Color Kinetics During Ripening of Indian Mangoes

During ripening of mangoes, color change kinetics were studied with Alphonso, Banganapalli, and Neelam varieties. The internal and external color change was recorded using CIE-Lab color coordinates. L, a, b, and total color difference (ΔE) values were measured for internal pulp and external peel during the ripening period. Four kinetic models viz. zero order, first order, fractional conversion, and logistic models were used for modeling using MATLAB. Among the explored models, the logistic model was found to be more suitable to predict the changes in all external color coordinates in all the three varieties. Internal color coordinates of different varieties were exhibited contrasting behavior. So different kinetic models were proposed to predict the internal color change for different variety. The fractional conversion model was found to be not suitable in color change kinetics during ripening of mango.     

INVESTIGATION ON MAMMOGRAPHIC IMAGE COMPRESSION AND MICROCALCIFICATION ANALYSIS USING MULTIWAVELETS AND NEURAL NETWORKS

In digital mammography, the resulting electronic image is very large in size, which poses a significant challenge to the transmission, storage, and manipulation of images. Microcalcification is one of the earliest signs of breast cancer, and it tends to appear in small-sized, low-contrast radiopacities in the high-frequency spectrum of a mammographic image. Scalar wavelets excel multiwavelets in terms of peak-signal-to-noise ratio (PSNR), but fail to capture high-frequency information. This study proposes mammographic image compression and microcalcification detection in original and compressed reconstructed images using multiwavelets and neural networks. It also details the classification results obtained through the multiwavelet-based scheme in comparison with the existing scalar wavelet-based scheme. For a testing sample of 30 images, the proposed classification scheme outperforms the scalar wavelet-based classification by a sensitivity of 2.23% and specificity of 3.4% for original (uncompressed) images. Also, it increases the sensitivity by 2.72% and specificity by 8.4% for compressed reconstructed images. This increase in sensitivity and specificity demonstrates a better performance of the proposed detection scheme.     

Green synthesis of metal nanoparticles loaded ultrasonic‐assisted Spirulina platensis using algal extract and their antimicrobial activity

The synthesis of metal nanoparticles (NPs) loaded on the ultrasonic‐assisted Spirulina platensis (MNPs/UASP) was investigated using the green synthesis method. The S. platensis algal extract was taken as a reducing agent. The formations of metal NPs were characterised using UV–visible spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The antimicrobial activity of different metal NPs demonstrated various inhibitory activities against one gram‐positive bacteria (Staphylocicus aureus), four gram‐negative bacteria (Klebsiella pneumonia, Proteus vulgaris, Pseudomonas aeruginosa and Escherichia coli) and one fungus (Aspergillus niger). Both CrNPs/UASP and ZnNPs/UASP show good antimicrobial activity when compared with other MNPs/UASP against microorganisms. This MNPs/UASP is effective in preventing and treating the microbial infection and water pollution in the environment.Inspec keywords: antibacterial activity, nanoparticles, nanomedicine, ultraviolet spectra, visible spectra, microorganisms, Fourier transform infrared spectraOther keywords: metal nanoparticles loaded ultrasonic‐assisted Spirulina platensis, algal extract, antimicrobial activity, green synthesis method, UV–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, gram‐positive bacteria, Staphylocicus aureus, Klebsiella pneumonia, Proteus vulgaris, Pseudomonas aeruginosa, Escherichia coli, Aspergillus niger, fungus, microorganisms, microbial infection, water pollution     

Pretreatment of second and third generation feedstock for enhanced biohythane production: Challenges,recent trends and perspectives

In the context of biofuel production and achieving sustainable bioeconomy, the use of lignocellulosic and algae biomass in anaerobic fermentation processes yields biohythane that has a typical composition of 10–15% H₂, 50–55% CH₄ and 30–40% CO₂. Using organic biomass-based substrates has been shown to minimize environmental impacts due to the versatile production of high-value products under normal operating conditions that are practically achievable. However, the biohythane yield depends on different factors such as the biomass type, the organic loading rate, soluble metabolic products formed, the type of fermentation (single/dual stage) and the pretreatment strategy adopted for the biomass. Different pretreatment strategies based on physical, chemical and biological processes have been proposed in the literature. In this review, improvements in biohythane yield as a result of these pretreatment strategies, the need/effect of inoculum enrichment, the effects of pH, temperature, trace element addition and organic loading rate has been reviewed. Finally, the major developments of improving biohythane yield due to the addition of co-substrates and the current trends are discussed.     

STUDIES ON STIFLING AND DRYING OF COCOONS FOR LONGER STORAGE

ABSTRACT

Long term storage of stifled cocoons is an important problem during unfavourable seasonal conditions. Cocoons could be stifled within 20 minutes by using steam al 90°C. The shade drying of steam stifled cocoons in thin layers reduced the moisture content from 228 per cent (db) to 3 1.7 per cent (db) within 10 days. By hot air conditioning method the cocoons could be stifled and dried simultaneously. Using hot air at 90°C the cocoons could be stifled within 10 minutes, and dried to the equilibrium moisture content within 2 hours. The cocoons stifled by the hot air conditioning method could be reeled even just after stifling.     

Innovative multi‐processed N‐doped carbon and Fe3O4 cathode for enhanced bioelectro‐Fenton microbial fuel cell performance

A novel bioelectro‐Fenton microbial fuel cell (BEF‐MFC) cathode has been fabricated by modification of electrode using multi‐processing of nitrogen‐doped carbon (NDC)/nano‐Fe₃O₄ method with the aims of cost‐effectiveness, high oxygen reduction reaction (ORR) efficiency, and power performance enhancement. In this study, BEF‐MFC with carbon cloth (CC) cathode pyrolyzed with NDC‐M100/Fe₃O₄ at 700°C achieved higher ORR activity compared with the commercial Pt/C under same operational conditions. It also exhibited excellent crystalline structure according to high‐resolution transmission electron microscope (HRTEM) analysis. Moreover, using NDCN/Fe₃O₄ can facilitate further Fenton‐like reaction for the treatment of wastewater. Chemical oxygen demand (COD) removal efficiency of the reactor was 78% with maximum power density of 1.57 W/m³ in 216 hours. Thus, an innovative multi‐processing method with feasibility for enhanced wastewater treatment and improved power performance of the MFC was investigated. This can be effectively applied in related alternative energy production techniques and bio‐electrochemical systems in the future.     

Indane‐based bismaleimide and cloisite 15a nanoclay blends: Kinetics of thermal curing and degradation of particulate nanocomposites

Bismaleimide, 5(6)‐maleimide‐1(4′‐maleimidophenyl)‐1,3,3′‐trimethyl indane (BMII) was prepared, different weight ratios (1, 3, 5, 7, and 9%) of cloisite 15a were blended with BMII ultrasonically and thermally polymerized at 230°C for 6 h. The Fourier transform infrared spectrophotometry (FTIR) studies of the polymerized materials reveal that the clay particles affect only the indane nucleus present in the bismaleimide. Differential scanning calorimetry results reveal that the nanoclay particles affect the enthalpy of curing and the extent of this effect depends on the degree of clay loading. In the case of particulate nanocomposites, irrespective of the amount of clay loading, the endset degradation temperatures of the nanocomposites were found to increase (35–60°C). The change noted in the apparent activation energies (E_a) for curing and degradation with respect to the extent of the reaction (α) is much dependent on the amount of cloisite 15a present in BMII. The TG‐FTIR studies showed the compounds such as CO, CO₂, aromatic amine, and aromatic isocyanates are the major degradation products from polyBMII. Possible degradation mechanism of polyBMII is presented and discussed. The scanning electron microscopy results show that the aggregation of clay particles are noted for higher level loadings (5 and 7%) of cloisite 15a nanoclay particles in BMII. POLYM. COMPOS. 34:1279–1297, 2013. © 2013 Society of Plastics Engineers     

Optimization of Microwave-Assisted Extraction of Phenolic Antioxidants from Grape Seeds (Vitis vinifera)

Grape seeds (Vitis vinifera) are rich in phytochemicals that have antioxidant properties. The influence of independent variables such as microwave power (100, 150, and 200 W), extraction time (2, 4, and 6 min), and solvent concentration (30%, 45%, and 60% ethanol) and their interactions on total phenols and the antioxidant activity (1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power (FRAP)) were determined; and the microwave-assisted extraction (MAE) process was optimized using a central composite design. The total phenols that were expressed as gallic acid equivalents (GAE), catechin equivalents (CAT), and tannic acid equivalents (TAE) were significantly influenced by the solvent concentration and the time of extraction. A numerical optimization was carried out to obtain the overall conditions for MAE of phenolic antioxidants from grape seed. The response variables were maximized for 6 min of MAE of grape seed (GS) with 32.6% ethanol at 121 W with a desirability function of 0.947. The predicted extraction yields were 13?±?0.89, 21.6?±?1.59, and 15.9?±?1.32 mg GAE, CAT, and TAE, respectively per gram of GS. The predicted antioxidant activity per gram of dry weight GS was 80.9% for the inhibition of DPPH and 135 μM ascorbic acid equivalents for FRAP test. The predicted response values were significantly correlated with the observed ones as follows: GAE r?=?0.995, CAT r?=?0.990, TAE r?=?0.996, DPPH r?=?0.996, and FRAP r?=?0.996.