Thumbnail Image

Thesis

Browse

2019 - 201912020 - 20212
Reset filters
Author: Jasleen Kaur × Start date: 2018 × Type: Thesis ×
Reset filters

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    ThesisItemRestricted
    Characterization and evaluation of rice straw lignin phenolics on pollen germination in pumpkin
    (Punjab Agricultural University, Ludhiana, 2021) Jasleen Kaur; Ramandeep Kaur
    Rice straw is one of the most abundant, renewable, cost-effective and non-edible agricultural feedstocks. Its burning has led to air pollution, loss of soil fertility and nutrient depletion, therefore valorization of rice straw is important. Straw was found to be chemically composed of 24% hemicellulose, 41% cellulose, 9% lignin, 20% extractives and 6% ash (silica). Lignin was extracted using dilute acid pretreatment (1% H2SO4) followed by alkaline hydrolysis using NaOH. FT-IR, 1H and 13C NMR were used for structural characterization of the lignin obtained from rice straw. The ethyl acetate extract of acid solubilized lignin was found to contain p-coumaric acid, ferulic acid and caffeic acid as the major phenolic acids which were isolated using preparative thin layer chromatography. The phenolic acids were characterized using elemental analyses, FT-IR, 1H and 13C NMR spectroscopy. Amides of p-coumaric acid, ferulic acid and caffeic acid were synthesized by their reaction with propyl and butyl amines using microwave irradiation and analysed using spectral studies. Phenolic acids and their amides were evaluated for their effect on pollen germination and tube growth in pumpkin. It was concluded that at 5 ppm concentration, germination percentage and pollen tube growth of p-coumaric acid, caffeic acid and their amides was enhanced than the control. These results could be utilised in increasing pollen tube length of Cucurbita moschata while making interspecific cross between C. moschata and C. pepo in order to transfer the hull-less and disease and virus resistant character of C. moschata to C. pepo.
  • Thumbnail Image
    ThesisItemRestricted
    Dissipation kinetics of halosulfuron-methyl and its effect on soil enzymes
    (Punjab Agricultural University, Ludhiana, 2021) Jasleen Kaur; Pervinder Kaur
    The present study investigate the degradation dynamics of halosulfuron-methyl in soils under laboratory conditions. Soil samples were treated with halosulfuron-methyl at application rates of 67.5, 135, 202.5 and 270 g ha-1. Soil type, application rate and temperature had a great influence on degradation rate of halosulfuron-methyl. Halosulfuron-methyl residues were extracted by ultrasonic assisted extraction (UAE) and matrix solid phase dispersion (MSPD) and quantified using HPLC-UV. The mean percentage recoveries obtained using UAE and MSPD varied from 88.33±5.44 to 99.43±4.22% and 85.70±4.98 to 97.37±3.50% with limit of detection (LOD) and limit of quantification (LOQ) as 0.0026 µg mL-1 and 0.008 µg mL-1, respectively. Dissipation of halosulfuron-methyl followed first order kinetics with half- lives varying from 9.38 to 33.77 days. Degradation increased with increase in temperature and varied from 14.39 to 33.77, 11.05 to 28.94 and 9.38 to 25.41 days at 5±2, 15±2 and 25±2°C. Halosulfuron-methyl had a transitory effect on dehydrogenase, alkaline phosphatase, acid phosphatase activity and soil microbial biomass (bacteria, fungi, actinomycetes and phosphate solubilizing bacteria population) but urease activity remains unaffected.
  • Thumbnail Image
    ThesisItemRestricted
    Interrelationship between electrical conductivity, refractive index and viscosity of honey
    (Punjab Agricultural University, Ludhiana, 2019) Jasleen Kaur; Paramjit Singh
    The present work has been undertaken to make a systematic study of the physicochemical parameters of raw honey like electrical conductivity, refractive index and viscosity to establish an interrelationship between them. This interrelationship will help to determine the refractive index and viscosity from electrical conductivity values of honey. All the measurements were taken at different temperatures (20, 30, 40, 50, 60, 70˚C) and concentrations (100, 90, 80, 70, 60 and 50%). The electrical conductivity increased linearly both with temperature and upon dilution. The refractive index decreased linearly with temperature and was found to increase linearly with concentration of honey. The viscosity of honey decreased exponentially both with the increase of temperature and with decrease of concentration. The Arrhenius mathematical model was applied to establish the temperature dependence of honey viscosity and thus used for the determination of its activation energy. The honey with highest viscosity values displayed the highest value for activation energy. The temperature-coefficient of refractive index (thermo-optic coefficient) was found to be same for all the concentrations. The data obtained were statistically analysed using one-way analysis of variance (ANOVA) at 5% level of significance. The studied parameters were found to vary significantly with temperature for all honey concentrations. The equations modelling the relationship of electrical conductivity with viscosity and refractive index values of honey were obtained. The regression equations were found to have high correlation coefficients (> 0.93).