Electrochemical capacitance of nanostructured ruthenium-doped tin oxide Sn<Subscript>1–<Emphasis Type="Italic">x</Emphasis></Subscript>Ru<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>2</Subscript> by the microemulsion method

Synthesis of nanostructured Ru-doped SnO₂ was successfully carried out using the reverse microemulsion method. The phase purity and the crystallite size were analyzed by XRD. The surface morphology and the microstructure of synthesized nanoparticles were analyzed by SEM and TEM. The vibration mode of nanoparticles was investigated using FTIR and Raman studies. The electrochemical behavior of the Ru-doped SnO₂ electrode was evaluated in a 0.1 mol/L Na₂SO₄ solution using cyclic voltammetry. The 5% Ru-doped SnO₂ electrode exhibited a high specific capacitance of 535.6 F/g at a scan rate 20 mV/s, possessing good conductivity as well as the electrocycling stability. The Ru-doped SnO₂ composite shows excellent electrochemical properties, suggesting that this composite is a promising material for supercapacitors.     

Effect of ecofriendly sealing coat against corrosion protection of steel rebars in concrete

Phosphating is one of the most important chemical conversion treatments for steel, mainly to improve corrosion resistance and paint adhesion and as an absorbing layer for waxes, oils, lacquers, etc. However, phosphate coating are crystalline and porous and need a sealing treatment after phosphating. Chromate sealing is a well known practice, and due to its toxicity, development of an ecofriendly sealing treatment is very essential. This paper focuses on the effect of zinc phosphate chemical conversion coating with the addition of nano-SiO₂ to protect the mild steel rebars against corrosion in chloride contaminated concrete. The coated surfaces were characterised by scanning electron microscopy and X-ray diffraction. Corrosion resistances of coated and uncoated rebars were evaluated by anodic polarisation, linear polarisation resistance, Tafel and alternating current impedance spectroscopy and cyclic polarisation technique. The results indicated that the coated rebars have considerably reduced the corrosion rate even in the presence of 3% chloride environments.     

Analysis of corrosion resistance behavior of inhibitors in concrete using electrochemical techniques

Reinforced concrete is one of the most durable and cost effective construction materials. However, in high chloride environments, it can suffer from corrosion due to chloride induced breakdown of the normal passive layer protecting the reinforcing steel bars inside concrete. One means of protecting embedded steel reinforcement from chloride induced corrosion is the addition of corrosion inhibiting admixtures. In the present investigation, various inhibitors such as sodium nitrite, zinc oxide, mono ethanol amine, diethanolamine, and triethanol amine have been used in concrete in different percentages. Their effectiveness was then studied using various electrochemical techniques such as rapid chloride ion penetration test, open circuit potential measurement, electrochemical impedance measurement, potentiodynamic polarization measurement, and gravimetric weight loss measurement. The results thus obtained indicate that the addition of inhibitors enhances the corrosion resistance properties.     

Chitosan modified with a polydentate crosslinker for metal‐ion adsorption

Extensive study of solution properties of sodium hyaluronate including about 140 samples and covering broad molar mass range was carried out by classical viscometry using an Ubbelohde capillary viscometer and by combination of size‐exclusion chromatography with a multi‐angle light scattering detector and an on‐line viscometer. The study also involved critical overview of literature data of Mark‐Houwink relation for sodium hyaluronate. Continuous decrease of the Mark‐Houwink exponent with increasing molar mass to the values markedly lower than those typical of linear random coils in thermodynamically good solvents was observed. This fact was attributed to branched molecular structure of hyaluronic acid as a result of unknown side reactions during the manufacturing process. The molar mass dependence of the second virial coefficient was determined and proved aqueous salt solutions to be thermodynamically good solvents for sodium hyaluronate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Evaluation of embeddable potential sensor for corrosion monitoring in concrete structures

Embeddable potential sensor based on MnO₂ was assembled and characterised in concrete. The stability, reversibility, polarisability and impedance characteristics have been studied with respect to known reference. The corrosion performance of reinforced steel with respect to MnO₂ sensor was monitored by different electrochemical techniques. Reversibility of MnO₂ sensor indicated that difference of ±5 mV between the forward and reverse scan indicates the better reversibility characteristics in concrete. The rebar potentials (E_R) of steel with respect to MnO₂ are −315 and −525 mV for passive and active conditions of rebar in concrete. The corrosion current from potentiodynamic polarisation and R_ct from a.c. impedance technique clearly differentiated the behaviour of steel embedded in chloride contaminated concrete (active condition) from uncontaminated concrete (passive condition) with respect to MnO₂ sensor. All these studies revealed that corrosion monitoring of steel in concrete using embedded MnO₂ as a better potential sensor for steel in concrete. In addition it is easy to fabricate for amenable miniaturisation, varied configuration as demanded for corrosion monitoring in concrete structures.     

A novel bio-inorganic bone implant containing deglued bone, chitosan and gelatin

With the aim of developing an ideal bone graft, a new bone grafting material was developed using deglued bone, chitosan and gelatin. Deglued bone (DGB) which is a by-product of bone glue industries and has the close crystallographic similarities of hydroxyapatite was used as main component in the preparation of bone implant. Chitosan was prepared from the exoskeleton of prawn (Pinaeus indicus, family Crustaceae) which is a by-product of seafood industries. Chitosan gives toughness to the product and do not allow the DGB particles to wither away when the implant is placed in the defect. Gelatin was used as binder for the preparation of DGB-chitosan composite. The DGB, chitosan and DGB-chitosan-gelatin composite, which were prepared in the laboratory, were analysed for their physicochemical properties by infrared spectroscopy, X-ray diffraction and scanning electron microscopy studies.     

THE CLOSTRIDIUM THERMOCELLUM-CLOSTRIDIUM THERMOSACCHAROLYTICUM ETHANOL PRODUCTION PROCESS: NUTRITIONAL STUDIES AND SCALE-DOWN

The Clostridium thermocellum-Clostridium thermosaccharolyticum mixed culture system has been scaled down into flasks in defined medium MJ with Solka Floe as carbon source. The best saccharolytic culture for use with the cellulolytic, anaerobic thermophile C. thermocellum ATCC 27405 was found to be C. thermosaccharolyticum HG-8 when compared to Clostridium thermo-hydrosulfuricum strain 39E or Thermoanaerobacter ethanolicus ATCC 31937. The defined medium was optimized for a high cellulose concentration by increasing the level of FeSO₄ and by replacing 3-[N-morpholino] propane sulfonic acid (MOPS) buffer by sodium bicarbonate.     

Internet of Things Big Data Security in Cloud via Stream Cipher and Clustering Model

Wireless Personal Communications - Big Data in IoT and Cloud Computing are two important developments over the years, enabling companies to provide efficient and effective IT services. To ensure...     

Enhancement of Sentiment Analysis Using Clause and Discourse Connectives

The sentiment of a text depends on the clausal structure of the sentence and the connectives’ discourse arguments. In this work, the clause boundary, discourse argument, and syntactic and semantic information of the sentence are used to assign the text’s sentiment. The clause boundaries identify the span of the text, and the discourse connectives identify the arguments. Since the lexicon-based analysis of traditional sentiment analysis gives the wrong sentiment of the sentence, a deeper-level semantic analysis is required for the correct analysis of sentiments. Hence, in this study, explicit connectives in Malayalam are considered to identify the discourse arguments. A supervised method, conditional random fields, is used to identify the clause boundary and discourse arguments. For the study, 1,000 sentiment sentences from Malayalam documents were analyzed. Experimental results show that the discourse structure integration considerably improves sentiment analysis performance from the baseline system.