Jadavpur University

About: Jadavpur University is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Population & Schiff base. The organization has 10856 authors who have published 27678 publications receiving 422069 citations. The organization is also known as: JU & Jadabpur University.

Influence of Hall current on radiative nanofluid flow over a spinning disk: A hybrid approach

Abstract: The present literature exhibits the features of Hall current on hybrid nanofluid flow over a revolving disk. Impacts of magnetic field and thermal radiation have been also included to explore the fine points of the flow. An innovative class of nanofluid i.e. hybrid nanofluid is being used here, which are assemble of Copper (Cu) and Titanium Dioxide ( T i O 2 ) with water. The foremost PDE equations of our model are renovated into ODEs by employing similarity variables and then sketched out via RK-4 method in conjunction with shooting procedure. Impact of embedding flow factors on velocity, temperature, concentration have been framed in the light of parametric study. Favorable comparison with existing literatures has been revealed and it depicts tremendous similarity. Result addresses that radial skin frictional factor is enhanced for Hall parameter, while transverse frictional component illustrates opposite scenario. Investigation extracts that temperature declines for Hall parameter and heat transport rises for radiative factor. Also, hybrid nanosuspension exhibits elevated temperature profile than usual nanoliquids.

Characterizing foreground for redshifted 21 cm radiation: 150 MHz Giant Metrewave Radio Telescope observations

Abstract: Foreground removal is a major challenge for detecting the redshifted 21 cm neutral hydrogen (H i) signal from the Epoch of Reionization. We have used 150 MHz Giant Metrewave Radio Telescope observations to characterize the statistical properties of the foregrounds in four different fields of view. The measured multifrequency angular power spectrum Cl(Δν) is found to have values in the range 104–2 × 104 mK2 across 700 ≤ l ≤ 2 × 104 and Δν ≤ 2.5 MHz, which is consistent with model predictions where point sources are the most dominant foreground component. The measured Cl(Δν) does not show a smooth Δν dependence, which poses a severe difficulty for foreground removal using polynomial fitting. The observational data were used to assess point source subtraction. Considering the brightest source (∼1 Jy) in each field, we find that the residual artefacts are less than 1.5 per cent in the most sensitive field (FIELD I). Considering all the sources in the fields, we find that the bulk of the image is free of artefacts, the artefacts being localized to the vicinity of the brightest sources. We have used FIELD I, which has an rms noise of 1.3 mJy beam−1, to study the properties of the radio source population to a limiting flux of 9 mJy. The differential source count is well fitted with a single power law of slope −1.6. We find there is no evidence for flattening of the source counts towards lower flux densities which suggests that source population is dominated by the classical radio-loud active galactic nucleus. The diffuse Galactic emission is revealed after the point sources are subtracted out from FIELD I. We find Cl ∝ l−2.34 for 253 ≤ l ≤ 800 which is characteristic of the Galactic synchrotron radiation measured at higher frequencies and larger angular scales. We estimate the fluctuations in the Galactic synchrotron emission to be at l = 800 (θ > 10 arcmin). The measured Cl is dominated by the residual point sources and artefacts at smaller angular scales where Cl ∼ 103 mK2 for l > 800.

A review on the application of different treatment processes for emulsified oily wastewater

Abstract: Oily wastewater, one of the major threats to environment nowadays, mainly originates from petrochemical, heavy metal, food processing, paint, automobile industrial premises. This oil contaminated wastewater is mutagenic and carcinogenic to human health as well as inhibitory to plant growth. Without any proper treatment if such oily water stream disposed into water bodies, apart from increasing the BOD and COD, it also imparts a sunlight impervious layer at the top of the stream restricting the entrance of sunlight followed by disruption of aquatic ecosystem. Hence proper treatment of oily wastewater before its discharge to environment is one of the primary concerns. Researchers have used several technologies such as, gravity sedimentation, coagulation, flotation, coagulation composite flotation, demulsification, membrane separation, flocculation, chemical precipitation and bioremediation have been explored to purify this oil contaminated wastewater to a desired level. Especially, the uniqueness of the treatment will require a through merit analysis of the process, when the wastewater comprises of oil–water emulsion. Hence, in this review an analytical insight on the merits of the process for the treatment of such emulsified system has been provided. The review article also discusses different microorganisms that are required for bioremediation of either oil spill over a large aquatic zone or oil–water emulsion at source point. Finally, the manuscript highlighted some of the effluent treatment plants’ operational process from different industries, which might provide a typical understanding of a comparative view between different treatment processes.

Muddy Roll-up Structures in Siliciclastic Interdune Beds of the c. 1.8 Ga Waterberg Group, South Africa

Abstract: Concentrically rolled-up silty mudrock laminae, 1–2 mm thick, are found in the uppermost of four, 40–110 cm thick interdune beds within a thick aeolian succession of the c. 1.8 Ga Makgabeng Formation, Waterberg Group, South Africa. These curved laminae are analogous to previously described “roll-ups,” biogenic structures generally ascribed to soft-sediment deformation or desiccation of microbial mats overlying either carbonate or siliciclastic sediments, within shallow- to deep-marine paleoenvironments. The Makgabeng roll-ups are thought to reflect desiccation of a microbial mat, followed by resedimentation of cohesive, discrete, curled mat fragments. Their alignment is considered to be the result of an extreme precipitation event. The significance of the South African example of roll-ups is that they appear to have formed within a fully terrestrial paleoenvironment, in one of the oldest known Precambrian deserts. Thus, they represent the oldest evidence for microbial colonisation of a terrestrial setting.