Bioinspired Directional Surfaces for Adhesion,Wetting, and Transport

In Nature, directional surfaces on insect cuticle, animal fur, bird feathers, and plant leaves are composed of dual micro‐nanoscale features that tune roughness and surface energy. Here, experimental and theoretical approaches for the design, synthesis, and characterization of new bioinspired surfaces demonstrating unidirectional surface properties are summarized. The experimental approaches focus on bottom‐up and top‐down synthesis methods of unidirectional micro‐ and nanoscale films to explore and characterize their anomalous features. The theoretical component focuses on computational tools to predict the physicochemical properties of unidirectional surfaces.     

Distributed audio sensing with homeostasis-inspired autonomous communication

Emerging applications of wireless sensor networks (WSN) requiring wide-band event signal communication such as multimedia surveillance sensor networks impose additional challenges including high communication bandwidth requirement and energy cost. Besides their partially or fully dependency on feedback messages from sink node, the existing protocols designed for WSN do not address the communication of wide-band event signals. Furthermore, the feedback messages may not reach in time to provide reliable communication of event information and save scarce network resources. Therefore, an autonomous communication protocol is imperative in order to provide wide-band event signal communication without any feedback from the sink. In nature, biological systems have self-organization capability, i.e., homeostasis, as they autonomously maintain a relatively stable equilibrium state for operation of vital functions. Hence, this natural phenomenon clearly gives promising inspirations in order to develop autonomous and efficient communication models and protocols for WSN domain. In this paper, the homeostasis-inspired autonomous communication (HAC) protocol is introduced for wireless audio sensor networks (WASN). Using the spectral properties of the wide-band event signal, i.e., audio signal, HAC enables WASN to maintain a relatively stable state in which sensor nodes reliably and energy-efficiently communicate the event signal to the sink node. Furthermore, with its self-organization capability, HAC does not rely on any feedback message from the sink node. Performance evaluations reveal that HAC successfully communicates wide-band event signal with minimum energy expenditure.     

River Stage Forecasting Using Wavelet Packet Decomposition and Machine Learning Models

Water Resources Management - This study develops and applies three hybrid models, including wavelet packet-artificial neural network (WPANN), wavelet packet-adaptive neuro-fuzzy inference system...     

Reduction of acrylamide formation in French fries by microwave pre‐cooking of potato strips

In this study, the effect of microwave pre‐cooking of potato strips on the resultant acrylamide levels in French fries was investigated. Control and microwaved (10, 20, and 30 s at 850 W) samples were fried at 150, 170 and 190 °C for predetermined times. Surface and core temperatures of potato strips were acquired during frying, and acrylamide content in the surface and the core regions were determined separately. The results showed that microwave application prior to frying resulted in a marked reduction of acrylamide level in the surface region, whereas a slight increase was noted for the core region. When the potato strips were subjected to frying after a microwave pre‐cooking step, acrylamide content in the whole potato strip was reduced by 36%, 41%, and 60% for frying at 150, 170, and 190 °C, respectively, in comparison to the control. Copyright © 2006 Society of Chemical Industry     

Prediction of effect of natural antioxidant compounds on hazelnut oil oxidation by adaptive neuro-fuzzy inference system and artificial neural network

In this study, natural compounds including gallic acid, ellagic acid, quercetin, β-carotene, and retinol were used as antioxidant agents in order to prevent and decrease oxidation in hazelnut oil. Quercetin showed the strongest antioxidative effect among the antioxidative agents, during storage. The accuracy of adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN) models was studied to estimate the oil samples' peroxide value (PV), free fatty acid (FFA), and iodine values (IV). The root mean square error (RMSE), mean absolute error (MAE), and determination coefficient (R(2)) statistics were used to evaluate the models' accuracy. Comparison of the models showed that the ANFIS model performed better than the ANN and multiple linear regressions (MLR) models for estimating the PV, FFA, and IV. The values of R(2) and RMSE were found to be 0.9966 and 2.51, 0.6269 and 88.55, 0.5120 and 101.8 for the ANFIS, ANN, and MLR models for PV in testing period, respectively. The MLR was found to be insufficient for estimating various properties of the oil samples.     

A Cross-Layer Framework for Association Control in Wireless Mesh Networks

The user association mechanism specified by the IEEE 802.11 standard does not consider the channel conditions and the AP load in the association process. Employing the mechanism in its plain form in wireless mesh networks we may only achieve low throughput and low user transmission rates. In this paper we design a new association framework in order to provide optimal association and network performance. In this framework we propose a new channel-quality based user association mechanism inspired by the operation of the infrastructure-based WLANs. Besides, we enforce our framework by proposing an airtime-metric based association mechanism that is aware of the uplink and downlink channel conditions as well as the communication load. We then extend the functionality of this mechanism in a cross-layer manner taking into account information from the routing layer, in order to fit it in the operation of wireless mesh networks. Lastly, we design a hybrid association scheme that can be efficiently applied in real deployments to improve the network performance. We evaluate the performance of our system through simulations and we show that wireless mesh networks that use the proposed association mechanisms are more capable in meeting the needs of QoS-sensitive applications.     

Thermodynamic assessment of the Al–Ca binary system using random solution and associate models

The thermodynamic properties of the binary Al–Ca system are investigated. The assessment is carried out by means of the computer program Thermo-Calc, using models for the Gibbs energy of individual phases. In the present study, both associate and random solution models are tested for the system to better reproduce the experimental data. The results from the two models are compared with each other and with experimental data in the literature.     

Development of an electromagnetic hydrocyclone separator for purification of wastewater

A number of various organic and inorganic contaminants are commonly present in the technological fluids hindering production quality. Importantly, waste influents must be purified to meet the appropriate environmental standards for their disposal. This paper deals with the development of a treatment technique for technological and wastewater streams allowing the separation of microscopic droplets of water, sand, oil and other organic and inorganic contaminants. Some existing approaches and processes for treatment of contaminated fluids are briefly reviewed and the design of an electromagnetic hydrocyclone separator is presented in this paper. The effect of the main forces on the separation of small‐sized impurities (<10 μm) is analysed. The experimental tests demonstrated the efficiency of the developed apparatus in purifying the industrial wastewaters of the textile dyeing industry.     

Development of an urban health and wellbeing index for work precincts: A comparative study in Sydney,Australia

Work precincts are recognized for their significant role as generators of employment and associated commerce within urban areas. This study describes a method for analyzing the physical characteristics of urban work precincts in promoting the health and wellbeing of their occupants. The following physical parameters are analyzed: public transport accessibility, green and blue spaces, food environments, fitness facilities, supermarkets, and grocery stores. The parameters are assessed using quantitative spatial analysis based on street network data, as well as point of interest data acquired from OpenStreetMap (OSM). The streets and their intersections are stored in the OSM database as links and nodes, respectively. The evaluation of the performance metrics involves measuring the street network distance from each node to the closest node of interest for each parameter. The metrics are then combined, forming an urban health and wellbeing index (UHWI), which can be used to compare the performance of different precincts. The method was tested by investigating four work precincts in Sydney, Australia, all hosting a large office building belonging to the same business institution. Our results identified two of the four precincts with a high UHWI and resulted in the identification of one underperforming precinct.     

Effects of minor Cu and Si additions on glass forming ability and mechanical properties of Co-Fe-Ta-B Bulk metallic glass

Effect of Cu and Si substitutions for Co and B on the glass forming ability (GFA) of Co_(43-x)Cu_xFe₂₀Ta_5.5B_(31.5-x)Si_y (x=0-1.5 and y=5-10) were systematically investigated by X-ray diffraction, optical microscopy, scanning electron microscopy, and differential scanning calorimetry. In order to evaluate the contribution of copper and silicon, appropriate amounts of copper and silicon were individually introduced to the base alloy composition. By using the effects of copper and silicon together, significant enhancement was obtained and the critical casting thickness (CCT) of the base alloy was increased three times from 2 mm to 6 mm. Moreover, mechanical properties of the alloys were examined by compression tests and Vickers hardness measurements. The compression test results revealed that the glassy alloys having enhanced GFA shows high strength of about 3500-4000 MPa. In addition, existence of (Co,Fe)₂B and (Co,Fe)_20.82Ta_2.18B₆ crystalline phases in glassy matrix influences the hardnesses of the alloys compared to monolitic glassy structure having hardness of about 1200 Hv.