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ThesisItem Open Access Influence of ohmic heating on electrical properties of tomato puree(Punjab Agricultural University, Ludhiana, 2019) Kiranjot Kaur; Paramjit SinghOhmic 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.ThesisItem Restricted Improved randomised response technique for estimation of sensitive character(Punjab Agricultural University, Ludhiana, 2019) Manpreet Kaur; Grewal, Inderjit SinghGetting 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).ThesisItem Restricted Interrelationship between electrical conductivity, refractive index and viscosity of honey(Punjab Agricultural University, Ludhiana, 2019) Jasleen Kaur; Paramjit SinghThe 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).ThesisItem Open 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 KumarA 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.ThesisItem Restricted Determination of moisture content, mass attenuation coefficient and density of Oak and Mango wood using gamma radiations.(Punjab Agricultural University, Ludhiana, 2019) Arshdeep Kaur; Rajeev KumarDue to the availability and particular features, wood is one of the first materials used by mankind with a wide variety of applications. Changes in moisture content lead to changes of virtually all physical and mechanical properties (e.g. shrinkage or swelling, strength and stiffness properties) of wood. The present study deals with the determination of mass attenuation coefficient of Oak(Grevillea robusta) and Mango(Mangifera indica) wood samples as it varies across material thickness and at varying moisture levels using gamma ray transmission method. NaI(Tl) scintillation detector and a radioactive source 137Cs of energy 0.662 MeV was used. Wood samples were placed in an oven for fixed durations to vary moisture levels. Logarithmic relative transmitted intensities were plotted against the thickness of wood samples and mass attenuation coefficients were obtained from the slopes of plots at different moisture levels. The obtained mass attenuation coefficients were plotted against the relative moisture content of wood samples and it is obtained that attenuation varies with decreasing moisture content i.e., the mass attenuation coefficient was minimum for completely wet state and maximum for oven dry state of the samples. Wood density is also a vital parameter giving knowledge about anatomical and physical properties of wood. Wood densities were also measured for these wood samples by using conventional, oven dry and nuclear method. Owing to the fact that the shielding capacity of wood samples can be determined easily, wood can be used as shielding material from radiation.ThesisItem Open Access Gardner solitons in Electron-Positron-Ion plasma featuring Cairns-Tsallis electrons(Punjab Agricultural University, Ludhiana, 2019) Manpreet Kaur; Parveen BalaSolitary 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.ThesisItem Restricted Estimation of Electrical Conductivity of Aonla (Amla) Juice with Varied TSS Levels Using Ohmic Heating.(Punjab Agricultural University, Ludhiana, 2018) Sarabjeet Kaur; Paramjit SinghNew technologies for thermal processing of liquid foods are of great industrial and scientific interest. Ohmic heating is one of these new technologies. Ohmic heating is also known as resistive heating or Joule heating. In this process, when electrical current is passed through a food substance, the food acts a resistor and heat is generated internally. The present study aimed to design, build and test ohmic heating system. Ohmic heating behavior was studied in amla juice for five different voltage gradients (16, 14, 12, 10 and 8 V/cm) and concentrations (100, 90, 80, 70, 60 %) in the temperature range 30 to 70˚C. Ohmic heating process is influenced by a number of factors such as electrical conductivity, concentration, viscosity, pH, solid content and electric field strength. Results indicated that there was a significant effect of voltage gradients and concentrations on the heating rate and heating rate showed a linear behavior. Also, plots between temperature and electrical conductivity depicted a linear trend. Other parameters- viscosity, pH and total soluble solids (TSS) were measured before and after ohmic heating. Statistical analysis was done on all of these parameters and it was concluded that ohmic heating had no effect on pH and TSS of sample. There was a non- significant effect of this treatment on viscosity at 12 V/cm and significant effect on rest of the voltage gradients. System performance coefficient (SPC) was calculated for all voltage gradients and all concentrations. It was observed that SPC was higher for 16V/cm for all concentrations and its value decreased as the voltage gradient was decreased.ThesisItem Restricted Carbon Based Quantum Dots: Synthesis, Characterisation and Study of Optical Properties(Punjab Agricultural University, Ludhiana, 2018) Baweja, Himani; Kiran JeetCarbon 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.