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In recent years, statistical studies highlighted an increasing incidence of cardiovascular diseases (CVD) which reflected on additional costs on the healthcare systems worldwide. Pulse wave velocity (PWV) measurement is commonly considered a CVD predictor factor as well as a marker of Arterial Stiffness (AS), since it is closely related to the mechanical characteristics of the arterial wall. An increase in PWV is due to a more rigid arterial system. Because of the prevalence of the elastic component, in young people the PWV is lower than in the elderly. Nowadays, invasive and non-invasive methods for PWV assessment are employed: there is an increasing attention in the development of non-invasive devices which mostly perform a regional PWV measurement (over a long arterial portion) rather than local (over a short arterial portion). The accepted gold-standard for non-invasive AS measurement is the carotid-femoral PWV used to evaluate the arterial damage, the corresponding cardiovascular risk and to adapt the proper therapy. This review article considers the main commercially available devices underlining their operating principles in terms of sensors, execution mode, pulse waveform acquired, site of measurement, distance and time estimation methods, as well as their main limitations in clinical practice.

Fabric deformation properties considerably depend on its structure. Garment elasticity is an important factor that allows a garment wearer to move freely. Fabric deformation depends on the structure parameters of yarrn and fabric. It has been known that elongation at break of fabric with elastane yarn is higher than of ordinary fabric. The aim of this work was to analyse elongation at break parameters of the and warp and weft yarn in fabrics. Ten commercially produced samples of woven fabrics were used in the experiment. Some samples were with elastan yarn in the warp and weft directions or only in the weft direction. Elongation at break was measured applying a standard method. The results showed that elongation at break of the main elastic component or another component may occur simultaneously when an elastic component or elastane yarn may reach fabric ultimate elongation.

By studying dynamic characteristics of the leaf spring system, a new elastic component is designed to reduce the working load and to a certain extent to ensure the linearity as well as increase the amplitude in the vertical and horizontal directions in vibration screen. The modal parameters, amplitudes, and amplification factors of the leaf spring system are studied by simulation and experiment. The modal results show that the leaf spring system vibrates in horizontal and vertical directions in first and second mode shapes, respectively. It is conducive to loosening and moving the particles on the vibration screen. In addition, it is found that the maximum amplitude and amplification factor in the horizontal direction appear at 300 r/min (5 Hz) while those in the vertical direction appear at 480 r/min (8 Hz), which are higher than those in the disc spring system. Moreover, the amplitude of the leaf spring system increases proportionally with the increase of exciting force while the amplification factors are basically the same under different exciting forces, indicating the good linearity of the leaf spring system. Furthermore, the minimum exciting force occurs in the leaf spring system under the same amplitude by comparing the exciting force among different elastic components. The above works can provide guidance for the industrial production in vibration screen.

The long-term effect of climate factors, such as sunlight, oxygen, and water, leads to the performance degradation of the asphalt mastic, which is the binding part in the asphalt mixture. It is not conducive to satisfy the long-term performance requirements of long-life asphalt pavement. In this study, five kinds of base asphalt mastic and styrene-butadiene-styrene (SBS) modified asphalt mastic were prepared with the filler-asphalt ratio of 0.6, 0.8, 1.0, 1.2, and 1.4. The indoor simulated weather aging tests were carried out considering multi-factors including sunlight, oxygen, and water. The master curves of the complex shear modulus and phase angle of the asphalt mastic with different aging degrees were obtained by the frequency sweep test. The curves of fatigue damage characteristics and fatigue life were fitted based on the viscoelastic continuum damage (VECD) model. The influence of weather aging on the viscoelasticity and fatigue performance of asphalt mastic were analyzed. Results indicated that the effect of weather aging increases the elastic component and decreases the viscous component. The fatigue performance of SBS modified asphalt mastic was better than that of base asphalt mastic. As the aging degree deepens, the brittle failure characteristics of asphalt mastic with a higher filler–asphalt ratio were more obvious. The base asphalt mastic becomes more sensitive to the strain level due to weather aging, and its fatigue life increased under the low strain loading and decreased under the high strain loading. The fatigue performance of SBS modified asphalt mastic was less sensitive to the strain level. The fatigue life reduced after aging under low and high strain load. Taking the impact of weather aging on the fatigue performance into consideration, the optimal filler–asphalt ratios of the base asphalt mastic SBS modified asphalt mastic are 1.0 and 1.2, respectively.

The application of braking systems with the lo-cation of the executive mechanism directly upon a bogie is a promising trend in domestic brake production and freight car manufacturing on the whole. In the paper a common circuit of a braking rod leverage with the location of cylinders 670V on the bogie of two-axle type 2 and type 3 (RSS 9246-2013) is considered. The investigation carried out in the work is a continuation of works connected with the updating of a braking system developed earlier. The aim of the work consists in the definition of cylinder rod outlet limits taking into account elastic deformation of all elements of leverage in accordance with the procedure developed and appraised earlier and also the definition of maximum possible thickness of a brake pad used for this circuit in operation. The rod outlet limits obtained will be standard as system transmission ratio is unified, and an elastic constituent will have minimum deviations from the value obtained and depend upon a specific execution of elements. In this investigation there is used a 3D brake system model developed thoroughly that allows obtaining an elastic deformation value precise enough. Furthermore, data obtained allow defining a maximum operation outlet of rod of the braking cylinder 670V in the system analyzed during car motion on a long steep slope. On the basis of the investigations carried out there are defined the limits of rod outlet (35…47mm) for the developed common brake system with cylinders 670V that allows using brake pads of maximum width (65+5mm) used in railway freight rolling-stock of the RF. The maximum operation value of rod outlet is obtained during car motion on a steep long slope (63mm) which does not exceed a working stroke of a cylinder (100mm).

Adulteration of foods has been known to exist for a long time and various analytical tests have been reported to address this problem. Among them, authenticity of sesame oil has attracted much attention. Near-infrared (NIR) spectral quantitative detection models of sesame oil adulterated with other oils are constructed by chemometric methods, i.e., competitive adaptive reweighted sampling (CARS), elastic component regression (ECR) and partial least squares (PLS). Sixty samples adulterated with different proportions of five kinds of other oils of lower price were scanned by a Fourier-transform-NIR spectrometer and the NIR spectra were collected in 4500–10000 cm−1 region by transmission mode. All samples were divided into the training set and an independent test set. Model population analysis has also been carried out and confirms the importance of selecting representative samples. The experimental results indicate that the PLS model using only 10 variables from CARS and the ECR model show similar performance and both are superior to the full-spectrum PLS model. CARS focuses on selecting variables and ECR focuses on optimizing the parameters, implying that both roads lead to the same destination. It seems that NIR technique combined with CARS or ECR is feasible for rapidly detecting sesame oil adulterated with other vegetable oils.

We measure the resonant forward scattering of light by a highly saturated atomic medium through the flashes emitted immediately after an abrupt extinction of the probe beam. The experiment is done in a dilute regime where the phenomena are well captured using the independent scattering approximation. Comparing our measurements to a model based on Maxwell-Bloch equations, our experimental results are consistent with contributions from only the elastic component, whereas the attenuation of the coherent transmission power is linked to the elastic and inelastic scatterings. In the large saturation regime and at the vicinity of the atomic resonance, we derive an asymptotic expression relating the elastic scattering power to the forward-scattered power., Comment: 11 pages, 4 figures

In this study, new artificial dura-mater models were developed using a multilayered structure of a rubber material (represent an elastic component of a dura-mater) and a fiber sheet (represent fiber component of a dura-mater). The artificial dura-mater models were prepared for use in a brain surgery simulator, especially for transnasal pituitary surgery. The mechanical characteristics of the artificial dura-mater models were tested to check the similarities with porcine dura-mater. Tensile stress, viscoelasticity, and the cutting force generated by microscissors were tested to evaluate the fabricated models. Neurosurgeons also assessed the dura-mater models to evaluate their characteristics. The results indicate that these models made of two different non-woven fiber sheets emulated accurately the actual dura-mater.

Legumes and cereals complement their nutritional quality and there is a need of convenience products made with these grains. The objectives of this study were to determine the rheological and functional properties of precooked red kidney bean (RKB) flours and their effect on viscoelastic properties of gluten free cake batter and cupcake quality including consumer acceptance. RKB flours were thermally processed by boiling at 100 °C (0, 20, 30 and 40 min) and drying at 80 °C (3 and 4 h). Rheological properties of cake batter containing 100% RKB flour were tested by creep-recovery and dynamic frequency tests. Batter of RKB flour boiled for 20 min was significantly stiffer with 100 times less deformable character compared to the control. Increase in batter modulus ranged from 2000 times elastic component (G′), 988 times viscous component (G″) and 1805 times complex viscosity (η*) at 20 min boiling. Drying did not have a significant effect on viscoelastic properties. Firmness and height of gluten free RKB cupcake were not affected by heat treatment. RKB gluten free cake after heat-moisture treatment had improved consumer acceptance scores compared to the control. Our findings showed that 20 min boiling and 3 h drying process is adequate for precooked RKB flour.

The wool content in textiles is a key quality index and the corresponding quantitative analysis takes an important position due to common adulterations in both raw and finished textiles. Conventional methods are maybe complicated, destructive, time-consuming, environment-unfriendly. Developing a quick, easy-to-use and green alternative method is interesting. The work focuses on exploring the feasibility of combining near-infrared (NIR) spectroscopy and several partial least squares (PLS)-based algorithms and elastic component regression (ECR) algorithms for measuring wool content in textile. A total of 108 cloth samples with wool content ranging from 0% to 100% (w/w) were collected and all the compositions are really existent in the market. The dataset was divided equally into the training and test sets for developing and validating calibration models. When using local PLS, the original spectrum axis was split into 20 sub-intervals. No obvious difference of performance can be seen for the local PLS models. The ECR model is comparable or superior to the other models due its flexibility, i.e., being transition state from PCR to PLS. It seems that ECR combined with NIR technique may be a potential method for determining wool content in textile products. In addition, it might have regulatory advantages to avoid time-consuming and environmental-unfriendly chemical analysis.

The present study substituted (a) casein (CR) and (b) casein and fat (CR + FR) simultaneously with cold water‐soluble (CWS) rice starch citrates and lactates to control functional characteristics of imitation cheese (IC). Rheological analysis for cheese confirmed the dominancy of elastic component (G′ > G″) and pseudoplastic behavior with flow behavior index less than 1. Lactic acid‐modified CWS displayed better structural alignment with progressive rise in frequency as evident by rise in G′. Meltability of CR cheese samples containing modified starches showed no significant difference with respect to control. Cohesiveness significantly increased, whereas adhesiveness showed no difference for CR cheese samples when compared with control. These distinctive properties provide a scientific approach to control stretching, rheological/textural properties, and meltability of imitation cheese (IC) by using precise ratio of casein and fat along with modified starches. PRACTICAL APPLICATIONS: Starches modified by safe chemicals were used to partially replace fat and casein simultaneously in IC. Therefore, the present study will lead to development of low‐cost cheese, which will ultimately generate higher revenues for industry. Also it will reduce load of calories while improving/retaining quality of cheese.

Cushioning of packaging materials is normally evaluated in terms of the maximum deceleration versus the “static stress” for a specific drop height (h) and cushion thickness (d) (ISO 4651:1988 (E)). These standard methods provide a general guidance to the evaluation of cushioning performance but require extensive work to build the curves for all the desired height to cushion thickness ratio (h/d). Moreover, they offer no insight into the material’s structure–performance relationships so it is difficult to compare different materials. Several authors approached the problem with empirical formulas, finite element analysis or parametric fitting to describe cushioning performances. Here we focus on the cushioning behavior of EPS (expanded polystyrene) which we show can be modeled with two contributions: a recoverable nonlinear elastic component due to the air compression and a non-recoverable ideal cushion due to the plastic collapse of the foam. We show how these two components are enough to describe the cushioning curve of EPS.

The work described here has led to a simple criterion that defines the boundary of the small-scale yielding, SSY, regime to avoid invalid use of the LEFM parameter, ΔK, as the characterising parameter for fatigue crack growth rate. The approach proposed is based on the analysis of crack tip opening displacement, CTOD, and its separation into elastic and plastic components. SSY conditions are shown to dominate when the elastic component of CTOD is >75% of the total CTOD measured at a distance of 8 μm (the finite element mesh size) behind the crack tip, i.e., Δδe/Δδt > 75%. Large-scale yielding, LSY, conditions become dominant for relatively large values of plastic CTOD, Δδe/Δδt

This study analyzed the feasibility of modifying the asphalt binder with the waste leather (WL). The 70# base asphalt was selected as the base matrix and four samples with different waste leather content were prepared. The test results indicated that the rotational viscosity of the waste leather modified asphalt was obviously higher than that of the original binder. Furthermore, it is found that the added waste leather increases the elastic component of the asphalt through the dynamic shear rheometer (DSR) test, thus enhances the high-temperature rheological properties and creep recovery ability of the asphalt. The modification with waste leather can also enhance the anti-aging properties of the asphalt and the enhancement effect generally increases with the leather content. The fourier transform infrared spectroscopy (FTIR), results indicate the modification with the waste leather is mainly a physical process without changing the chemical structure of the asphalt binder. This study pcreates new recycling routes for the waste leather and provides a considerable reference for the application of the waste leather modified asphalt binder.

Objective: To examine muscle-specific differences and the effects of fatigue and recovery on electromechanical delay (EMD) during maximal isokinetic muscle actions. Approach: Thirteen men performed maximal isokinetic knee extension muscle actions at 60° s−1, pretest, posttest, and after 5 min of recovery from 25 maximal isokinetic knee extensions. The onsets of the electromyographic, mechanomyographic, and force signals were used to identify EMD measures from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF). Main results: There were posttest increases in all EMD measures for all muscles that returned to pretest levels after 5 min of recovery. There were, however, no differences in EMD measures between the VL and VM. All EMD values from the RF were greater than the VL and VM. Significance: These findings suggested muscle-specific differences in EMD and that excitation-contraction coupling failure and increased compliance of the series elastic component occurred posttest, but subsided after 5 min of recovery.

Two commercial highly-concentrated detergents have been studied as model systems in order to estimate the yield stress using different methodologies. Both exhibit clear viscoelastic properties with long relaxation times; the elastic component being dominant on the viscous one. They show different yield stress and time-dependent flow properties. While one of them exhibits apparent thixotropy, the other shows a thixotropy/antithixotropy transition, which predicts the occurrence of complex shear-induced microstructural transitions and the need to strict process control. Their flow curves illustrate the different fluidity of both gel detergents, which show standard shear thinning and “very shear thinning” properties, respectively.

Introduction The onsets of the electromyographic (EMG) signal, mechanomyographic (MMG) signal, and force production were used to identify voluntary electromechanical delay (EMD) during maximal and submaximal leg extensions. Methods Twelve men performed 30% 1-repetition-maximum concentric, dynamic constant external resistance leg extensions to failure. The time periods for the onsets of EMG to MMG (EMDE-M ), MMG to force (EMDM-F ), and EMG to force (EMDE-F ) were assessed before, during, and after testing. Results Pretest vs. posttest assessments indicated approximately equal contributions from excitation-contraction coupling (EMDE-M ) and series elastic component (EMDM-F ) to the overall EMDE-F . During the workbout, excitation-contraction coupling failure and increases in the compliance of the series elastic component began at 40% and 30% of the repetitions to failure, respectively, and continued to failure. Conclusions Increases in the series elastic component (EMDM-F ) began to affect EMDE-F before excitation-contraction coupling failure (EMDE-M ), and both contributed to EMDE-F throughout the remainder of the fatiguing workbout. Muscle Nerve 56: 315-320, 2017.

Effects of different visual conditions on the vertical posture maintenance were compared in subjects standing on a firm or compliant surface. These visual conditions included a motionless visual environment (MVE), eyes-closed condition (EC), and a virtual visual environment (VVE). The VVE consisted of two planes: the foreground and background. The foreground displayed a room window with adjacent walls, and the background was represented by an aqueduct with the adjacent landscape. The VVE was destabilized by inducing either the cophased or the antiphased relation between the foreground of the visual scene and the body sway. We evaluated changes in the amplitude spectra of two elementary variables calculated from the trajectories of the plantar center of pressure (CoP) displacements in the anteroposterior and lateral directions, namely, the trajectories for the center of gravity projections on the support (the CG variable) and the differences between the CoP and CG trajectories (the CoP–CG variable).The CG trajectory was considered as a controlled variable, and the difference between the CoP and CG trajectories were considered as a variable related to the body acceleration and reflecting changes in the resultant stiffness in ankle joints. The rootmean-square (RMS) values for the spectra of both variables calculated from the body sway in the anteroposterior direction in standing on a firm support decreased proportionately with antiphased relation between the foreground and the body sway and increased with the cophased relation, compared with the RMS calculated for the MVE conditions. RMS for the spectra of the CG variable in the cophased relation were nearly the same, as in standing with eyes closed (EC), while the RMS for the spectra of the CoP–CG variable were significantly less than with EC. The body sway during standing on a compliant support significantly increased in both the anteroposterior and the lateral directions under all visual conditions. RMS for the spectra of both variables with EC increased considerably higher than in the cophased relation. Furthermore, the RMS for the spectra of the CG variable calculated from the body sway in the lateral direction on a compliant support was substantially higher in the antiphased relation than in the cophased relation, whereas the RMS for the spectra of the CoP–CG variable under both conditions had similar values. The analysis of body sway and the results under some visual conditions have shown that the amplitude characteristics of the CG and CoP–CG variables changed not always proportionately with the passage from standing on a firm support to a compliant support. It is suggested that the found disproportion of changes in these two variables is probably associated with the contribution of another additional factor to the process of postural control, the passive elastic component of musculo-articular stiffness generated by fascial-tendon tissues.

The pasting and rheological properties of waxy rice powder (WRP) with high-temperature baking (140–180 °C) and the fine structure of its starch were investigated. Rapid visco-analysis showed that the viscosity and breakdown value of baked WRP decreased obviously compared to its native counterpart, and this trend was greatly increased under higher temperature. Rheological analysis indicated that the baked WRP had relatively more elastic component compared to viscosity component but was less thixotropic than native WRP, suggesting the swelling of starch granules and the leaching of starch molecules were retarded when the WRP was baked at high temperature. Additionally, WRP was severely degraded and further re-associated and interacted with other granules during high-temperature baking. Changes in starch fine structure contributed to the alteration of pasting and rheological properties of WRP. These findings suggest that high-temperature baking induced structural changes of starch and thus reduced the viscosity of WRP.

The usual test to obtain the better superplasticizer (SP) to be used and also their content in the admixture is the Marsh cone test, but it demands a lot of material to perform it. On other hand, the use of the parallel-plate rotational rheometry allows achieving those answers using very few materials and in a fast way. In this research, three different pastes were tested to see which one had the longer workability period, performing oscillatory time sweep test. This test allows observing the behavior of the elastic component (G′) in the time, fact that some authors correlated with the setting time. After choosing the SP that obtained the best behavior over time, flow tests in pastes with different amounts of additive were performed to obtain the saturation point. With the viscosity results, it was possible to analyze when the SP no longer influences this parameter. It was observed that very few materials were used in these tests, an important factor when working with expensive or rare materials. Determining the superplasticizer that did not indicate delay in casting time and their saturation point, could guarantee that the additive did not affect the compatibility between materials in the admixture.

Body weight support (BWS) system is widely used for patients to help their gait training. However, that existing systems require large workspace and elastic component in actuation makes the systems inappropriate for wide clinical use. The interactive treadmill was reported to be cost/space effectively simulate overground walking, but there was no suitable BWS system for the treadmill. We proposed a new concept of body weight support system for interactive treadmill. For wide clinical use, we applied a two-wire driven mechanism with simple actuator and a custom pelvic-type harness. With three healthy subjects, the performance of the proposed BWS system on unloading force control was evaluated, and the result showed that the feasibility of the proposed BWS system.

Arteries are elastic structures containing both elastin and collagen. While the high content of elastin is understood to be important for the elasticity of arteries with systolic and diastolic pressure pulses, the role of collagen in the elastic properties of arteries is less understood. Here we use small angle X-ray scattering to investigate the changes in arrangement of collagen fibrils and the strain experienced by collagen fibrils as arteries are inflated. Collagen fibrils re-orient to become more aligned in both the annular direction and radially as arteries inflate. With arterial pressures up to 32 kPa there is no observable increase in D-spacing of the collagen fibrils (0.1%) indicating that there is no extension of straightened fibrils and therefore no change in stress on the collagen fibrils. This is in contrast to tissue such as skin where stress of the tissue may induce strains in collagen fibrils of6%. In arteries the collagen fibril elasticity (strain at the scale of fibrils) is not the main elastic component of the arterial walls. This indicates that wall elasticity is dominated by other factors such as the structural arrangement of the collagen fibers.

This study focuses on the "running" component in football, putting attention to the biomechanical and coordinative aspects rather than to the conditional abilities alone. Poor running technique can be linked to heavy impacts. The objective is to find a correlation between the number of impacts and the VO2max value. Ten young footballers, aged between 13-14 y.o., performed the Gacon test. During the test the number of impacts between 3-5g was recorded with a GPS tracking unit. A correlation was computed between the distance covered and the number of impacts per stage. Another correlation was calculated between the average number of impacts and the number of stages performed. No significant correlation was found between the meters travelled and the number of impacts recorded. On the contrary, a positive correlation (+0.8) was found between the average number of impacts and the total stages performed in the test. Findings suggest the number of impacts does not seem to be indicative of fatigue, while it seems that athletes with a higher V02max (more stages performed) have more impacts than athletes with lower VO2max. It can also be considered that the impacts between 3-5g, not detrimental to the body, are an indicator for good use of the muscular elastic component during the running.

International audience; PurposeReaction time, classically divided into premotor time and electromechanical delay (EMD), can be determinant in daily life or sport situations. While some previous studies reported a negative impact of both muscle and mental fatigue on reaction time, the respective contributions of premotor time and EMD to the changes of reaction time remains unclear. The aim of the study was, therefore, to assess the effects of both muscle and mental effort on reaction time and its components.MethodsThirteen subjects performed three conditions (mental effort condition, i.e., 14 min of a mathematical cognitive task; muscle effort condition, i.e., intermittent contractions of the biceps brachii; control condition, i.e., watching a documentary). Before and after each condition, reaction time, premotor time and EMD were measured during voluntary contractions of the biceps brachii. EMD was also measured during evoked contractions of the biceps brachii to separate the parts due to the onset of muscle fascicle motion and the onset of force production.ResultsReaction time and premotor time remained stable regardless of the condition considered (all P values > 0.05). EMD increased only after the muscle effort condition (+ 25% during voluntary contractions, no significant; + 17% during evoked contractions, P = 0.001), mainly due to an increase in the passive part of the series elastic component.ConclusionOur study showed that neither mental nor muscle effort has a negative effect on simple reaction time during voluntary contractions.

The differences in viscoelastic properties of gluten from two very different wheat flours, a weak soft flour dough and a strong semolina dough, primarily caused by their gliadin and glutenin content including gliadin to glutenin ratio were studied. The doughs were subjected to oscillatory time sweep tests at small and large amplitudes as well as small and large frequencies. The gluten subunits (LMW, HMW glutenins and gliadins) tagged with specific fluorescent quantum dots with a distint excitation wavelength were imaged with confocal laser scanning microscopy and their distribution and interactions were measured. The quantitative imaging data was converted into networking data that included lacunarity, network area, and number of network junctions. This networking data was correlated with rheology. The two different dough systems showed different oscillatory behavior during time sweeps. The critical role of LMW glutenins in keeping the structural integrity of semolina doughs was demonstrated by a direct correlation between the non-linear elastic component ‘e3/e1’ of the dough and protein network parameters of LMW glutenins. It was also shown that gliadins and HMW glutenins co-localize and associate throughout rheological deformations of the dough. The disruption of the three gluten subunits are responsible for rheological breakdown of soft wheat flour dough, with gliadins influencing the breakdown of the network at higher amplitude deformations. This research presents a new method to analyze the microstructure of wheat doughs and new understanding of how the network structure of the dough subunits contribute and are correlated with fundamental rheological tests.

The determination of aromatic compounds is of importance in many fields. Even if these compounds may be determined by molecular fluorescence and second-order calibration, the methods are relatively complex and require higher mathematics. Here is explored whether the reduction of the dimensions, i.e., transforming two-dimensional data to one-dimensional data followed by a special variable selection and calibration process, is feasible for this purpose. The present work investigated the feasibility of combining competitive adaptive reweighted sampling and elastic component regression for the direct evaluation of the spectra to quantify three components simultaneously. Model population analysis has also been performed. The results confirmed the feasibility of the procedure, which may serve as an alternative method to simultaneously determine aromatics.

Axisymmetric extrusion of an elasto-plastic material with the maximal shear stress condition between the material and the forming tool is considered. The elastic component of deformation is assumed negligible in comparison with its plastic part. Challenges related to the numerical modeling of such a problem with the commercial software ANSYS are identified. In conclusions, recommendations for treating the problem are proposed.

The deformational properties of Aramid fibers are subjected to a comparative analysis. It is shown that dividing processes involving the deformation of Aramid textiles into an elastic component and a viscoelastic-plastic component allows the proper choices to be made among materials which have certain elastic-mechanical properties. Comparative analysis of the viscoelastic characteristics of Aramid fibers is the foundation for solving the engineering problems encountered in the design and selection of materials having specified elastic and viscoelastic-plastic properties.

Foods may have both solid and liquid properties, and are described as viscoelastic products. Knowledge on such viscoelastic features is very useful for quality control and/or food stability. The purpose of this work was to evaluate the effect of the application of 1-MCP on the viscoelastic properties of minimally processed yellow pitahaya during refrigeration storage, by using a stress relaxation test. Viscoelastic parameters were determined through Generalized Maxwell and Peleg’s rheologic models. Both rheological models proved suitable to predict viscoelastic behavior; however, Peleg’s model better described this behavior. Samples of treated and non-treated pitahaya with 1- MCP decreased their elastic behavior (firmness decrease) during storage. Fruit treated with 1-MCP showed a greater elastic component than non-treated samples during storage. These two rheological models were suitable for predicting the viscoelastic behavior, however.

In reduced muscle preparations, stretch and muscle contraction change the properties of relaxed muscle fibres. In humans, effects of stretch and contraction on properties of relaxed muscles have been inferred from measurements of time taken to develop force, joint stiffness and reflex latencies. The current study used ultrasound imaging to directly observe the effects of stretch and contraction on muscle–tendon slack length and fascicle slack length of the human vastus lateralis muscle in vivo. The muscle was conditioned by (a) strong isometric contractions at long muscle–tendon lengths, (b) strong isometric contractions at short muscle–tendon lengths, (c) weak isometric contractions at long muscle–tendon lengths and (d) slow stretches. One minute after conditioning, ultrasound images were acquired from the relaxed muscle as it was slowly lengthened through its physiological range. The ultrasound image sequences were used to identify muscle–tendon slack angles and fascicle slack lengths. Contraction at short muscle–tendon lengths caused a mean 13.5 degree (95% CI 11.8–15.0 degree) shift in the muscle–tendon slack angle towards shorter muscle–tendon lengths, and a mean 5 mm (95% CI 2–8 mm) reduction in fascicle slack length, compared to the other conditions. A supplementary experiment showed the effect could be demonstrated if the muscle was conditioned by contraction at short lengths but not if the relaxed muscle was held at short lengths, confirming the role of muscle contraction. These observations imply that muscle contraction at short lengths causes the formation of bonds which reduce the effective length of structures that generate passive tension in muscles. KEY POINTS: In reduced muscle preparations, the slack length and passive stiffness of muscle fibres have been shown to be influenced by previous muscle contraction or stretch. In human muscles, such behaviours have been inferred from measures of muscle force, joint stiffness and reflex magnitudes and latencies. Using ultrasound imaging, we directly observed that isometric contraction of the vastus lateralis muscle at short lengths reduces the slack lengths of the muscle-tendon unit and muscle fascicles. The effect is apparent 60 s after the contraction. These observations imply that muscle contraction at short lengths causes the formation of bonds which reduce the effective length of structures that generate passive tension in muscles.ABSTRACT: In reduced muscle preparations, stretch and muscle contraction change the properties of relaxed muscle fibres. In humans, effects of stretch and contraction on properties of relaxed muscles have been inferred from measurements of time taken to develop force, joint stiffness and reflex latencies. The current study used ultrasound imaging to directly observe the effects of stretch and contraction on muscle-tendon slack length and fascicle slack length of the human vastus lateralis muscle in vivo. The muscle was conditioned by (a) strong isometric contractions at long muscle-tendon lengths, (b) strong isometric contractions at short muscle-tendon lengths, (c) weak isometric contractions at long muscle-tendon lengths and (d) slow stretches. One minute after conditioning, ultrasound images were acquired from the relaxed muscle as it was slowly lengthened through its physiological range. The ultrasound image sequences were used to identify muscle-tendon slack angles and fascicle slack lengths. Contraction at short muscle-tendon lengths caused a mean 13.5 degree (95% CI 11.8-15.0 degree) shift in the muscle-tendon slack angle towards shorter muscle-tendon lengths, and a mean 5 mm (95% CI 2-8 mm) reduction in fascicle slack length, compared to the other conditions. A supplementary experiment showed the effect could be demonstrated if the muscle was conditioned by contraction at short lengths but not if the relaxed muscle was held at short lengths, confirming the role of muscle contraction. These observations imply that muscle contraction at short lengths causes the formation of bonds which reduce the effective length of structures that generate passive tension in muscles.

Two types of ovine whey powder, with different protein content, were added at increasing substitution rates to two types of semolina, one with strong and tenacious gluten and the other with weak and sticky gluten. For each dough the optimum mixing time and hydration level were calculated using the consistograph. The whey powder negatively affected the leavening volume of all doughs, at all percentages except the lowest one (5%), mainly because of its effects on the elastic component of gluten as measured with a stress relaxation test. Differences of the secondary structure of gluten proteins among samples were investigated by analyzing the amide I band in the Fourier transform infrared spectra of the dough. Weak and strong semolina showed a different relative percentage of α-helix, random coil, and β-sheet structures. The longer mixing times for dough formation when using semolina with strong gluten led to an increase in α-helices and random coils, which caused a worse leavening performance than the weak-gluten semolina.

Objective:24-hour ambulatory pulse pressure (PP) is a powerful predictor of outcome. We attempted to apply the recently described PP components, an elastic (elPP), and systolic stiffening (stPP) components from 24-hour ambulatory blood pressure (BP) monitoring (AMBP), and examine their influence on

Cloud environments are being increasingly used for the deployment and execution of complex applications and particularly component-based ones. They are expected to provide elasticity, among other characteristics, in order to allow a deployed application to rapidly change the amount of its allocated resources in order to meet the variation in demand while ensuring a given Quality of Service (QoS). However, establishing a correct elastic component-based application is not guaranteed in Cloud. Indeed, applying elasticity mechanisms should preserve functional properties and improve non-functional properties related to QoS, performance and resource consumption. In this paper, we propose an approach for the verification and deployment of elastic component-based applications. Our approach is based on the Event-B formal method. In fact, we formally model the component artifacts using Event-B and we define the Event-B events that model the elasticity mechanisms (scaling up and down) for component-based applications. Furthermore, we formally verify that our approach preserves the semantics of the component-based applications by using the proof obligations and the ProB animator. Once the elastic component-based applications are validated, they can be deployed in a Cloud environment using an elastic deployment framework which we have developed.