The effect of TiC transient layer on a DLC-based functionally gradient coating prepared by closed field unbalanced magnetron sputtering plating system

Recently, Diamond like carbon (DLC)-based functionally gradient coatings have been used in a variety of engineering applications as useful films with appropriate tribological properties verified in many tests. However, due to their inherent residual stresses, they have a tendency to peel off, thereby limiting their applications (involving high contact stresses) and deposition thickness. Their brittleness and low adhesion may stem from either a faulty layer design or the wrong choice of material and deposition method. Therefore, using both a suitable interleaving material and an appropriate deposition technology will create an inclusive vision to accommodate better film properties. In this study, Ti-a:C and Ti-TiC-a:C films on AISI M2 steel substrates were deposited by Closed Field Unbalanced Magnetron Sputtering (CFUBMS) method using pulsed-dc biasing, and the mechanical, the structural, and the tribological properties for both films were investigated. It was seen that the incorporation of a TiC buffer layer between the Ti interlayer and the a:C matrix played a positive role in terms of hardness, wear rate, and adhesion properties.     

Light detection and ranging measurements of wake dynamics part I: one‐dimensional scanning

The vast majority of wind turbines are today erected in wind farms. As a consequence, wake‐generated loads are becoming more and more important. In this first of two parts, we present a new experimental technique to measure the instantaneous wake deficit directly, thus allowing for quantification of the wake meandering, as well as the instantaneous wake expansion expressed in a meandering frame of reference. The experiment was conducted primarily to test the simple hypothesis that the wake deficit is advected passively by the larger‐than‐rotor‐size eddies in the atmospheric flow, and that the wake at the same time widens gradually, primarily because of mixing caused by small‐scale atmospheric eddies. In this first paper, we focus on our new measurement technique, and test if the wake meandering follows the wind direction fluctuations, i.e. if it is advected passively in the lateral direction. The experimental results are used as a preliminary verification of a wake meandering model that essentially considers the wake as a passive tracer. Copyright © 2009 John Wiley & Sons, Ltd.     

Light detection and ranging measurements of wake dynamics. Part II: two‐dimensional scanning

A nacelle‐mounted lidar system pointing downstream has been used to measure wind turbine wake dynamics. The new measurement and data analysis techniques allow estimation of quasi‐instantaneous wind fields in planes perpendicular to the rotor axis. A newly developed wake tracking procedure delivers the instantaneous transversal wake position which is quantitatively compared with the prediction of the Dynamic Wake Meandering model. The results, shown for two 10‐min time series, suggest that the conjecture of the wake behaving as a passive tracer is a fair approximation; this corroborates and expands the results of one‐dimensional measurements already presented in the first part of this paper. Consequently, it is now possible to separate the deterministic and turbulent parts of the wake wind field, thus enabling capturing the wake in the meandering frame of reference. The results correspond, qualitatively and to some extent quantitatively, to the expectations from CFD simulations which are compared in the paper. Copyright © 2010 John Wiley & Sons, Ltd.     

Bridge management in Turkey: a BMS design with customised functionalities

The overall design and customised functionalities of a bridge management system (BMS), developed in Turkey in 2009–2013 period (the so-called KYS), are presented. The novel design features are explained. Development of the web-based BMS involved the establishment of a bridge inventory database, a detailed multi-layer cost database with an itemised unit cost breakdown capability, inventory management, cost and planning modules, optimal allocation of maintenance-repair–replacement (MR&R) budgets while producing repair cost estimates at damage level, a network-level multi-criteria prioritisation implementation, establishment of a damage-level condition evaluation and rating model, 13 separate customised functionalities, and visual inspections and data entry for a pilot group of 200 bridges. Matrices containing bridge types versus element types and element types versus damage types are constructed. For each element, a dynamic list is developed that can expand or contract depending on an element's damage types. A check mark-based interactive decision-making capability is built, by which the user can overwrite the recommended decisions. BMS is being used by the bridge administration. Out of a total of 7514 bridges in Turkey, in 2014, the damage-level inspection data of over 3000 bridges is entered into the inventory. Entry of bridge and inspection data for the remaining bridge stock will be completed in 2015.     

Preparation and characterization of polyaniline/Turkish Huntite‐hydromagnesite composites

The aim of this study was to improve thermal stability of polyaniline (PANI) by adding Turkish Huntite. PANI was synthesized and PANI/Turkish Huntite composites were prepared by adding various proportions of huntite to aniline. The chemical structures of the samples were investigated by Fourier transform infrared spectroscopy. Thermal properties of the composites were determined by thermogravimetric analysis and differential scanning calorimetry. The surface morphologies of the samples were investigated by a scanning electron microscopy. The obtained results proved that the composite system is more thermally stable than the pure PANI. POLYM. COMPOS., 35:456–460, 2014. © 2013 Society of Plastics Engineers     

TENET: a new hybrid network architecture for adversarial defense

International Journal of Information Security - Deep neural network (DNN) models are widely renowned for their resistance to random perturbations. However, researchers have found out that these...     

Adversarial security mitigations of mmWave beamforming prediction models using defensive distillation and adversarial retraining

International Journal of Information Security - The design of a security scheme for beamforming prediction is critical for next-generation wireless networks (5G, 6G, and beyond). However, there is...     

The experimental and numerical investigation on thermal responses of passive thermal protected batteries in different packs from low to high discharge rates

Journal of Mechanical Science and Technology - This study contains experimental and numerical investigation of the shape effect of the pack on the performances of PCM (or GNP/PCM) based passive...