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20214
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Subject: Mechanical Engineering × End date: 2021 × Start date: 2021 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Fabrication and evaluation of nanobentonite/epoxy laminated poplar veneer lumbers
    (G. B. Pant University of Agriculture and Technology, Pantnagar, 2021-07) Mohd Arif; Misra, Anadi
    A method of modification of poplar wood veneers (PWVs) was developed through adhesive bonding with bentonite epoxy nanocomposites (BENs).The process of adhesive bonding was executed through alternate laying of BENs across 4- layers of PWVs by pressing at 10kg/cm2 over 24h.This has afforded laminated veneer lumbers (LVLs) with improve mechanical properties, thermal and dimensional stability. LVLs were characterized through Fourier transformed infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. Effect of weight fraction (WF, wt%) of nanobentonite (NB) ranging 0 to 3.0 on mechanical properties, thermal and dimensional stability of LVLs was investigated with reference to PWVs as control. With WF of NB, the LVLs have rendered ultimate modification (%) in their flexural (80.49), tensile (63.81) and impact strength (18.35) at 2.0 WF of NB over PWVs. LVLs at 12 mm thickness with 2 WF of NB has rendered water resistance by 48.97% and thickness swelling (27.46%) over PWVs. Simultaneous thermogravimetric-differential thermal analysis (TG-DTA-DTG) reveals reduction in moisture content of LVLs ranging 4.92 to 1.4 with WF of NB. TG-DTA reveals onset temperature of degradation of LVLs at 200o C with marginal reduction in their heat of fusion over PVWs. DTG reveals thermal degradation (mg/min) of LVLs ranging 0.79 to 0.41 in the temperature range of 287.93 to 294.40oC. TG endset of LVLs was commenced in the temperature range of 485.78 to 600.68o C with heat of fusion (J/mg) ranging 49.5 to 50.8 and average char residue of 3.45% .The present study reveals sustainable modification of PWVs thorough adhesive boding with BENs to deliver the LVLs with improved durability, thermal and dimensional stability.
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    ThesisItemOpen Access
    Fabrication and evaluation of nanobentonite/epoxy laminated poplar veneer lumbers
    (G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2021-07) Mohd Arif; Misra, Anadi
    A method of modification of poplar wood veneers (PWVs) was developed through adhesive bonding with bentonite epoxy nanocomposites (BENs).The process of adhesive bonding was executed through alternate laying of BENs across 4- layers of PWVs by pressing at 10kg/cm2 over 24h.This has afforded laminated veneer lumbers (LVLs) with improve mechanical properties, thermal and dimensional stability. LVLs were characterized through Fourier transformed infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. Effect of weight fraction (WF, wt%) of nanobentonite (NB) ranging 0 to 3.0 on mechanical properties, thermal and dimensional stability of LVLs was investigated with reference to PWVs as control. With WF of NB, the LVLs have rendered ultimate modification (%) in their flexural (80.49), tensile (63.81) and impact strength (18.35) at 2.0 WF of NB over PWVs. LVLs at 12 mm thickness with 2 WF of NB has rendered water resistance by 48.97% and thickness swelling (27.46%) over PWVs. Simultaneous thermogravimetric-differential thermal analysis (TG-DTA-DTG) reveals reduction in moisture content of LVLs ranging 4.92 to 1.4 with WF of NB. TG-DTA reveals onset temperature of degradation of LVLs at 200o C with marginal reduction in their heat of fusion over PVWs. DTG reveals thermal degradation (mg/min) of LVLs ranging 0.79 to 0.41 in the temperature range of 287.93 to 294.40oC. TG endset of LVLs was commenced in the temperature range of 485.78 to 600.68o C with heat of fusion (J/mg) ranging 49.5 to 50.8 and average char residue of 3.45% .The present study reveals sustainable modification of PWVs thorough adhesive boding with BENs to deliver the LVLs with improved durability, thermal and dimensional stability.
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    ThesisItemOpen Access
    Effect of n-Pentanol addition to methanol-diesel blends on combustion stability, knock, performance and emission characteristics of diesel engine
    (G. B. Pant University of Agriculture and Technology, Pantnagar, 2021-12) Vishnoi, Pradeep Kumar; Gupta, V.K.
    The present study investigates the influence of n-pentanol addition to diesel/methanol blends on diesel engine performance, combustion, knock, and emission characteristics at different loading conditions. The experiments were performed for diesel and five different test fuels namely MnP5 (5% methanol+5% n-pentanol+90% diesel), MnP10 (10% methanol+10% n-pentanol+80% diesel), MnP15 (15% methanol+15% npentanol+80% diesel), MnP20 (20% methanol+20% n-pentanol+60% diesel) and MnP25 (25% methanol+25% n-pentanol+50% diesel). Performance characteristics were evaluated by using a fuel consumption test. Moreover, combustion and knock characteristics were evaluated based on in-cylinder pressure measurement and heat release analysis. Further, combustion stability analysis was conducted by using statistical and wavelet methods. The peak pressure data series was used for statistical and wavelet analysis. The results indicate that n-pentanol can stabilize the diesel-methanol blend and improve the properties of npentanol-methanol-diesel blends. The brake thermal efficiency for all test fuels and exhaust gas temperature for all test fuels was higher than that of the diesel. Longer ignition delay was observed for all the blends except MnP5 at lower load conditions, while shorter ignition delay was observed at high load conditions. Further, the ignition delay was increased with the increase in methanol and n-pentanol percentage in the test fuel blends. The peak pressure and rate of heat release for all the blends except Mn25 were higher than that of diesel at high load conditions. Knock, and ringing intensities for MnP5 were found to be higher than diesel at all loads. NOx emission for all the blends was lower than diesel at all loading conditions, while HC and smoke emission for MnP5 and MnP10 was lower than diesel at high load conditions. CO emission was found to be higher than diesel for all the blends at all loading conditions. Furthermore, coefficient of variation (COV), wavelet power spectrum (WPS), and global wavelet spectrum (GWS) power indicate that MnP25 exhibits very high cyclic variation.
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    ThesisItemOpen Access
    Mechanical and thermal characterization of biodegradable cellulose nanofiber reinforced polyvinyl alcohol/chitosan blend
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-03) Somvanshi, Kritika Singh; Gope, P.C.
    In recent years, due to increased awareness and push towards more environmentally sustainable technology, nano-composite materials obtained from natural and renewable resources have received significant interest. Cellulose Nano Fiber (CNF) is the most profuse, recyclable and eco-friendly natural fiber which entirely disintegrated by the appropriate action of microorganisms. Polyvinyl Alcohol and Chitosan blend films were prepared by solution casting method and ultrasonic processing at 20, 30, 40 and 50 wt. % of CNF. The dispersion of Nano filler in a solution obtained by energetic agitation by the sonication process resulted in improved mechanical and thermal properties. The performance of the films was comprehensively investigated in terms of water absorption, mechanical properties, thermal stability, biodegradability, antimicrobial and antioxidant properties. DMA analysis of the film has been studied to determine the storage modulus, loss modulus and glass transition temperature. The homogeneous dispersion is studied using scanning electron micrographs. Optimization of different process parameters is studied using Analysis of Variance and Response Surface Methodology. The optimized film exhibited a strong antibacterial effect against Staphylococcus aureus bacterial strain with a 15.96 mm zone of inhibition diameter. Creep and recovery behavior were also examined and found that the rigidity and load-bearing capability are improved by CNF reinforcement. A soil burial test was conducted to investigate the biodegradability that shows improved degradation within a very short time. The improved results for mechanical, thermal, creep, antibacterial, antioxidant and biodegradability are recorded in the film with 30 min sonicated and 40 wt. % CNF reinforcement. The soil analysis results reveal that the optimized film can be used in various applications in the field of agriculture and food packaging.