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Establishing warrant conditions for auxiliary free right-turn lanes is not only a policy concern but an engineering judgment that should be based on sound engineering principles. This paper presents a new methodology for establishing volume warrant conditions for free right-turn lanes on two-lane roadways based on a risk probability of a potential rear-end crash involving a decelerating right-turn vehicle and the immediately following advancing through vehicle. With the assumption of shifted negative exponential distribution of arrival interval and application of compound probability theorem, the risk probability can be expressed as a function of the total approach volume and the percent of right turns. By choosing a desired limiting risk probability, warrant conditions for right-turn lanes can be deduced. The rationality of the proposed methodology was evaluated using field survey data, indicating a fair agreement between the modeled probabilities and the field observations. Thus, the proposed methodology established a rational basis for setting volume warrants for free right-turn lanes on two-lane roadways. In application of the proposed methodology, a set of warrant curves was derived, which can be readily used by an engineer in the decision for installation of a free right-turn lane on two-lane roadways. DOI: 10.1061/(ASCE)0733-947X(2008)134:4(155) CE Database subject headings: Risk management; Collisions; Roads; Intersections; Probability.

Accurate prediction of the pavement crack condition is vital for pavement rehabilitation budget allocation. Due to largely nonlinear surface layer properties, randomness in the cracking mechanism, and the complexities involved with deterministic modeling, deterioration of the pavement crack condition has been more efficiently characterized as a stochastic process with Markov chains being an appropriate and popular modeling technique. However, routine Markov modeling techniques suffer from the shortcomings that the transient probabilities have to be computed only implicitly from extensive historical statistics of crack performance and they are also insensitive to timely variations in pavement condition transition trends. This paper presents a new methodology that involves the use of a recurrent or dynamic Markov chain for modeling the pavement crack performance with time in which the transition probabilities are determined based on a logistic model. This model is compatible with basic Markovian concepts since it only uses the current crack condition data along with other relevant data. It is also capable of continuously updating the transition probabilities in an explicit manner. A case study is performed to compare the newly developed recurrent Markov chain with the currently popular static Markov chain. For this comparison, transition probabilities corresponding to both methods are derived from the State of Florida's pavement condition survey database. It is illustrated how the recurrent Markov chain clearly outperforms the static Markov chain in terms of the forecasting accuracy. Therefore it is concluded that by incorporating the dynamics of crack state transition and randomness experienced with the pavement cracking process, the recurrent Markov chain provides a more appropriate, applicable, and above all, a computationally efficient methodology for modeling the pavement deterioration process with respect to cracks. CE Database subject headings: Stochastic processes; Markov chains; Pavement management; Rehabilitation; Cracking; Predictions; Logistics.

This study estimates the cost of poor institutions using cross-provincial firm investments in China based on its unique land policies. We find that provinces with better institutions attract more firm investment and that institutions are substitutive with land price distortion. Firms with high (low) labor productivity move primarily between provinces with better (inferior) institutions. This stratification effect suggests that a poor institutional environment has dynamic costs, hindering technology diffusion from provinces with good institutions to those with poor institutions. The results imply that it is difficult to achieve industrial upgrades by factor price distortion rather than institutional environment improvements. [ABSTRACT FROM AUTHOR]

Based on the fluorescence quenching effect of citric yellow on GSH-CdTe QDs (GSH: glutathione), the concentration of citric yellow (LY) in soft drink was detected by quantum dot fluorescence quenching method, and the reaction mechanism was analysed. The results showed that: LY could be measured in the range of 1.1–46.2 μg∙mL−1 with a detection limit of 6.7 ng∙mL−1. Combined with the influence of temperature change on fluorescence quenching constant and UV-vis absorption spectrum, it can be seen that this process is a static quenching process. The influence of common interfering species on the LY detection was studied, the results showed that the probe is highly selective and sensitive for the detection of LY. Finally, the optical probe was successfully used for the determination of LY in three kinds of soft drink. [ABSTRACT FROM AUTHOR]

This article focuses on the history of the Returning to Righteousness Army in Dunhuang, founded and lead by Zhang Yichao in China's ninth century. Topics addressed include Chinese medieval military history, the government of Dunhuang from 848-1036, and the relationship between elite and ruling families and the central administration.

On March 31, 2020, an Mw 6.5 earthquake struck near Stanley, Idaho. More than 35% nondouble‐couple component in long‐period point‐source solutions indicate a more complex source than slip on a planar fault. Using an integrative analysis of seismological and geodetic data, we find that the Stanley earthquake ruptured a pair of opposing‐dip faults offset by a 10‐km‐wide step, including an unmapped northern subfault with predominantly strike‐slip faulting and a southern subfault subparallel to the Sawtooth fault with predominantly normal faulting. This converging fault geometry allowed the rupture to traverse a surficial 10‐km‐wide step, which is greater than the limiting dimension (3–4 km) that commonly ceases earthquake ruptures. This study reveals that a composite rupture process with strike‐slip and normal faulting is typical for earthquakes located near the northern boundary of the Centennial Tectonic Belt (CTB), which is distinct from the predominantly normal faulting in the central CTB. Plain Language Summary: The northwest of Stanley, Idaho, is struck by an Mw6.5 earthquake on March 31, 2020, which is the largest event in Idaho since the 1983 Borah Peak earthquake. This event has several intriguing aspects: (1) the epicenter located by USGS is not on a mapped fault and the source region has little historical seismicity over the past 50 years; (2) it predominantly involves strike‐slip faulting, which is inconsistent with the extensional strain accommodated by the closest Sawtooth fault; (3) long‐period point‐source solutions have more than 35% non‐double‐couple components, indicating a more complex source than slips on a planar fault. Based upon an integrative analysis for both seismological and remote sensing data, we prescribe an opposing‐dip two‐fault model to reconcile all observations. The rupture initiated near the USGS epicenter, and then propagated to the southeast about 20 km along the northerner subfault trajectory. When reaching the northwestern terminus of the Sawtooth fault, the rupture changed its original trajectory and moved southwestward, traversing a 10‐km‐wide step‐over. After passing the mapped Sawtooth fault terminus, it propagated to the southeast about 25 km along the southern subfault, which is subparallel to the Sawtooth fault scarp. Key Points: An integrative analysis is applied for the seismological and geodetic data of the 2020 Stanley, Idaho earthquakeWe found that the Stanley earthquake ruptured a pair of opposing‐dip faults offset by a 10‐km‐wide step that narrows with depthThis study reveals that complicated rupture processes appear to be typical for the earthquakes located near the northern Centennial Tectonic Belt boundary [ABSTRACT FROM AUTHOR]

Ephedrine (EH) and pseudoephedrine (PEH), which are chiral enantiomers commonly used clinically, have different pharmacological actions and treatment effects due to their chiral nature. In the presence of Pd2+, the reaction system of Ery B (erythrosin B)‐Pd2+ has a strong resonance Rayleigh scattering (RRS) intensity. Adding EH into this system reduced the RRS intensity, but PEH could not produce this phenomenon. The chiral recognition of these enantiomers could be achieved according to this spectral difference. At the same time, reduction in RRS strength of the reaction system is proportional to the concentration of EH. Under optimized conditions, the linear range is 40–960 ng/ml, and the detection limit is 3.9 ng/ml. A new method for the rapid detection of EH enantiomers can be established. Based on this assay, a new method for the determination of the chiral enantiomers of EH and PEH can be developed. [ABSTRACT FROM AUTHOR]

Crosscorrelation is a classical signal-processing technique that plays an important role in exploration and earthquake geophysics. Seismic velocity estimation utilizes the crosscorrelation between observed and predicted seismic records in traveltime tomography. The crosscorrelation between two stations represents the Green's functions retrieved from ambient noises in passive seismic interferometry. It can be used to estimate the subsurface velocity and amplitude information. The calculation of crosscorrelation usually assumes that the input data are stationary; however, the real seismic data are often non-stationary, due to the presence of multiple wave-modes and background noises. The seismic crosscorrelations often have low signal-to-noise ratio and frequently fail to provide correct information for subsequent processing. To address this problem, we develop a comprehensive technique to reduce contamination and improve the quality of crosscorrelation in the wavelet domain. The new procedure includes the forward wavelet transformation of raw records, the crosscorrelation between wavelet coefficients, single-channel image object detection, multi-channel Kalman-filter object tracking, and inverse wavelet transformation to produce the new crosscorrelation gathers. We effectively remove the unwanted components associated with contaminated wave-modes as the proposed detection and tracking algorithm can accurately extract the target wave-mode. We validate the method for three datasets: a marine streamer survey, a borehole survey, and a broadband dataset from seismology stations. We demonstrate that the proposed method can significantly improve the signal-to-noise ratio of the seismic crosscorrelations, considerably enhancing the quality of the data for subsequent advanced crosscorrelation-based seismic processing. [ABSTRACT FROM AUTHOR]

Rising income inequality and the surge of civil disorder are two important socio-economic phenomena in contemporary China. This article empirically explores the relationship between inequality and the occurrence of mass incidents at the county level. The results show that in counties with higher income inequality, mass incidents tend to happen with a larger probability. Two psychological transmission channels exist: income inequality will make individuals not only feel unhappy and unsatisfied with their lives but also feel unsatisfied with the government, both of which will lead to a larger occurrence possibility of mass incidents. A significant proportion of mass incidents are associated with the encroachment on citizens' economic interests and on the relationship between the public and the government. [ABSTRACT FROM AUTHOR]

The semicircular bending (SCB) test has been commonly used to evaluate the fatigue resistance performance of asphalt concrete (AC) mixtures. In this study, flexible index (FI) was obtained based on the Illinois Flexibility Index Test (I-FIT, AASHTO TP124), which was then correlated with mix design variables, including reclaimed asphalt pavement (RAP) content, nominal maximum aggregate size (NMAS), and binder grade. As part of the SCB test, two notch widths were evaluated as well. As a result, the effect of binder grade on FI is significant at the 0.001 level. For the three binder grades (PG 64-22 and PG 67-22, PG 76-22) tested, the higher binder grade generally results in a higher FI. The effect of NMAS on FI is significant at the 0.05 level. Mixtures with the NMAS of 12.5 mm have a lower FI than those with the NMAS of 9.5 mm. The difference in RAP content (25% versus 30%) did not affect a significant difference on FI, which likely due to the marginal difference of the two RAP content levels tested. The binder content has a significant effect on the resulting FI. Mixtures with a slightly higher binder content would have a significantly higher FI. Based on elasticity analysis, 1% increase in the binder percentage would affect approximately 7.53% increase in FI. Other control variables, including air void percent, void in the mineral aggregate, and void filled with asphalt, were found to be insignificant. This may be attributable to the fact that those variables were controlled during the specimen fabrication and their variances are relatively small. Finally, the effect of notch width is significant at the 0.001 level. The larger notch width (4 mm) resulted in a lower FI compared to the smaller notch width (1.5 mm). [ABSTRACT FROM AUTHOR]

Traditional elastic reverse-time migration (RTM) involves P-/S-wave separation for the source and receiver wavefields, followed by applying the zero-lag cross-correlation imaging condition to produce PP and PS images. In anisotropic media, P-/S-wave decomposition requires a higher memory and computational cost than that in isotropic media. In addition, finite acquisition apertures and band-limited source functions result in unsatisfactory resolutions and amplitudes. To mitigate these problems, we present an elastic least-squares imaging method for tilted transversely isotropic media and apply it to land multicomponent and marine pressure data. Unlike traditional RTM, we use the relative perturbations to the product of density and squared axial (compressional/shear) velocities as reflectivity models ( Δ ln C 33 and Δ ln C 55 ), and estimate them by solving a linear inverse problem. Numerical experiments illustrate that subsurface reflectors can be well resolved in adjoint images for land multicomponent data, because of the presence of both P- and S-waves in seismograms. Least-squares migration helps to further improve spatial resolution and image amplitudes. Since there are no direct S-waves in marine streamer data, adjoint RTM images of Δ ln C 55 are mainly resolved with the converted S-waves and are not as good as those in Δ ln C 33 images. By approximating the Hessian inverse, least-squares migration allows us to take advantage of the weak converted P–S–P-waves and improve the Δ ln C 55 image quality. Numerical experiments for synthetic and field data demonstrate the feasibility and advantage of the proposed least-squares TTI RTM compared with wave-mode separation-based elastic RTM. In field data experiments, we observe that since there are no strong P–S–P converted waves in streamer pressure records from the marine survey, the reflectors in Δ ln C 55 image might be mainly imaged from P-waves due to the amplitude versus offset (AVO) effects. [ABSTRACT FROM AUTHOR]

Laboratory experiments and geodynamic simulations demonstrate that poloidal- and toroidal-mode mantle flows develop around subduction zones. Here, we use a new 3-D azimuthal anisotropy model constructed by full waveform inversion, to infer deep subduction-induced mantle flows underneath Middle America. At depths shallower than 150 km, poloidal-mode flow is perpendicular to the trajectory of the Middle American Trench. From 300 to 450 km depth, return flows surround the edges of the Rivera and Atlantic slabs, while escape flows are inferred through slab windows beneath Panama and central Mexico. Furthermore, at 700 km depth, the study region is dominated by the Farallon anomaly, with fast axes perpendicular to its strike, suggesting the development of lattice-preferred orientations by substantial stress. These observations provide depth-dependent seismic anisotropy for future mantle flow simulations, and call for further investigations about the deformation mechanisms and elasticity of minerals in the transition zone and uppermost lower mantle. The motions of subducted slabs are expected to drive mantle flow around slab edges, however, evidence of deep mantle flow has so far remained elusive. Here, the authors present a Full Waveform Inversion 3-D anisotropy model which allows them to infer deep subduction-induced mantle flows underneath the Mid-Americas and the Caribbean. [ABSTRACT FROM AUTHOR]