Fabrication of Functional Nanofibrous Ammonia Sensor

A nanofibrous sensor for ammonia gas is fabricated by electrospinning the composite of poly(diphenylamine) (PDPA) with poly(methyl methacrylate) (PMMA) onto the patterned interdigit electrode. The composite electrospun membrane shows interconnected fibrous morphology. Functional groups in PDPA and the high active surface area of the fibrous membrane make the device detect a lower concentration of ammonia with a good reproducibility. The sensing capability of the device is studied by monitoring the changes in resistance of the membrane with different concentrations of ammonia. The changes in resistance of the membrane shows linearity with the concentration of ammonia in the limit of 10 and 300 ppm. UV-visible spectroscopy reveals the mechanism of sensing ammonia by the membrane.     

Antioxidant capacity and phenolic content of different solvent extracts from banana (Musa paradisiaca) and mustai (Rivea hypocrateriformis)

In the present study, chloroform, acetone, and methanol extracts from stem and flower of banana (Musa paradisiaca) and leaves, stem, and flowers of mustai (Rivea hypocrateriformis) were evaluated for their in vitro antioxidant activity using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH^•), 2,2′azinobis (3-ethylbenzothiozoline-6-sulfonic acid) diammonium salt (ABTS^•+), iron chelation, and antihemolytic activity. Among the solvents used, methanol gave the maximum yield in banana, whereas in night glory acetone was reported to having higher extractive value. The total phenolic content was also higher in these extracts. The antioxidant potential of the extracts was well established with their DPPH^• and ABTS^•+ radical scavenging activities and ferric reducing antioxidant capacity. The potential of multiple antioxidant activity of samples can be further evidenced by inhibition of reactive oxygen mediated erythrocyte cell lysis and metal ion chelating activity. However, this is the first report on the antioxidant property of mustai and this plant is having excellent antioxidant potential over banana. In conclusion, the results implied that the leaves, stem, and flowers of banana, and mustai could be considered as health supplements and nutraceuticals/functional foods.     

Silver nanoparticles distributed into polyaniline bridged silica network: A functional nanocatalyst having synergistic influence for catalysis

A novel organic–inorganic hybrid nanocatalyst, Ag nanoparticles supported poly[N-(3-Trimethoxy silyl)propyl]aniline (Ag@PTMSPA), was prepared by a simple one-step method. X-ray diffraction analysis, field emission transmission electron microscopy and X-ray photo electron spectroscopy reveal the coexistence of Ag nanoparticles (average size ∼ 10 nm) and PTMSPA in Ag@PTMSPA. N₂ adsorption–desorption experiments provide the textural properties of the catalyst, such as surface area (86.6 m²/g), pore volume (1.3 × 10^− 1 cm³/g) and pore size (4.2 nm). UV–visible spectroscopy was used to follow the kinetics of reduction of 4-nitrophenol (4-NP) by sodium borohydride (NaBH₄) in the presence of Ag@PTMSPA catalyst.     

Synthesis of Amido‐N‐imidazolium Salts and their Applications as Ligands in Suzuki–Miyaura Reactions: Coupling of Hetero‐ aromatic Halides and the Synthesis of Milrinone and Irbesartan

A new catalytic system based on palladium‐amido‐N‐heterocyclic carbenes for Suzuki–Miyaura coupling reactions of heteroaryl bromides is described. A variety of sterically bulky, amido‐N‐imidazolium salts were synthesized in high yields from the corresponding anilines. This catalytic system effectively promoted Suzuki–Miyaura couplings of heteroaryl bromides and chlorides with a range of boronic acids to give the corresponding aryl compounds in high yield. The yield was increased with increasing steric bulkiness of the substituted group. Especially, 1‐(2,6‐diisopropylphenyl)‐3‐N‐(2,4,6‐tri‐tert‐butylphenylacetamido)imidazolium bromide ( 4bc ) exhibited 850,000 TON in the coupling reaction of 2‐bromopyridine and phenylboronic acid. In addition, pharmaceutical compounds such as milrinone and irbesartan were synthesized via Suzuki–Miyaura coupling using sterically bulky, amido‐N‐imidazolium salt ( 4bc ) as a ligand.     

Experimental flame speed in multi-layered nano-energetic materials

This paper deals with the reaction of dense Metastable Intermolecular Composite (MIC) materials, which have a higher density than conventional energetic materials. The reaction of a multilayer thin film of aluminum and copper oxide has been studied by varying the substrate material and thicknesses. The in-plane speed of propagation of the reaction was experimentally determined using a time of- flight technique. The experiment shows that the reaction is completely quenched for a silicon substrate having an intervening silica layer of less than 200 nm. The speed of reaction seems to be constant at 40 m/s for silica layers with a thickness greater than 1 μm. Different substrate materials such as glass and photoresist were also used.     

Homologous recombination of a flanking repeat gene cluster is a mechanism for a common contiguous gene deletion syndrome

Smith-Magenis syndrome (SMS), caused by del(17)p11.2, represents one of the most frequently observed human microdeletion syndromes. We have identified three copies of a low-copy-number repeat (SMS-REPs) located within and flanking the SMS common deletion region and show that SMS-REP represents a repeated gene cluster. We have isolated a corresponding cDNA clone that identifies a novel junction fragment from 29 unrelated SMS patients and a different-sized junction fragment from a patient with dup(17)p11.2. Our results suggest that homologous recombination of a flanking repeat gene cluster is a mechanism for this common microdeletion syndrome.     

Information requirements analysis for holonic manufacturing systems in a virtual environment

The design and development of holonic manufacturing systems requires careful, and sometimes risky, decision making to ensure that they will successfully satisfy the demands of an ever-changing market. In this paper, the authors propose a methodology for a holonic manufacturing systems requirement analysis that is based on a virtual reality approach and aimed at assisting designers of such systems along the entire systems design and development process. Exploiting virtual reality helps the user collect valid information quickly and in a correct form by putting the user and the information support elements in direct relation with the operation of the system in a more realistic environment. A prototype software system tool is designed to realise the features outlined in each phase of the methodology. A virtual manufacturing environment for matching the physical and the information model domains is utilised to delineate the information system requirements of holonic manufacturing systems implementation. A set of rules and a knowledge base is appended to the virtual environment to remove any inconsistency that could arise between the material and the information flows during the requirement analysis.     

Modelling dependable systems using hybrid Bayesian networks

A hybrid Bayesian network (BN) is one that incorporates both discrete and continuous nodes. In our extensive applications of BNs for system dependability assessment, the models are invariably hybrid and the need for efficient and accurate computation is paramount. We apply a new iterative algorithm that efficiently combines dynamic discretisation with robust propagation algorithms on junction tree structures to perform inference in hybrid BNs. We illustrate its use in the field of dependability with two example of reliability estimation. Firstly we estimate the reliability of a simple single system and next we implement a hierarchical Bayesian model. In the hierarchical model we compute the reliability of two unknown subsystems from data collected on historically similar subsystems and then input the result into a reliability block model to compute system level reliability. We conclude that dynamic discretisation can be used as an alternative to analytical or Monte Carlo methods with high precision and can be applied to a wide range of dependability problems.     

Nitrate Capture Investigation in Plasma-Activated Water and Its Antifungal Effect on Cryptococcus pseudolongus Cells

This research investigated the capture of nitrate by magnesium ions in plasma-activated water (PAW) and its antifungal effect on the cell viability of the newly emerged mushroom pathogen Cryptococcus pseudolongus. Optical emission spectra of the plasma jet exhibited several emission bands attributable to plasma-generated reactive oxygen and nitrogen species. The plasma was injected directly into deionized water (DW) with and without an immersed magnesium block. Plasma treatment of DW produced acidic PAW. However, plasma-activated magnesium water (PA-Mg-W) tended to be neutralized due to the reduction in plasma-generated hydrogen ions by electrons released from the zero-valent magnesium. Optical absorption and Raman spectra confirmed that nitrate ions were the dominant reactive species in the PAW and PA-Mg-W. Nitrate had a concentration-dependent antifungal effect on the tested fungal cells. We observed that the free nitrate content could be controlled to be lower in the PA-Mg-W than in the PAW due to the formation of nitrate salts by the magnesium ions. Although both the PAW and PA-Mg-W had antifungal effects on C. pseudolongus, their effectiveness differed, with cell viability higher in the PA-Mg-W than in the PAW. This study demonstrates that the antifungal effect of PAW could be manipulated using nitrate capture. The wide use of plasma therapy for problematic fungus control is challenging because fungi have rigid cell wall structures in different fungal groups.