Measurements of Nonlinear Dielectric Constants of Pb(Zr,Ti)O3Thin Films Using a Dynamic Measuring Method

Road markings quality control implies conducting several different tests, of which the most significant are visibility tests comprising daytime and night-time visibility measurements by applying the static or the dynamic measuring method. Although the dynamic test method allows measuring the visibility along the entire road section and thus provides a more complete and objective evaluation of road markings quality compared to the static method, it does not measure daytime visibility, for which both the European and the national directives define the minimum requirements. The purpose of this paper is to examine the correlation between daytime and night-time visibility based on static measurements conducted on state roads in the Republic of Croatia. The correlation analysis determined that the strength of relationship between daytime and night-time visibility, is relatively weak. Despite being relatively weak, the relationship still exists, which was the reason for conducting a further analysis. In the analysis, a unique coefficient was obtained through the ratio of retroreflection value and daytime visibility value for all the measurements. The unique coefficient was basis for development of a model that will be able to calculate the daytime visibility based on the results of the dynamic measurements of road markings night-time visibility. The authors evaluated the model with a t-test and concluded that the accuracy of the model is statistically satisfactory.

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Model for Predicting Road Markings Service Life

The Baltic Journal of Road and Bridge Engineering ◽

10.7250/bjrbe.2019-14.447 ◽

2019 ◽

Vol 14 (3) ◽

pp. 341-359

Author(s):

Dario Babić ◽

Anđelko Ščukanec ◽

Darko Babić ◽

Mario Fiolić

Keyword(s):

Service Life ◽

Measuring Method ◽

Timely Manner ◽

Data Set ◽

Winter Maintenance ◽

The Road ◽

Annual Average Daily Traffic ◽

Dynamic Measuring ◽

Road Marking ◽

Life Prediction Model

Road markings provide drivers with the information necessary for their comfortable and safe journey. To achieve that, they must be visible in all driving conditions, which means that they have to be renewed and maintained in a timely manner. This research aims to develop a model for predicting the service life of paint, thermoplastic and agglomerate cold plastic road markings. The research comprised 5218.00 km (115 roads) of solvent-borne paint road markings, 579.00 km (30 roads) of thermoplastic and 4979.00 km (30 roads) of agglomerate cold plastic road markings. The retroreflectivity of road markings was measured two times (after renewal and after winter) using the dynamic measuring method. Service life prediction model was developed for each material based on factors such as initial retroreflectivity, road marking age and position, annual average daily traffic and winter maintenance activity of the road. Developed models were tested using a new data set, and all three models showed satisfactory accuracy. The application of the model enables road authorities to optimise road-marking maintenance activities, while at the same time, ensuring the level of visibility required by drivers.

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Higher Order Nonlinear Dielectric Microscopy

MRS Proceedings ◽

10.1557/proc-688-c9.9.1 ◽

2001 ◽

Vol 688 ◽

Author(s):

Yasuo Cho ◽

Koya Ohara

Keyword(s):

Depth Resolution ◽

Higher Order ◽

Ferroelectric Materials ◽

Unit Cell ◽

Dielectric Constants ◽

Surface Layers ◽

Nonlinear Dielectric ◽

Microscopy Technique ◽

Cell Thickness

AbstractA higher order nonlinear dielectric microscopy technique with higher lateral and depth resolution than conventional nonlinear dielectric imaging is investigated. The proposed technique involves the measurement of higher order nonlinear dielectric constants, with a depth resolution of down to 1.5 nm. The technique is demonstrated to be very useful for observing surface layers of the order of unit cell thickness on ferroelectric materials.

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Polarization Reversal Anti-parallel to the Applied Electric Field Observed Using a Scanning Nonlinear Dielectric Microscopy

MRS Proceedings ◽

10.1557/proc-784-c6.9 ◽

2003 ◽

Vol 784 ◽

Author(s):

Takeshi Morita ◽

Yasuo Cho

Keyword(s):

Electric Field ◽

Nonvolatile Memory ◽

Intrinsic Property ◽

Measuring Method ◽

Ferroelectric Material ◽

Scanning Probe ◽

Nonlinear Dielectric ◽

Poling Direction ◽

Nonvolatile Memory Devices ◽

Probe Microscope

ABSTRACTIt is well known that spontaneous polarization of ferroelectric material is an intrinsic property applied for nonvolatile memory devices. Poling direction can be reversed in a nanometer size area using the conductive cantilever of a scanning probe microscope. In order to detect nanodots patterns, scanning nonlinear dielectric microscope (SNDM) is superior to piezore-sponse microscope in terms of resolution. In this paper, a real-time measuring method of a poling direction is proposed. Using this method, the domain reversal process was observed and an unexpected phenomenon was found, namely, that the poling directions were aligned antiparallel to the poling electric field. This antiparallel poling reversal took place when the film thickness was more than 350 nm in the case of lithium tantalate. At present, the reason and mechanism of the antiparallel poling reversal are uncertain, although it might be related to the concentrated electric field near the cantilever tip.

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