Mahesh Ganesapillai

Bio: Mahesh Ganesapillai is an academic researcher from VIT University. The author has contributed to research in topics: Adsorption & Activated carbon. The author has an hindex of 13, co-authored 30 publications receiving 453 citations. Previous affiliations of Mahesh Ganesapillai include Aristotle University of Thessaloniki & Anna University.

Recent Developments in Nanomaterials-Modified Membranes for Improved Membrane Distillation Performance.

Abstract: Membrane distillation (MD) is a thermally induced membrane separation process that utilizes vapor pressure variance to permeate the more volatile constituent, typically water as vapor, across a hydrophobic membrane and rejects the less volatile components of the feed Permeate flux decline, membrane fouling, and wetting are some serious challenges faced in MD operations Thus, in recent years, various studies have been carried out on the modification of these MD membranes by incorporating nanomaterials to overcome these challenges and significantly improve the performance of these membranes This review provides a comprehensive evaluation of the incorporation of new generation nanomaterials such as quantum dots, metalloids and metal oxide-based nanoparticles, metal organic frameworks (MOFs), and carbon-based nanomaterials in the MD membrane The desired characteristics of the membrane for MD operations, such as a higher liquid entry pressure (LEPw), permeability, porosity, hydrophobicity, chemical stability, thermal conductivity, and mechanical strength, have been thoroughly discussed Additionally, methodologies adopted for the incorporation of nanomaterials in these membranes, including surface grafting, plasma polymerization, interfacial polymerization, dip coating, and the efficacy of these modified membranes in various MD operations along with their applications are addressed Further, the current challenges in modifying MD membranes using nanomaterials along with prominent future aspects have been systematically elaborated

Empirical modeling of drying kinetics and microwave assisted extraction of bioactive compounds from Adathoda vasica and Cymbopogon citratus

Abstract: To highlight the shortcomings in conventional methods of extraction, this study investigates the efficacy of Microwave Assisted Extraction (MAE) toward bioactive compound recovery from pharmaceutically-significant medicinal plants, Adathoda vasica and Cymbopogon citratus. Initially, the microwave (MW) drying behavior of the plant leaves was investigated at different sample loadings, MW power and drying time. Kinetics was analyzed through empirical modeling of drying data against 10 conventional thin-layer drying equations that were further improvised through the incorporation of Arrhenius, exponential and linear-type expressions. 81 semi-empirical Midilli equations were derived and subjected to non-linear regression to arrive at the characteristic drying equations. Bioactive compounds recovery from the leaves was examined under various parameters through a comparative approach that studied MAE against Soxhlet extraction. MAE of A. vasica reported similar yields although drastic reduction in extraction time (210 s) as against the average time of 10 h in the Soxhlet apparatus. Extract yield for MAE of C. citratus was higher than the conventional process with optimal parameters determined to be 20 g sample load, 1:20 sample/solvent ratio, extraction time of 150 s and 300 W output power. Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy were performed to depict changes in internal leaf morphology.

Study the effect of sun, oven and microwave drying on quality of onion slices

Abstract: Sun, oven (50 and 70 °C) and microwave oven (210 and 700 W) drying of onion slices were carried out to monitor the drying kinetics and quality degradation of the product. Page, “Modified Page” and “Midilli and Kucuk” models exhibited high coefficient of determination (R2) values, ranging between 0.994 and 0.999. The calculated effective diffusivity (Deff) values (m2/s) of onion slices for the sun, oven 50 °C and oven 70 °C, microwave 210 W and microwave 700 W drying process were 8.339 × 10−10, 7.468 × 10−10, 1.554 × 10−9, 4.009 × 10−8 and 4.869 × 10−8, respectively. Fresh and dried onion slices had high amounts of K (696.82–16357.55 mg/kg), Ca (69.64–340.03 mg/kg), Na (37.72–1895.43 mg/kg), Mg (3.31–964.77 mg/kg) and P (46.47–3384.07 mg/kg) minerals. The highest mineral values were determined in oven dried samples. Sun (L∗ 58.00 ± 4.83, a∗ 0.27 ± 0.10, b∗ 14.36 ± 2.40) and microwave oven drying (210 W) (L∗ 54.78 ± 7.54, a∗ −0.71 ± 0.09, b∗ 13.17 ± 1.05) revealed better colour values in the dried products. The phenolic contents of microwave oven dried samples (1664.39 ± 134.12 and 1623.59 ± 140.02 for 210 W and 700 W, respectively) were higher than those of the other dried onion slices.

Green technologies for the extraction of bioactive compounds in fruits and vegetables

Abstract: Bioactive compounds are extracted from natural sources and they have beneficial effects on human health. Fruits and vegetables are rich in carotenoids, phenolic compounds, Vitamin C, among others. Extraction processes for these compounds depend on several factors such as the technique that is used, the raw material, and the organic solvent. Conventional techniques generally require large amounts of organic solvents, high energy expenditure, and are time consuming, which has generated interest in new technologies that are referred to as clean or green technologies. These can reduce or eliminate the use of toxic solvents, and thus preserve the natural environment and its resources. The aim of this review is to discuss recent techniques used to extract bioactive compounds from natural sources, in order to reduce the economic and ecological impact of these processes.

A Review on Thin-Layer Drying-Curve Equations

Abstract: This paper presents a comprehensive review of thin-layer drying-curve models available in the literature and their comparisons for single-layer drying applications from 2003 to 2013. In this regard, a total of 67 models are selected and classified under 28 performance assessment criteria for comparison purposes. These models are then evaluated by considering the following parameters: (1) product type; (2) pretreatment type; (3) drying parameters, such as temperature, air velocity, layer thickness, microwave power levels, amount of solar radiation, vacum pressure, frequency of sound wave, excitation amplitude, relative humidity, bed depth, product shape, pH, salt content, absolute pressure, etc.; and (4) drying method employed. Furthermore, the best models obtained are employed for product drying applications and compared for different drying methods, drying parameters, and dried products.