Loading...
Thesis
Browse
43 results
Search Results
ThesisItem Open Access Adsorption and desorption characteristics of imazamox in soils of Punjab(Punjab Agricultural University, Ludhiana, 2018) Saini, Amita; Pervinder KaurThe adsorption-desorption behaviour of imazamox in three Punjab soils was evaluated using the batch equilibrium technique. The adsorption- desorption kinetics of imazamox were found to be a two step processand was well described by pseudo second order kinetic model. On the basis of the measured R2 values, the adsorption data fitted well in Freundlich model (R2> 0.998) followed by Langmuir (R2>0.981) followed by Temkin (R2>0.870) and D-R (R2>0.447). KFads ranged from 1.358 to 2.148 μg1−1/n g−1ml1/n indicating that imazamox has weak adsorption capacity that varied significantly with the concentration, temperature and properties of soil. KFdes was found to be higher as compared to KFads for the studied soils. Desorption of imazamox was hysteretic in all the studied soils and hysteresis coefficient varied from 0.001 to 0.015. Thermodynamic analysis showed that imazamox adsorption onto soils was a feasible, spontaneous and exothermic process which becomes more favourable at low temperature.ThesisItem Open Access Synthesis and characterization of zinc sulfide (zns) nano aqua-emulsions for their antifungal evaluation against phytopathogenic fungi(Punjab Agricultural University, Ludhiana, 2018) Navdeep Kaur; AnjaliZinc sulfide nanoparticles in aqua-dispersed form were prepared by reaction of zinc acetate with sodium sulfide by sonochemical method. Zinc ion and sulfide ion coated ZnS nanoparticles were prepared in different molar ratios of ion to ZnS nanoparticles. The products were characterized by Transmission Electron Microscopy (TEM), UV-Visible spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). All the synthesized samples of zinc sulfide nanoparticles were screened for their in vitro antifungal potential against various phytopathogenic fungi viz. C. capsici, P. drechsleri, P. cubensisand P. parasiticaby applying spore germination inhibition technique, using Copper Oxychloride and Metalaxyl-M + Mancozebas a standard for comparison of the results. The prepared samples exhibited excellent broad spectrum inhibitory activity against all the test fungi, at concentration as low as 5μg/ml, which was multifold lower than the standards used. ZnS:Zn+2(1:5) exhibited better results among all samples.ThesisItem Open Access Chemistry and antimycotic potential of mentha based shellac coatings against penicillium digitatum of kinnow fruit(Punjab Agricultural University, Ludhiana, 2018) Harpreet Kaur; Tandon, RituThe present study deals with chemistry and antimycotic potential of Mentha based shellac coatings against Penicillium digitatum of kinnow fruit. Essential oil (EO) of two species of Mentha viz. Mentha piperita and Mentha arvensis was extracted using Clevenger-type apparatus. Per cent yield of essential oil of M. arvensis (2.8%) was found higher than M. piperita (2.1%) Compositional analysis of M. piperita essential oil by GC-MS revealed presence of 51 compounds. M. piperita EO exhibited better antimycotic potential than M. arvensis EO against P. digitatum. Hence, Process of nanoemulsion (NE) development of M. piperita EO was optimized for parameters such as oil and surfactant ratio (v/v) with three sonication times (ST) with the help of probe ultrasonicator. Effect of surfactant concentration and sonication time on droplet diameter and electrical conductivity was studied. Nanoemulsion of 1:0.5 ratio of oil and surfactant with 20 min ST exhibited smallest droplet diameter as well as maximum stability at refrigerator temperature (4°C) than ambient temperature (25°C) over the storage period of 2 months. M. piperita based shellac nanoemulsions were prepared for the best.1:0.5 (v/v) oil and surfactant ratio. NE with 15 minute ST showed more effective inhibition (96.0%) against P. digitatum in comparison to other nanoemulsions as well as pure M. piperita EO (71.0%). Optical and SEM results showed morphological changes in treated fungus. Nanoshellac coating showed maximum inhibition at par with the standard Carbendazim.ThesisItem Open Access Structural and magnetic properties of ferric oxide-silica core-shell nanocomposite and its application for removal of cd (ii) ion(2018) Jaskirat Kaur; Manpreet KaurStructural and magnetic properties of ferric oxide-silica core-shell nanocomposites were investigated for facile removal of Cd(II) ions from water. Silica (SiO2), ferric oxide (Fe2O3) nanoparticles, Fe2O3@SiO2 and SiO2@Fe2O3 coreshell nanocomposites were synthesized by modified Stober’s method, co-precipitation method, surfactant assisted sonication method and surfacant assisted direct precipitation of SiO2 on the surface of Fe2O3 NPs respectively. Techniques viz. X-ray diffractiion pattern (XRD), Vibrating sample magnetometer (VSM), Brunauer-Emmett-Teller (BET), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), and FT-IR spectroscopy were invastigated. The effect of different reaction parameters including adsorbent dose, temperature, contact time, pH, initial metal ion concentration of Cd(II) was studied. Optimum pH for adsorption was 6. With the increase of temperature, the removal efficiency of synthesized adsorbents for Cd(II) ions increased up to 55ºC and then decreased. Values of ΔGo found to be negative for all the adsorbents, indicating spontaneous nature of adsorption process. While, positive values of ΔH and ΔS for all adsorbents indicated the endothermic nature of adsorption process. The trend for the percentage removal of Cd(II) in the descending order was Fe2O3@SiO2 > Fe2O3 > SiO2@Fe2O3 > SiO2. The trend for the fitting of adsorption isotherms in descending order was Freundlich > Langmuir > Tempkin > D-R isotherms. The adsorption followed pseudo second order kinetics. The advantage of nanocomposites is enhancement of adsorption potential due to presence of Fe2O3 along with SiO2. The results signified that core-shell reversal is effective way of tailoring the properties of nanocomposites.ThesisItem Open Access Synthesis of nicotinic acid derivatives and their evaluation against root knot nematode(Punjab Agricultural University, Ludhiana, 2018) Jain, Nisha; Utreja, DivyaSeven amide derivatives of nicotinic acid were synthesized by condensation reaction of nicotinic acid adsorbed on silica gel with different aromatic amines. The characterization of synthesized derivatives was done using 1H NMR, 13C NMR and IR spectroscopy. The resulted compounds were also screened for their nematicidal activity against root knot nematode Meloidogyne incognita by egg hatching and mortality test. All the compounds exhibited significant nematicidal potential as compared to control. Maximum egg hatching inhibition potential was exhibited by N-(4-bromophenyl)nicotinamide while N-(2,4,5-trichlorophenyl)nicotinamide showed maximum mortality potential.ThesisItem Open Access Synthesis of novel 1,2,4-triazolosulfonamides as antifungal agents against phytopathogenic fungi(Punjab Agricultural University, Ludhiana, 2018) Lovepreet Kaur; AnajliA series of 1,2,4-triazolosulfonamides was synthesized by microwave irradiation method in excellent yield, using sulfonyl chlorides and 1,2,4-triazoles as starting materials. The products were characterized by FT-IR, 1H NMR, 13C NMR and screened for their antifungal potential against various phytopathogenic fungi viz. Alternaria alternata, Curvularia lunata, and Helminthosporium oryzae by poisoned food technique in terms of ED50 values. The synthesized compounds displayed moderate to significant activity. Among all test compounds, 4-Methyl-N-(1H-1,2,4-triazol-3-yl)benzenesulfonamide (4) and 4-Methyl-N-(4H- 1,2,4-triazol-4-yl)benzenesulfonamide (7) showed best antifungal activity against all test fungi with respective ED50 values 4.0 and 3.4 μg ml-1 against Alternaria alternata, 2.3 and 2.0 μg/ml against Curvularia lunata and 3.5 and 3.0 μg/ml against Helminthosporium oryzae, multifold lower than the standard fungicides used, Tilt and Captan. The results were rationalized on the basis of in silico analysis viz. Toxicity analysis, Docking analysis and Lipinski parameters.ThesisItem Open Access Dissipation kinetics of metribuzin and its effect on soil enzymes(Punjab Agricultural University, Ludhiana, 2018) Geetika Rani; Pervinder KaurThe present investigation was undertaken to study the dissipation kinetics of metribuzin and its effect on soil enzymes. The residues of metribuzin from soil were extracted using matrix solid phase dispersion. Dissipation of metribuzin followed first order kinetics and half life ranged from 15.57 to 45.07 days days in three soils. Physicochemical properties of soil, application rate and temperature have differential influence on dissipation behaviour of metribuzin. Dissipation rate of metribuzin increased with increase in soil organic matter content and temperature. In enzyme assay studies, effect of metribuzin on three soil enzymes viz. dehydrogenase, alkaline phosphatase and urease was investigated. Metribuzin application significantly affected the soil dehydrogenase and alkaline phosphatase activity. However urease activity remained unaffected by application of metribuzin. Soil dehydrogenase, alkaline phosphatase and urease activity were significantly affected by soil type and temperatureThesisItem Open Access Chemistry and antioxidant potential of dill (Anethum graveolens L) seed essential oil(Punjab Agricultural University, Ludhiana, 2018) Navneet Kaur; Chahal, K.K.The present investigation deals with chemistry and antioxidant potential of dill (Anethum graveolens L.) seed essential oil. The dill seed essential oil was analysed using GC–MS which showed the presence of 31 compounds. Carvone (41.15 %) was identified as major compound; other compounds identified were limonene (23%), camphor (9.25%), dihydrocarvone (3.75%), butyl acetate (2.65%), dill apiole (1.65%) and dill ether (1.02%) etc. The essential oil was fractionated into its non-polar and polar fractions by column chromatography. Carvone, limonene and camphor were isolated from dill seed oil using column chromatography. Carvone, limonene and camphor were chemically transformed into different derivatives viz. carveol, carvone semicarbazone, carvone oxime, camphor oxime and perillyl alcohol. Isolated and transformed compounds were identified using FT-IR, 1HNMR and 13CNMR spectroscopy. Methanol, dichloromethane and hexane extracts were prepared by Soxhlet extraction method. Presence of phytochemicals such phenols, flavonoids, anthraquinone, reducing sugar, tannins, cardiac glycosides and saponin were tested in hexane, dichloromethane and methanol extract. Quantitative estimation of phenolic, flavonoid, sugars, peroxide value and saponification value was calculated. Dill seed essential oil, its fractions, isolated and derivatized compounds were tested for their antioxidant potential at different concentration levels viz. 1.0, 0.5, 0.25, 0.1 and 0.05 mg ml-1. The antioxidant potential of tested components were evaluated using 2, 2 diphenyl-1-picrylhydrazyl (DPPH•), hydroxyl (OH•), nitric oxide (NO•), superoxide (O2•) radical scavenging methods and ferric reducing antioxidant power (FRAP) assay. Methanol extract was found most active among extracts and fractions whereas carveol showed maximum potency for radical savenging activity amongst isolated and derivatised compounds.ThesisItem Open Access Synthesis of benzylidene derivatives using green methods and their microbial activity(Punjab Agricultural University, Ludhiana, 2018) Verma, Diksha; Sharma, SunitaSchiff bases are the condensation products of aldehydes and amines. Compounds (I-VII) have been synthesized by reacting 4-amino-1,2,4-triazole with different substituted benzaldehydes i.e. 4-bromobenzaldehyde, 4-nitrobenzaldehyde, furfuraldehyde, cinnamaldehyde, 4-N,N¢- dimehylaminobenzaldehyde, 4-N,N¢-diethylaminobenzaldehyde and 2,5- dimethoxybenzaldehyde using two different acidic catalysts i.e. tamarind extract and glacial acetic acid. These Schiff bases were also synthesized using conventional and microwave irradiation method. Microwave irradiation method proved to be time efficient and economical for the synthesis of Schiff bases. It was also observed that glacial acetic acid was best acid catalyst as compared to tamarind extract in aspects of yield and reaction time as former afford much higher yield and reaction got completed in much shorter time. As the catalytic amount of both the catalyst increased, the yield of corresponding Schiff bases increased. Antimicrobial activity of synthesized compounds against Pseudomonas aeruginosa, Klebsiella sp, and Enterobacter sp. revealed that Compound (II) was most effective with lowest MIC value against Klebsiella sp. None of the compounds was as effective as standard ampicillin. All the synthesized compounds differed significantly among themselves at all the test concentrations.
