Tuning the magnetic properties of iron-filled carbon nanotubes

We tuned the magnetic properties of iron-filled multi-walled carbon nanotubes (Fe@CNTs) by careful manipulation of the synthesis parameters in a two zone furnace. Due to the small dimensions of iron filling in these samples they have some of the highest values of magnetization saturation reported for Fe@CNTs. Magnetic characterization of the Fe@CNTs revealed that their coercivity can be systematically tuned by varying the pyrolysis temperature, whereas the saturation magnetization can be significantly enhanced by optimization of the sublimation temperature. The rate of argon flow is seen to have little influence on either the saturation magnetization or the coercivity. Furthermore, the study of remnant magnetization as a function of time revealed that magnetization decay rates can be considerably varied.     

Simulation analysis of emissions trading impact on a non-utility power plant

Non-utility power plants can competitively participate in open electricity market to reduce operational costs but in the absence of pollution charges or emissions trading such generators are tempted to cause greater pollution for profit maximization. This paper presents a solution that incorporates pollution charges for nitrogen oxides and sulphur dioxide emissions in line with existing national environmental quality standards and a new carbon dioxide emissions trading mechanism. A novel approach has been used for allocation of allowable emissions that favors efficiently fuelled and environmentally friendly operation for maximizing profit. Impact of proposed carbon trading on economical utilization of enormous indigenous coal reserves has been analyzed and determined to be acceptable. Software developed in this paper, harnessing Sequential Quadratic Programming capabilities of Matlab, is shown to be adequate simulation tool for various emissions trading schemes and an useful operational decision making tool for constrained non-linear optimization problem of a non-utility power plant.     

Structural tailoring of molybdenum disulfide by argon plasma for efficient electrocatalysis performance

This article describes the synthesis of molybdenum disulfide (MoS₂) nanowires using chemical vapor deposition (CVD) method. The MoS₂-nanowires converts into micro-flake structures with the help of argon (Ar) plasma for the better hydrogen evolution reaction (HER) activity. The MoS₂-nanowires treated by post-Ar plasma at different time of intervals (20 seconds, 40 seconds, 60 seconds, and 3 minutes). The plasma treatment significantly tailored the structure of pristine MoS₂-nanowires due to which additional active sites were produced at the surface of treated MoS₂. A notable HER activity were achieved by plasma-treated MoS₂. To boost the HER activity up to next level, visible light was used at the time of electrocatalysis which enhanced the electrocatalytic activity almost double, which is evident by the low overpotential (190 mV) at current density of 10 mAcm⁻².     

Compact micromachined infrared bandpass filters for planetary spectroscopy

The future needs of space-based, observational planetary and astronomy missions include low mass and small volume radiometric instruments that can operate in high-radiation and low-temperature environments. Here, we focus on a central spectroscopic component, the bandpass filter. We model the bandpass response of the filters to target the wavelength of the resonance peaks at 20, 40, and 60 μm and report good agreement between the modeled and measured response. We present a technique of using standard micromachining processes for semiconductor fabrication to make compact, free-standing, resonant, metal mesh filter arrays with silicon support frames. The process can be customized to include multiple detector array architectures, and the silicon frame provides lightweight mechanical support with low form factor.     

Antimicrobial resistance and genetic profiling of Escherichia coli from a commercial beef packing plant

The objective of this study was to investigate the extent of antimicrobial resistance and to genetically characterize resistant Escherichia coli recovered from a commercial beef packing plant. E. coli isolates were recovered by a hydrophobic grid membrane filtration method by direct plating on SD-39 medium. A total of 284 isolates comprising 71, 36, 55, 52, and 70 isolates from animal hides, washed carcasses, conveyers, beef trimmings, and ground beef, respectively, were analyzed. The susceptibility of E. coli isolates to 15 antimicrobial agents was evaluated with an automated broth microdilution system, and the genetic characterization of these isolates was performed by the random amplified polymorphic DNA (RAPD) method. Of the 284 E. coli isolates, 56% were sensitive to all 15 antimicrobial agents. Resistance to tetracycline, ampicillin, and streptomycin was observed in 38, 9, and 6% of the isolates, respectively. Resistance to one or more antimicrobial agents was observed in 51% of the E. coli isolates recovered from the hides but in only 25% of the E. coli from the washed carcasses. Resistance to one or more antimicrobial agents was observed in 49, 50, and 37% of the isolates recovered from conveyers, beef trimmings, and ground beef, respectively. The RAPD pattern data showed that the majority of resistant E. coli isolates were genetically diverse. Only a few RAPD types of resistant strains were shared among various sample sources. The results of this study suggest that antimicrobial-resistant E. coli isolates were prevalent during all stages of commercial beef processing and that considerably higher numbers of resistant E. coli were present on conveyers, beef trimmings, and ground beef than on dressed carcasses. This stresses the need for improving hygienic conditions during all stages of commercial beef processing and meatpacking to avoid the risks of transfer of antimicrobial-resistant bacteria to humans.     

A comprehensive review of protein-based carriers with simple structures for the co-encapsulation of bioactive agents

The rational design and fabrication of edible codelivery carriers are important to develop functional foods fortified with a plurality of bioactive agents, which may produce synergistic effects in increasing bioactivity and functionality to target specific health benefits. Food proteins possess considerable functional attributes that make them suitable for the delivery of a single bioactive agent in a wide range of platforms. Among the different types of protein-based carriers, protein–ligand nanocomplexes, micro/nanoparticles, and oil-in-water (O/W) emulsions have increasingly attracted attention in the codelivery of multiple bioactive agents, due to the simple and convenient preparation procedure, high stability, matrix compatibility, and dosage flexibility. However, the successful codelivery of bioactive agents with diverse physicochemical properties by using these simple-structure carriers is a daunting task. In this review, some effective strategies such as combined functional properties of proteins, self-assembly, composite, layer-by-layer, and interfacial engineering are introduced to redesign the carrier structure and explore the encapsulation of multiple bioactive agents. It then highlights success stories and challenges in the co-encapsulation of multiple bioactive agents within protein-based carriers with a simple structure. The partition, protection, and release of bioactive agents in these protein-based codelivery carriers are considered and discussed. Finally, safety and application as well as challenges of co-encapsulated bioactive agents in the food industry are also discussed. This work provides a state-of-the-art overview of protein-based particles and O/W emulsions in co-encapsulating bioactive agents, which is essential for the design and development of novel functional foods containing multiple bioactive agents.     

Improving VLC Data Rate and Link Range Using Commercial Electronic Components

Wireless Personal Communications - Acoustic modem is one of the key elements of an underwater wireless sensor network (UWSN). Compared to a terrestrial wireless sensor network (WSN),...     

Multi-Stage Mach–Zehnder Based Continuously Tunable Photonic Delay Line

Wireless Personal Communications - A multi-stage Mach–Zehnder based integrated continuously tunable optical delay line with a large tunability range, increase transmission bandwidth and the...