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  • ThesisItemOpen Access
    Influence of ohmic heating on electrical properties of tomato puree
    (Punjab Agricultural University, Ludhiana, 2019) Kiranjot Kaur; Paramjit Singh
    Ohmic heating is a green processing technique that is different from other processing methods. In this process electric current is allowed to pass through the food sample and heating occurs due to inherent resistance of sample. It is highly efficient technology and provides rapid and uniform heating. In this study, ohmic heating treatment was applied to different concentrations (100, 90, 80, 70 and 60%) of tomato puree. The puree was ohmically heated from 30 to 70⁰C at four different voltage gradients of 8, 6, 4 and 2V/cm for different concentrations. Measurements have been made on electrical conductivity, ohmic heating rate, density, pH, TSS and specific heat. The voltage gradient and concentration has significant effect on electrical conductivity of tomato puree. Electrical conductivity and ohmic heating increases linearly with rise in temperature, concentration and voltage gradient. pH and TSS are also noted before and after the ohmic heating treatment. Statistical analysis has been conducted and observed that this treatment has no significant effect on pH and TSS values. System performance coefficient was also calculated for ohmic heater at different voltage gradients and observed that as the concentration of tomato puree decreases the efficiency of ohmic heating apparatus shift towards higher voltage gradient in prescribed voltage range.
  • ThesisItemRestricted
    Improved randomised response technique for estimation of sensitive character
    (Punjab Agricultural University, Ludhiana, 2019) Manpreet Kaur; Grewal, Inderjit Singh
    Getting correct answers to sensitive questions from the respondents and estimating the population parameters on variables that are sensitive in nature is still a problem in survey sampling. In the present project work, problem of estimation of population proportion of sensitive characteristic have been studied. For this improved randomized response device has been developed by taking the two cases of unrelated question, case-I „when the unrelated characteristic is known‟ and other case-II „when the unrelated characteristic is not known‟. Two estimators have been proposed one for known value of and other for unknown value of which were found to be unbiased. The expression for variances and unbiased estimates for the variances of the proposed estimators have been obtained. The optimum value of sample sizes have been worked out for which the minimum variance for the proposed estimators have also been obtained. In order to see relative efficiency, the proposed estimators have been compared on the basis of relative efficiency with respect to Tiwari and Mehta (2016) and Mangat (1992). An empirical study have been conducted and concluded graphically that proposed estimators are better than the estimators of Tiwari and Mehta (2016), Mangat (1992).
  • ThesisItemOpen Access
    Estimation of water content in wheat (Triticum aestivum L.) using beta radiations and plant water indices
    (Punjab Agricultural University, Ludhiana, 2019) Akshdeep Kaur; Sharma, Rajeev Kumar
    A field experiment was set up in split-plot design to use beta attenuation technique for estimation of water content (WC) of wheat (Triticum aestivum L.). Wheat cultivar PBW 550 Unnat was grown having two nitrogen contents i.e. 120 kg ha-1 (N1) and 150 kg ha-1 (N2) each under different irrigation regimes viz., irrigation at critical stages (I1), based on IW/CPE ratio of 0.9 (I2) and water stress conditions (I3) that were replicated thrice. 204Tl has been used as radioactive source with 0.766 MeV as end point energy. Logarithmic relative intensity versus thickness curves are plotted for fresh and dry state of wheat leaves for all treatments and mass attenuation coefficient (μm) values are used to evaluate WC. It is observed that μm is more for dry leaves than for fresh leaves. Maximum WC is found in I1 followed by I2 and minimum is in I3 for both nitrogen levels. Also, results of WC using beta attenuation are found in good agreement with direct weighing method and comparable with relative leaf water content. Stress degree days is evaluated and found minimum for N2I2 treatment. Also, the highest grain yield is obtained for N2I2 treatment. Study revealed that increasing N content can reduce stress due to more temperature and less irrigation. Considering the results, it can be inferred that N2I2 treatment would be best management intervention for wheat cultivation. Beta attenuation technique is found useful for estimation of WC and can effectively be used in irrigation scheduling for saving of water.
  • ThesisItemOpen Access
    Gardner solitons in Electron-Positron-Ion plasma featuring Cairns-Tsallis electrons
    (Punjab Agricultural University, Ludhiana, 2019) Manpreet Kaur; Parveen Bala
    Solitary waves are nonlinear and localized structures which arise when there is balance between nonlinearity and dispersion. In the present study, the effects of non-thermal and non-extensive distribution of electrons on the soliton propagation in plasma system containing Boltzmann positrons have been studied. The given distribution is applicable to this study to a limited range of values of q and α, 0.6< q≤ 1 and 0≤ α< 0.25. Using Reductive Perturbation method, Korteweg-de Vries (K-dV), modified K-dV (mK-dV) and Gardner equations are derived for electron-positron-ion (e-p-i) plasma system. The soliton solution of the Gardner equation is discussed in detail. Results have been interpreted in the form of graphs. It is found that for a given set of parameter values, there exists a critical value of q (i.e, qc) below which only rarefactive K-dV solitons exist and above it compressive K-dV solitons exist. However, at the critical value of q, both compressive and rarefactive mK-dV solitons co-exist. In this region, for q > qc, rarefactive Gardner solitons and for q < qc, compressive Gardner solitons are found. The present investigation may help us to understand the electrostatic perturbations in laboratory and space plasmas.
  • ThesisItemRestricted
    Carbon Based Quantum Dots: Synthesis, Characterisation and Study of Optical Properties
    (Punjab Agricultural University, Ludhiana, 2018) Baweja, Himani; Kiran Jeet
    Carbon based quantum dots are the emerging class of nanomaterials that consists of graphene quantum dots (GQDs) and carbon quantum dots (CQDs), have gained tremendous attention for their characteristics such as good stability, highly fluorescent nature, biocompatibility and chemical inertness. In this study, we aimed to develop a simple, efficient, economic and sustainable approach for synthesis of carbon based quantum dots from agricultural waste. Sugarcane bagasse is one of the major solid agricultural waste. We developed a novel strategy for efficient recycling of agricultural waste to synthesize carbon based quantum dots from sugarcane bagasse. Herein, graphene quantum dots have been synthesized by chemical cutting from graphene oxide. Chemical oxidation followed by exfoliation method was used to synthesise carbon quantum dots. The as synthesised carbon based quantum dots were structurally characterised by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The quantum dots were optically characterised by Fluorescence microscopy and UV-vis spectroscopy. Carbon based quantum dots were highly fluorescent in nature. The particles were seen with blue emission under UV filter. SEM and TEM analysis indicate size, shape and monodispersed nature of carbon based quantum dots along with structural information about graphene oxide and sugarcane bagasse. The presence of large amount of oxygenous functionality was confirmed by FT-IR spectra and UV-vis spectroscopy. The synthesis process focuses on agricultural waste management by using sugarcane bagasse as precursor for developing carbon based quantum dots which possesses noble optical properties and thus wide range of applications.