Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions

The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.Comment: 31 pages, 11 figure

Isolation, identification, and characterization of resistant bacteria to antibiotics from pharmaceutical effluent and study of their antibiotic resistance

Pharmaceutical effluents primarily enter aquatic environments through the discharge of treated and untreated wastewater from various sources, including hospitals, pharmaceutical manufacturing facilities, and households. Microbes sourced from pharmaceutical effluents such as Pseudomonas spp. pose a significant public health concern because of their high levels of resistance to multiple drugs and extreme multidrug resistance. Therefore, the present study was conducted for the isolation, identification, and molecular characterization of selected isolates from pharmaceutical effluents and also determined their antibiotic sensitivity patterns. From June 2016 to March 2017, a study was conducted on four well-known pharmaceutical companies specializing in antibiotic production in Dhaka and Gazipur. Four wastewater samples were collected from various origins and then brought to the Bacteriology laboratory for microbiological examination. Twelve pure isolates were obtained and characterized through cultural and biochemical tests while molecular identification of Pseudomonas spp. was performed using the 16S rRNA gene sequence. Twelve commercially available antibiotics were used for antibiotic sensitivity tests using Kirby-Bauer disk diffusion methods. We isolated the most predominant isolates, Pseudomonas aeruginosa (41.67%), followed by Bacillus spp. (33.33%) and Staphylococcus spp. (25%) respectively. Among 12 antibiotics, ciprofloxacin is 100% sensitive against P. aeruginosa, while the remaining 11 antibiotics are 100% resistant. Bacillus spp. showed 100% resistance to all antibiotics while 50% sensitive to vancomycin and 100% to chloramphenicol, respectively. Staphylococcus spp. was 100% resistant to all antibiotics. Our research suggested that P. aeruginosa is the reservoir of antibiotic resistance genes and spreads disease to humans from the environment. The findings of this study, i.e., the isolation, identification, and characterization of antibiotic-resistant bacteria from pharmaceutical effluent have highlighted, comprehended, and mitigated the dissemination of antibiotic resistance and opportunistic bacteria

Physical hydrodynamic propulsion model study for creeping viscous flow through a ciliated porous tube

The present investigation focuses on a mathematical study of creeping viscous flow induced by metachronal wave propagation in a horizontal ciliated tube containing porous media. Creeping flow limitations are imposed i.e. inertial forces are small compared with viscous forces and therefore very low Reynolds number (Re<<1) is taken into account. The wavelength of metachronal wave is also considered as very large for cilia movement. The physical problem is linearized and exact solutions are developed for the differential equation problem. Mathematica software is used to compute and illustrate numerical results. The influence of slip parameter and Darcy number on velocity profile, pressure gradient and trapping of bolus are discussed with the aid of graphs. It is found that with increasing magnitude of slip parameter the trapped bolus inside the streamlines increases in size. The study is relevant to biological propulsion of medical micro-machines in drug delivery

In vitro shoot micro propagation of medicinal applications and ornamental value of Cestrum nocturnum L.

This article was published in the Indian Journal of Science and Technology [© 2016 Indian Society for Education and Environment ] and the definite version is available at : http://doi.org/10.17485/ijst/2016/v9i15/86233 The Journal's website is at: http://www.indjst.org/index.php/indjst/article/view/86233Background/Objectives: Cestrum nocturnum L. a night Blooming jasmine belongs to Solanaceae family widely circulated all over tropical as well as subtropical areas of the World. It is mainly popular for ornamental fragrant flowering and hedge plant but also sometimes for traditional medicinal purpose. Due to strongest smelling characteristics of the plants, it is used in many industries for making Perfumes, essential Oils, Soaps, Candles, Body Oils, etc. The existence of natural plants of economic importance are threatened due to rapid urban development, including industrialization, residential development, educational, commercial etc., reduce the land for cultivation. Hence plant tissue culture protocol may be adapted for production and utilization of economically popular plants, including C. nocturnum involving limited space and short period of time. Methods: Shoot tip explants of naturally grown C. nocturnum were excised sterilized and endued on 'Murashige and Skoog' (MS) medium enriched changed concentration of BA, NAA, as well as GA3 singly or in combination. Excised micro shoots were examined for root development on 0.5 MS using IBA, NAA as well as IAA separately. Findings: The highest amount of multiple bud were observed in low concentration of BA (01.50 milligram × l-1), resulted no. of shoot 4.40 as well as 4.20/explant, no. of leaves 15.40 as well as 4.20/explant as well as size of different shoot 5.360 as well as 4.860 cm. The concentration of IBA and IAA were found to be best for root formation in micro shoots (13.20, 6.80 roots/micro shoots) as well as root size (8.39, 5.73 cm) individually. Application: There are many opportunity of plant tissue culture which offer marvelous chances in plant propagation, plant development as well as creation of plants with necessary agronomical features. Finally often hardening plantlets were gradually adjusted to natural condition and acclimatized with 90% success. This established protocol could help plant cell biotechnology, horticulture, medical and industrial sector of the country.Publishe