Freezing-point-blackbody radiation sources for the 29.78-1084.62 °C temperature range

Freezing points of In, Sn, Zn, Al, Ag, Au, and Cu, along with the melting point of Ga, are among the defining fixed points of the International Temperature Scale of 1990. Accordingly blackbody sources have been commercially produced that utilize the freezing/melting points of the above metals for precision radiometric calibrations of noncontact thermometers. The cavity emissivity is estimated to be 0.999, and the fixed point metals have a nominal purity of 99.9999%. We analyze the freezing plateau of a Au freezing point blackbody and show that the accuracy of calibrating a narrow-band radiometer at 960 nm is (-0.17 ± 0.02) K.     

An integrated perturbation analysis and Sequential Quadratic Programming approach for Model Predictive Control

Computationally efficient algorithms are critical in making Model Predictive Control (MPC) applicable to broader classes of systems with fast dynamics and limited computational resources. In this paper, we propose an integrated formulation of Perturbation Analysis and Sequential Quadratic Programming (InPA-SQP) to address the constrained optimal control problems. The proposed algorithm combines the complementary features of perturbation analysis and SQP in a single unified framework, thereby leading to improved computational efficiency and convergence property. A numerical example is reported to illustrate the proposed method and its computational effectiveness.     

Study of fault location effect on the inter-area oscillations in stressed power systems using modal series method

Heavily loaded, stressed power systems exhibit complex dynamic behavior such as auto and hetero parametric resonances and inter-area oscillations when subjected to a disturbance. These behaviors cannot be analyzed by conventional linearization-based methods. Nonlinear tools, such as normal form and modal series methods can be utilized for studying and understanding these complex behaviors. In this paper, using modal series technique, the effect of fault location and duration on the dynamic performance of stressed power systems is investigated. Three indices are defined and used to explain the effect of different fault scenarios on the transient behaviors of the system. Also, a qualitative analysis of plant mode and inter-area mode type behaviors are presented and typical differences are highlighted. The numerical simulations on the IEEE 50-Generator test system demonstrate validity of the study carried out by modal series analysis.     

Image denoising in undecimated dual-tree complex wavelet domain using multivariate t-distribution

Multimedia Tools and Applications - Denoising of natural images is a basic problem in image processing. The present paper proposes a new algorithm for image denoising based on the maximum...     

Frequency‐dependent behavioral‐model‐based nonlinear analysis and design of a low‐profile transmit active phased array antenna

Design and behavioral‐model‐based nonlinear analysis of a 3‐GHz active‐phased array antenna (APAA) are presented. Four nonlinear power amplifiers are employed in the output ports of the feeding network (FN) and analyzed based on a 5‐order polynomial model with frequency‐dependent coefficients. The FN is based on 4‐port new Gysel power dividers and combiners arranged in such a way to feed the array with Gaussian‐like amplitude and in‐phase distributions. Beam steering capability is obtained in 2 directions by a new technique including a phase shifter and an amplitude controller (AC). The features result in a low‐profile APAA whose design and fabrication complexity and cost are reduced. Single and 2‐tone power tests are performed to develop analytical expressions in nonlinear region for array factor as a function of the model, FN and the phase and ACs. A similar system with frequency‐independent model is also analyzed for comparison in terms of scan loss, beamwidth, side‐lobe level, beam position, and gain. A microstrip array antenna including the power amplifiers, pre‐amplifiers, AC, delay‐line‐based phase shifters and Gysels is fabricated and measured. The simulation results at the single and dual tones and the intermodulation products are presented which have a good agreement with the measurements.     

State of the art: Lateral flow assays toward the point-of-care foodborne pathogenic bacteria detection in food samples

Diverse chemicals and some physical phenomena recently introduced in nanotechnology have enabled scientists to develop useful devices in the field of food sciences. Concerning such developments, detecting foodborne pathogenic bacteria is now an important issue. These kinds of bacteria species have demonstrated severe health effects after consuming foods and high mortality related to acute cases. The most leading path of intoxication and infection has been through food matrices. Hence, quick recognition of foodborne bacteria agents at low concentrations has been required in current diagnostics. Lateral flow assays (LFAs) are one of the urgent and prevalently applied quick recognition methods that have been settled for recognizing diverse types of analytes. Thus, the present review has stressed on latest developments in LFAs-based platforms to detect various foodborne pathogenic bacteria such as Salmonella, Listeria, Escherichia coli, Brucella, Shigella, Staphylococcus aureus, Clostridium botulinum, and Vibrio cholera. Proper prominence has been given on exactly how the labels, detection elements, or procedures have affected recent developments in the evaluation of diverse bacteria using LFAs. Additionally, the modifications in assays specificity and sensitivity consistent with applied food processing techniques have been discussed. Finally, a conclusion has been drawn for highlighting the main challenges confronted through this method and offered a view and insight of thoughts for its further development in the future.     

Possibilities of urban flood reduction through distributed-scale rainwater harvesting

Urban flooding in Chittagong City usually occurs during the monsoon season and a rainwater harvesting(RWH) system can be used as a remedial measure. This study examines the feasibility of rain barrel RWH system at a distributed scale within an urbanized area located in the northwestern part of Chittagong City that experiences flash flooding on a regular basis. For flood modeling, the storm water management model(SWMM) was employed with rain barrel low-impact development(LID) as a flood reduction measure. The Hydrologic Engineering Center's River Analysis System(HEC-RAS) inundation model was coupled with SWMM to observe the detailed and spatial extent of flood reduction.Compared to SWMM simulated floods, the simulated inundation depth using remote sensing data and the HEC-RAS showed a reasonable match,i.e., the correlation coefficients were found to be 0.70 and 0.98, respectively. Finally, using LID, i.e., RWH, a reduction of 28.66% could be achieved for reducing flood extent. Moreover, the study showed that 10%e60% imperviousness of the subcatchment area can yield a monthly RWH potential of 0.04 e0.45 m~3 from a square meter of rooftop area. The model can be used for necessary decision making for flood reduction and to establish a distributed RWH system in the study area.     

Materials Displaying Neural Growth Factor Gradients and Applications in Neural Differentiation of Embryoid Body Cells

The critical growth factor density required to support neural lineage generation from mouse embryonic stem cells is assessed by constructing a surface density gradient of immobilized nerve growth factor (NGF) from a plasma polymer film base. A chemical surface gradient varying from high hydroxyl group density to high aldehyde group density is prepared through diffusion‐controlled plasma polymerization of two monomers (ethanol and propionaldehyde) under a moving mask. NGF density gradients are then produced by reductive amination with the aldehyde groups on the plasma polymer surface. Mouse embryoid body derived (mEB) cell differentiation on the gradient surface is evaluated by immunofluorescence staining against Nestin. mEB cell density and the percentage of Nestin‐positive cells increase with increasing NGF density up to a critical value corresponding to 52.9 ng cm^?2, above which cell attachment and differentiation do not increase further. This gradient‐based screening approach allows the growth factor surface densities to be optimized for biomaterials intended for cell differentiation or expansion, which is highly relevant to creating efficient manufacture processes for cell therapies.     

RQL: a recursive query language

Different classes of recursive queries in the relational databases are identified. It is shown that existing proposals to extend the relational query languages are either not powerful enough to express queries in many of these classes or use nonfirst normal form constructs. RQL, a recursive database query language that can be used to express recursive queries on all the classes identified, is presented. RQL is based on the relational algebra. In addition to functions that correspond to the standard and extended relational algebra operators, RQL supports functions required to express general recursive queries. The elements of RQL and the ways in which they are used to formulate complicated, but useful, recursive queries are described. The effects of the extensions embodied in RQL on the termination of recursive query evaluation are discussed