scholarly journals Influence of Composition and Plasma Power on Properties of Film from Biodegradable Polymer Blends

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1592 ◽  
Author(s):  
Leona Omaníková ◽  
Ján Bočkaj ◽  
Mirko Černák ◽  
Roderik Plavec ◽  
Jozef Feranc ◽  
...  
Keyword(s):  
Surface Energy ◽  
Plasma Treatment ◽  
Polar Component ◽  
Plasma Power ◽  
Surface Plasma ◽  
High Concentration ◽  
Plasma Device ◽  
Factor Design ◽  
The Difference ◽  
Acetyl Tributyl Citrate

The work is focused on the study of surface plasma treatment (DCSBD) of films from biodegradable polymers from renewable sources based on polylactic acid (PLA) and polyhydroxybutyrate (PHB). A 4-factor design of experiment was used where the selected variable parameters were the plasma device power, the time of plasma treatment, the ratio of PHB in the polymer blend with PLA, and the content of acetyl tributyl citrate (ATBC) plasticizer in the PLA + PHB blend. The surface total energy and the polar component were evaluated immediately after surface plasma treatment and after 5 h of sitting. Topography of foil surfaces was also studied by AFM. In terms of plasma power and activation time, the greatest increase in surface energy values was observed with a short plasma time of 2 s and a high power of 400 W. Increasing the content of ATBC in interaction with the high concentration of PHB in the blend results in a reduction in the difference of both the polar component and the total free surface energy.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

The Effect of T-Commerce Scarcity Messages and Price Policies on Attitudes and Purchase Intention

2019 ◽  
Vol 118 (1) ◽  
pp. 42-47
Author(s):  
KwangSeok Han
Keyword(s):  
Statistical Analysis ◽  
Purchase Intention ◽  
Time Limit ◽  
Discount Factor ◽  
Limited Time ◽  
Price Discount ◽  
Discount Price ◽  
Strategic Plans ◽  
Factor Design ◽  
The Difference

Background/Objectives: This study investigated differences in the attitude of users according to type of scarcity message and price discount conditions to compose T-commerce sales messages and search for effective strategic plans. Methods/Statistical analysis: This study empirically verifies the difference in promotion attitude and purchase intention between the type of T-Commerce scarcity message (quantity limit message / time limit message) and the price discount policy (price discount / non-discount) message. For this purpose, 2 (scarcity type: limited quantity, limited time) X 2 (with or without price discount: price discount, no price discount) factor design between subjects was used.

A look into the interaction of metal oxide thin films with biological media: Albumin and Fibrinogen adsorption

2012 ◽  
Vol 1376 ◽  
Author(s):  
P. Silva-Bermudez ◽  
S. Muhl ◽  
M. Rivera ◽  
S. E. Rodil
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Protein Adsorption ◽  
Photoelectron Spectroscopy ◽  
Ex Situ ◽  
Polar Component ◽  
Metal Oxide Thin Films ◽  
Adsorbed Protein ◽  
Major Chemical ◽  
Fibrinogen Adsorption

ABSTRACTIn the present work, the adsorption of albumin and fibrinogen on Ta, Nb, Ti and Zr oxidesthin films deposited on Si (100) wafers by magnetron sputtering was studied in order to get a better understanding of the correlation among the surface properties of these oxides and the protein adsorption phenomena on their surfaces. The surface energy, hydrophobicity, chemical composition, roughness and atomic order of the films were characterized. The films were immersedfor 45 minutes in single protein solutions; either albumin or fibrinogenand the adsorbed protein layer on the films was studied ex-situ in a dry ambient using bothX-ray photoelectron spectroscopy and atomic force microscopy.The adsorption of albumin and fibrinogen on the films modified the surface morphology and decreased the surface roughness for all the four different metal oxides. The XPS results confirmed the presence of the protein on the surface of the films and showed that the two proteins studied were adsorbed without undergoing a major chemical decomposition. A correlation between the surface roughness,the polar component of the surface energy of the films and the atomic percentage of nitrogen on the films after protein adsorption, an indirect signal of the amount of protein adsorbed, was found for albumin and fibrinogen adsorption on Ta, Nb and Ti oxides; the largest the roughness or the polar component the largest amount of adsorbed protein.

The centriolar complex isolated from starfish spermatozoa

1981 ◽  
Vol 49 (1) ◽  
pp. 33-49 ◽  
Author(s):  
R. Kuriyama ◽  
H. Kanatani
Keyword(s):  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Microtubule Assembly ◽  
High Concentration ◽  
Microtubule Organization ◽  
Sucrose Density Gradient Centrifugation ◽  
The Difference ◽  
Distal Centriole

Centrioles from spermatozoa of the starfish, Asterina pectinifera, were isolated and partially purified by solubilization of chromatin followed by sucrose density-gradient centrifugation. The ultrastructure of the isolated centriolar complex was investigated in whole mount preparations by electron microscopy. The complex unit was composed of a pair of centrioles and a pericentriolar structure, which associated with the distal end of the distal centriole by 9 spoke-like satellites extending radially to a marginal ring. Each satellite bifurcated at a dense node forming 2 fan-like shapes with a periodic striated pattern. The tubular structure of the centrioles easily disintegrated, leaving the pericentriolar structure or axonemal microtubules intact. The distal centriole in a spermatozoon served as an initiating site for flagellar microtubule assembly; that is, a number of “9 + 2′ axonemal tubules were observed adhering just beneath the distal end of the basal body. In experiments in vitro, polymerization of microtubule proteins purified from porcine brain was initiated by the structure at the ends of both proximal and distal centrioles, but not from the satellites or the marginal ring. Also, few if any microtubules were formed from the sides of each centriole, even in the presence of a high concentration of exogenous tubulin. On the other hand, centrioles of spermatozoa, when they were in mature ooplasm, could initiate the formation of sperm asters by microtubules. Therefore, centrioles in spermatozoa seem to be able to initiate microtubules in a 2 ways. A possible explanation of the difference between the 2 types of microtubule organization in vivo, i.e. in the sperm cell itself and in the ooplasm, it discussed.

Photodosimeter Badge System

PEDIATRICS ◽  
1985 ◽  
Vol 75 (2) ◽  
pp. 437-441
Author(s):  
Peter C. Scheidt ◽  
Phyllis M. Sternthal ◽  
Robert Anderson ◽  
Robert Studholme ◽  
Dolores A. Bryla ◽  
...  
Keyword(s):  
Child Health ◽  
Human Development ◽  
Optical Density ◽  
Action Spectrum ◽  
Radiant Energy ◽  
National Academy Of Sciences ◽  
High Concentration ◽  
Film Badge ◽  
The Difference ◽  
Academy Of Sciences

The Committee on Phototherapy in the Newborn of the National Academy of Sciences has recommended10 development of a compact system to continuously measure radiant energy exposure of infants treated with phototherapy. A small bilirubinimpregnated photodosimeter film badge was developed by the Beckman Instrument Company for this purpose and was used during the National Institute of Child Health and Human Development (NICHD) phototherapy study. This report summarizes the results of data obtained with this measurement device and briefly describes the performance of this system. METHODS The film badge dosimeter system consists of a 5.2x2.6-cm plastic badge composed of an imbedded disk of bilirubin cast in a polymeric substrate and sandwiched between two layers of clear plastic. Before exposure to light, the badge exhibits a high optical density at 460 nm due to a relatively high concentration of bilirubin. The optical density of the badge at 400 to 500 nm decreases as a function of the total dose of light within the action spectrum for the photodecomposition of bilirubin to which the badge has been exposed. Initial optical density at 460 nm is measured by a densitometer designed and dedicated specifically for this purpose. After exposure, the optical density is again measured by insertion into the densitometer; the total dosage, which is the time-integrated irradiance received by the badge during the photodecomposition process, is derived from the difference in optical density between the two readings. (A description of the calibration of the badge is available on request from Biometry Branch, Epidemiology and Biometry Research Program, National Institute of Child Health and Human Development, Bethesda, Maryland.)

scholarly journals Occurrence and correlation between the numbers of Black-headed Gull Chroicocephalus ridibundus and Yellow-legged Gull Larus michahellis on Kolut fish ponds (Serbia)

2015 ◽  
Vol 84 (1) ◽  
pp. 37
Author(s):  
Marko Tucakov ◽  
Milan Vogrin
Keyword(s):  
Food Availability ◽  
Fish Ponds ◽  
Early Winter ◽  
High Food ◽  
High Concentration ◽  
Aquatic Animals ◽  
Autumn Period ◽  
Larus Michahellis ◽  
The Difference ◽  
Fish Harvest

Presence and correlation between the numbers of Black-headed and Yellow-legged Gull was studies between 1998 and 2004 on Kolut fishponds in NW Serbia. Both species occurred there from February to December. Spring migration culminated in late February and early March. The period of the most intensive autumn concentration was from October to December. The difference between the numbers in all months as well as between the numbers in spring and in autumn was statistically significant. The period of the most intensive autumn passage of Yellow-legged Gull was from late October to early December. The difference between the numbers between the months was not statistically significant. A high concentration of both species in autumn and early winter was explained by high food availability during fish harvest when ponds were empty. Positive correlation between the numbers of two species thru the year indicated attractiveness of large flocks of Black-headed Gulls for Yellow-legged Gulls. This is especially true for the autumn period, when feeding niches and food is easily accessible. Correlation between the numbers of two species was negative in spring, when accesibility of aquatic animals is lower and large flocks of Black-headed Gulls are lacking.

Influence of argon plasma treatment on carbon fibre reinforced high performance thermoplastic composite

2020 ◽  
pp. 095400832095706
Author(s):  
Jennifer Vinodhini ◽  
K Sudheendra ◽  
Meera Balachandran ◽  
Shantanu Bhowmik
Keyword(s):  
Mechanical Properties ◽  
Contact Angle ◽  
Surface Energy ◽  
Carbon Fibre ◽  
Plasma Treatment ◽  
Dynamic Contact Angle ◽  
Argon Plasma ◽  
Dynamic Contact ◽  
Resin Matrix ◽  
Surface Modified

This investigation highlights argon plasma treatment on Poly-aryl-ether-ketone (PAEK) and carbon fibre (CF) surface. The PAEK and CF surface is modified for 300 sec and the change in physiochemical and mechanical properties were investigated through Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Contact angle, Atomic Force Microscope (AFM) and Tensile Test. FTIR of surface modified PAEK revealed the stretching of C-H, C=C and C=O functional groups. A reversal phenomenon of increased surface energy was observed through dynamic contact angle study of CF and to further examine the surface energy effect, AFM analysis on CF was carried out revealing increased roughness with numerous micro dents formation. PAEK/CF composite samples were fabricated through compression moulding technique. The change in mechanical properties due to surface modification were analysed through Tensile testing on surface modified PAEK/CF sample and untreated PAEK/CF samples. The surface treated PAEK/CF showed increased tensile strength than untreated PAEK/CF. The argon plasma treatment helped in creating depth striations that lead to better interlocking of resin matrix with the reinforced CF. The fracture surface was examined through Filed Emission Scanning Electron Microscope (FE-SEM) wherein the Micrographs of the tensile tested samples indicated failure of composite due to fibre breakage.

scholarly journals Bottom-up versus top-down factor investing: an alpha forecasting perspective

2020 ◽  
Author(s):  
Martin Zurek ◽  
Lars Heinrich
Keyword(s):  
Interaction Effects ◽  
Informational Content ◽  
Firm Characteristics ◽  
Recent Discussion ◽  
High Concentration ◽  
Top Down ◽  
Bottom Up ◽  
Factor Investing ◽  
Significant Performance ◽  
The Difference

AbstractIn a recent discussion about efficient ways to combine multiple firm characteristics into a multifactor portfolio, a distinction was made between the bottom-up and top-down approach. Both approaches integrate characteristics with equal weights and ignore interaction effects from differences in informational content and correlations between the firm characteristics. The authors complement the bottom-up approach for the missing interaction effects by implementing a linear alpha forecasting framework. Bottom-up versus top-down factor investing is typically discussed using the assumption that all characteristics are equally priced, but the pricing impact of different firm characteristics can vary tremendously. The alpha forecasting perspective provides a theoretical motivation for factor investing and helps to compare the bottom-up and top-down approach with regard to the difference of informational content and interaction effects between firm characteristics. Taking into account the difference in informational content between firm characteristics leads to significant performance improvement in factor models with a high concentration of informational content. Equally weighted characteristics result in related performance irrespective of whether the bottom-up or top-down approach is applied.

scholarly journals Comparison of three methods for rendering plant fat transesterification

2013 ◽  
Vol 59 (No. 2) ◽  
pp. 51-55
Author(s):  
A. Prošková ◽  
J. Kučera ◽  
Z. Kopicová ◽  
L. Škarková
Keyword(s):  
Fatty Acids ◽  
Free Acid ◽  
The Other ◽  
Alkaline Media ◽  
Optimum Temperature ◽  
Optimum Conditions ◽  
High Concentration ◽  
Reaction Velocity ◽  
Catalysed Reaction ◽  
The Difference

Three most frequently used methods for fat transesterification were compared using rendering plant fat (RPF) as model. Acid-catalysed transesterification was found to be the most effective (conversion 90%) at optimum conditions (fat: methanol ratio 1:10, sulphuric acid amount of 2% v/v, temperature 95°C). Base-catalysed transesterification of RPF on the other hand, results in much lower conversion (45%) at optimum conditions (fat:methanol ratio 1:20, NaOH amount 8% w/v, optimum temperature 95°C). The difference is done (among others) by the fact that RPF has high concentration of free acid (high acidity number) compared with the fats usually used for transesterification and that free acids are not esterified in alkaline media. Enzyme-(lipase) catalysed reaction could lead to partial esterification of free fatty acids, but with much lower reaction velocity. This fact leads to higher conversion in the case of enzyme-catalysed transesterification of RPF compared with base-catalysed reaction; nevertheless, even in this case the conversion is much lower in comparison with acid-catalysed reaction. The optimum conversion in enzyme-catalysed reaction was 55%.  

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