Disphar International (Netherlands)

Findings from a four-year monitoring study of the Tensar mechanically stabilised earth (MSE) walls and adjacent roads along the Fujairah Freeway in the United Arab Emirates are presented in this article. The study area covers the mountainous terrain of the ten-lane freeway that connects Dubai on the west to Fujairah on the east coast. Using Synthetic Aperture Radar (SAR) images, the interferometric stacking technique with Persistent Scatterers (PS) was applied to detect and measure the surface displacements of the Tensar walls and adjacent roads. Three specific areas of interest were studied in detail, revealing varying degrees of displacement over the four-year monitoring period, with the largest movements observed in the embankment 550m east of Wall 20. These findings provide valuable insights into the performance and stability of the Tensar MSE walls and adjacent roads, which can inform future design and maintenance decisions for similar infrastructure projects.

Moral is an important thing in a person's character. However, today Indonesian society has experienced many moral setbacks, especially among adolescents. This causes a moral crisis in adolescents. Although the crisis was realized, it was never known empirically about the moral crisis that occurred. This study intends to test the construct validity of the moral character instrument by means of a confirmatory factor analysis approach. The author's moral character instrument is compiled using a Likert model. Participants in this study were junior high and high school students in two different schools with a total of 153 (n = 153). The results of the CFA analysis show that the multidimensional model on moral instruments is declared fit with the data. However, there are several notes regarding the considerable number of invalid statement items on moral instruments.

More than 60% of accidents in Iran occur within 30 kilometers of cities entrance roads. Therefore the number of accidents per kilometer in these regions, in contrast to the other parts of roads is very considerable. The city of Tehran, as the capital of Iran, is the cross point of major arterials of passenger and freight transportation. Thus the evaluation of road safety, entering and exiting the city in the 30 kilometers buffer, can be considered to improve countrywide road safety. To investigate the effects of roadway characteristics and traffic conditions, including number of traffic violations, on accident frequency within 30 km of Tehran entrance roads, Poisson and Negative Binomial regression model were calibrated in this study. Although the goodness of fit index in Poisson model is much greater than the Negative Binomial model, the accident data dispersion in this study implies that Negative Binomial model is more appropriate to show the influences of effective variables. According to results of modeling, the variables including average daily volume, share of heavy vehicles, average daily speed violations and number of direct accesses and interchanges have effective influence on accident frequencies. Controlling access to roads and using effective actions to reduce the speed and number of speed violation can be accounted as effective policies to reduce accident frequencies within 30 km of Tehran entrance roads.

DETERMINING THE CRITICAL VELOCITY OF GRASS SODS FOR
 WAVE OVERTOPPING BY A GRASS PULLING DEVICE
 Roel Bijlard, Delft University of Technology, roelbijlard@gmail.com
 Gosse Jan Steendam, INFRAM International, gosse.jan.steendam@infram.nl
 Henk Jan Verhagen, Delft University of Technology, h.j.verhagen@tudelft.nl
 Jentsje van der Meer, Van der Meer Consulting bv, jm@vandermeerconsulting.nl
 
 INTRODUCTION
 There is a shift in the approach for designing coastal
 structures in the Netherlands, such as dikes or levees.
 In the past dikes were designed on the probability of
 exceedance of the water level during specific incoming
 (wave) storm conditions. In the near future the design
 criterion will be the probability of flooding of the
 hinterland. In order to determine this flood probability,
 the strength of the dike has to be known at which
 failure occurs. During extreme storm conditions waves
 will overtop the crest which can lead to erosion of the
 grass sod on the landward slope. This can finally result
 in instability of the dike and flooding of the hinterland.
 Past research focused on the erosion of the grass sod
 during different wave overtopping conditions, see
 Steendam 2014. The last few years many tests have
 been performed with the Wave Overtopping Simulator.
 During these tests the Cumulative Hydraulic Overload
 Method has been developed, see Van der Meer 2010
 and Steendam 2014. With this method an estimation
 of the critical velocity of the grass sod has to be made.
 The critical velocity is a strength parameter for a grass
 sod on a dike during loads induced by overtopping
 wave volumes.
 
 SOD PULLING TESTS
 For safety assessments it would be beneficial if there
 is also an easier way to determine the critical velocity
 of the grass sod. However, it is important to measure
 the actual strength of the grass cover, so a visual
 inspection cannot be satisfactory. The sod pulling
 test is developed in order to investigate the
 resistance of the grass cover. It lifts the grass sod
 perpendicular to the slope out of the sod and
 measures the force as a function of the deformation.
 In order to lift the sod, a pull frame is anchored into
 the top layer with pins. This frame then is lifted out of
 the grass sod by a hydraulic cylinder.
 In order to insert the pins into the sod, the soil has to
 be excavated on two sides (condition 2 test) or on all
 4 sides (condition 4 test). This has the disadvantage
 that the strength of an intact sod cannot be
 measured directly. So a methodology is developed to
 estimate the strength of an intact grass sod from the
 measured data. A further introduction on the sod
 pulling tests is given in Steendam 2014. The goal is
 to rewrite the measured forces from the sod pulling
 test into a critical velocity so that the Cumulative
 Hydraulic Overload Method can be used for
 determining the flooding probability of a dike.
 Some of the locations tested with the wave
 overtopping simulator have also been tested for the
 strength of the grass cover with the sod pulling tests.
 The two methods use the same failure mechanism of
 the grass, erosion of the grass sod.
 The top layer of a dike consists of soil and roots
 growing in multiple directions. The roots anchor the
 grass into the soil and can deform centimeters
 without tearing. Pressures acting on the grass cover
 will first break the weakest roots, but the forces will
 be redistributed to other roots. Only when a critical
 amount of roots are broken, the redistribution stops
 and the grass cover will fail.
 
 CONCLUSION
 It is possible to rewrite the measured forces with the
 sod pulling tests into a critical grass normal stress
 (σgrass.c), which is one of the input parameters for
 determining the critical velocity of a grass sod, see
 Hoffmans 2012.
 
 The equation also uses the pore water pressure (pw),
 the relative turbulence intensity (r0) and the density of
 the water (ρ). When the critical velocity resulting from
 this equation is compared with the determined critical
 velocity during the wave overtopping simulations,
 there is good correspondence between the values for
 the five tested locations. So the sod
 pulling test could provide results that are reliable
 enough to determine the critical velocity of a dike
 section. Further elaboration and scientific background
 will follow in the paper after the conference.
 
 REFERENCES
 Hoffmans (2012): The influence of turbulence on soil
 erosion. Eburon, Delft.
 Steendam, van Hoven, van der Meer, Hoffmans
 (2014): Wave Overtopping Simulator tests on
 transitions and obstacles at grass covered slopes of
 dikes, proc. ICCE 2014 Seoul.
 Van der Meer, Hardeman, Steendam, Schüttrumpf,
 Verheij (2010): Flow depths and velocities at crest
 and inner slope of a dike, in theory and with the Wave
 Overtopping Simulator, Proc. ICCE 2010, Shanghai.

IntroductionRheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease, for which the introduction of injectable treatments has had a major impact on quality of life directly related to the disease. The purpose of this descriptive study was to evaluate the usability of a new autoinjector, intended for methotrexate self-administration, based on the device’s design and instructions for use (IFU).MethodsThis multicenter trial included three user groups: a group of patients with established RA subdivided into two groups according to their hand disability, and a group of caregivers or nurses. Each subject performed three simulated injections with a water-filled device on a foam pad. The first injection was made just after reading the IFU without further instructions (first phase). The second phase consisted of two injections made after explanations provided upon request of the subject in an optimum environment and in a “worst-case” home environment. The usability of the autoinjector was assessed by a questionnaire (success: ≥75% of positive responses) and by a score card reflecting injection performances (success: execution of ≥75% of handling steps).ResultsForty-two subjects were enrolled in the study. During the first phase, the great majority of subjects succeeded in the usability questionnaire (90.5%) and in the injection performance (95.2%) with no major differences between the user groups. In the Second phase, all subjects from all three user groups succeeded in the usability questionnaire and had a positive rate of device handling, regardless of the environment and of the user group. No safety concerns were raised during the study.ConclusionsThis study found a very high level of usability and subject acceptance of the autoinjector, intended for methotrexate self-administration, regardless of the hand disability and environmental conditions.FundingNordic Group.Trial RegistrationEudraCT reference number: 2014-A0141245.

Objective To describe and examine the variations in the plasma concentration-time curves and pharmacokinetic parameters of mesalazine and its metabolite acetylmesalazine after administration of a 500mg gastroresistant tablet.