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In the pole vault event, the velocity of approach is a highly vital factor. As velocity of approach improvements highly impact performance improvements. This study analysed the relationships between sprint running’s speed (SR), pole running (PR, without jump), and the pole vault approach (PVA, with real jump). Analysed too were the relationships between both the approach and performance’s respective running distance, velocity, and velocity utilization rates. Methods: Ten male pole vaulters were recruited. Measured was each 5-meter segment’s average velocity of his respective SR, PR, and PVA, along with the distance to maximum velocity. Results: The maximum average velocity of the PR’s 5m segments altogether was significantly positively correlated with pole vault (PV) performance; The maximum average velocity of the PR’s 5m segments altogether was significantly positively correlated with the last 5m PVA average velocity; The PVA velocity’s utilization rate was significantly negatively correlated with the difference between the distance to the PR’s maximum velocity and the PVA’s distance. Conclusion: The PR segment’s maximum speed capability can evaluate both a pole vaulter’s potential and pole vault-specific abilities. This study’s recruited pole vaulters’ respective approach distances were generally insufficient that resulted in a lower velocity utilization rate. Suggested is that in training, the pole vaulter could first find the distance required to reach the highest velocity upon starting from the PR test. Thus, this subsequently known distance could be applied in tandem with the pole vault’s approach to both improve the PVA’s utilization rate and reach the individual highest speed level.

Background Spinal trauma is common in polytrauma; spinal cord injury (SCI) is present in a subset of these patients. Penetrating SCI has been studied in the military; however, civilian SCI is less studied. Civilian injury pathophysiology varies given the generally lower velocity of the projectiles. We sought to investigate civilian penetrating SCI in the United States. Methods We queried the National Inpatient Sample for data regarding penetrating spinal cord injury from the past 10 years (2006–2015). The National Inpatient Sample includes data of 20% of discharged patients from U.S. hospitals. We analyzed trends of penetrating SCI regarding its diagnosis, demographics, surgical management, length of stay, and hospital costs. Results In the past 10 years the incidence of penetrating SCI in all SCI patients has remained stable with a mean of 5.5% (range 4.3%−6.6%). Of the patients with penetrating SCI, only 17% of them underwent a surgical procedure, compared with 55% for nonpenetrating SCI. Patients with penetrating SCI had a longer length of stay (average 23 days) compared with nonpenetrating SCI (15 days). Hospital charges were higher for penetrating SCI: $230,186 compared with $192,022 for closed SCI. Males patients were more affected by penetrating SCI, as well as black and Hispanic populations compared with whites. Conclusions Penetrating SCI represents 5.5% of all SCI patients. Men, blacks, and Hispanics are disproportionally more affected by penetrating SCI. Patients with penetrating SCI have fewer surgical interventions, but their overall length of stay and hospital costs are greater compared with nonpenetrating SCI.

Long-lasting insecticide-treated netting (LLIN) has begun to be used in agricultural product protection. We investigated the effect of a deltamethrin-incorporated LLIN on three stored product insects, red flour beetle, Tribolium castaneum (Herbst), lesser grain borer, Rhyzopertha dominica (F.), and rice weevil, Sitophilus oryzae (L.). Long-distance repellency was assessed in a wind tunnel for adults of each species, but no repellency was observed. Insect movement and behavior was assessed by observing the movement of adult beetles on treated and untreated netting during a 5 min period for distance traveled, velocity, mobility, and time on each netting type. Among all netting combinations, T. castaneum spent the most time highly mobile, higher velocity, and traveled a greater distance. Sitophilus oryzae and R. dominica spent significantly more time immobile and lower velocity. Efficacy of LLIN was tested by exposing adults for 60 min, removing, and holding with or without food, and monitoring for mortality up to 7 d. All S. oryzae and R. dominica were either affected or dead at all post-exposure times. The number of affected and dead adult T. castaneum combined 7 d after exposure was 42% and 95%, with or without food, respectively, and 52% of affected adults were able to recover when food was present. Overall, LLIN had no repellency or negative effect on insect movement, which increases the probability of lethal exposures of adults from walking on the netting. LLIN can be adopted in existing integrated pest management (IPM) programs for food processing facilities to prevent stored product insect infestations.

The Tournemire Underground Research Laboratory (Aveyron, France), developed by the French Institute for Radiological Protection and Nuclear Safety, is composed of a tunnel excavated in an argillaceous geological layer belonging to a limestone–argillite–limestone sub-horizontal sedimentary sequence. Sub-vertical fault zones are intercepted by drifts and boreholes excavated from the tunnel in the argillaceous layer at a depth of about 250 m. These fault zones are characterized by velocities lower than those of the embedding rocks. In this study, we assess the capacity of first arrival traveltime tomography to detect and characterize such fault zones in a surface-to-depth transmission configuration with a limited angle aperture. The source at the surface is a sledgehammer and turns out to be very repetitive. The source trigger is transmitted to the acquisition bay via a VHF transmitter. Receivers are located at depth in underground works. First arrivals are clear and traveltime picking is straightforward. Before inverting real data, we conduct synthetic tests with the real acquisition geometry to assess limits and validity of first arrival traveltime tomography to detect a lower velocity fault zone using different initial configurations and inversion constraints during the inversion. We show that introducing a priori information on velocities in the shallow subsurface, limestones and argillaceous layers and constraints on maximum velocities greatly helps improving results and subsequent interpretation. Velocities obtained from the real data display a main lower velocity zone that extends from the galleries in the argillaceous layer right up to the surface in limestones. The location and extension of this lower velocity zone are consistent with fault and fracture zones mapped from geological observations.

An important part in designing stepped spillways is making the spillway in order to direct the flow appropriately on the first step. In low discharges, the water flow moves over the spillway and arrives at the first step, and if the first step is high enough, the flow may leave the first step horizontally, skip some steps and land as a free jet of water on the lower steps, which might cause some damages to the structure. One of the solutions to this problem is to use CEDEX profile, transition steps between the ogee crest and the stepped chute. The present research carries out a numerical study of the effects of CEDEX profile on various hydraulic parameters and also the effects of the chute slope on the performance of this profile in preventing the flow jump. For this purpose, four models were created with different geometries and were studied in various discharges with FLOW-3D software. The results show that deploying CEDEX profile in the initial parts of the spillway leads to lower velocity and less risk of cavitation. Also, the results illustrate that CEDEX profile can shift the inception point of aeration to downstream. Furthermore, findings show that CEDEX profile, in the slope of less than 50°, can prevent flow jump in the first step. In steeper slopes, however, it fails to achieve the optimal performance.

The G4C2 hexanucleotide repeat expansion in the c9orf72 locus is one among a plethora of mutations associated with amyotrophic lateral sclerosis. It accounts for the majority of disease cases. The exact processes underlying the pathology of this mutation remain elusive, yet recent evidence suggests a mechanism that disrupts axonal trafficking. Here, we used a neuronal cell line with and without the G4C2 repeats, and implemented time-resolved local mean squared displacement analysis to characterize the motion of lysosomes inside neurites. Neurites were either aligned along chemically patterned lines, or oriented randomly on the substrate. We confirmed that in the presence of the G4C2 repeats, lysosome motion was affected. Lysosomes had a smaller reach exhibited lower velocity, especially inside aligned neurites. At the same time they became more active with increasing length of the G4C2 repeats when the neurites were randomly oriented. The duration of diffusive and super-diffusive lysosome transport remained unaffected for both neurite geometries and for all lengths of the repeats, but the displacement and velocity was decreased on varying the repeat number and neurite geometry. Lastly, the ratio of anterograde/retrograde/neutral trajectories was affected disparately for the two neurite geometries. Our observations support the hypothesis that impaired axonal trafficking emerges in the presence of the G4C2 hexanucleotide repeat expansion.

The heart is widely acknowledged as the unique driver of blood circulation. Recently, we discovered a flow-driving mechanism that can operate without imposed pressure, using infrared (IR) energy to propel flow. We considered the possibility that, by exploiting this mechanism, blood vessels, themselves, could propel flow. We verified the existence of this driving mechanism by using a three-day-old chick-embryo model. When the heart was stopped, blood continued to flow, albeit at a lower velocity. When IR was introduced, flow increased, by ∼300%. When IR energy was diminished under otherwise physiological conditions, blood failed to flow. Hence, this IR-dependent, vessel-based flow-driving mechanism may indeed operate in the circulatory system, complementing the action of the heart.

There is little research on the behavioral interaction between bicycle lanes and commercial vehicle loading zones (CVLZ) in the United States. These interactions are important to understand, to preempt increasing conflicts between truckers and bicyclists. In this study, a bicycling simulator experiment examined bicycle and truck interactions. The experiment was successfully completed by 48 participants. The bicycling simulator collected data regarding a participant's velocity and lateral position. Three independent variables reflecting common engineering approaches were included in this experiment: pavement marking (L1: white lane markings with no supplemental pavement color, termed white lane markings, L2: white lane markings with solid green pavement applied on the conflict area, termed solid green, and L3: white lane markings with dashed green pavement applied on the conflict area, termed dashed green), signage (L1: No sign and L2: a truck warning sign), and truck maneuver (L1: no truck in CVLZ, L2: truck parked in CVLZ, and L3: truck pulling out of CVLZ). The results showed that truck presence does have an effect on bicyclist's performance, and this effect varies based on the engineering and design treatments employed. Of the three independent variables, truck maneuvering had the greatest impact by decreasing mean bicyclist velocity and increasing mean lateral position. It was also observed that when a truck was present in a CVLZ, bicyclists had a lower velocity and lower divergence from right-edge of bike lane on solid green pavement, and a higher divergence from the right-edge of bike lane was observed when a warning sign was present.

In the present paper, a theory-based advancement of the car following model of Wiedemann is introduced. It is suitable for a more realistic simulation of human longitudinal guidance behaviour in the lower velocity range, like in urban traffic. The algorithm was identified and developed by means of a driving simulator study, which is introduced as well. While the decision making process in recent car following models based on Wiedemann is solely determined by the time headway to the leading vehicle, the results of the study show that information about time to collision is also used in the lower velocity range. This approach delivers a more realistic simulation of human car following behaviour, which can be integrated into driver models for microscopic traffic simulations and for the control of surrounding traffic in driving simulators.

A high-precision calibration system for laser Doppler velocimeter (LDV) is designed to calibrate the reference-beam LDV. Larger velocity range, lower velocity uncertainty and smaller alignment error can be provided in calibration process by employing a rotary cylinder with 600 mm radius in the calibration system. Experiments are carried out for detailed analysis. The results show that the relative measurement precision of the LDV under calibration is 0.1% (1σ) in the velocity range from 0 to 200 km/h. The main sources of uncertainty in the calibration system are discussed. The expanded uncertainty of the proposed system is 0.03%. The proposed calibrating method can be used in the calibration process for the reference-beam LDV, the dual-beam differential LDV, the self-mixing LDV and the spatial filtering velocimeter.

In this work we investigate the influence of the dynamic state of galaxy clusters on segregation effects and velocity dispersion profiles (VDPs) for a sample of 111 clusters extracted from SDSS-DR7. We find that 73 clusters have Gaussian (G) velocity distribution and 38 clusters have a complex or non-Gaussian (NG) velocity distribution. We also split the G and NG samples into 'active' and 'passive' galaxies, according to their sSFRs and stellar masses. Our results indicate a strong spatial segregation between active and passive galaxies both in G and NG systems, with passive galaxies being more central. We also found that the passive population in G systems is the only family with lower velocity dispersions for the brightest galaxies ($M_r \lesssim -22.75$), thus presenting velocity segregation with luminosity. The similarity found between the VDPs of the galaxy populations in NG systems indicate that these sets probably share a similar mix of orbits. We also found a clear evolutionary trend for G systems, with brighter galaxies in richer clusters having flatter VDPs. The scenario emerging from this study suggests a direct relationship between segregation effects, VDPs and the dynamic state of clusters., Accepted for publication in MNRAS. 6 pages, 3 figures

Groundwater is important for daily life, because it is the largest freshwater source for domestic use and industrial consumption. Sustainable groundwater depends on many parameters: climate change is one factor, which leads to floods and droughts. Distribution of groundwater age indicates groundwater velocity, recharge rate and risk assessment. We developed transient 3D mathematical models, i.e., MODFLOW and MODPATH, to measure the distributions of groundwater age, impacted by climate change (IPSL-CM5A-MR), based on representative concentration pathways, defined in terms of atmospheric CO2 concentration, e.g., 2.6 to 8.5, for the periods 2020 to 2099. The distributions of groundwater age varied from 100 to 100,000 years, with the mean groundwater age ~11,000 years, generated by climate led change in recharge to and pumping from the groundwater. Interestingly, under increasing recharge scenarios, the mean age, in the groundwater age distribution, decreased slightly in the shallow aquifers, but increased in deep aquifers, indicating that the new water was in shallow aquifers. On the other hand, under decreasing recharge scenarios, groundwater age increased significantly, both shallow and deep aquifers, because the decrease in recharge caused longer residence times and lower velocity flows. However, the overall mean groundwater age gradually increased, because the groundwater mixed in both shallow and deep aquifers. Decreased recharge, in simulation, led to increased groundwater age, thus groundwater may become a nonrenewable groundwater. Nonrenewable groundwater should be carefully managed, because, if old groundwater is pumped, it cannot be restored, with a detriment to human life.

It has been demonstrated that Kinesio Tape (KT) application has immediate positive effects on balance in healthy individuals, but its mid-term effects have not yet been investigated.Evaluate the effects of KT on postural control in young women, using four strategies.Forty-eight healthy women aged 18-35 years old were randomly assigned to four groups with different elastic bandages (G1: ankle; G2: hamstrings; G3: lumbar; G4: different taping applications) and their postural control was evaluated using stabilographic parameters obtained on a force platform during right and left unipodal (UNP-R and UNP-L) and semi-tamdem tests at pre-intervention (PRE), immediately after (IME), and 24 and 48 h after the application of bandages.G1 showed a significantly lower velocity in the antero-posterior direction for the PRE compared to the IME period (p = 0.0204) in the UNP-R task, and the same was observed in the medio-lateral velocity when comparing the results for PRE with IME (p = 0.0340 and p = 0.0244) in the UNP-L task. Regarding the frequency, G2 had a significantly lower mean for the PRE, compared to IME (p 0.001) in the UNP-R in antero-posterior direction, and in medio-lateral direction in the UNP-R (p = 0.003) and in the UNP-L task (p = 0.020).The use of KT changed postural control, mainly considering the velocity and frequency of COP oscillations, and especially immediately after its application.

Past Suzaku, XMM and NuSTAR observations of the nearby (z=0.0323) bright Seyfert 2 galaxy MCG-03-58-007 revealed the presence of two deep and blue-shifted Fe K-shell absorption line profiles. These could be explained with the presence of two phases of a highly ionized, high column density accretion disk wind outflowing with $v_{out1}\sim -0.1c$ and $v_{out2}\sim -0.2c$. Here we present two new observations of MCG-03-58-007: one was carried out in 2016 with Chandra and one in 2018 with Swift. Both caught MCG-03-58-007 in a brighter state ($F_{\mathrm{2-10\,keV}}\sim 4\times 10^{-12}$ erg cm$^{-2}$ s$^{-1}$) confirming the presence of the fast disk wind. The multi-epoch observations of MCG-03-58-007 covering the period from 2010 to 2018 were then analysed. These data show that the lower velocity component outflowing with $v_{out1}\sim -0.072\pm 0.002c$ is persistent and detected in all the observations, although it is variable in column density in the range $N_\rm{H}\sim 3-8 \times 10^{23}$cm$^{-2}$. In the 2016 Swift observation we detected again the second faster component outflowing with $v_{out2}\sim -0.2c$, with a column density ($N_\rm{H}=7.0^{+5.6}_{-4.1}\times 10^{23}$cm$^{-2}$), similar to that seen during the Suzaku observation. However during the Chandra observation two years earlier, this zone was not present ($N_\rm{H}, 10 pages, 5 figures, 3 tables, accepted by MNRAS

Throughfall erosivity is necessary for the prediction of soil erosion in some forests with little protective ground cover. Throughfall drops and erosivity were compared with open rainfall and at four different crown positions beneath the canopy in a teak plantation in Thailand. Throughfall was partitioned into free throughfall, splash throughfall, and canopy drip using drop size distributions of both open rainfall and throughfall. Compared with open rainfall, (1) throughfall drops were lower in number but larger in size due to the coalescence of raindrops on canopies; (2) throughfall drops, especially canopy drip, had lower velocity due to insufficient fall distance from the canopy to the forest floor to reach terminal velocity, which partly depends on crown base height and the vertical distribution of foliage; and (3) throughfall usually had higher kinetic energy due to larger drop size, which depends on the amount of canopy drip and the crown base height. Throughfall kinetic energy was higher in mid-crown positions than in the gap or near-stem positions. Compared to mid-crown positions, the gap position had smaller drops and less canopy drip, while the near-stem position had lower drop fall velocity. The erosivity of throughfall with respect to crown position is useful to better understand canopy–water–soil interactions, develop high-resolution maps of potential soil erosion risk, and help maintain forest productivity.

An extended floor field model was proposed to investigate evacuation behaviors of pedestrians under the threat of artificial attack. In this model, pedestrian movement governed by the static and dynamic floor field, and the motion and assault of artificial attacker were involved simultaneously. Further, injuries with lower velocity and deaths of pedestrians caused by the attacker during evacuation were considered. And a new parameter k t was introduced. It is the sensitivity coefficient of attack threat floor field and could reflect quantitatively the extent of effect of attack threat on the decision-making of the individual. Moreover, effects of several key parameters such as the sensitivity coefficient, assault intensity and pedestrian density on evacuation dynamics were studied. Results show that pedestrian evacuation would display interesting phenomena transiting from rolling behavior to along-the-wall motion with aggravating extent of the impact of attackers on pedestrians, which refers k t in the model varying from 0.5 to 0.8. As assault intensity increases, more casualties would be caused and the available evacuation time would decrease, which means people have to flee the room in a shorter time period for survival. When the pedestrian density increases, more clogging at the exit would be generated and pedestrians would be more difficult to evacuate due to the limited capacity of egress and the reduction in the average speed of pedestrian flow caused by the injured. And the injured with limited motion capacity could hardly complete the evacuation owing to that they need more evacuation time and would retard the speed of the pedestrian flow.

In order to investigate the interaction between double spherical tungsten fragments and Composition B (Comp B) covered by tantalum coverplates, the numerical simulation was carried out by using AUTODYN-3D software. The influence on the shock initiation characteristics of double fragments at various distance separation b1, time separation h1, impact angle α with the same or different velocities were analyzed, and the critical initiation velocity of covered Comp B was obtained. The obtained simulation results show that, under certain circumstances, the superposition effect of shock waves caused by double fragments impact on covered Comp B is obvious. The critical initiation velocity increases with the increase of b1 when fragments impacting on covered charge at the same time with same or different velocities, with α=0, and approaches critical velocity of a single fragment. The critical initiation velocity decreases initially and then increases with the increase of h1 when fragments impacting asynchronously on covered charge with different velocities and α=0. When fragments impacting synchronously on covered Comp B with different velocities, the critical velocity decreases initially and then increases with the increase of α. When fragments impacting asynchronously on covered Comp B with different velocities, the critical velocity increases with the increase of h1. Therefore, a shock initiation of covered Comp B rather be achieved by multiple fragments at lower velocity than by a single fragment at higher.

Modern urinary catheter-to-leg-bag systems suffer from a number of shortcomings. Drainage tubing of current urinary leg bags is perceived as unnecessarily bulky compared to the indwelling catheters to which it is connected, and catheter designs are prone to the formation of biofilms, leading ultimately to encrustation and blocking. We used analytical and experimental engineering methodologies, aligned with current international (International Standards Organisation) and European standards, to optimise drainage tube size and flow efficiency and characterise tube kinking behaviour. Using computational fluid dynamics, we studied the influence of modern Foley catheter design on urodynamics and explored its potential influence on biofilm formation and encrustation. Results indicate that tubing diameters could be reduced by 40%-50% and still satisfy current International Standards Organisation flow rate standards for leg bags; this might also reduce the likelihood of tube kinking. The computational study showed how current catheter design may promote the development of lower velocity recirculating flows and high shear in proximity of regions known to be affected by bacterial adhesion and biofilm formation. If confirmed, these findings will give manufacturers greater flexibility to develop less obtrusive and more encrustation-resistant products for end users.

In case of fire, constructive features of typical atria could favor the spread of smoke. This makes the design of their smoke control and management systems a challenging task. Five full-scale fire experiments in the literature have been analyzed and numerically compared in FDS v6 to explore the influence of the make-up air. However, these fire experiments cover only a limited number of set-ups and conditions, and require further numerical modeling to obtain a deeper understanding of the makeup air influence. Subsequently, 84 simulations with FDS v6 have been carried out, considering different vent areas (air velocity from 0.4 to 5.3 m/s) and configurations, two heat release rates (2.5 and 5 MW), and two pan locations. It is demonstrated that make-up air velocities lower than the prescribed limit of 1 m/s, by the international codes, may induce adverse conditions. Based on our results, we recommended fire engineers to numerically assess the fire scenario with even lower velocity values. The results also show that asymmetric configurations are prone to induce circulation around the flame which can contribute to the formation of longer flames and fire whirls. Thus, this numerical study links two fire types allowing the connection of pool fires to fire whirls, which completely differ in behaviour and smoke filling, for the sake of design of fire safety.

The aim of this study was to determine the effect of vascularized fibula free flap (VFFF) harvest on gait variables during the six-minute walk test (6MWT). Eleven patients who had undergone VFFF harvest and 11 healthy peers participated in this case-control study. The main evaluation consisted of the collection of gait variables using the GAITRite system during three periods of the 6MWT: beginning (0-1min), middle (2:30-3:30min), and end (5-6min). The 6MWT was significantly shorter in the VFFF group than in the reference group (-31%, P

Salamanders use the hyobranchial apparatus and its associated musculature for tongue projection on land and for suction feeding in water. Hyobranchial apparatus composition and morphology vary across species, and different morphologies are better suited for feeding in aquatic versus terrestrial environments. We hypothesize that differences in hyobranchial morphology result in functional trade-offs in feeding performance. We predict that semi-aquatic and aquatic salamandrids with hyobranchial morphology suited for aquatic feeding will have lower performance, in terms of tongue-projection distance, velocity, acceleration and power, compared with terrestrial salamandrids when feeding in a terrestrial environment. We found that semi-aquatic and aquatic newts had lower velocity, acceleration and muscle-mass-specific power of tongue projection when compared with the terrestrial salamanders Chioglossa lusitanica and Salamandra salamandra. The fully aquatic newt, Paramesotriton labiatus, has a robust, heavily mineralized hyobranchial apparatus and was unable to project its tongue during terrestrial feeding, and instead exhibited suction-feeding movements better suited for aquatic feeding. Conversely, terrestrial species have slender, cartilaginous hyobranchial apparatus and enlarged tongue pads that coincided with greater tongue-projection distance, velocity, acceleration and power. Chioglossa lusitanica exhibited extreme tongue-projection performance, similar to that seen in elastically projecting plethodontid salamanders; muscle-mass-specific power of tongue projection exceeded 2200 W kg−1, more than 350 times that of the next highest performer, S. salamandra, which reached 6.3 W kg−1. These findings reveal that two fully terrestrial salamandrids have morphological specializations that yield greater tongue-projection performance compared with species that naturally feed in both aquatic and terrestrial environments.

With the extensive construction of rail tunnels, the subway has gradually become the most widely used means of public transport. As important transportation hubs, the evacuation capacity of subway stations is especially significant. An accurate prediction model can efficiently reduce the evacuation time, and the social force (SF) model is one of the most widely used evacuation models. Almost all past research based on the SF model has focused on a single model for pedestrians. However, in this research, based on different force models, a crowd is divided into three categories that have different kinds of movement based on different force models. The first category of pedestrians, namely luggage-laden pedestrians, is characterized by a lower velocity and large radii. The second category of pedestrians is ordinary pedestrians. The final category of pedestrians comprises panic pedestrians, who choose an angle at which to overtake the pedestrians in front of them. Simulations are performed based on different proportions of these three categories of pedestrians, and it is found that with the increase of the proportions of luggage-laden and panic pedestrians, the evacuation time is also increased; this phenomenon could not be observed with the original SF model. The performance of the modified SF model is then tested in a passage with a bottleneck, and it is found that the interaction between panic pedestrians and luggage-laden pedestrians greatly increases the difficulty of evacuation. The number of luggage-laden pedestrians is found to be the controllable factor that leads to an increase of the evacuation time at the evacuation bottlenecks. Therefore, solutions like warning signs at evacuation bottlenecks should be implemented.

We study the frictional and viscous effects on earthquake nucleation, especially for the nucleation phase, based on a one-degree-of-freedom spring-slider model with friction and viscosity. The frictional and viscous effects are specified by the characteristic displacement, U c, and viscosity coefficient, η, respectively. Simulation results show that friction and viscosity can both lengthen the natural period of the system and viscosity increases the duration time of motion of the slider. Higher viscosity causes a smaller amplitude of lower velocity motion than lower viscosity. A change of either U c (under large η) or η (under large U c) from a large value (U ch for U c and η h for η) to a small one (U cl for U c and η l for η) in two stages during sliding can result in a clear nucleation phase prior to the P-wave. The differences δU c = U ch − U cl and δη = η h − η l are two important factors in producing a nucleation phase. The difference between the nucleation phase and the P-wave increases with either δU c or δη. Like seismic observations, the peak amplitude of P-wave, which is associated with the earthquake magnitude, is independent upon the duration time of nucleation phase. A mechanism specified with a change of either η or U c from a larger value to a smaller one due to temporal variations in pore fluid pressure and temperature in the fault zone based on radiation efficiency is proposed to explain the simulation results and observations.

This study investigated the stick-slip characteristics of a magneto-rheological elastomer (MRE) against an aluminum plate. Herein, the MRE was manufactured, and a stick-slip tester was employed to evaluate the stick-slip performance of the MRE under different velocities and load conditions with and without a magnetic field. The fast Fourier transform (FFT) of the friction force of the stick-slip and the roughness of the aluminum plate surface were calculated to confirm the stick-slip phenomenon. After the tests, the wear surfaces were observed to evaluate the wear properties of the MRE regarding the stick-slip. Results showed that the stick-slip was smaller at lower velocity. At higher velocity, the reduction of the stick-slip under a magnetic field was more clearly observed. Moreover, the wear reduced with reduced stick-slip under a magnetic field.

Thin layers – regions where plankton or particles accumulate vertically on scales of a few meters or less – are common in coastal waters, and have important implications for both trophic dynamics and carbon cycling. These features can form by a variety of biological and physical mechanisms, including localized growth, shear-thinning, and directed swimming. An additional mechanism may result in the formation of thin layers of marine aggregates, which have been shown to decrease their settling velocity when passing through sharp density gradients, a behavior termed delayed settling. Here, we apply a simple vertical advection-diffusion model to predict the properties of aggregate thin layers formed by this process. We assume a constant vertical flux of particles from the surface, which is parameterized by observations from laboratory experiments with marine aggregates. The formation, maintenance, and shape of the layers are described in relation to non-dimensional numbers that depend on environmental conditions and particle settling properties. In particular, model results demonstrate layer intensity and sharpness both increase with higher Peclet number ( Pe ), that is, under conditions with weaker mixing relative to layer formation. Similarly, more intense and sharper layers are found when the delayed settling behavior of aggregates is characterized by a lower velocity minimum. The model also predicts layers that are vertically asymmetric and highly “peaky” when compared with a Gaussian distribution, features often seen in thin layers in natural environments. Lastly, by comparing model predictions with observations of thin layers in the field, we are able to gain some insight into the applicability of delayed settling as a thin layer formation mechanism in different environmental conditions.

In this paper, the dynamic crack-interface interactions and the related mechanics of crack penetration vs. branching at a weak interface are studied experimentally. The interface is oriented perpendicular to the incoming mode-I crack in an otherwise homogeneous bilayer. The focus of this investigation is on the effect of interface location and the associated crack-tip parameters within the bilayer on the mechanics of the ensuing fracture behavior based on the optical methodologies laid down in Ref. Sundaram and Tippur (2016). Time-resolved optical measurement of crack-tip deformations, velocity and stress intensity factor histories in different bilayer configurations is performed using Digital Gradient Sensing (DGS) technique in conjunction with high-speed photography. The results show that the crack path selection at the interface and subsequently the second layer are greatly affected by the location of the interface within the geometry. Using optically measured fracture parameters, the mechanics of crack penetration and branching are explained. Counter to the intuition, a dynamically growing mode-I approaching a weak interface at a lower velocity and stress intensity factor penetrates the interface whereas a higher velocity and stress intensity factor counterpart gets trapped by the interface producing branched daughter cracks until they kink out into the next layer. An interesting empirical observation based on measured crack-tip parameters for crack penetration and branching is also made.

Handwriting is a human activity that may be affected by the modality used as input of the information to be written, mainly copying or dictation. Many processes at different levels are involved to produce motor planning and graphomotor automation of handwriting. In order to quantify possible kinematic differences due to the influence of auditory or visual input modalities to these processes, three different tests were proposed to a sample of 101 young students and several kinematics parameters measuring handwriting characteristics were evaluated. The tests required to copy as accurate (CA) and as fast (CF) as possible an Italian sentence and to write the same sentence under dictation (DF). All parameters showed significant differences between each pair of the three tests. The best performance was obtained in the CF test followed by the DF and CA tests; in the latter the greater accuracy required to produce writing yielded lower velocity and automation as well as a longer motor planning time. On the other hand, the dictation response was more similar to that of CF than CA showing a larger planning time, probably due to a different time necessary to correctly identify the words to reproduce. The combination of the two tests could be useful to study the impairment of either visual or auditory input.

During more than one decade of studying initiation phenomenology numerous papers were published by the authors. A multitude of experimental data on hypervelocity impact initiation of plastic bonded high explosive charges by shaped charge jets (SCJ) and some data in the ordnance velocity impact regime obtained with STANAG projectiles and explosively formed projectiles (EFP) were generated. Amongst other findings the results showed that the established assumption that the critical stimulus is constant was wrong and that a new initiation model is needed taking the new results into account. Towards such a new model further investigation was necessary trying to make a link between the initiation phenomenology of shaped charge jet impacts in the hypervelocity regime and of projectile impacts in the lower velocity regime. To bridge the existing data gap a new approach was taken applying newly designed “simplified shaped charges” (SSC). This paper describes the way to this new approach and summarizes the related test results as well as their implications.

This study aimed to investigate the effects of handedness on motion accuracies and to compare 3D kinematic data in reaching performance of dominant and non-dominant hand with the influence of movement speed and target locations. Twelve healthy young adults used self-selected and fast speed to reach for three different target locations as follows: frontal, ipsilateral and contralateral to the performing hand, with equal distance. Both hands were tested and kinematic parameters were recorded by 3D motion analysis system. Successful rate, reach path ratio, mean and peak velocity, the timing of peak velocity and ROM of joints were analyzed. Reach path ratio was smaller when using the dominant hand (p < 0.01) and fast speed (p < 0.01) to perform the movement, but the successful rate of the dominant hand was lower than non-dominant hand during fast speed reaching (99.1% vs 100%). Contralateral movement had lower velocity than the other two target locations, while velocity did not vary between non-dominant and dominant hand. The timing of peak velocity occurred significantly later for fast speed movements (p < 0.01). Trunk rotation was significantly smaller when using the dominant hand, fast movement speed or reaching to the ipsilateral target. The ROM of elbow and wrist flexion-extension decreased in contralateral reaching. The performance of the dominant hand and/or fast speed movements was more efficient with straighter hand path and less trunk rotation, but the successful rate decreased in dominant hand during fast speed movements. The timing of peak velocity occurred later during fast movement in both hands indicating a decreased feedback phase. Target location can influence movement strategy as reaching to contralateral target required more proximal movements and ipsilateral reaching used more distal segment movements.

The aim of this study was to compare the time course of recovery following four different resistance exercise protocols in terms of loading magnitude (60% vs. 80% 1RM&mdash, one-repetition maximum) and velocity loss in the set (20% vs. 40%). Seventeen males performed four different protocols in full squat exercise, which were as follows: (1) 60% 1RM with a velocity loss of 20% (60-20), (2) 60% 1RM with a velocity loss of 40% (60-40), (3) 80% 1RM with a velocity loss of 20% (80-20), and (4) 80% 1RM with a velocity loss of 40% (80-40). Movement velocity against the load that elicited a 1 m&middot, s&minus, 1 velocity at baseline measurements (V1-load), countermovement jump (CMJ) height, and sprint time at 20 m (T20) were assessed at Pre, Post, 6 h-Post, 24 h-Post, and 48 h-Post. Impairments in V1-load were significantly higher for 60-40 than other protocols at Post (p &lt, 0.05). The 60-20 and 80-40 protocols exhibited significant performance impairments for V1-load at 6 h-Post and 24 h-Post, respectively (p &lt, 0.05). CMJ height remained decreased for 60-20 and 60-40 until 24 h-Post (p &lt, 0.001&ndash, 0.05). Regarding T20, the 80-40 protocol resulted in higher performance than 60-40 at 24 h-Post and the 80-20 protocol induced a greater performance than 60-40 protocol at 48 h-Post (p &lt, 0.05). A higher velocity loss during the set (40%) and a lower relative load (60% 1RM) resulted in greater fatigue and slower rate of recovery than lower velocity loss (20%) and higher relative load (80% 1RM).

Relative humidity (RH) at the body-seat interface is considered an important factor in both sitting comfort and generation of health concerns such as skin lesions. Technical difficulties appear to have limited research aimed at the detailed and simultaneous exploration of RH and temperature changes at the body-seat interface, using RH sensors without the capability to record temperature where RH is recorded. To explore the causes of a spike in RH consistently produced on first contact between body and seat surface, we report data from the first use of dual temperature and RH (HTU21D) sensors in this interface. Following evaluation of sensor performance, the effect of local thermal changes on RH was investigated. The expected strong negative correlation between temperature and RH (R2 = &minus, 0.94) supported the importance of considering both parameters when studying impact of sitting on skin health. The influence of sensor movement speed (higher velocity approach: 0.32 cm/s &plusmn, 0.01 cm/s, lower velocity approach: 0.17 cm/s &plusmn, 0.01 cm/s) into a static RH region associated with a higher local temperature were compared with data gathered by altering the rate of a person sitting. In all cases, the faster sitting down (or equivalent) generated larger RH outcomes: e.g., in human sitting 53.7% &plusmn, 3.3% RH (left mid-thigh), 56.4% &plusmn, 5.1% RH (right mid-thigh) and 53.2% &plusmn, 2.7% RH (Coccyx). Differences in size of RH change were seen across the measurement locations used to study the body-seat interface. The initial sitting contact induces a transient RH response (duration &le, 40 s) that does not accurately reflect the microenvironment at the body-seat interface. It is likely that any movement during sitting would result in similar artefact formation. As a result, caution should be taken when investigating RH performance at any enclosed interface when the surfaces may have different temperatures and movement may occur.

Alfv\'enic fluctuations are very common features in the solar wind and are found especially within the main portion of fast wind streams while the slow wind usually is less Alfv\'enic and more variable. In general, fast and slow wind show many differences which span from the large scale structure to small scale phenomena including also a different turbulent behaviour. Recent studies, however, have shown that even slow wind can be sometimes highly Alfv\'enic with fluctuations as large as those of the fast wind. The present study is devoted to present many facets of this Alfv\'enic slow solar wind including for example the study of the source regions and their connection to coronal structures, large-scale properties and micro-scale phenomena and also impact on the spectral features. This study will be conducted performing a comparative analysis with the typical slow wind and with the fast wind. It has been found that the fast wind and the Alfv\'enic slow wind share common characteristics, probably attributable to their similar solar origin, i.e. coronal-hole solar wind. Given these similarities, it is suggested that in the Alfv\'enic slow wind a major role is played by the super-radial expansion responsible for the lower velocity. Relevant implications of these new findings for the upcoming Solar Orbiter and Solar Probe Plus missions, and more in general for turbulence measurements close to the Sun, will be discussed.

The presented work describes the hydrodynamic assessment studies of a much needed technical innovation of Sea Based Container Culture (SBCC) as part of a semi-intensive, passive aquaculture culture system for farming the European lobster ( Homarus gammarus ). Factors that are known to influence growth and survival rates were obtained from previous literature, including flow rate, wave energy and motion characteristics; these factors defined performance criteria for SBCC containers. The internal flow velocities and external flow patterns for different SBCC container designs were measured and used to inform design decisions. Suitable graphical representations have been developed to assess SBCC containers on specific performance criteria. Oyster SBCC containers were found to provide stable motion characteristics but perform poorly against the lower velocity limit, indicating insufficient supply of Dissolved Oxygen (DO) to allow for optimal growth of European lobsters. Internal flow velocities were also measured on un-fouled and fouled SBCC containers; results showed SBCC 2 would not provide enough DO with 66% biofouling coverage (66% biofouling replicates one year deployment) and triggered a redesign. SBCC 1 at 90° yaw angle of attack demonstrated all round good performance against upper and lower velocity limits and motion characteristics; thus showed greatest promise for cultivation of European Lobster.

To evaluate the flow imaging capabilities of a new prototype ultrasound (US) image processing technique (superb micro-vascular imaging [SMI]; Toshiba Medical Systems, Tokyo, Japan) for depiction of microvascular flow in normal thyroid tissue and thyroid nodules compared with standard color and power Doppler US imaging.Ten healthy volunteers and 22 patients, with a total of 25 thyroid nodules, scheduled for US-guided fine needle aspiration were enrolled in this prospective study. Subjects underwent US examination consisting of grayscale, color and power Doppler imaging (CDI and PDI) followed by color and monochrome SMI and pulsed Doppler. SMI is a novel, microvascular flow imaging mode implemented on the Aplio 500 US system (Toshiba). SMI uses advanced clutter suppression to extract flow signals from large to small vessels and depicts this information at high frame rates as a color overlay image or as a monochrome map of flow. Two radiologists independently scored still images and digital clips for overall flow detection, vessel branching details and noise on a visual-analog scale of 1 (worst) to 10 (best).For the volunteers SMI visualized microvasculature with significantly lower velocity than CDI and PDI (P < 0.012). In all thyroid nodules, SMI demonstrated microvascular flow with significantly higher image scores and provided better depiction of the vessel branching details compared with CDI and PDI (P < 0.0001). Clutter noise was significantly higher in monochrome SMI mode than in the other modes, including color SMI (P < 0.001).The novel SMI mode consistently improved the depiction of thyroid microvascular flow compared with standard CDI and PDI.

In a driving simulator study, driving behaviour responses (speed and deceleration) to encountering a moose, automatic speed camera, wildlife warning sign and radio message, with or without a wildlife fence and in dense forest or open landscape, were analysed. The study consisted of a factorial experiment that examined responses to factors singly and in combination over 9-km road stretches driven eight times by 25 participants (10 men, 15 women). The aims were to: determine the most effective animal-vehicle collision (AVC) countermeasures in reducing vehicle speed and test whether these are more effective in combination for reducing vehicle speed; identify the most effective countermeasures on encountering moose; and determine whether the driving responses to AVC countermeasures are affected by the presence of wildlife fences and landscape characteristics. The AVC countermeasures that proved most effective in reducing vehicle speed were a wildlife warning sign and radio message, while automatic speed cameras had a speed-increasing effect. There were no statistically significant interactions between different countermeasures and moose encounters. However, there was a tendency for a stronger speed-reducing effect from the radio message warning and from a combination of a radio message and wildlife warning sign in velocity profiles covering longer driving distances than the statistical tests. Encountering a moose during the drive had the overall strongest speed-reducing effect and gave the strongest deceleration, indicating that moose decoys or moose artwork might be useful as speed-reducing countermeasures. Furthermore, drivers reduced speed earlier on encountering a moose in open landscape and had lower velocity when driving past it. The presence of a wildlife fence on encountering the moose resulted in smaller deceleration.

The ballistic performance of an Al alloy AA7020-T651 (AlZn4.5Mg1, 3.4335) against fragment-simulating projectiles (FSPs) is investigated at impact velocities between 900 m/s and 1500 m/s. The target plates are considered as thick regarding the ratio between the specimen thickness (40 mm) and the projectile diameter (20 mm). With increasing impact velocities, the observed failure modes of the target plates change from plugging to discing. The stress state leading to the discing formation has been described and numerically modeled by the Lagrangian approach. In order to understand the mechanisms that occur in the material under highly dynamic loadings, its mechanical, thermal and micro-structural properties are discussed. The experimental conditions (thick target, penetrator of a specific shape, high-velocity impacts) allow the authors to draw conclusions, which are complementary to those that resulted from investigations of semi-thick and thin target plates under ballistic impacts in a lower velocity range.

Due to its significance in oil recovery and droplet microfluidics, breakup of spherical droplets in a constriction (i.e., snap-off) is extensively studied. However, rectangular channels with large aspect ratios are commonly used in real applications, in which droplets usually present pancake shape. Since capillary pressures governing droplet’s snap-off depend strongly on droplet shape, we hypothesize that pancake droplets may exhibit different snap-off behaviors from spherical droplets. Via microfluidic experiments, we demonstrate that pancake droplets indeed present new snap-off behaviors in three aspects: (1) they snap off at high capillary numbers; (2) the interface breaks up at the rear meniscus instead of the front one; (3) the size of daughter droplets is dependent of mother droplet size instead of independent for spherical droplets. Besides, we reveal the underlying mechanism, i.e., pancake droplets show much lower velocity in the constriction than spherical droplets, via analyzing capillary pressures at the droplet’s two ends.

A newly synthesized SiC-graphite composite material was tested against a conventional martensitic stainless steel to evaluate its tribological properties through dry sliding using a pin on disc equipment. The tests were conducted at two velocities of 1.57 m/s and 7 m/s and a constant pressure of 0.5 MPa. The working temperature ranged from room temperature to higher temperatures of 100, 200, 250, 300 up to 400 °C. The friction coefficient increased with increase in temperature for tests conducted at the lower velocity. Conversely, the COF decreased with increase in temperature for high velocity testing condition. When the pin wear was considered, a severe wear was observed for all tests conducted at 1.57 m/s when compared to trials at 7 m/s, where the wear was characterized by mild wear. The analysis of the pin surface revealed that as and when the friction layer was smooth, compact and continuous, the pin wear would appreciably decrease. A bedding procedure was then proposed to attain mild wear even at 1.57 m/s.

The media geometry design is a parameter that influences the efficiency of PCO device for indoor air treatment. However, there is little information in the literature to show how it impacts degradation efficiency. In this work, media geometry influence on the degradation of acrylonitrile is investigated experimentally and with numerical simulations. The experiments were conducted in a laboratory closed loop multi-pass reactor with the aim of comparing degradation efficiencies using plane and pleated media geometries. The experimental results showed a higher removal efficiency for the pleated media. Numerical simulations provided some information to better connect the increase in efficiency to the change in media geometry considering and modeling the media as a porous zone. The simulation results showed that pollutants had lower velocity in pleated media thus contact time was increased by 76%. Additionally, the more heterogeneous distribution of velocity and irradiance in the pleated media could counteract the influence of the contact time and possibly explain the lower than expected experimental results.

Mg-Al layered double hydroxides (LDHs) were applied to soils to control phosphorus (P) loss. Column experiments were conducted with soil and LDHs under saturated conditions to investigate the retention and release of P with various LDHs dosages, flow velocity, and pH. The P retention and retardation of P breakthrough in soil with LDHs were enhanced with increasing LDHs dosages and pH as well as with decreasing flow velocity. The retention of P was successfully analyzed using a two kinetic sites model that accounted for irreversible and reversible retentions. Increasing LDHs dosages, decreasing flow velocity, and increasing pH bring greater maximum retained concentration on the solid phases (Smax1, i.e. irreversible retention) for P in LDHs-soil system. For reversible retention, the greater release rate from site 2 (k2d) than first-order retention rate coefficient on site 2 (k2) for most experiments reflects a rapid release process and near equilibrium transport behavior of P in LDHs-soil system. It is worth noting that the change of soil pH (8–5) and Darcy velocity (0.17–0.65 cm min−1) has little influence on the release of P from soil mixing with LDHs. The stability of LDHs in soil increases with greater LDHs dosages, higher pH, and lower velocity.

In order to reveal the effects of nanoparticle type on breakdown and prebreakdown characteristics, this paper presents an experimental study on the effects of conductive Fe 3 O 4 nanoparticles, semi-conductive TiO 2 nanoparticles and insulating Al 2 O 3 nanoparticles on the breakdown strength and prebreakdown streamer propagation in transformer oil under positive lightning impulse voltage. Nanoparticle with the same size, modifier and concentration are prepared. The results indicate that the type of nanoparticles has a notably effect on breakdown voltage of transformer oil. Positive breakdown voltage of Fe 3 O 4 nanofluid is markedly increased by 41.3% compared to that of pure oil. Followed by TiO 2 nanofluid, the breakdown voltage is increased by 29.8%. Whereas for Al 2 O 3 nanofluid, it is slightly increased by 7.4%. Moreover, streamer structure, propagation length and velocity in pure oil and nanofluids were investigated using the shadowgraph technique. It is demonstrated that streamer propagations are changed in different extent with the presence of three types of nanoparticle. In Fe 3 O 4 and TiO 2 nanofluids, streamers with more branches have lower velocity than that in pure oil. Whereas in Al 2 O 3 nanofluid, streamers are similar to that in pure oil. The propagations of positive streamers in the nanofluids are notably suppressed by Fe 3 O 4 and TiO 2 textbf nanoparticles, leading to the improvements of breakdown strength. The nanoparticle effect on streamers is further confirmed by simulation.

BACKGROUND: Age-related neuromuscular changes in the hip abductor-adductor muscles lead to reduced performance, especially in the rate of force development and power production. These alterations may impair weight transfer control and lateral balance recovery through protective stepping. This study compared the effects of eight weeks of low-dose hip abductor-adductor power and strength training on the performance of isometric maximal voluntary contractions, and lateral balance recovery at different initial weight-bearing conditions in older individuals. METHODS: Eighteen healthy older adults (71.3 (0.9)yrs) underwent eight weeks of low-dose hip abductor-adductor exercise training involving either power training (n=10) or lower velocity strength training (n=8). Outcomes were assessed for hip abductor-adductor isometric maximal voluntary contractions and lateral waist-pull balance perturbations with three initial stepping limb-load conditions (50%, 65%, or 80% body mass). FINDINGS: Power training increased isometric maximal voluntary contractions abductor-adductor peak torque (14%–18%, p

This research focuses on the demonstration of the evacuation simulation as if emergency situation is occurred at Dewan Sultan Ibrahim (DSI) of Universiti Tun Hussein Onn Malaysia (UTHM) from the perspective of microscopic dynamics of crowd behaviour. The model was performed by using the DEM-based crowd behaviour simulator, namely as Crowd Behavior Simulator for Disaster Evacuation (CBS-DE) and its analysis is capable to track the trajectory and rotation of each individual. This research is based on two different cases in which the first case was using the average velocity of 1.16 m/s for both male and female and the for the second case, the velocity of 1.25 m/s was applied for male while lower velocity was applied for female which is 1.12 m/s. DSI building is considered as a well-designed building in terms of safety and convenience factors. This is due to the short time taken for the people to evacuate from the inside of the building by considering the crowds are familiar with the building as all the doors are easy to be seen.

Prospective observation of hemodynamic changes before and after the formation of atherosclerotic stenosis in the carotid artery is difficult. Thus, a vessel surface repairing method was used for retrospective hemodynamic study before and after atherosclerotic stenosis formation in carotid artery. The three-dimensional geometry of sixteen sinus atherosclerotic stenosis carotid arteries were repaired and restored as normal arteries. Computational fluid dynamics analysis was performed to estimate wall shear stress (WSS), velocity and vortex in atherosclerosis-free areas and sinus in stenosis-repaired carotid artery. The analysis was also performed in the stenotic segment and upstream and downstream of stenosis in stenotic carotid artery. Compared to the atherosclerosis-free areas in stenosis-repaired carotid artery, sinus presented significantly lower WSS (P P P P = 0.87), both upstream and downstream of stenosis demonstrated similar velocity to sinus (P = 0.76 and P = 0.36, respectively) and apparent vortex. Atherosclerosis-prone areas including normal carotid sinus and upstream and downstream of stenosis in stenotic carotid artery were subjected to lower WSS and velocity as well as apparent vortex, thereby might be associated with the formation and progress of atherosclerosis.

Conventional fiber-optic displacement interferometers operated at 1550 nm suffer from low temporal or velocity resolution for lower velocity measurements. To overcome this drawback, a fiber-optic Doppler pin system operated at 532 nm is developed, and its capability is demonstrated with low-velocity plate impact experiments. The new instrument would be an important supplemental to the existed systems.

Contextual cueing advancing the characteristics of an impending balance perturbation has been thought to induce optimized automatic postural responses. In this investigation, we aimed to disambiguate the cognitive and adaptive components of cueing a balance perturbation through the direction sequence of a series of base of support translations. We compared three experimental conditions: (a) block, with one perturbation cueing that the following one would be in the same direction; (b) serial, with one perturbation cueing that the following one would be in the opposite direction; and (c) random, representing a control uncued condition. Participants were instructed about the perturbation sequences. With this arrangement, at the cognitive level there was no directional uncertainty both in the block and serial sequences, while at the non-cognitive level only the block sequence was expected to lead to optimized responses in comparison to the random sequence. Results showed that the block sequence led to the generation of more stable automatic postural responses in comparison to the serial and random sequences, as indicated by lower amplitudes of body sway and lower velocity of center of pressure displacement. Increased balance stability in the block sequence was associated with longer delays of activation onset of leg distal muscles. Comparisons between the serial and random perturbation sequences failed to show any significant differences. These results indicate that optimized postural responses in the block sequence are due to adaptive processes underlying repetitive perturbations over trials rather than to processing of contextual cues at the cognitive level reducing uncertainty about characteristics of an impending perturbation.

An implanted disk pump for supporting blood circulation is developed and fabricated. This pump is designed for implantation to patients as a bypass for the left ventricle of the heart in order to provide temporal (up to several months) assistance for heart operation while the patient is waiting for a donor heart. The proposed pump differs from implanted pumps already available at the marker by the principle of its operation based on the phenomenon of boundary layer formation on rotating disks. The flow rates and pressure characteristics of the developed disk pump are comparable to those of other known pumps, but its rotor rotates with a lower velocity; for this reason, the probability of thrombosis is lower. The disk pump satisfies all medical and biological requirements to implanted pumps for blood circulation support.

An ultrasonic pulse velocity (UPV) test is often applied to determine the quality of concrete structures. It is well known that there are several factors which can influence the reading of ultrasonic velocity in concrete. One of the factors is the presence of steel reinforcement. Therefore, this paper is intended to evaluate the ultrasonic pulse velocity propagation either in plain or reinforced damaged concrete. A study on sound concrete is also provided as a comparison. Three mixes of concrete were provided, with 25 MPa, 35 MPa, and 45 MPa target compressive strengths. The specimens were 200x200x200 mm cube concrete specimens and 100x150x1100 mm reinforced concrete beam specimens. Each specimen was examined for velocity readings in sound and damaged concrete (25% and 50% of maximum load). In all concrete grades of both plain and reinforced concrete, the ultrasonic velocity decreases as the damage level increases. During intact conditions, the velocity of reinforced concrete is around 4.5% higher than that of plain concrete. However, damaged reinforced concrete has a lower velocity than plain damaged concrete. Furthermore, a new equation for predicting ultrasonic pulse velocity in reinforced concrete is proposed.

Les oeufs de caille proviennent de l'Unité Expérimentale de l'Inra de Tours UE PEAT The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fphys.2018.00603/full#supplementary-material; International audience; Background: Recent studies have demonstrated an effect of the gut microbiota on brain development and behavior leading to the concept of the microbiota-gut-brain axis. However, its effect on behavior in birds is unknown. The aim of the present study was to determine the effect of the absence of gut microbiota on emotional reactivity in birds by comparing germ-free (GF) quails to those colonized (COL) with gut microbiota. Material and Methods: From hatching, the quails of both groups GF (n = 36) and COL (n = 36) were reared in sterile isolators. The COL quails were colonized at day 2 by introducing a pool of droppings from conventional adult females into the drinking water and feed. The quails were weighed individually on day 2, 6, and 14. From day 8, emotional reactivity was assessed in each group in the isolators through several behavioral tests. Results: GF quails showed a considerable decrease in emotional reactivity demonstrated by spending less time in tonic immobility during the tonic immobility test (242 s ± 31 vs. 331 s ± 32, p ≤ 0.05), traveling a shorter distance (3,897 cm ± 242 vs. 4,827 cm ± 278, p ≤ 0.05) at a lower velocity (6.55 cm/s ± 0.4 vs. 8.1 cm/s ± 0.5, p ≤ 0.05) during the social separation test and spending more time near an object at the beginning of the novel object test (33.7 s ± 6.4 vs. 18.5 s ± 4.1, p ≤ 0.05). No difference in growth was found between the 2 groups. Conclusion: For the first time, this study demonstrates that the absence of gut microbiota reduces emotional reactivity in Japanese quails in situations of fear and social perturbation without influence on growth.

Nearly all manufactured products in the metal industry involve welding. The detection and correction of defects during welding improve the product reliability and quality, and prevent unexpected failures. Nonintrusive process control is critical for avoiding these defects. This paper investigates the detection of burn-through damage using noncontact, air-coupled ultrasonics, which can be adapted to the immediate and in-situ inspection of welded samples. The burn-through leads to a larger volume of degraded weld zone, providing a resistance path for the wave to travel which results in lower velocity, energy ratio, and amplitude. Wave energy dispersion occurs due to the increase of weld burn-through resulting in higher wave attenuation. Weld sample micrographs are used to validate the ultrasonic results.