scholarly journals Impact of Laser Intensities at Various DPI and Pixel Time on the Properties of Denim Garments

2021 ◽  
Vol 77 (1) ◽  
pp. 1-13
Author(s):  
Md. Shamsuzzaman ◽  
Ziad Abdul Awal ◽  
Dip Das
Keyword(s):  
Tensile Strength ◽  
Outer Surface ◽  
Abrasion Resistance ◽  
The Other ◽  
Added Value ◽  
Laser Exposure ◽  
Fabric Weight ◽  
Time Required ◽  
Fabric Surface ◽  
Tear Resistance

This paper investigates the changes in the properties of denim garments with respect to laser intensities of different DPI and Pixel Time. The laser added value to denim garments can fade the outer surface and the yarn portion significantly. In this research, DPI 20 and 25 along with Pixel Time 100, 150 and 200 were applied on samples to investigate the fabric weight, absorbency, crease recovery, tear resistance, tensile strength, pilling and abrasion resistance. For each of the cases, increased DPI and Pixel Time had much greater impact than other parameters on the denim garment samples. After treatment, the fabric sample indicated around 10-30% in weight reduction. The absorbency property of the sample on the other hand showed that higher DPI and Pixel Time required less time to absorb the water on the fabric surface. Furthermore, fabric crease recovery property reduced sharply where maximum 33% crease could not recover after laser exposure. For both tear resistance and tensile strength, especially warp way direction, property reduced more compared to weft way direction due to higher fading effects. After 12,000 cycles, both pilling and abrasion resistance property demonstrated significant reduction for higher laser intensities.

Effect of Diameter and Surface Area of Carbon Black Particles on Certain Properties of Rubber Compounds

1944 ◽  
Vol 17 (2) ◽  
pp. 451-474
Author(s):  
D. Parkinson
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Carbon Black ◽  
Abrasion Resistance ◽  
Particle Diameter ◽  
Stiffness Modulus ◽  
Carbon Structures ◽  
Rubber Compounds ◽  
Regular Manner ◽  
Tear Resistance

Abstract Carbon blacks can be grouped into different classes according to the way in which their fineness of division relates to different properties in rubber. Within any one class the principal properties vary in a regular manner with particle size. The normal class consists of the furnace carbons, Kosmos (Dixie)-40, Statex, the rubber-grade impingement carbons, and possibly, the color-grade impingement carbons. The subnormal classes consist of thermal carbons and acetylene and lamp blacks. Irrespective of the above classification, the properties which depend more on fineness of division than on other factors are rebound resilience, abrasion resistance, tensile strength and tear resistance. The lower limit of particle diameter for best tensile strength and tear resistance appears to be higher than that for abrasion resistance. B.S.I, hardness and electrical conductivity are properties which depend at least as much on other factors as on particle size. Stiffness (modulus) depends more on other factors than on particle size. Factors modifying the effects of particle size (or specific surface) include the presence of carbon-carbon structures and a reduction in strength of bond in rubber-carbon structures. Carbon black is thought to exist in rubber in four states: agglomerated, flocculated, dispersed, and bonded to the rubber molecules (the reënforcing fraction). Abrasion resistance is regarded as providing the only reliable measure of reënforcement.

Reinforcement of Polymers. I. Tear Resistance of Filled Mixes and Adhesion of Elastomer to Filler as a Function of Duration and Temperature of Elastomer and Filler Contact

1968 ◽  
Vol 41 (3) ◽  
pp. 601-607
Author(s):  
V. G. Raevskii ◽  
S. M. Yagnyatinskaya ◽  
S. N. Episeeva ◽  
S. S. Voyutskii
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Surface Crack ◽  
General Type ◽  
Physicomechanical Properties ◽  
The Other ◽  
Local Defect ◽  
System Components ◽  
Selection Of ◽  
Tear Resistance

Abstract In accordance with the concepts being developed by the authors of the present paper, the influence of fillers on the properties of filled systems is determined by adhesion of the polymer to the filler. There are indications of the significance of this factor in many papers dealing with the study of reinforcement. However, they do not advance adhesion as a basic factor which determines reinforcement. This has become possible after the development of a procedure for the evaluation of adhesion of polymers to powdered fillers. This paper lists experimental data on the correlation between the duration and temperature of contact of the elastomer with filler particles on the tear resistance of filled mixes, on one hand, and the time and temperature dependence of the adhesion of the system components to one another, on the other. The selection of tear resistance as a characteristic of the physicomechanical properties of the system is governed by the fact that failure starts, as a rule, from a random local defect. Most frequently this is a small cut or surface crack. For this reason, the assertion of a number of researchers that the operating properties of products are more fully characterized by tear resistance rather than by tensile strength is fully acceptable. Besides, tearing is the most general type of destruction of materials, inasmuch as it takes place during rupture as well as during wear.

Some Effects of Solid Fillers in Rubbers

1953 ◽  
Vol 26 (1) ◽  
pp. 156-165
Author(s):  
Ira Williams
Keyword(s):  
Tensile Strength ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Abrasion Resistance ◽  
Volume Loading ◽  
Rubber Compounds ◽  
Before And After ◽  
The Matrix ◽  
The Many ◽  
Tear Resistance

Abstract The presence of pigments in rubber compounds produces physical properties which are of importance both before and after vulcanization. The ability of the unvulcanized mixture to calender or extrude smoothly with minimum swelling and to maintain shape during air cures, and the tensile strength, tear resistence, and abrasion resistance of vulcanized stocks all are affected. The methods by which these changes are brought about have been considered by many investigators and have been summarized by Parkinson1 and by Shepard, Street, and Park. Since carbon black is the most generally useful reinforcing pigment, it is natural that investigations have been directed particularly to this product. However, while it is recognized that differences exist in the final properties imparted by different pigments, all solid compounding ingredients have something in common. This point can be illustrated by the tear resistance imparted by such a variety of pigments as carbon black, zinc oxide, whiting, and clay. The effect of volume loading on the tear resistance of vulcanized stocks containing these materials, determined by the method of Zimmerman is shown in Figure 1. The effect of solid compounding ingredients can be studied only by considering the compound as a whole, since the properties are determined very largely by the relation between the solid particle and the matrix which surrounds it. Since the introduction of the many types of synthetic rubbers, the complexity of the problem has been greatly increased by the different states of polymerization, which affect the ability of the rubber to conform to the shape of the pigment particle and by the differences in polar nature which affect the type and the degree of adhesion between filler and matrix.

Blends of Elastomers and Thermoplastics—A Review

1976 ◽  
Vol 49 (4) ◽  
pp. 978-991 ◽  
Author(s):  
J. R. Dunn
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Environmental Stress ◽  
Abrasion Resistance ◽  
Impact Resistance ◽  
The Other ◽  
Tear Strength ◽  
Stress Cracking ◽  
Environmental Stress Cracking ◽  
Thermoplastic Blends

Abstract In blends of elastomers and thermoplastics one component may be regarded as reinforcing the other. Examples are enhancement of tensile strength, tear strength, abrasion resistance, and modulus of elastomers by thermoplastics and improvement of impact resistance and environmental stress-cracking resistance of thermoplastics by elastomers. Certain elastomer-thermoplastic blends are rapidly growing in importance as thermoplastic rubbers because they combine the processing characteristics of plastics with physical properties similar to those of vulcanized elastomers.

The Radiation Curing of Elastomers. I. Physical Strength

1972 ◽  
Vol 45 (1) ◽  
pp. 193-203 ◽  
Author(s):  
D. S. Pearson ◽  
G. G. A. Böhm
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Abrasion Resistance ◽  
Amorphous Polymers ◽  
Strength Properties ◽  
The Other ◽  
Radiation Curing ◽  
Physical Strength ◽  
Crystalline Polymers ◽  
Maximum Tensile Strength

Abstract Data has been presented which shows that sulfur crosslinks have very little importance in producing maximum tensile strength in amorphous polymers. The results suggest that the distribution of crosslinks, especially in the case of crystalline polymers, is. a factor to be considered. In general, radiation cured elastomer compounds have physical strength properties very similar to sulfur or peroxide cured compounds. This similarity has been noted for a wide number of other elastomers not reported here. The observed strength deficiency is minor in degree and of little industrial importance provided the other properties are not too different. These properties such as fatigue life, abrasion resistance, and hysteresis will be discussed in a later publication.

Immunochemical Studies on Antithrombin III

1979 ◽  
Author(s):  
E.J. McKay
Keyword(s):  
Antithrombin Iii ◽  
The Other ◽  
Antigenic Determinants ◽  
Immunochemical Analysis ◽  
Paradoxical Effect ◽  
Test Protocol ◽  
Agar Gel ◽  
High Affinity ◽  
Time Required ◽  
Antigen Antibody

Depressed Antithrombin III (AT) levels Increase thrombic tendency in man, therefore value in assaying this protein has been established. Immunochemical analysis of AT in clinical disease has however proved controversial, consequently systematic studies were undertaken to rationalize the requirements necessary to optimise these methods in particular electro-Immunoassay. The known binding affinity of AT for heparin has been exploited to differentiate high affinity AT from its inhibitor - protease complexes and has resulted in reports stating that heparin added to the agar gel prior to electrophoresis significantly reduces the time required for completion of antigen/antibody complexes. Our studies however have demonstrated that the antibody required for quantitative analysis must be capable of not only reacting with “native” antigenic determinants of AT but also with “neo” antigens that are exposed when inhibitor-protease complexes are formed. Heparin should not be used in the test protocol, for it has a paradoxical effect on Immunopreclpltation in gels, masking some antigenic determinants of unbound - high affinity AT on one hand, and appear to disrupt the Immunoprecipitin “rocket” formed with the inhibitor-protease complexes during electrophoresis on the other.

scholarly journals Effects of water absorption on the mechanical properties of hybrid natural fibre/phenol formaldehyde composites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sekar Sanjeevi ◽  
Vigneshwaran Shanmugam ◽  
Suresh Kumar ◽  
Velmurugan Ganesan ◽  
Gabriel Sas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Water Absorption ◽  
Hybrid Composites ◽  
Phenol Formaldehyde ◽  
Natural Fibre ◽  
The Other ◽  
Fibre Reinforcement ◽  
Dry Conditions

AbstractThis investigation is carried out to understand the effects of water absorption on the mechanical properties of hybrid phenol formaldehyde (PF) composite fabricated with Areca Fine Fibres (AFFs) and Calotropis Gigantea Fibre (CGF). Hybrid CGF/AFF/PF composites were manufactured using the hand layup technique at varying weight percentages of fibre reinforcement (25, 35 and 45%). Hybrid composite having 35 wt.% showed better mechanical properties (tensile strength ca. 59 MPa, flexural strength ca. 73 MPa and impact strength 1.43 kJ/m2) under wet and dry conditions as compared to the other hybrid composites. In general, the inclusion of the fibres enhanced the mechanical properties of neat PF. Increase in the fibre content increased the water absorption, however, after 120 h of immersion, all the composites attained an equilibrium state.

Long Time Coming: Prospects for Democracy in Iraq

2009 ◽  
Vol 33 (4) ◽  
pp. 115-148 ◽  
Author(s):  
Bruce E. Moon
Keyword(s):  
Nineteenth Century ◽  
The Other ◽  
Democratic Transitions ◽  
Quarter Century ◽  
The Past ◽  
Political Experience ◽  
Long Time ◽  
Time Required ◽  
Established Democracies

Prospects for democracy in Iraq should be assessed in light of the historical precedents of nations with comparable political experiences. Saddam Hussein's Iraq was an unusually extreme autocracy, which lasted an unusually long time. Since the end of the nineteenth century, only thirty nations have experienced an autocracy as extreme as Iraq's for a period exceeding two decades. The subsequent political experience of those nations offers a pessimistic forecast for Iraq and similar nations. Only seven of the thirty are now democratic, and only two of them have become established democracies; the democratic experiments in the other five are still in progress. Among the seven, the average time required to transit the path from extreme autocracy to coherent, albeit precarious, democracy has been fifty years, and only two have managed this transition in fewer than twenty-five years. Even this sober assessment is probably too optimistic, because Iraq lacks the structural conditions that theory and evidence indicate have been necessary for successful democratic transitions in the past. Thus, the odds of Iraq achieving democracy in the next quarter century are close to zero, at best about two in thirty, but probably far less.

scholarly journals Increased take-off level in automatic milking systems – effects on milk flow, milk yield and milking efficiency at the quarter level

2018 ◽  
Vol 86 (1) ◽  
pp. 85-87 ◽  
Author(s):  
Sabine Ferneborg ◽  
Måns Thulin ◽  
Sigrid Agenäs ◽  
Kerstin Svennersten-Sjaunja ◽  
Peter Krawczel ◽  
...  
Keyword(s):  
Flow Rate ◽  
The Other ◽  
Mean Flow ◽  
Flow Rates ◽  
Decline Phase ◽  
Flow Profiles ◽  
Milk Flow ◽  
Automatic Milking ◽  
Automatic Milking Systems ◽  
Time Required

AbstractThis research communication describes how different detachment levels (0.48, 0.3 and 0.06 kg milk/min) at the quarter-level affect milk flow profiles and overall milking efficiency in automatic milking systems. We hypothesized a higher detachment level would result in greater mean flow rates without affecting the volume of harvested milk per cow during 24 h compared to lower detachment levels. The data suggest milk flow decreased to a rate below the overmilking limit within the 6-s delay time required for termination in all treatments, but the duration of overmilking was shorter for the greatest detachment level compared to the other treatments. We conclude that setting a detachment level at a greater milk flow rate reduces the duration of overmilking without affecting the amount of milk harvested when applied to cows in mid-lactation during quarter-level milking. We also suggest that the steepness of the decline phase of the milk flow curve might have a larger effect than the actual detachment level on the duration of overmilking.

scholarly journals The effect of a lack of uncapped brood on social interactions between honey bee workers and the queen

Apidologie ◽  
2021 ◽  
Author(s):  
Sylwia Łopuch ◽  
Adam Tofilski
Keyword(s):  
Social Interactions ◽  
Honey Bee ◽  
Honey Bees ◽  
High Speed ◽  
Egg Production ◽  
Social Contexts ◽  
The Other ◽  
High Speed Camera ◽  
Time Required ◽  
Honey Bee Workers

AbstractVibro-acoustic communication is used by honey bees in many different social contexts. Our previous research showed that workers interact with their queen outside of the swarming period by means of wing-beating behaviour. Therefore, the aim of this study was to verify the hypothesis that the wing-beating behaviour of workers attending the queen stimulates her to lay eggs. The behaviour of workers and the queen was recorded using a high-speed camera, at first in the presence of uncapped brood in the nest and then without one. None of the queens performed wing-beating behaviour. On the other hand, the workers attending the queen demonstrated this behaviour two times per minute, on average, even in the presence of uncapped brood in the nest. After removing the combs with the uncapped brood, the incidence of wing-beating behaviour increased significantly to an average of four times per minute. Wing-beating behaviour did not differ significantly in its characteristics when uncapped brood was present or absent in the nest. During 3 days after removing the combs with the uncapped brood, there was no significant increase in the rate of egg lying by the queen. Therefore, the results presented here do not convincingly confirm that the wing-beating behaviour of workers affects the rate of queen's egg-lying. This negative result can be related to colony disturbance and longer time required by the queen to increase egg production.

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