HYSTERESIS CHARACTERISTICS OF HIGH MODULUS LOW SHRINKAGE POLYESTER TIRE YARN AND CORD

2011 ◽  
Vol 84 (4) ◽  
pp. 565-579 ◽  
Author(s):  
Barun Kumar Samui ◽  
Manikanda Priya Prakasan ◽  
D. Chakrabarty ◽  
R. Mukhopadhyay
Keyword(s):  
Dynamic Property ◽  
High Speed ◽  
Dynamic Test ◽  
Specific Work ◽  
High Modulus ◽  
Work Loss ◽  
Speed Test ◽  
Wide Range ◽  
Tan Δ ◽  
Hysteresis Characteristics

Abstract Hysteresis characteristics of high modulus low shrinkage (HMLS) polyester tire yarn and cord were evaluated to determine “specific work loss,” which indicate its heat generation characteristics. Test parameters were selectively chosen, considering the service conditions of high-speed passenger radial tires in which HMLS polyester tire cords are predominantly used. Specific work loss was found to increase exponentially with the increase in extent of stress relief. Dynamic property of this yarn and cord was also studied to determine “loss tangent (tan δ),” which influences rolling resistance of tires in service. A good correlation has been found between specific work loss of hysteresis test (a slow speed test) and tan δ of dynamic test (a high-speed test). Dynamic property of polyester dipped cord was investigated for a wide range of temperatures (100–180 °C) and frequencies (5–25 Hz). Tan δ at 100 °C was found to be relatively low and its magnitude remained at the same level for a wide range of frequencies. This is a favorable condition for the high-speed passenger radial tires, made out of HMLS polyester tire yarn. Microstructure of HMLS polyester yarn was analyzed. Crystallinity is around 43% (measured by Wide angle x-ray scattering); crystal width and long period are 61 and 142 Å, respectively.

Measurement of Wet cornering Traction of Tires

1971 ◽  
Vol 44 (4) ◽  
pp. 962-995 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Boundary Layer ◽  
High Speed ◽  
Elastohydrodynamic Lubrication ◽  
Speed Test ◽  
High Speeds ◽  
Wide Range ◽  
Low Speeds ◽  
Test Variability ◽  
Traction Testing ◽  
Tread Rubber

Abstract We have shown that the cornering wet traction performance of tires, as measured with a special cornering trailer, is influenced by a number of factors and their interaction with each other. Unlike conventional low speed “spin-out” wet cornering traction testing, we have evaluated tire traction over the range 30–60 mph. Over this range there is a marked speed dependence in the rating of various tread rubbers and tread patterns. In general, tread rubbers show a wide range of performance ratings at the lower speeds (30–35 mph) and a narrower range at high speeds (55–60 mph). Various tread patterns on the contrary show similar behavior at low speeds but a wide divergence in traction level at high speeds. Higher durometer tread compounds show improved high speed traction for any given rubber. Tread hardness cannot be used as an omnibus indicator of wet traction performance, however, as each rubber has its own separate correlation line. Low coefficient pavement can have either low or high degrees of macrotexture, but the lack of microtexture or harshness (asperities in the fraction of a millimeter range) produces this type of pavement. Tires must perform safely on such pavement sections of public highways and the testing reported here was done on such test surfaces. Evaluations of four types of tread rubber show that they rank from high to low traction level in the order: SBR, Butyl, NR and BR (solution type) on smooth, low microtexture surfaces. Although BR gives low traction when used alone it is not so used in commercial tread compounds. When properly blended with SBR or NR, tread compounds containing BR give satisfactory traction performance and improved wear performance. The overall behavior of tires can be explained in terms of the concepts of hydrodynamic and boundary layer lubrication. At low speeds boundary layer lubrication predominates on all but the smoothest pavements. This accounts for the marked influence of tread rubber at low speeds. At high speeds both thick and thin film elastohydrodynamic lubrication predominate. In this speed range tread materials play a lesser role and tread pattern or geometry plays a larger role. The relative softness and deformability of tread compound, compared to pavement aggregate, accounts for the importance of elastohydrodynamic lubrication. Drawing on the work of many previous investigators and the data of this work it is postulated that the fraction of the tire contact area of a cornering tire that is in the elastohydrodynamic mode of lubrication is a linear function of speed. This accounts for the good linearity of the plots of traction as a function of speed. Test variability is discussed and steps taken to measure and control such relevant factors as water depth are outlined. The use of statistically designed testing programs with their inherent averaging character are advocated for those doing this work. In addition to their power at averaging test results, such designs uncover the strong interaction between tire and test variables that underlie all wet traction testing.

The Effects of Carbon Black and Other Compounding Variables on Tire Rolling Resistance and Traction

1983 ◽  
Vol 56 (2) ◽  
pp. 390-417 ◽  
Author(s):  
W. M. Hess ◽  
W. K. Klamp
Keyword(s):  
Carbon Black ◽  
High Speed ◽  
Dynamic Testing ◽  
Aggregate Size ◽  
Rolling Resistance ◽  
High Viscosity ◽  
High Positive Correlation ◽  
Wide Range ◽  
Tan Δ ◽  
High Viscosity Oil

Abstract The rolling resistance of SBR/BR radial passenger tire treads was varied as a function of carbon black type and loading, as well as other compounding variables, such as oil content, high-viscosity oil and resin addition, and NR substitution. In all instances, the rolling loss variations showed a good correlation with either tan δ or resilience. The tan δ response was valid for a wide range of test temperatures, frequencies, and strain amplitudes. Wet (32 km/h) and dry (64 km/h) traction indicated a high positive correlation with loss compliance (D″). Here, the best correlations were obtained at lower dynamic testing temperatures (0–25°C.) and higher strain amplitudes. High-speed wet traction (97 km/h) appeared to be relatively independent of the tread compounding variables but did show a slight correlation with tan δ measured at ™25°C. The following patterns were observed relative to tread rolling resistance, traction, and wear as a function of compounding variables: 1. Black loading.—Reduced black loading lowers rolling resistance without much effect on traction. About 4% less black in the tread compound lowers rolling resistance by about 5–6% in the formulations which were evaluated. 2. Oil loading.—At a fixed black level, increased oil raises both rolling resistance and traction. About 2% higher rolling resistance was found for a 10 phr increase in oil loading, but the effect on wet traction appeared to be much greater (7–8%). 3. Black type.—Increasing black fineness raises both rolling resistance and traction, the latter effect being considerably less. Increased DBPA has very little effect on rolling resistance but reduces traction. At reduced black loadings, the finer and higher DBPA blacks show the least loss in treadwear resistance. Blacks with broad aggregate size distribution give lower rolling resistance at the same surface area and DBPA. For extreme blends (carcass and tread grades), however, the loss in treadwear resistance is quite severe (∼30%). 4. Curatives.—Increased sulfur and accelerator levels produced a significant reduction in tan δ, with a similar but lesser drop in D″. The same reduction in tan δ with increased accelerator (OBTS) level produced less effect on D″ than the sulfur increase. 5. Natural rubber substitution.—Compounds in which 30 phr of NR were substituted for 25 phr of SBR and 5 phr of BR indicated slightly better performance in terms of both rolling resistance and traction. 6. High-viscosity oil or resin substitution.—Replacing conventional extender oil with high-viscosity oil or resin appears to improve traction but has a greater adverse effect on rolling resistance. 7. Compound optimization.—N299 black gives the best overall balance of performance in terms of rolling resistance, traction, and treadwear at reduced black loadings. N121 confers about 10% better treadwear and equal traction in the same compound, but at about 4% higher rolling resistance.

Dynamic Property of Load Cell Transducers in High Speed Test of Soil.

1997 ◽  
pp. 123-130
Author(s):  
Hiroshi Kondo ◽  
Kouichi Iinuma ◽  
Takeshi Uramaru ◽  
Jun Sawada
Keyword(s):  
Dynamic Property ◽  
High Speed ◽  
Load Cell ◽  
Speed Test

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Assessment of Commercial Off-the-Shelf Tissue Adhesives for Sealing Military-Relevant Corneal Perforation Injuries

2021 ◽  
Author(s):  
Eric J Snider ◽  
Lauren E Cornell ◽  
Brandon M Gross ◽  
David O Zamora ◽  
Emily N Boice
Keyword(s):  
Intraocular Pressure ◽  
High Speed ◽  
Anterior Segment ◽  
Ocular Tissue ◽  
Corneal Tissue ◽  
Corneal Perforation ◽  
Tissue Adhesives ◽  
Open Globe ◽  
Wide Range ◽  
Commercial Off The Shelf

ABSTRACT Introduction Open-globe ocular injuries have increased in frequency in recent combat operations due to increased use of explosive weaponry. Unfortunately, open-globe injuries have one of the worst visual outcomes for the injured warfighter, often resulting in permanent loss of vision. To improve visual recovery, injuries need to be stabilized quickly following trauma, in order to restore intraocular pressure and create a watertight seal. Here, we assess four off-the-shelf (OTS), commercially available tissue adhesives for their ability to seal military-relevant corneal perforation injuries (CPIs). Materials and Methods Adhesives were assessed using an anterior segment inflation platform and a previously developed high-speed benchtop corneal puncture model, to create injuries in porcine eyes. After injury, adhesives were applied and injury stabilization was assessed by measuring outflow rate, ocular compliance, and burst pressure, followed by histological analysis. Results Tegaderm dressings and Dermabond skin adhesive most successfully sealed injuries in preliminary testing. Across a range of injury sizes and shapes, Tegaderm performed well in smaller injury sizes, less than 2 mm in diameter, but inadequately sealed large or complex injuries. Dermabond created a watertight seal capable of maintaining ocular tissue at physiological intraocular pressure for almost all injury shapes and sizes. However, application of the adhesive was inconsistent. Histologically, after removal of the Dermabond skin adhesive, the corneal epithelium was removed and oftentimes the epithelium surface penetrated into the wound and was adhered to inner stromal tissue. Conclusions Dermabond can stabilize a wide range of CPIs; however, application is variable, which may adversely impact the corneal tissue. Without addressing these limitations, no OTS adhesive tested herein can be directly translated to CPIs. This highlights the need for development of a biomaterial product to stabilize these injuries without causing ocular damage upon removal, thus improving the poor vision prognosis for the injured warfighter.

scholarly journals Vibration of Rotating and Revolving Planet Rings with Discrete and Partially Distributed Stiffnesses

2020 ◽  
Vol 11 (1) ◽  
pp. 127
Author(s):  
Fuchun Yang ◽  
Dianrui Wang
Keyword(s):  
High Speed ◽  
Differential Operators ◽  
Natural Frequencies ◽  
Rotation Speed ◽  
Distribution Area ◽  
Vibration Modes ◽  
Governing Equations ◽  
Vibration Properties ◽  
Wide Range ◽  
Forced Responses

Vibration properties of high-speed rotating and revolving planet rings with discrete and partially distributed stiffnesses were studied. The governing equations were obtained by Hamilton’s principle based on a rotating frame on the ring. The governing equations were cast in matrix differential operators and discretized, using Galerkin’s method. The eigenvalue problem was dealt with state space matrix, and the natural frequencies and vibration modes were computed in a wide range of rotation speed. The properties of natural frequencies and vibration modes with rotation speed were studied for free planet rings and planet rings with discrete and partially distributed stiffnesses. The influences of several parameters on the vibration properties of planet rings were also investigated. Finally, the forced responses of planet rings resulted from the excitation of rotating and revolving movement were studied. The results show that the revolving movement not only affects the free vibration of planet rings but results in excitation to the rings. Partially distributed stiffness changes the vibration modes heavily compared to the free planet ring. Each vibration mode comprises several nodal diameter components instead of a single component for a free planet ring. The distribution area and the number of partially distributed stiffnesses mainly affect the high-order frequencies. The forced responses caused by revolving movement are nonlinear and vary with a quasi-period of rotating speed, and the responses in the regions supported by partially distributed stiffnesses are suppressed.

scholarly journals Towards a Glass New World: The Role of Ion-Exchange in Modern Technology

2021 ◽  
Vol 11 (10) ◽  
pp. 4610
Author(s):  
Simone Berneschi ◽  
Giancarlo C. Righini ◽  
Stefano Pelli
Keyword(s):  
Ion Exchange ◽  
Communication Networks ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Modern Technology ◽  
Historical Background ◽  
Wide Range ◽  
Happy Marriage

Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.

scholarly journals Prototype Design and Experimental Evaluation of Autonomous Collaborative Communication System for Emerging Maritime Use Cases

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3871
Author(s):  
Jiri Pokorny ◽  
Khanh Ma ◽  
Salwa Saafi ◽  
Jakub Frolka ◽  
Jose Villa ◽  
...  
Keyword(s):  
Communication System ◽  
Autonomous Vehicles ◽  
High Speed ◽  
High Capacity ◽  
Workplace Safety ◽  
Unmanned Vehicles ◽  
Use Cases ◽  
Automated Systems ◽  
Collaborative Communication ◽  
Wide Range

Automated systems have been seamlessly integrated into several industries as part of their industrial automation processes. Employing automated systems, such as autonomous vehicles, allows industries to increase productivity, benefit from a wide range of technologies and capabilities, and improve workplace safety. So far, most of the existing systems consider utilizing one type of autonomous vehicle. In this work, we propose a collaboration of different types of unmanned vehicles in maritime offshore scenarios. Providing high capacity, extended coverage, and better quality of services, autonomous collaborative systems can enable emerging maritime use cases, such as remote monitoring and navigation assistance. Motivated by these potential benefits, we propose the deployment of an Unmanned Surface Vehicle (USV) and an Unmanned Aerial Vehicle (UAV) in an autonomous collaborative communication system. Specifically, we design high-speed, directional communication links between a terrestrial control station and the two unmanned vehicles. Using measurement and simulation results, we evaluate the performance of the designed links in different communication scenarios and we show the benefits of employing multiple autonomous vehicles in the proposed communication system.

scholarly journals Jet-Surface Interaction Test: Far-Field Noise Results

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Clifford A. Brown
Keyword(s):  
High Speed ◽  
Radial Distance ◽  
Jet Noise ◽  
Surface Interaction ◽  
Shielding Effect ◽  
Noise Prediction ◽  
Far Field ◽  
Wide Range ◽  
Field Noise ◽  
Surface Length

Many configurations proposed for the next generation of aircraft rely on the wing or other aircraft surfaces to shield the engine noise from the observers on the ground. However, the ability to predict the shielding effect and any new noise sources that arise from the high-speed jet flow interacting with a hard surface is currently limited. Furthermore, quality experimental data from jets with surfaces nearby suitable for developing and validating noise prediction methods are usually tied to a particular vehicle concept and, therefore, very complicated. The Jet-Surface Interaction Tests are intended to supply a high quality set of data covering a wide range of surface geometries and positions and jet flows to researchers developing aircraft noise prediction tools. The initial goal is to measure the noise of a jet near a simple planar surface while varying the surface length and location in order to: (1) validate noise prediction schemes when the surface is acting only as a jet noise shield and when the jet-surface interaction is creating additional noise, and (2) determine regions of interest for future, more detailed, tests. To meet these objectives, a flat plate was mounted on a two-axis traverse in two distinct configurations: (1) as a shield between the jet and the observer and (2) as a reflecting surface on the opposite side of the jet from the observer. The surface length was varied between 2 and 20 jet diameters downstream of the nozzle exit. Similarly, the radial distance from the jet centerline to the surface face was varied between 1 and 16 jet diameters. Far-field and phased array noise data were acquired at each combination of surface length and radial location using two nozzles operating at jet exit conditions across several flow regimes: subsonic cold, subsonic hot, underexpanded, ideally expanded, and overexpanded supersonic. The far-field noise results, discussed here, show where the jet noise is partially shielded by the surface and where jet-surface interaction noise dominates the low frequency spectrum as a surface extends downstream and approaches the jet plume.

Cost of Speed: Analysis of Capital Cost Estimates for High-Speed Ground Transportation Systems

1997 ◽  
Vol 1584 (1) ◽  
pp. 17-21
Author(s):  
John A. Harrison
Keyword(s):  
Los Angeles ◽  
High Speed ◽  
Capital Cost ◽  
Travel Times ◽  
Department Of Transportation ◽  
High Speed Rail ◽  
Cost Estimates ◽  
Capital Costs ◽  
Trip Time ◽  
Wide Range

The Intermodal Surface Transportation Efficiency Act of 1991 required the U.S. Department of Transportation to evaluate the commercial feasibility of high-speed ground transportation—a family of technologies ranging from incremental rail improvements to high-speed rail and magnetic levitation (Maglev) systems—in selected urban corridors. The evaluation involved estimating travel times, capital costs, operation and maintenance costs, and ridership for proposed service frequencies and then computing the potential return on investment from fares and other potential revenues. The results are documented in a U.S. Department of Transportation report generally referred to as the commercial feasibility study (CFS). Two elements of the CFS are addressed here: travel times and capital costs in four illustrative corridors—Chicago to St. Louis; Los Angeles to San Francisco; Eugene, Oreg., to Vancouver, B.C.; and Miami to Tampa via Orlando. Analysis of the results reveals common cost trends: for average speeds up to about 200 km/hr (125 mph), the initial investment required is generally in the range $1.6 to $3 million per route-kilometer ($2.6 to 4.8 million per route-mile). Above this speed regime (which varies by corridor), the initial investment increases steadily with speed, generally reaching $10 to $12 million per route-km ($16 to $19 million per route-mi) for very-high-speed rail systems and from $14 to $19 million per route-km ($23 to $31 million per route-mi) for Maglev systems. Analysis of the capital cost estimates reveals that despite the wide range of initial costs for the high-speed options, the cost per minute of trip time saved is remarkably consistent in corridors of similar length and with similar terrains. Cost-effectiveness plots are provided, allowing the reader to compare the performance of each of the four corridors in terms of trip time savings and cost per route-kilometer.

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