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ThesisItem Open Access Impact of surfactant modified ferrite nanoparticles on mechanical and thermal characteristics of epoxy(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-09) Singh, Ashtosh Kumar; Saxena, RakeshPresent investigation deals with development of surfactant modified ferrite nanoparticles (FNs) to achieve the epoxy ferrite composites (EFCs) bearing enhanced dispersion and compatibility of filler with epoxy matrix. This has afforded a series of EFCs with improved tensile, bending, compressive and impact strength. EFCs has shown improved hardness with characteristic reduction in their wear loss. However, a marginal increase in thermal stability of EFCs has been observed. Formation of surface modified FNs (SFNs) and their compatibility with epoxy matrix was clearly revealed through Fourier transformed infra- red spectra. Diversified microscopic methods in combination with X-ray diffraction spectra, magnetometry and DC conductivity experiments reveals enhanced dispersion of SFNs into EFCs. The overall experimental outcome reveals that SFNs (2 phr) imparts improved dispersion, compatibility with epoxy matrix that leads to the formation of EFCs with improved mechanical properties and controlled wear loss. Study further reveals that, EFCs developed through SFNs were of improved durability over those derived from FNs under identical filler loadings. Study finally disclose the importance of surfactants as modifiers for magnetically active fillers such as ferrites and their similar analogues making them suitable for development of high performance polymer nanocomposites suitable for the appliances useful for transportation, stealth and energy management, and biomedical applications.ThesisItem Open Access Effect of stress ratio on fatigue crack growth behaviour of friction stir welding between AA6061 and AA7075 alloys(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-09) Kandwal, Abhishek; Gope, P.C.In the present work, fatigue crack growth in friction stir welded dissimilar AA6061 and AA7075 is performed under different stress ratio and maximum load condition. Crack is a damage that often occurs in members of structures and may cause sudden serious failure of the structures. In a structure generally weld is the weakest section and therefore more prone to failure due to crack propagation. Therefore the study of mechanism of crack growth and its parameters is of paramount importance. The effects of presence of crack on fracture parameters like crack opening stress (Sop) and stress intensity factor (K) of specimen has been the subject of various investigations. However, the parametric studies like effect of stress ratio and amplitude; on the fracture parameters of specimen for friction stir welded joints has gaps in the literature and therefore needs further investigation. Aluminium alloys AA6061 and AA7075 have been chosen for the present study as they are both used in conjunction in many areas of engineering such as marine and aircraft structures. The crack growth rate data for the weld shows that with the increase in stress ratio, fatigue life of the joint decreases. The fatigue life obtained for constant maximum load and varying stress ratio condition shows that the highest Fatigue life is obtained for stress ratio R= -0.5 (48200 cycles) and lowest for R=0.8 (22200 cycles). The curve obtained using Newman equations is closer to plain strain condition. For the constant stress ratio and varying maximum load, it was observed that the fatigue life of joint decreases with the increase in applied maximum load (Pmax) with the highest fatigue life observed for Pmax=4kN (28908 cycles) and lowest for Pmax=6kN (21635 cycles).ThesisItem Open Access Effects of randomly oriented secondary cracks on the fracture parameters in a rectangular plate under static loading(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-08) Ansari, Gulfam Akhtar; Bisht, NeerajIn the present work, a numerical study using finite element is performed to investigate the effects of randomly oriented secondary cracks on the fracture parameters in a rectangular plate under static loading. Crack is damage that often occurs in members of structures and may cause the sudden serious failure of the structures. The effects of the presence of crack on fracture parameters like stress intensity factor and T-stress of specimen has been the subject of various investigations. However, the parametric studies like the effect of crack offset distance, crack size, orientation and number of crack present on the fracture parameters of the specimen are scarce in the literature. The finite element software ANSYS is used to simulate the fracture parameters. Numbers of studies were conducted to study the accuracy of ANSYS and the meshing parameters on which the accuracy depends. Two types of crack geometries were considered viz. parallel cracks and inclined cracks with different crack ratios. Also, the effect of several secondary cracks was studied. The presence of secondary cracks induced a shielding effect on the primary crack. The presence of secondary crack results in the development of mode II SIF. The mode mixing, however, was minimal and the mode II SIF was insignificant compared to mode I SIF. It is observed that when the cracks are closer to each other the shielding effect is high and as the cracks move away the shielding effect decreases. With the increase in inclination angle intensification effect is decreases. The shielding was also higher for a greater number of neighbouring cracks. Higher length of secondary cracks also increased the shielding effect. A correlation between SIF and T stress was also developed and it was seen that they are highly correlated. T stress can also be an important alternative fracture parameter to study crack interaction problems. Statistical analysis was performed to study the impact of various parameters in comparison to each other for all the geometries it was seen that the crack offset distance has a major influence on SIF compared to the crack ratios. Also, inclined cracks were seen to have a profound impact on SIF compared to parallel cracks. Multi-site damage is a common occurrence in aircraft and nuclear industries and the results of the study can contribute to accessing the structural integrity of the structure and estimate the in-service life of the component.ThesisItem Open Access Study of Energy Balance of Sugarcane (Saccharum Officinarum L.) using Remote Sensing and Crop Simulation model in Tarai region of Uttarakhand(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-09) Sharma, Neha; Nain, A.S.The present study was conducted at the Norman E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar to Study the energy balance of sugarcane using surface energy balance algorithm and CANEGRO model during 2015 and 2016. The sugarcane variety selected for the study was Co-Pant 5224. The performance of the CANEGRO model was reasonably well when compared with the observed crop parameters like Leaf Area Index, fresh cane yield (t/ha), Dry weight Yield of Cane (t/ha) etc. during the period of study. Predicted values through CANEGRO model were very close to the observed values in the experimental year. The model performance was tested on statistical ground on the basis of Index of agreement (d) and RMSE (%). The d value for the analysis was 0.86 and RMSE (%) was 17.28 %, which shows that there was limited error in the predicted values as compared to the observed values. The model was found to be more sensitive to the effect of temperature either decreasing or increasing it than mean temperature, CO2 concentration and Irrigation amount (mm) and Radiation (MJ/m2/day). Calibrated CANEGRO simulation model was also used to analyze the impact of climate change on growth and development parameters of Sugarcane. Leaf Area Index, dry weight yield of cane (kg/ha) and time taken for emergence were found to decrease in the future climatic scenarios (2030-2090). SEBAL is a surface energy balance algorithm predicting evapotranspiration using remote sensing technique. It calculates ET through a series of procedures that generates residual energy flux as precursor of ET. In this study, LANDSAT-8 (OLI+TIRS) satellite images for the crop period (2015-16 and 2016-17) have been utilized for extraction of various components of SEBAL in sugarcane crop. The parameters required for SEBAL procedure includes surface albedo, emmissivity, land surface temperature (LST), NDVI, LAI, Vegetative Fraction, momentum roughness length, canopy height, and elevation represented by SRTM-1 arc sec (DEM). The Daily ET computed through SEBAL was later validated by DSSAT computed ET. The results revealed the mean bias error (MBE) of 0.62 mm/day for SEBAL, and R2 of 0.702, represents a higher similarity between the remotely sensed and model estimated evapotranspiration values.ThesisItem Open Access Prevalence, oxidative stress and phyto-therapeutic management of subclinical mastitis with special reference to Staphylococcus aureus in buffaloes(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-12) Tyagi, Arpit; Rajora, V.S.The present study was undertaken to investigate the epidemiology and to determine level of oxidative stress in dairy buffaloes suffering from subclinical mastitis with emphasis on Staphylococcus aureus infection, followed by evaluation of herbal antimicrobial therapy and to compare it with standard antimicrobial therapy based upon antimicrobial sensitivity testing. The overall prevalence of subclinical mastitis recorded in and around Pantnagar was 19.48%. The highest occurrence of subclinical mastitis was observed in high producing 4th to 6th parity buffaloes in their early stage of lactation with more predispositions towards hind-quarters. Staphylococci followed by Streptococci were found to be a major etiological agent. The overall antibiogram of the major bacterial isolates revealed the highest sensitivity to enrofloxacin. PCR assay targeting DNA sequence encoding for 23S rRNA of Staphylococcus aureus was found highly sensitive in rapid identification of S. aureus directly from milk samples as compared to milk culture. There was significant increase in levels of LPO, SOD, CAT, LDH and ALP while significant reduction in GSH was observed in buffaloes with SCM. No significant difference was observed in BUN concentration in buffaloes with SCM which suggests that there was prolonged infection by gram positive bacteria. Micromineral estimation revealed higher serum zinc and iron levels and non-significant increase in serum copper level in buffaloes with subclinical mastitis than that of healthy control. Therapeutic trial revealed the highest efficacy of intramammary infusion of enrofloxacin, followed by Trisama extracts in management of subclinical mastitis in buffaloes which needs further validation through large scale clinical trials.ThesisItem Open Access Investigation of thermal characteristic behavior of rotating packed bed using air-water system(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-10) Saurabh; Murthy, D.S.The investigation of thermal characteristic behavior of rotating packed bed has been conducted in a three-tire approach. Initial testing for the feasibility of thermal responses in the device upon varying the mass flow rate and inlet temperature respectively gave the way for next level of investigation. Here in, the fluid’s mass flow rate ratio, fluid’s inlet temperature ratio, packing rotation and porosity were identified as input/ independent parameters; whereas, pressure drop across the packing, water temperature drop, and heat transfer rate are scheduled as the response variables. The computational fluid dynamics approach has been opted for the entire purpose as it proves beneficial in providing data pertaining to intricate locations that would otherwise have not been possible using conventional methods alone. The implementation of central composite rotatable design scheme has been made in order to obtain corresponding range of data for the analysis of independent parameters.Statistical interpretation of the data for significance of effects caused by the independent variables on to the thermal response variables has been discussed. The use of response surface methodology to discern the thermal behavior of rotating packed bed using surface contours has also been attempted. The vivid discussion of main effects and interaction effects plot is elaborately presented. The use of rotating packed bed secures an overall increment of 157% in the value of heat transfer coefficient for approximately the same temperature drop (~8 K) along with the volumetric reduction in packing/ fills, as high as upto 96.5%.These results justify not only the thermal process intensification in rotating packed bed, but also render sufficient encouragement for futuristic use of this device in the domain of heat transfer applications.ThesisItem Open Access Functional validation of the potential EcCAM, EcCAX1 and EcCAX 3 genes in grain calcium accumulation through over-expression studies in Arabidopsis thaliana: Development of an efficient plant regeneration protocol towards calcium biofortification in finger millet(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-02) Jamra, Gautam; Anil KumarMineral malnutrition is one of the major problems crippling by one-half world population mostly women’s and pre-schooled children. Calcium deficiency is also considered as major problem which may lead to defects in bones, teeth, and osteoporosis. Finger millet (Eleusine coracana) is an orphan crop, rich in calcium with high nutritional significance and antioxidant properties to grow under harsh drought conditions. Multi-pronged molecular approaches were used in our Lab to identify the candidate genes of calcium sensor and transporter families associated with differential grain calcium in different genotypes due to induction of differential calcium signaling and transport machinery. The identified genes were functionally validated in the present investigation through over-expression studies in a model plant of Arabidopsis thaliana. Complete CDS of EcCAM, EcCAX1 and EcCAX3 genes were retrieved from transcriptomic data of pooled spikes of high calcium containing genotype; GP-45. In-silico molecular characterization of these genes based on protein sequences showed the presence of conserved domains as characteristic features. The phylogenetic analysis showed the genes are closely related to Siteria italic and Oryza sativa while distinctly related with Arabidopsis. To decipher the function of EcCaM, EcCAX1 and EcCAX3 genes, the gain-offunction approach was used to generate the transformed lines in Arabidopsis thaliana and expression analysis by semi-quantitative RT-PCR of such genes carried out in T3 homozygous transgenic lines showed higher expression as compared to no expression in wild type. Phenotypic assays were performed under various abiotic conditions such as EcCAM under PEG induced drought stress, IAA induced homeostasis, NaCl induced salt stress and calcium induced ionic stress; EcCAX1 and EcCAX3 under calcium & magnesium ionic stress, and IAA induced homeostasis. The observations recorded in 7 days old seedlings suggested that over-expressed transgenic lines were more tolerant as compared to wild type as evident from root elongation with lateral growth and better physiology. The anti-oxidative potential of over-expressed transgenic lines was higher in transgenic lines showing less ROS accumulation while more ROS accumulation in wild type plants as indicated by NBT and DAB staining method. Thus, more oxidative damage was observed in wild type as compared to over-expressed transgenic lines. Finger millet is highly adaptive in harsh conditions and nutritionally superior necessitate its further improvement using transgenic technology. In order to develop superior genetically modified plants, an efficient plant tissue culture protocol is essentially required taking innate nutritional, biochemical and hormonal attributes of finger millet genotypes as indices of plant tissue culture responsiveness. In order to determine the influence of stress tolerant behavior and inherent composition on plant regeneration, four genotypes of finger millet (GP-45, GP-1 GE-1437 and GE-3385) were taken in the present study. The results indicate that GP-45 was found to show maximum stress tolerance whereas GP-1 was the least tolerant. Further estimation of endogenous total calcium, carbohydrates, protein, total phenols, total flavonoids and phytohormones (ABA and GA3) showed genotype dependent variations and high calcium is related with stress tolerance and in turn plant tissue culture responsiveness. The results of the present study clearly elucidate the importance of selection of genotypes based on biochemical indices such as innate phytonutrients, phytochemicals and phytohormones for the development of an efficient regeneration protocol in finger millet to introgres the potential genes whose functions validated through genetic transformation studies in Arabidopsis could further be harnessed for crop improvement especially for improving calcium nutrition and stress tolerance.ThesisItem Open Access Characterization and QTL mapping of Teosinte derived maize population for BLSB resistance and other traits(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-08) Adhikari, Sneha; Singh, N.K.The investigation was carried out with the aim to map genomic region for resistance to banded leaf and sheath blight and other traits. The field experiments were conducted during rabi 2016-2017, kharif 2017, rabi 2017-18 for development of mapping population while kharif 2018 season was used for phenotyping of BC1F5 mapping population under artificially inoculated with Rhizoctonia solani and control conditions. Among BC1F3 and BC1F4 generation of teosinte derived maize population, large phenotypic variation was observed for all morphological traits, hence teosinte can be used for enhancing maize germplasm. Of the 126 lines 76, 20 and 21 lines were of protogynous behaviour, short ASI (0-1 days) and bears > 3 ears per plant, respectively in both BC1F3 and BC1F4 generations. Jaccard similarity coefficients and dendrogram generated using SSR markers data indicate 25 percent genetic similarity in maize and teosinte. Analysis of variance showed highly significant variation among the BC1F5 lines for disease reactions and other traits. Among 169 BC1F5 lines, 9 (MT-25, MT-90, MT-99, MT-128, MT-136, MT-144, MT-145, MT-148, MT-152) comes under the category of moderately resistant class and can be utilize in maize BLSB resistance breeding. Analysis of variance (ANOVA) revealed significant variance between the environment for days to anthesis and silking, anthesis-silking interval (ASI), flag leaf length, flag leaf width, ear per plant, ear length, ear diameter, kernel rows per ear, kernels per row, test weight and grain yield per plant. It indicates greater impact of disease stress on these characters. Correlation analysis exhibited significant correlation of BLSB resistance with flag leaf angle, plant height, ear length, ear diameter, kernel rows per ear, kernels per row, test weight and grain yield per plant. The single-marker ANOVA revealed a total 125 QTLs, of these 4 were major and 121 were minor QTLs for 14 traits. These QTLs were distributed over 10 chromosomes with phenotypic variation ranges from 2.29 to 12.98 per cent. Out of 125 QTLs, 64 and 61 QTLs were detected in E1 and E2, respectively and of which 20 QTLs were common in both the environments. Maximum QTLs were detected in chromosomes 4 and 9 followed by 7, 6, 10, 5, 2, 1, 3 and 8. Consistent QTLs across the environments were identified for days to anthesis (3), days to silking (2), flag leaf length (1), flag leaf width (1), plant height (2), ears per plant (1), node bearing first ear (2), ear length (2), ear diameter (1), kernel rows per ear (3), test weight (1) and grain yield per plant (1). The single-marker ANOVA analysis revealed one major QTL on chromosome 5 and four minor on chromosomes 1, 3, 4 and 8 for BLSB resistance under DE1. In DE2 however only four minor QTLs one each on chromosomes 1, 3, 5 and 8 were identified. Out of these nine QTLs two were identified across the environments that were linked with markers umc1500 and phi10918, considered as stable QTLs. Among seven identified QTLs for BLSB resistance, a major QTL linked with phi10918 was colocalized with three minor QTLs for ear length, kernel rows per ear and kernels per row. Seven minor QTLs for days to anthesis, days to silking, ear length, ear diameter, kernel rows per ear, kernels per row and grain yield per plant were co-localized with a minor QTL for BLSB resistance that linked with marker umc1720. One minor QTL for BLSB resistance that was linked with phi420701 was collocated with a major QTL for plant height. Remaining two minor QTLs for BLSB resistance namely, umc1500-linked QTL and umc2000-linked QTL were colocalized with QTL for test weight and ear per plant, respectively. The investigation successfully identified lines with desirable traits that can be utilized in stress resistance breeding. Co-localized QTLs identified for various morphological traits and disease resistance can integrate/pyramid in breeding materials for improving BLSB resistance.ThesisItem Open Access Response of kharif maize (Zea mays L.) to differential placement of fertilizer doses and potassium splitting(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-07) Pandey, Deepak; Bhatnagar, AmitA field experiment was conducted during the kharif season 2016 and 2017 at the Norman E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar to examine the effect of differential fertilizer placement, potassium splitting and nutrient doses on maize. The experiment consisting of two K split (100% as basal and 50% as basal + 50% at earthing up), eight nutrient doses (75-75-75, 75-75-100,75-100-75, 75-100-100, 100-75-75,100-75-100, 100-100-75 and 100-100-100 per cent of recommended NPK) under differential fertilizer placement depths (50% fertilizers at 10-12 cm and 50% in furrows at 5 cm depth) along with a farmers’ practice treatment (100% recommended NPK dose and furrow application of fertilizers at 5 cm with whole K as basal) was laid out in factorial randomized block design with three replications. The recommended dose of nutrients was 150:60:40 kg N:P2O5:K2O/ha. Planting geometry was 75 cm × 20 cm and crop was grown as per recommended practices. The soil of the experiment site was silty clay loam in texture having medium organic carbon (0.71%), low available nitrogen (234.9 kg/ha) and medium available P (20.7 kg/ha) and K (212.4 kg/ha) contents with neutral pH (7.2). Split application of K had significant impact on growth parameters, yield attributes and yield over its 100% basal application. It resulted in 6.1 and 4.7 per cent increase in grain yield over 100% basal application during 2016 and 2017, respectively. Application of K in splits also fetched higher gross return, net return and B:C ratio than its basal application. Application of 100% NPK being on par with all the nutrient doses in which 100% N was used with either 75 or 100% P and K, produced significantly more growth parameters and yields than the lower doses. Average increment in grain and stover yields under 100% NPK dose was 40.6 and 33.1, respectively over 75% NPK. Economics of cultivation viz. gross return, net return and B:C ratio were also found significantly higher under 100% recommended NPK dose which was at par with 100% N +75% PK, 100% NK+ 75% P and 100% NP+ 75% K. Crop performance in terms of growth, yield attributes and yield was also found significantly higher under differential fertilizer placement with and without K split application than farmers’ practice. Research findings of this study revealed that splitting of potassium in two equal parts i.e. 50% basal and 50% at earthing up in kharif maize is the better option against its whole application in basal in terms of productivity, profitability and nutrient use efficiency under silty clay loam soils of Pantnagar. Differential placement of fertilizers (50% in root zone at 10-12 cm and 50% in seed zone in furrows at 5 cm) can help in saving of 25% recommend dose of P and K.
