EFFECT OF DRYING ON FLUIDISATION BEHAVIOUR OF PACKED BEDS OF SHREDDED COCONUT

Drying of shredded coconut is usually carried out commercially in order to facilitate storage over reasonable periods of time and to obtain advantages of reduction of weight and volume in transport and packaging. Fluidised bed drying of materials is generally accepted to be an efficient method of drying. Experiments were carried out to investigate the behaviour of fluidisation of shreddet coconut at various moisture contents. The pressure drop was measured across random packings of shredded coconut. It is seen that shredded coconut does not fluidise easily at moisture contents greater than 0.55 (55 weight percent moisture). It is also seen that fluidisation can be easily achieved by drying shredded coconut to moisture contents between approximately 0.25 to 0.55. The pressure drop characteristics within this region is seen to closely resemble the theoretical behaviour of a fluidised bed. It is also seen that particles of shredded coconut in beds of moisture contents less than 0.25 tend to undergo pneumatic transport if efforts are made to fluidise such beds.     

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.     

A green chemistry approach for synthesizing biocompatible gold nanoparticles

Gold nanoparticles (AuNPs) are a fascinating class of nanomaterial that can be used for a wide range of biomedical applications, including bio-imaging, lateral flow assays, environmental detection and purification, data storage, drug delivery, biomarkers, catalysis, chemical sensors, and DNA detection. Biological synthesis of nanoparticles appears to be simple, cost-effective, non-toxic, and easy to use for controlling size, shape, and stability, which is unlike the chemically synthesized nanoparticles. The aim of this study was to synthesize homogeneous AuNPs using pharmaceutically important Ganoderma spp. We developed a simple, non-toxic, and green method for water-soluble AuNP synthesis by treating gold (III) chloride trihydrate (HAuCl₄) with a hot aqueous extract of the Ganoderma spp. mycelia. The formation of biologically synthesized AuNPs (bio-AuNPs) was characterized by ultraviolet (UV)-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the biocompatibility of as-prepared AuNPs was evaluated using a series of assays, such as cell viability, lactate dehydrogenase leakage, and reactive oxygen species generation (ROS) in human breast cancer cells (MDA-MB-231). The color change of the solution from yellow to reddish pink and strong surface plasmon resonance were observed at 520 nm using UV-visible spectroscopy, and that indicated the formation of AuNPs. DLS analysis revealed the size distribution of AuNPs in liquid solution, and the average size of AuNPs was 20 nm. The size and morphology of AuNPs were investigated using TEM. The biocompatibility effect of as-prepared AuNPs was investigated in MDA-MB-231 breast cancer cells by using various concentrations of AuNPs (10 to 100 μM) for 24 h. Our findings suggest that AuNPs are non-cytotoxic and biocompatible. To the best of our knowledge, this is the first report to describe the synthesis of monodispersed, biocompatible, and soluble AuNPs with an average size of 20 nm using Ganoderma spp. This study opens up new possibilities of using an inexpensive and non-toxic mushroom extract as a reducing and stabilizing agent for the synthesis of size-controlled, large-scale, biocompatible, and monodispersed AuNPs, which may have future diagnostic and therapeutic applications.     

Tolerance limit of chloride for steel in blended cement mortar using the cyclic polarisation technique

The tolerance limit for chloride in ordinary Portland cement (OPC) and blended cements such as Portland pozzolana cement (PPC) and Portland slag cement (PSC) was assessed by cyclic polarisation. This study covers both cement extracts and mortar. The salient features of this investigation were: in extracts, the tolerance limit for chloride actually doubles for PSC when compared to PPC and OPC. The tolerance limit for chloride for various mortars follows the order: PSC > PPC > OPC. In OPC and PPC mortar, the repassivation potential (E _rep) shifted negatively with higher amounts of free chloride but in PSC mortar E _rep shifted positively (+590 mV) even in the presence of 5,000 ppm of free chloride. PSC takes longer time (50 days) to reach E _rep indicating perfect passivity maintained for the embedded steel.     

A Modified Backpropagation Training Algorithm for Feedforward Neural Networks*

In this paper, a new efficient learning procedure for training single hidden layer feedforward network is proposed. This procedure trains the output layer and the hidden layer separately. A new optimization criterion for the hidden layer is proposed. Existing methods to find fictitious teacher signal for the output of each hidden neuron, modified standard backpropagation algorithm and the new optimization criterion are combined to train the feedforward neural networks. The effectiveness of the proposed procedure is shown by the simulation results. *The work of P. Thangavel is partially supported by UGC, Government of India sponsored project.     

Vaccine requirements for sustained cellular immunity to an intracellular parasitic infection

The humoral immunity induced by many viral and bacterial vaccines mediates protection that is maintained over a long period of time. In contrast, for other intracellular infections (such as with Leishmania major or Mycobacterium tuberculosis) for which cell-mediated immunity is required for protection, the mechanisms for developing durable responses after vaccination have not been well defined. Here we demonstrate that vaccination with plasmid DNA encoding a specific leishmanial antigen is more effective than leishmanial protein plus recombinant IL-12 in eliciting long-term immunity capable of controlling L. major infection. We also show that leishmanial protein plus IL-12 DNA produces an immunity that lasts much longer than does immunity elicited by leishmanial protein plus IL-12 protein, indicating that the persistence of IL-12 may be the essential determinant in maintaining durable cell-mediated immune responses for an intracellular parasitic infection.     

Fabrication of an electrochemical biosensor with ZnO nanoflakes interface for methylglyoxal quantification in food samples

Increased consumption of fried foods such as grilled chicken contains elevated levels of methylglyoxal (MG), which is associated with diabetes mellitus. Hence, in this work, glyoxalase 1(GLO 1) based, zinc oxide (ZnO) flakes interfaced mediator free electrochemical biosensor was developed to detect MG in grilled chicken. ZnO flakes were synthesized by direct precipitation method. X-ray diffractometer and field emission scanning electron microscope were used to study the structural and morphological characteristics of ZnO flakes. The immobilization of GLO 1 on Pt/ZnO flakes modified electrode was confirmed by Fourier transform infrared spectroscopy. Cyclic voltammetric and amperometric studies were carried out using Pt/ZnO flakes/GLO 1 working electrode. The developed biosensor exhibited linear range of 0.6–2.0 µM, sensitivity of 0.281 µA µM^?1, LOD of 9 nM with a response time of <4 s and shelf life of 18 days (89%).     

Increased LRG1 Levels in Overweight and Obese Adolescents and Its Association with Obesity Markers,Including Leptin,Chemerin, and High Sensitivity C-Reactive Protein

Leucine-rich α-2 glycoprotein1 (LRG1) is a member of the leucine-rich repeat (LRR) family that is implicated in multiple diseases, including cancer, aging, and heart failure, as well as diabetes and obesity. LRG1 plays a key role in diet-induced hepatosteatosis and insulin resistance by mediating the crosstalk between adipocytes and hepatocytes. LRG1 also promotes hepatosteatosis by upregulating de novo lipogenesis in the liver and suppressing fatty acid β-oxidation. In this study, we investigated the association of LRG1 with obesity markers, including leptin and other adipokines in adolescents (11–14 years; n = 425). BMI-for-age classification based on WHO growth charts was used to define obesity. Plasma LRG1 was measured by ELISA, while other markers were measured by multiplexing assay. Median (IQR) of LRG1 levels was higher in obese (30 (25, 38) µg/mL) and overweight (30 (24, 39) µg/mL) adolescents, compared to normal-weight participants (27 (22, 35) µg/mL). The highest tertile of LRG1 had an OR [95% CI] of 2.55 [1.44, 4.53] for obesity. LRG1 was positively correlated to plasma levels of high sensitivity c-reactive protein (HsCRP) (ρ = 0.2), leptin (ρ = 0.2), and chemerin (ρ = 0.24) with p < 0.001. Additionally, it was positively associated with plasma level of IL6 (ρ = 0.17) and IL10 (ρ = 0.14) but not TNF-α. In conclusion, LRG1 levels are increased in obese adolescents and are associated with increased levels of adipogenic markers. These results suggest the usefulness of LRG1 as an early biomarker for obesity and its related pathologies in adolescents.     

Competitive role of inhibitive and aggressive ions in the corrosion of steel in concrete

The effect of various inhibitive ions (hydroxide, citrate, stannate) for the corrosion of steel in concrete was studied by weight loss measurements, chronopotential studies, anodic polarization technique and compressive strength tests. The salient features of the investigation were: in 100% OPC as well as in OPC + fly ash (3:1 ratio) extracts the passivity of steel was readily destroyed even by the presence of 10 000 ppm of chloride. However in 100% OPC and also in OPC + fly ash (3:1 ratio) extracts containing inhibitive and complexing agents like hydroxide, citrate and stannate, the passivity of steel was maintained even in the presence of 30 000 ppm of chloride. The addition of inhibitive ions like hydroxide, citrate and stannate not only decreased the corrosion rate of steel in simulated concrete environments but also increased the compressive strength of mortars. Citrates, stannates and CaO are effective inhibitors of the corrosion of steel in concrete.