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2020 - 20223
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Author: Manpreet Kaur × End date: 2022 × Start date: 2020 × Thesis Type: Ph.D ×
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    Synthesis of boron and phosphorous doped graphene fabricated with magnesium ferrite – bentonite nanocomposite for the remediation of pollutants
    (Punjab Agricultural University, 2022) Manpreet Kaur; Manpreet Kaur
    Graphene oxide (GO) doped with heteroatoms are gaining interest in depollution of water because of their large surface area. The boron-doped GO (B-GO), phosphorous-doped GO (P-GO) and boron and phosphorous co-doped GO (BPGO) in different w:w ratios were synthesized and fully characterized using analytical techniques viz. FT-IR, XRD, SEM-EDS, TEM, BET, Mössbauer and XPS. In order to impart magnetic features to doped GO materials, magnesium ferrite-bentonite (MGF-B) was used to fabricate nanocomposite of MGF-B and BPGO having hierarchical nanoflowers like morphology (HNFs). TEM of co-doped GO showed more wrinkled surface than doped GO, whereas in case of HNFs, chiffon-like BPGO nanosheets were wrapped on the MGF-B surface, resulting in a porous flower-like morphology. The synthesized materials were explored as adsorbents for the removal of Pb(II) and As(III) ions and as photocatalysts for the degradation of martius yellow, p-nitrophenol and malathion from synthetic waste water. The trend for the percentage removal of heavy metals by adsorption and degradation of organic pollutants by photocatalysis in the descending order was found to be: HNFs > BPGO-1:1 > BPGO-1:5 > BPGO-1:0.2 > MGF-B > P-GO > B-GO > GO. The adsorptive and photocatalytic potential of HNFs was greater as compared to pristine, doped and codoped GO due to high surface area, remarkable charge transfer ability and layered structure of codoped GO sheets. The HNFs possessed appreciable saturation magnetization than doped and co-doped GO layers, which led to its easy separation and reusability. Box-Behnken design was utilized for exploring the simultaneous effects of the independent variables on removal of metal ions and degradation of organic pollutants (as dependent variable) using HNFs. The adsorption and photocatalytic mechanism was proposed on the basis of adsorption isotherm, thermodynamic, kinetic and quenching studies. Enhanced activity of HNFs with adsorption of heavy metal could be defined by the electronic structural properties of elements. The best adsorbent and photocatalyst were also tested for spiked solution containing different metal ions and real life industrial water matrices.
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    Mapping and transfer of higher grain length and multiple rust resistance from T.dicoccoides to cultivated wheat
    (Punjab Agricultural University, Ludhiana, 2022) Manpreet Kaur; Satinder Kaur
    Wild emmer wheat, Triticum dicoccoides, the progenitor of modern tetraploid and hexaploid wheats, is an important resource of new variability for disease resistance genes and grain yield traits. T.dicoccoides acc. pau14723 showed resistant to leaf and stripe rust races and was crossed with T.dicoccoides acc. pau4663 (susceptible to leaf and stripe rust) for studying the inheritance and mapping the genes for leaf and stripe rust resistance. Recombinant inbred lines were developed and screened against highly virulent Pt and Pst pathotypes at the seedling and adult plant stages. Inheritance analyses revealed that both the rust infections were controlled by dominant major single gene. For mapping these genes, the markers showing diagnostic polymorphism in the resistant and susceptible bulks were amplified on all RILs. The molecular characterization identified the genes to be present on 1A chromosome of wheat (short arm). MapDisto version 1.7.5. Beta 4 software was used to determining the linkage present between the genes governing resistance and the SSR markers Xbarc148, Xbarc240, Xwmc93, Xwmc818. A total map size of 9.7cM was obtained showing no segregation between Lr and Yr genes and the marker lying closest to the resistance genes was Xbarc148 at 1 cM distance from the resistance genes. The variation in the T. dicoccoides for the yield related traits was studied by crossing the accessions having longer and wider grains with the accessions having shorter grains resulting in three different crosses: T.dico.14723 and T.dico. 4663, T.dico.5219 x T.dico. 4663 and T.dico. TA1027 x T.dico. 5232. The RIL populations developed from these crosses were screened for different traits affecting the yield which include 100 grain wt. (100 Gwt.), spike length (SpL), spike length with awns (SpLWA), no. of spikelets/spike (Splts/Sp), grain length (GL), grain width (GW) and grain area (GA). The interaction between the traits and their contribution to grain yield was studied. The molecular and the phenotypic data was statistically analyzed for the significant contribution of marker alleles. The evaluation of allelic effects of the polymorphic markers for each trait using Kruskal–Wallis test showed that the phenotypic differences in the mean value of GL, GA and GWT were statistically significant for the three different classes of TaGASR7-A and TaGASR7-D. The study suggests the use of variation existing in T.dicoccoides germplasm for wheat breeding programmes.
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    ThesisItemOpen Access
    Processing suitability of chili varieties for value added products
    (Punjab Agricultural University, Ludhiana, 2020) Manpreet Kaur; Sachdev, Poonam A.
    The present investigation entitled ―Processing suitability of chili varieties for value-added products‖ was carried out with the objectives to assess the physicochemical, phytochemical and antioxidant activity of Punjab Sindhuri and CH-27 chili varieties, development of chilli paste with enhanced shelf stability, drying characteristics of chili varieties and preparation of value added products with greater shelf stability and to extract oleoresins by using conventional and non-conventional methods. The CH-27 contained highest total soluble solids (5º Brix), total solids (20.7%), ash content (1.47%), total sugars (4.4mg/100 gm), crude fibre (9.81%), total phenolics (276 mg/100ml), ascorbic acid (132.17 mg/100 gm) and capsaicin (1.17%), while Punjab sindhuri contained highest total chlorophyll (10.43), carotenoids (12.05mg/100 gm), β-carotene (5.85mg/100 gm) and lycopene (3.2µg/100 gm). Among different drying techniques, freeze drying at -40ºC showed significantly highest retention of physicochemical, phytochemical and antioxidant properties in both chili varieties. During 8 months storage (room as well as refrigeration), honey chili sauce containing CH-27 (red) showed utmost retention of total phenolics (679.46mg/100ml), β-carotene (308 mg/100 gm), lycopene (4.59µg/100 gm), per cent inhibition of DPPH (52.02%), FRAP (3.43 mM/100 gm), while honey chili sauce containing Punjab sindhuri (red) significantly retained maximum total solids (84.49%) ascorbic acid (5.54mg/100 gm), color a value (4.84), ash content (2.86%) and total sugars (63.56 gm/100 gm). Red and green form of both chili varieties were processed into the paste and stored at the room as well as refrigeration temperature. The chili paste yield was found significantly higher for Punjab sindhuri (green and red) than CH-27. Treatment containing 0.2gm KMS + 0.2gm sodium benzoate + 1ml acetic acid + 5gm NaCl per 100 gm of chili paste was found to be effective for the better retention of physicochemical, phytochemical and antioxidant activity during 10 months duration of storage. Highest oleoresin yield i.e.7.1% from Punjab sindhuri red variety was observed with ultrasonication method.