Stiffness

When an asphalt binder is modified through a wet process, high temperatures and long mixing times are used. In most research carried out on this subject, it has been concluded that, when modifying asphalts through a wet process, the base asphalt's stiffness increases. However, the contribution the used modifier makes to this mechanical parameter is unclear, as well as what is the effect of elevated mix temperatures (T) and times (t). In order to evaluate the influence of T and t, this study designed an experimental phase that attempts to simulate within a laboratory, the wet modification process of an AC 60-70 asphalt binder. AC 60-70 was exposed to similar T and t to those found in several asphalt modification studies, in order to then manufacture with said asphalts, Hot Mix Asphalts (HMA). HMAs were subjected to Marshall Tests, Indirect Tensile Strength Tests (ITS), Cantabro Test, Resilient Modulus and Permanent Deformation Tests. Each of the test results were subjected to an Analysis of Variance (ANOVA) tests. As a general conclusion, we obtained that T and t have a significant influence in the asphalt binder response as well as in the response of HMAs, mainly in terms of stiffness and adherence.

Two trial piles were installed at the berm section of an embankment in the later stage of its construction and one of them was fitted with an oversized casing to isolate its top 3. m from the action of surrounding soil. Lateral bending behaviour these two piles subjected to passive sub soil movements were very different from each other because of the casing and is modelled in this paper using a three dimensional analysis. The effect of relative stiffness of the piles on their lateral bending behaviour is investigated. The effect of interface joint slip on the pile's behaviour is also investigated in a later section of this paper. © 2013 Elsevier Ltd.

http://www.sciencedirect.com/science/article/pii/S0266352X13000591

Mechanical properties were evaluated for pulp delignified by four deep eutectic solvents (DES). The DES systems were based on choline chloride and lactic acid (1:9), oxalic acid:dihydrate (1:1), malic acid (1:1), and the system alanine:lactic acid (1:9). The results indicated that the type of DES system used influenced the delignified pulp's mechanical properties including tensile, burst and tear indexes, tensile length, and stiffness. The most suitable DES systems were choline chloride:malic acid (1:1) and alanine:lactic acid (1:9), which achieved the best aforementioned mechanical properties compared to the other DES systems. The weakest performance in the process of pulp delignification was the system with choline chloride and oxalic acid dihydrate (1:1).

roduction
Trigger finger is a common condition with a reported prevalence
of 2% to 20% [1,2]. Generally, trigger finger affects women more
than men and the age distribution is bimodal with one group below
six years of age and the other in their fifth and sixth decade of lif.
It is a disorder which is associated with entrapment of the flexor
digitorum superficialis or flexor digitorum profundus tendon
along its course through fibro-osseous tunnels of the wrist, palm
and digits of the hand [1]. Onset is usually gradual, associated
with repetitive tasks, unaccustomed activity or compression of the
pulley against hard objects. Snapping, clicking, locking, stiffness,
and difficulty extending a flexed digit, often with discomfort or pain,
are the most prominent symptoms [3,4]. Several studies suggest
that individuals with type 1 diabetes, rheumatoid arthritis, carpal
tunnel syndrome, arthritic changes in the wrist, hypothyroidism,
mucopolysaccharidoses, amyloidosis, and congestive heart failure
may be predisposed to flexor tendon entrapment [1].

This paper proposes a 4WAS (4 Wheel Active Steer) system assists drivers by automatically controlling the steering angle of a vehicle's four wheels according to speed. By controlling the steering angle of all four wheels, this active steering system helps improve stability and response at high speed and helps reduce driver's steering workload at low speed. The study compared the operation of the system with and without PID controller. Computer simulations demonstrate good maneuverability of the proposed system.

— The natural frequency of 1-degree spring mass system can be calculated by using three well-known analytical methods (viz. Equilibrium method, Maximum energy method, and Rayleigh's method). The Equilibrium method is based the Newton's second law of motion and the D'Alembert's principle. The Maximum energy method and Rayleigh's method are based on the kinetic energy and potential energy of system. In this paper, the natural frequency of an un-damped spring mass system is calculated experimentally and compared it with that of the analytical value. The effect of mass and stiffness of system on the natural frequency is also discussed. The effect of experimental and exact (theoretical) natural frequencies is explained in detail.

Shear wall is one of the most commonly used lateral load resisting in high rise building. Shear wall has high in plane stiffness and strength which can be used to simultaneously resist large horizontal load and support gravity load. The objective of the present study is to study the behavior of building frame in the lateral load analysis of shear wall-frame structures; a fundamental goal is to model the shear wall assemblies using a realistic and feasible method.

The crank arm is the component of the bicycle that transfers the force exerted on the pedals to the crank set. Crank arms can crack in a number of places. Sometimes a crack will develop between the pedal mounting hole and the end of the arm. This research is basically deal with to analyse the structural analysis of crank arm by using the three different materials.The problem to be dealt for this work is to design and simulate using SolidWorks software for the optimization of the crank arm with constraints of stiffness and strength is considered for design safety.The crank is analyzed in static condition. Distribution of different stress components and the maximum von Misesstress have been ascertained. The maximum von-Mises stress 106.6MPa and maximum deflection is 0.282mm found that on the alloy steel material. So alloy steel is the suitable material of the crank arm for Quadracycle.It has been found that the maximum von Mises stress in the crank is 106.6 MPa which is below the yield strength of the crank material (620.42 MPa).

Using fiber reinforced polymer (FRP) bars as an alternative to traditional steel
reinforcement solves durability problems in reinforced concrete structures. This study
investigated the effects of bar slippage on the pre- and post-heating flexural response
of concrete beams reinforced with different FRP and conventional steel bars. A total
of twenty-four control and heat-damaged concrete beams with different FRP/steel
bars were loaded (in triplicates) under a four-point loading configuration to evaluate
their mechanical performance and failure modes while acquiring strains in tension
steel and compression concrete. A new theoretical method was proposed to predict
the load capacities of the beams with consideration of slippage between the FRP bars
and surrounding concrete. The results were then compared with the load capacities
computed using the ACI code that assumes a prefect bond between FRP bars and
concrete. The post-heated concrete beams failed at a relatively low load capacity.
They also presented an increase in deflection and ductility and a decrease in stiffness
and total absorbed energy. The theoretical ultimate load of the FRP-RC beams,
computed on the basis of the ACI code, was overestimated relative to the
corresponding measured values. By contrast, the computations based on the actual

Internal combustion engines are the precursor of modern automobile technology, therefore it is of high importance to make exhaust analysis upon its operation. A very important part of an internal combustion engine is the piston, a moving part that consists in a connecting rod and other parts. The scope of this report is to analyze the forces that the AK EVO 150CC R3 piston connecting rod is subjected to and its common motion.

Today, virgin polymer modified asphalt mixes are comparatively more expensive for road pavement. One way to reduce the expense of such construction and to make it more convenient is the application of inexpensive polymer, such as waste polymer. The primary aim of this study was to investigate the effect of adding waste tyre rubber (crumb rubber modifier (CRM)) on the stiffness and fatigue properties of stone mastic asphalt (SMA) mixtures. Various percentages of waste CRM with size of 0.60 mm were added to SMA mixtures. Indirect tensile stiffness modulus test was conducted at temperatures of 5, 25, and 40°C. Indirect tensile fatigue test was conducted at three different stress levels (2000, 2500, and 3000 N). The results show that the stiffness modulus of reinforced SMA samples containing various contents of CRM is significantly high in comparison with that of nonreinforced samples, and the stiffness modulus of reinforced samples is in fact less severely affected by the increased temperature compared to the nonreinforced samples. Further, the results show that CRM reinforced SMA mixtures exhibit significantly higher fatigue lives compared to the nonreinforced mixtures help in and promotion of sustainable technology by recycling of waste materials in much economical and environmental-friendly manner. © 2013 Nuha Salim Mashaan et al.

http://www.hindawi.com/journals/amse/2013/319259/abs/

Long bones are composite materials possessing nonhomogeneous and anisotropic properties. They repair themselves (self-repairing) and adapt to changing mechanical demands by altering their shape and mechanical properties (self-adapting). Such exceptional features make long bones intriguing materials to comprehend properly. This also expands our knowledge of engineering materials and motivates researchers to employ novel techniques where conventional approaches may present limitations. This paper delves into the use of artificial neural network (ANN) expert systems to predict load-displacement curves of a long bone. Thirteen hydrated third metacarpal (MC3) bones from thoroughbred horses aged from twelve hours to three years were loaded in compression in an MTS machine. Strain readings from one three-gauge rosette and three distinct single-element gauges at different locations on the MC3 midshaft, displacement, load, load exposure time, horse age and bone side (left or right limb) were recorded for each bone. This information shaped ANNs input variables. Two in-series feedforward back-propagation ANNs were employed where the experimental recordings except for load were fed into the first ANN to predict load. Then, the predicted load along with the rest of experimental recordings were fed into the second ANN to predict displacement. Cyclic load-displacement and stiffness predicted by ANNs were plotted versus experimental counterparts. ANNs regression analyses showed R > 0.95 for training and testing datasets. To confirm their accuracy, ANNs were used to predict responses of specific bone samples that were not used in ANNs training. The ANNs trained using 17,718 experimental data points from twelve bones predicted the load (R = 0.997, RMSE = 2.44 kN), displacement (R = 0.948, RMSE = 0.321 mm), and stiffness (R = 0.982, RMSE = 1.197 kN/mm) of the thirteenth bone. The encouraging outcomes exhibit the exceptional ability of artificial neural networks in capturing the mechanical characteristics of complex structures.

As haptics becomes an integral component of scientific data visualization systems, there is a growing need to study "haptic glyphs" (building blocks for displaying information through the sense of touch) and quantify their information transmission capability. The present study investigated the channel capacity for transmitting information through stiffness or force magnitude. Specifically, we measured the number of stiffness or force- magnitude levels that can be reliably identified in an absolute identification paradigm. The range of stiffness and force magnitude used in the present study, 0.2-3.0 N/mm and 0.1-5.0 N, respectively, was typical of the parameter values encountered in most virtual reality or data visualization applications. Ten individuals participated in a stiffness identification experiment, each completing 250 trials. Subsequently, four of these individuals and six additional participants completed 250 trials in a force-magnitude identification experiment. A custom-designed 3 degrees-of-freedom force-feedback device, the ministick, was used for stimulus delivery. The results showed an average information transfer of 1.46 bits for stiffness identification, or equivalently, 2.8 correctly-identifiable stiffness levels. The average information transfer for force magnitude was 1.54 bits, or equivalently, 2.9 correctly-identifiable force magnitudes. Therefore, on average, the participants could only reliably identify 2-3 stiffness levels in the range of 0.2-3.0 N/mm, and 2-3 force- magnitude levels in the range of 0.1-5.0 N. Individual performance varied from 1 to 4 correctly-identifiable stiffness levels and 2 to 4 correctly-identifiable force-magnitude levels. Our results are consistent with reported information transfers for haptic stimuli. Based on the present study, it is recommended that 2 stiffness or force-magnitude levels (i.e., high and low) be used with haptic glyphs in a data visualization system, with an additional third level (medium) for more experienced users.

Seismic protection of structures is a need-based concept aimed to improve the performance of a structure subjected to earthquakes. Earthquakes of varying magnitude have occurred not only in India but also all over the world, causing extensive damage to life and property. It is well known that by designing a ductile structure and letting it yield under strong earthquakes, the forces acting on the structure can be reduced. However, when the structure yields it undergoes permanent displacement and weakens. There are many such devices developed in Structural Engineering which serves the purpose of Structural Safety such devices are dampers, base isolaters, bracings, springs etc. Another such device recently developed is NSD (Negative Stiffness Device). The NSD is a device that produces a force which is in the same direction as the imposed displacement thus the name "negative stiffness." This paper studies the concept of NSD to enhance the performance of the structure for its safety under earthquake. The study will focus to study and find the different parameters which will act as a measure of seismic performance of RCC Moment Resisting Framed Structure using Negative Stiffness Device. The study will focus on finding out the parameters like Base Shear, Base Acceleration, Top Acceleration, Top Displacement and Time Period of the G+10 multi-storey RCC building.

A control reinforced beam and four reinforced concrete beams with various extent of defects in the form of voids and load-induced cracking were analyzed. Local flexural stiffness at each coordinate point was derived by substituting the regressed data at that point and using the centered-finite-divided-difference formula. The results of the first derivative of the local flexular stiffness for the reinforced concrete beams with voids were compared with those obtained from a similar beam with cracks in the middle. The results were also compared with a similar beam with cracks on the right side of the beam.

sem-proceedings.com/19i/sem.org-IMAC-XIX-193603-Detection-Defects-Reinforced-Concrete-Beams-Using-Modal-Data.pdf

Tilting pad thrust bearings are designed to transfer high axial loads from rotating shafts with minimum power loss. In the present paper, formulation of Reynolds' equation for the bearing is done in two dimensions (planar). A finite difference method is used to convert the terms of the Reynolds' equation in to a set of simultaneous linear algebraic equations. A solution procedure for finding value of the pressure in the oil film is described. Numerical integration of the pressure values gives the load distribution. Subsequently, the study of dynamic stiffness and damping characteristics of the bearing is done by varying the value of the oil film thickness and introducing vertical velocity in the runner. Large thrust bearing behavior in a realistic configuration allowing sufficient parameter variation to check the fidelity of this analytical model is to be developed. This data is useful as an input for rotor dynamics studies of the vertical rotors. The agreement supports the fidelity and accuracy of the software package and its continued use in analysis and design.

Earthquakes are the most challenging forces that affect the buildings and other structures. The behaviour of a building during an earthquake depends on various factors such as shape, size and geometry of the building. The growth of population and the scarcity in the availability of land has constrained the architects and engineers to provide areas of parking inside the building leading to the formation of a weak/soft storey inside the building. Also the desire to build aesthetically appealing structures has inspired the engineers to build structures different from the conventional ones. The engineers are nowadays building structures different in plan and configuration. Due to recent demand of building structures aesthetically different, the plan, configuration and other geometrical features such as shape and orientation of the columns are changed. These geometrical features such as shape of columns and their orientation influences the lateral stiffness of the building .The inclusion of a weak storey and change of orientation of columns creates vertical stiffness irregularity and lateral stiffness irregularity in the building which is a form of plan irregularity. Thus,making the building vulnerable to the earthquake forces. This review of past studies aims to find out how does orientation of columns and soft storey affect the seismic parameters such as deflection and time period. The study concludes that the soft storeys are to be provided in upper stories and combined effect of soft storey and column orientation is to be studied by means of software aid to prevent failure of building during earthquakes.

The present day records the greatest usage of unmanned aerial vehicles (UAVs) in civil and military fields. UAVs are experimenting materials with respect to physical and mechanical properties which should have more strength to weight ratio, resistance to buckling, high ultimate tensile strength, less inflammable, low thermal gradient, high resistance to noise, high resistance to vibration, resistant against deteriorative fuels and chemicals, low corrosion, low oxidation, and high fatigue. This paper presents an experimental investigation of mechanical properties of bal-sawood-glass fiber, depron-balsa wood, and depron-glass fiber-balsa wood composites. Tensile, hardness, flexural, and thermal tests of different samples are conducted as per ASTM standards. Depron-glass fiber-balsa wood showed 6 times greater tensile strength and 66% hardness than plain balsa wood. Depron-glass fiber-balsa wood showed 34% greater flexural strength than plain balsa wood.

Energy saving in robotic and mechatronic systems is becoming an evermore important topic in both industry and academia. One strategy to reduce the energy consumption, especially for cyclic tasks, is exploiting natural motion. We define natural motion as the system response caused by the conversion of potential elastic energy into kinetic energy. This motion can be both a forced response assisted by a motor or a free response. The application of the natural motion concepts allows for energy saving in tasks characterized by repetitive or cyclic motion. This review paper proposes a classification of several approaches to natural motion, starting from the compliant elements and the actuators needed for its implementation. Then several approaches to natural motion are discussed based on the trajectory followed by the system, providing useful information to the researchers dealing with natural motion.

Although much progress has been made in the characterization and identification of CD4 functions, its role in mechanical properties of cell membrane remains largely unknown. Here an atomic force microscopy (AFM) was used to investigate the roles of CD4 in the elasticity of the leukemic human Jurkat (clone E6-1) cell membranes. Analysis of the approach force curves with Hertz model for a completely elastic soft sample measured on the selected CD41 and CD4-cells showed that CD41 cell membrane was softer than CD4-one. To confirm that CD4 plays a role in altering cell elasticity, human embryonic kidney 293T cells were transiently trans-fected with wild type (wt) CD4 plasmid before being used in AFM nanoindentation experiments. The results also demonstrated CD4-membrane was stiffer than CD41 one suggesting that CD4 integrated into plasma membrane and altered its mechanical properties. The study gives insights into the role of CD4 on cell membrane mechanical characteristics and might be helpful for development of cell biology and medicine. V C 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 239–244, 2016.

The phenomenon of resonance is prominent upon concurrence of the excitation frequency with the natural frequency of the part or the sub-assembly. The gear train and the housing is susceptible to the detrimental effects of this phenomenon by virtue of its nature of construction. Typically, the housing of the gear train contains gears with points at high speed of operation. For research, the vibration for such a Gear is being considered for this work. Popular machine tool like a lathe is being identified for expanding the application of this work. F.E. Modeling shall be pursued for deriving analytical solution to the problem while physical experimentation would be done to offer inputs to the work and validate the model at the initial phase of work. Hyper Works is being considered as a CAE tool for Pre-processing, Solving and Post processing. The experiment would be performed on the physical setup for the existing/ benchmark case.

Concrete is the most widely used construction material. Among all ingredients of concrete, aggregates form the major portion; further there exists a challenge in attaining the structural light weight concrete utilizing the waste. Among the natural waste coconut shells can suitably replace these natural aggregates. The compression testing on cube and split tensile test on cylinder were performed to authenticate its feasibility. Concrete is reinforced with steel bars to negate its weak tension carrying capacity. However, due to higher cost and non-renewability of steel, nowadays attempts were made to provide a low-cost, sustainable material. The feasibility for the usage of locally procured bamboo as reinforcement is tested to evaluate its Elasticity and ultimate strength. The axial compression test on various columns were performed comparing its axial deformation, Energy absorption capacity, ultimate load, displacement ductility and degradation in stiffness.

Health aspects enforced to ponder a study on asphalt which incorporate rubber crumbs to increase strength and
flexibility of asphalt. Disposal of waste tires is a menace and it’s a serious problem globally because it is not
easily biodegradable as these tires consume large spaces, open burning cause serious problems. By the use of
rubber tires, this scrap is utilized efficiently and reduces the cost of asphalt to produce economical system. The
asphalt is absorbed by the rubber particles which swells at high temperature allowing greater concentration of
liquid asphalt. The partial replacement of crumb rubber in asphalt is 5%, 10%, 15%, and 20% (D05, D10, D15, and
D20). The analysis of incorporated asphalt was done in hot mix asphalt. The generated results showed that the
value for resilient modulus and creep stiffness is more as compared to the conventional asphalt and in the
accumulated strain the values are much lesser which is positive approach.

Energy saving in robotic and mechatronic systems is becoming an evermore important topic in both industry and academia. One strategy to reduce the energy consumption, especially for cyclic tasks, is exploiting natural motion. We define natural motion as the system response caused by the conversion of potential elastic energy into kinetic energy. This motion can be both a forced response assisted by a motor or a free response. The application of the natural motion concepts allows for energy saving in tasks characterized by repetitive or cyclic motion. This review paper proposes a classification of several approaches to natural motion, starting from the compliant elements and the actuators needed for its implementation. Then several approaches to natural motion are discussed based on the trajectory followed by the system, providing useful information to the researchers dealing with natural motion.

Polyacrylamid-guar gum polyblends have been prepared via graft copolymerization of acrylamide onto guar gum using KBrO3/thiourea redox system as initiators. In order to obtain polyblends with suitable viscosity and full total conversion the prepared polyblends were subjected to further treatment with K2S2O8. The amide groups in the polyblends are converted to reactive groups through methylolation with formaldehyde, with a view to obtain reactive polyblends. The feasibility of utilizationof the obtained reactive polyblends as permanent stiffening agents for cotton fabrics was studied. The reactive polyblends (i.e. methylolated polyblends) was then applied to cotton fabrics using the conventional pad-dry-cure method under various conditions. The influence of curing temperature, duration and type of catalysts (i.e., ammonium sulphate (NH4)2SO4 and ammonium chloride (NH4Cl)on the cross-linking reactions between the reactive polyblends in question and the cotton cellulose was investigated. The efficiency of the cross-linking reaction was monitored via determining nitrogen percentages. Evaluation tests on tensile properties (i.e., tensile strength (TS), and elongation at break(EAB), crease recovery angle (CRA), and stiffnessweremade. The results obtained indicate that reactive polyblends, the cotton fabrics under the optimum pad-cure conditions arrived at (3%Nmethylol-PAam- GG, 0.5% (NH4)2SO4; curing temperature 140◦C, and curing time, 5 min) produces fabric having excellent permanent stiffness, superior tensile strength as compared with that of untreated fabric. Tentative mechanisms, including different chemical events that can occur through the whole course of polymerization, methylolation and cross-linking processes, are reported.

Abstract: Both experimental and analytical investigation using ANSYS program have been performed on 2500 mm long with 0.8 mm thick steel core. These cores were placed with #8 diameter rods of Fe 415 as reinforcement and filled with M20 grade self compacting concrete. Concrete Filled Steel Fluted Columns (CFSFT) with and without longitudinal reinforcement. Behaviour of concrete filled steel fluted columns having triangular flutes have been investigated by conducting experiment on thirteen columns. The parameters that have been chosen for the study are L/D ratios of 15, 20 and 25 and the number of reinforcements 3, 4, 5 and 6 of #8. The columns were placed on smooth plates at both ends and the columns were axially loaded and have been analysed for its stiffness and strength which have been presented. The percentage increase in strength from ANSYS specimens were 6.25%, 6.02% and 12.59% respectively. Axial deformation obtained from experiments in stiffness for L/D ratios of 15, 20 and 25 70.61%, 62.69% and 63.18% increased as compared to ANSYS.
Keywords: CFST, CFSFC, SCC, Triangular Flutes, Stiffness, Strength.
Title: Comparison of Experimental values with Analytical Evaluation of Concrete Filled Steel Triangular Fluted Columns for Concentric Load
Author: Dr.B.R Niranjan,  Eramma.H
International Journal of Civil and Structural Engineering Research
ISSN 2348-7607 (Online)
Research Publish Journals

Beam-like structures constructed from many long strands that are constrained rather than bonded together can provide high levels of structural damping through friction between individual strands. This paper describes experimental and numerical studies carried out on square-section metal beams that are aimed at improving understanding of the relationship between construction and performance. The beams used in this study are constructed from lengths of square-section, key steel. The bundle of strands is held together at various compression loads with pre-calibrated clamps. Flexural behaviour of an assembled beam is simulated using standard finite element analysis and simple Coulomb friction at the interfaces. The validity of the assumptions used in the models is confirmed by comparison with three point bend tests on a regular nine strand construction at several different clamp loads. Subsequent numerical studies are used to investigate the effects of increasing the number of strands whilst the overall cross-section of the bundle remains unchanged. It is found that overall stiffness drops and loss factor increases when more strands are used. Interestingly, the energy dissipated by each beam construction is almost the same.

Most tennis strings have a performance rating of almost 10 out of 10 if one can believe
the manufacturers' claims. Laboratory tests of tennis strings provide a different picture.
The test methods and the results of testing 90 different strings are described. This type
of information is needed if players, coaches and stringers wish to make an informed
comparison between different strings, and it is also needed if one wishes to model the
interaction between a tennis racket and a tennis ball.

In the present work, the point kinetics equations are solved numerically using the stiffness confinement method (SCM). The solution is applied to the kinetics equations in the presence of different types of reactivities, and is compared with other methods. This method is, also used to analyze reactivity accidents in thermal reactor at start-up, and full power conditions for control rods withdrawal. Thermal reactor (HTR-M) is fuelled by uranium-235. This analysis presents the effect of negative temperature feedback, and the positive reactivity of control rods withdrawal. Power, temperature pulse, and reactivity following the reactivity accidents are calculated using programming language (FORTRAN), and (MATLAB) Codes. The results are compared with previous works and satisfactory agreement is found.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a dismal survival rate. Persistent activation of pancreatic stellate cells (PSCs) can perturb the biomechanical homoeostasis of the tumour microenvironment to favour cancer cell invasion. Here we report that ATRA, an active metabolite of vitamin A, restores mechanical quiescence in PSCs via a mechanism involving a retinoic acid receptor beta (RAR-b)-dependent downregulation of actomyosin (MLC-2) contractility. We show that ATRA reduces the ability of PSCs to generate high traction forces and adapt to extracellular mechanical cues (mechanosensing), as well as suppresses force-mediated extracellular matrix remodelling to inhibit local cancer cell invasion in 3D organotypic models. Our findings implicate a RAR-b/MLC-2 pathway in peritumoural stromal remodelling and mechanosensory-driven activation of PSCs, and further suggest that mechanical reprogramming of PSCs with retinoic acid derivatives might be a viable alternative to stromal ablation strategies for the treatment of PDAC.

In this paper, the effectiveness of textile-reinforced mortar (TRM) and fiber-reinforced polymer (FRP), as a means of improving the punching behavior of reinforced concrete flat slabs were numerically investigated. Finite element (FE) model using ABAQUS computer program was developed to analyze eight half-scaled slabs, in terms of load-carrying capacity, ductility, stiffness, and crack patterns. These eight specimens were divided into two groups (G1 and G2) with four specimens for each of them. Specimens of G1 was similar to that of G2 in all details but differ in the eccentricity of the applied load. Specimens of G1 were tested with concentric load, while these of G2 were tested with 150 mm eccentricity. For each group, one specimen was built as control (unstrengthened), one was strengthened by FRP-sheet, and the other two was strengthened by TRM-jacket with two different mesh opening (10 and 20 mm). The results obtained from FE analysis showed that the efficiency of TRM in increasing the punching shear capacity of strengthened slabs was less than that of FRP. In addition, the slabs strengthened by TRM showed stiffer behavior than that strengthened by FRP, but lesser ductile. TRM effectiveness was sensitive to the mesh size of the textile. When the mesh size decreased, stiffness was increased and ductility was decreased.