Plasma-assisted priming : improved germination and seedling performance of papaya

Papaya is a one of the important tropical fruit crops with a global export of 353 ktonnne reported in 2020. The germination of papaya seed is erratic and often non-uniform. Plasma assisted priming of seed was performed at atmospheric pressure in a parallel plate dielectric barrier discharge system. The germination rate of papaya seeds and the growth performance of the seedling were monitored for several treatment plans combining the atmospheric pressure plasma treatment with soaking of seed in deionized water. An enhanced germination rate of 92% was obtained by the plasma assisted priming, compared to the untreated of 60%. The plasma assisted priming performed by plasma treatment and soaking in an opposite sequence showed different requirement and possibly involved different mechanisms. The treatment time was reduced to only 4 minutes for pre-soaked seeds, otherwise the germination rate increased with the plasma treatment time from 3 to 30 min treatment. The plasma assisted priming approaches were also found enhancing seedling growth performance. The treated seedling grows about two times bigger and the dried mass measured after 30 days was more than 100% compared to that of the untreated and hot water treated seeds

Effect of multi-walled carbon nanotubes reinforcement and gamma irradiation on viscoelastic properties of ultra-high molecular weight polyethylene

Ultra-high molecular weight polyethylene (UHMWPE) has been used as a surface for acetabular in total joint replacements for the past 60 years. However, the performance of the implant is influenced by the increase in temperature because of the articulating motion and the contact asperities, which affects its longevity. The viscoelastic properties of multi-walled carbon nanotubes (MWCNTs) reinforced UHMWPE nanocomposites with respect to temperature and irradiation dose are not reported so far. Hence, an attempt was made to study the viscoelastic properties of UHMWPE by varying concentration of MWCNTs and intensity of irradiation dose. The test samples were subjected to sinusoidal loading in the temperature range of 30–80°C. Ultra-high molecular weight polyethylene nanocomposites were prepared at different concentrations of MWCNTs such as 0.5, 1.0, 1.5 and 2 wt-% using compression moulding process and the nanocomposites were subjected to ⁶⁰Co gamma irradiation up to 100 kGy dose. The viscoelastic characteristics of UHMWPE, such as storage modulus, loss moduls and damping factor of the irradiated nanocomposites, were studied in detail. It was observed that the storage modulus of the pure UHMWPE was increased by 139% with the addition of 2 wt-% MWCNTs; however, it was found to be reduced by 83% with 100 kGy irradiation doses. The damping factor and loss modulus of the nanocomposites were reduced by 27.3 and 71.6% with 2 wt-% of MWCNTs concentration, but both were increased with 100 kGy irradiation dose by 74.7 and 69% compared to virgin UHMWPE. It is concluded that the storage modulus reduced with the increase in temperature and also irradiation dose, which may lead to higher static deformation of material. However, the presence of MWCNTs would minimise the deformation and pave way for the better functionality of the material

Association Proposal Presentation.pptx

Biomedical Engineering Association Presentation

Effect of γ-Irradiation on Thermal Properties of MWCNTs Reinforced HDPE

Crosslinking by gamma irradiation is a key technique employed in industrial and medical application of polymers to improve their mechanical and thermal properties. The objective of the present work is to investigate the effect of gamma irradiation on thermal properties of high density polyethylene (HDPE) reinforced with multiwalled carbon nanotubes (MWCNTs). The chemically treated MWCNTs were coated on HDPE pellets using nanofluid based deposition technique under continuous stirring, which were processed in an injection moulding machine to obtain nanocomposites having 0.25, 0.50, 0.75 and 1.0 wt% of MWCNTs. The nanocomposites thus obtained were exposed to γ-irradiation in the presence of air at 50 and 100 kGy doses. Thermal characterization of nanocomposites was studied using DSC, TGA and TMA techniques. The results obtained from the DSC studies revealed that the melting point of nanocomposites was not significantly influenced by the presence of MWCNTs, while γ-irradiation resulted a marginal change. The crystallinity of the nanocomposites was increased from 37.4 % for unirradiated HDPE to 55.8 % for 1.0 wt% and 100 kGy irradiated sample, which corresponds to 49 % enhancement. The onset temperature of degradation of nanocomposites was found to be influenced by both MWCNTs and irradiation dosage, which was increased by 16 °C for 100 kGy irradiated 1 wt% nanocomposite compared to unirradiated pure polymer. It is also found that the dimensional stability of the nanocomposites was increased by the reinforcement of MWCNTs. It is concluded from the above studies that thermal properties of nanocomposites are significantly influenced by the irradiation process and the concentration of MWCNTs.<div><br></div

Comparison of Elastic Modulus of MWCNT Polyethylene Composites using Nanoindentaion and Macromechanical Analysis.pdf

Ultra high molecular weight polyethylene (UHMWPE) has been in use as an articulating surface in total joint replacements. However, there are critical problems like reduced longevity owing to high activity on the hip joint. In the present study, UHMWPE is reinforced with MWCNTs at different concentration by physical blending using ball milling technique. The samples were obtained using a compression moulding machine, which were used for study under nanoindenter to obtain the elastic modulus. The MWCNTs were randomly oriented and the obtained values of elastic modulus of the composites were compared with that of analytical models like Halpin-Tsai model. The elastic properties of the composites were then analytically estimated for different orientations of carbon nanotubes such as 0o, 15o, 30o, 45o, 60o, 75o, and 90o at different volume fractions upto 0.5 %. Different properties like elastic modulus in x and y direction, Poisson’s ratio, in-plane shear modulus and shear coupling coefficients were also calculated and plotted

Does Society Need Biomedical Engineers ??

Study on biomedical Engineering education <div><br></div><div>Medical Device Industry in India </div><div><br></div><div>Need recognition and promotion of Biomedical Engineering in India. </div

Low-Energy Plasma Focus Device as an Electron Beam Source

A low-energy plasma focus device was used as an electron beam source. A technique was developed to simultaneously measure the electron beam intensity and energy. The system was operated in Argon filling at an optimum pressure of 1.7 mbar. A Faraday cup was used together with an array of filtered PIN diodes. The beam-target X-rays were registered through X-ray spectrometry. Copper and lead line radiations were registered upon usage as targets. The maximum electron beam charge and density were estimated to be 0.31 μC and /m3, respectively. The average energy of the electron beam was 500 keV. The high flux of the electron beam can be potentially applicable in material sciences

polymers-08-00295.pdf

AbstractUltra-high molecular weight polyethylene (UHMWPE) is widely used in artificial joints in the replacement of knee, hip and shoulder that has been impaired as a result of arthritis or other degenerative joint diseases. The UHMWPE made plastic cup is placed in the joint socket in contact with a metal or ceramic ball affixed to a metal stem. Effective reinforcement of multi-walled carbon nanotubes (MWCNTs) in UHMWPE results in improved mechanical and tribological properties. The hydrophobic nature of the nanocomposites surface results in lesser contact with biological fluids during the physiological interaction. In this project, we investigate the UHMWPE/MWCNTs nanocomposites reinforced with MWCNTs at different concentrations. The samples were treated with cold argon plasma at different exposure times. The water contact angles for 60 min plasma-treated nanocomposites with 0.0, 0.5, 1.0, 1.5, and 2.0 wt % MWCNTs were found to be 55.65°, 52.51°, 48.01°, 43.72°, and 37.18° respectively. Increasing the treatment time of nanocomposites has shown transformation from a hydrophobic to a hydrophilic nature due to carboxyl groups being bonded on the surface for treated nanocomposites. Wear analysis was performed under dry, and also under biological lubrication, conditions of all treated samples. The wear factor of untreated pure UHMWPE sample was reduced by 68% and 80%, under dry and lubricated conditions, respectively, as compared to 2 wt % 60 min-treated sample. The kinetic friction co-efficient was also noted under both conditions. The hardness of nanocomposites increased with both MWCNTs loading and plasma treatment time. Similarly, the surface roughness of the nanocomposites was reduced

Effect of MWCNT on mechanical properties of γ-irradiated UHMWPE during shelf ageing process

Crosslinking of UHMWPE by gamma irradiation has been the prime choice to improve the wear resistance of the polymer. However, it is always associated with few setbacks like degradation of material properties during the shelf ageing period. In the present work, nanocomposites were prepared using ball milling process and then compression moulding process where UHMWPE was reinforced by MWCNTs with 0.20 and 0.40 wt. %. The samples were gamma irradiated using 60Co at 25 and 50 kGy sterilizing doses in air without any post irradiative treatments and then shelf aged for 240 days. The mechanical properties of the composites were studied using small punch technique according to ASTM F2183 standards. Both toughness and hardness of the composites were found to be improved with an increase of irradiation dosage and MWCNT concentration. It is observed that the percentage reduction in Young’s modulus, yield stress and % strain at fracture of 0.4% composite at 50 kGy dose are 6.4%, 8.8% and 12.7%, respectively compared to that of virgin UHMWPE irradiated at same dosage. It is concluded that presence of MWCNTs in UHMWPE prevents the degradation of material properties during the shelf ageing period after irradiation

V6 News (Hyderabad, Telangana State, India) coverage on Biomedical Engineers in Government Hospitals

Importance of Biomedical Engineers in Government Hospitals clearly explained my Honorary President Rangarajan of Biomedical Engineering Association of Telangana State (BEATS) News coverage by  V6 News on 28 September 201