Recent Research Highlights



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To upload your Research Highlight, please visit http://web.gauhati.ac.in/update/research

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Wind profiling results from GU ST-Radar

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Endophytes and plant growth in tomato

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Photo sensing ZnO-PS:p-Si and NH3 sensing CdS

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Collecting a rare species of flora

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Al-doped ZnO transparent conductors

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Synthesis of magnetic nanocomposites

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Big Bang nucleosynthesis at LHC (CERN)

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Defence mechanism of chickpea pod wall

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Graphene quantum dots moisture sensor

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Valuing fishing activity at Deepor Beel

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 What's in a drink?

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Library metadata timeline

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Looking for a fifth force

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Dust dynamics over lunar surface

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Graphene oxide filter paper

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Free standing polypyrrole film

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 A new fish species from Kameng river stream

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 A new fish species from Diyung river (Assam)

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Ovicidal agents for Aedes aegypti

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Antibacterial activity of Spotted Gum

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Binary stars in King 1 open cluster

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Antibacterial properties of ZnO

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 DFT study of fullerene

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Smartphone to measure chlorophyll

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Erosion study of Subansiri river

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Classification of a new plant species

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Drug-drug & drug-nutraceutical solids

https://sites.google.com/a/gauhati.ac.in/research/#ds11092019 Fractal nature of ZnO nanoparticles
Published on 1 July, 2020
First observation by the GU ST-Radar : Wind profiling to understand thunderstorm dynamics
Manoj Saikia and collaborators report the first observation by the Stratospheric-Tropospheric Radar (ST-Radar) at Gauhati University related to wind profiling in the event of a thunderstorm. The GU ST-Radar is a newly established National facility for atmospheric research. This work is published in the journal Natural Hazards.


Authors
M Devi1,2, S Patgiri1,2, A Medhi1, S Das1, M Saikia1, A K Barbara2, S S Kakatkar3, and K P Ray3
from other organisations

Abstract
The wind profiling features received from recently installed stratospheric-tropospheric (ST) radar of Gauhati University (GU) (26.2 N, 91.75 E) are presented in the paper along with the validation process of the data by using radiosonde-derived wind parameters. The final focus of the paper is directed onto the thunderstorm-related changes in wind fields covering both vertical and composite components. Starting with the seasonal thunderstorm occurrence character over Guwahati through eight years of observations, the importance of the work on this meteorologically sensitive subtropical zone is highlighted. For identifying the process of growth of thunderstorm, the magnitudes of updrafts and downdrafts are extracted from the ST Radar-derived storm-time wind profilings. For evaluation of atmospheric system dynamics, the structure constant 𝐶n2 is calculated through radar Bragg-scattered signals and the resultant modifications induced by the thunderstorm on this parameter are presented and brought into ambit of discussions. The paper finally identifies the storm-induced effects in the wind field-derived variabilities, for possible adaptation as inputs for a thunderstorm predictive model.

Journal Reference


Botany    Botany    https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Endophytes can prevent bacterial wilt disease and promote growth in tomato
Niraj Agarwala and coworkers show how a bacterium isolated from an indigenous plant can help tomato plant growth and prevent infections. This work is reported in Microbiological Research.


Authors
Heena Agarwal, Bhaskar Dowarah, Pooja Moni Baruah, Kuntala Sarma Bordoloi, Debasish B Krishnatreya, and Niraj Agarwala

Abstract
Endophytes are beneficial plant microbes which help the plants by producing various plant growth promoting substances and also by acting as biocontrol agents against various plant pathogens. In the present study, evaluation of endophytic bacteria isolated from Gnetum gnemon, an ethnomedicinal plant was carried out for their plant growth promoting (PGP) activity and antagonistic potential against bacterial wilt pathogen Ralstonia solanacearum. Initially a total of 40 endophytic bacteria were isolated which were clustered into 13 groups based on RFLP and BOX-PCR fingerprinting. These 13 representative isolates belonged to different genera of Bacillus (9), Solibacillus (1), Staphylococcus (2) and Caballeronia (1). Among them, six isolates were positive for production of IAA, the value of which ranged from 11.16 to 27.63 μg mL−1. Phosphate solubilisation in the range of 106.4 to –212.7 μg mL−1 was shown by three isolates. Eight isolates produced ammonia, the value of which ranged from 1.3 to 6.1 μmol mL−1. All tested isolates were positive for siderophore production. For extracellular enzyme production, 7 isolates were positive for protease, 8 for cellulase and 10 for amylase production. The isolates were also tested for their antagonistic activity against R. solanacearum in vitro and in planta assay using tomato seedlings. Staphylococcus warneri GL1 showed the highest biocontrol efficacy of 77.67% followed by Bacillus velezensis GL3 i.e. 70.1%. R. solanacearum antagonistic isolates were analysed for the presence of antimicrobial peptide biosynthesis genes bmyB, srfAA, fenD and ituC. All the antagonistic isolates showed the presence of all four genes, except the isolate Bacillus velezensis GMC2, where the gene for fengycin synthetase (fenD) was absent. Based on in vitro PGP traits, three isolates Bacillus velezensis GL3, Bacillus atrophaeus GMC1 and Bacillus megaterium GS2 were selected, these three endophytic bacteria individually and their consortia were tested for in planta PGP activities in tomato plants. Application of Bacillus velezensis GL3 alone and consortia of three isolates showed significant improvement in growth parameters such as shoot length, fresh weight and dry weight in a pot experiment. Colonisation of endosphere of treated tomato seedlings by the endophytic isolate Bacillus velezensis GL3 was confirmed by visualisation of colony morphology and BOX-PCR fingerprinting. Our study highlights the potential of endophytes associated with unexplored plants like G. gnemon for development of bioformulation aimed at enhancing plant growth and bacterial wilt disease control.

Botany    Botany    https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Photo sensing zinc oxide porous silicon and ammonia sensing cadmium sulphide
Deepali Sarkar and her collaborators report about two works - one involving UV-visible photo sensing property of zinc oxide porous silicon and the other involving cadmium sulphide nanoparticle which can sense ammonia at room temperature. These works are published in the journals Materials Science in Semiconductor Processing and Sensors and Actuators A: Physical.



Authors
M Das, S Sarmah, D Barman, B K Sarma, and D Sarkar &
Ali Akbar, Mausumi Das, and D Sarkar

Abstract #1
Present article deals with fabrication of UV–Visible radiation sensing photodetector (PD) by architecting planar and sandwiched (PD1 and PD2) electrode configurations on ZnO-PS:p-Si heterostructure. PS:p-Si structure is prepared by electrochemical anodisation method. Thin ZnO layer of ~162 nm is deposited on PS:p-Si substrate using pulsed DC magnetron sputtering technique. Gold (Au) is combined with Aluminium (Al) to provide rectifying Schottky contacts to the devices. Prior to device testing, it is tested for various conventional characterisations. FESEM studies confirm uniform deposition of nanocrystalline ZnO thin film with mean particle size of ~ 35 nm, whereas its cross section shows uniform interface between ZnO and PS with combined thickness of ~700 nm. Cross sectional EDX analysis confirms diffusion of ZnO particles into PS layer. UV–visible absorption spectrum gives band gap of ZnO as ~3.3 eV. Reflectance measurement of the heterostructure shows decrease in reflectivity compared to bulk c-Si with ZnO-PS:p-Si showing multiple interference pattern compared to bare ZnO coated on glass within the spectral range 200 nm-800 nm. The pattern is remarkably increased compared to that of PS:p-Si. Photoluminescence study reveals various luminescence bands peaked at ~378 nm, 388 nm, 398 nm, 410 nm, 420 nm, 433 nm, 450 nm, 467 nm, 482 nm 492 nm and 597 nm. Current- Voltage (I–V) measurement for dark current (Id) gives low leakage current of the devices PD1 and PD2 respectively as 6.6 x 10−8 A and 7.5 x 10−7A at -5 V, which is however an order of magnitude more than the ZnO coated one on glass. Both the devices PD1 and PD2 show UV–Visible photoresponse, whereas the ZnO device on glass shows response to UV (375 nm) only. Both the devices show response time ~1 s in visible range which is nearly half the value in UV range.

Abstract #2
In this work, a chemical co-dispersion technique is employed to develop CdS decorated polyaniline (PANI) nanocomposite. The composite film is used to develop into room temperature ammonia (NH3) sensor. Prior to sensing study, the composite films are characterized to elucidate the structural, morphological and thermal properties. Structural and morphological studies reveal attachment of CdS nanoparticles on polyaniline nanorods. Gas sensing properties of PANI-CdS composite sensor is studied thoroughly and compared with bare PANI sensor. The room temperature gas response towards acetone, ammonia, methanol, formaldehyde and ethanol is investigated and found the sensor to be selective towards ammonia. The maximum gas response of 250% is achieved with 74% stability for the composite sensors upon exposure of 100 ppm of NH3 at room temperature. Response and recovery times show a decreasing trend with increasing concentration of NH3 gas.

Collecting a rare species of flora
Manash Baruah and collaborators collect an extremely rare plant after about 145 years from a region in the Golaghat district of the northeastern Indian state of Assam. Their findings are reported in the Journal of Threatened Taxa.


Authors
Debolina Dey, Manash Baruah, Nilakshee Devi, and Jitendra Nath Borah1
from another organisation

Abstract
The present work records the re-collection of an extremely rare plant Ceropegia lucida Wall. from the Golaghat District of Assam after a gap of 145 years. A detailed account of the plant has been given to aid in its proper identification and further conservation steps.

Journal Reference


https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Transparent conductors with aluminium-doped zinc oxide layers
Bimal Kumar Sarma and his graduate students prepare transparent conductors with Al-doped ZnO layers. Some of these conductors may find their places as potential candidates for next generation optoelectronic devices. These research works are published in the journals Materials Today Communications and Vacuum.


Authors
Bimal K Sarma and Pradhyut Rajkumar &
Dipak Barman and Bimal K Sarma

Abstract #1
The objective of this work is to provide high quality indium free transparent and conducting oxide film in which ZnO is the primary component and Al is the only dopant. A range of Al-doped ZnO (AZO) transparent conductors has been realised from the developed AZO sputtering targets with varying dopant concentrations with content of the dopant material Al2O3 added in the range 0.5–5.0 wt.%. X-ray diffraction, Raman spectroscopy, AFM measurements, and elemental analyses reveal promising material properties. The sheet resistance of 2.3 Ω/sq, visible light transmittance over 90%, and figure of merit of 75.9 mΩ–1 are the optimal electro-optical characteristics of AZO thin films. The resistivity of AZO films is dependent on the dopant concentrations with the lowest value estimated to be 1.66 × 10–4 Ω cm. A comparison of the figure of merit of AZO films with that of ITO suggests application potential of AZO as transparent conducting oxide. High transparency effect of AZO films in the near-UV spectral region is limited by the strong fundamental absorption. The hypsochromic shift of this onset of band-to-band absorption accentuates beyond 1.0 wt.% of Al2O3, which is primarily ascribed to the Moss-Burstein effect in this degenerate semiconductor. The bulk plasmon frequencies fall in the near infrared region where transmittance curves of AZO films completely differ from that of ZnO. A significantly high free carrier absorption in the near infrared suggests formation of free electron gas upon doping. With abundance of free electrons and low dielectric loss, AZO may serve as a promising infrared plasmonic material.

Abstract #2
In this work, an attempt has been made to develop thin and flexible transparent conductors based on the interfaces of Ag nanoparticles (AgNP) and Al:ZnO (AZO) deposited by sequential magnetron sputtering. The entire deposition process is completed within 20–28 min without breaking vacuum thereby preventing post-deposition oxidation of Ag NPs. The co-existence of high transmittance and low sheet resistance along with stability under mechanical bending is a bit difficult to achieve in bare AZO thin film having thickness below 200 nm. The resistivity of the optimised AZO/AgNP/AZO composite structure is significantly low at 3.3 × 10−5 Ω cm, which is two orders lower than that of AZO thin film of similar thickness. The figure of merit of the optimised composite structure peaks at 39.0 mΩ−1 corresponding to Ag NPs growth period of 5 min. The novel fabrication of AZO/AgNP interface in a dry and vacuum environment facilitates superior bending stability required for a flexible transparent conductor. The findings suggest that a system of two thin layers of AZO with embedded Ag NPs can be a potential candidate as an indium free transparent conductor for the next generation optoelectronic device.

Synthesis of magnetic nanocomposites
Debajyoti Mahanta and his collaborator report about synthesis of two magnetic nanocomposites, which may have possible use in wastewater treatment. This work is published in the Journal of Environmental Chemical Engineering.


Authors
Abstract
The fabrication and synthesis of easily separable novel materials with excellent adsorption capacities are still challenging in the field of wastewater treatment. This work illustrates the synthesis of magnetic Fe3O4 nanoparticles by a simple solvothermal method. This report further, demonstrates the surface modification of the Fe3O4 nanoparticles with polyaniline and polypyrrole. The, as prepared nanocomposites were systematically tested as adsorbents for 2, 4-dichlorophenoxyacetic acid in aqueous medium. The structural characteristics, thermal stability and morphology of the adsorbents were examined by FTIR spectroscopy, PXRD, TGA and SEM. The results obtained from kinetic study provided good fitting for pseudo-second-order model with R2 values close to unity; implying chemisorption mechanism. Further, three isotherm models namely, Langmuir, Freundlich and Temkin were used to study the adsorption mechanism. The maximum adsorption capacities of the adsorbents; Fe3O4-PANI and Fe3O4-PPy as obtained from Langmuir model at 303 K are 60.97 and 96.15 mg g−1 respectively. 1/n values as calculated from the Freundlich isotherm model are less than unity indicating heterogeneous multilayer adsorption. Positive ΔH° values (10.19 kJ mol−1 and 13.88 kJ mol−1) and negative values of ΔG° as obtained from thermodynamic calculations described the adsorption process to be endothermic and spontaneous. The adsorbents can be magnetically separated and regenerated with a negligible change in adsorption performance. The findings of this study reveal these magnetic nanocomposites to be quite promising as adsorbents for organic pollutants such as 2, 4-D in wastewater treatment.

https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Big Bang nucleosynthesis at LHC (CERN)
Buddhadeb Bhattacharjee and collaborators (through ALICE collaboration) study the collisions of Pb-Pb nuclei in the ALICE detector at LHC, CERN. The ALICE experiment creates an environment similar to the one created just after the Big Bang. This work is published in journal Physical Review C


Authors
S Acharya1 and 1097 other authors1 (B Bhattacharjee, N Hussain, G Volpe1, Y C Morales1, N Jacazio1, A O Velasquez1, I Ravasenga1, and  O V Rueda1)
from other institutions

Abstract
Midrapidity production of  π±, K± , and (p bar)p measured by the ALICE experiment at the CERN Large Hadron Collider, in Pb-Pb and inelastic pp collisions at √sNN = 5.02 TeV, is presented. The invariant yields are measured over a wide transverse momentum (pT) range from hundreds of MeV/c up to 20 GeV/c. The results in Pb-Pb collisions are presented as a function of the collision centrality, in the range 0 – 90% . The comparison of the pT -integrated particle ratios, i.e., proton-to-pion (p/π) and kaon-to-pion (K/π) ratios, with similar measurements in Pb-Pb collisions at √sNN = 2.76 TeV show no significant energy dependence. Blast-wave fits of the pT spectra indicate that in the most central collisions radial flow is slightly larger at 5.02 TeV with respect to 2.76 TeV. Particle ratios (p/π, K/π) as a function of pT show pronounced maxima at pT ≈ 3 GeV/c in central Pb-Pb collisions. At high pT, particle ratios at 5.02 TeV are similar to those measured in pp collisions at the same energy and in Pb-Pb collisions at √sNN = 2.76 TeV. Using the pp reference spectra measured at the same collision energy of 5.02 TeV, the nuclear modification factors for the different particle species are derived. Within uncertainties, the nuclear modification factor is particle species independent for high pT and compatible with measurements at √sNN = 2.76 TeV. The results are compared to state-of-the-art model calculations, which are found to describe the observed trends satisfactorily.

Journal Reference

https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Defence mechanism of legumes against herbivorous insects
Pratap Jyoti Handiquea and collaborators examine the defence mechanism of chickpea pod walls against herbivorous insects, using simulated herbivory. This work is published in the journal The Protein Journal.


Authors
Mamta Bhattacharjee1,2, Santanu Dhar1, Pratap Jyoti Handique, Sumita Acharjee1, and Bidyut Kumar Sarmah1
from other institutions

aProf PJ Handique is a Professor in the Department of Biotechnology of Gauhati University, who is also the Vice Chancellor of the university.

Abstract
The pod wall of legumes is known to protect the developing seeds from pests and pathogens. However, the mechanism of conferring defense against insects has not yet been deciphered. Here, the authiors have utilised 2-dimensional gel electrophoresis (2D-GE) coupled with mass spectrometry (MS/MS) to identify over expressed proteins in the pod wall of two different cultivars (commercial cultivar: JG 11 and tolerant cultivar: ICC 506-EB) of chickpea after 12 h of application of Helicoverpa armigera oral secretions (simulated herbivory). The assays were performed with a view that larvae are a voracious feeder and cause substantial damage to the pod within 12 h. A total of 600 reproducible protein spots were detected on gels, and the comparative analysis helped identify 35 (12 up-regulated, 23 down-regulated) and 20 (10 up-regulated, 10 down-regulated) differentially expressed proteins in JG 11 and ICC 506-EB, respectively. Functional classification of protein spots of each cultivar after MS/MS indicated that the differentially expressed proteins were associated with various metabolic activities. Also, stress-related proteins such as mannitol dehydrogenase (MADH), disease resistance-like protein-CSA1, serine/threonine kinase (D6PKL2), endoglucanase-19 etc. were up-regulated due to simulated herbivory. The proteins identified with a possible role in defence were further analysed using the STRING database to advance our knowledge on their interacting partners. It decoded the involvement of several reactive oxygen species (ROS) scavengers and other proteins involved in cell wall reinforcement. The biochemical analysis also confirmed the active role of ROS scavengers during simulated herbivory. Thus, the study provides valuable new insights on chickpea-H.armigera interactions at the protein level.

Journal Reference

Botany    Botany    https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Graphene quantum dots to sense moisture

Hemen Kalita and collaborators prepare graphene quantum dots which can be used as sensor for measurement of soil moisture. This work is published in the journal Carbon.


Authors
Hemen Kalita, Vinay S Palaparthy1, Maryam Shojaei Baghini1, and M Aslam1
from other institutions

Abstract
Graphene quantum dots (GQDs) the quantum dot variety of graphene represent a new group of quantum dots with exciting properties. Herein we report the electrochemical synthesis of GQDs with size ranging from 3 to 5 nm in diameter from graphene oxide (GO) at room temperature with LiClO4 in propylene carbonate as the electrolyte. The size of the GQDs can be tuned by playing with different parameters such as the applied potential, oxidation and reduction time, concentration of the supporting electrolyte. GQDs are promising candidate for humidity sensors, chemical sensors, nanoelectronic devices and biomarkers. In this paper, the potential use of the GQD as soil moisture sensors is also explored. We fabricated the micro-sensor where GQDs is used as the sensing material to perform the soil moisture measurements on two different soils. In our study, we observed that when soil water content varies from 0% to 32%, then sensor resistance changes by 99% and 97% for the red soil (silt loam) and black soil (clayey), respectively. We found that sensor response time was around 180 s for the both silt loam and clayey soils.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Economy of fishing activity at the Deepor Beel

Jyotisikha Dutta and Archana Sharma look at the economy of fishing activity at the Deepor Beel - one of the wetland biodiversity hotspot in the northeastern state of Assam. This work is published in the journal Space & Culture, India.


Authors
Abstract
The Deepor Beel is one of the large and important riverine wetlands in the Brahmaputra valley of Assam, India. The only Ramsar site of Assam, the Beel is one of the richest biodiversity grounds in the wetland eco-system of the state. The Deepor Beel is the hub of a wide range of organisms. It provides various goods and services directly or indirectly to the villages near to the beel for their livelihood. Despite its contribution to society and ecology as a whole, these goods and services of the Beel are undervalued in the policy provisions. The prime reason for this undervaluation is that most of the goods and services of the Beel are non-marketable and those goods which have direct use-values are never valued in an economic term. To fill the gap partially, this study tries to estimate the direct use values of the Deepor Beel. Among the goods the Deepor Beel provides, fishing can be considered one of the economically significant goods. Fishing provides livelihood directly to 825 households living near the Beel. Therefore, this research tries to estimate the direct use value of fishing in the Deepor Beel. A market price approach is applied to estimate the value of this wetland resource. Net Present Value (NPV) of fishing is also estimated. The total estimated value of fishing is INR 11,64,69,375 per annum. The estimated value of fishing per hectare is INR 29,015.78 per annum. The estimated Net Present Value (NPV) of fishing is INR 97,05,78,125. This valuation is important to draw the attention of the policymakers for resource investment in conserving the Beel for continued benefits.

https://sites.google.com/a/gauhati.ac.in/research/#top 
 



What's in a drink?

Hridip Kumar Sarma and his colleagues find out what that makes the indigenous drink that many people from Northeast India relish. This work is published in the Journal of the American Society of Brewing Chemists : The Science of Beer.


Authors
Bhaskar Jyoti Nath1, Ekta Verma3, Hridip Kumar Sarma1, Arun Kumar Mishra3, Bhaben Tanti2, and Dhruva Kumar Jha2

Abstract
In this study, yeasts inherent in traditional starter materials of four indigenous communities from northeast India were characterised. These included Saccharomyces and non-Saccharomyces types representing several genera and species such as Saccharomyces cerevisiae, Wickerhamomyces anomalus, Candida glabrata and Candida tropicalis. The yeasts were cultured in synthetic minimal media (2% glucose and 2% starch), both individually and in combinations. The propensity of growth of individual isolates in glucose appeared as W. anomalus > C. tropicalis > C. glabrata > S. cerevisiae. In starch, the propensity appeared as C. tropicalis > W. anomalus > C. glabrata > S. cerevisiae. The findings were incongruent when isolates were co-cultured in dual combinations in glucose and starch. In glucose, W. anomalus could not prosper with C. tropicalis, which otherwise was reversed in starch. C. tropicalis dominated all the co-cultures in starch followed by W. anomalus, S. cerevisiae and C. glabrata. In glucose, the order appeared as W. anomalus > C. tropicalis > S. cerevisiae > C. glabrata. S. cerevisiae could not thrive in competition with C. tropicalis and appeared dominant over C. glabrata in both glucose and starch. W. anomalus was dominant over S. cerevisiae and C. glabrata, while C. tropicalis outnumbered C. glabrata in both carbon sources. The fermentation efficiency was highest when S. cerevisiae and C. glabrata were co-cultured together, in both starch and glucose. This study suggests an advantage in co-culturing selective indigenous yeasts as consortia to yield a productive fermentation output that could have commercial benefit but additional strains of each species still needed to be investigated.

Journal Reference
Botany    Botany    Zoology    https://sites.google.com/a/gauhati.ac.in/research/#top 
 



A review of library metadata standards

Dipen Deka and his graduate student review how the library metadata standard has evolved over the centuries beginning from around 1840s. This work is published in the journal Library Hi Tech.


Authors
Abstract
The authors make a systematic review of the library metadata development history listing out the most significant landmarks and influencing events from Thomas Bodley's rules to the latest BIBFRAME architecture, comparing their significance and suitability in the modern-day Web environment. Four time divisions are identified, namely pre-1900 era, 1900–1950, post-1950 to pre-Web era and post-Web era based on pre-set information available to the authors regarding catalogue rules. Under these four divisions, relevant information sources regarding the purpose of the study were identified; various metadata standards released at different times were consulted. Findings Library catalogue standards have undergone transitive changes from one form to another primarily influenced by the changing work environment and different forms of resource availability in libraries. Modern-day metadata standards are influenced by the opportunities provided by the World Wide Web towards libraries and work as a suitable base for data organisation at par with Semantic Web standards. Research. Information organisation processes have gone towards a more data-centric approach than earlier document-centric nature in current Semantic Web environment. Libraries had to make a move in this process, and modern-day guidelines in this regard bring the possibility of large-scale discovery services through curated information resources. This study discovers the relationships between key events in the course of development of metadata standards and provides suggestions and predictions regarding its future developments.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Probing the galactic centre looking for a fifth force

Sanjeev Kalita explores the possibility of new gravitational physics with the Scalaron fifth force at the centre of our home galaxy - the Milky Way. This research work is published in the Astrophysical Journal.


Author
Abstract
The Galactic Centre black hole (Sgr A*) provides an ideal laboratory for astronomical tests of new gravitational physics. This work reports that curvature correction [f(R)] to quantum vacuum fluctuations naturally yields a Yukawa-type scalar fifth force with potential exp(-Mψr)/r, where Mψ is the mass of the f(R) scalarons. Estimating the UV and IR cutoff scales of vacuum fluctuations, the Yukawa coupling strength is connected to the scalaron field amplitude. Whereas recently constrained Yukawa coupling and range correspond to light scalarons with Mψ = 1.37 x 10−21 – 5.49 x 10−20 eV, vacuum fluctuations yield a massive scalaron with Mψ = 10−16 eV. Scalaron-induced periastron shift of stellar orbits near Sgr A* has been studied with respect to the semi-major axis in the range a = 10–1000 au. It is found that the scalarons resulting from quantum fluctuations affect the precession of orbits with a = 128–256 Rs . The possibility of future constraints on massive scalarons in observations near Sgr A* is discussed. This is a new and independent effort to express a prototype quantum gravity effect in terms of astronomically accessible quantities.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Dust dynamics over lunar surface

Madhurjya P Bora and graduate student Rinku Deka investigate dust dynamics above the lunar surface and show that dust clouds with striations may form within a few metres of the surface. This work is published in the journal Physics of Plasmas.


Authors
Abstract
The authors have presented a basic model for a one dimensional collisionless space charge limited (SCL) plasma sheath consisting of electrons, ions, and two kinds of dust populations - a nano-dust population and a micrometer sized dust population. They have assumed that the nano-dust particles, plasma electrons, photoelectrons, and ions are the constituents of the plasma fluid and the micrometer sized dust particles behave as suspended impurities in the plasma without affecting the plasma dynamics. They have assumed that the charges of the micrometer-dusts are determined from the current balance on them and the charges on the nano-dusts are fixed. Due to photoemission, like the lunar surface charges to a positive potential, so the nano-dust and micrometer-dust particles charge to a positive potential. The electron densities have been derived by assuming both the electrons and photoelectrons to be Maxwellian, whereas the ion and nano-dust densities are derived from energy conservation of the ions and nano-dust particles and the continuity equations. Being a constituent of plasma, the nano-dusts do affect the sheath dynamics through the Poisson equation, which determines the plasma potential in the sheath region. The typical conditions for the levitation of dust particles in an SCL sheath including the maximum height and maximum size of the particles are calculated.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Filtering dye pollutants with a graphene paper

Hemen Kumar Kalita and collaborators demonstrate how to remove dye pollutants from aqueous solution with the help of a surface tailored graphene paper. This work is published in the journal EnvironmentalScience: Water Research & Technology.


Authors
Hemen Kalita, Himanshu Tyagi1 and M Aslam1
from other institution

Abstract
The potential application of graphene as a filter paper for selectively removing cationic and anionic dyes from aqueous solutions is demonstrated herein. A surface-tailored graphene paper was fabricated by the vacuum filtration technique on a microporous substrate to remove two different classes of dyes. A negatively charged graphene paper was fabricated from graphene oxide (GO) solution, and a positively charged graphene paper was fabricated from polyallylamine-functionalised GO solution. The solutions of methylene blue (MB) and methyl orange (MO) were filtered through the negatively charged graphene paper (GO−) and positively charged graphene paper (GO+). The stacking structure of the GO− and GO+ paper successfully removed the MB and MO mixtures from the solution. The GO− and GO+ paper demonstrated a high retention rate of 99.8% for MB dye and 99.5% for MO dye. The pore size of the paper was found to be less than 7 nm, providing more insights into the rejection mechanism. The rejection mechanism involves the adsorption and electrostatic interaction (i.e. cationic–anionic interaction) between the dye and graphene sheets, which result in the fast and efficient removal of the dye. The GO paper displayed adsorption capacities as high as 311 and 340 mg g−1 for MB and MO dyes, respectively. The results indicate that the surface-tailored graphene paper is a great alternative for the next generation cost-effective filters in practical water purification applications.

A single-step process to synthesise free standing polypyrrole films

Debajyoti Mahanta and co-workers prepare a free standing polypyrrole film through a single-step process for the removal of anionic pollutants. This work is published in the journal Colloids and Surfaces A: Physicochemical and Engineering Aspects.


Authors
Sibani Majumdar, Rimjhim Moral, and Debajyoti Mahanta

Abstract
Polypyrrole has been synthesised by rapid mixing of the monomer and ferric chloride (FeCl3) solutions. By this method, free standing polypyrrole films at the air/water interface along with bulk polypyrrole powder (R-PPy) are formed as a result of a single step reaction. We have reported the characterisation of R-PPy and its application for removal of anionic pollutants such as Eosin yellow, Eosin blue, Orange (II), Reactive orange, Orange G and Cr(VI) from aqueous medium. The materials synthesised were characterised by Scanning electron micro- scopy (SEM), Zeta potential measurement, Powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) spectroscopy and Thermal gravimetric analysis (TGA). R-PPy shows an enhanced adsorption capacity compared to the polypyrrole (PPy) samples synthesised by conventional chemical polymerisation method. The percentage removal of EY increases from 58.8 % for PPy to 95.3 % in R-PPy and for Cr (VI) removal, it is 40.2 % for PPy which increases up to 69.5 % on using R-PPy for a definite initial concentration of the pollutants. The reduced agglomeration due to the synthetic procedure and a more positive surface charge density on the R-PPy particles are the reason for improved adsorption capacity of R-PPy than that of conventionally synthesised PPy. The authors have studied the effect of initial concentration, adsorbent dose, solution pH and temperature on the adsorption capacity. The adsorption was found to follow pseudo second order kinetic model. The Langmuir adsorption capacity of R-PPy was found to be 273.2 and 103.6 mg/g for EY and Cr (VI), respectively at 303 K. The thermodynamic parameters revealed that the adsorption is endothermic and spontaneous.

https://sites.google.com/a/gauhati.ac.in/research/#top 
 



A new fish species - Psilorhynchus kamengensis

Dandadhar Sarma and co-workers report about a new fish species from a stream of Kameng river, a northern tributary of the Brahmaputra drainage system in the northeastern state of Arunachal Pradesh, India. This work is published in the Vertebrate Zoology. They have reported another new species of the same genus, a few weeks ago (see the Highlight, immediately below).


Authors
Abhinit Dey, Hrishikesh Choudhury, Abhishek Mazumdar, Ratul Ch Bharali1, Sarbojit Thaosen1, and Dandadhar Sarma
from other institutions

Abstract
Psilorhynchus kamengensis, new species, is described from a stream of the Kameng River, a northern tributary to the Brahmaputra drainage, Arunachal Pradesh, northeast India. The new species belongs to the P. balitora species group and can be distinguished from all other members of this group by the presence of a longer post-epiphyseal fontanelle, 3 unbranched anal-fin rays, 9 + 8 caudal-fin rays, 35 vertebrae and fin coloration. The validity of the species is also corroborated by molecular phylogenetic analysis based on the mitochondrial cyt b gene.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



A new fish species - Psilorhynchus nahlongthai

Dandadhar Sarma and co-workers report about a new psilorhynchid fish from Diyung river, a tributary of Kopili river in the northeastern state of Assam, India. This work is published in the Journal of Fish Biology.


Authors
Abhinit Dey, Hrishikesh Choudhury, Sarbojit Thaosen1, and Dandadhar Sarma
from other institution

Abstract
Psilorhynchus nahlongthai, a new psilorhynchid fish, is described from the Diyung River, a tributary to the Kopili River (itself a southern tributary of the Brahmaputra drainage) in Assam, northeast India. It is placed in the Psilorhynchus balitora species group and can be easily distinguished from all other members of this group by a com- bination of the following characters: dense and prominent tuberculation on the head region; thick and long pre- and post-epiphyseal fontanelles on the neurocranium; 9 +8 caudal-fin rays; and 34 (24+10) vertebrae. Genetic divergence between P. nahlongthai and members of the P. balitora species group from the Brahmaputra and neighbouring drainages, with K2P distances ranging 3.7%–14.7% and 7.4%– 20.7% in the mitochondrial COI and cyt b gene datasets respectively, support its report as a new species.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Essential oils as ovicidal agents for Aedes aegypti (Diptera: Culicidae)

Bulbuli Khanikor and co-workers study the twenty essential plant oils (EO) as potential ovicidal agents for the mosquito species which can spread diseases like dengue fever, chikungunya, Zika, and several others. This work is published in the journal National Academy Science Letters.


Authors
Riju Sarma, Kamal Adhikari, Sudarshana Mahanta, and Bulbuli Khanikor

Abstract
In the present investigation, twenty plant essential oils (EOs) are tested against Aedes aegypti at their egg stage aiming to control the mosquito population at its breeding site. The results are very much promising for EOs extracted from Allium sativum, Mentha piperita and Ocimum sanctum with sublethal concentration (LC50) of 1.00 ppm, 4.01 ppm and 8.40 ppm, respectively, which seems to be at par with WHO-recommended dose for synthetic larvicide temephos. Three plant oils responded with LC50 below 50 ppm. However, few plant oils did not show lethal effects at all. The effective EOs can in future be used in breeding sites including the potable and household water tank as these plants are edible and hence safe for consumption. These might be a potent candidate for decreasing Aedes population and for replacing synthetic insecticides against Aedes. Moreover, these three highly effective EOs would be accessible and cost-effective for common people to use.

Journal Reference
Botany    Zoology    https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Antibacterial activity of Spotted Gum (Eucalyptus maculata Hook.) against fish pathogens

Dandadhar Sarma and co-workers investigate the antibacterial properties of leaf essential oil of Sotted Gum against two fish pathogens. This work is published in Journal of Essential Oil Bearing Plants.


Authors
Abhishek Mazumder, Hrishikesh Choudhury, Abhinit Dey, and Dandadhar Sarma

Abstract
The present study was intended to evaluate the antibacterial activity of leaf essential oil (EO) of E. maculata and its major compound, identified from the crude EO against Aeromonas hydrophila and A. jandaei. The major compound was found to be 1,8-cineole through Gas Chromatography-Mass Spectrophotometry-Flame Ionisation Detector analysis. Both EO and 1,8-cineole showed potential antibacterial activity against the tested microorganisms. Sensitivity of A. hydrophila to both crude EO and its major compound was found to be relatively higher, in comparison to A. jandaei. The positive results indicate their efficiency as a natural anti-bacterial agent for the treatment of several pathogenic diseases caused by these two microorganisms, and understanding the relations between traditional cures and current medicines.

Botany    Zoology    https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Detection of binary stars in King 1 open cluster

Eeshankur Saikia and collaborators report the detection of binary stars in the open cluster field King 1. This work is published in the journal Research in Astronomy and Astrophysics.


Authors
Parvej Reja Saleh, Debasish Hazarika, Ajaz Ahmad Dar1, Padmakar Singh Parihar1, and Eeshankur Saikia
from other institutions

Abstract
A rarely studied open cluster, King 1 is observed using the 1.3-m telescope equipped with a 2k x 4k CCD at Vainu Bappu Observatory, India. We analyze the photometric data obtained from CCD observations in both B and V bands. Out of 132 detected stars in the open cluster King 1 field, we have identified four stellar variables, and two among them are reported as newly detected binary systems. The parallax values from Gaia DR2 suggest that the open cluster King 1 is in the background of these two detected binary systems, falling along the same line of sight, giving rise to different parallax values. Periodogram analysis was carried out using Phase Dispersion Minimization (PDM) and the Lomb-Scargle (LS) method for all the detected variables. PHysics Of Eclipsing BinariEs (PHOEBE) is extensively employed to model various stellar parameters of both the detected binary systems. Based on the modeling results obtained from this work, one of the binary systems is reported for the first time as an Eclipsing Detached (ED) and the other as an Eclipsing Contact (EC) binary of W-type W UMa.

https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Antibacterial properties of flower-shaped ZnO (FZnO) microstructures

Eeshankur Saikia and collaborators study antibacterial properties of flower-shaped ZnO microstructures using nonlinear dynamics tools. This research work is reported in Scientific Reports.


Authors
Abstract
The present study reports the antibacterial properties of flower-shaped ZnO (FZnO) microstructures and its comparison with that of hexagon-shaped bulk ZnO (BZnO) nanostructures. The samples are prepared successfully by wet chemical method and the surface morphologies, structures and size of the ZnO samples are characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), BET adsorption isotherm, and Photoluminescence (PL) Spectroscopy. The SEM and TEM images of the sample have confirmed flower-shaped structure of the ZnO. The materials are also analyzed by using an innovative tool called Lacunarity, a nonlinear dynamical (NLD) tool for proper understanding of the inherent surface properties of the particles formed, comparing the results estimated with the BET results obtained, thereby confirming our proposition to use it as an important parameter in predictive models. In this new approach, geometry of the surface structure is being associated with biological properties, in order to come up with easier ways to identify materials for any such applications where rich surface structure is desired. The photocatalytic activity of the flower-shaped material is carried out to find out its optical properties as another marker for confirming the antimicrobial activities. It has been reported for the first time that the prominent antibacterial activities are favoured by the FZnO microstructure having lesser Lacunarity, significantly better than its bulk counterpart, for inhibiting gram negative - Escherichia coli microorganism.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Electrical and optical properties of fullerene

Sankar M Borah and his colleagues study electrical and nonlinear optical properties of fullerene through density functional theory (DFT). Fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms. This work is published in the journal Applied Physics A.


Authors
Samir Thakur, Sankar M Borah, Ashok Singh1, and Nirab C Adhikary1
from other institutions

Abstract
The authors used density functional theory (DFT) to investigate the structural, electronic and nonlinear optical properties of N, P, As and Sb doped fullerene. The average polarizability and hyperpolarizability is significantly improved when these impurities are substituted individually in the (C60) lattice structure. The maximum hyperpolarizability is calculated for N-doped fullerene (3541.27 au) followed by P-doped fullerene (259.71 au), As-doped fullerene (102.52 au) and Sb-doped fullerene (32.06 au). A similar trend is observed and the polarizability is found to decrease monotonically. Both the polarizability and hyperpolarizability values are found to decrease with an increasing energy gap of the doped fullerene. N-Doped fullerene has the lowest energy gap (1.28 eV) followed by P-doped fullerene (1.94 eV), As-doped fullerene (2.02 eV) and Sb-doped fullerene (2.10 eV). The lowest energy gap minimizes the excitation energy and thus improves the nonlinear optical response. From the calculation of time-dependent-DFT (TD-DFT), it is observed that the maximum absorption wavelength of N-doped fullerene, which is about 830 nm, is shifted towards the longer wavelength at the infrared region in the case of P, As, and Sb-doped fullerenes. The results obtained through this study will help encourage the potential utilization of the metal-free doped-fullerene systems as a form of unique optical devices, thermal radiation detector, etc.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Smartphone to measure chlorophyll contents

Ridip Dev Choudhury and his collaborator show how to measure the chlorophyll content with a smartphone, which may be a potential quick cost-effective way. This research work is published in the Journal of King Saud University - Computer and Information Sciences (Elsevier).


Authors
Abstract
The chlorophyll of leaf can be determined using soil plant analysis development meter or spectrophometer by agriculture scientists, agriculture experts, and farmers. Usually, these methods are very costly and may not be available to all the farmers and experts. Low greenness of leaf indicates low photosynthesis in the plant and it creates many problems in the plant. This paper forwards a low-cost smartphone image-based digital chlorophyll meter to predict the chlorophyll of citrus leaf. The chlorophyll of citrus leaf is predicted using Linear Regression (LR) and Artificial Neural Network (ANN). Here, ANN provides more accuracy as compared to LR in citrus chlorophyll prediction. Both methods are validated with the actual chlorophyll of the citrus leaf. The proposed method can be used as a reasonable method for chlorophyll prediction of citrus.

https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Erosion study of Subansiri river

Dhrubajyoti Saharia and coworkers carry out a riverbank erosion study of the Subansiri river, located in Assam (India). Their study reveals some interesting facts about this river of this flood-prone state. This work is published in the journal Applied Geomatics.


Authors
Kusumbor Bordoloi1,2,Bhaskar Ramachandra Nikam1, S K Srivastav1, and Dhrubajyoti Sahariah
from other institution  2 also from other Department of Geography, GU

Abstract
Riverbank erosion is one of the key geomorphological problems encountered in the floodplains of the alluvial rivers. Many recent studies on fluvial dynamics have indicated advantages of geospatial technology over traditional techniques in terms of time, cost, and practical usability by the end-users. This study aims to assess the riverbank erosion and erosion probability in a highly dynamic and unstable stretch of the Subansiri River in Assam (India) using geospatial approach along with the Graf’s model. Temporal Landsat datasets for a period of 29 years (1989 to 2017) in time step of 4–5 years are used for mapping the river channels (active floodplains) of the Subansiri River. These river channel datasets were then analyzed to spatially quantify the erosion/aggradation and identify the high riverbank erosion zones. Identification and analysis of the high riverbank erosion zones revealed a general westward shift of the Subansiri River during the studied period. The Graf’s model, used for estimating the riverbank erosion probability, is implemented in geographical information system (GIS). The transition probability matrices for riverbank erosion were generated for different time spans (1989–1994, 1994–1998, 1998–2002, 2002–2006, 2006–2010, and 2010–2014) using the distance to river channel and erosion/aggradation maps prepared using remote sensing data. Flood recurrence intervals of the annual floods from 1988 to 2017 were estimated using observed discharge data. The transition matrices and flood recurrence intervals were then used to calibrate the Graf’s model for estimating the probability of riverbank erosion of the Subansiri River. The results were validated with observed erosion/aggradation map of 2014–2017 time period. The study demonstrates the strength of geospatial approach for rapid assessment of riverbank erosion of alluvial channels. The calibrated Graf’s model developed in this study along with understanding of the migration behavior of the Subansiri River will be useful for taking mitigation measures and planning river management strategies.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Classification of a new plant species - Impatiens pseudolongipes

Souravjyoti Borah and collaborators report the classification of a new plant species Impatiens pseudolongipes and describe the taxonomic identity of the species Impatiens longipes. This work is reported in the journal Phytotaxa.


Authors
Rajib Gogoi1 , Norbu Sherpa1, and Souravjyoti Borah
from other institution

Abstract
The taxonomic identity of the species Impatiens longipes Hook.f. & Thomson is discussed and a lectotype has been designated for the name. Impatiens pseudolongipes is described and illustrated as a new species.

Impatiens species flowers are complete, bisexual with functional male (androecium) and female (gynoecium) reproductive units, including stamens, carpels and ovary.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Mechanochemistry of drug-drug and drug-nutraceutical multicomponent solids

Ranjit Thakuria and collaborators report about preparation of drug-drug and drug-nutraceutical multicomponent solids using mechanochemistry. Mechanochemistry or mechanical chemistry is the coupling of mechanical and chemical phenomena on a molecular scale. This research work is published in the journal CrysEngComm.


Authors
Kashyap Kumar Sarmah, Nilamoni Nath, Dharmaraj R Rao1, and Ranjit Thakuria
from other institution

Abstract
Drug–drug and drug–nutraceutical multicomponent solids of an antipsychotic drug olanzapine (OLN) are prepared using mechanochemistry. Drug molecules, viz., nateglinide (NAT) and pyrazinoic acid (PZO) as well as nutraceuticals, namely, 2,4,6-trihydroxybenzoic acid (246THBA), gallic acid (GA) and sinapic acid (SPA) are used as coformers in this study. After neat grinding (NG), incomplete conversion (partially amorphous) was observed, whereas liquid-assisted grinding (LAG) resulted in the formation of coamorphous OLN–NAT and crystalline salts/salt hydrates of OLN with rest of the coformers, which were characterized using a combination of techniques, including single crystal X-ray diffraction. The OLN–NAT coamorphous salt has a potential scope for development as a combination drug in order to suppress the increase in the blood sugar level, a common side-effect observed during the monotherapy of psychiatric patients using OLN. The equilibrium solubility study shows a substantial enhancement in the solubility of olanzapinium pyrazinoate compared to that of the pure base.

Journal Reference
https://sites.google.com/a/gauhati.ac.in/research/#top 
 



Fractal nature of nanoparticles

Eeshankur Saikia and co-workers have reported multifractal nature in ZnO nanoparticles. This work is published in the journal Material Science and Engineering C.


Authors
Rajat K Saha, Mrinal K Debanath, and Eeshankur Saikia

Abstract
ZnO nanoparticles (NPs) have variety of applications in different fields due to its size, structure, as well as physical and chemical properties. One of its prominent characteristics is its antibacterial behaviour. Nonlinear Dynamical Theory (NLD) has a vast scope in the field of material science, especially when subtle correlations are searched for to extract hidden information. Since nano-ZnO materials may be used in inhibiting pathogens, its nonlinear features can be quantified and calibrated with the help of NLD tools. Multi-fractal Analysis (MFA) is an important diagnostic tool of NLD for not only analysing nonlinear signal or images, but also predicting any spurious events likely to occur in the system under study. Thus, the analysis of the surface texture of the ZnO nano particles formed, using the TEM images and relate it with the variations of the XRD signal using NLD tools, is our first attempt reported here. Further, tools of MFA are used, for the first time, to see if there exists any correlation between the texture of the nano particles formed and the Zone of Inhibition (ZoI) we obtain as an output after allowing certain pathogens inhibit in the presence of the same nano particles. Analysis of TEM images guide us to predict the texture and structure of crystallites of ZnO:Cu samples which are responsible for overall behaviour of inhibiting pathogens. In this paper, MFA of ZoI images, TEM images, and signal of four different Cu-doped ZnO nanoparticles are carried out and their outcomes are calibrated for estimating the size and pattern of unknown NPs synthesised under similar physical and chemical condition. Moreover, that MFA can be used reliably to predict spurious or abnormal surface structure or bacterial inhibition is also established.

https://sites.google.com/a/gauhati.ac.in/research/#top