Showing papers by "North Eastern Regional Institute of Science and Technology published in 2016"
TL;DR: In this paper, a suitable alternative to the FAO-56 Penman-Monteith (FAO56PM) equation for calculating reference evapotranspiration (ET0) from chosen temperature and radiation based models utilizing monthly meteorological data from 30 destinations in diverse agro-ecological regions of the Northeast (NE) India i.e., Assam Bengal Plain (ABP), eastern Himalaya (EH), and the northeastern hilly (NEH) region.
82 citations
TL;DR: In this paper, magnetite nanoparticles were synthesized by chemical co-precipitation using ferrous and ferric chloride as iron precursors and used for aqueous Pb 2+ removal at different initial pHs, equilibrium time, temperature and adsorbent/adsorbate concentrations.
Abstract: Monodispersed magnetite nanoparticles [Fe 3 O 4 -NPs] were synthesized by chemical co-precipitation using ferrous and ferric chloride as iron precursors. The composition, surface properties and morphology were investigated using X-ray powder diffraction, transmission electron microscopy, dynamic light scattering, scanning electron microscopy and Fourier transform infrared spectroscopy. Synthesized magnetite nanoparticles have zeta potential of +22.0 mV and an energy bandgap of 2.2 eV. These NPs were used for aqueous Pb 2+ removal at different initial pHs, equilibrium time, temperature and adsorbent/adsorbate concentrations. Pb 2+ adsorption was increased with rise in solution pH. Almost 100% Pb 2+ removal was achieved [at magnetite NPs dose: 0.2 g/L; Pb 2+ concentration: 50 mg/L; pH 5.0; shaking speed: 200 rpm; temperature: 25 °C and equilibrium time: 30 min]. Pseudo-first and pseudo-second order kinetic equations were applied to evaluate the kinetic data. Pseudo-second-order rate equation better fitted the data. Spent NPs were regenerated using 0.005 M HNO 3 . Exhausted magnetite NPs were successfully recovered from aqueous system using a simple magnet. These magnetite NPs can also be used for Pb 2+ removal from waters having high concentration of suspended particles.
74 citations
TL;DR: In this paper, the authors predicted the probable distribution of two invasive plant species Mimosa diplotricha Sauvalle and Mikania micrantha Kunth in a protected tropical grassland of Rajiv Gandhi Orang National Park, Assam, Northeast India using Maximum Entropy (MaxEnt) distribution modelling algorithm.
46 citations
TL;DR: In this paper, six composites of hydroxyapatite (HAp) powders with SrCO3 and ZrO2 were synthesized to study the morphological and tribological behaviour.
Abstract: Hydroxyapatite (HAp) powders were prepared successfully using microwave-assisted co-precipitation method. HAp powder was characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy for structural confirmation of the prepared material. Further, six composites of HAp with SrCO3 and ZrO2 were synthesized to study the morphological and tribological behaviour. Three composites of HAp with three varying 2, 4, 6 wt% of SrCO3 and similarly other three with ZrO2 were prepared using solid-state route method. Scanning electron microscopy (SEM) analysis confirmed that the presence of SrCO3 and ZrO2 among HAp particles helps in grain growth during the sintering processes. The tribological study reveald that the inclusion of SrCO3 and ZrO2 in pure HAp enhanced the resistance to wear and specific wear rate. The average grain size of HAp–ZrO2 was observed more in comparision to the average grain size of the HAp–SrCO3. The values of the specific wear rate and wear of HAp–SrCO3 and HAp–ZrO2 composite ceramics lies in the range from 4.13,239 × 10−5 to 5.44517 × 10−5 mm3/Nm and 4.68693 × 10−5 to 6.10099 × 10−5 mm3/Nm, respectively.
24 citations
TL;DR: In this article, a random sampling approach was adopted for enumeration of floristic diversity and community characteristics analysis of the Talle Wildlife Sanctuary, where 63 species were recorded from the sampled area (0.2
24 citations
TL;DR: This work proposes a new method, Weighted Edge based Clustering (WEC), to identify protein complexes based on the weight of the edge between two interacting proteins, where the weight is defined by the edge clustering coefficient and the gene expression correlation between the interacting proteins.
24 citations
TL;DR: Triorganotin(IV) complexes of azo-carboxylic acids derived from amino benzoic acids and resorcinol were synthesized by the reaction of 2/4-(2,4-dihydroxy-phenylazo)-benzoic acid with appropriate triorganotin( IV) chlorides [R = Me (1 and 3), Ph (2 and 4) and Bu (5)] in presence of triethylamine as discussed by the authors.
22 citations
TL;DR: In this paper, an attempt is made to check the suitability of TPM approach and present software to estimate reference evapotranspiration based on TPM and Hargreaves-Samani (HS) method by using Visual Basic Environment.
Abstract: In this study, an attempt is made to check the suitability of TPM approach and present software to estimate reference evapotranspiration based on TPM and Hargreaves–Samani (HS) method by using Visual Basic Environment. Considering the FAO-56 Penman–Monteith (FAOPM) as the standard model, the comparative performances of selected methods were evaluated under the climatic condition of Umaim, Meghalaya, India. Using the Root Mean Square Error (RMSE)’ and ‘correlation coefficient (r)’ as statistical measures of ‘goodness-of-fit’ the regression analysis was carried out. Based on the regression analysis TPM (RMSE = 0.014 mm day−1, r = 0.92) was found better followed by HS (RMSE = 0.054 mm day−1, r = 0.87). The average overestimate (e.g. 1.97 %) by TPM were found to be in close agreement with the FAOPM. These results support the use of the TPM approach under limiting climatic data conditions for Umaim.
21 citations
TL;DR: In this paper, an attempt is made to consider pipe roughness as uncertain parameter and to evaluate the pipe discharges and nodal hydraulic gradient levels accordingly, and it is found that present method is effective in analyzing the uncertainty problem, particularly for large scale networks.
Abstract: The hydraulic analysis of water distribution network is generally done by the conventional method. The obtained results such as pipe discharges, hydraulic gradient level of nodes, nodal concentrations etc., are normally crisp values assuming crisp input parameters. But, in real networks, there are many uncertainties in nodal demands, roughness, length, diameters of pipes, valve operations, water levels in reservoirs, head-discharge characteristics of pumps, etc. The results obtained by the conventional method may not be satisfactory in practice. Hence, in this study, an attempt is made to consider pipe roughness as uncertain parameter and to evaluate the pipe discharges and nodal hydraulic gradient levels accordingly. The Genetic Algorithm Optimization based methodology has been used to obtain the unknown parameters at each α-cut level. The hydraulic simulations are done by using EPANET 2 in MATLAB environment. The maximum and minimum values of pipe discharges and nodal hydraulic gradient levels are obtained in each simulation run. The results show that the required time to run the simulation is same for all networks irrespective of the size after adopting a particular Genetic Algorithm parameters tuning. The obtained results are compared with past studies and it is found that present method is effective in analyzing the uncertainty problem, particularly for large scale networks. The results of pipe discharges are found to vary at 30, 48.3, 58 and 9 % and of the hydraulic heads at nodes at 3.17 m, 4.3 m, 2.2 m and 12.64 m for the selected problems taken from the literature. This study would help to analyze the pipe network under the conditions of uncertainty in input parameters.
21 citations
TL;DR: In this article, Diorganotin(IV) complexes with (E)-5-((2-carboxyphenyl)diazenyl)-2-hydroxy benzoic acid [H3L] were synthesized by reacting the sodium salt of the azo-dicarboxylic acid ligand [Na2HL] with an appropriate diorgan-IV dichloride in anhydrous methanol.
Abstract: Diorganotin(IV) complexes with (E)-5-((2-carboxyphenyl)diazenyl)-2-hydroxy benzoic acid [H3L] were synthesized by reacting the sodium salt of the azo-dicarboxylic acid ligand [Na2HL] with an appropriate diorganotin(IV) dichloride [R = 1 (Me), 2 (Bu) and 3 (Ph)] in anhydrous methanol. The complexes were characterized using elemental analysis, UV, IR, NMR and mass spectrometry. 119Sn NMR study of complexes 1 and 2 indicates the presence of exo-and endo-cyclic tin atoms in the complexes and both the tin atoms are suggested to have 5-coordinate geometry in solution; in complex 3, a single 119Sn-resonance was observed in the range specified for a 4-coordinate structure. The molecular structure of H3L and its dimethyltin(IV) complex {[Me2SnHLSnMe2]O}2 (1) were determined using X-ray crystallography. The structure of 1 reveals that the compound is a centro-symmetric cyclic tetranuclear tin complex which contains a Sn2O4 core. In the structure, the central Sn2O2 ring is connected to two exo-cyclic tin atoms by two μ3-oxo oxygen atoms. Each exo- and endo-cyclic tin atom exhibited a five coordinate distorted trigonal bipyramidal geometry and suggested that the five coordinate structure of the complex in the solid state is also retained in solution. Topological studies of the azo-dicarboxylic acid ligand [H3L] and its cyclic tetranuclear dimethyltin(IV) complex were also carried out. The H-bonding network in H3L has been topologically classified as 2-periodic three-dimensional KIa. For the molecular packing in 1, a multilevel topological description is provided. Finally, the complexes have been screened for α-glucosidase enzyme inhibition assay as an indicator for their anti-diabetic properties and the results of the tests showed that they had better anti-diabetic activity than the standard drug acarbose.
21 citations
TL;DR: In this paper, a multi-layer feed forward ANN architecture 4-16-1 working on gradient descent back propagation algorithm is found optimum and is statistically validated by conducting hypothesis tests for predicting surface roughness in wire-cut electrical discharge machining (WEDM) of Inconel 825 aerospace alloy.
TL;DR: In this article, the authors proposed to modify the expression for the Larson-Miller parameter for predicting the creep life of materials, and the results reveal that the parameter is a linear function of applied stress.
Abstract: Larson–Miller parameter is the most extensively used extrapolation technique for predicting creep life of metallic materials. In this technique, the Larson–Miller parameter (P) is empirically expressed as: P = T [C + log(t)] where the C is considered as a constant. This is under the assumption that iso-stress lines in the plot of log(t) versus 1/T when extended, intersects the vertical axis at 1/T = 0, which corresponds to the Larson–Miller constant C. Analysis of the literature data reveals that the intersection of the iso-stress lines at a common point is rarely met in practice. The present paper is aimed at investigating the value of Larson–Miller constant C in the Larson–Miller parameter technique. Accelerated creep tests on micro-alloyed HP40Nb steel were conducted at constant stresses in the range 47–120 MPa and temperatures 650–1050 °C for the prediction of creep life by Larson–Miller parameter. The results reveal that the Larson–Miller constant C in the expression for P is not a constant, rather, it is a linear function of applied stress. The authors proposed to modify the expression for the Larson–Miller parameter for predicting the creep life of materials.
TL;DR: Various risk factors influencing pain occurrences were identified using logistic regression, and factors like age, gender, hours of peeling, frequency of rest breaks, perceived work fatigue and years of experience were found to be associated with risk of pain in at least one of the body parts.
TL;DR: From this experimental study reflectance reduces 13% to 11% due to plasmonic effect and enhancement in the conversion efficiency of the solar cell.
TL;DR: In this paper, two higher homologous of 5O have been found to exhibit negative optical anisotropy in their studies, which are calamatic interdigitated with unsymmetrical alkyl chain length.
23 May 2016
TL;DR: The experimental results show that the proposed steganographic method has a higher embedding capacity and Peak Signal to Noise Ratio (PSNR) value of the stego image against the cover image.
Abstract: This paper presents a novel steganographic method based on Least Significant Bit (LSB) substitution and 8-neighboring Pixel Value Differencing (8nPVD) for gray scale image in order to improve the embedding capacity with an imperceptible stego image. The proposed method partitions the cover image into some 3×3 non-overlapping pixel blocks in row major order. k-bits of the secret bit stream are embedded in the center pixel of the block using modified LSB substitution. The difference between the center pixel and 8-neighboring pixels are employed to find out the number of bits that can be embedded in the difference value. The method divides the gray levels [0-255] into five different continuous ranges. The number of bits to be embedded is calculated from the range table. The experimental results show that the proposed method has a higher embedding capacity and Peak Signal to Noise Ratio (PSNR) value of the stego image against the cover image. This work also presents a comparison of the embedding capacity and PSNR value of the proposed method with the existing scheme [5], [7].
TL;DR: An efficient and scalable synthesis of the antiepileptic drug (R)-lacosamide and its derivatives has been achieved from commercially available aziridine-(2R)-carboxylate in three simple sequential steps, including regioselective azirazine ring opening, debenzylation followed by acetylation in one pot, and amide formation.
Abstract: An efficient and scalable synthesis of the antiepileptic drug (R)-lacosamide and its derivatives has been achieved from commercially available aziridine-(2R)-carboxylate in three simple sequential steps, including regioselective aziridine ring opening, debenzylation followed by acetylation in one pot, and amide formation. The advantage of this protocol is that the starting material and reagents are commercially available and a single purification by recrystallization is required after all the chemical transformations, providing the final drug in >99.9% ee.
TL;DR: The treatment of a S-nucleophile such as PhSH is found to reduce iron( III)-hydroxyisoporphyrin in the parent iron(III) porphyrIn compound as well as the mechanism for the formation of ring opening products similar to the hydrolytic pathway of verdoheme conversion to biliverdin.
Abstract: The reactions of iron(III) hydroxyisoporphyrin, chloro[5-(hydroxy)-5,10,15,20-tetrakis(4-methyl)-5,21H-porphinato]iron(III) [Fe(4-Me-HTPI)(Cl)](-), 1 and chloro[5-(hydroxy)-5,10,15,20-tetrakis(4-methoxy-5,21H-porphinato]iron(III) [Fe(4-OMe-HTPI)(Cl)](-), 2 with different O(-), N(-) and S(-) nucleophiles have been performed to understand the reactivity of iron isoporphyrins with nucleophiles. The treatment of iron(III) hydroxy isoporphyrin with alcohols is found to form ring opened 19-benzoyl-1-alkoxy-bilin iron complexes. When alkyl amines were used the formation of ring opened 19-benzoyl-1-alkylamine-bilin iron complexes was observed, but heterocyclic N-nucleophiles such as pyridine and imidazole form benzoyl bilinone iron complexes. No role of oxygen was found in these nucleophilic ring opening reactions. The treatment of a S-nucleophile such as PhSH is found to reduce iron(III)-hydroxyisoporphyrin in the parent iron(III) porphyrin compound. The ring opening products were characterized using electronic and ESI-mass spectroscopy. The mechanism for the formation of ring opening products is based on the formation of a tetrahedral intermediate at the carbon atom near the saturated meso carbon atom similar to the hydrolytic pathway of verdoheme conversion to biliverdin.
TL;DR: The molecular structure reported in this article is not purely uniaxial; it has a bending tendency.
Abstract: A detailed study of the different parameters of the higher homologs of the 5O.m (m = 14, 16) series of liquid-crystalline compounds is reported. These are interdigitated compounds with unsymmetrical alkyl chain length. The compounds have a unique nature, unlike the other members of the nO.m series. The molecular structure reported in this article is not purely uniaxial; it has a bending tendency. In this article, we report that both the compounds exhibit negative birefringence. For the optical study, the refractive indices, ne and no, of the sample are measured by the thin-prism technique, using a He–Ne laser beam of wavelength 633 nm. A four-parameter model was used for fitting the experimental results. From the experimentally measured refractive indices, it is possible to compare different parameters with those of the theoretical models.
TL;DR: In this article, a qualitative interpretation in terms of dipole-dipole correlation for both the parallel and the perpendicular components of the dipole moment is given, and the change in the dielectric permittivity and dielectrics anisotropy is made by doping the two compounds separately with dodecanethiol capped silver nanoparticles (0.25% by weight).
Abstract: Dielectric study of the compounds N(4-n-heptyloxy benzylidene)4′-n-butylaniline and N(4-n-heptyloxy benzylidene)4′-n-hexylaniline at low frequency region (1 kHz–1 MHz) is performed using LCR meter (Agilent 4284 A). A qualitative interpretation in terms of dipole–dipole correlation for both the parallel and the perpendicular components of the dipole moment is given. Further study on the change in the dielectric permittivity and the dielectric anisotropy is made by doping the two compounds separately with dodecanethiol capped silver nanoparticles (0.25% by weight). The molecular positional ordering and relative smectic layer distance influences the change of degree (or type) of dipole–dipole pairing.
TL;DR: In this paper, a Kalman filter algorithm is presented for static estimation of power system state variables and IEEE 14 bus system is employed to check the accuracy of this method and the results of Kalman estimation are compared with traditional Weight Least Square (WLS) method and it is observed that Kalman filtering algorithm is numerically more efficient than traditional WLS method.
Abstract: State estimation of power system is an important tool for operation, analysis and forecasting of electric power system. In this paper, a Kalman filter algorithm is presented for static estimation of power system state variables. IEEE 14 bus system is employed to check the accuracy of this method. Newton Raphson load flow study is first carried out on our test system and a set of data from the output of load flow program is taken as measurement input. Measurement inputs are simulated by adding Gaussian noise of zero mean. The results of Kalman estimation are compared with traditional Weight Least Square (WLS) method and it is observed that Kalman filter algorithm is numerically more efficient than traditional WLS method. Estimation accuracy is also tested for presence of parametric error in the system. In addition, numerical stability of Kalman filter algorithm is tested by considering inclusion of zero mean errors in the initial estimates.
TL;DR: The new concept of a fixed set for a set valued map with set valued domain in the setting of metric space endowed with a directed graph is defined and its relation with the start set is established.
Abstract: In this article, we define the new concept of a fixed set for a set valued map with set valued domain in the setting of metric space endowed with a directed graph. This notion of fixed set is analogous to the notion of a fixed point for a multivalued map and not for a classical single-valued map. We also introduce the new concept of the start set of a graph whose vertices are closed and bounded subsets of a metric space. Characterizations for such a graph to have a start set are given. Further, the notion of a self-path set valued map is defined and its relation with the start set is established. Finally, the existence of fixed sets is established in this context.
01 Jan 2016
TL;DR: This paper proposes a detection scheme based on Apriori algorithm which detects colluding SSDF attack and supports the validity of the proposed scheme through extensive simulation results.
Abstract: We use collaborative sensing in a cognitive radio network for a more accurate sensing decision. Individual radio nodes sends its local sensing report to the fusion center (FC), which combines the local sensing reports using some fusion rule thereby arriving at a final sensing decision. However, a malicious node may launch the Spectrum Sensing Data Falsification (SSDF) attack in which the local sensing report is falsified before it reaches the fusion center (FC). This is done so as to adversely influence the final sensing decision. The attack can be more severe if the malicious nodes collude. In this paper, we propose a detection scheme based on Apriori algorithm which detects colluding SSDF attack. We support the validity of the proposed scheme through extensive simulation results.
TL;DR: In this paper, a compact FR4-based CPW-fed tri-band antenna for wireless applications is proposed and investigated, which provides three different impedance bandwidths of 0.57, 0.98 and 1.59 GHz.
Abstract: In this paper we propose and investigate a unique compact FR4 based CPW-fed tri-band antenna for wireless applications. The antenna comprises frequency shifting strips and a defected ground structure (formed by combining of metallic strips and cutting of an L-shaped slot from the ground). The proposed antenna provides three different impedance bandwidths of 0.57, 0.98 and 1.59 GHz which are sufficient to cover the frequency band of GSM 1800/1900, WLAN 5.5/5.8 GHz and WiMAX applications. The developed antenna has a size of 17-20 mm and operates over frequency ranges 1.50–2.08, 5.25–6.23 and 9.10–10.69 GHz centered at 1.702, 5.802 and 10.102 GHz, respectively. The antenna was designed and simulated using Ansoft HFSS software. The antenna’s characteristics such as reflection coefficient, radiation pattern, impedance bandwidth and VSWR are presented.
TL;DR: A detailed scenario of CAD and Digital Human Modeling (DHM) applications in agricultural sector; and finding out means for wide adoption of these technologies for design and development of cost-effective, user-friendly, efficient and safe agricultural tools/equipment and operator's workplace as mentioned in this paper.
Abstract: Computer-aided Design (CAD) and Digital Human Modeling (DHM) (specialized CAD software for virtual human representation) technologies endow unique opportunities to incorporate human factors pro-actively in design development. Challenges of enhancing agricultural productivity through improvement of agricultural tools/machineries and better human–machine compatibility can be ensured by adoption of these modern technologies. Objectives of present work are to provide the detailed scenario of CAD and DHM applications in agricultural sector; and finding out means for wide adoption of these technologies for design and development of cost-effective, user-friendly, efficient and safe agricultural tools/equipment and operator’s workplace. Extensive literature review has been conducted for systematic segregation and representation of available information towards drawing inferences. Although applications of various CAD software have momentum in agricultural research particularly for design and manufacturing of agricultural equipment/machinery, use of DHM is still at its infancy in this sector. Current review discusses about reasons of less adoption of these technologies in agricultural sector and steps to be taken for their wide adoption. It also suggests possible future research directions to come up with better ergonomic design strategies for improvement of agricultural equipment/machines and workstations through application of CAD and DHM.
TL;DR: In this article, variable gap maintaining behavior is modeled using the concept of cellular automata, with the help of a modified cell structure, and the results obtained from the model incorporated with the variable gap-maintaining behavior are significantly different from that of the uniform-cell-width based CA model.
21 Jun 2016
TL;DR: Differences in anthropometric data within and between countries indicate that simple adoption of agricultural tools and equipment from specific regions might lead to occupational health hazards in the target population.
Abstract: OCCUPATIONAL APPLICATIONS Integrated applications of ergonomics and human factors are crucial for designers of agricultural tools and equipment, to improve performance and to enhance safety and productivity. Tools and equipment that do not fit properly with a user's physical characteristics can cause discomfort and fatigue, and may result in low productivity and a higher incidence of accidents/injuries. For workers in the northeastern region of India, it is often not possible to manufacture or adapt user-compatible tools and equipment due to the limited availability of anthropometric and biomechanical data. The anthropometric database developed here is intended to address this lack of information and to assist in the development of anthropometrically compatible tools and equipment for the Assamese population (residents of “Assam,” a state from the northeast region of India). Statistical analyses (principal component and regression analysis) are also reported to help in identifying key anthropometric chara...
TL;DR: In this article, the molecular polarization, order parameter, and dielectric study of a dimeric liquid crystalline compound 7.O5O.7 is reported, and an electrical equivalent circuit model was designed to fit the experimental results.
TL;DR: In this paper, blue-green light emitting undoped and europium doped indium oxide nanocrystal were synthesized by simple precipitation method and the results of photoluminescence (PL) analysis of the samples is the core of the present research.
TL;DR: In this paper, the authors introduced the concept of G-g-contraction mapping and proved coupled coincidence and coupled common fixed point theorems for nonlinear contraction mappings in the new set up of partially ordered complete metric spaces endowed with a directed graph.
Abstract: In this paper, our aim is to introduce the concept of G-g-contraction mapping and prove some coupled coincidence and coupled common fixed point theorems for nonlinear contraction mappings in the new set up of partially ordered complete metric spaces endowed with a directed graph. As an application, we apply our results to present an existence theorem for solution of some particular integral equations. Our paper is inspired by the work of Chifu and Petrusel (Fixed Point Theory Appl. 2014:151, 2014); the authors introduced the concept of a coupled fixed point. In the current paper, however, we have established the results by introducing the new notion of a coupled coincidence fixed point instead of the coupled fixed point in the setting of a partially ordered complete metric space with graph.