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Low rainfall limits crop yield, particularly for maize (Zea mays L.) in southern Africa. Consequently, there is a need to identify genetic sources of specific drought-related traits that can contri...

Ethylene propylene diene monomer (EPDM) rubber/zinc dimethacrylate (ZDMA)-samarium methacrylate (Sm(MA)3) rare earth complex as seals were prepared via in-situ formation of Sm(MA)3 to partially rep...

We present a picture of flux-driven ITG turbulence and associated transport with heat source and sink which reveals resilience and stiffness coupled with SOC type intermittent bursts. The transport...

The presented experimental results demonstrated the ability of NiTi and reused NiTi reinforcing bar to undergo cyclical strains, showing an improved cyclic, energy dissipation, damping properties a...

In this article, we combine the viscosity approximation method and proximal operator to propose modified proximal gradient methods for solving the unconstrained convex optimization problems. The bo...

The concept of magnetic induction of hyperthermia was first proposed by Gilchrist et al. in 1957. The physics is based on the simple principle that when exposed to an alternating magnetic field, the magnetic media can transform the electromagnetic energy to thermal energy, causing the temperature increase of any surrounding media or tissue. In biological tissue, normal cells usually possess higher heat resistance and resilience to temperature than tumor cells. As such, cancerous cells can be selectively destroyed by increasing the local temperature of the tissue to a desired temperature range (42–46°C), while ensuring healthy cells are unharmed.

Seismic resilience and continued operation of bridges after earthquakes are important seismic design criteria. A new seismic protection concept for integral bridge piers is explored that uses sliding bearings to separate the superstructure from the piers. The influence of sliding bearings on the seismic response of a representative 3-span integral highway bridge is investigated. With sliding bearings, the pier column shear force was limited to the bearing design friction force. Furthermore, the abutment ductility demands were found to be insensitive to the friction forces in the sliding bearings because the bridge displacement demands were controlled by the equal displacement rule.

The design of highway subgrades necessitates the estimation of strength and stiffness characteristics to a reasonably accurate extent. The present study provides details on investigations on the modulus of resilience of lateritic soils in the region of Dakshina Kannada in Southern India, using the cyclic tri-axial test equipment. The discussions also provide comparisons on similar studies performed using the portable falling weight deflectometer (PFWD), and the California bearing ratio (CBR) test. As part of this study, regression equations were developed in order to correlate the observations made using the PFWD and the CBR with the results obtained using the cyclic tri-axial test. It is felt that the regressions developed for estimating the modulus of resilience based on simpler experimental approaches such as the CBR, and the PFWD, will be of special advantage to pavement engineers in developing nations.

The present study investigates tactile, thermal, physiological comfort, and hand values of newly developed mulberry silk waste/wool blended fabrics for end use. Intimate blended fabrics S1 (65s/35w, 2/33 × 33 tex) and S2 (65s/35w, 2/25 × 25 tex) had higher resilience as well as warpwise extensibility, whereas union-blended fabrics S3 (100w × 65s/35w, 2/33 × 33 tex) and S4 (100w × 65s/35w, 2/25 × 25 tex) had high bending hysteresis, high tensile energy, lower coefficient of friction, and less geometric roughness. S1, S2, and S4 fabrics exhibited higher transmission properties against air and moisture vapor whereas S3 fabric showed superior thermal insulation properties. S1 found significantly different (p ≤ .05) from S2 in terms of smoothness, uniformity, and aesthetic appearance. Total hand value of developed fabrics showed its suitablilty for women’s light weight winter dress material and suitings, whereas union-blended fabrics were suitable for men’s winter suitings. Stoles, mufflers, throws, an...

Fabric compression is a decrease in intrinsic thickness with an appropriate increase in pressure. The compressibility of the terry fabric depends on fibre properties, yarn parameters, weaving parameters, loop length, loop density, loop geometry and post-weaving treatments. In this research, all the factors responsible for fabric compression have been studied. It is observed that loop density, loop length, loop-shape factor, pile yarn twist, pile yarn count, fibre length and pile yarn structure have a significant effect on the compression behaviour of the terry fabric. With increase in the loop-shape factor, loop length and loop density, the linearity of compression curve, resilience increases and specific compression energy reduces which depict that the fabric is getting better in terms of softness to touch. It is also observed that pile yarns produced from ring spinning, zero twist, MCU-5 cotton, porous yarn and finer yarn produce better terry fabric in terms of compression behaviour and surface properti...

The composite of polytetrafluoroethylene (PTFE) has been generally applied to dynamic seals in Stirling power systems due to its excellent self-lubrication and resilience. In this article, the tribological behavior of polyphenylene sulfide (PPS)-PTFE blends filled with nano-Al2O3 are investigated under different contact loads, sliding speed, and operating temperatures using a block-on-ring friction and wear tester. The results indicate that the addition of nano-Al2O3 could significantly improve the antiwear performance of the PPS-PTFE blend. Nano-Al2O3-filled PPS-PTFE composites have good tribological performance under high-temperature environments. When the content of nano-Al2O3 is 5 wt%, the wear rate of the composite is 276 times better than that of virgin PTFE and more than 150 times better than that of unfilled PPS-PTFE. Dynamic mechanical analysis (DMA) shows that the block of the movement of molecular chains of PTFE with the addition of nano-Al2O3 particles may be responsible for the significant de...

This paper describes an experimental study that was completed to investigate the resilient constitutive characteristics of a granular limestone, as well as to assess the applicability of conventional modelling within the framework of elasticity theory for the material that was studied. Test results corresponding to various stress paths are reported for a well-graded, sub-angular coarse sand. Noticeable differences are found with regard to the measured deformation responses when compared with those from linear elastic model predictions. On the basis of studying the stress–strain responses in terms of invariants, the authors conclude that the difference in the resilient responses of the material for various stress paths is largely due to the inherent nonlinear anisotropic nature of the material, and that stress-induced fabric associated with, for example, rearrangement of particles and particle connectivity should be taken into account for better interpretation of resilient behaviour of granular soil.

Various tests are used to characterise the strength and resilience of granular materials used in the subbase of a pavement system, but there is a limited understanding of how particle properties relate to the bulk material response under various test conditions. Here, we use discrete element method (DEM) simulations with a mechanistically based contact model to explore influences of the material properties of the particle on the results of two such tests: the dynamic cone penetrometer (DCP) and the resilient modulus tests. We find that the measured resilient modulus increases linearly with the particle elastic modulus, whereas the DCP test results are relatively insensitive to particle elastic modulus. The DCP test results are also relatively insensitive to inter-particle friction coefficient but strongly dependent on the particle shape. We discuss strengths and weaknesses of our modelling approach and include suggestions for future improvements.

Fiber cross section shapes, which have a direct influence on the physical properties of textile surfaces, are becoming more and more complex recently. There are also many important properties of the carpets such as luster, resilience, abrasion resistance which are impacted by the shape of the fiber cross sections. In this present paper, the influence of pile fiber cross section shape on compression properties of carpets was experimentally investigated under short and long-term static loadings. The material used was polypropylene carpets having two different pile fiber shapes: trilobal and hollow. The experimental results indicate that percentage thickness loss of carpets having hollow piles is slightly higher than carpets with trilobal piles in both short- and long-term static loadings. However, in the case of percentage recovery, similar values were obtained for the samples used in this study.

The subject of this paper is the compression behaviour of jute–polypropylene blended needle-punched nonwoven under wet conditions. It is essential to know the compression behaviour of the needle-punched fabrics under wet conditions because of its various applications like geotextiles and carpets. Needle-punched fabric samples were prepared based on the three-factor three-level Box–Behnken design of experiment to study the individual as well as interaction effects of process parameters of fabric weight, needling density and blend proportion of jute and polypropylene fibre blend on compression properties under wet conditions. Initial thickness, percentage compression, percentage thickness loss and percentage compression resilience are the compression properties considered. The compression properties under wet conditions were compared with their respective dry conditions. This study reveals that most of the wet samples show a slightly higher value of initial thickness, percentage compression and thickness lo...

The technologies of producing metallic matrix composites and SiC reinforced particles are determined by the gas/liquid and liquid/solid particle transfer. A new technology of producing particle-reinforced composites is presented, the preparation facility of the alloy-particle suspension is connected directly to a continuous casting installation equipped with a water-cooled Cu catalyst. Theoretically, the values of the technological parameters necessary for the homogenous distribution and the incorporation of the reinforcement particles are presented. The investigation and the characterization of the achieved composites was made from the standpoint of mechanic properties (tear resilience, hardness), chemical-structural properties (scanning electron micrograph (SEM) and energy dispersive X-ray spectroscopy (EDX)), and tribological properties (linear wear intensity, friction). Furthermore, the density difference and the size of the reinforcement particles influence the critical velocity of the SiC particles ...

The hardness (H) and resilience (R) of rubber vulcanizates were combined together in this paper, named as hardness–resilience product (H4R), and its relationship with the Akron abrasion loss was investigated using various styrene-butadiene rubber (SBR) vulcanizates possessing specific hardness and resilience characteristics as samples. For the unfilled SBR vulcanizates with different chain microstructure, possessing high elastic resilience and low hardness, the results showed that their Akron abrasion loss had a good linear relationship with the log(H4100R). This linear relationship also occurred when these SBRs were filled with 50 phr carbon black. For two particular types of SBR, after being filled with different fractions of carbon black and aged for different times, all their Akron abrasion losses (including unaged, aged for 24 h, and aged for 48 h) also had a good linear relationship with the log(H4100R). However, this linear relationship weakened for one of the SBRs after being aged for 48 h. In the...

In Greece, during the 1980s, 60% of the twin-block concrete sleepers designed for lines of mixed traffic and a maximum speed of 200 km/h, which were laid on a track with a maximum operational speed of 140 km/h, presented serious cracks. The existing theories could not justify the appearance of these cracks since the theoretically calculated actions on sleepers were much lower than the limit values. In this paper, a model for the determination of the load acting on the track's superstructure is presented. The basic parameters of concrete sleeper design considering the most adverse conditions of a railway network are investigated, and a methodology for calculating the load undertaken by each sleeper is proposed. Finally, numerical applications on twin-block and/or monoblock sleepers are presented, including the use of fastenings of high resilience.

Appearance stability of woven carpets has been a great problem in the carpet industry for years. In this research, analysis of the various components of the woven carpet structure was performed to identify the role each component plays in the phenomenon of thickness loss recovery. Short- and long-term static loadings were used to test various samples of pile height (9, 10, 12.5, and 14 mm) and pile density (1600 and 2400 piles/dm2). We found that acrylic-carpet structural parameters of pile height and pile density significantly affected the thickness-loss recovery. In short-term loading, the carpet samples exhibited remarkable recovery of thickness loss in the first 15 minutes. Acrylic carpets reached 80% to 93% and 74% to 89% of their initial thickness in 1 hour after the short-term loading and 24 hours after the long-term loading, respectively.

This paper investigates laboratory test methods for resilient modulus of foamed asphalt mixes. By comparing test results from different laboratory test methods, the effects of various stress states are identified. The indirect tensile resilient modulus test and the free-free resonant column test were found to yield stress states irrelevant to pavement structures, and to greatly overestimate resilient modulus. Triaxial resilient modulus test results showed that the role of foamed asphalt treatment is to transform the material behavior from that of typical unbound granular materials to that of partially asphalt-bound materials. Flexural beam tests indicated that when subjected to tension, the resilient modulus of soaked foamed asphalt mixes can be very low. Since triaxial and flexural beam tests each characterize one of the two most important stress states relevant to pavement design, test results from these two methods need to be combined to be used in design.

The scope of this study is to use a three-dimensional discrete element model to simulate the resilient response of an unbound granular material subjected to sinusoidal loading in a triaxial sample and to compare the simulated results to experimental results. A three-dimensional discrete element model, where each grain interacts with its neighbour grains, allows a micromechanical approach to modelling. By doing the sensitivity analysis on the input parameters the model can be evaluated and insight gained about the factors that affect the resilient behaviour. Uniform spherical grains were used in both the DEM simulations and in the triaxial experiments. Two contact models, linear visco-elastic and Hertzian, and two types of confinement, a uniform cylinder and a flexible membrane, are tested in the simulations. Comparison of the simulation results with the results of similar laboratory experiments shows that the discrete element approach is suitable to model idealised aggregate grains.

Asian noodles were simultaneously cooked and dried in superheated steam at temperatures from 110 to 150°C and steam velocities of 0.5, 1.0, and 1.5 m/s. Textural and key physical properties of color, breaking stress, and starch gelatinization were measured to ascertain the effects of the superheated steam processing. Textural properties of adhesiveness, springiness, cohesiveness, chewiness, resilience, and hardness determined from a TPA were found to be generally unaffected by steam velocity. All properties but springiness increased with an increase in processing time. Increasing temperature decreased adhesiveness, springiness, cohesiveness, and resilience but increased hardness and chewiness to a small degree. Processing time greatly affected noodle color, resulting in browning at greater processing times. Results show that velocity was not a significant factor (p > 0.05) on the breaking strength of noodles. Temperature was only significant (p

The unbound granular materials (UGM), base and subbase layers, play an essential role in the overall structural performance of thin pavement structures. They show complex stress dependent elasto-plastic behaviour under external loading. Therefore the UGM are commonly tested using the Repeated Load Triaxial (RLT) testing method to estimate the stiffness of the material by applying haversine loading pulses. The RLT testing method represents the actual stress situation quite adequately and gives satisfactorily estimates of the stiffness characteristics of UGM. A simple test that has been used for a long time in structural design of flexible pavements is the CBR (California Bearing Ratio) test. In the CBR test, the load-deformation curve is acquired while a plunger is penetrated into the material at a constant rate. In the literature one can find a number of relationships for UGM where the CBR value is used to predict the stiffness. These connections usually do not take into account that stiffness of...

A commercial modified glyoxal-based resin product is used for the chemical end-finish of linen and ramie fabrics in wet fixation with standard curing time. The finishing technology recommended by the manufacturer significantly spoils the tensile and tearing properties, and decreases the resilience of the fabrics, and results in a considerable increase exclusively in wet crease recovery angle. The ramie is more sensitive to the applied finishing and expresses a greater strength loss than linen. Concentration of resin and acid has significant effect on both tensile and crease recovery properties, while concentration of the softener affects only the resilience of the fabrics.

Summary When pressure vessels are constructed, the goal is to obtain the properties of resilience and tenacity necessary to the non-propagation of fissures by applying appropriate dehydrogenation treatments (DHT) for the zones close to the weld and a relaxation (ISR) for the welds. This study, carried out on steel of the grade 13CrMoV9.10, shows that intermediate treatments can be optimised for temperature and duration, provided that a final post treatment (PHWT) at 705°C for 8 to 10 hours is ensured. Document presented during the European Symposium on Pressure Equipments 2004 (ESOPE 2004), in the Manufacture, Welding and Control commission. This event took place from the 28th to the 30th September 2004 at the Palais des Congres, Paris.

To describe important thermal properties of high temperature insulating wool (HTIW) materials, firing experiments have been performed at temperatures above their classification temperature and following shrinkage and resilience measurements for three HTIW material groups: AES (alkaline earth silicate wool), aluminium silicate wool (RCF) and polycrystalline wool. A temperature range of 1000–1600°C has been chosen. At industrial application temperatures the HTIW products should not reveal significant shrinkage behaviour, and their mechanical properties should be maintained after exposure to elevated temperatures. This is an important and critical aspect for these high temperature insulation materials. Microstructural examination after firing at different temperatures shows increasing crystallisation as a result of phase formation, leading to increased density and shrinkage. At classification temperature these processes enhance bending of fibres and fibre thickness in the length direction which also ...

Subgrade soil characterization, in terms of resilient modulus, is crucial for both flexible and rigid pavement design. Resilient moduli measured through repeated triaxial load tests on cylindrical disturbed/undisturbed samples are frequently used for characterizing subgrade soil. Because of the complexities encountered with the test, in-situ and other laboratory tests would be desirable if a reliable correlation can be established. In this paper, data from two-field test programs was used in developing correlation equations to predict resilient modulus of fine- and coarse-grained soils. Undisturbed samples are extracted from 12 in-service Mississippi subgrades, using a Shelby tube, and tested in a repeated triaxial machine for M R employing AASHTO TP46-94 protocol. The results suggest two comprehensive models—one for fine-grained and another for coarse-grained soil—in correlating laboratory M R to stress state. Model parameters are then correlated with soil index properties allowing the models to capture ...

The measurement of resilient modulus has become increasingly accepted for characterizing the engineering properties of pavement materials. This paper presents an experimental program utilizing the Florida DOT test-pit facility and laboratory triaxial equipment to conduct the resilient modulus measurement of granular pavement subgrade materials in Florida. The resilient modulus was significantly affected by the moisture content of granular subgrades. A comparison between the resilient moduli measured from the test-pit test and the laboratory test was made. It was experimentally verified that the resilient modulus resulting from the laboratory triaxial test could be used to predict the resilient deformation of the pavement layer.

The effects of high styrene (HS) resin on the Mooney viscosity, scorch time, cure time and physical properties of rubber vulcanizates were evaluated. The Mooney viscosity decreased with increasing HS composition up to 20% after which it started to increase. The incorporation of HS was found to increase the scorch and cure times of the rubber vulcanizates. Physical properties i.e., hardness, tensile modulus (M 100) and resilience also increased with increasing HS composition. However the opposite trend was observed in the case of crosslink density.

Cure characteristics and mechanical properties of natural rubber/reclaimed rubber blends were studied. The minimum torque values of the blends were lower than that of the gum compound. The (maximum–minimum torque) and scorch time decreased with increasing reclaim content. The cure rate of the blends were lower than that of the virgin compounds. The tear strength was improved by the addition of reclaimed rubber. Tensile strength, elongation at break, and resilience decreased with increasing reclaim loading. The heat buildup was higher for the blends.

Summary High tensile, microalloyed steels, such as the 450 EMZ design steels which are studied in this article, are used in offshore platforms and other structures subject to extreme working conditions, requiring high resilience and fracture toughness at low temperatures. These steels have been subject to controlled welding parameters in order to obtain a low heat input which allows for the maintenance of correct toughness values in their heat affected zone (HAZ). The present article analyses the hardness, resilience and toughness values, as well as the most brittle points of the HAZ.

Systems of combined accelerators comprising 2-mercaptobenzothiazol (MBT), dibenzothiazyl disulfide (MBTS), tetramethyl thiuram monosulfide (TMTM) and diphenyl guanidine (DPG) were used to study the physical properties of rubber vulcanizates. The study was conducted by divisioning the work into 3 sets; namely set 1, set 2 and set 3 whereby the combinations of the accelerators were carried out in such a way that only the ratios were subject to changes. We found that there was a synergistic effect on the vulcanizates properties leading to, higher or lower property values from the normally expected ones demonstrating the role of crosslink on tensile modulus, hardness and resilience.

Little information is available in the literature about double-rove spun yarn's low-stress mechanical properties. An experimental investigation has been made in a short-staple spinning system to study the effect of strand spacing, twist, and spindle speed on a double-rove yarn's compressive resilience, and compressibility at low-stress levels. The response-surface equations developed from the experimental results, have been used to explain the compressional behaviour of the yarn studied.

Spunbonded nonwoven fabrics are extensively used in a number of technical applications because of their physical, tensile, and hydraulic characteristics. In many cases, fabric is subjected to normal compressive loads, and the physical, tensile, and hydraulic properties change with these loads depending on the compressional behaviour of the fabric. It is important to characterise the compressional behaviour of fabrics before their effective use in these applications. Two parameters, α and β, describing compression and recovery curves of different types of spunbonded fabrics have been evaluated. A comparative study on the compressional behaviour of different types of spunbonded-fabric structure is reported. The compressibility of spunbonded heat-sealed fabrics has been found to be much lower and their compressional resilience much higher than the compressibility and compressional resilience of needle-punched spunbonded fabrics. The compressibility of surface-calendered needle-punched spunbonded fabrics is l...

To optimize the improvements by diketones of the mechanical properties of resin composites, diacetyl was added to two different monomer mixtures in different quantities. There was a positive correlation between content of diacetyl and tensile strength, flexural strength, and modulus of elasticity, respectively, of both the BISGMA/TEGDMA- and the UEDMA/ HEMA-based materials. Addition of diacetyl did not influence the modulus of resilience significantly. Addition of diacetyl resulted in increases in mechanical properties which were of the same relative size for BISGMA/TEGDMA-based materials as for UEDMA/HEMA-based materials. However, because of higher control values, except for modulus of elasticity, the properties of UEDMA/HEMA-based composites were superior to those of the BIGSMA/ TEGDMA-based materials. A content of approximately 24 mole% diacetyl seemed to have optimum effect on mechanical properties, giving a mean increase of 25% in tensile strength, flexural strength, and modulus of elasticity. □ Dent...

Effect of fiber concentration on the physical properties such as tensile strength, tear strength and elongation at break, flexing resistance, heat buildup, compression set, permanent set, hardness, resilience and aging resistance of natural rubber filled with treated short glass fiber has been studied. The effect of carbon black on the physical properties and processing characteristics of the fiber-rubber composites has also been studied at different fiber concentrations. Scanning electron microscopy studies have been made in order to assess the failure criteria.

The three commonest polymers used for foam-rubber carpet-backing are polyisoprene (natural rubber (NR)), styrene–butadiene rubber (SBR), and carboxylated styrene–butadiene rubber (C-SBR). Each polymer has different properties and contributes to the characteristics of the carpet-backing foam. A study is reported in this paper of the properties of carpet-backing foams prepared from the polymers under comparable conditions. The compression modulus of the foam for NR is equivalent to that for SBR but lower than that for C-SBR. However, flex loss and the effect of water-soaking are greater for SBR and C-SBR. The same trend is seen for the delamination resistance. hysteresis loss, resilience, and tearing strength. The ageing of the systems is discussed. The present position with regard to specifications for carpets is briefly outlined and the effect these have on the polymer choice examined.

(1983). Mechanical Properties and Cutting Performance of Sintered M2 High Speed Steel. Powder Metallurgy: Vol. 26, No. 3, pp. 145-148.

The relevance of the extensional recovery of single filaments to the resilience of textiles is discussed, and tests are described that yield information at three different effectiverates of loading. The methods considered are: (i) cyclic measurements on an Instron Tensile Tester; (ii) recovery from a sustained extension; and (iii) recovery from impact. Applications of these methods will be discussed in two later papers.

A series of polypropylene-fibre continuous-filament yarns was used to manufacture a set of simplified carpet-like structures. Recovery and wear tests on these samples are described and the results ...

Differential thermal analysis (DTA), rebound resilience, and tensile proerties of a polyurethane adhesive were measured at cryogenic temperatures. The experimental methods are described, and test results which aid in evaluating the polyurethane for use at low temperatures are discussed. The DTA thermogram reveals that the glass transition temperature (Tg) is 235°K. The resilience profile indicates a resilience minimum (Tr) at 270°K and a frequency of 3800 Hz, which is consistent with the Tg measured by DTA. The low resilience below Tr, caused by secondary low-temperature transitions, shows the high energy absorption capabilities of the polyurethane. Considerable plastic flow at 195°K (40°K below Tg) is evidenced in the results of the tensile tests. The results of the three tests indicate that the polyurethane adhesive will perform well at low temperatures. The test methods should also be useful for evaluating the low-temperature performance of new polymers.

Three empirical test methods of determining the extensional recovery of textile fibres have been reported in the previous paper. Data are now presented to demonstrate how recovery depends on the test material and its method of preparation, the strain, the rate of strain, the time under load, the number of times the load is applied, and the temperature at which testingis done. The importance is stressed of ensuring that test conditions cover the range of deformation experienced by the finished product.

The mechanical properties of certain chemically modified cotton textiles studied in considerable detail mostly at the Southern Utilization Research and Development Division are summarized, Properties studied include breaking strength, yarn knot strength, tearing strength (Elmendorf). ultimate elongation, average tensile and flexural stiffness (modulus), toughness index (work of rupture), frictional behaviour, creep, elastic recovery, resilience and abrasionresistance (flat and flex). Chemical modifications have included many types, but only those which increase the weight of the cellulose molecule through substitution of the hydroxyl groups are included in the present report. Among these are substitution with acetyl, cyanoethyl, carboxymethyl, carboxyethyl (β-propiolactone) and benzyl groups. The changes in various mechanical properties are related to type of product (fibre, yarn or fabric), degree of substitution, conditions imposed during treatment and construction of the textile. The ‘dilution’ effect,...

A method of combined radio-frequency and hot-air finish drying of a textured mass of fungal mycelial, fibers is described. The finished product may be rehydrated to more than twice its initial dry weight. The resilience of the rehydrated product depends on the moisture level at which prepuffing is terminated.