scholarly journals Effect of Solvent Treatment on Siro and Ring Spun TFO Polyester Yarn

Tekstilec ◽  
2021 ◽  
Vol 64 (1) ◽  
pp. 47-54
Author(s):  
Madan Lal Regar ◽  
◽  
Akhtarul Islam Amjad ◽  
Shubham Joshi ◽  
◽  
...  

Yarns and fabrics can be improved through structural modifications. Using an organic solvent is a novel and popular approach for a structural modification in the field of textiles. In the present work, Siro-spun® and TFO (Two for one Twisters) polyester yarns were modified with a solvent-acid mixture of aceton and trichloroacetic acid : methylene chloride (TCAMC). Both types of yarn samples were treated in a relaxed state with various concentrations of the solvent’s mixture at room temperature. The influence of the treatment with respect to linear density and TCAMC concentration on mechanical properties was investigated. Modified yarns exhibited higher breaking elongation, improved abrasion resistance and lower tenacity. It was also found that the methods of yarn manufacturing contribute significantly to the tensile behaviour of modified yarns. The improvement in elongation was higher in the treated TFO yarn. The abrasion resistance index was found to be lower in the case of siro polyester yarns. Furthermore, significant mass loss in yarn was observed after the treatment of TCAMC.

Author(s):  
Ladislav Rolník ◽  
Milan Naď

Abstract The contribution is mainly focused on research and development of structural modification of machine tools, lathes in particular. The main aim of the modification is to change the modal properties (mode shapes, natural frequencies) of the lathe tool. The main objective of the contribution will be to formulate, mathematical analyse and evaluate the proposed methods and procedures for structural modifications of the tool, represented by beam body. A modification of modal properties by insertion of beam cores into beam body is studied in this paper. In this paper, the effect of material properties and geometrical parameters of reinforcing cores on natural frequencies of beam body is presented. The implementation will bring benefit on machine productivity, decreasing the machine tool wear and in many cases it will lead to better conditions in the cutting process.


2020 ◽  
Author(s):  
Matiss Ozols ◽  
Alexander Eckersley ◽  
Kieran T Mellody ◽  
Venkatesh Mallikarjun ◽  
Stacey Warwood ◽  
...  

AbstractAlthough dysfunctional protein homeostasis (proteostasis) is a key factor in many age-related diseases, the untargeted identification of structural modifications in proteins remains challenging. Peptide location fingerprinting is a proteomic analysis technique capable of identifying structural modification-associated differences in mass spectrometry (MS) datasets of complex biological samples. A new webtool (Manchester Peptide Location Fingerprinter), applied to photoaged and intrinsically aged skin proteomes, can relatively quantify peptides (spectral counting) and map statistically significant differences to regions within protein structures. New photoageing biomarkers were identified in multiple proteins including matrix components (collagens and proteoglycans), oxidation and protease modulators (peroxiredoxins and SERPINs) and cytoskeletal proteins (keratins). Crucially, for many extracellular biomarkers, structural modification-associated differences were not correlated with relative abundance (by ion intensity). By applying peptide location fingerprinting to published MS datasets, (identifying biomarkers including collagen V and versican in ageing tendon) we demonstrate the potential of the MPLF webtool to discover novel biomarkers.


2021 ◽  
Author(s):  
Theo Jenk ◽  
Daniela Festi ◽  
Margit Schwikowski ◽  
Valter Maggi ◽  
Klaus Oeggl

<p>Dating glaciers is an arduous yet essential task in ice core studies, which becomes even more challenging for the dating of glaciers suffering from mass loss in the accumulation zone as result of climate warming. In this context, we present the dating of a 46 m deep ice core from the Central Italian Alps retrieved in 2016 from the Adamello glacier (Pian di Neve, 3100 m a.s.l.). We will show how the timescale for the core could be obtained by integrating results from the analyses of the radionuclides <sup>210</sup>Pb and <sup>137</sup>Cs with annual layer counting derived from pollen and refractory black carbon concentrations. Our results clearly indicate that the surface of the glacier is older than the drilling date of 2016 by about 20 years and that the 46 m ice core reaches back to around 1944. Despite the severe mass loss affecting this glacier even in the accumulation zone, we show that it is possible to obtain a reliable timescale for such a temperate glacier. These results are very encouraging and open new perspectives on the potential of such glaciers as informative palaeoarchives. We thus consider it important to present our dating approach to a broader audience.</p>


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5500
Author(s):  
Bindhu Alappat ◽  
Jayaraj Alappat

Anthocyanins are polyphenol compounds that render various hues of pink, red, purple, and blue in flowers, vegetables, and fruits. Anthocyanins also play significant roles in plant propagation, ecophysiology, and plant defense mechanisms. Structurally, anthocyanins are anthocyanidins modified by sugars and acyl acids. Anthocyanin colors are susceptible to pH, light, temperatures, and metal ions. The stability of anthocyanins is controlled by various factors, including inter and intramolecular complexations. Chromatographic and spectrometric methods have been extensively used for the extraction, isolation, and identification of anthocyanins. Anthocyanins play a major role in the pharmaceutical; nutraceutical; and food coloring, flavoring, and preserving industries. Research in these areas has not satisfied the urge for natural and sustainable colors and supplemental products. The lability of anthocyanins under various formulated conditions is the primary reason for this delay. New gene editing technologies to modify anthocyanin structures in vivo and the structural modification of anthocyanin via semi-synthetic methods offer new opportunities in this area. This review focusses on the biogenetics of anthocyanins; their colors, structural modifications, and stability; their various applications in human health and welfare; and advances in the field.


1981 ◽  
Vol 59 ◽  
pp. 345-346
Author(s):  
A. Harpaz ◽  
A. Kovetz

The evolution of a 1.2Mʘ star along the asymptotic branch with continuous mass loss is presented, showing that this mass loss leads to the formation of a PN with a typical central star in its center.A former investigation (Harpaz and Kovetz, 1980) has shown that mechanisms for PN creation based on sudden violent processes are not likely to work in the envelope of a red giant star. On the other hand, significant mass loss from red giants was observed as a general phenomenon.We have followed the evolution of a 1.2Mʘ star along the asymptotic branch, including in the evolutionary calculations a mass loss according to Reimers’ empirical formula. It was found that towards the end of this stage, the mass loss rate was about 2.7xl0-6Mʘ/y, which is consistent with the formation of a typical PN within 30,000 years. When the mass content of the hydrogen rich envelope dropped to 1.5x10-3Mʘ, the star began to contract rapidly, forming a typical central star of 0.6Mʘ


1999 ◽  
Vol 77 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Pierre Lachapelle ◽  
Olga Dembinska ◽  
Luz Marina Rojas ◽  
Julie Benoit ◽  
Guillermina Almazan ◽  
...  

Previous studies have shown that newborn rats exposed postnatally to hyperoxia will develop a permanent impairment of the retinal function as determined with the electroretinogram (ERG). The purpose of our study was to examine whether postnatal hyperoxia equally alters the light- and dark-adapted ERGs and oscillatory potentials (OPs) as well as leads to permanent structural modification of the retina. During the first 14 days of life, cohorts of Sprague-Dawley rats were exposed to a hyperoxic environment, and ERGs were recorded at mean ages of approximately 25 and 55 days. Our results indicate that both light- and dark-adapted ERGs and OPs are already significantly altered within a few days following exposure to hyperoxia. None of the ERG and (or) OP parameters, with the exception of the a-wave, returned to normal values by 55 days of age. In fact some dark-adapted OPs were completely abolished following postnatal O2 exposure. Histological analysis revealed that the retina of rats exposed to hyperoxia failed to develop an outer plexiform layer and had a reduced count of horizontal cells, consistent with the permanent postreceptoral anomalies seen in the ERG responses. Our results suggest that postnatal hyperoxia causes a generalized retinal disorder leading to permanent structural modifications of the retinal cytoarchitecture and lasting anomalies of the rod and cone functions.Key words: rods, cones, electroretinography, oscillatory potentials, hyperoxia, retina, development.


2019 ◽  
Vol 13 (1) ◽  
pp. 26
Author(s):  
Suherna Suherna ◽  
Patunru P ◽  
Maspah Maspah

Improved quality, strength and life time in terms of abrasion resistance on safety shoes outsole Cheetah material where the process use of some material has decreased in quality, besides due to usage factors, maintenance factors, and some of these materials also experience problems during use. This study is done to determine the abrasion resistance of each Outsole Polyurethane (PU) material and Nitrile Butadiene Rubber (NBR). Abrasion resistance test on the material method used the DIN Abrasion tester. Retrieval of data on outsole material was carried out on the outsole material with new conditions and that has been used in the field for a period of 1 year with a method of measuring abrasion resistance index and density of material. Calculation of average abrasion resistance for new Polyurethane (PU) type was 37 , 11 mm3 / year, while the average abrasion resistance for Polyurethane (PU) type that has been used for 1 year was 33.19 mm3 / year so that the difference is 3.92 mm3 / year or about 11% quality decrease of abrasion resistance. The average abrasion resistance with the new Nitrile Butadiene Rubber (NBR) type was 108.26 mm3 / year, the average abrasion resistance for Nitrile Butadiene Rubber (NBR) type with conditions already used in 1 year period was 107.44 mm3 / year so that the difference is 0.82 mm3 / year or about 1% decrease in quality decrease of abrasion resistance. Abrasion tolerance limits that have been set according to the SOP (Standard Operational Procedure) against abrasion resistance if SG ≥ 0.9 then the Abrasive Max is 150 and if SG ≤ 0.9 Then the Abrasive Max is 250.


1988 ◽  
Vol 34 (118) ◽  
pp. 283-290 ◽  
Author(s):  
Richard B. Alley

AbstractDepth hoar in polar firn forms when large temperature gradients act on low-density firn, but high-density firn does not develop into depth hoar. Low densities in firn may be depositional (burial of surface hoar or still-air snowfall) or diagenetic (mass loss to the free atmosphere, typically in autumn); however, diagenesis is sufficiently strong to cause significant mass loss only in the top 50–100 mm of firn. Between about 50–100 mm and 2 m depth, grain growth and densification are accelerated strongly by temperature-gradient effects; from 2 to 5 m, temperature gradients have a small but measurable effect on rates of processes in firn, and below 5 m rates essentially have isothermal values.Diagenetic depth-hoar layers typically develop in the autumn, are relatively thick, and have smooth bases. Depositional depth-hoar layers may develop at any season, are relatively thin, and have irregular bases. In low-accumulation regions, visual stratification may preserve only an annual signal, but in high-accumulation regions individual storms or other features may be recognizable.


2019 ◽  
Vol 43 (41) ◽  
pp. 16281-16299 ◽  
Author(s):  
Rajkumar Reddyrajula ◽  
Udaya Kumar Dalimba

New imidazo[1,2-a]pyridine/pyrimidine-1,2,3-triazoles (IPTs) designed by specific structural modifications of zolpidem exhibited superior antitubercular activity than the parent compound.


Author(s):  
David A. Armstrong ◽  
Suichu Luo ◽  
David C. Joy

Radiation damage to organic specimens is the major limiting factor in high resolution electron microscopy studies of biological systems. Electron beam irradiation compromises resolution by altering chemical microstructure, resulting in local mass loss and volume shrinkage in a specimen. All significant mass loss is thought to occur prior to a total incident dose of 50 electrons/ square angstrom If this is the case it is hard to reconcile the observation that images must be recorded at doses of less than 100 el/Å in order to avoid excessive mass loss and shrinkage while microanalytical (EDS and EELS) studies of the same tissue are routinely carried out at doses of 104 - 105el/Å2. Also, since most workers typically use either low dose (for imaging) or high dose (for microapalysis) there are apparently no studies in the literature which attempt to follow the process of radiation damage between these two extremes.We have chosen to investigate mass loss in polymer embedding resins such as are routinely used for TEM imaging as well as for X ray microanalytical applications.


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