Evaluation of high Ni-Cr-Mo alloys for the construction of sulfur dioxide scrubber plants

Corrosion in wet lime/limestone systems used for flue gas desulfurization in thermal power plants is of great concern. The frequent variations in acidity and in chloride and fluoride ion concentrations experienced by such systems pose a serious threat to the materials of construction. Currently used materials mostly type 316L stainless steel often fail to meet their life expectancy. The present study evaluates the performance of advanced Ni- Cr- Mo alloys 59 and C- 276 in a simulated sulfur dioxide scrubber environment. Accelerated tests showed that high Ni- Cr- Mo alloys have little tendency to leach metal ions such as chromium, nickel, and molybdenum at different impressed potentials. Scanning electron microscopy was used to examine the morphology of pitting attack.     

Performance of floating cum tilted-wick type solar still with the effect of water flowing over the glass cover

A simple transient performance of floating cum tilted-wick type solar still has been presented by incorporating the effects of water flowing over a glass cover, heat capacity of tilted-wick water surface and floating-wick water surface. Explicit expressions for flowing water, glass, tilted-wick water surface and floating-wick water surface temperature and efficiency of the system have been derived. Numerical calculations have been carried out for a typical day in the month of March 2004. The relative standard deviations between the numerical and experimental results of different temperature components of the proposed still have been found. The results indicate that the relative standard deviations between theoretical and experimental results are less than 8% (glass cover), 2% (tiltedwick water surface), 1% (floating-wick water surface) and 2% (flowing water at the lower end of the glass cover) an average for the working hours of the day. Moreover, based on the numerical results, the following conclusions have been drawn: (i) glass cover temperature decreases significantly; (ii) the effect of water flowing over the glass cover has a fascinating effect on the production of distillate output during peak sunny hours; (iii) water flow rate of 1.5 m/s is optimum, and beyond it the efficiency decreases. Experimental investigations have been performed at Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore, India.     

Hybrid Metaheuristics Web Service Composition Model for QoS Aware Services

Recent advancements in cloud computing (CC) technologies signified that several distinct web services are presently developed and exist at the cloud data centre. Currently, web service composition gains maximum attention among researchers due to its significance in real-time applications. Quality of Service (QoS) aware service composition concerned regarding the election of candidate services with the maximization of the whole QoS. But these models have failed to handle the uncertainties of QoS. The resulting QoS of composite service identified by the clients become unstable and subject to risks of failing composition by end-users. On the other hand, trip planning is an essential technique in supporting digital map services. It aims to determine a set of location based services (LBS) which cover all client intended activities quantified in the query. But the available web service composition solutions do not consider the complicated spatio-temporal features. For resolving this issue, this study develops a new hybridization of the firefly optimization algorithm with fuzzy logic based web service composition model (F3L-WSCM) in a cloud environment for location awareness. The presented F3L-WSCM model involves a discovery module which enables the client to provide a query related to trip planning such as flight booking, hotels, car rentals, etc. At the next stage, the firefly algorithm is applied to generate composition plans to minimize the number of composition plans. Followed by, the fuzzy subtractive clustering (FSC) will select the best composition plan from the available composite plans. Besides, the presented F3L-WSCM model involves four input QoS parameters namely service cost, service availability, service response time, and user rating. An extensive experimental analysis takes place on CloudSim tool and exhibit the superior performance of the presented F3L-WSCM model in terms of accuracy, execution time, and efficiency.     

Evaporative heat loss and heat transfer for open- and closed-cycle systems of a floating tilted wick solar still

An analytical expression for the thermal efficiency of evaporative heat loss and heat transfer for a open- and closed-cycle systems of floating tilted wick solar stills in terms of system design and climatic parameters has been derived. The expression for open- and closed-cycle systems was validated by performing experiments for both systems. Optimization of the design of the still for evaporative cooling (open cycle) and the distillation unit (closed cycle) was obtained using the derived analytical expression for large-scale installation. Numerical calculations were also carried out for a typical summer day at the Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore, India, to predict the performance of the still.     

Carboxymethyl sago pulp/chitosan hydrogel as an immobilization medium for activated sludge for p-nitrophenol biodegradation

In this study, carboxymethyl sago pulp (CMSP) derived from sago waste was successfully crosslinked with ferric ions in the presence of chitosan forming a novel immobilization matrix for p-nitrophenol (PNP)-acclimated activated sludge. On the basis of the shortest biodegradation time of PNP, the optimized operational conditions of immobilization were found to be: 7 w/v% CMSP, 9 g L⁻¹ of activated sludge, 0.1 M ferric ion, and 15 min of crosslinking time. Observable inhibited PNP biodegradation was exhibited by the suspended activated sludge at the initial PNP concentration of 400 mg L⁻¹. In contrast, complete mineralization was achieved by the CMSP/chitosan-immobilized activated sludge (CMSP/Ch-AS) beads. The results revealed the important role of CMSP/Ch hydrogel in protecting activated sludge from the toxicity of PNP. The CMSP/Ch-AS beads could be reused consecutively up to three and two cycles, respectively, for the biodegradation of PNP at 200 and 400 mg L⁻¹, with the attainment of more than 99% of PNP removal at each cycle. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47531.     

Polyhydroxy propionate-co-hydroxy dodecanoate-co-hydroxy octadecanoate for in vitro cell culture

This study is novel to report the utilization of molasses for the production of polyhydroxy propionate-co-hydroxy dodecanoate-co-hydroxy octadecanoate from Pseudomonas sp. LDC-5 as prospective biomaterial. Thermal analysis revealed its potential for thermal permanence and melt processing. 3T3 fibroblasts were cultured on these different scaffolds and their proliferation was compared. Giemsa and acridine orange/ethidium bromide staining revealed that there was no distinct change in morphology. Polyhydroxyalkanoate:poly ethylene glycol blend was found to be the most promising for extracellular matrix secretion, a key thrust function of 3D culture. Lactate dehydrogenase assay indicated the membrane integrity. DNA fragmentation analysis showed that the scaffold did not damage DNA. Thus the prepared scaffold can serve as a promising biomaterial.     

Experimental Result on Heat Transfer during Quenching of Hot Steel Plate by Spray Impingement

The present article discusses the experimental results on cooling characteristics of a stationary hot steel plate by spray impingement. The experimental setup consisted of an electrically heated flat stationary steel plate of dimension 120 mm × 120 mm × 4 mm, spray setup, water supply, and air supply unit. The effects of various controlling parameters such as air-water pressures, water flow rate, nozzle tip to target distance and impingement density were determined and analyzed. The cooling rates were computed from the time-dependent temperature history and used to analyze the parametric effects. The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods available in the open literature.     

Dual crosslinked carboxymethyl sago pulp/pectin hydrogel beads as potential carrier for colon‐targeted drug delivery

Carboxymethyl sago pulp (CMSP)/pectin hydrogel beads were synthesized by calcium crosslinking and further crosslinked by electron beam irradiation to form drug carrier for colon‐targeted drug. Sphere‐shaped CMSP/pectin 15%/5% hydrogel beads is able to stay intact for 24 h in swelling medium at pH 7.4. It shows pH‐sensitive behavior as the swelling degree increases as pH increases. Fourier transform infrared spectroscopy analysis confirmed the absence of chemical interaction between hydrogel beads and diclofenac sodium. Differential scanning calorimetric and X‐ray diffraction studies indicate the amorphous nature of entrapped diclofenac sodium. The drug encapsulation efficiency is up to about 50%. Less than 9% of drug has been released at pH 1.2 and the hydrogel beads sustain the drug release at pH 7.4 over 30 h. This shows the potential of CMSP/pectin hydrogel beads as carrier for colon‐targeted drug. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43416.     

Synthesis and characterization of ferroelectric side chain liquid crystal polymers bearing banana-shaped chiral mesogens

A series of ferroelectric liquid crystal polymers having banana-shaped side chain mesogens were synthesized through photo-polymerization of epoxide moiety. 2,5-disubstituted-thiophene sub-unit was used in synthesizing the banana-shaped monomers. These liquid crystal compounds were characterized by NMR, differential scanning calorimetry (DSC) and optical polarized microscopy (POM). Mesomorphism was investigated as a function of spacer units. All the synthesized low molar mass banana-shaped compounds exhibit smectic blue phase, but chiral smectic C phase could be observed only on compounds having longer spacer. The clearing temperature of low molar mass compounds fluctuated a little when spacer length varies. All polymers exhibit cholesteric mesophase and an observable glass transition. These liquid crystalline compounds reveal strong photoluminescence at visible region (λ_max = 475 nm for M9EPX) and have potential use in polarized organic light emitting diode materials.