Zinc glutarate-mediated copolymerization of CO2 and PO – parameter studies using design of experiments

2017 ◽  
Vol 7 (13) ◽  
pp. 2897-2905 ◽  
Author(s):  
J. Marbach ◽  
B. Nörnberg ◽  
A. F. Rahlf ◽  
G. A. Luinstra
Keyword(s):  
Design Of Experiments ◽  
Surface Coverage ◽  
P Parameter

Parameter studies of the PO/CO2-copolymerization revealed the importance of the surface coverage of a nanoscopic ZnGA catalyst.

The microstructure of functionalized poLyacrylonitrile beads for bioseparations

1990 ◽  
Vol 48 (4) ◽  
pp. 1094-1095
Author(s):  
Eduardo A. Kamenetzky ◽  
David A. Ley
Keyword(s):  
Aqueous Solution ◽  
Affinity Chromatography ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Surface Coverage ◽  
Vacuum Impregnation ◽  
Thin Sections ◽  
Selective Staining ◽  
Low Viscosity ◽  
Diamond Knife

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.

Further Evidence that Glycoprotein IIb-IIIa Mediates Platelet Spreading on Subendothelium

1991 ◽  
Vol 65 (02) ◽  
pp. 202-205 ◽  
Author(s):  
Harvey J Weiss ◽  
Vincet T Turitto ◽  
Hans R Baumgartner
Keyword(s):  
Platelet Adhesion ◽  
Surface Coverage ◽  
Rabbit Aorta ◽  
Conclusive Evidence ◽  
Initial Contact ◽  
Single Exposure ◽  
Vessel Segment ◽  
Multiple Exposures ◽  
Wall Interaction ◽  
Platelet Spreading

SummaryIn order to explore further the mechanism by which glycoprotein GPIIb-IIIa promotes platelet vessel wall interaction, platelet adhesion to subendothelium was studied in an annular chamber in which subendothelium from rabbit aorta was exposed at a shear rate of 2,600 s−1 to blood from patients with thrombasthenia. Perfusions were conducted for each of 5 exposure times (1 ,2,3, 5 and 10 min), and the percent surface coverage of the vessel segment with platelets in the contact (C) and spread (S) stage was determined. Increased values of platelet contact (C) were obtained in thrombasthenia at all exposure times; this finding is consistent with a defect in platelet spreadirg, based on a previously described kinetic model of platelet attachment to subendothelium. According to this model of attachment, increased values of platelet contact (C) at a single exposure time may be indicative of either a defect in spreading (S) or initial contact (C), but multiple exposures will result in increased contact only for defects which are related to defectiye platelet spreading (s).The results obtained over a broad range of exposure times provide more conclusive evidence that GPIIb-IIIa mediates platelet spreading than those previously obtained at single exposure times.

Automated Microdensitometry And Protein Assays As Measures For Platelet Adhesion And Aggregation On Collagen Coated Slides Under Controlled Flow Conditions

1979 ◽  
Author(s):  
R Muggli ◽  
H Baumgartner ◽  
Th Tschopp
Keyword(s):  
Surface Coverage ◽  
Platelet Surface ◽  
En Face ◽  
Uncoated Surface ◽  
Unit Surface ◽  
Perfusion Time ◽  
Flowing Blood ◽  
Controlled Flow ◽  
Protein Assays ◽  
Microscope Slides

Microscope slides were homogeneously coated over a length of 2 cm with a mixture of soluble and fibrillar collagen and exposed at 37°C and under laminar flow to citrated whole rabbit blood at a flow-rate of 100 ml/min. Surface coverage with platelets (adhesion) and platelet accumulations higher than about 5 μm in height (aggregation) were determined by automated microdensitometry of fuchsine stained ‘en face’ preparations. The platelet mass per unit surface was measured with a modified Lowry technique whose sensitivity was equivalent to 5×l05platelets. Platelet number, amount of protein and surface coverage with platelet accumulations correlated. After a perfusion time of 10 min thrombi up to 30 μm in height and oriented in the direction of flow had developed on the collagen coated area. Surface coverage with platelets was 75% and the amount of deposited protein 1.4 μg/mm2(2×l06platelets/mm2). On the uncoated surface single platelets predominated; the surface coverage was 20% and the density of platelets 8×104/mm2. Acetyl- salicylic acid at 100 μm decreased platelet aggregation by about 80% without affecting adhesion.The new parallel plate perfusion system offers rapid quantitation of platelet-surface and platelet-platelet interaction after exposure to flowing blood and iftay also be diagnostically useful.

Projektowanie dla jakości metodami Shainina i Taguchiego

2008 ◽  
pp. 36-38
Author(s):  
Jarosław Sęp ◽  
Andrzej Pacana
Keyword(s):  
Design Of Experiments

Zespół metod wykorzystywanych do planowania eksperymentów określa się jako Design of Experiments -DOE. Celem stosowania DOE jest uzyskanie jak największej ilości wartościowych i wiarygodnych informacji o badanym wyrobie lub procesie na podstawie jak najmniejszej liczby doświadczeń. W artykule zwrócono uwagę na stosunkowo mało znane metody opracowane przez Shainina oraz Taguchiego. Przedstawiono dobór parametrów metodą Shainina i Taguchiego na przykładzie procesu toczenia.

Defect Reduction in Ring Blank Casting Through Design of Experiments

2015 ◽  
Vol 9 (6) ◽  
pp. 536 ◽  
Author(s):  
P. Kannan ◽  
K. Balasubramanian ◽  
R. Vinayagamoorthy
Keyword(s):  
Design Of Experiments ◽  
Defect Reduction ◽  
Ring Blank

The Nature of Chemisorbed CO2 in Zeolite A

2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski
Keyword(s):  
Solid State ◽  
Ir Spectroscopy ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Surface Coverage ◽  
Gas Mixtures ◽  
Mas Nmr ◽  
Significant Fraction ◽  
Zeolite A

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.

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