Atikur Rahman - Academia.edu (original) (raw)

Papers by Atikur Rahman

Applied Nanoscience, 2014

Journal of Civil & Environmental Engineering, 2013

Micro- and Nanotechnology Sensors, Systems, and Applications VI, 2014

Research Journal for Veterinary Practitioners, 2014

Materials providing broadband light antireflection have applications as highly transparent window... more Materials providing broadband light antireflection have applications as highly transparent window coatings, military camouflage, and coatings for efficiently coupling light into solar cells and out of light-emitting diodes. In this work, densely packed silicon nanotextures with feature sizes smaller than 50 nm enhance the broadband antireflection compared with that predicted by their geometry alone. A significant fraction of the nanotexture volume comprises a surface layer whose optical properties differ substantially from those of the bulk, providing the key to improved performance. The nanotexture reflectivity is quantitatively well-modelled after accounting for both its profile and changes in refractive index at the surface. We employ block copolymer self-assembly for precise and tunable nanotexture design in the range of ~10–70 nm across macroscopic solar cell areas. Implementing this efficient antireflection approach in crystalline silicon solar cells significantly betters the...

Here we report, water vapor driven actuation of polymer nanotubes, embedded in a nanoporous membr... more Here we report, water vapor driven actuation of polymer nanotubes, embedded in a nanoporous membrane with one end attached to a surface deposited thin polymer layer. The nanotube composite shows oscillatory motion when placed near water. Permeation of water vapor through these nanotube embedded membranes is found to be direction dependent. With the water vapor as the driving force, the actuator can lift a mass 1000 times heavier than itself with a change in relative humidity of less than 40%. The actuation mechanism arises due to efficient absorption of water molecules by polymer nanotubes and their rapid evaporation through the surface deposited polymer layer. This actuator can be used as artificial muscle and the direction dependent water transport may help in understanding the activities of transmembrane channels and pumps of biological cells. With the aid of a nanowire generator, the oscillatory motion can be used to generate electricity too.

Applied Physics Letters, 2013

Pierre Lecointre,1,2 Timothée Mouterde,1,2 Antonio Checco,3 Charles T. Black,4 Atikur Rahman,5 Ch... more Pierre Lecointre,1,2 Timothée Mouterde,1,2 Antonio Checco,3 Charles T. Black,4 Atikur Rahman,5 Christophe Clanet,1,2 and David Quéré1,2,* 1Physique et Mécanique des Milieux Hétérogènes, UMR 7636 du CNRS, ESPCI, 75005 Paris, France 2Laboratoire d’Hydrodynamique de l’X, UMR 7646 du CNRS, École polytechnique, 91128 Palaiseau, France 3Mechanical Engineering Department, Stony Brook University, Stony Brook, New York 11794, USA 4Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA 5Department of Physics, Indian Institute of Science Education and Research (IISER)-Pune, Maharashtra 411008, India

Original research article Prevalence and predicting factors of perceived stress among Bangladeshi... more Original research article Prevalence and predicting factors of perceived stress among Bangladeshi university students using machine learning algorithms Rumana Rois 1*, Manik Ray 2, Atikur Rahman 3, and Swapan. K. Roy 4 1 Department of Statistics, Jahangirnagar University, Dhaka, Bangladesh *Corresponding author’s Email: rois@juniv.edu 2 Department of Statistics, Jahangirnagar University, Dhaka, Bangladesh

This present investigation deals with the effect of processing time and concentration of potassiu... more This present investigation deals with the effect of processing time and concentration of potassium permanganate on tensile strength, weight and stiffness of denim garments. Three 100% cotton denim jeans were treated with stone acid wash with the variation of processing time (1.5, 2 & 2.5 minutes) and concentration (1.5, 2& 2.5g/l) of potassium permanganate after typical enzyme bleach wash. Tensile Strength, Weight and Stiffness (bending length) were investigated before and after each treatment (concentration and respective time) according to standard test methods. It was found that change in processing time and concentration reveals big difference of these properties between treated and untreated garments.

International Journal of Clinical Practice

AIM To estimate the prevalence of COVID-19 pandemic and its transmission rates among people in bo... more AIM To estimate the prevalence of COVID-19 pandemic and its transmission rates among people in both community and household levels of Bangladesh. METHODS We use the cross-sectional online survey data of 2080 individuals, collected from 442 households during June to September 2020 in Bangladesh. The Longini and Koopman stochastic epidemic modelling approach was adapted for analyzing the data. To validate the results, a simulation study was conducted using the Markov Chain Monte Carlo (MCMC) method via the Metropolis-Hastings algorithm in the context of Bayesian framework. RESULTS Overall, the prevalence of COVID-19 pandemic was 15.1% (315 out of 2080) among people in Bangladesh. This proportion was higher in smaller households (size one: 40.0%, two: 35.7% and three: 25.9%) than larger (four: 15.8%, five: 13.3%, six: 14.1%, seven: 12.5% eight: 8.7%, nine: 14.8% and ten or eleven: 5.7%). The transmission rate of COVID-19 in community people was higher (12.0%, 95% CI: 10.0% to 13.0%) than household members (9.0%, 95% CI: 6.0% to 11.0%). CONCLUSION The susceptible individuals have a higher risk of community infection than the household and the community transmission is more responsible than the household for COVID-19 pandemic in Bangladesh.

Nanotechnology, Jan 12, 2018

Effect of oxygen on the humidity dependence of photocurrent in the presence of UV light has been ... more Effect of oxygen on the humidity dependence of photocurrent in the presence of UV light has been studied for perovskite solar cells. We observed that the magnitude of photocurrent increases with decreasing humidity initially, but below a certain level, the photocurrent starts to decrease when the humidity is reduced by sending dry nitrogen gas. If we decrease the humidity by sending dry air (keeping nitrogen to oxygen ratio same), then this effect is absent. This phenomenon is related to the presence of oxygen in the environment. When humidity is decreased by flowing dry nitrogen, the oxygen present in the environment of perovskite solar cell also reduces. We found that in the reduced oxygen condition, the presence of UV light helps to remove oxygen from the surface of the mesoporous TiO2 which is responsible for the reduction of photocurrent. In the presence of white light, this effect is not observed. To understand the phenomenon we studied low-frequency noise and current-voltage ...

American Scientific Research Journal For Engineering Technology and Sciences, Feb 19, 2015