THE PHYSICAL PROPERTIES OF SPIDER'S SILK AND THEIR ROLE IN THE DESIGN OF ORB-WEBS

1976 ◽  
Vol 65 (2) ◽  
pp. 483-506 ◽  
Author(s):  
MARK DENNY
Keyword(s):  
Amino Acids ◽  
Physical Properties ◽  
Breaking Stress ◽  
Structural Elements ◽  
Extension Ratio ◽  
Shock Absorbers ◽  
Orb Web ◽  
Degree Of Crystallization ◽  
Minimum Expenditure

1. Determinations were made of several physical properties of the viscid and frame silks of the orb-webs built by the spider Araneus sericatus (Cl.). 2. Both types of silk show a breaking stress of approximately 1 GN/m2 and an initial resilience of approximately 0.35. 3. The breaking extension ratio of viscid silk (λ = 3.00) is much greater than that of frame silk (λ = 1.25), and the viscid silk relaxes to a relatively greater extent. 4. These properties are correlated with the degree of crystallization of the protein from which the silk is made, this factor being controlled by the sequence of amino acids in the protein. 5. The physical properties of the viscid and frame silks allow them to function effectively as shock absorbers and structural elements, respectively; and allow the orb-web to function as an aerial filter with a minimum expenditure of material and energy.

Studies on the Development of Benzoyl Peroxide Catalysed Rapid Oil Tanning using Linseed Oil

2021 ◽  
Vol 116 (7) ◽  
Author(s):  
Bindia Sahu ◽  
Jaya Prakash Alla ◽  
Gladstone Christopher Jayakumar
Keyword(s):  
Amino Acids ◽  
Tensile Strength ◽  
Physical Properties ◽  
Water Absorption ◽  
Benzoyl Peroxide ◽  
Special Class ◽  
Linseed Oil ◽  
Tanning Process ◽  
Remarkable Reduction ◽  
Better Than

Leather tanning is a stabilisation process of skin fibers. This is achieved by the interaction of collagen amino acids with tanning agents to stabilise skin from putrefaction. Tanning of collagen with oil is a special class of tanning known as chamois tanning. Chemically, the oil tanning involves oxidation of unsaturation present in the oil, which is generally achieved by exposing oil treated skins to air. In this study, Benzoyl peroxide has been used as an accelerating agent for oxidation of unsaturated bonds present in the linseed oil for oil tanning process. Results shows remarkable reduction in tanning duration from fifteen days to two days. The chamois leathers prepared using oxidation accelerant (Benzoyl peroxide) have been evaluated for physical properties such as water absorption (611%), tensile strength (18 N/mm2) and percentage of elongation (66 %) which are found to be better than control leathers.

A Pyoverdin from the Antarctica Strain 51W of Pseudomonas fluorescens

1999 ◽  
Vol 54 (3-4) ◽  
pp. 156-162 ◽  
Author(s):  
Jessica Voss ◽  
Kambiz Taraz ◽  
Herbert Budzikiewicz
Keyword(s):  
Amino Acids ◽  
Pseudomonas Fluorescens ◽  
Binding Sites ◽  
Chemical Shifts ◽  
Chemical Degradation ◽  
Spectroscopic Methods ◽  
Extreme Conditions ◽  
Structural Elements ◽  
Nmr Data ◽  
Schirmacher Oasis

From the strain 51W of Pseudomonas fluorescens living under extreme conditions at the Schirmacher Oasis (Antarctica) a pyoverdin was obtained. Its structure was elucidated by chemical degradation and spectroscopic methods. The NMR data of the pyoverdin and of its Ga(III) complex were compared. Appreciable influences of the metal on the chemical shifts of the atoms at its binding sites were observed. Thus the structural elements involved in the complexation can be identified and coinciding signals of amino acids occurring more than once in the peptide chain can be separated.

scholarly journals ANALISYS OF THE INFLUENCE OF GLUE JOINTS ON THE MEASUREMENT OF PHYSICAL PROPERTIES OF STRUCTURAL ELEMENTS USING FIBER BRAGG GRATING

2020 ◽  
Vol 10 (3) ◽  
pp. 99-102
Author(s):  
Tomasz Zieliński ◽  
Łukasz Zychowicz
Keyword(s):  
Stainless Steel ◽  
Physical Properties ◽  
Fiber Bragg Grating ◽  
Transmission Spectrum ◽  
Measuring Transducer ◽  
Bragg Grating ◽  
Transmission Characteristic ◽  
Test Results ◽  
Structural Elements ◽  
Factors Affecting

The research presents the analysis of the influence of the glue connection on the measurement of elongation of stainless steel and aluminum samples by means of fiber Bragg grating (FBG) with uniform fibers used as a measuring transducer. Research indicates two possible factors affecting the deformation of the transmission spectrum obtained during elongation measurement. One of them is the type of adhesive that is used to make the connection between the fiber Bragg grating and the tested sample. The second possible factor is method of connection's execution. The need for research on glue connection resulted from the formation of defects mainly in the form of numerous side bands visible in the transmission spectrum during the measurement of elongations. The test results were presented in the form of graphs obtained on the basis of transmission characteristic.

Metallic Foams Obtained from Nickel Based Superalloy Hollow Spheres

2011 ◽  
Vol 672 ◽  
pp. 141-144 ◽  
Author(s):  
Ioan Vida-Simiti ◽  
Nicolaie Jumate ◽  
Emil Bruj ◽  
Niculina Sechel ◽  
György Thalmaier ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Catalyst Support ◽  
Hollow Spheres ◽  
High Porosity ◽  
Structural Elements ◽  
Metallic Foams ◽  
Hollow Particles ◽  
Nickel Based Superalloy ◽  
Shock Absorbers ◽  
Thermal Barriers

In this work, hollow spherical nickel based superalloy powders obtained by liquid phase atomization were used. The obtained powder was divided into six size particle ranges between 200 µm and 630 µm using a shatter box. Samples from all six ranges were obtained by spreading the powder into the sintering die and consolidating them by sintering at 900°C and 1000°C for 30 minutes in vacuum (10-4 Torr). The metallic foams obtained by sintering hollow particles presents high porosity, and can be used as thermal barriers, catalyst support, shock absorbers or lightweight structural elements.

Co-assembly of helical β3-peptides: a self-assembled analogue of a statistical copolymer

2017 ◽  
Vol 89 (12) ◽  
pp. 1809-1816 ◽  
Author(s):  
Claire Buchanan ◽  
Christopher J. Garvey ◽  
Patrick Perlmutter ◽  
Adam Mechler
Keyword(s):  
Amino Acids ◽  
Physical Properties ◽  
Self Assembly ◽  
Unnatural Amino Acids ◽  
The Self ◽  
Microscopy Imaging ◽  
Wide Range ◽  
Self Assembled ◽  
Unnatural Peptides ◽  
Natural Amino Acids

AbstractUnnatural peptide self-assembly offers the means to design hierarchical nanostructures of controlled geometries, chemical function and physical properties. N-acyl β3 peptides, where all residues are unnatural amino acids, are able to form helical fibrous structures by a head-to-tail assembly of helical monomers, extending the helix via a three point supramolecular hydrogen bonding motif. These helical nanorods were shown to be stable under a wide range of physical conditions, offering a self-assembled analogue of polymeric fibres. Hitherto the self-assembly has only been demonstrated between identical monomers; however the self-assembly motif is sequence-independent, offering the possibility of hetero-assembly of different peptide monomers. Here we present a proof of principle study of head-to-tail co-assembly of two different helical unnatural peptides Ac-β3[WELWEL] and Ac-β3[LIA], where the letters denote the β3 analogues of natural amino acids. By atomic force microscopy imaging it was demonstrated that the homo-assembly and co-assembly of these peptides yield characteristically different structures. Synchrotron small angle X-ray scattering experiments have confirmed the presence of the fibres in the solution and the averaged diameters from modelled data correlate well to the results of AFM imaging. Hence, there is evidence of co-assembly of the fibrous superstructures; given that different monomers may be used to introduce variations into chemical and physical properties, the results demonstrate a self-assembled analogue of a statistical co-polymer that can be used in designing complex functional nanomaterials.

Preparation of some long-chain N-acyl derivatives of essential amino acids for nutritional studies

1980 ◽  
Vol 58 (7) ◽  
pp. 573-576 ◽  
Author(s):  
Alenka Paquet
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Physical Properties ◽  
Essential Amino Acids ◽  
Nutritional Studies ◽  
Derivatives Of ◽  
Acyl Derivatives ◽  
Long Chain

Long-chain N-acyl derivatives of methionine, tryptophan, threonine, and lysine (N6) have been obtained by the reaction of succinimidyl esters of fatty acids with the unprotected amino acids. Their physical properties have been characterized.

Changes with aging in the levels of amino acids in rat CNS structural elements I. Glutamate and related amino acids

1989 ◽  
Vol 14 (6) ◽  
pp. 555-562 ◽  
Author(s):  
M. Banay-Schwartz ◽  
A. Lajtha ◽  
M. Palkovits
Keyword(s):  
Amino Acids ◽  
Structural Elements ◽  
Rat Cns
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