson ◽  
Mark Geoghegan ◽  
Stephen Rimmer

2016 ◽  
Vol 948 ◽  
pp. 1-18 ◽  
Author(s):  
Carlos Contreras ◽  
Eugene Levin ◽  
Irina Potashnikova

2014 ◽  
Vol 12 (3) ◽  
pp. 307-311 ◽  
Author(s):  
Junfeng Geng ◽  
Brian Johnson ◽  
Andrew Wheatley ◽  
Jack Luo

AbstractUsing a very popular and commonly used surfactant sodium dodecylbenzene sulfonate (SDBS, C18H29SO3Na) for a case study, we report a new method of monitoring different forms of surfactant molecules in aqueous solution and measuring their critical micelle concentration (CMC) by ultraviolet-visible (UV-Vis) spectroscopy. The forms of SDBS micelles are also investigated by synthesizing and characterizing NiB nanoparticles using the micelles as molecular templates. In addition, the observed shifts of UV-Vis bands are analysed from the viewpoint of the electrons locations and distributions within the molecules and the possible overlap of their electronic orbitals between neighbouring molecules in each micelle.


Author(s):  
Stanislav Maiorov ◽  
◽  
Iuliia Lagunova ◽  

Introduction. The article considers the calculation of the strength of a bearing mounted on the connecting rod of a jaw crusher, taking into account all workloads. ISSN 0536-1028 «Известия вузов. Горный журнал», № 3, 2020 117 Object problems. When creating particularly large machines and systems, in the case of their 3D-modeling and detailed study, we are faced with an increased load on the central processor of the computer, as well as on the graphics and RAM modules, which leads to a significant slowdown in the design process and calculations particular. Research aim is to consider the task of selecting a simpler and "easier" for the calculation model programs, not difficult to parameterize, compared with the original bearing model, but providing accuracy in the calculation in an acceptable range of errors. The research also aims to analyze the stress-strain state of the bearing assembly. The main methods. In the calculations, the finite element method was used. Specialized software package APM WinMachine was also used. Computing experiment conducted. Conclusions. The results of a computational experiment satisfy the requirements and can be used to solve further problems of designing bearing assemblies. In the future, a parameter-dependent model can be created to facilitate the calculation using any type of bearing


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