University of Burdwan
  • Barddhamān, India
Recent publications
This manuscript presents the suitability of the compact, low-cost, dual frequency GNSS modules (CLD) for GNSS precise points positioning (PPP) by comparing the results with simultaneously operating costly geodetic receivers using two CLD modules and two geodetic receivers. Online PPP is done from NRCan, Canada, using the rapid, ultra-rapid, and final IGS products. The results show the similar performance of all the hardware with the clear advantage of cost, size, and power requirements in case of the CLD modules; 3 mm × 3 mm × 10 mm PPP position uncertainty with 95% confidence is achieved in latitude, longitude, and altitude respectively for an uBlox ZED F9P CLD module and similar performance for an NTLab 104v3 CLD module in GPS + GLONASS hybrid operation like the geodetic receivers. It is also observed that the GPS + GLONASS hybrid operation provides better performance than single-constellation operations, and the use of final IGS products marginally improves the solution quality. The results would be useful in implementing cost and power-efficient, precise GNSS PPP for relevant applications.
Improving the balance between exploration and exploitation stages is very crucial for preventing local optima when using metaheuristic algorithms to solve optimization problems. This is made by a number of procedures, including hybridization and search agent improvement. This work deals with the modelling of single deteriorating item based two-warehouse inventory system with variable demand depending on time, frequency of advertisement and displayed inventory level. Customers’ waiting time dependent partially backlogged shortages are allowed. Moreover, price break facilities are available for the retailer. In the proposed model, transportation costs for replenishing the items as well as for transferring the item from rented warehouse to owned warehouse are considered. Based on displayed inventory level and capacity of owned warehouse, different cases are investigated and the corresponding optimization problems are developed. An extended version of hybrid Tournament Differential Algorithm (TDE) is applied to solve the said optimization problem. Then the same problem is solved by differential evolution and teaching learning based optimization algorithm and the obtained results are compared with TDE algorithm. Finally, a numerical example along with sensitivity analysis (graphically) is carried out to illustrate the proposed model and also to explore how the changes in key model parameters effect on optimal policy. To analyze the statistical interpretation of different metaheuristic algorithms, a non-parametric test is performed.
Using a Volume-Bragg-Grating at the signal wavelength in a periodically-poled LiNbO3 non-resonant optical parametric oscillator we achieve a total average power of 11.35 W at 20 kHz corresponding to a conversion efficiency of 63%. The measured signal and idler bandwidths amount to 0.7 and 0.9 nm at ∼1922 and ∼2384 nm, respectively. The spectral features are well reproduced by numerical modeling in the plane-wave approximation taking into account pump depletion and back conversion.
Wetlands play a crucial role in mitigating climate change via the process of carbon sequestration (CS). The spatiotemporal evaluation of methane (CH4) emission, and CS throughout the pre-monsoon, monsoon, and post-monsoon seasons was carried out in the Purbasthali wetland, an oxbow lake, situated in the Purba Burdwan region of West Bengal, India. Standard process-based mathematical equations were applied to compute the net CS. Various soil and water variables were also observed spatiotemporally and a machine learning-based artificial neural network (ANN) model was employed to find out the major factor influencing CS. Moreover, the net CS along with water quality index (WQI) was used to assess the ecological restoration in this lake. The study showed that emission was higher in the monsoon months (1083.59 ± 56.54 gCO2e m⁻² yr⁻¹), whereas CS was higher (2411.88 ± 72.26 gCO2e m⁻² yr⁻¹) in the post-monsoon season. The average total net CS in the Purbasthali throughout the study was 13.96 ± 8.35 tCO2e ha⁻¹ yr⁻¹. The ANN model revealed that dissolved oxygen (DO) and temperature are most important features that influence net CS. These findings can be utilized to develop an effective monitoring system aimed at optimizing CS rates, reducing CH4 emissions, and identifying ecological imbalances. The observed variations in net CS and WQI for the Purbasthali wetland are linked to shifts in wetland usage patterns and the seasonal enhancement of ecosystem services. Notably, the positive net CS indicates improved environmental conditions within the lake and its surroundings, reflecting the success of restoration efforts undertaken by the local community and government. On a global scale, restored and constructed wetlands have proven to be highly effective in carbon storage, pollutant removal, and habitat improvement, contributing significantly to climate goals and urban sustainability objectives. The work was inclined to meet the Sustainable Development Goal 14.
This paper is devoted to the study of gradient ρ\rho -Einstein soliton. We have derived volume growth estimate for non-trivial gradient shrinking ρ\rho -Einstein soliton with non-negative scalar curvature. Later, an isometry theorem is obtained for non-trivial compact gradient ρ\rho -Einstein soliton with a restriction on ρ\rho . Further, it is showed under certain hypotheses that a compact gradient ρ\rho -Einstein soliton is trivial. Finally, we established that the potential function in a compact gradient ρ\rho -Einstein soliton is affine.
This tutorial min review discusses the important features of nanotechnology of colour generation by the quantum dots (QDs), nanostructured photonic crystals (PCs) and plasmonic metal nanoparticles. Quantum dots (QDs) are characterized by the tunable and size dependent strong fluorescence emission properties. Photonic crystals (PCs) generate the material independent structural colour ( iridescent colour dependent on the angle of observation ) due to the constructive interference arising from Bragg diffraction by the nanostructured photonic crystals (PCs) producing the diffraction gratings. It causes the vibrant colour in the opals and pearls, wings of peacocks and butterflies, in the necks of pigeons, variable colours in chameleons, etc. Plasmonic nanoparticles like Au-, Ag- and Cu-nanoparticles show the both light absorption and scattering properties that can be tuned by varying the size, morphology and composition of the nanoparticles. Structural colour ( iridescent colour ) by PCs is used by nature while colouring by QDs and plasmonic nanoparticles are due to the man made activities. The nanotechnology based colour is superior to the organic pigment based colour in terms of brightness and photostability and this field is an emerging area of research with a great promise in terms of applications in various fields.
Colors observed are due to various reasons: absorption, emission, reflection, refraction, black body radiation (incandescence), scattering, and nanotechnology (tunable fluorescence emission by the semiconductor quantum dots, iridescent color due to Bragg’s diffraction by the photonic crystals, surface plasmon resonance of the plasmonic nanoparticles). These various reasons for the observed color are not illustrated and discussed in a single source, and the nanotechnology-based color is unknown to most undergraduate students. The tutorial review in two parts (parts 1 and 2) summarizes and explains all these with suitable examples. Part I of this series discussed phenomena like absorption, emission, reflection, and refraction, with examples to explain the reasons behind the observed color in many cases. In part II, we will discuss other phenomena like black body radiation, scattering, and nanotechnology of color.
Background and aims Microbial-driven dissimilatory nitrate reduction to ammonium (DNRA) is a unique pathway in the terrestrial nitrogen (N) cycle. It helps to retain N within the soil, preventing its loss to the surrounding environment. Due to the frequent flooding and draining, rice ecosystems experience both aerobic and anaerobic conditions, causing a shift in microbial process. Our goal in the present study was to understand the influence of various environmental factors and their regulatory mechanisms of DNRA pathway and also assess the nrfA gene-targeted (marker functional gene of DNRA) microbial community under diverse upland and lowland rice agro-ecosystems in sub-humid tropical condition. Methods Investigated rice agro-ecosystems for the present study were i) irrigated (IR), ii) three lowland, based on water depth i.e., shallow lowland: 0–30 cm; intermediate lowland: 30–50 cm; semi-deep lowland: 50–100 cm, and iii) two upland (dry or rainfed and aerobic) conditions. Soil physico-chemical and extracellular enzymatic activities, microbial dynamics and metabolism, nrfA-gene targeted metagenome, and both absolute and expressional quantification of nrfA-gene were performed and analysed under these diverse rice agro-ecosystems. Results Our findings showed that the DNRA activity was significantly (p < 0.05) correlated with the C/N ratio in arable paddy soil, which suggested that DNRA activity might be possible in diverse rice agro-ecosystems apart of anoxic reducing conditions. Biolog ecoplate-based study revealed that among different carbon guilds, amino acids utilising microbial community was more in semi-deep lowland compared to other rice agro-ecosystems. Interestingly, a higher (~ 20.44%) abundance of nrfA gene (7.01 log copy number g⁻¹ soil) was found in semi-deep lowland compared to upland dry conditions. Similarly, the functional expression of nrfA transcripts copy number was found higher in semi-deep lowland, possibly due to the presence of predominant taxa belonged to class Deinococci and Anaerolineae. Conclusion Higher abundance of DNRA microbial communities such as Actinomyces radicidentis, Geobacter uraniireducens, Thermogutta terrifontis in lowland rice, and Anaeromyxobacter dehalogenase, and Anaeromyxobacter sp. Fw109-5 in upland rice conditions could suggest the adaptability and functionality of these microbial communities in response to diverse rice agro-ecosystems. Moreover, environmental conditions in paddy soils might be crucial for driving the DNRA pathway, and it is necessary to examine this adaptation from the perspective of microbial genome mining in order to clarify the ecological significance of DNRA in rice agro-ecosystems. Graphical abstract The schematic representation showed the terrestrial nitrogen cycle and mainly focused on dissimilatory nitrate reduction to ammonium (DNRA) pathway under i) irrigated (IR), ii) three lowland based on water depth i.e., shallow (SL): 0-30 cm; intermediate (IL): 30-50 cm; semi-deep (SD): 50-100 cm, and iii) two upland (dry or rainfed: DR and aerobic: AR) rice agro-ecosystems. This study quantified the functional gene abundance and expression of the DNRA process i.e., nrfA gene, under diverse rice agro-ecosystems. The nrfA-targeted bacterial community through the metagenome identified keystone DNRA bacterial taxa, the role of various edaphic factors, and their influence on the DNRA pathway under different upland and lowland sub-tropical rice agro-ecosystems.
Election provides an important opportunity to advance democratization and encourage political liberalization. Free and fair election is the foundation of every healthy democracy. But to have confidence, voters need to be assured that their elections are truly free, fair and secure. Now it is very essential to introduce recent technologies to conduct fair and smooth election. In this article we have introduced a thumb impression based vote casting method and geoencryption based intelligent cryptosystem that provides the security in EVMs and poll data of election. Our aim is to protect the unauthorized access of confidential poll data based on the coordinate system and cryptographic algorithm. GPS is the backbone of our voting system. Vote counting personnel must be present at a particular coordinate to properly decrypt the polling information. Geoencryption key is generated based on longitude and latitude of two particular coordinates. There are three modules in our cryptosystem—location and hybrid intelligence based key generation, symmetric key based authentication and double encryption. The different types of experiments and their results and analysis conforms that our technique is very efficient for location based data security.
GNSS receivers provide direct and easy access to the UTC through its hardware 1PPS output. Despite the widespread use of geodetic GNSS receivers, more studies are needed on their timing performance. A campaign mode exercise was conducted with a geodetic GNSS receiver in GPS-only mode to address this gap. The experiment was performed in two modes- without and with an external standard frequency fed to the receiver to study its impact on the performance. The impact of a stable oscillator has been observed by the appreciable improvement in frequency stability of the GNSS time with respect to UTC(NLPI). Though notable improvement in standard deviation is observed with the external reference frequency, the performance in the other mode was within a limit of 10 ns; such results are not reported earlier. Further, this paper proposes a novel method of evaluating the delay of the hardware 1PPS during its derivation from the internal time solution from the measured pseudo ranges. The delay is 30.6 ns for this receiver, though depending on its internal circuit arrangement, it may vary across receivers. Understanding this delay would be crucial for specific timing applications. The importance of finding the delay is explained through a notional application.
A comprehensive study was conducted on the life history parameters of an important vector Culicoides oxystoma Kieffer (Diptera: Ceratopogonidae), to standardize potential rearing procedures. Data on life history traits and rearing conditions are crucial for establishing laboratory colony and conducting vector competence-based studies utilizing specimens with a known rearing history. Six different substrate compositions were used to rear the larvae: S1: habitat mud containing cattle manure + nutrient broth + yeast, S2: yeast, S3: habitat mud containing cattle manure + nutrient broth, S4: nutrient broth, S5: sterile (habitat mud consisting cattle manure + nutrient broth + yeast) and S6: tap water. Gravid females preferred ovipositing on beds moistened with tap water compared to distilled water. Egg hatching recorded minimal (3%) in the sterile substrate (S5), hinting at the role of live microbial load. Progression of larval instars got disrupted at 1st instars in S5 and S6. Larval survival and adult emergence were the highest in S1 and the lowest in S4, indicating that S1 is highly effective in the rearing of this species. The life cycle parameters and duration between transitional stages were evaluated at 15 °C, 20 °C, 26 °C, 30 °C, and 35 °C using rearing substrate S1. The highest larval survival (>70%) and adult emergence (69%) were achieved at 26 °C. The duration from egg to adult was 16 to 20 d at 35 °C, 18 to 24 d at 26 °C, but up to 36 d at 15 °C. Elucidating the effective rearing conditionalities of this important vector species will be helpful to study the transmission cycles of pathogens.
Culicoides oxystoma Kieffer (Diptera: Ceratopogonidae) transmits many pathogens, including seven viruses, four protozoa and one nematode. This species has a wide distribution range across northern Afro-tropical, Palearctic, Australian, Indo-Malayan realms with a broad host spectrum, including cattle, buffaloes, sheep, pigs, dogs, horses and even humans. The heterogeneous nature of Culicoides' blood-feeding patterns is well documented, but the influence of various host blood meal sources on gut bacterial composition remains scant. Adult midges were collected during April (2023) by operating UV light traps in cattle, buffalo sheds and poultry farm in Purulia (India). Besides C. oxystoma, eleven Culicoides species were collected across the sheds and farm, seven of which are vectors. Culicoides liui Wirth and Hubert and C. thurmanae Wirth and Hubert are reported from India for the first time. In all the sheds, engorged females of C. oxystoma were ubiquitous. Identification of culturable gut bacteria and the host blood meal of C. oxystoma were done through the polymerase chain reaction (PCR)-based method. Blood meal analysis confirmed the following hosts: cattle, buffaloes and humans. Identification of blood meal of engorged C. oxystoma caught from poultry farm showed positive results for humans but not for birds. Among bacteria, Bacillus cereus was abundant in all of the engorged females. Bacillus paramycoides and Enterococcus faecium were identified from females feeding on cattle and buffaloes' blood, while Alcaligenes faecalis was found in the gut contents of females that fed on cattle and human blood. The gut bacteria Alca-ligenes faecalis exhibited alpha haemolytic activity. In contrast, Bacillus sp., B. cereus, B. flexus, B. licheniformis, B. thuringiensis, B. paramycoides, E. faecium, Paenibacillus sp. and Pseudomonas sp. exhibited beta haemolysis. This is the first report on the composition of gut bacteria, with particular emphasis on the haemolytic bacteria of C. oxystoma with different host blood meals. The pathogenic bacteria B. cereus, B. licheniformis and A. faecalis within the females could potentially impact pathogen acquisition and increase the probability of their zoonotic transmissibility. K E Y W O R D S biting midge, blood meal, gut bacteria, host, vector
To fish-out novel salt-tolerance genes, metagenomic DNA of moderately saline sediments of India’s largest hypersaline Sambhar Lake was cloned in fosmid. Two functionally-picked clones helped the Escherichia coli host to tolerate 0.6 M NaCl. Deep sequencing of their fosmid DNA insert revealed 32–37% of genes to encode transporters, mostly belonging to ABC (ATP-Binding Cassette)-type, but none specific to channel Na⁺. The complete metagenome sequence of Sambhar Lake brines, and reanalysed data of twelve other hypersaline metagenome sequences, however, have only around 5% transporter genes, suggesting metagenomic DNA fragments being biasedly-cloned during functional screening. Almost half of the ~ 40 Kb inserts in the two clones was shared, and encode several transporters, and some transposase. This advocates that these transporter-loaded DNA lengths are shuttled among microorganisms of hypersaline environments. Interestingly, one clone showed retarded growth with prominent cell disruptions in scanning electron microscopic images, when fosmid copy number was increased or transporters were NaCl-induced. Its cloned insert exclusively has three genes, encoding a structurally functional ATP-binding protein and its efflux component, whose possible overexpression led to membrane crowding and cell rupture. Thus, microorganisms thriving in hypersaline lakes have plentiful ABC transporters that are mutually shared among themselves. These novel salt tolerance genes have future agricultural biotechnological potential.
Supply chains and other complex systems can be effectively managed and optimised with the help of optimal control techniques. Optimal control, as used in supply chain management, is the process of using mathematical optimisation techniques to identify the best course of action for controlling a given objective function over time. Modeling the supply chain’s dynamics, which include elements like production rates, inventory levels, demand trends, and transportation constraints, is the best control strategy when applied to a supply chain. In this study, we have considered that production rate is an unknown function of time, which is a controlling function. The demand for the product is taken as a function of price and time. The emission of carbon is taken as a linear function of the production rate of the system. To solve the suggested supply chain system, we have used an optimal control approach for determining the unknown production rate. To find the optimal values of the objective function as well as the decision variables, we have used different meta-heuristic algorithms and compared their results. It is observed that the equilibrium optimizer algorithm performed better than other algorithms used. Finally, a sensitivity analysis is performed, which is presented graphically in order to choose the best course of action.
A rapid development strategy was successfully implemented to create a suEPSR111459pramolecular metallogel comprising Mn(II) (referred to as MnA-TA) and Zn(II) (referred to as ZnA-TA) ions. These gels were formed using L-(+)-tartaric acid as a low molecular weight gelator in DMF medium at ambient conditions. Rheological analysis was employed to assess the mechanical stability of the synthesized MnA-TA and ZnA-TA metallogel. The results of the analysis revealed the gel’s impressive resilience when subjected to various angular frequencies and levels of oscillator stress. The exploration of MnA-TA and ZnA-TA metallogel’s distinct morphological patterns was conducted using FESEM images. FESEM analysis revealed that MnA-TA metallogel exhibited a flake-like hierarchical network structure, while ZnA-TA metallogel demonstrated a diamond-shaped architecture. EDX analysis was utilized for elemental mapping, confirming the presence of primary chemical constituents in the metallogels. The formation strategy and nature of the gel materials were examined through FT-IR spectroscopy and PXRD analysis. The synthesized metallogels exhibited semiconducting properties, as confirmed by optical band-gap measurements. Furthermore, a metal-semiconductor junction-based device was successfully fabricated by combining Al metal with Mn(II)- and Zn(II)-metallogels. The device displayed nonlinear charge transport behavior, resembling that of a Schottky diode, as evidenced by its I-V characteristic. This indicates the potential use of the sandwich-like configuration of ITO/MnA-TA metallogel/Al and ITO/ZnA-TA metallogel/Al in the development of advanced electronic devices based on supramolecular Mn(II)- and Zn(II)-metallogels. Notably, the direct utilization of tartaric acid and Mn(II)/Zn(II) sources in the MnA-TA and ZnA-TA metallogels presents an innovative approach, highlighting their suitability as semiconducting materials for device fabrication. This study delves into the multifunctional applications of MnA-TA and ZnA-TA metallogels, providing valuable insights for researchers in the field of material science. Graphical Abstract Derived from a low molecular weight gelator tartaric acid, supramolecular metallogels composed of Mn(II)- and Zn(II)-ions demonstrate remarkable stability at room temperature offer promising prospects for integration into electronic devices, specifically Schottky barrier diodes, operating effectively at room temperature.
India faces a significant challenge in managing its groundwater resources, with 80% of annual withdrawals primarily for agriculture. This paper focuses on the Damodar Valley Corporation (DVC) canal command area, a crucial agricultural region, relying on both surface (canal) and groundwater for irrigation, especially for boro paddy during the dry season. Using the FAO’s CropWat 8.0 model, the study estimates irrigation water requirements and proposes strategies to optimize water usage. The analysis reveals a stark disparity between irrigation demand and actual canal water supply, leading to significant reliance on groundwater. Precise estimation of irrigation needs and efficient scheduling are urgently needed to reduce pressure on groundwater resources. The study uses comprehensive data analysis and modeling, considering climatic conditions, crop characteristics, soil types, and irrigation methods. The CropWat 8.0 model, using the Penman–Monteith equation endorsed by FAO, estimates evapotranspiration and irrigation needs. Challenges in the DVC canal command area include poor irrigation efficiency, inadequate water supply, and excessive groundwater use. Solutions proposed include improved canal maintenance, water-saving practices like the System of Rice Intensification (SRI), and policy measures to encourage efficient water use. The study finds 41% and 85% groundwater irrigation share which require to withdrawal 32,708 ham and 268,033 ham groundwater in the irrigable and total command areas, respectively, for the 2021–22 boro season. This outcome highlights the need for scientific irrigation management to ensure water sustainability and agricultural productivity. Implementing these strategies can enhance water use efficiency, systematic watering, mitigate groundwater depletion, and promote sustainable agriculture in the DVC area and similar regions across India. This study serves as a blueprint for policymakers, irrigation authorities, and farmers to collaborate on evidence-based strategies for optimizing water use and ensuring food security in water-stressed regions.
This study examines the hydrodynamic stability of weakly viscoelastic thin film of Walters liquid B″ type on a uniformly heated rigid inclined plane. The current model incorporates a heat flux (HF) boundary condition, which is a realistic representation. This approach accounts for heat flux and heat loss at the wall–liquid and wall–air interfaces, allowing for an examination of the effects of a nonvanishing temperature gradient at the top of the rigid wall. This consideration is essential, as maintaining a constant temperature throughout the wall in laboratory settings poses significant challenges. A Benney-type evolution equation is derived using the long-wave expansion of the flow variables, describing the film thickness as a function of x, t. A linear stability analysis in normal mode is conducted to determine the onset of instability to the critical Reynolds number. The linear study indicates the dual role of the wall film Biot number (Bw). For small values of (Bw), a destabilizing effect is observed; however, upon reaching a critical value, a stabilizing effect is produced. The linear study confirms that the presence of Bw consistently results in a destabilizing effect on the viscoelastic parameter. The nonlinear free surface equation is numerically simulated using the Fourier Spectral method. The temporal evolution of hmax and hmin in the presence of (Bw) proves the viscoelastic parameter's destabilizing effect.
The jute hairy caterpillar, Spilosoma obliqua (Lepidoptera: Erebidae) is considered as one of the major threats to jute cultivation. The best eco-friendly methods to combat these jute pests involve administration of nano-biopesticides, as a successful alternative to the toxic chemicals. In this study, a nano-biopesticide formulation containing green synthesized silver nanoparticles (Ag NPs) using Ocimum sanctum leaf extract has been proposed. The characterization studies confirmed significant interactions between the Ag NPs and bioactive components in the nano-biopesticide formulation. The comparative analysis of the aforementioned larval mortality showed better responses in the nano-biopesticide formulation rather than the crude (pure) leaf extract. The LC50 values were calculated both for the nano-biopesticide formulation and pure extract after 24, 48 and 72 h of treatment. The nano-biopesticide formulation was found to exhibit the lowest and much promising LC50 value of 93.21 ppm, 23.38 ppm, 5.96 ppm relative to that of LC50 values of 1590.74 ppm, 459.30 ppm, 102.68 ppm respectively for the crude leaf extract. The synergistic interactions between the components in the nano-biopesticide formulation can be associated with its greater effectiveness as a promising toxicant to the larvae of the jute caterpillar compared to the mere leaf extract, thereby, demonstrating a greener and safer method for effective pest management.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
997 members
Anirban Ash
  • Department of Zoology
Debashis Dey
  • Department of Mathematics
Swati Mukhopadhyay
  • Department of Mathematics
Debasis Das
  • Department of Chemistry
Information
Address
Barddhamān, India