scholarly journals РОЗРИВАЛЬНІ ХАРАКТЕРИСТИКИ КОМПЛЕКСНОЇ ПОЛІЕТИЛЕНОВОЇ НИТКИ

2022 ◽  
pp. 51-59
Author(s):  
SVITLANA BOBROVA ◽  
OKSANA DMYTRYK ◽  
LIUDMYLA HALAVSKA ◽  
TETIANA YELINA
Keyword(s):  
Linear Density ◽  
Materials Science ◽  
Breaking Load ◽  
Breaking Force ◽  
Factors Affecting ◽  
Textile Materials ◽  
Modeling Systems ◽  
Analysis And Synthesis ◽  
Straight Segments

Purpose. To investigate the influence of the number of threads resisting to break, the griping length, and the change in the position of the interlacing point when threading with a loop the breaking characteristics of complex polyethylene threads in the form of a loop.Methodology. In the course of the research, experimental research methods were used to determine the breaking characteristics of high molecular weight polyethylene threads on a WDW-5ES tensile machine in accordance with DSTU ISO 2062: 2004, the main provisions of textile materials science and knitting theory, methods of analysis and synthesis of the results obtained. Results. Based on the results of the studies, the influence of different factors on the breaking characteristics of complex multifilament threads was determined, namely: the influence of the number of threads resting on the break, the griping length and the change in the position of the weave point when threading with a loop. In the course of research, the griping length was changed in the range from 25mm to 300mm, and with a stable griping length (100 mm), the location of the thread weave point relative to the lower grip (25mm, 50mm, 75mm) was changed. It has been found that the breaking characteristics of a complex polyethylene yarn are influenced by both the griping length and the location of the weave point in the case of a loop-shaped break. The magnitude of the specific breaking force in the study of loop-shaped rupture is greater than in the study of straight segments of the thread. This is due to parallelization and compaction of the filaments due to the presence of the weave point on the thread that resists tearing. Scientific novelty. Regularities of the effect of griping length, linear density, and location of the point of weave of the complex high molecular threads in relation to the downer and upper grip are established provided that the griping length (100 mm) remains unchanged on the value of breaking load and elongation.Practical significance. Determination of the factors affecting the breaking characteristics of a complex polyethylene yarn will allow in the future, at the stage of designing the structure of knitwear in computer 3D modeling systems, to provide for the magnitude of the breaking force.

scholarly journals ОЦІНКА ПОКАЗНИКІВ КОМФОРТНОСТІ БІЛИЗНЯНИХ ТРИКОТАЖНИХ ПОЛОТЕН ДЛЯ ЗАНЯТЬ СПОРТОМ

2019 ◽  
Vol 136 (4) ◽  
pp. 106-114
Author(s):  
С. І. Арабулі ◽  
А. Т. Арабулі ◽  
С. С. Ототюк ◽  
В. В. Клочко ◽  
Д. Ю. Черепенко
Keyword(s):  
Physical Properties ◽  
Materials Science ◽  
Experimental Studies ◽  
Basic Principles ◽  
Textile Materials ◽  
Clothing Comfort ◽  
Modern Methods

Determination  of  comfort properties  of  knitted  underwear for  sports and  comparison  of traditional and innovative underwear for thermal underwear. Methodology.  The  article  provides  an  analysis  of  the  modern  range  of  textile  materials  for underwear, analyzes the latest developments in the design of thermal underwear. The modern methods have been used to determine clothing comfort and physical properties of textile materials. Experimental studies are based on the basic principles of textile materials science.

scholarly journals Behavior of Polymer Materials Exposed to Aging in the Swimming Pool: Focus on Properties That Assure Comfort and Durability

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2414
Author(s):  
Ivana Salopek Čubrić ◽  
Goran Čubrić ◽  
Vesna Marija Potočić Matković
Keyword(s):  
Fluid Transport ◽  
Negative Impact ◽  
Microscopic Analysis ◽  
Tensile Tests ◽  
Polymer Materials ◽  
Breaking Force ◽  
Textile Materials ◽  
Few Data ◽  
Effects Of Aging

The degradation of polyamide (PA) and polyester (PES) polymers is under intense study due to growing concerns about the accumulation of plastics in soils and oceans. Previous studies confirm that ageing degrades PA and PES at the molecular level. However, researchers have not addressed the development of protocols for aging textile materials in swimming pools, and few data are available on the effects of aging on comfort and durability. This research addresses the development of the aging protocol for PA and PES swimwear materials, its implementation, and the evaluation of properties that assure comfort and durability after specific periods of exposure. The tests include microscopic analysis, tensile tests, determination of fluid transport phases and drying period. The results revealed changes in the surface of the material in terms of fibrillation (more pronounced after outdoor aging). There is a positive correlation between the exposure duration and the breaking force (R2 ranges from 0.85 to 0.98), with a stronger correlation for the PA materials. The decrease in breaking force due to aging is up to 40%, indicating significantly reduced durability. The change in breaking force follows the changes in mass (R2 = 0.867). In terms of comfort assurance, outdoor aging of materials should have a greater negative impact than indoor ageing.

Determination of interface width using EELS fine structure changes

1991 ◽  
Vol 49 ◽  
pp. 730-731
Author(s):  
Vinayak P. Dravid ◽  
M.R. Notis ◽  
C.E. Lyman
Keyword(s):  
Fine Structure ◽  
Materials Science ◽  
Input Parameter ◽  
Core Loss ◽  
Directionally Solidified ◽  
Interface Width ◽  
Structure Changes ◽  
Important Input ◽  
Directionally Solidified Eutectics

The concept of interfacial width is often invoked in many materials science phenomena which relate to the structure and properties of internal interfaces. The numerical value of interface width is an important input parameter in diffusion equations, sintering theories as well as in many electronic devices/processes. Most often, however, this value is guessed rather than determined or even estimated. In this paper we present a method of determining the effective structural and electronic- structural width of interphase interfaces using low- and core loss fine structure effects in EELS spectra.The specimens used in the study were directionally solidified eutectics (DSEs) in the system; NiO-ZrO2(CaO), NiO-Y2O3 and MnO-ZrO2(ss). EELS experiments were carried out using a VG HB-501 FE STEM and a Hitachi HF-2000 FE TEM.

The many faces of STEM in materials science

1991 ◽  
Vol 49 ◽  
pp. 440-441
Author(s):  
John Silcox
Keyword(s):  
Materials Science ◽  
Auger Spectroscopy ◽  
Dark Field ◽  
High Tc Superconductors ◽  
High Tc ◽  
Acoustic Environment ◽  
Electromagnetic Vibration ◽  
The Many ◽  
Serial Mode

Determination of the microstructure and microchemistry of small features often provides the insight needed for the understanding of processes in real materials. In many cases, it is not adequate to use microscopy alone. Microdiffraction and microspectroscopic information such as EELS, X-ray microprobe analysis and Auger spectroscopy can all contribute vital parts of the picture. For a number of reasons, dedicated STEM offers considerable promise as a quantitative instrument. In this paper, we review progress towards effective quantitative use of STEM with illustrations drawn from studies of high Tc superconductors, compound semiconductors and metallization of H-terminated silicon.Intrinsically, STEM is a quantitative instrument. Images are acquired directly by detectors in serial mode which is particularly convenient for digital image acquisition, control and display. The VG HB501A at Cornell has been installed in a particularly stable electromagnetic, vibration and acoustic environment. Care has been paid to achieving UHV conditions (i.e., 10-10 Torr). Finally, it has been interfaced with a VAX 3200 work station by Kirkland. This permits, for example, the acquisition of bright field (or energy loss) images and dark field images simultaneously as quantitative arrays in perfect registration.

Modeling of dynamic mosaicism on ring chromosomes in human fibroblasts and IPSCS

2020 ◽  
pp. 12-13
Author(s):  
Т.В. Никитина ◽  
А.А. Кашеварова ◽  
М.М. Гридина ◽  
А.А. Хабарова ◽  
А.Г. Мензоров ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Human Fibroblasts ◽  
Cellular Heterogeneity ◽  
Mitotic Stability ◽  
Factors Affecting ◽  
Ring Chromosomes ◽  
Cell Clones ◽  
Mitotic Instability ◽  
Mitotic Behavior

Митотическая нестабильность кольцевых хромосом может приводить к появлению клеточных клонов с различной генетической структурой. В качестве модели нестабильности кольцевых хромосом в митозе мы использовали фибробласты от пациентов с r(8), r(13), r(18) и r(22) и полученные из них индуцированные плюрипотентные стволовые клетки (ИПСК). Линии ИПСК с r(22) имели относительно стабильный кариотип на протяжении десятков (до 60) пассажей и сохраняли неизменную структуру кольцевой хромосомы. Кариотип линий ИПСК с r(8) и r(18) на ранних пассажах стабильный, планируется его изучение на поздних пассажах. Наибольшее разнообразие кариотипа выявлено в линиях ИПСК с r(13), в которых наблюдали различные перестройки и выраженную клеточную гетерогенность. Определение факторов, влияющих на митотическую стабильность кольцевых хромосом, может иметь значение для консультирования пациентов. Mitotic instability of ring chromosomes can lead to the appearance of cell clones with different genetic structure. IPSCs from fibroblasts of patients with r(8), r(13), r(18), and r(22) were used as a model of ring chromosomes mitotic behavior. Karyotypes of iPSC lines with r(8) and r(18) have so far been evaluated only in the early passages, lines with r(22) have maintained a relatively stable karyotype up to 60 passages. The occurrence of rearrangements and cellular heterogeneity was found characteristic for r(13) iPSCs. The determination of factors affecting the ring chromosomes mitotic stability would be beneficial for the patient’s prognosis.

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