Isolation and Characterization of Buffalo Milk Lysozyme

Lysozyme is a commercially valuable enzyme, and is applied in many fields, concerning products such as foods, drugs, and the like. In this work, lysozyme was isolated and purified from buffalo milk using sephadex G-50 and cation exchanger carboxymethyl cellulose. Lysozyme active fractions from buffalo milk were assayed against Gram positive substrate Micrococcus luteus at 450 nm and a decline in absorbance of 0.001 per min was observed. The optimum activity of lysozyme (158.3 ± 1.7 units/mL) was at 7.5 pH and 37°C temperature. Lysozyme activity at pasteurization temperatures 62.5°C, 30 min and 75°C, 15 s were (156.08 ± 1.03 and 156 ± 2 units/mL) not affected significantly; however, 47% activity of lysozyme was reduced at 100°C for 5 min. Antibacterial susceptibility testing of lysozyme (chicken egg white lysozyme and buffalo milk lysozyme) was performed on Micrococcus luteus (ATCC 4698) and Escherichia coli (ATCC 25235). Both lysozymes showed no inhibition effect against Escherichia coli.     

Material properties of ZnS nanoparticles incorporated soy protein isolate biopolymeric film

ABSTRACT

Glycerol plasticised soy protein isolate (SPI) films at different contents (1 to 5% w/w w.r.t SPI) of zinc sulphide (ZnS) nanoparticles were fabricated. Before the film formation, the ZnS nanoparticles incorporated SPI suspensions were subjected to molecular mass studies by SDS-PAGE and specific conductivity studies. SPI films and ZnS nanoparticles incorporated SPI films were structurally and mechanically characterised by Fourier transform infrared spectroscopy (FT-IR) and mechanical properties, respectively. Transmittance and water uptake studies were also carried out for ZnS nanoparticles incorporated SPI films. The results from transmittance, water uptake and FT-IR studies indicated a good compatibility between the ZnS nanoparticles and the SPI. With the increase in the contents of ZnS nanoparticles from 0 to 4%, the tensile modulus increased from 87.4 to 99?MPa. The water uptake decreased significantly from 159 to 10.76%. However, the results showed the absence of antibacterial effect in ZnS nanoparticles incorporated SPI film.     

Caught between a rail and a hard place: a two-country meta-analysis of factors that impact Track Worker safety in Lookout-related rail incidents

Abstract

The last 15?years has witnessed a surge in rail-related human factors research but little has examined the Track Worker role. Track work often takes place whilst trains are running under the protection of Lookouts who provide warning of approaching trains. Despite—or perhaps because of—these measures, there is a notable prevalence of incidents involving Lookouts, warranting a closer look at the nature of their task and the wider sociotechnical system (STS) to identify what may be learned for railway safety management. A systematic review of incident reports involving Lookouts was undertaken on Australian and UK rail incidents from 2006 to mid-2018 with a qualitative meta-analysis (n?=?31) revealing nine factors corresponding with STS dimensions at the organisational, social, task and individual level. Much of the risk lay in the set up and implementation of Lookout working, and in Track Worker group dynamics—factors endemic to working whilst trains are running—rather than specific to the Lookout, with such factors arguably applicable across other Track Worker groups. Findings point to a need for more targeted research into the STS aspects of track working, as well as improving the training and/or procedures of those managing the Lookout protection system of work.     

Psychological factors for driver distraction and inattention in the Australian and New Zealand rail industry

A signal passed at danger (SPAD) event occurs when a train moves past a stop signal into a section of unauthorised track. SPAD events are frequently attributed to driver distraction and inattention, but few studies have explored the failure mode from the perspective of task demand and the ability of the driver to self-regulate in response to competing activities. This study aimed to provide a more informed understanding of distraction, inattention and SPAD-risk in the passenger rail task. The research approach combined focus groups with a generative task designed to stimulate situational insight. Twenty-eight train drivers participated from 8 different rail operators in Australia and New Zealand. Data were analysed thematically and revealed several moderating factors for driver distraction. Time-keeping pressure and certain aspects of the driver-controller dynamic were considered to distort performance, and distractions from station dwelling and novel events increased SPAD-risk. The results are conceptualised in a succinct model of distraction linking multiple factors with mechanisms that induced the attentional shift. The commonalities and inter-dynamics of the factors revealed insight into driving anxiety in the passenger rail mode, and suggested that SPAD-risk was intensified when three or more factors converged. The paper discusses these issues in the context of misappropriated attention, taxonomic implications, and directions for future research.     

Comprehensive Review on Silicon-enhanced Green Nanocomposites Towards Sustainable Development

Silicon - The demand for the development of high-performance and eco-friendly nanocomposites is soaring up. This is because of their desired mechanical, thermal, electrical, magnetic, catalytic,...     

Lactobacillus acidophilus: Characterization of the Species and Application in Food Production

L. acidophilus is a homofermentative, microaerophilic, short chain gram positive microorganism with rod morphology having its bacteriocins belonging to class II a. Several bacteriocins of L. acidophilus have been isolated and characterized. These are structurally similar, but their molecular weight varies as well as their spectrum of antimicrobial activity. They exhibit important technical properties, i.e., thermostability and retaining of activity at a wide pH range along with strong inhibitory actions against food spoilage and pathogenic bacteria make them an important class of biopreservatives. L. acidophilus can be added as an adjunct in many food fermentation processes contributing to unique taste, flavor, and texture. It also preserves the products by producing lactic acid and bacteriocins. A lot of new information regarding the bacteriocins of L. acidophilus has emerged during the last few years. In this review, an attempt has been made to summarize and discuss all the available information regarding the sources of bacteriocins production, their characteristics, and their antimicrobial action along with their application.     

Morphological and structural analysis of nano-structured gold thin film on silicon by pulsed laser deposition technique

Structural and morphological investigations on optimized nano-structured gold thin film (under vacuum ∼10⁻³ Torr) are reported. The Au optimized thin film was deposited on 4 N polished and analytic grade p-type single crystal (111) Silicon wafer by pulsed laser deposition (PLD) technique, under a vacuum of about 10⁻³ Torr at room temperature. The space resolved dynamics of the plume is studied by analyzing CCD images of plume. Average size of deposited nanoparticles is along the preferred (111) orientation is ∼ 20 nm using PLD technique. The deposited film is non-uniform with particle size within the range of 6.19 nm-19.62 nm. There is decrease in the value of dislocation line density. XRD and SEM investigations support each other.     

Development of membranes by radiation grafting of acrylamide into polyethylene films: Properties and metal ion separation

Polyethylene‐g‐polyacrylamide membranes were prepared by graft polymerization of acrylamide into polyethylene films using a preirradiation technique. The membranes showed good swelling in water and a maximum of 232% swelling was achieved for a graft level of 590%. The electrical resistance of the membranes decreased with increase in the degree of grafting to 200% and then stabilized with a further increase in grafting to 590%. The membranes had an excellent binding capacity for mercury ions. Almost 99% mercury separation was achieved from a metal solution of 200 ppm. The metal binding capacity increased with increase in the degree of grafting in the membranes. A binding capacity as high as 6.2 mmol/g in a membrane with 590% grafting was achieved. The pH of the metal solution did not have any significant influence on the binding ability of the membranes. The mercury‐loaded membranes showed better thermal stability as compared to those without metal binding. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 282–291, 2002     

Hydrodynamics of longitudinally discontinuous,vertically double layered and partially covered rigid vegetation patches in open channel flow

The aim of this paper is to numerically investigate how the flow structures are affected through a longitudinally discontinuous and vertically two‐layered vegetation occupying half width of the channel, with steady flow rate and subcritical conditions. A three‐dimensional (3‐D) Reynolds stress turbulence model (RSM), incorporated by Computational Fluid Dynamics (CFD) code FLUENT, was first validated with the experimental data, and then used for simulation purpose. The results showed that the flow stream‐wise velocities within the gap regions are visibly slower than that in the vegetation patch regions. Along the cross section, the velocity in the vegetation region (VR) reduced significantly due to resistance offered by the vegetation, which affected the channel conveyance; as compared to the free (non‐vegetated) region. The flow instability in the lateral direction was triggered by the flow shear due to the presence of partly distributed vegetation, resulting in the formation of coherent vortices and exchange of momentum at the interface. The discharge percentage passing through the free region (FR) was found to be 144–525% larger than that passing through the VR. The flow resistance increased significantly with higher vegetation density, whereas it decreased when both the vegetation layers were submerged. Moreover, the flow characteristics profiles in large gaps were more stable than in small gaps. The turbulent kinetic energy (TKE) and turbulence intensity also increased significantly through the patch regions compared to that of the gap regions. The results indicated that the flow structures and the flow resistance are strongly influenced by partial and discontinuous vegetation.     

Development of antimicrobial polypropylene sutures by graft polymerization. I. Influence of grafting conditions and characterization

Modification of polypropylene monofilament was carried out by the graft polymerization of 1‐vinylimidazole (VIm) using simultaneous radiation grafting method. The effect of radiation dose, monomer concentration, and the grafting medium on the degree of grafting was evaluated. It was observed that the presence of organics as additives in the reaction medium had significant influence on the graft levels. These grafted sutures were characterized using several techniques, such as infrared spectroscopy (IR), X‐ray diffraction, and differential scanning calorimetry (DSC). It was found that the grafts are confined to the amorphous region of the monofilament and the crystalline regions remain intact. The surface morphology of sutures was evaluated by scanning electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3895–3901, 2006