Rubber Stocks for Improved Performance of Polyester Cord Tires

1973 ◽  
Vol 46 (2) ◽  
pp. 442-448 ◽  
Author(s):  
Y. Iyengae ◽  
D. F. Ryder
Keyword(s):  
Laboratory Tests ◽  
Extended Period ◽  
Extreme Conditions ◽  
Endurance Test ◽  
Good Adhesion ◽  
Carboxyl Content ◽  
Amine Content ◽  
Improved Performance ◽  
Polyester Cord ◽  
Butadiene Styrene

Abstract Carcass stocks were developed with acceptable properties and good adhesion to polyester tire cords after severe heat aging in laboratory tests. These stocks contained vulcanization accelerators that did not liberate amines and were based either on synthetic poly (isoprene) (IR)/butadiene/styrene (SBR) elastomer blends, as recommended in previous work, or natural rubber/SBR compounds containing an additive to inhibit the deleterious effects of amines present as impurities in NR. Standard SBR/poly (butadiene) (BR) tread stocks containing amine-free accelerators were developed to match the exceptionally long scorch time and good physical properties attained with sulfenamide accelerators normally used in such stocks. Large batches (˜400 pounds) of amine-free tread stock were processed without any scorch problems on a commercial Banbury mixer and tread extruder. With these tread stocks, containing amine-free accelerators, it is possible to build completely amine-free polyester cord tires. In a variety of wheel tests designed to assess durability under extreme conditions, 2-ply tires with cords of Dacron polyester containing amine-free tread and carcass stocks showed highly improved durability (180-440 per cent) compared to control tires made with stocks containing amines. In a wheel test simulating the running of a tire underinflated for an extended period (low pressure endurance test), tire durability increased with decreasing amine content of the rubber stocks used. In a special high temperature tire fatigue test to produce break-above-bead failures, tires combining an experimental Dacron polyester with low carboxyl content and in amine-free stocks ran 350 per cent longer than tires of standard T-68 Dacron in amine containing stocks. These tests clearly illustrated the additive benefits of combining an improved polyester with stocks having reduced amine content.

ONR REVIEW: ARCHITECTED COMPOSITES FOR DAMAGE TOLERANCE IN EXTREME CONDITIONS

2021 ◽  
Author(s):  
PAVANA PRABHAKAR ◽  
VINAY DAMODARAN, ◽  
ABARINATHAN PUSHPARAJ SUBRAMANIYAN
Keyword(s):  
Energy Dissipation ◽  
Composite Structures ◽  
Computational Models ◽  
Peak Load ◽  
Moisture Diffusion ◽  
Honeycomb Structure ◽  
Sandwich Composite ◽  
Extreme Conditions ◽  
Improved Performance ◽  
Damage Tolerant

The long-term goal of this ONR funded project is to facilitate the design of architected composites that play a key role in damage tolerant and resilient structures. The main emphasis is on developing new composite structures with improved performance and durability as compared to conventional structural composites. To that end, we will present our work in detail on the following within the realm of sandwich composites along with a novel Machine Learning framework for stress prediction in composites: 1) Novel recoverable sandwich composite structures: Traditional sandwich cores such as foam core or honeycomb structures are good options for enabling lightweight and stiff structures. Although, these cores are known to dissipate energy under extreme conditions such as impact loading, they experience permanent damage. Here, our goal is to design core structures that undergo substantial deformation without accumulating damage and recover their original geometric configuration after the loading is removed. In contrast to a traditional foam or honeycomb structure, we have developed a multi-layer architected core design that facilitates significant deformation beyond the initial peak load, yielding a larger energy dissipation during impact and other extreme loading scenarios. We utilize the concept of pseudo-bistability of truncated cone unit cells to achieve elastic buckling for energy dissipation and shape recovery of core structures. 2) Tailoring of sandwich composite facings: Our objective is to establish the influence of fiber architecture on moisture diffusion pathways in FRPC facings for enabling damage tolerant facing designs. To that end, we have evaluated the moisture kinetics in FRPCs by developing micromechanics based computational models within FEM. We have explained the effect of tortuous diffusion pathways that manifest within FRPCs due to internal fiber architectures. Finally, we established the relationship between tortuosity and diffusivity that can be used for studying moisture diffusion in other FRPCs.

Correlation of Reduced Endurance Capacity of Neck Flexor and Extensor in Cigarette Smokers of College Going Students

2021 ◽  
Vol 11 (7) ◽  
pp. 25-30
Author(s):  
Manasi Rajesh Zele ◽  
Sneha Katke ◽  
Manal Anthikat
Keyword(s):  
Statistical Significance ◽  
Extended Period ◽  
Load Resistance ◽  
Smoking History ◽  
Endurance Capacity ◽  
Endurance Test ◽  
Skeletal Muscle Dysfunction ◽  
College Going ◽  
Extensor Muscles ◽  
College Of Nursing

Background: Muscle endurance is the ability of muscle to contract repeatedly against a load (resistance), generated and sustain tension and resist fatigue over an extended period of time. Smoking causes variety of health diseases and it also affects skeletal muscle dysfunction as well. Cigarette smoke constituents and systemic inflammatory mediators enhance proteolysis and inhibit protein synthesis, leading to loss of muscle mass. Objectives: To find out the correlation between the neck flexor endurance capacity and neck extensor endurance capacity with 1-5 years of smoking history. Methods: Data collection was done from college of physiotherapy and college of nursing using convenient sampling. 60 Male subjects were included in study between the age group of 20-30 years with 1-5 years of smoking history. The score of neck flexor endurance capacity and neck extensor endurance capacity using neck flexor endurance test and neck extensor endurance test, and the data were analyzed. Result: The result of study showed a statistical significance in the neck flexor and extensor endurance capacity (p=<0.001) (r=-0.59 for NFEC, -0.54 for NEEC) using neck flexor endurance capacity test and neck extensor endurance capacity test in subjects with 1-5 years of smoking history. Conclusion: The study concludes that there is reduced endurance capacity of neck flexor and neck extensor muscles in smokers with 1-5 years of smoking history. Key words: Cigarette smoking, muscle strength, neck flexor and extensor endurance test, 1-5 years smoking history.

Long-term cannulation model for blood sampling and intragastric infusion in the rat

1984 ◽  
Vol 247 (3) ◽  
pp. R595-R599 ◽  
Author(s):  
H. Tsukamoto ◽  
R. D. Reidelberger ◽  
S. W. French ◽  
C. Largman
Keyword(s):  
Weight Gain ◽  
Laboratory Tests ◽  
Clinical Laboratory ◽  
Extended Period ◽  
Plasma Corticosterone ◽  
Blood Sampling ◽  
Success Rates ◽  
The Third ◽  
Minimal Stress

An improved methodology is described for long-term venous and gastric cannulation in the rat. The long-term efficacy of the cannulas for blood sampling and intragastric infusion of liquid diet was determined in 18 rats. No animals died after surgery, and weight gain was normal. During the first 6 wk, blood could be drawn repetitively in 94% of the rats, and continuous intragastric infusion of diet was maintained in all the animals. For an extended period of 11 wk, success rates for blood sampling and dietary infusion were 75 and 100%, respectively. Standard hematological, histopathological, and clinical laboratory tests showed no abnormal changes. Furthermore, plasma corticosterone levels were consistently low (0.5 +/- 0.11 to 1.52 +/- 0.55 micrograms/dl) from the third postoperative day throughout a period of 6 wk, indicating that animals were under minimal stress.

Optimization of content of a new modifier type in bitumen intended for waterproofing products

2016 ◽  
Vol 43 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Krzysztof Zieliński ◽  
Michał Babiak
Keyword(s):  
Laboratory Tests ◽  
Considerable Improvement ◽  
New Materials ◽  
Modify Bitumen ◽  
Before And After ◽  
New Type ◽  
Styrene Butadiene Styrene ◽  
New Generation ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Styrene-butadiene-styrene (SBS) is currently the most popular bitumen modifier. Its weaknesses have become a strong incentive to search for new materials that could modify bitumen in a similar scope as SBS, but would be cheaper and easier to use. The article presents the results of studies of oleic imidazoline — a new generation bitumen modifier. The analysis of the results of laboratory tests allowed for the optimization of its content in bitumen. It has been demonstrated that the new type modifier developed by the authors of the article has a significant impact on physical characteristics of bitumen. Its use results in a significant increase of bitumen plasticity range, both before and after laboratory ageing, and a considerable improvement of bitumen resistance to ageing.

scholarly journals OBTAINING FILLED POLYURETHANE FOAM WITH IMPROVED OPERATIONAL PROPERTIES

2019 ◽  
Vol 4 (4) ◽  
pp. 47-52
Author(s):  
А. Кочерженко ◽  
A. Kocherzhenko
Keyword(s):  
Polyurethane Foam ◽  
Raw Materials ◽  
Fusion Reaction ◽  
Mining Industry ◽  
Polyurethane Foams ◽  
Insulation Material ◽  
Good Adhesion ◽  
Foaming Process ◽  
Improved Performance ◽  
Selection Of

One of the most important advantages of polyurethane foam is the ability of single-stage production. Foaming and curing of this heat insulation does not require the supply of heat in connection with the exothermic fusion reaction that occurs when two or more liquid components are mixed, with simultaneous adhering of polyurethane foam to various surfaces due to good adhesion to almost any material. At the same time, this foam polymer has a low density and is able to withstand quite large loads. Thermal insulation material with improved performance properties can be obtained with a careful selection of the granulometric and chemical composition of raw materials. This paper presents a brief overview of the foaming and shaping of polyurethane, examines the structure of developed composite insulation, and establishes the dependence of the foaming ratio of polyurethane foam on the granulometric composition of fillers, including man-made (waste mining industry Stoylensky GOK). The research results show that in the process of forming filled polyurethane foams, chemical reactions between the components of the polyurethane foam and the elements of the fillers do not occur. The foaming process depends mainly on the granulometry of the filler and its percentage in the total mass of polyurethane foam.

scholarly journals Mechanical Behavior of Triaxial Geogrid Used for Reinforced Soil Structures

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jun Zhang ◽  
Wen-Zhao Cao ◽  
Yan-Jun Zhou
Keyword(s):  
Tensile Strength ◽  
Mechanical Behavior ◽  
Laboratory Tests ◽  
Reinforced Soil ◽  
Geological Hazards ◽  
Grid Structure ◽  
Interface Friction ◽  
Pullout Tests ◽  
Soil Structures ◽  
Improved Performance

Geosynthetics-reinforced soil (GRS) structures have been widely used for the prevention of geological hazards. As a recently introduced product, the triaxial geogrid has been confirmed to provide improved performance due to the more stable grid structure. This paper presents an evaluation of the mechanical behavior based on a series of laboratory tests. The unconfined tensile strength of biaxial geogrid and triaxial geogrid in different loading directions relative to the orientation of ribs was investigated. Then, more than 8 pullout tests were conducted on the triaxial geogrid specimens embedded in the compacted sand. The internal displacements along the geogrid length were monitored. The results show that the triaxial geogrid has been shown to provide nearly uniform tensile strength in all loading directions as compared with the biaxial geogrid. The triaxial geogrid deformation is mainly characterized by rib bending and nodal distortion along with an inward squeeze perpendicular to the pullout direction. The interface friction between the soil and the geogrid develops in a progressive mode, and an elasto-plastic-softening characteristic is detected experimentally due to the extensibility of geogrid.

scholarly journals Enhanced Performance of PVDF Composite Ultrafiltration Membrane via Degradation of Collagen-Modified Graphene Oxide

2021 ◽  
Vol 11 (23) ◽  
pp. 11513
Author(s):  
Yonggang Hou ◽  
Shenghua Lv ◽  
Haoyan Hu ◽  
Xinming Wu ◽  
Leipeng Liu
Keyword(s):  
Graphene Oxide ◽  
Polyvinylidene Fluoride ◽  
Membrane Surface ◽  
Water Flux ◽  
Ultrafiltration Membrane ◽  
Carboxyl Content ◽  
Modified Graphene Oxide ◽  
Leather Waste ◽  
Improved Performance ◽  
Modified Graphene

The collagen obtained from chrome leather waste can be used to modify graphene oxide (GO) to prepare polyvinylidene fluoride (PVDF) composite ultrafiltration membranes, a process that is conducive to the recovery of leather waste, comprehensive utilization of GO and improved performance of the membrane. In this paper, collagen-modified GO (CGO) was prepared by degradation of collagen from chrome leather waste and used to prepare a PVDF composite ultrafiltration membrane. The results show that the carboxyl content of CGO and dispersion were improved. The water flux and flux recovery rate of the modified ultrafiltration membrane were improved. The bovine serum albumin (BSA) intercepted on the membrane surface was easy to clean and the antifouling performance improved. The performance of the membrane decreased when the GO content exceeded 0.75 wt%, while CGO can reach 1.0 wt% without agglomeration due to its good dispersion.

Smartphone Enabled Phototherapy Irradiance Meter for the Care of the Jaundiced Neonates in Low-Resource Regions

2020 ◽  
Author(s):  
Patrick Powell ◽  
Isa Abdulkadir ◽  
Tina M. Slusher ◽  
Katie Satrom ◽  
Gary DeWitt
Keyword(s):  
Clinical Training ◽  
Laboratory Tests ◽  
Field Testing ◽  
Clinical Environment ◽  
Low Resource ◽  
Remote Sensor ◽  
Feature Based ◽  
Improved Performance ◽  
Expected Benefits ◽  
Mobile Smartphone

Abstract Smartphones have become near ubiquitous on the global stage placing the power of both computational analytics and communication into the hands of users in both high and low-resource regions alike. The potential to leverage these devices to address inequities in healthcare are enormous. Our development team theorizes that we can create a medical device blending a traditional pediatric phototherapy irradiance meter for the treatment of neonatal jaundice with a mobile smartphone to create a reasonably priced irradiance meter with improved performance specifically for low-resource regions. The result of our work is a minimum viable prototype based on an Android operating system tethered wirelessly to a remote sensor that incorporates a clinical training feature. Based on laboratory tests simulating a clinical environment and field testing in Northern Nigeria, the results were equivalent to standard phototherapy meters with additional expected benefits of cost, mobility, access and clinical training.

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