Temperature Effect on Frictional Properties of HMA at Different Polishing Stages

Both short-term and long-term variations have been observed in measured friction on pavement surface. These variations have been attributed to different factors, such as traffic, rainfall and temperature. Due to the fact that Hot Mix Asphalt (HMA) pavement surface and rubber tires are viscoelastic materials, it is believed that temperature may affect the measured frictional properties. Some researchers have found this effect to be significant; whereas, others have not. Therefore, the effect of temperature on the measured pavement friction remains to be further studied. This paper provides the results of a laboratory study aimed at evaluating the effect of temperature on the measured frictional properties of the HMA surface. The British Pendulum Tester (BPT) was used to measure friction of HMA surfaces at different polishing stages and different temperatures. Statistical analyses were performed to quantify the effect of temperature on the measured friction numbers. The main conclusion of this paper is that temperature is statistically significant in affecting the measured friction values. However, for agencies who desire to record skid number (SN) at a reference temperature for a long-term monitoring purpose, this paper provides a method for converting SN at a given temperature to the SN at the reference temperature

Hyperbolic P-Y Criterion for Cohesive Soils

Drilled shafts have been frequently used as a foundation to support lateral loads. The p-y method of analysis has been widely used for predicting the behavior of laterally loaded drilled shafts. The existing p-y criteria for cohesive soils are divided into soft or stiff clays, on the basis of a limited number of lateral load test results. Currently, there is no p-y criterion developed for cohesive intermediate geomaterial. In this paper, a hyperbolic equation for p-y curve is presented for cohesive soils and intermediate geomaterials. Based on 3-D FEM simulation results, a new empirical equation is presented for calculating the initial tangent to p-y curve. The proposed hyperbolic p-y criterion is verified by using the results of six full-scale lateral load tests on fully instrumented drilled shafts with diameters ranging from 0.76 m to 1.83 m in the geo-medium ranging from soft clays to intermediate geomaterial. The proposed hyperbolic p-y criterion is shown to be capable of predicting the loaddeflection and bending moments of the laterally loaded shafts for the six cases studied in this paper

Karameh Earth Dam, A Challenging Project

The under construction Karameh dam is situated in the Dead Sea Rift (32.00°N, 35.50°E), the boundary between the Arabian and African-Sinai plates. The primary seismic source contributing to the hazard at the Karameh dam site is the active Jordan Valley fault which extends from the Dead Sea to the Sea of Galilee (from 30.90°N to 32.93°N at a longitude of 35.50°E), with an expected maximum earthquake magnitude of 7.8, and passes under the right abutment of the dam body. This paper presents the analysis of the dam under the earthquake loading. This includes the stability analysis of dam embankment under seismic loading, the expected displacement of the dam body, and the liquefaction potential and its associated displacement. The results of analysis indicate that the dam can resist an earthquake of magnitude 7.8 without catastrophic failure, and the fault rupture will not exceed 4.0 m. Also, liquefaction may occur in the foundation layers, which is expected to result in a crest settlement of 4.4 m

Seismicity of Jordan and Conterminous Countries

An up-to-date seismic hazard maps for Jordan and conterminous areas have been developed based on probabilistic approach. Such maps are intended to show the Peak Ground Acceleration (PGA) with 90% probability of not being exceeded in a life time of 50, 100, and 200 years, respectively. The computer program FRISK was used for estimating the PGA. A suitable attenuation equation reported in the literature, along with up-to-date earthquake catalogue including all the earthquake events that occurred in Jordan and neighboring countries, were considered in this study. Altogether, ten seismic zones as potential of earthquake activities are identified in the assessment of the seismic hazard maps. These are Aqaba Gulf fault, Wadi Araba fault, Dead Sea fault, Northern fault, SE-Mediterranean fault, Farah and Carmel faults, Wadi Sirhan fault, Karak-Fayha fault, Suez Gulf fault, and Cyprus zone fault

Disease transmission models for public health decision making: toward an approach for designing intervention strategies for Schistosomiasis japonica.

Mathematical models of disease transmission processes can serve as platforms for integration of diverse data, including site-specific information, for the purpose of designing strategies for minimizing transmission. A model describing the transmission of schistosomiasis is adapted to incorporate field data typically developed in disease control efforts in the mountainous regions of Sichuan Province in China, with the object of exploring the feasibility of model-based control strategies. The model is studied using computer simulation methods. Mechanistically based models of this sort typically have a large number of parameters that pose challenges in reducing parametric uncertainty to levels that will produce predictions sufficiently precise to discriminate among competing control options. We describe here an approach to parameter estimation that uses a recently developed statistical procedure called Bayesian melding to sequentially reduce parametric uncertainty as field data are accumulated over several seasons. Preliminary results of applying the approach to a historical data set in southwestern Sichuan are promising. Moreover, technologic advances using the global positioning system, remote sensing, and geographic information systems promise cost-effective improvements in the nature and quality of field data. This, in turn, suggests that the utility of the modeling approach will increase over time

Bistability and Oscillations in the Huang-Ferrell Model of MAPK Signaling

Physicochemical models of signaling pathways are characterized by high levels of structural and parametric uncertainty, reflecting both incomplete knowledge about signal transduction and the intrinsic variability of cellular processes. As a result, these models try to predict the dynamics of systems with tens or even hundreds of free parameters. At this level of uncertainty, model analysis should emphasize statistics of systems-level properties, rather than the detailed structure of solutions or boundaries separating different dynamic regimes. Based on the combination of random parameter search and continuation algorithms, we developed a methodology for the statistical analysis of mechanistic signaling models. In applying it to the well-studied MAPK cascade model, we discovered a large region of oscillations and explained their emergence from single-stage bistability. The surprising abundance of strongly nonlinear (oscillatory and bistable) input/output maps revealed by our analysis may be one of the reasons why the MAPK cascade in vivo is embedded in more complex regulatory structures. We argue that this type of analysis should accompany nonlinear multiparameter studies of stationary as well as transient features in network dynamics

A Simple Iterative Algorithm for Parsimonious Binary Kernel Fisher Discrimination

By applying recent results in optimization theory variously known as optimization transfer or majorize/minimize algorithms, an algorithm for binary, kernel, Fisher discriminant analysis is introduced that makes use of a non-smooth penalty on the coefficients to provide a parsimonious solution. The problem is converted into a smooth optimization that can be solved iteratively with no greater overhead than iteratively re-weighted least-squares. The result is simple, easily programmed and is shown to perform, in terms of both accuracy and parsimony, as well as or better than a number of leading machine learning algorithms on two well-studied and substantial benchmarks

Effects of Short-Term Exposure to Diesel Exhaust on the Ecophysiology, Growth, and Fecundity of Soybean (Glycine max (L.) Merr.) and Chicory (Cichorium intybus L.)

Plants growing along roadways are often exposed to vehicle exhaust containing both particulate matter (PM) and various gases that could affect gas exchange and thus plant reproduction. To investigate effects of diesel exhaust exposure on plant ecophysiology, growth, and fecundity, individuals of soybean (Glycine max (L.) Merr.) and chicory (Cichorium intybus L.) were exposed to either exhaust from a diesel generator or ambient air. Exposure occurred daily over a 5-day period (beginning 18 June 2013) using open-top chambers in an agricultural field in southwestern Ohio, United States. Plants were evaluated at 3 times (before, directly after exposure, and following a 5.5-week post-treatment recovery period) for photosynthetic rate (A), stomatal conductance (g), water use efficiency (WUE), stomatal clogging due to PM deposition, and number of nodes. Aboveground biomass, fruit number, mean seed number, and seed mass were measured for soybean after the recovery period. In soybean, A minimally decreased with exposure to diesel exhaust (compared to the control), but an increase in g and a decrease in WUE were detected after the exhaust treatment. Chicory exhibited a relatively low increase in A after the treatment, but there were no clear differences in g or WUE. Growth and fecundity were similar among all soybean plants directly after treatment, but after 5.5 weeks plants exposed to diesel exhaust had increased vegetative biomass while exhibiting no difference in fecundity. These plant species reacted differently to short-term diesel exhaust exposure, suggesting that the impact of diesel exhaust will depend on both the plant species and its physiology

Secrecy capacity of a class of orthogonal relay eavesdropper channels

The secrecy capacity of relay channels with orthogonal components is studied in the presence of an additional passive eavesdropper node. The relay and destination receive signals from the source on two orthogonal channels such that the destination also receives transmissions from the relay on its channel. The eavesdropper can overhear either one or both of the orthogonal channels. Inner and outer bounds on the secrecy capacity are developed for both the discrete memoryless and the Gaussian channel models. For the discrete memoryless case, the secrecy capacity is shown to be achieved by a partial decode-and-forward (PDF) scheme when the eavesdropper can overhear only one of the two orthogonal channels. Two new outer bounds are presented for the Gaussian model using recent capacity results for a Gaussian multi-antenna point-to-point channel with a multi-antenna eavesdropper. The outer bounds are shown to be tight for two sub-classes of channels. The first sub-class is one in which the source and relay are clustered and the and the eavesdropper receives signals only on the channel from the source and the relay to the destination, for which the PDF strategy is optimal. The second is a sub-class in which the source does not transmit to the relay, for which a noise-forwarding strategy is optimal.Comment: Submitted to Eurasip Journal on Wireless Communications and Networking special issue on Wireless physical layer security, Dec. 2008, Revised Jun. 200