Experimental validation of PID based cascade control system through SCADA–PLC–OPC and internet architectures

The paper presents the experimental validation procedure of a simple cascade control system through number of architectures, such as SCADA, PLC, OPC and internet. The performance and effectiveness of individual architecture is evaluated on the basis of data rate, rise time, peak time and settling time. In this study, PID is implemented on Micrologix-1200 PLC and RSView-32 SCADA has been used with RSLinx communication software. The PLC–SCADA control loop is implemented with the functionalities such as, real time data analysis, set point modifications, automatic report generation and integration of data with MS-Excel and MS-Access. The enhancement in project data analysis is effectively done through the integration of PLC with Labview. The remote monitoring and control of process parameters is done using NET-ENI. The obtained result proved that the conventional SCADA based control system can be enhanced further more with PLC as well as NI-OPC server significantly.     

Investigation on sulphonated PEEK beads for drug delivery,bioactivity and tissue engineering applications

Poly ether ether ketone (PEEK) has wide applications in the field of medicine as a prosthetic material and can be sulphonated using sulphuric acid. This study focuses on the fabrication of water soluble SPEEK beads using infusion pump and the obtained beads were characterised using Fourier Transform Infra Red (FTIR) spectroscopy to confirm the sulphonation, while their surface morphology was studied using scanning electron microscope (SEM). In order to study the bioactivity of the prepared beads, hydroxyapatite was dispersed within them followed by their immersion in SBF. In order to study the drug release kinetics of the beads, they were loaded with amoxicillin in different concentrations. Cytotoxicity studies were performed by MTT method and ALP activity was measured using mouse osteoblast cells (MC3T3-E1). The SEM and FTIR of the prepared beads confirmed the morphology and the sulphonation of the prepared beads. Also, the apatite formation on the SPEEK beads, subsequent to their immersion in SBF, proved that the beads possessed excellent bioactivity. Moreover, the beads developed exhibited low cytotoxicity, implying good biocompatibility and safety. Thus, the results of the study indicated that the novel SPEEK beads could potentially be used as a drug carrying vehicle with low toxicity.     

Fabrication and characterization of polymethylmethacrylate/polysulphone/β-tricalcium phosphate composite for orthopaedic applications

Polymethylmethacrylate (PMMA) and polysulphone (PSu) are biocompatible polymers and are used widely for biomedical applications. In this study, a blend membrane of PMMA/PSu was fabricated using methylene bisacrylamide (MBA) as the blending agent and its properties were studied. Subsequently, a composite membrane consisting of β-tricalcium phosphate (β-TCP) filler dispersed in a polymer matrix of PMMA/PSu was fabricated and evaluated for application as an orthopaedic prosthetic material. Fourier Transform Infrared Spectroscopy spectra of the blend confirmed the interaction of PMMA and PSu with the blending agent MBA. The X-ray diffraction analysis showed that PMMA/PSu membranes exhibited a higher degree of crystallinity when compared with that of the individual polymers. The thermal properties of the samples studied by thermogravimetric analysis showed an increase in the thermal stability of the PMMA/PSu when compared with individual PMMA and PSu membranes. The morphology of the composite samples analysed through SEM showed that the fillers were widely distributed and agglomerated at certain places. The tensile strength of the PMMA/PSu/β-TCP was found to be inferior to that of PMMA/β-TCP although much superior to that of PSu/β-TCP composite membranes. Hardness testing performed using durometer hardness tester (Shore D) showed that the PMMA/PSu/β-TCP samples exhibited higher hardness than the composites having individual PMMA and PSu matrices. Analysis of the optical properties of the polymer membranes suggested good blend formation between PMMA and PSu. The in vitro bioactivity study suggested that the density of the calcium phosphate layer formed on the surface of PMMA/PSu/β-TCP was much higher than that of composites made of either PMMA or PSu matrix. The results of the study showed that the blended composite membranes exhibited favourable properties for biomedical applications such as for orthopaedic prostheses.     

Alterations in antioxidant enzyme activities and oxidative damage in alcoholic rat tissues: Protective role of Thespesia populnea

Recent advances in our understanding of the pathogenesis of alcohol-induced hepato-renal injury and the development of new approaches to its treatment have been reported in various works. This study involves alcohol-induced oxidative stress linked to the metabolism of ethanol involving both mitochondrial and peroxisomal fractions of liver and kidney. Alcohol treatment resulted in the depletion of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), Glutathione-S-Transferase (GST) activities, and reduced glutathione (GSH) content, higher level of malondialdehyde (MDA) and lower levels of protein carbonyls (PC) causing malfunction of hepatic and renal tissues, when compared to control rats. Thespesia populnea (TP) leaf extracts, administered to chronic alcohol ingested rats, were envisaged to possess significant antioxidant defence properties and help in the recovery of tissues from alcohol-induced oxidative damage. The results showed that degenerative changes in hepatic and renal cells of alcoholic groups were minimized by the administration of TP leaf extracts as also revealed by histopathological examination. The current findings indicate that treatment with TP extracts reduces alcohol-induced oxidative stress, thereby protecting the hepatic and renal tissue from alcohol-induced damage.     

Synthesis,characterization of novel silicotungstic acid incorporated SPEEK/PVA-co-ethylene-based composite membranes for fuel cell

Sulfonated polyether ether ketone (SPEEK) is prepared by the sulfonation of polyether ether ketone (PEEK). Five of the composite membranes (PSW1–PSW5) with various percentage compositions of the SPEEK, PVA-co-ethylene, and silicotungstic acid (SWA) were prepared. The prepared composite membranes were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Surface morphology of the composite membranes was analyzed using scanning electron microscopy (SEM). Other evaluations related to conductivities (ion exchange capacity, IEC), proton conductivity), absorptivity (water and methanol absorption), durability and mechanical properties (tensile strength and percentage elongation) were also evaluated for the composite membranes. Among the five composite membranes, composite membrane with higher SWA content, PSW5 (which has 10% SWA) showed more conductivity compared to other membranes. These composites also showed very good conductivities, mechanical properties, and durabilities. Hence, these composite membranes have the potential to be used in the development of newer proton exchange membrane fuel cells (PEMFCs).     

Detection of quadratic phase coupling from human EEG signals using higher order statistics and spectra

Interactions among neural signals in different frequency components have become a focus of strong interest in biomedical signal processing. The bispectrum is a method to detect the presence of quadratic phase coupling (QPC) between different frequency bands in a signal. The traditional way to quantify phase coupling is by means of the bicoherence index (BCI), which is essentially a normalized bispectrum. The main disadvantage of the BCI is that the determination of significant QPC becomes compromised with noise. To mitigate this problem, a statistical approach that combines the bispectrum with an improved surrogate data method to determine the statistical significance of the phase coupling is introduced. The method was first tested on two simulation examples. It was then applied to the human EEG signal that has been recorded from the scalp using international 10–20 electrodes system. The frequency domain method, based on normalized spectrum and bispectrum, describes frequency interactions associated with nonlinearities occurring in the observed EEG.     

Electrochemical treatment of reactive dye effluent using solar energy

The electrochemical degradation of a commonly used textile dye, Reactive Green HE4BD, employing solar energy has been investigated. The influence of parameters such as electrolyte concentration, current density, pH and initial dye concentration were studied. Under optimal conditions, 99% decoloration and a significant reduction in chemical oxygen demand were observed after 5 h treatment. Evaluation of the process showed that degradation of the dye followed pseudo first-order kinetics.     

Rapid Room‐Temperature Synthesis of Metal–Organic Framework HKUST‐1 Crystals in Bulk and as Oriented and Patterned Thin Films

Whereas the preparation of defined metal–organic framework (MOF) materials via hydrothermal or diffusion methods typically requires hours to days, our simple precipitation route opens the access to the well‐known HKUST‐1 frameworks within minutes. Crucial for the formation of a well‐defined, crystalline material is the choice of suitable precipitating solvents, with methanol and ethanol being the most favorable ones. This approach could be extended to the formation of dense, surface‐mounted MOF films (so‐called SURMOFs), in particular if the surfaces are decorated with suitable binding groups by formation of self‐assembled monolayers (SAMs). By combination with micro‐contact printing (μCP), patterned SURMOFs became accessible, in which the precipitating solvent is decisive on the formation of either spatially restricted films or single particles.     

Effect of Dissolved Oxygen on Oxic/Anoxic Diauxic Lag of P.?denitrificans

Nitrogen is removed in suspended growth wastewater treatment systems by passing mixed liquor from an aerobic zone in which nitrification takes place to an anoxic zone in which denitrification takes place. Following the switch from oxygen to nitrate as terminal electron acceptor, a diauxic lag may occur. The present study tested the hypothesis that lower dissolved oxygen concentrations in the aerobic phase lead to shorter diauxic lags. Bacterial cultures exposed to low dissolved oxygen concentrations (<0.70 mg/L) during the aerobic growth phase had significantly shorter diauxic lags than cultures grown at air saturation. Furthermore, these cultures generally grew faster during the anoxic phase. These results indicate that the effect of dissolved oxygen concentration in aerobic reactors on diauxic lags and anoxic growth rates in anoxic reactors should be considered in the design and operation of nitrogen-removing, suspended growth biological treatment processes.