High sensitive optode for selective determination of Ni based on the covalently immobilized thionine in agarose membrane

A novel Ni²⁺ optode was prepared by covalent immobilization of thionine, 3,7-diamine-5-phenothiazoniom thionineacetate, in a transparent agarose membrane. Influences of various experimental parameters on Ni²⁺ sensing, including the reaction time, the solution pH and the concentration of reagents were investigated. Under the optimized conditions, a linear response was obtained for Ni²⁺ concentrations ranging from 1.00 × 10⁻¹⁰ to 1.00 × 10⁻⁷ mol l⁻¹ with an R² value of 0.9985. The detection limit (3σ) of the method for Ni²⁺ was 9.30 × 10⁻¹¹ mol l⁻¹. The influence of several potentially interfering ions such as Ag⁺, Hg²⁺, Cd²⁺, Zn²⁺, Pb²⁺, Cu²⁺, Mn²⁺, Co³⁺, Cr³⁺, Al³⁺ and Fe³⁺ on the determination of Ni²⁺ was studied and no significant interference was observed. The membrane showed a good durability and short response time with no evidence of reagent leaching. The membrane was successfully applied for the determination of Ni²⁺ in environmental water samples.     

Simple,fast, and accurate parametric modeling of the coupling and external quality factor for microstrip filter design using active learning method

In the realization step of any microstrip filter according to the required electrical characteristics, coupling factors and external quality factor (Q_ext) are related to the physical parameters of the structure using time consuming full wave simulations. This paper presents a simple, fast, and accurate parametric model of the coupling between the coupled square open loop resonators (SOLRs) and Q_ext of these resonators versus physical parameters of the structure and substrate characteristics utilizing active learning method (ALM). In the modeling process the multi-dimensional functions of coupling factor and Q_ext are broken down into their simpler aspects, their behaviors are extracted and then final model will be constructed by combining these simpler aspects. ALM allows the overall model for coupling factor and Q_ext to be developed through the use of small number of initial data. Once the modeling process is completed it provides a fast and accurate prediction of the required physical parameters for a given coupling factor and Q_ext. Using the constructed model for a distinct SOLR, which its accuracy was validated by comparison with the full wave simulation results a filter was designed and fabricated. Good agreement between measured and simulated response confirms the accuracy of the modeling procedure.     

Adaptive cruise control with stop&go function using the state-dependent nonlinear model predictive control approach

In the design of adaptive cruise control (ACC) system two separate control loops - an outer loop to maintain the safe distance from the vehicle traveling in front and an inner loop to control the brake pedal and throttle opening position - are commonly used. In this paper a different approach is proposed in which a single control loop is utilized. The objective of the distance tracking is incorporated into the single nonlinear model predictive control (NMPC) by extending the original linear time invariant (LTI) models obtained by linearizing the nonlinear dynamic model of the vehicle. This is achieved by introducing the additional states corresponding to the relative distance between leading and following vehicles, and also the velocity of the leading vehicle. Control of the brake and throttle position is implemented by taking the state-dependent approach. The model demonstrates to be more effective in tracking the speed and distance by eliminating the necessity of switching between the two controllers. It also offers smooth variation in brake and throttle controlling signal which subsequently results in a more uniform acceleration of the vehicle. The results of proposed method are compared with other ACC systems using two separate control loops. Furthermore, an ACC simulation results using a stop&go scenario are shown, demonstrating a better fulfillment of the design requirements.     

An automatic approach for artifacts detection and shadow enhancement in intravascular ultrasound images

Intravascular ultrasound (IVUS) is clinically available for visualizing coronary arteries. However, it suffers from acoustic shadow areas and ring-down artifacts as two of the common issues in IVUS images. This paper introduces an approach which can overcome these limitations. As shadow areas were displayed behind hard plaques in the IVUS grayscale images, calcified plaques were first segmented by using Otsu threshold. Then, active contour, histogram matching, and local histogram matching are implemented. In addition, a new modified circle Hough transform is introduced to remove the ring-down artifacts from IVUS images. In order to evaluate the efficacy of this new method in detection of shadow and ring-down regions, 300 IVUS images are considered. Sensitivity of 89% and specificity of 92% are achieved from a comparison in revelation of calcium along with shadow in the proposed method and virtual histology images. Also, area differences of \(5.83 \pm 3.3\) and \(5.65 \pm 2.83\) are obtained, respectively, for ring-down and shadow domain when compared to measures performed manually by a clinical expert.     

Validated Simulation Models for Lateral Response of Bridge Abutments with Typical Backfills

Abutment-backfill soil interaction can significantly influence the seismic response of bridges. In the present study, we provide numerical simulation models that are validated using data from recent experiments on the lateral response of typical abutment systems. Those tests involve well-compacted clayey silt and silty sand backfill materials. The simulation methods considered include a method of slices approach for the backfill materials with an assumed log-spiral failure surface coupled with hyperbolic soil stress-strain relationships [referred to as “log-spiral hyperbolic (LSH) model”] as well as detailed finite-element models, both of which were found to compare well with test data. Through parametric studies on the validated LSH model, we develop equations for the lateral load-displacement backbone curves for abutments of varying height for the two aforementioned backfill types. The equations describe a hyperbolic relationship between lateral load per unit width of the abutment wall and the wall deflection and are amendable to practical application in seismic response simulations of bridge systems.     

Coordinated scheduling of a single machine with sequence-dependent setup times and time-window constraints

In this paper we consider the selection and scheduling of several jobs on a single machine with sequence-dependent setup times and strictly enforced time-window constraints on the start times of each job. We demonstrate how to develop network-based algorithms to sustain the desired work in process (WIP) profile in a manufacturing environment. Short-term production targets are used to coordinate decentralised local schedulers and to make the objectives of specific areas in line with the chain objectives. A wide range of test problems with two different network structures are simulated. The effectiveness, efficiency, and robustness of the proposed algorithms are analysed and compared with an exhaustive search approach.     

Object detetion and image segmentation using texture pressure energy in parametric active contour models

Abstract

In recent years, Active Contour Models (ACMs) have become powerful tools for object detection and image segmentation in computer vision and image processing applications. This paper presents a new energy function in parametric active contour models for object detection and image segmentation. In the proposed method, a new pressure energy called “texture pressure energy” is added to the energy function of the parametric active contour model to detect and segment a textured object against a textured background. In this scheme, the texture features of the contour are calculated by a moment based method. Then by comparing these features with texture features of the object, the contour curve is expanded or contracted in order to be adapted to the object boundaries. Experimental results show that the proposed method has more efficient and accurate segmenting functionality than the traditional method when both object and background have texture properties.     

Dual criterion equivalent linearization approach for yielding structures under earthquake excitation

In order to estimate both maximum displacement and maximum inertia force of bilinear hysteretic system subjected to earthquake motions, an equivalent linearization approach with new effective parameters is presented. Effective mass and effective damping ratio as pair of effective parameters instead of the effective period and effective damping ratio in existing equivalent linear systems are introduced. Two error measures for displacement and inertia force are defined. Error distributions over a two‐dimensional parameter space of effective parameters are analysed, and the parameters are determined through a statistical approach with a dual optimization criterion for displacement and inertia force errors applicable to structural design. Single‐degree‐of‐freedom systems with bilinear hysteretic model; natural periods from 0.1 to 3.0 s; linear damping ratios from 3 to 50%; ductility ratios from 1.5 to 6; and post‐yield slope ratios 0, 0.05, 0.1 are considered. Analytical expressions for the effective parameters, and the ratio of the maximum inertia force to the maximum restoring force as functions of response ductility, elastic damping ratio and natural period of inelastic system are proposed for different site conditions and post‐yield slope ratios. Evaluation of proposed equations is performed, which reveals that the linear parameters lead to permissible error ranges. Copyright © 2010 John Wiley & Sons, Ltd.     

Hydrological Assessment of the 1973 Treaty on the Transboundary Helmand River,Using the SWAT Model and a Global Climate Database

Exploitation of the water resources of the Helmand River has been challenging for Iran and Afghanistan. Debates on this issue finally led to a treaty in 1973 between the two countries, in which a total amount of 26 m³/s water from the Helmand River should be delivered to Iran in a normal (or an above normal) water year. The treaty also specifies that a “normal water year” means the year during which the total volume of water at the hydrometric station of Dehrawud (upstream of the Kajakai Dam) is 5661.7 million cubic meter (MCM). This paper aims to assess the long term hydrological conditions of the Upper Helmand River, to detect the occurrence of any non-stationary process in its streamflow time series and compare the possible changes with the content of the 1973 water treaty. Due to very date scarce situation of this region, the SWAT (Soil & Water Assessment Tool) model and CRU (Climatic Research Unit) global dataset were applied to create the long term time series. The results showed that there has been no significant change in annual mean flows in the Upper Helmand River basin. However, there is a consistent increase in monthly flows from November to February and a decrease of the flows in June and July. The monthly changes can be attributed to an increasing trend in temperature in the study area, earlier snowmelts during winter and less snow pack in summer. The applied methodology of this study is useful to cope with the region’s data scarcity and can be applied for similar studies requiring long term time series of hydrological variables.