Traffic inputs for mechanistic-empirical pavement design guide using weigh-in-motion systems in Alberta

Mechanistic-empirical pavement design guide (MEPDG) uses axle load spectra and the number of axle applications to characterise traffic loads for pavement design. Alberta Transportation installed weigh-in-motion (WIM) systems at six highway locations to characterise traffic loads in Alberta for MEPDG design. Seasonal and regional trends in traffic characteristics of the six WIM sites were investigated and compared with the default values in the MEPDG for the years 2009 and 2010. Truck traffic classification (TTC) and axle load distribution factor (ALDF) for the WIM sites showed deviations from the MEPDG defaults. Seasonal variations were also evident in the distribution of different classes of truck throughout the year. Differences are attributed to cold climate conditions and special truck traffic in Alberta because of local industries. Influence of the differences between site-specific traffic characteristics and the MEPDG defaults on the performance of both flexible and rigid pavements for Alberta conditions was investigated through a sensitivity analysis. It was found that the flexible pavement performance is sensitive to TTC and ALDF, and the rigid pavement performance is most sensitive to ALDF.     

A grasshopper optimizer approach for feature selection and optimizing SVM parameters utilizing real biomedical data sets

Neural Computing and Applications - Support vector machines (SVM) are one of the important techniques used to solve classifications problems efficiently. Setting support vector machine kernel...     

Electrocoalescence of binary water droplets falling in oil: Experimental study

The approaching movement and consequent coalescence of binary water droplets falling in stagnant oil and exposed to an external electric field are investigated using a high speed camera. Different situation of the droplets and electric field intensities are applied in the experiments. The qualitative results of the experimental observations are exhibited through the scaled images of the binary droplets snapshots in milliseconds. Furthermore, different approaching trends of the droplets are presented as quantitative plots and discussed based on the theoretical electrostatic and hydrodynamic models. The effect of the applied voltage amplitude, initial distance of the drop pair, and skew angle of the electric field are investigated. The experimental results prove the electrostatic theories; as acceleration in electrocoalescence demonstrated using a stronger electric field as well as closer distance between the droplets. It was also revealed that the skew angle of the electric field decelerates the electrocoalescence until alignment of the droplets.     

Novel design of a RF-MEMS tuneable capacitor based on electrostatically induced torsion

Micro-Electro-Mechanical System (MEMS) RF switches have been one of the most interesting areas for research and development in the last years. It has been shown that they have an excellent performance in the RF and microwave frequency range and a great effort has been dedicated in designing suitable geometries and structures best suited for switching application. In parallel other devices useful for the construction of complex RF circuits have been proposed and studied. Among these tuneable capacitors are of high interest for a variety of applications. In this paper we present a new electromechanical design for a tuneable capacitor with a totally different shape from usual designs. In particular we try to exploit the effect of the small in-plane force that develops during the polarization of a parallel plate capacitor with partially overlapping plates. First prototype realizations aiming at the development of the electromechanic aspects of the concept are discussed and analyzed and as the first realization showed some problems an improved design is presented.     

Structure–function relationships of fullerene esters in polymer solar cells: unexpected structural effects on lifetime and efficiency

We report both transport measurements and spectroscopic data of polymer/fullerene blend photovoltaics using a small library of fullerene esters to correlate device properties with a range of functionality and structural diversity of the ester substituent. We observe that minor structural changes can lead to significant and surprising differences in device efficiency and lifetime. For example we have found that isomeric R‐groups in the fullerene ester‐based devices we have studied have dramatically different efficiencies. The characteristic lifetimes derived from both transport and spectroscopic measurements are generally comparable; however, some more rapid effects in specific fullerene esters are not observed spectroscopically. It is apparent from our results that each fullerene derivative requires re‐optimization to reveal the best device performance. Furthermore we conclude that a library approach is essential for evaluating the effects of structural differences in the constituent molecules and serves as important device optimization method that is not being currently employed in photovoltaic investigations. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis of CL‐20 by a Greener Method Using Nitroguanidine/HNO3

CL‐20 is a nitramine applied in both explosives and propellants. The traditional nitrolysis of tetraacetyldibenzylhexaazaisowurtzitane (TADB), as the key precursor for the synthesis of CL‐20, requires the use of N₂O₄/HNO₃/H₂SO₄ (so‐called mixed acid) which has its drawbacks, especially at industrial scales. Herein, the nitrolysis of TADB with a one pot method was investigated using nitroguanidine (NQ) and guanidinium nitrate (GN)/HNO₃ as new system for the synthesis of CL‐20. Positive features of these nitro‐debenzylation/nitro‐deacetylation methods include lack of mixed acids, simple work‐up and less hazardous reagents. The maximum yield of reaction (72 %) was obtained under optimized conditions (NQ (3.48 mmol) and TADB (0.58 mmol) in 98 % HNO₃ (5 mL) at 85 °C and 24 h).