DiGVis: A system for comprehension and creation of directed graphs for the visually challenged

One of the major barriers for the social inclusion of blind persons is the limited access to graphics-based learning resources which are highly vision oriented. This paper presents a cost-effective tool which facilitates comprehension and creation of virtual directed graphs, such as flowcharts, using alternate modalities of audio and touch. It provides a physically accessible virtual spatial workspace and multimodal interface to non-visually represent directed graphs in interactive manner. The concept of spatial query is used to aid exploration and mental visualization through audio and tactile feedback. A unique aspect of the tool, named DiGVis, offers compatible representations of directed graphs for the sighted and non-sighted persons. A study with 28 visually challenged subjects indicates that the tool facilitates comprehension of layout and directional connectivity of elements in a virtual diagram. Further, in a pilot study, blind persons could independently comprehend a virtual flowchart layout and its logical steps. They were also able to create the flowchart data without sighted assistance using DiGVis. A comparison with sighted subjects using DiGVis for similar task demonstrates the effectiveness of the technique for inclusive education.     

An automated enzymic assay for determining the cyanide content of cassava (Manihot esculenta crantz) and cassava products

An automated enzymic method for the analysis of cyanide in cassava and cassava products is described. A total of 300 analyses a day can be handled easily. A wide range of free (nonglycosidic) or bound (cyano-substituted glycosides) cyanides (0.4–40 μg HCN ml^?1) can be assayed in the extracted solutions. The upper limit of detection for the bound cyanide can easily be increased by another three-fold by assaying it under partial hydrolysis conditions. The two enzymic methods, manual and automated on Technicon's AutoAnalyzer, agreed well for the free and the bound cyanide in the leaf and the peeled storage root samples.     

Aggregation and Adsorption Behavior of Cationic Surfactants (Cetyltrimethylammonium Bromide and Dodecyltrimethylammonium Bromide) in Aqueous Solutions of Antibiotic Drug (Amikacin Sulphate) at Different Temperatures

Conductivity and spectroscopy techniques have been accomplished to comprehend the mechanism of supramolecular assembly of cetyltrimethylammonium bromide (CTAB) and dodecyltrimethylammonium bromide (DTAB) in aqueous solution of amikacin sulphate (0.001, 0.005, and 0.010 mol kg⁻¹). For CTAB, the normal boost of the CMC value with rise in temperature manifests the significant role of aquaphilic dehydration. However, the aquaphobic dehydrations become prominent with temperature and depict typical U-shaped behavior of CMC for DTAB. The thermodynamic parameters of micellization have been derived from CMC values. The outcomes have been conferred in terms of solvation of hydrophobic part of surfactants by hydrophobic part of amikacin sulphate and micellization becomes more favorable for surfactant with more hydrophobic character in the presence of drug. The alteration in micro-environment of the ternary (drug/surfactant/water) system has been explained in terms of fluorescence emission intensity of surfactant solutions which has been found to decrease by the addition of drug. The obtained absorbance spectrum by varying concentrations of surfactant/drug affords noteworthy information regarding the diverse interactions in studied systems. Moreover, the exhaustive understanding of surfactant micellar behavior have been discussed in consideration of use of surfactants as drug delivery agents and hence to amplify drug bioavailability consequently remodeling its treatment efficacy.     

Comparative study of antifungal effect of green and chemically synthesised silver nanoparticles in combination with carbendazim,mancozeb, and thiram

This study reports synthesis and characterisation of silver nanoparticles and their effect on antifungal efficacy of common agricultural fungicides. Silver nanoparticles were synthesised using biological and chemical reduction methods employing Elettaria cardamomum leaf extract and sodium citrate, respectively. Nanoparticles were then characterised using UV–Visible spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy, and dynamic light scattering (DLS). While XRD assigned particles size of 31.86 nm for green and 41.91 nm for chemical silver nanoparticles with the help of the Debye–Scherrer formula, DLS specified monodisperse nature of both suspensions. Nanoparticles were tested individually and in combination with fungicides (carbendazim, mancozeb, and thiram) against fungal phytopathogens. Silver nanoparticles exhibited good antifungal activity and minimum inhibitory concentration (MIC) was observed in the range of 8–64 µg/ml. Also, they positively influenced the efficacy of fungicides. The mean MIC value (mean ± SD) for combination of all three fungicides with green AgNPs was 1.37 ± 0.6 µg/ml and for chemical AgNPs was 1.73 ± 1.0 µg/ml. Hence, it could be concluded that green AgNPs performed better than chemical AgNPs. Synergy was observed between green AgNPs and fungicides against Fusarium oxysporum. In conclusion, this study reports synthesis of monodisperse silver nanoparticles which serve as efficient antifungal agents and also enhance the fungicidal action of reported agricultural fungicides in combination studies.Inspec keywords: X‐ray diffraction, reduction (chemical), visible spectra, ultraviolet spectra, microorganisms, particle size, nanomedicine, nanofabrication, nanoparticles, agrochemicals, antibacterial activity, transmission electron microscopy, silver, light scattering, scanning electron microscopyOther keywords: antifungal effect, green silver nanoparticles, chemically synthesised silver nanoparticles, carbendazim, mancozeb, thiram, antifungal efficacy, common agricultural fungicides, biological reduction methods, chemical reduction methods, transmission electron microscopy, XRD assigned particles size, chemical silver nanoparticles, green AgNPs, chemical AgNPs, monodisperse silver nanoparticles, antifungal activity, agricultural fungicides, Elettaria cardamomum leaf extract, sodium citrate, UV‐visible spectroscopy, X‐ray diffraction, dynamic light scattering, size 31.86 nm, size 41.91 nm     

Optical humidity sensor based on in situ and ex situ synthesized nAg/0.1%PVP composite coated on self supported PVP substrate

An optical based humidity sensor having linear response (R²?=?0.99) over a wide range (06–94%RH) and high sensitivity is reported using nAg/0.1%PVP nanocomposite. Nanocomposite is prepared using in-situ and ex-situ approaches by chemical reduction method with silver salt (AgNO₃) as precursor, tri sodium citrate as reducing agent and PVP as capping agent. The nanocomposite is dip coated on hydrophilic PVP substrate of 80 µm thickness. The material is characterized by using UV–Vis, TEM and FTIR techniques. UV–Vis and TEM analysis are complementary to each other for exhibiting dependence of particle size on preparation approach ??10 nm (in-situ) to 40 nm (ex-situ). Humidity sensing mechanism is explained on the basis of FTIR spectra. Co-ordination between tertiary nitrogen ( Open image in new window ) and C=O group with nAg particles during nanocomposite formation is evidenced from low humidity FTIR. Breaking of these bonds is evidenced from high humidity FTIR. In/PVP/6-PVP sensors offer higher sensitivity (~?0.68?±?0.04 (1/% RH)) as compared to Ex/PVP/4:5-PVP sensors [~?0.31?±?0.04 (1/% RH)].     

Effects of chitosan and selenium treatments on retention of membrane integrity of guava (Psidium guajava L.) fruits during storage

The present study showed the effect of chitosan and selenium on membrane lipids and fatty acids of guava fruits during storage. The fruits were treated with selenium (0.02 ppm), chitosan (1.5%), and a combination of both and stored at room temperature (20 ± 2°C) and low temperature (5 ± 2°C). The membrane integrity was assessed by analyzing lipid constituents and fatty acids. Moreover, the activity of lipoxygenase was also determined. The total lipids were decreased in correlation with a reduction of polar and nonpolar lipids. In addition, unsaturation index of fatty acids also decreased by 3.7% and 8.9% at low and room temperatures, respectively. The treated fruits showed reduced lipid peroxidation as indicated by 21% lower activity of lipoxygenase enzyme. However, fruits stored at low temperature maintained 18% more lipids. The combined treatment of selenium and chitosan with low temperature storage was effective in the protection of membrane integrity.     

A viable technology to generate third‐generation biofuel

First generation biofuels are widely available because the production technologies are well developed. However, growth of the raw materials conflicts with food security, so that first‐ generation biofuels are not so promising. The second generation of biofuels will not compete directly with food but requires several energy intensive processes to produce them, and also increases land‐use change, which reduces its environmental and economic feasibility. The production of third‐generation biofuels avoids the issues met with first‐ and second‐ generation biofuels, namely food–fuel competition, land‐use change, etc., and is thus considered a viable alternative energy resource. On all dimensions of sustainability (environmental, social and economical), a life cycle assessment approach is most relevant to avoid issues in problem shifting. The utilization of organic waste and carbon dioxide in flue gases for the production of biomass further increases the sustainability of third generation biofuels, as it minimizes greenhouse gas emissions and disposal problems. Copyright © 2011 Society of Chemical Industry