Antifungal activity and chemical composition of Citrus reticulata Blanco essential oil against phytopathogens from North East India

The essential oil (EO) isolated by hydro-distillation from the peel of fully matured ripen fruits of Citrus reticulata Blanco were analyzed by GC and GC-MS. Thirty seven different components were identified constituting approximately ≥99% of the oil. The major components were limonene (46.7%), geranial (19.0%), neral (14.5%), geranyl acetate (3.9%), geraniol (3.5%), β-caryophyllene (2.6%), nerol (2.3%), neryl acetate (1.1%) etc. The antifungal activity of the oil was tested by poisoned food (PF) technique and the volatile activity (VA) assay against five plant pathogenic fungi viz Alternaria alternata (Aa), Rhizoctonia solani (Rs), Curvularia lunata (Cl), Fusarium oxysporum (Fo) and Helminthosporium oryzae (Ho). The oil showed better activity in VA assay. The Minimum inhibitory concentration (MIC) for Aa, Rs and Cl was 0.2 ml/100 ml whereas >0.2 ml/100 ml for Fo and Ho in PF technique. Fungal sporulation was also completely inhibited at 2 ml/100 ml of the oil except for Cl and Ho, which was only 0.5% (±0.5) and 0.25% (±0.25) respectively as compared to control.     

Electrical transport and morphological studies of polyaniline nanostructures

Polyaniline nanostructures have been synthesized by self‐assembly method by varying the dopant to monomer molar ratio. High resolution transmission electron micrographs show how the dopant to monomer molar ratio influences on the morphology and structure. The temperature dependence of dc conductivity study shows semiconducting behavior. From dc conductivity study it has been observed that conductivity increases with increasing dopant concentration and maximum conductivity is attained at dopant to monomer molar ratio of 3:4. From the slope of the reduced activation energy versus temperature plot it is confirmed that the charge transport in polyaniline nanostructures is in insulating regime and dominated by variable range hopping mechanism. In particular, a crossover from 1D to 3D variable range hopping conduction is observed by changing the dopant to monomer molar ratio. With increasing the dopant concentration the 680 nm absorption peak shifted towards higher wavelength range. The red shifting of this peak indicates the increased extent of π‐conjugation length. The enhancement of characteristic band intensity at 1336 cm^?1 in Micro‐Raman spectra indicates the increase of delocalization degree. Temperature profiles of the degradation processes have been mapped using thermogravimetry analyzer and it is observed three‐step weight losses for all the samples. POLYM. ENG. SCI., 55:995–1002, 2015. © 2014 Society of Plastics Engineers     

Microalgae Chlorella as a potential bio-energy feedstock

Microalgae are promising biomass species owing to their fast growth rate and high CO₂ fixation ability as compared to terrestrial plants. Microalgae have long been recognized as potentially good source for biofuel production because of their high oil content and rapid biomass production. In this study Chlorella sp. MP-1 biomass was examined for its physical and chemical characteristics using Bomb calorimeter, TGDTA, CHN and FTIR. The proximate composition was calculated using standard ASTM methodology. Chlorella sp. MP-1 biomass shows low ash (5.93%), whereas high energy (18.59 MJ/kg), carbohydrate (19.46%), and lipid (28.82%) content. The algal de-oiled cake was characterized by FTIR spectroscopy and thermogravimetric study at 10 °C/min and 30 °C/min to investigate its feasibility for thermo-chemical conversion. The present investigation suggests that within the realm of biomass energy technologies the algal biomass can be used as feedstock for bio and thermo-chemical whereas the de-oiled cake for thermo-chemical conversion thereby serving the demand of second generation biofuels.     

Space-charge-limited currents in polymethylmethacrylate films

An investigation was undertaken to examine the conduction mechanism in polymethylmethacrylate (PMMA) films. The current was measured in Al/PMMA/Al capacitors in the voltage range 4–300 V.     

Ranking of single-valued neutrosophic numbers through the index of optimism and its reasonable properties

Artificial Intelligence Review - In this paper an innovative method of ranking neutrosophic number based on the notions of value and ambiguity of a single-valued neutrosophic number is being...     

Effect of impinging ion energy on the substrates during deposition of SiOx films by radiofrequency plasma enhanced chemical vapor deposition process

Radiofrequency (13.56 MHz) plasma enhanced chemical vapor deposition process is used for deposition of SiO_x films on bell metal substrates using Ar/hexamethyldisiloxane/O₂ glow discharge. The DC self-bias voltage developed on the substrates is observed to be varied from − 35 V to − 115 V depending on the RF power applied to the plasma. Plasma potential measurements during film deposition process are carried out by self-compensated emissive probe. The deposited films are characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nanoindentation, nano-scratch test and thermogravimetric analysis. The characterization results show strong dependency of the SiO_x films properties on the energy of the ions impinging on the substrates during deposition. Analysis of Raman spectra indicates an increase in vitreous silica content and reduction in defective Si-O-Si chemical structure in the deposited SiO_x films with increasing ion energy impinging on the substrates. The increase in inorganic (Si and O) content in the SiO_x films is further confirmed from XPS analysis. The growth of SiO_x films with more inorganic content and defect free chemical structure apparently contribute to the increase in their hardness and scratch resistance behavior. The films show higher thermal stability as the energy of the ions arriving at substrates increases with DC self-bias voltage. The possibility of using SiO_x films for surface protection of bell metal is also explored.     

Effect of Essential Oils from <Emphasis Type="Italic">Lippia geminata</Emphasis> and <Emphasis Type="Italic">Cymbopogon jwarancusa</Emphasis> on In vitro Growth and Sporulation of Two Rice Pathogens

Sheath blight and brown spot disease of rice caused by Rhizoctonia solani and Bipolaris oryzae causes significant yield loss in rice production worldwide. The present study was undertaken to examine the effect of two essential oils (EOs) from Lippia geminata and Cymbopogon jwarancusa on in vitro growth and sporulation of these two pathogens. The fungal radial growth was inhibited at very low concentration (25 ppm) of the EOs. Similarly, fungal spore production was also inhibited up to ≥80% at 500 ppm of EOs. However, fungal sporulation was completely retarded at 1,000 ppm of L. geminata EO. Very low oil concentrations (10 ppm) accelerated the radial growth (0–5 mm) and spore germination (3.5–8.5%) of the pathogens. At higher oil concentrations, the mycelial growth and spore productions were completely inhibited. The IC₅₀ value of the EO of C. jwarancusa was 365.45 and 336.74 ppm and for L. geminata, it was 420.16 and 481.47 ppm against B. oryzae and R. solani, respectively. GC–MS analysis of the oils showed 54.36% piperitone and 30.86% α-phellandrene as major compounds in C. jwarancusa whereas 25.9% geranial and 14.6% neral in L. geminata oil. Essential oils from Lippia geminata and Cymbopogon jwarancusa appear to be good candidates for the in vitro control of these two rice pathogens and can be successfully utilized in management strategies of pathogens in appropriate formulation.     

Adsorption of As(V) on surfactant-modified natural zeolites

Natural mordenite (NM), natural clinoptilolite (NC), HDTMA-modified natural mordenite (SMNM) and HDTMA-modified natural clinoptilolite (SMNC) have been proposed for the removal of As(V) from aqueous solution (HDTMA=hexadecyltrimethylammonium bromide). Influence of time on arsenic sorption efficiency of different sorbents reveals that NM, NC, SMNM and SMNC require about 20, 10, 110 and 20h, respectively to reach at state of equilibrium. Pseudo-first-order model was applied to evaluate the As(V) sorption kinetics on SMNM and SMNC within the reaction time of 0.5h. The pseudo-first-order rate constants, k are 1.06 and 0.52h(-1) for 1 and 0.5g of SMNM, respectively. The observed k values 1.28 and 0.70h(-1) for 1 and 0.5g of SMNC, respectively are slightly high compared to SMNM. Surfactant surface coverage plays an important role and a significant increase in arsenate sorption capacity could be achieved as the HDTMA loading level on zeolite exceeds monolayer coverage. At a surfactant partial bilayer coverage, As(V) sorption capacity of 97.33 and 45.33mmolkg(-1) derived from Langmuir isotherm for SMNM and SMNC, respectively are significantly high compared to 17.33 and 9.33mmolkg(-1) corresponding to NM and NC. The As(V) uptake was also quantitatively evaluated using the Freundlich and Dubinin-Kaganer-Radushkevich (DKR) isotherm models. Both SMNM and SMNC removed arsenic effectively over the initial pH range 6-10. Desorption performance of SMNM and SMNC were 66.41% and 70.04%, respectively on 0.1M NaOH regeneration solution.     

Two-phase fluid motion through porous medium with volume fraction: An application of MATLAB bvp4c solver technique

In this paper, we have attempted to study the steady two-dimensional hydromagnetic convective flow through porous medium and heat transfer effects. Fluid is containing dust particles and is moving under the influence of Lorentz, buoyancy, Darcy, and viscous forces. Motion is considered to be governed by the volume fraction of the dust grains and the increment of shear stress and rate of heat transfer at the surface has been analyzed. Governing equations of the problem are converted into ordinary differential equations utilizing similarity transformations. The converted differential equations are figured numerically using the MATLAB built-in technique bvp4c. The results are depicted in graphical forms for different values of the flow parameters. The findings are obtained considering the volume fraction and compared with the results of the previous paper. It is observed that the shear stress enhances with diminishing resistance and decreases for the higher values of the Hartmann number, permeability parameter, and volume fraction of the dust phase. Also, improving the Nusselt number gives a boost to thermal diffusivity.