Safety evaluation of roadway segments provided with Safety Edge in Iowa

Pavement edge drop-off is the vertical difference in elevation between the paved roadway and the adjacent ground. It is a serious safety concern for vehicles that goes off the track and encounters a drop-off. The errant vehicles, in order to restore their position back on the paved road, exert a greater amount of force which may result in loss of control for the driver. This may indicate an increase in the possibility of lane departure crashes, rollovers or head on collisions. According to an estimation by the Federal Highway Administration about 11,000 people suffers from injuries and about 160 people lose their lives each year in crashes related to unsafe pavement edges in the United States. Safety Edge, on the other hand, is a design feature that creates a fillet along the edge of the pavement of the roadway that allows drivers, who drift off roadways, to return safely to the roads. This study intended to conduct a safety evaluation of road segments provided with Safety Edge in Iowa. Thus a before and after crash analysis was conducted to estimate any reduction in crashes in the after period of installation. This research also looked into the road and traffic characteristics that significantly affected the crashes on road segments provided with Safety Edge. A total length of 483 miles of roadway segments installed with Safety Edge was identified all over Iowa. Roadway, traffic, lane characteristics and crashes on the treatment segments for the study period of eleven years from 2004 to 2011 was obtained from Iowa Department of Transportation. A Preliminary before and after crash analysis for all types of crashes showed a 50% reduction in all types of fatal crashes, 18.5% reduction in all types of property damage only (PDO) crashes and an overall decrease of 19% for all types of total crashes. A preliminary before and after crash analysis for target crashes showed a 75% reduction in Target fatal crashes, 1% increase in target PDO crashes and overall 17% reduction in total target crashes. The crash data which is a form of count data was analyzed using negative binomial regression. Positive safety impact of installation of Safety Edges was observed for almost all the statistical models (except for property damage only target crashes), as the crashes in the after period was observed to be less than that of the before period. Both scenarios of all types of crashes and target crashes were considered separately in the study. The variables that significantly affected the different crash models were average annual daily traffic (AADT), shoulder width, Rural/Urban indicator, and surface width. Negative Binomial Models for All types of KABCO crashes (all crash severity levels taken together) showed 21% reduction in crashes in the after period. The percentage reduction of all types of injury (KABC) crashes was 20%. For all types of PDO crashes the reduction was seen to be again 20%. Negative Binomial Models for target crashes showed 16.3% reduction in target KABCO crashes and 2.4% increase in target PDO crashes, along with 21% reduction in all types of KABCO crashes, and 20 % reduction in all types of PDO crashes. The results indicated that Safety Edge installation may also be able to reduce the severity of a crash

North Indian Classical Music and the West: The Journey from the Realm of Multicultural to Transcultural

In popular and scholarly discourse, the term globalization is widely used to define the way things have shaped up in the contemporary world. The general agreement of the social scientists and researchers today hinges on the concept of a hybrid global culture. While the importance of this hybrid fabric becomes inevitable, cautious attention needs to be exercised towards the fact that the elements of hybridity do not become rigid constituents of an unaccommodating discourse. The inherent nature of this discourse on the one hand runs the risk of generating the constant urge on the part of the participants to modify and fit into this new and over-arching template, while on the other, its growing contemporary relevance might indulge in casting a shadow on the long history of give and take that have existed between cultures for a very long time. This paper suggests that cross-cultural encounters and mutual appropriations have been a regular feature even though they might have come with a cost. In order to have an empirical understanding of such transcultural processes the author has chosen to explore the encounters of North Indian classical music with the West. This is not simply about how Western or Indian musicians have used each other’s elements to give piquancy to their own creations; rather, it is about a wider issue how one culture perceives the cultural products of another and what grows out of it. Music, that most enigmatic form of human expression, seems a suitable subject for understanding this complex cultural process. The paper intends to investigate this by focusing on the experiences of two very eminent personalities, Vishnu Narayan Bhatkhande and Pandit Ravi Shankar whose contributions to their craft have been remarkable as well as controversial

Safety Edge Crash Modification Factors

This study evaluated the safety impact of the Safety Edge for construction projects in 2010 and 2011 in Iowa to assess the effectiveness of the treatment in reducing crashes

Wideband Transfer Function Identification Using MAGVF (Magnitude Vector Fitting) Method

RÉSUMÉ La technique de lissage vectoriel («Vector Fitting»), lorsqu'elle est utilisée avec le modèle universel de ligne (ULM, «Universal Line Model»), sert à identifier les fonctions associées avec les lignes de transport et câbles, soit la fonction matricielle de propagation et l’admittance caractéristique, sous forme de fonctions de transfert dans le domaine fréquentiel. L'un des défis avec cette technique est relié aux calculs complexes requis pour estimer les délais de la fonction de propagation avant d’identifier ses pôles. Cette mémoire examine la technique de lissage vectoriel de magnitude («Magnitude Vector Fitting» ou «magVF») par rapport à la technique de lissage vectoriel dans l'identification des fonctions modales de propagation. Les valeurs propres de la fonction matricielle de propagation correspondent aux fonctions modales de propagation et chacune des fonctions modales est associée avec un délai. Le modèle ULM propose que chacune des fonctions modales de propagation découplées est un système de phase minimum multiplié par un délai constant dans le domaine fréquentiel. La méthode de lissage vectoriel est utilisée pour obtenir la fonction de transfert des fonctions modales en solutionnant deux équations linéaires séquentielles de moindres carrés. Néanmoins, une approche itérative bouclée doit être utilisée afin de trouver un délai adéquat, tout en minimisant l’erreur d’approximation. Alternativement, la technique de lissage vectoriel de magnitude est basé sur la technique de lissage vectoriel mais utilise des fonctions de base symétriques pour effectuer le lissage sur une réponse particulière: carrée de la magnitude.Naturellement, l’effet du délai disparait lors de la construction de la réponse à partir de la carrée de magnitude comme entrée pour le lissage. L'utilisation de la technique de lissage vectoriel de magnitude ne nécessite donc pas l'estimation des délais. Le délai d’une fonction modale peut se trouver suite au lissage en faisant des comparaisons de phase entre la fonction obtenue et la fonction originale. Une fois toutes les fonctions modales de propagation sont identifiées avec une tolérance d’erreur prédéfinie, le modèle ULM permet l'utilisation des pôles et délais pour résoudre un dernier problème de moindres carrés afin d’obtenir les résidus de la matrice de propagation dans le domaine de phase. Afin d’améliorer la qualité et la stabilité d’approximation, une approche de pondération est présentée dans cette étude pour dériver une méthode de lissage vectoriel pondéré de magnitude. Cette étude compare l'algorithme de lissage vectoriel de magnitude avec celui de lissage vectoriel, avec et sans pondération, en faisant des comparaisons en utilisant des vrais données de lignes de transmission. Cette recherche démontre que même si l'algorithme de lissage vectoriel de magnitude élimine le besoin d'estimer les délais avant le lissage, il exige quand même un calcul supplémentaire pour tenir compte des problèmes numériques. Une étape de modification de pôles à l'entrée est proposée dans ce travail afin de soulager les problèmes numériques.Il est observé qu’il est possible d’identifier les fonctions modales de propagation par des fonctions de phase minimum avec la méthode de lissage vectoriel de magnitude; par contre, le lissage vectoriel ne garantit pas des systèmes de phase minimum. Il est aussi démontré que les problèmes numériques sont plus manifestants dans le cas des câbles où la dépendance fréquentielle des paramètres est plus importante et complexe.----------ABSTRACT Vector Fitting (VF), when employed with the Universal Line Model (ULM), can be used for approximating system equations of multi-conductor power transmission lines and cables, by helping to identify the propagation matrices and characteristic admittances. However, one of the challenges posed by this technique is the additional computational logic required to estimate the time-delays associated with the modal propagation transfer functions in the frequency domain, prior to arriving at a suitable estimation for poles and residues.This thesis examines Magnitude Vector Fitting (magVF) as an alternative to VF for the fitting of propagation modes. The ULM employs frequency domain decomposition of n-conductor transmission lines or cables into n-propagation modal propagation functions, each of which has an associated delay. This model proposes that the decoupled modal propagation functions are time-delayed minimum-phase systems in the frequency domain. The VF method is used to fit the individual modal equations in residues-poles form using two sequential linear least-squares problems, but an iterative approach must be employed in order to first establish a suitable time delay while minimizing error in the fitter. Alternatively, magVF is an algorithm based on VF that uses symmetric basis functions to perform least-squares fitting based on a given squared-magnitude response. Any effect from the delays on the phase is cancelled during the construction of the magnitude-squared response used as input for the fitter. Naturally, the effect of the delays disappears during the construction of the magnitude-squared response. Using magVF does not, therefore, require estimation of time-delays before getting a successful magnitude-squared fit. The time delay of a modal propagation function can then be directly identified by comparing the phase of the resulting fit with that of the desired response. Once all modal propagation functions have been fit within a suitable margin of error, then the ULM model allows the discovered poles and time-delays to be used to solve a final least-squares problem to get the residues of the phase-domain propagation matrix.A weighting technique that improves the iterative stability and numerical precision of the magVF algorithm known as Weighted Magnitude Vector Fitting (WmagVF) is presented in this study. This study compares the magVF algorithm with the VF one, with and without weighting, and tested against practical transmission line data. This research demonstrates that although the magVF algorithm eliminates the need for doing time-delay estimation prior to fitting, it does require additional logic for dealing with some problems that can arise numerically, making it difficult to implement for certain cases. An Input Pole Modification (IPM) step is proposed and demonstrated. Details are provided for the algorithms of these methods, and results are presented relative to practical transmission line frequency spectrum data.It is observed that while magVF restricts the resulting propagation mode equation to be minimum-phase, VF does not guarantee minimum-phase systems. It is also shown that numerical problems are more apparent in cable cases, where the frequency dependence of the fitting parameters becomes more important and complex

An improved two-step regioselective synthesis of naphth[1,2,-b]- and naphtha(2, 1-b]oxepin-5-ones

1027-102

Phytoremediation: green to clean environmental heavy metal pollution

Many natural processes and anthropogenic activities lead to the persistent accumulation of non-biodegradable heavy metals in the environment. This contamination further has the potential to enter the food chain by a process called bioaccumulation and further, the concentration of heavy metal raises exponentially from lower to higher trophic levels as it is consumed called biomagnification. With the perspective of the consequences associated with heavy metal toxicity including risks to ecosystem and human health (mutagenic, carcinogenic, and teratogenic), the reclamation of toxic accumulates in soil and water is of paramount importance. Presently, clean-up technologies for heavy metals primarily concentrate on mitigating toxicity using physicochemical and mechanical methods such as soil incineration, excavation, landfilling, soil washing, solidification, and the application of electric fields. However, these are expensive, time-consuming, and also result in destructive changes to soil's physicochemical and biological properties, causing secondary pollution to the soil ecosystem. Therefore, the use of the inherent plant’s ability to absorb ionic compounds even at low concentrations near the soil-root interface can be effectively employed as a strategy to extract and remove or lower the bioavailable toxic metals and this phenomenon is called phytoremediation

Growth of CuCl thin films by magnetron sputtering for ultraviolet optoelectronic applications

Copper (I) chloride (CuCl) is a potential candidate for ultraviolet (UV) optoelectronics due to its close lattice match with Si (mismatch less than 0.4%) and a high UV excitonic emission at room temperature. CuCl thin films were deposited using radio frequency magnetron sputtering technique. The influence of target to substrate distance (dts) and sputtering pressure on the composition, microstructure, and UV emission properties of the films were analyzed. The films deposited with shorter target to substrate spacing (dts=3 cm) were found to be nonstoichiometric, and the film stoichiometry improves when the substrate is moved away from the target (dts=4.5 and 6 cm). A further increase in the spacing results in poor crystalline quality. The grain interface area increases when the sputtering pressure is increased from 1.1×10–³ to 1×10–² mbar at dts=6 cm. Room temperature cathodoluminescence spectrum shows an intense and sharp UV exciton (Z₃) emission at ~385 nm with a full width at half maximum of 16 nm for the films deposited at the optimum dts of 6 cm and a pressure of 1.1×10–³ mbar. A broad deep level emission in the green region (~515 nm) is also observed. The relative intensity of the UV to green emission peaks decreased when the sputtering pressure was increased, consistent with an increase in grain boundary area. The variation in the stoichiometry and the crystallinity are attributed to the change in the intensity and energy of the flux of materials from the target due to the interaction with the background gas molecules