Length Of Stretch Research Articles

Study on the Applicability of Elastic Recovery (Resilience) Experiment for Asphalt-Rubber

In this paper, the applicability of the elastic recovery (resilience) experiment for asphalt-rubber (AR) binders has been quantitatively assessed. The mechanical model, based on the viscoelastic constitutive relation and particle inclusion theory, was developed. The interfacial detachment between crumb rubber (CR) particles and asphalt caused by stress concentration was analyzed with Weibull statistical equations. Based on the road roughness excitation, the vehicle-road coupling vibration model was established to analyze the impact of vehicle loading on road surface deformation. AR binders with different CR particle sizes were assessed using scanning electron microscope (SEM) imaging and prepared for testing the elastic recovery (resilience). The results showed that the greater internal stress caused by the longer stretch length of AR binders in the elastic recovery experiment was ten times higher than that obtained from the resilience experiment, leading to the interfacial detachment between asphalt and the CR particles. Hence, the elastic property of some of the CR particles with high modulus was not reflected, resulting in the test values being lower than actual values. With the reduction of CR particle size, the interfacial detachment was improved in the elastic recovery experiment due to intense material interchange and the enhancement of interfacial bond strength. The millimeter-scale compression deformation of the AR binder in the resilience experiment was closer to the actual deformation of the road surface. The experimental time of resilience (120 min) has been reported less than that for elastic recovery (200 min–230 min). This study shows that the resilience experiment has a significant advantage in assessing the elastic property of the AR binder.

Free Electrons Compton Scattering Can Produce an Illusion of Expanding Universe

The high-precision measurements of the Hubble parameter make the theory of cosmic expansion more and more confusing, which bolsters the idea that new physics may be needed to explain the mismatch. Astronomical observations show that the Universe is expanding exponentially. Free electron Compton scattering (FEC) can produce the illusion of exponentially expanding Universe: FEC causes photons to redshift exponentially, and the photon beam exponentially expands along the propagation direction. Is this a coincidence? The redshift factor of the FEC is z = (1+z); the beam length stretch factor (time dilation of the supernova curve) of the FEC is z = (1+z); the expansion factor of the beam volume of the FEC is z = (1+z)3, and the FEC effect does not blur the image of distant galaxies. The reason for rejecting the “tired light” does not hold in FEC.

Identifikasi Bidang Gelincir Tanah Longsor Menggunakan Metode Geolistrik Konfigurasi Schlumberger di Perumahan Ayudia Semarang

This study aims to identify the potential for landslides in the Ayudia housing location, Semarang. The data obtained in this study were apparent resistivity data using the geoelectric resistivity method of the Schlumberger configuration. Measurements were carried out on two tracks, namely the first track with a stretch length of 150 m and electrode spacing of 10 m and the second track with a stretch length of 75 m and electrode spacing of 5 m. Res2dinv software was used to display the resistivity value on each track so that a color image is seen that describes the change in resistivity in each rock layer. The results of the study indicated the identification of the location of the slip plane on the first track with a layer that is suspected to be the slip plane, namely limestone with resistivity values (307-939) Ωm and is at a depth of (19,9-26.9) m. This layer had a higher resistivity contrast than the top layer of the slip plane in the form of sandstone which can store water content. Thus, it could be concluded that the first track identified the potential for landslides to occur.

Reference Range of Penile Dimensions of the Adult Male and Correlation with Somatometric Parameter in a Tertiary Care Hospital of Bangladesh: A Prospective Study

Background: The penile size has always been a symbol of manliness and pride. Many adult think that there penile length are not adequate and goes to different medical disciplines. There is no study in Bangladesh regarding penile size and somatometric parameter. The results will help in counseling patients afraid of their penile size , also in clinical and research purpose. Objective: To assess the penile size in different dimensions such as flaccid, stretch, and girth (circumferential) penile length and its relationship with age, height, weight, and BMI. Materials and Methods: The study was conducted on 300 adult males with no penile abnormalities. Length of penises in flaccid, stretch, and circumference were measured. Age ,height, weight were measured and BMI (body mass index) was calculated. Correlation of penile dimensions with somatometric parameters were analyzed. Results: The average flaccid penile length(FPL) was 7.81 cm, the mean stretch length(SPL) was 11.21 cm, and the mean circumferential length(CPL) was 8.65 cm. The penile length in the three dimensions was significantly different from each other (p<0.05). A significant correlation was found among the three penile dimensions (p<0.05). Conclusion: The penile size in different dimensions can be varied with age,height,weight and BMI. KYAMC Journal. 2021;12(3): 122-126

Self-Centering Bridge Bent with Stretch Length Anchors as a Tension-Only Hysteretic Hybrid System

AbstractAccelerated bridge construction (ABC) incorporates innovative techniques to reduce construction time and traffic disruption. The objective of the research was to design, build, and test a s...

Geodesic stretch, pressure metric and marked length spectrum rigidity

AbstractWe refine the recent local rigidity result for the marked length spectrum obtained by the first and third author in [GL19] and give an alternative proof using the geodesic stretch between two Anosov flows and some uniform estimate on the variance appearing in the central limit theorem for Anosov geodesic flows. In turn, we also introduce a new pressure metric on the space of isometry classes, which reduces to the Weil–Petersson metric in the case of Teichmüller space and is related to the works [BCLS15, MM08].

Mixing driven by transient buoyancy flows.II. Flow dynamics

The chaotic advection of the interface between two miscible liquids inside a closed cavity, generated by a damped oscillatory buoyancy-driven (BD) regular flow field, is investigated experimentally for BD mixing. The Lagrangian history of interface motion, determined using the planar laser-induced fluorescence and the photographic full-field view method, is contrasted against the Eulerian flow field measured from particle image velocimetry. Chaotic advection stretches and folds the interface at an early stage to produce an asymmetric pairwise Rayleigh–Taylor (RT) morphology (RTM) structure from long wavelength RT instability and short-time Richtmyer–Meshkov instability and its fractal interface structure at a high impulsive-Reynolds number. The mechanism of folding, from global bifurcation of the flow field, caused by a hyperbolic point, served as an organizing center for multiple vortex interactions. The intermediate-stage kinematics of the RTM structure exhibits RT mixing and shows unfolding of the lamellar structure from the net effect of stretching, folding, and molecular diffusion prior to its breakdown; and it has a probabilistic outcome of exhibiting topological transitions through a breakup of the RTM structure in phase space from necking singularity and pinch-off, indicating sensitivity to the initial conditions. The effectiveness of mixing determined from mixing efficiency is contrasted against mechanical and lamellar models of mixing. The determination of topological entropy, from an approximate Gaussian distribution of the interface length stretch, yields time scale for information decay comparable to time scale for which a low-order horseshoe map emerges from flow, indicating local chaos of the interface. The late-stage breakdown of the RTM structure from internal and wall collision drives the interaction between advection and diffusion, which indicates that critical mixing time scales as the logarithmic of Peclet number, comparable to time-periodic sine flow and blinking vortex flow chaotic mapping models.

WDR47 protects neuronal microtubule minus ends from katanin-mediated severing.

Axons and dendrites are long extensions of neurons that contain arrays of noncentrosomal microtubules. Calmodulin-regulated spectrin-associated proteins (CAMSAPs) bind to and stabilize free microtubule minus ends and are critical for proper neuronal development and function. Previous studies have shown that the microtubule-severing ATPase katanin interacts with CAMSAPs and limits the length of CAMSAP-decorated microtubule stretches. However, how CAMSAP and microtubule minus end dynamics are regulated in neurons is poorly understood. Here, we show that the neuron-enriched protein WDR47 interacts with CAMSAPs and is critical for axon and dendrite development. We find that WDR47 accumulates at CAMSAP2-decorated microtubules, is essential for maintaining CAMSAP2 stretches, and protects minus ends from katanin-mediated severing. We propose a model where WDR47 protects CAMSAP2 at microtubule minus ends from katanin activity to ensure proper stabilization of the neuronal microtubule network.

Hydrodynamics and mixing process in a horizontal self-cleaning opposite-rotating twin-shaft kneader

The finite element method (FEM) simulation was adopted to investigate the hydrodynamics in an opposite-rotating horizontal self-cleaning twin-shaft kneader with a highly viscous Newtonian fluid. The complicated motion of impellers was simulated by using the mesh superposition technique (MST). The particle tracking technique was used to evaluate the mixing process. The stretching rate from the trajectories of particles was quantitatively characterized to calculate the mixing efficiency. A small visual experimental apparatus was also designed to study the mixing process. The mixing processes by visual experiment show good agreement with the FEM simulation data. The velocity and shear rate are larger in the faster rotation speed side since the rotation speeds of these two shafts differs. The kneading bars on the left and right shaft only intermesh in the center of the overlapping zone. There exists the material exchange between the left and right chamber due to periodical intermeshing interaction. The intermeshing kneading bars split the center-initial cluster into two parts and push them into the left and right region of the lower part of the kneader, respectively. The mean length of stretch increases exponentially with time. The mean value of the mixing efficiency remains positive at all times.

984 Novel measures of cervical deformation properties on transvaginal ultrasound and prediction of time to delivery

To examine deformation characteristics of the cervix during transvaginal ultrasound (TVUS), as a surrogate for cervical softening, in relation to time to delivery. Prospective cohort study of patients undergoing longitudinal cervical imaging. We assessed TVUS exams from 20 weeks to within 1 week of delivery. B-mode video captured standard cervical length (CL) views including the cervical canal, and internal and external os under pressure and release cycles. Cervical deformation characteristics were: CL length stretch ratio defined as CL at the highest pressure divided by CL at the lowest pressure (as the cervix becomes softer it elongates more with pressure), and Anterior-posterior cervical thickness ratio defined as thickness of the anterior layer of cervix divided by thickness of the posterior layer (as the cervix softens, pressure on anterior layer is not transmitted effectively to the posterior layer and it is less compressed) (Fig. 1). These measures were compared between time windows to assess progression of cervical softness as pregnancy progressed in term(T) and spontaneous preterm (PT) births. 160 patients were included; 114 T and 46 PT births. In both T and PT births, the CL stretch ratio significantly increased 1-2 weeks before delivery compared to 3-4 weeks. The anterior-posterior thickness ratio also significantly decreased 1-2 weeks before delivery in T birth. Measures at all time points from 3 to 20 weeks before delivery did not significantly differ, suggesting that cervical softening occurs proximal to delivery in both T and PT births (Fig 2). Measures in T and PT births were similar distant from delivery (3-20 weeks) and proximal to delivery (within 2 weeks), suggesting that cervical ripening patterns are similar, but occur earlier in PT births. We report novel measures of cervical deformation properties easily obtained by TVUS that change 1-2 weeks before delivery. These measures warrant further investigation for clinical application to detect timing of both T and PT deliveries.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Controllable curl-correction of 3D frame fields

Hexahedral meshes represent an attractive discretization strategy in finite element analyses owing to their good numerical performance. Frame field-based remeshing is an important technique for controllable hexahedral meshing. Existing frame-field generation methods cannot be directly used for purely hexahedral meshing due to possible topological conflicts. These problems are less severe in the case of hexahedral-dominant meshing. However, the quality of these hexahedral-dominant meshes is largely affected by the curl of the input frame fields. With the aim of overcoming this issue, we propose a direction-preserving and length-controllable curl-correction method of 3D frame fields. We analyze and construct the discretized curl energy of the 3D vector field on tetrahedral meshes and extend it to frame fields, i.e., the composition of three vector fields. In order to preserve the input directions as much as possible, three scalar fields were introduced to denote the stretch length of the three vectors of the frame fields and represent the new fields as a combination of the original frame fields and scalar fields. Through global-optimization of the curl energy combined with a smooth term, the final curl-corrected frame fields are obtained, which are further used for hexahedral-dominant remeshing. The results indicate that the proposed method can reduce the curl of the frame fields efficiently while keeping their directions as well as controlling the extent of their length. By applying such frame fields to existing hexahedral-dominant remeshing methods, direction- and size-controllable hexahedral-dominant meshes can be obtained. Besides, the proposed method deduces to a convex quadratic programming problem with simple box constraints, which is easy-to-solve.

Deformation and vibration analysis of compressor rotor blades based on fluid-structure coupling

Under the influence of aerodynamic and rotational load, deformation and vibration could occur to rotor blades of axial compressor, which may cause fatigue fracture, and threaten the exist of tip clearance because it is the assurance of operation safety by separating the rotor from the case. The overall performance will be deteriorated by the change of blade shape due to the deformation and vibration. Three different materials, titanium alloy, aluminum alloy and stainless steel are compared quantitatively under various operating conditions by fluid-structure coupling method. First the CFD method is validated by experimental data, the obtained pressure distribution on blade surface is exerted to the structure as boundary condition, then deformation characteristic and the corresponding maximum equivalent stresses are analyzed, at last vibration modal is analyzed and resonance points, the main reason for the vibration-induced failure, are predicted by Campbell diagrams. The results show that deformation increases with rotation speed and outlet pressure; the aluminum alloy has the largest deformation of the three materials. The equivalent stress of the blade is mainly caused by rotation, large stress regions are often near the blade root. The tip clearance of rotor blades can be reduced by deformation in the radial direction, for titanium and aluminum alloy blade, the maximum stretched length of blade at 100% rotation can account for 30% of the designed tip clearance. Centrifugal loading is the main reason for the increase of natural frequency while the increased amplitude with rotation speed is extremely small compared to the first order natural frequency.

Modeling the minus two base pair stutter ratio of the D1S1656 locus: A sequence-based mixture distribution model

In this study, we propose a stutter ratio for a minus two base pair stutter (-2bpSR) model of the D1S1656 locus in capillary electrophoresis (CE)-based short tandem repeat (STR) typing. DNA from a total of 108 Japanese individuals was analyzed via massively parallel sequencing to investigate the length of the longest uninterrupted stretch of two base repeat motif (2bpLUS value) within repetitive structures involving the flanking region. Additionally, -2bpSR data was collected using the GlobalFiler Kit on a 3500xL Genetic Analyzer. As a result of sequencing analysis, all alleles were classified into two types by their 2bpLUS values. The -2bpSR differed significantly between the types. Then, we modeled the -2bpSR with a mixture log-normal distribution using the classification of alleles based on the 2bpLUS values. Furthermore, probabilities of the sequence type within each repeat number in the mixture log-normal distribution model were estimated using logistic regression for each of the five major detected populations. This study is expected to enable interpretation of STR typing while considering minus two base pair stutter at the D1S1656 locus.

Axial formation and cross-section distortion control for stretch bending based on batch simulations

Stretch bending is a widely used to form long parts with a definite cross-section shape. The forming path is an effective way to eliminate the defects such as springback, distortion when the material and the die shape are determined. In this study, the stretch bending path is represented by a curve function of bending angle and stretch length. To simplify the path optimization problem, the path is represented by 4 parameters, including a newly introduced parameter of total stretch. Based on the batch simulation results, it is found that the axial springback and cross section distortion are primarily controlled by total stretch, bending angle and pre-stretch proportion. When the total stretch is determined, the different distribution schemes for pre-stretch, bending stretch and post-stretch in total stretch have a similar effect on forming quality except the schemes with extremely large proportions of pre-stretch. In most cases, with the total stretch length in growth, the axial springback decreases dramatically at first and then stays constant while the section distortion continues to rise, indicating that the optimal forming path is around the elbow point in the relationship curve of total stretch and springback angle. The optimal path is verified by experiments. It is shown that for a workpiece with determined material and die shape, the optimal path to minimize axial rebound and section distortion simultaneously does exit and the study provide an effective way to obtain it.

Cyclic Tests and Modeling of Stretch Length Anchor Bolt Assemblies for Dry Storage Casks

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Traumatic index extensor tendon attenuation mimicking closed tendon rupture: two case reports

BackgroundWhile some traumatic closed index extensor tendon ruptures at the musclotendinous junction have been previously reported, closed index extensor tendon pseudorupture due to intertendinous attenuation is exceedingly rare with only one case report of a gymnastics-related sports injury in the English literature. Herein, we report two non-sports injury related cases of traumatic index extensor tendon attenuation mimicking closed tendon rupture, including the pathological findings and intraoperative video of the attenuated extensor indicis proprius tendon.Case presentationA 28-year-old man and a 30-year-old man caught their hands in a high-speed drill and lathe, respectively, which caused a sudden forced flexion of their wrists. They could not actively extend the metacarpophalangeal joints of their index fingers. Intraoperatively, although the extensor indicis proprius and index extensor digitorum communes tendons were in continuity without ruptures, both tendons were attenuated and stretched. The attenuated index extensor tendons were reconstructed either with shortening by plication or step-cut when the tendon damage was less severe or, in severely attenuated tendons, with tendon grafting (ipsilateral palmaris longus) or tendon transfer. Six months after the operation, the active extension of the index metacarpophalangeal joints had recovered well.ConclusionsTwo cases of traumatic index extensor tendon attenuation were treated successfully by shortening the attenuated tendon in combination with tendon graft or transfer. We recommend WALANT (wide-awake local anesthesia and no tourniquet) in the reconstruction surgery of index extensor tendon attenuation to determine the appropriate amount of tendon shortening or optimal tension for tendon grafting or transfer. Intraoperative voluntary finger movement is essential, as it is otherwise difficult to judge the stretch length of intratendinous elongation and extent of traumatic intramuscular damage affecting tendon excursion.

Recruitment dynamics of a migratory fish in a semiarid river system

ABSTRACT Recruitment dynamics of Neotropical migratory fishes are widely studied in river–floodplain systems, where the flood pulse and wetlands play a central role. In semiarid systems, where the flow regime is less predictable and waterbodies are intermittent, migratory fishes may employ different recruitment strategies. We investigated factors affecting the recruitment dynamics of a migratory fish (Prochilodus hartii) in a semiarid river basin (Jequitinhonha River, Brazil) subjected to river regulation. We sampled eggs, larvae, young-of-the-year (YOY), and subadults over multiple years and at several sites distributed along 300 km of the Jequitinhonha River. Biotic variables were investigated against 13 predictors through different modeling approaches to examine (1) spawning dynamics and its relationship to the flow regime, (2) habitat features related to the presence of YOY, and (3) the relationship between recruitment and floods. Higher densities of eggs and larvae occurred at sites with no influence of river regulation, affected mainly by weekly and daily variations in water level. YOY detection increased by 40% when a lateral stream was present, and occupancy was affected by the length of the lotic stretch. Subadult abundance was not correlated with any predictor related to the flooding regime. Our results show that spawning took place at multiple sites, affected mainly by flow variations, while development and recruitment occurred mostly within river channels and in the confluence of small intermittent tributaries, with little dependence on floods. Therefore, fish recruitment in this semiarid system showed different relationships with floods when compared with river–floodplain systems, highlighting the singularity of drylands.

An Innovative Strategy for Non-Grafting Penile Enlargement: A Novel Paradigm for Tunica Expansion Procedures

BackgroundPeyronie’s disease, diabetes, trauma, pelvic surgeries, and aging are conditions that promote penile fibrosis and trigger erectile dysfunction associated with penile reduction. These pathologies require an objective preoperative diagnosis and intraoperative management of penile shrinkage. AimThe goal is to develop a non-grafting procedure to promote lengthening using geometric patterns of multiple staggered small cuts on the tunica albuginea with an optimal ratio between tissue expansion and resistance to confine the cylinders inside the corpora cavernosa. MethodsBetween February 2016 and February 2019, 416 patients suffering penile shortening with or without Peyronie’s disease received implants using the tunica expansion procedures (TEP). Incisions were distributed in respective areas of the tunica to allow maximum expansion while maintaining strength to confine prosthetic cylinders within the corpora cavernosa to prevent bulges and denting. OutcomesIn accordance with these principles, surgical objectives and patient satisfaction were achieved in length and girth restoration regardless of the type of implant used to obtain adequate axial rigidity. ResultsThe sample of 416 patients included 287 cases of Peyronie’s disease having a mean axial deviation of 51° (0–90°) whose curvature was corrected in surgery, with pressure from the cylinders maintaining straightness for malleable and inflatable devices. Tunica constriction in 40.86% of cases was corrected with vertical relaxing incisions. Ventral glanspexy was performed intraoperatively in 92.8% of patients to prevent hypermobility. A penile gain of 3.3 cm (2–6) was measured intraoperatively. Clinical ImplicationsDiagnosis of penile shortening was performed by a stretch length test and pharmacologically induced erection together with the patient’s subjective opinion of penile loss. Lengthening procedure depends on the limit of the dissected neurovascular bundle. The patient and surgeon select the type of implant in accordance with his individual anatomic characteristics. Strengths and LimitationsThe TEP strategy is a non-grafting procedure based on tissue restitution by expansion instead of substitution, which provides surgeons a solution for penile enlargement to the limit of the dissected neurovascular bundle. ConclusionsThe TEP strategy has been demonstrated to be safe and effective to resolve problems of penile size reduction independently of penile curvature. It eliminates grafting and improves penile lengthening techniques using small, staggered cuts on the tunica albuginea, while maintaining tunica structural resistance to contain cylinders inside the corpora, preventing bulges and denting, facilitating tissue regeneration, and improving axial rigidity.Paulo H. Egydio, An Innovative Strategy for Non-Grafting Penile Enlargement: A Novel Paradigm for Tunica Expansion Procedures. J Sex Med 2020;17:2093–2103.

Using a Digital Microfluidic System to Evaluate the Stretch Length of a Droplet with a L-DEP and Varied Parameters

Digital microfluidics has become intensively explored as an effective method for liquid handling in lab-on-a-chip (LOC) systems. Liquid dielectrophoresis (L-DEP) has many advantages and exciting prospects in driving droplets. To fully realize the potential benefits of this technique, one must know the droplet volume accurately for its distribution and manipulation. Here we present an investigation of the tensile length of a droplet subjected to a L-DEP force with varied parameters to achieve precise control of the volume of a droplet. Liquid propylene carbonate served as a driving liquid in the L-DEP experiment. The chip was divided into two parts: an electrode of width fixed at 0.1 mm and a total width fixed at 1 mm. Each had a variation of six electrode spacings. The experimental results showed that the stretching length decreased with decreasing electrode width, but the stretching length did not vary with an increased spacing of the electrode. When the two electrodes were activated, the length decreased because of an increase in electrode spacing. The theory was based on the force balance on a droplet that involved the force generated by the electric field, friction force, and capillary force. The theory was improved according to the experimental results. To verify the theoretical improvement through the results, we designed a three-electrode chip for experiments. The results proved that the theory is consistent with the results of the experiments, so that the length of a droplet stretched with L-DEP and its volume can be calculated.

Prediction Model of Build Rate of Push-the-Bit Rotary Steerable System

The accurate prediction of build rate of rotary steerable system (RSS) is the prerequisite for the precise control of wellbore trajectory and optimal design of the steerable tool. Push-the-bit RSS refers to a steerable drilling system that controls well trajectory through adjustment of stretch length of pushing block. Based on this feature, a three-dimensional mechanical model of push-the-bit RSS is established on the basis of the conventional steerable tool mechanical model while considering pushing force. Meanwhile, the effects of bit cutting performance and formation anisotropy are considered. Next, the lateral force method, inclination trend angle method, and ultimate build rate method based on zero lateral force are analyzed and a new ultimate build rate method based on zero lateral drilling penetration is built. A conversion coefficient is introduced to reflect the ratio of actual build rate to theoretical build rate. At last, the new model is applied to a case study. The new method is superior to other previous methods, because the effects of bit-rock interaction and actual drilling process are sufficiently considered. The influence mechanism of build rate includes “leverage effect,” “pendulum effect,” and “pushing effect.” The build rate of steerable tool is a comprehensive outcome of various effects, of which the “pushing effect” plays a dominant role. With the increase of weight on bit (WOB), the proportion of “leverage effect” increases, while the proportion of “pushing effect” decreases, and therefore the build rate decreases.