National Institute of Technology Durgapur

Cellulose is the biosynthetic product from plants, animals and bacteria. Cellulose is the most abundant polymer having long linear chain like structure composed of (1,4) linked β-D glucopyranosyl units assembled into hierarchical structures of microfibrils with excellent strength and stiffness. And 'nanocellulose' refers to the cellulosic materials with defined nano-scale structural dimensions. They may be cellulose nanocrystal (CNC or NCC), cellulose nanofibers (CNF) or bacterial nanocellulose. Nanocellulose is non-toxic, biodegradable and biocompatible with no adverse effects on health and environment. Due to its low thermal expansion coefficient, high aspect ratio, better tensile strength, good mechanical and optical properties, they find many applications in thermo-reversible and tenable hydrogels, paper making, coating additives, food packaging, flexible screens, optically transparent films and light weight materials for ballistic protection, automobile windows. It also find potential in biopharmaceutical applications such as in drug delivery and for fabricating temporary implants with PHB like sutures, stents etc.

Abstract Background In recent years, green synthesis of silver nanoparticles (AgNPs) has gained much interest from chemists and researchers. In this concern, Indian flora has yet to divulge innumerable sources of cost-effective non-hazardous reducing and stabilizing compounds utilized in preparing AgNPs. This study investigates an efficient and sustainable route of AgNP preparation from 1 mM aqueous AgNO 3 using leaf extracts of three plants, Musa balbisiana (banana), Azadirachta indica (neem) and Ocimum tenuiflorum (black tulsi), well adorned for their wide availability and medicinal property. Methods AgNPs were prepared by the reaction of 1 mM silver nitrate and 5% leaf extract of each type of plant separately. the AgNPs were duely characterized and tested for their antibacterial activity and toxicity. Results The AgNPs were characterized by UV-visible (vis) spectrophotometer, particle size analyzer (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS). Fourier transform infrared spectrometer (FTIR) analysis was carried out to determine the nature of the capping agents in each of these leaf extracts. AgNPs obtained showed significantly higher antimicrobial activities against Escherichia coli ( E. coli ) and Bacillus sp. in comparison to both AgNO 3 and raw plant extracts. Additionally, a toxicity evaluation of these AgNP containing solutions was carried out on seeds of Moong Bean ( Vigna radiata ) and Chickpea ( Cicer arietinum ). Results showed that seeds treated with AgNP solutions exhibited better rates of germination and oxidative stress enzyme activity nearing control levels, though detailed mechanism of uptake and translocation are yet to be analyzed. Conclusion In totality, the AgNPs prepared are safe to be discharged in the environment and possibly utilized in processes of pollution remediation. AgNPs may also be efficiently utilized in agricultural research to obtain better health of crop plants as shown by our study.

In order to evaluate the effect of the functional group present in the ligand backbone towards corrosion inhibition performances, three Schiff-base molecules namely, (E)-4-((2-(2,4-dinitrophenyl)hydrazono)methyl)pyridine (L(1)), (E)-4-(2-(pyridin-4-ylmethylene)hydrazinyl)benzonitrile (L(2)) and (E)-4-((2-(2,4-dinitrophenyl)hydrazono)methyl)phenol (L(3)) were synthesized and used as corrosion inhibitors on mild steel in 1 M HCl medium. The corrosion inhibition effectiveness of the studied inhibitors was investigated by weight loss and several sophisticated analytical tools such as potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Experimentally obtained results revealed that corrosion inhibition efficiencies followed the sequence: L(3) > L(1) > L(2). Electrochemical findings showed that inhibitors impart high resistance towards charge transfer across the metal-electrolyte interface and behaved as mixed type inhibitors. Scanning electron microscopy (SEM) was also employed to examine the protective film formed on the mild steel surface. The adsorption as well as inhibition ability of the inhibitor molecules on the mild steel surface was investigated by quantum chemical calculation and molecular dynamic (MD) simulation. In quantum chemical calculations, geometry optimized structures of the Schiff-base inhibitors, electron density distribution in HOMO and LUMO and Fukui indices of each atom were employed for their possible mode of interaction with the mild steel surfaces. MD simulations revealed that all the inhibitors molecules adsorbed in parallel orientation with respect to the Fe(110) surface.

Corrosion inhibition performance of 2-(2-hydroxybenzylideneamino)phenol (L(1)), 2-(5-chloro-2-hydroxybenzylideneamino)phenol (L(2)) and 2-(2-hydroxy-5-nitrobenzylideneamino)phenol (L(3)) on the corrosion behaviour of mild steel surface in a 1 M hydrochloric acid (HCl) solution is investigated by sophisticated analytical methods like potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss measurements. Polarization studies showed that all the compounds are mixed type (cathodic and anodic) inhibitors and the inhibition efficiency (η%) increased with increasing inhibitor concentration. The inhibition actions of these Schiff base molecules are discussed in view of blocking the electrode surface by means of adsorption of the inhibitor molecule obeying the Langmuir adsorption isotherm. Scanning electron microscopy (SEM) studies of the metal surfaces confirmed the existence of an adsorbed film. Density functional theory (DFT) and molecular dynamics (MD) simulation have been used to determine the relationship between molecular configuration and their inhibition efficiencies. The order of inhibition performance obtained from experimental results is successfully verified by DFT and MD simulation.

Tin dioxide (SnO₂) used in various applications due to suitable band gap and tunable conductivity. It has excellent thermal, mechanical and chemical stability.

The biodiversity of wheat-associated bacteria from the northern hills zone of India was deciphered. A total of 247 bacteria was isolated from five different sites. Analysis of these bacteria by amplified ribosomal DNA restriction analysis (ARDRA) using three restriction enzymes, AluI, MspI and HaeIII, led to the grouping of these isolates into 19–33 clusters for the different sites at 75 % similarity index. 16S rRNA gene based phylogenetic analysis revealed that 65 %, 26 %, 8 % and 1 % bacteria belonged to four phyla, namely Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes, respectively. Overall, 28 % of the total morphotypes belonged to Pseudomonas followed by Bacillus (20 %), Stenotrophomonas (9 %), Methylobacterium (8 %), Arthrobacter (7 %), Pantoea (4 %), Achromobacter, Acinetobacter, Exiguobacterium and Staphylococcus (3 %), Enterobacter, Providencia, Klebsiella and Leclercia (2 %), Brevundimonas, Flavobacterium, Kocuria, Kluyvera and Planococcus (1 %). Representative strains from each cluster were screened in vitro for plant growth promoting traits, which included solubilisation of phosphorus, potassium and zinc; production of ammonia, hydrogen cyanide, indole-3-acetic acid and siderophore; nitrogen fixation, 1-aminocyclopropane-1-carboxylate deaminase activity and biocontrol against Fusarium graminearum, Rhizoctonia solani and Macrophomina phaseolina. Cold-adapted isolates may have application as inoculants for plant growth promotion and biocontrol agents for crops growing under cold climatic conditions.

The diversity of culturable Bacilli was investigated in six wheat cultivating agro-ecological zones of India viz: northern hills, north western plains, north eastern plains, central, peninsular, and southern hills. These agro-ecological regions are based on the climatic conditions such as pH, salinity, drought, and temperature. A total of 395 Bacilli were isolated by heat enrichment and different growth media. Amplified ribosomal DNA restriction analysis using three restriction enzymes AluI, MspI, and HaeIII led to the clustering of these isolates into 19-27 clusters in the different zones at >70% similarity index, adding up to 137 groups. Phylogenetic analysis based on 16S rRNA gene sequencing led to the identification of 55 distinct Bacilli that could be grouped in five families, Bacillaceae (68%), Paenibacillaceae (15%), Planococcaceae (8%), Staphylococcaceae (7%), and Bacillales incertae sedis (2%), which included eight genera namely Bacillus, Exiguobacterium, Lysinibacillus, Paenibacillus, Planococcus, Planomicrobium, Sporosarcina, and Staphylococcus. All 395 isolated Bacilli were screened for their plant growth promoting attributes, which included direct-plant growth promoting (solubilization of phosphorus, potassium, and zinc; production of phytohormones; 1-aminocyclopropane-1-carboxylate deaminase activity and nitrogen fixation), and indirect-plant growth promotion (antagonistic, production of lytic enzymes, siderophore, hydrogen cyanide, and ammonia). To our knowledge, this is the first report for the presence of Bacillus endophyticus, Paenibacillus xylanexedens, Planococcus citreus, Planomicrobium okeanokoites, Sporosarcina sp., and Staphylococcus succinus in wheat rhizosphere and exhibit multifunctional PGP attributes. These niche-specific and multifarious PGP Bacilli may serve as inoculants for crops growing in respective climatic conditions.

Conversion of a color image into a grayscale image inclusive of salient features is a complicated process. The converted grayscale image may lose contrasts, sharpness, shadow, and structure of the color image. To preserve contrasts, sharpness, shadow, and structure of the color image a new algorithm has proposed. To convert the color image into grayscale image the new algorithm performs RGB approximation, reduction, and addition of chrominance and luminance. The grayscale images generated using the algorithm in the experiment confirms that the algorithm has preserved the salient features of the color image such as contrasts, sharpness, shadow, and image structure.

The three-dimensional quasi-steady vortex flow field around circular piers in a quasi-equilibrium scour hole under a clear water regime has been investigated experimentally. The main characteristic features of the flow, to be modeled, are a relatively large secondary vortex flow within the scour hole and skewed velocity distributions along the circumference of the pier. The flow field has been divided into a number of parts according to the flow characteristics. The components of quasi-steady velocity for different parts have been theoretically expressed in the form of equations satisfying the continuity equation and the requirements of fitting an individual profile of the measured velocity components. Using the suitable functions, the equations of the velocity components derived for different parts have been combined and matched at the junctions of these parts to get a single equation for each velocity component. The measured data have been utilized to determine the coefficients and exponents used in these equations through curve fittings. The proposed flow model, which corresponds closely with the observations, can be utilized to simulate the flow field in prototype.

Abstract Gradual increase in concentration of carbon dioxide (CO 2 ) in the atmosphere due to the various anthropogenic interventions leading to significant alteration in the global carbon cycle has been a subject of worldwide attention and matter of potential research over the last few decades. In these alarming scenario microalgae seems to be an attractive medium for capturing the excess CO 2 present in the atmosphere generated from different sources such as power plants, automobiles, volcanic eruption, decomposition of organic matters and forest fires. This captured CO 2 through microalgae could be used as potential carbon source to produce lipids for the generation of biofuel for replacing petroleum-derived transport fuel without affecting the supply of food and crops. This comprehensive review strives to provide a systematic account of recent developments in the field of biological carbon capture through microalgae for its utilization towards the generation of biodiesel highlighting the significance of certain key parameters such as selection of efficient strain, microalgal metabolism, cultivation systems (open and closed) and biomass production along with the national and international biodiesel specifications and properties. The potential use of photobioreactors for biodiesel production under the influence of various factors viz., light intensity, pH, time, temperature, CO 2 concentration and flow rate has been discussed. The review also provides an economic overview and future outlook on biodiesel production from microalgae.

Network security is an important aspect of information sharing. Attempts have been made to remove various insecurities over internet. For this, many technological implementations and security policies have been developed. The amount of data, transferred, is not a factor. The basic factor is, how much security, the channel provides while transmitting data. Cryptography is one such technique, which allows secure data transmission without losing its confidentiality and integrity. Based on the key distribution, cryptography is further classified into two major types-Symmetric Key Cryptography and Asymmetric Key Cryptography. In this paper, we have surveyed the traditional algorithms, along with the proposed algorithms based on their pros and cons, related to Symmetric and Asymmetric Key Cryptography. We have also compared the importance of both these cryptographic techniques. The proposed algorithms proved to be highly efficient in their respective grounds but there are certain areas that remained open, related to these algorithms, and have not yet been thoroughly discussed. This paper also presents an appropriate future scope related to these open fields.

We put forth our opinion regarding the enhanced plasticity and modulation of mechanical properties of polymeric films obtained through electrospinning process in this article. In majority of the pharmaceutical, biomedical, and packaging applications, it is desirable that polymer based matrices should be soft, flexible, and have a moderate toughness. In order to convert inflexible and brittle polymers, adjuvants in the form of plasticizers are added to improve the flexibility and smoothness of solvent casted polymer films. However, many of these plasticizers are under scrutiny for their toxic effects and environmental hazards. In addition, plasticizers also increase the cost of end products. This has motivated the scientific community to investigate alternate approaches. The changes imparted in membrane casted by electrospinning were tried to be proved by SEM, Mechanical property study, DSC and XRD studies. We have showed dramatic improvement in flexibility of poly(ε-caprolactone) based nanofiber matrix prepared by electrospinning method whereas solvent casting method without any plasticizer produced very brittle, inflexible film of PCL. Modulation capacity of mechanical properties is also recorded. We tried to support our opinion by citing several similar findings available in the open literature. The electrospinning method helps in plasticization and in tuning mechanical properties.

The connective hard tissues bone and teeth are highly porous on a micrometer scale, but show high values of compression strength at a relatively low weight. The fabrication of porous materials has been actively researched and different processes have been developed that vary in preparation complexity and also in the type of porous material that they produce. Methodologies are available for determination of pore properties. The purpose of the paper is to give an overview of these methods, the role of porosity in natural porous materials and the effect of pore properties on the living tissues. The minimum pore size required to allow the ingrowth of mineralized tissue seems to be in the order of 50 µm: larger pore sizes seem to improve speed and depth of penetration of mineralized tissues into the biomaterial, but on the other hand impair the mechanical properties. The optimal pore size is therefore dependent on the application and the used material.

The adsorption behavior and corresponding inhibition mechanism of two aminobenzonitrile derivatives in aqueous acidic medium on steel surfaces have been investigated using quantum chemical calculations and molecular dynamics (MD) simulations.

Healthcare sector is probably the most benefited from the applications of nanotechnology. The nanotechnology, in the forms of nanomedicine, nanoimplants, nanobiosensors along with the internet of nano things (IoNT), has the potential to bring a revolutionizing advancement in the field of medicine and healthcare services. The primary aim of this paper is to explore the clinical and medical possibilities of these different implementations of nanotechnology. This paper provides a comprehensive overview of nanotechnology, biosensors, nanobiosensors, and IoNT. Furthermore, multilevel taxonomies of nanotechnology, nanoparticles, biosensors, nanobiosensors, and nanozymes are presented. The potential medical and clinical applications of these technologies are discussed in details with several examples. This paper specifically focuses on IoNT and its role in healthcare. In addition to describing a general architecture of IoNT for healthcare, the communication architecture of the IoNT is also explained. The challenges in the successful realization of IoNT are also discussed critically, along with a special discussion on internet of bio-nano things (IoBNT) and its potential in making IoNT more compatible to human body.

One of the major challenges in wireless sensor network (WSN) research is to curb down congestion in the network's traffic, without compromising with the energy of the sensor nodes. Congestion affects the continuous flow of data, loss of information, delay in the arrival of data to the destination and unwanted consumption of significant amount of the very limited amount of energy in the nodes. Obviously, in healthcare WSN applications, particularly in the ones that cater to medical emergencies or in the ones that closely monitor critically ailing patients, it is desirable in the first place to avoid congestion from occurring and even if it occurs, to reduce the loss of data due to congestion. In this work, we address the problem of congestion in the nodes of healthcare WSN using a learning automata (LA)-based approach. Our primary objective in using this approach is to adaptively make the processing rate (data packet arrival rate) in the nodes equal to the transmitting rate (packet service rate), so that the occurrence of congestion in the nodes is seamlessly avoided. We maintain that the proposed algorithm, named as learning automata-based congestion avoidance algorithm in sensor networks (LACAS), can counter the congestion problem in healthcare WSNs effectively. An important feature of LACAS is that it intelligently' learns' from the past and improves its performance significantly as time progresses. Our proposed LA based model was evaluated using simulations representing healthcare WSNs. The results obtained through the experiments with respect to performance criteria having important implications in the healthcare domain, for example, the number of collisions, the energy consumption at the nodes, the network throughput, the number of unicast packets delivered, the number of packets delivered to each node, the signals received and forwarded to the medium access control (MAC) layer, and the change in energy consumption with variation in transmission range, have shown that the proposed algorithm is capable of successfully avoiding congestion in typical healthcare WSNs requiring a reliable congestion control mechanism.

The advancement and popularity of smartphones have made it an essential and all-purpose device. But lack of advancement in battery technology has held back its optimum potential. Therefore, considering its scarcity, optimal use and efficient management of energy are crucial in a smartphone. For that, a fair understanding of a smartphone’s energy consumption factors is necessary for both users and device manufacturers, along with other stakeholders in the smartphone ecosystem. It is important to assess how much of the device’s energy is consumed by which components and under what circumstances. This paper provides a generalized, but detailed analysis of the power consumption causes (internal and external) of a smartphone and also offers suggestive measures to minimize the consumption for each factor. The main contribution of this paper is four comprehensive literature reviews on: 1) smartphone’s power consumption assessment and estimation (including power consumption analysis and modelling); 2) power consumption management for smartphones (including energy-saving methods and techniques); 3) state-of-the-art of the research and commercial developments of smartphone batteries (including alternative power sources); and 4) mitigating the hazardous issues of smartphones’ batteries (with a details explanation of the issues). The research works are further subcategorized based on different research and solution approaches. A good number of recent empirical research works are considered for this comprehensive review, and each of them is succinctly analysed and discussed.

To minimize electromagnetic (EM) pollution, two key parameters, namely, intrinsic wave impedance matching and intense absorption of incoming EM radiation, must satisfy the utmost requirements. To target these requirements, soft conducting composites consisting of binary blends of polycarbonate (PC) and poly(vinylidene fluoride) (PVDF) were designed with doped multiwalled carbon nanotubes (MWCNTs) and a three-dimensional cross-linked graphene oxide (GO) framework doped with ferrite nanoparticles. The doping of α-MnO2 onto the MWCNTs ensured intrinsic wave impedance matching in addition to providing conducting pathways, and the ferrite-doped cross-linked GO facilitated the enhanced attenuation of the incoming EM radiation. This unique combination of magnetodielectric coupling led to a very high electromagnetic shielding efficiency (SE) of −37 dB at 18 GHz, dominated by absorption-driven shielding. The promising results from the composites further motivated us to rationally stack individual composites into a multilayer architecture following an absorption–multiple reflection–absorption pathway. This resulted in an impressive SE of −57 dB for a thin shield of 0.9-mm thickness. Such a high SE indicates >99.999% attenuation of the incoming EM radiation, which, together with the improvement in structural properties, validates the potential of these materials in terms of applications in cost-effective and tunable solutions.

Arabidopsis thaliana CALMODULIN7 (CAM7), a unique member of the calmodulin gene family, plays a crucial role as a transcriptional regulator in seedling development. The elongated HYPOCOTYL5 (HY5) bZIP protein, an integrator of multiple signaling pathways, also plays an important role in photomorphogenic growth and light-regulated gene expression. CAM7 acts synergistically with HY5 to promote photomorphogenesis at various wavelengths of light. Although the genetic relationships between CAM7 and HY5 in light-mediated seedling development have been demonstrated, the molecular connectivity between CAM7 and HY5 is unknown. Furthermore, whereas HY5-mediated gene regulation has been fairly well investigated, the transcriptional regulation of HY5 is largely unknown. Here, we report that HY5 expression is regulated by HY5 and CAM7 at various wavelengths of light and also at various stages of development. In vitro and in vivo DNA-protein interaction studies suggest that HY5 and CAM7 bind to closely located T/G- and E-box cis-acting elements present in the HY5 promoter, respectively. Furthermore, CAM7 and HY5 physically interact and regulate the expression of HY5 in a concerted manner. Taken together, these results demonstrate that CAM7 and HY5 directly interact with the HY5 promoter to mediate the transcriptional activity of HY5 during Arabidopsis seedling development.

Abstract Topological index is a numerical value associated with a chemical constitution for correlation of chemical structure with various physical properties, chemical reactivity or biological activity. In this work, some new indices based on neighborhood degree sum of nodes are proposed. To make the computation of the novel indices convenient, an algorithm is designed. Quantitative structure property relationship (QSPR) study is a good statistical method for investigating drug activity or binding mode for different receptors. QSPR analysis of the newly introduced indices is studied here which reveals their predicting power. A comparative study of the novel indices with some well-known and mostly used indices in structure-property modelling and isomer discrimination is performed. Some mathematical properties of these indices are also discussed here.