Influence of different pulsed electric field strengths on the quality of the grapefruit juice

Grapefruit juice was investigated using pulsed electric fields (PEF) with (electric field strengths: 0, 5, 10, 15, 20 and 25 kV cm^?1; flow rate: 80 mL min^?1; pulse frequency: 1 kHz at 40 °C for 600 μs). Total phenolics, DPPH, total antioxidant capacity (TAC), total anthocyanins, total carotenoids, sugars and physicochemical properties of grapefruit juice were studied. In addition, the effect of PEF treatment on micro‐organisms was also observed. Results indicated that no significant change was observed in pH, Brix, titratable acidity, sugars, total anthocyanins and colour attributes with the increase in pulsed electric strength as compared to control treatment. However, significant decrease in nonenzymatic browning (NEB) and viscosity while an increase in cloud value, DPPH, TAC, total phenolics and total carotenoids, while reduction in the activity of micro‐organisms, was also observed with the increase in pulsed electric strength as compared to control treatment. This study suggested that PEF at 25 kV cm^?1 could improve the quality of grapefruit juice.     

Biogenic Amine Formation and Microbiological Quality of Anchovy (Engraulis encrasicolus) Treated with Lavender and Lemon Balm Ethanol Extracts

Biogenic amine formation and bacterial growth of vacuum‐packed European anchovy treated with 1% lemon balm (LB) or lavender (LD) ethanol extracts was investigated. The treated samples were stored at 2 ± 1 °C for 11 d and analyzed for biogenic amines, total viable count, fecal coliform count, and lactic acid bacterial count. The analyses were done on 0, 4, 7, 9, and 11 d of storage. Both LB and LD extracts proved effective in reducing most biogenic amines, with histamine reduced by 3‐fold compared to control. The calculated biogenic amine index showed that LB extract was the most effective in inhibiting the biogenic amine formation. The reduction in total viable count was low and the bacterial contamination reached more than 7 log cfu/g at the end of the storage period for all the samples. Moreover, the reduction in fecal coliform and lactic acid bacterial count by LB and LD extracts was below 1 log cfu/g. Treatment of European anchovy with LB and LD extracts proved to be a very effective preservation technique to reduce the biogenic amine formation and lower the risk of histamine fish poisoning but is not effective in reduction of bacterial load. Consequently, LB and LD extracts could be used to reduce the biogenic amine formation which provides additional safety prior to spoilage for histamine sensitive fish species.     

Yield and P uptake by wheat as affected by residual and applied P

The effect of residual (built up in continued fertilizer experiments) and applied P in Fatehpur loamy sand and Jodhan sandy loam soils of two long term experiments on its availability and uptake by wheat (Triticum aestivum L.) was studied using³²P in greenhouse experiment. Dry matter yield increased significantly with carry over P. Response in the absence of residual P was observed up to a direct application of 134 kg P ha^?1, whereas, in the presence of carry over P, the response was confined upto 67 kg P ha^?1 at site A. The response was however, observed up to 67 kg P ha^?1 irrespective of carry over P at site B. Total P uptake by wheat was significantly increased at all levels of residual P. However, it did not differ signficantly among levels of residual P when these were high. The uptake of soil P (residual) increased signficantly with increase in the dose of directly applied P, indicating that addition of inorganic P fertilizer tends to mobilize the native soil P. Per cent utilization of fertilizer P was enhanced in soils having residual P from continuous application of both inorganic and organic P sources.     

Synthesis,growth and structural perfection of nonlinear optical material of glycine hydrofluoride (GHF)

In the present communication, we have successfully synthesized the efficient NLO material of glycine hydrofluoride (GHF) by conventional chemical reaction, and grown the single crystal by adopting slow evaporation solution growth technique. In order to know its suitability for device fabrication, different characterization analyses have been performed. The lattice constants have been determined from powder X-ray diffraction (PXRD) method and found that it crystallizes in orthorhombic crystal system. Its crystalline perfection was evaluated by high-resolution X-ray diffraction technique (HRXRD) and the value of FWHM indicates the presence of low angle structural grain boundaries. Its luminescence behaviour has been analysed by photoluminescence (PL) analysis and found maximum luminescence in the lower wavelength region. Its relative second harmonic generation efficiency was evaluated from Kurtz powder technique. The phase matching angle of GHF was determined by using Nd:YAG laser as a source. Its thermal, mechanical and electrical properties were examined by TG/DTA, Vickers microhardness tester and dielectric measurements, respectively.     

Performance optimization of silicon-doped titanium dioxide and multiwalled carbon nanotubes tricomposite nanostructures for electrical and optical applications

Journal of Materials Science: Materials in Electronics - Combination nanostructures of metal, semiconductor oxides and carbon materials pursued well in optical and electrical devices. Here we...     

Ab-initio study of the structural,optoelectronic, magnetic,hydrogen storage properties and mechanical behavior of novel combinations of hydride perovskites LiXH3 (X = Cr,Fe, Co, & Zn) for hydrogen storage applications

Journal of Computational Electronics - LiXH3 (X?=?Cr, Fe, Co, & Zn) hydride type perovskites have been studied by applying density functional theory (DFT), and their structural,...     

Body movement activity recognition for ambulatory cardiac monitoring

Wearable electrocardiogram (W-ECG) recorders are increasingly in use by people suffering from cardiac abnormalities who also choose to lead an active lifestyle. The challenge presently is that the ECG signal is influenced by motion artifacts induced by body movement activity (BMA) of the wearer. The usual practice is to develop effective filtering algorithms which will eliminate artifacts. Instead, our goal is to detect the motion artifacts and classify the type of BMA from the ECG signal itself. We have recorded the ECG signals during specified BMAs, e.g., sitting still, walking, movements of arms and climbing stairs, etc. with a single-lead system. The collected ECG signal during BMA is presumed to be an additive mix of signals due to cardiac activities, motion artifacts and sensor noise. A particular class of BMA is characterized by applying eigen decomposition on the corresponding ECG data. The classification accuracies range from 70% to 98% for various class combinations of BMAs depending on their uniqueness based on this technique. The above classification is also useful for analysis of P and T waves in the presence of BMA.     

Method for the direct observation and quantification of survival of bacteria attached to negatively or positively charged surfaces in an aqueous medium

The risk of groundwater contamination by microbial pathogens is linked to their survival in the subsurface. Although there is a large body of literature on the inactivation behavior of suspended (planktonic) microorganisms, little is known about the inactivation of bacteria when attached to sand grain surfaces in groundwater aquifers. The main goal of this study was to develop a fluorescence-based experimental technique for evaluating the extent of inactivation over time of bacteria adhered onto a surface in an aqueous environment. Key features of the developed technique are as follows: (i) attached cells do not need to be removed from the surface of interest for quantification, (ii) bacterial inactivation can be examined in real-time for prolonged time periods, and (iii) the system remains undisturbed (i.e., the aqueous environment is unchanged) during the assay. A negatively or positively charged substrate (i.e., bare or coated glass slide) was mounted in a parallel-plate flow cell, bacteria were allowed to attach onto the substrate, and the loss of bacterial membrane integrity and respiratory activity were investigated as a function of time by fluorescence microscopy using Live/Dead BacLight and BacLight RedoxSensor CTC (5-cyano-2,3-ditolyl tetrazolium chloride) viability assays. These two different measures of bacterial inactivation result in comparable trends in bacterial inactivation, confirming the validity of the experimental technique. The results of this work show that the developed technique is sensitive enough to distinguish between the inactivation kinetics of different representative bacteria attached to either a negatively charged (bare glass) surface or a positively charged (coated glass) surface. Hence, the technique can be used to characterize bacterial inactivation kinetics when attached to environmentally relevant surfaces over a broad range of groundwater chemistries.     

Core-shell morphology and characterization of carbon nanotube nanowires click coupled with polypyrrole

Core-shell nanowires having multiwalled carbon nanotubes (MWNT) as a core and polypyrrole (PPy) as a shell were synthesized using Cu(I)-catalyzed azide-alkyne cycloaddition click chemistry. According to transmission electron microscopy measurements, the uniform PPy layers of 10-20 nm in thickness were formed well on the MWNT's surface. In particular 'grafting from' click coupling was more effective in obtaining uniform and stable core-shell nanowires as well as in the reaction yield, compared to 'grafting to' click coupling. This is due to chemical bond formation between PPy and MWNT in equal intervals along the longitudinal direction of the MWNT, achieved by 'grafting from' click coupling. As a result, the core-shell nanowires were very stable even in the sonication of nanowires and showed an enhanced electrical conductivity of 80 S cm(-1), due to the synergetic interaction between MWNTs and PPy, which is higher than the conductivity of pure MWNTs and pure PPy. In addition, the core-shell nanowires could show better NO2 gas sensing properties compared to pure MWNTs and pure PPy as well as MWNT/PPy composites prepared by in situ polymerization. The synthesized core-shell nanowires would play an important role in preparing electrical and sensing devices.     

Macroporous open cell polyester amphigel using citric acid and PEO: Solvent absorption,thermal behavior,and slow release of pesticide

This article describes citric acid cross-linked amphiphilic poly(ethylene oxide) (PEO) macroporous open cell polyester amphigel, optimally synthesized using response surface methodology by applying central composite design to screen significant reaction parameters for maximizing percent water sorption. The chemical structure of the amphigel was confirmed by proton nuclear magnetic resonance (¹H NMR), FT-IR and the thermal behavior was studied using thermo-gravimetric and DSC. Due to amphiphilic nature, the amphigels also showed high chloroform (1151.33%–1193.33%) and water (755.33%–865%) absorption capacity. Thermal analysis revealed that amphigels are less thermal stability as compared to PEO, however, the degradation process was found to be multi step. The amphigel was effectively used as a carrier for easy loading of a hydrophobic pesticide and showed a slow release of the same.