Nitrate removal efficiency of bacterial consortium (Pseudomonas sp. KW1 and Bacillus sp. YW4) in synthetic nitrate-rich water

The efficiency of bacterial isolates to reduce nitrate from synthetic nitrate-rich water was tested using a batch scale process. Two efficient nitrate reducing bacterial species were isolated from water samples collected from Kodaikanal and Yercaud lakes. Bacterial analysis of the samples revealed the presence of nitrate reducing bacteria belonging to the genera Pseudomonas, Bacillus, Micrococcus and Alcaligenes. Among the isolates, the consortium of Pseudomonas sp. KW1 and Bacillus sp. YW4 was found to be efficient in nitrate reduction. Influences of various carbon sources, incubation temperature and pH on nitrate reduction from synthetic wastewater were also studied. The results showed a rapid and efficient process of nitrate removal (99.4%) from synthetic wastewater supplemented with starch (1%), inoculated by bacterial consortium (Pseudomonas sp. KW1 and Bacillus sp. YW4) at incubation temperature of 30 degrees C at pH 7. This observation has led to the conclusion that the bacterial consortium was responsible for nitrate removal from synthetic nitrate-rich wastewater.     

Determination of critical network interactions: an augmented Boolean pseudo-dynamics approach

Network theory has established that highly connected nodes in regulatory networks (hubs) show a strong correlation with criticality in network function. Although topological analysis is fully capable of identifying network hubs, it does not provide an objective method for ranking the importance of a particular node by relating its contribution to the overall network response. Towards this end, the authors have developed an augmented Boolean pseudo-dynamics approach to a priori determine the critical network interactions in biological interaction networks. The approach utilises network topology and dynamic state information to determine the set of active pathways. The active pathways are used in conjunction with the key cellular properties of efficiency and robustness, to rank the network interactions based on their importance in the sustenance of network function. To demonstrate the utility of the approach, the authors consider the well characterised guard cell signalling network in plant cells. An integrated analysis of the network revealed the critical mechanisms resulting in stomata closure in the presence and absence of abscisic acid, in excellent agreement with published results.     

Multicarrier spread spectrum watermarking for secure error concealment in fading channel

This paper proposes a novel multicarrier spread spectrum (SS) watermarking scheme for the application of image error concealment using multicarrier-code division multiple access (MC-CDMA) with binary phase shift keying (BPSK) transmission in Rayleigh fading channel. The goal is achieved by embedding important information (image digest) which is extracted from the original image itself, and is used to introduce sufficient redundancy in the transmitted image. Half-toning technique is applied to obtain image digest from its low-resolution version. At the decoder side, data demodulation as well as watermark decoding are done using minimum mean square error combining (MMSEC) strategy. The extracted image digest is used to correct the damaged regions. The integration of SS watermarking with the existing SS modulation not only simplifies the design but also offers significant performance improvement for error concealment in fading channel. Authorized users having the knowledge of code patterns for SS watermarking can only perform the error concealment operation and the method is secured. Experimental results duly support the effectiveness of the proposed scheme.     

Analysis of voltage stability uncertaintyusing stochastic response surface methodrelated to wind farm correlation

Recent advances in battery energy storage technologies enable increasing number of photovoltaic-battery energy storage systems (PV-BESS) to be deployed and connected with current power grids. The reliable and efficient utilization of BESS imposes an obvious technical challenge which needs to be urgently addressed. In this paper, the optimal operation of PV-BESS based power plant is investigated. The operational scenarios are firstly partitioned using a self-organizing map (SOM) clustering based approach. The revenue optimization model is adopted for the PV-BESS power plants to determine the optimal operational modes under typical conditions for a set of considerations, e.g. power generation revenue, assessing rewards/penalties as well as peak shaving/valley filling revenue. The solution is evaluated through a set of case studies, and the numerical result demonstrates the effectiveness of the suggested solution can optimally operate the BESS with the maximal revenue.     

Enhanced enzymolysis of never-dried cotton fibers belonging to different species

Enzymolysis of cotton cellulose in their never-dried state, belonging to all the four cultivated species of cotton, was carried out with the enzyme derived from penicillium funiculosum F₄. Hydrolysis to reducing sugars was almost complete for all the cottons in 6 h, though glucose percentage varied. X-ray characterizations of the residues obtained, which were both after enzyme and acid hydrolysis, showed significant differences between both hydrolyses, as well as differences in the behavior of different cotton fibers towards enzyme action. These differences have been attributed to the different structural organization of cellulose in the secondary cell wall of cotton fibers.     

Upconversion of NaYF4: Yb,Er Nanoparticles Co-doped with Zr 4+ for Magnetic Phase Transition and Biomedical Imaging Applications

Tracking of cancer cells and cytotoxicity of normal tissue are the leading problem in cancer treatment. The magnetic and fluorescent multifunctional particles evolve as an emerging alternative for future target recognition. The ferromagnetic materials potentially treat the defects in the gene. Hence, ferromagnetic materials are the best for the treatment of cancer using gene therapy. Here, β-NaYF₄: Yb, Er compounds doped with 10%, 20% and 30% Zirconium (Zr) are prepared through hydrothermal technique. Citrate itself is a highly biocompatible surface ligand that labels the imaging probe. The X-ray diffraction analysis is evident for transforming hexagonal to cubic phase via Zr doping in NaYF₄: Yb, Er compounds. The electron microscopic images identify the hexagonal plates. This compound can emit visible light in response to infrared (IR) light irradiation. Especially β-NaYF₄: Yb, Er, and 10% of Zr, Yb, Er tridoped NaYF₄ compounds show enhanced red emission exploited in bioimaging applications. Insignificantly, 30% of Zr, Yb, Er tridoped NaYF₄ concentration exhibit hexagonal and dominating cubic (α) phase, could decrease red emissions intensity and magnetisation value. This Zr material reveals peculiar magnetic properties, especially ferromagnetism at a lower magnetic field and produces paramagnetism at a higher magnetic field. Here, 10–20% Zr, Yb, Er tridoped NaYF₄ concentrations exhibit better magnetic properties. The resultant compound is viable for the VERO cells.

     

Radiation induced graft copolymerization of vinyl monomers and their binary mixture onto rayon fibre

Ethyl acrylate (EA), Vinyl imidazole (VI), and their binary mixture have been copolymerized onto rayon in aqueous medium by mutual method using γ-radiation. The graft yield has been determined as a function of different reaction parameters such as total dose, concentration of vinyl monomers, and amount of water. Effect of surfactant (1-octane sulfonic acid, sodium salt) has been studied on the percentage of grafting of EA, VI, and (EA + VI). A plausible mechanism has been suggested to explain the observed behavior of the surfactant on grafting. Water retention and moisture regain of the grafted film was determined at appropriate relative humidity. The graft copolymers have been characterized by IR spectroscopy and scanning electron microscopic methods. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Twisted Crystalline Organic Semiconductor Photodetectors

Optoelectronic properties of anisotropic crystals vary with direction requiring that the orientation of molecular organic semiconductor crystals is controlled in optoelectronic device active layers to achieve optimal performance. Here, a generalizable strategy to introduce periodic variations in the out-of-plane orientations of 5,11-bis(triisopropylsilylethynyl)anthradithiophene (TIPS ADT) crystals is presented. TIPS ADT crystallized from the melt in the presence of 16 wt.% polyethylene (PE) forms banded spherulites of crystalline fibrils that twist in concert about the radial growth direction. These spherulites exhibit band-dependent light absorption, photoluminescence, and Raman scattering depending on the local orientation of crystals. Mueller matrix imaging reveals strong circular extinction (CE), with TIPS ADT banded spherulites exhibiting domains of positive or negative CE signal depending on the crystal twisting sense. Furthermore, orientation-dependent enhancement in charge injection and extraction in films of twisted TIPS ADT crystals compared to films of straight crystals is visualized in local conductive atomic force microscopy maps. This enhancement leads to 3.3- and 6.2-times larger photocurrents and external quantum efficiencies, respectively, in photodetectors comprising twisted crystals than those comprising straight crystals.     

Terahertz Time-Domain Spectroscopy for In Situ Monitoring of Ceramic Nuclear Waste Forms

The use of terahertz time-domain spectroscopy (THz-TDS) is presented as a non-contact method for in situ monitoring of ceramic waste forms. Single-phase materials of zirconolite (CaZrTi₂O₇), pyrochlore (Nd₂Ti₂O₇), and hollandite (BaCs_0.3Cr_2.3Ti_5.7O₁₆ and BaCs_0.3CrFeAl_0.3Ti_5.7O₁₆) were characterized. The refractive index and dielectric properties in THz frequencies demonstrate the ability to distinguish between these materials. Differences in processing methods show distinct changes in both the THz-TDS spectra and optical and dielectric properties of these ceramic phases. The temperature dependence of the refractive index and relative permittivity of pyrochlore and zirconolite materials in the range of 25–200 °C is found to follow an exponential increasing trend. This can also be used to monitor the temperature of the ceramic waste forms on storage over extended geological time scales.