Cue-based networking

In this paper we present a new approach called cue-based networking that uses hints or cues about the physical environment to optimize networked application behavior. We define the notion of cues and describe how cues can be obtained using wireless sensor networks as the underlying platform. We identify both the research and system challenges that need to be addressed to realize benefits of the approach under a target application of video delivery over IP networks. In the process, we identify key challenges of wireless sensor networks, namely timeliness and robustness. We design an adaptive algorithm that balances the tradeoff between them satisfying both timeliness and robustness requirements. Through an implementation of the video delivery application using the proposed algorithm in a real home environment, we highlight the practical benefits of the proposed approach.     

Dynamic constitutive behavior of Hastelloy X under thermo-mechanical loads

An experimental investigation has been conducted to study the dynamic constitutive behavior of Hastelloy X (AMS 5754) at room and elevated temperatures under varying rates of loading. A split Hopkinson pressure bar (SHPB) apparatus was used in conjunction with an induction coil heating system for applying dynamic loads at elevated temperatures. Experiments were carried out at different temperatures ranging from room temperature (25 °C) to 1,100 °C at an average strain rate of 5000/s. Room temperature experiments were carried out at varying strain rates from 1000 to 4000/s. The results show that as the strain rate increases from quasi-static to 4000/s, the yield strength increases by approximately 50%. Also, under dynamic loading, the yield stress decreases with temperature up to 700 °C, after which it shows a peak at 900 °C before beginning to decrease again as the temperature is further increased. The Johnson–Cook model was used to predict the dynamic plastic response under varying rates of loading and at different temperatures.     

Identification of the antibiotic phomalactone from the entomopathogenic fungusHirsutella thompsonii var.synnematosa

Dichloromethane extracts of culture broth from three strains of the entomopathogenic fungusHirsutella thompsonii var.synnematosa were toxic to two species of tephritid fruit fly and inhibited conidial germination in vitro in several other entomopathogenic fungi includingBeauveria bassiana, Tolypocladium spp., andMetarhizium anisopliae. A major metabolite, toxic to apple maggot,Rhagoletis pomonella, and inhibitory to conidial germination inB. bassiana, was isolated and identified as the antibiotic (+)-phomalactone, 6-(1-propenyl)-5,-6-dihydro-5-hydroxypyran-2-one. This is the first biologically active compound of low molecular weight isolated from the genusHirsutella.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.     

Communication scheduling to minimize thermal effects of implanted biosensor networks in homogeneous tissue

A network of biosensors can be implanted in a human body for health monitoring, diagnostics, or as a prosthetic device. Biosensors can be organized into clusters where most of the communication takes place within the clusters, and long range transmissions to the base station are performed by the cluster leader to reduce the energy cost. In some applications, the tissues are sensitive to temperature increase and may be damaged by the heat resulting from normal operations and the recharging of sensor nodes. Our work is the first to consider rotating the cluster leadership to minimize the heating effects on human tissues. We explore the factors that lead to temperature increase, and the process for calculating the specific absorption rate (SAR) and temperature increase of implanted biosensors by using the finite-difference time-domain (FDTD) method. We improve performance by rotating the cluster leader based on the leadership history and the sensor locations. We propose a simplified scheme, temperature increase potential, to efficiently predict the temperature increase in tissues surrounding implanted sensors. Finally, a genetic algorithm is proposed to exploit the search for an optimal temperature increase sequence.     

Preparation and characterization of bio-nanocomposite films based on soy protein isolate and montmorillonite using melt extrusion

The non-biodegradable and non-renewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio-nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). Bio-nanocomposite films based on soy protein isolate (SPI) and montmorillonite (MMT) were prepared using melt extrusion. Effects of the pH of film forming solution, MMT content, and extrusion processing parameters (screw speed and barrel temperature distribution) on the structure and properties of SPI–MMT bio-nanocomposite films were investigated. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used for structural characterization of the films. Properties of the films were determined by tensile testing, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and water vapor barrier measurement. The arrangement of MMT in the soy protein matrix ranged from exfoliated at lower MMT content (5%) to intercalated at higher MMT content (15%). There was a significant improvement in mechanical (tensile strength and percent elongation at break) and dynamic mechanical properties (glass transition temperature and storage modulus), thermal stability, and water vapor permeability of the films with the addition of MMT. The results presented in this study show the feasibility of using bio-nanocomposite technology to improve the properties of biopolymer films based on SPI.     

SML-Sys: a functional framework with multiple models of computation for modeling heterogeneous system

System-on-Chip and other complex distributed hardware/software systems contain heterogeneous components. High-level modeling of such systems require frameworks that provide designers with the ability to express concepts of models of computation (MoC)s as modeling constructs. Many system-level modeling frameworks and corresponding modeling notations such as Ptolemy II and SystemC-H facilitate multi-MoC modeling but are based on imperative programming languages (C++, Java, etc). In such frameworks, the computation and communication aspects between the components of models get intertwined thereby hindering its amenability to formal analysis. In this work, we illustrate function-based semantic definitions of MoCs, which are formulated in a functional framework called SML-Sys. We illustrate through a number of examples how to create system models using this functional programming paradigm.     

Mining metadata for composability of IPs from SystemC IP library

Exploring the design space when constructing a system is vital to realize a well performing design. Design complexity has made building high-level system models to explore the design space an essential but time-consuming and tedious part of the system design. Reduction in design time and acceleration of design exploration can be provided through reusing IP-cores to construct system models. As a result, it is common to have high-level SoC design flow based on IP libraries promoting reuse. However, the success of these would be dependent on how introspection and reflection capabilities are provided as well as what are the interoperability standard defined. This leads to the important question of what kind of IP metadata must be available to allow CAD tools to effectively manipulate these designs as well as allow for a seamless integration and exchange design information between tools and design flows. In this article, we describe our tools and methodology, which allow introspection of SystemC designs, such that the extracted metadata enables IP composition. We discuss the issues related to extraction of metadata from IPs specified in SystemC and show how our methodology combines C++ and XML parsers and data structures to achieve the above.     

Continuous Flow Microwave‐Assisted Processing and Aseptic Packaging of Purple‐Fleshed Sweetpotato Purees

ABSTRACT: Pumpable purees from purple‐flesh sweetpotatoes (PFSP) were subjected to microwave heating using a 60 kW, 915 MHz continuous flow system, followed by aseptic packaging in flexible containers to obtain a shelf‐stable product. Initial test runs were conducted using a 5 kW 915 MHz microwave system to measure dielectric in‐line properties and examine the puree temperature profiles. The results demonstrated uniformity in heating of the puree at sterilization temperatures (>121 °C), and the dielectric constants and loss factors were within the range of published values for orange‐fleshed sweetpotato purees. The pilot‐scale test runs in a 60 kW microwave unit produced shelf‐stable puree packages stable at room temperature. Polyphenolic content of the PFSP purees were evaluated and the results showed that while total phenolics increased (5.9%) and total monomeric anthocyanins slightly decreased (14.5%) with microwave application, antioxidant activity determined by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity and oxygen radical absorbance capacity (ORAC) assays did not significantly change as a result of microwave processing. Color values showed that microwave‐processed samples differed from fresh puree in saturation and hue angle, but not in overall color change. PFSP purees increased in gel strength when microwave processed, packaged, and stored, but the gel could be easily disrupted into flowable purees. Overall, high‐quality retention can be obtained by microwave processing and aseptic packaging of PFSP purees so that they can be used as functional food ingredients.     

Sunflower Acid Oil-Based Production of Rhamnolipid Using Pseudomonas aeruginosa and Its Application in Liquid Detergents

Utilization of industrial waste as substrates for the rhamnolipid synthesis by Pseudomonas aeruginosa is a worthy alternative for conventionally used vegetable oils and fatty acids to reduce the production cost of rhamnolipid. Sunflower acid oil (SAO), a by-product of the oil industry, contains 70% 18:0 fatty acid, with oleic acid as a major component. In this scope, production and analysis of rhamnolipid was successfully demonstrated using SAO as a new substrate. Pseudomonas aeruginosa produced rhamnolipid (a glycolipid biosurfactant) at a maximum concentration of 4.9 g L⁻¹ with 60 g L⁻¹ of SAO in the medium. Structural properties of rhamnolipid biosurfactant are confirmed using thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and fourier transformed infrared spectroscopy (FTIR) analysis. Further surface-active properties of the crude rhamnolipid were evaluated by measuring surface tension and emulsification properties. The synthesized rhamnolipid reduced the surface tension of water to 30.12 mN m⁻¹ and interfacial tension (against heptane) to 0.52 mN m⁻¹. Moreover, rhamnolipid shows the highest emulsification index (above 80%) for vegetable oils. This study confirms the use of SAO as a potential substrate for rhamnolipid production. The synthesized rhamnolipid was incorporated in liquid detergent formulation along with alpha olefin sulfonate (AOS) and sodium lauryl ether sulfate (SLES). The performance properties including foaming and cleaning efficiency of liquid detergent were compared.