https://aasldpubs.onlinelibrary.wiley.com/doi/pdf/10.1002/hep.21280

Liver biopsy interpretation for causes of late liver allograft dysfunction

A review on the susceptor assisted microwave processing of materials

Progressive histological damage in liver allografts following pediatric liver transplantation

Recent advances in soft optical glass fiber and fiber lasers

Enhanced mass transport during the high temperature processing of ceramics by microwave heating, generally known as the 'microwave effect', has been observed by many researchers and some hypotheses have been proposed to explain it. However it is still a controversial issue, centring on temperature measurement accuracy. The primary goal for the present work was to achieve definitive evidence of the microwave effect via the microwave hybrid processing of ceramics using accurate temperature measurement.


Three temperature measurement techniques, viz. thermocouple, pyrometer and optical fibre thermometer, have been investigated to determine their accuracy during the hybrid microwave heating of ceramic materials. The experimental results, obtained from melting point measurement on vanadium pentoxide and the heating of three other materials with different loss factors and thermal conductivities, showed that the optical fibre thermometer was the best choice. An accuracy of ±2oC was obtained,
provided the probe had been calibrated and was protected from stray radiation from conventional heating elements.


Direct evidence for the microwave effect was sought from experiments involving the sintering and annealing of ceramics at different microwave power levels but using an identical temperature I time profile in each case. Sample temperature was monitored using optical fibre thermometry and sample size, composition and precursor powder size were all varied. Specifically, four main ceramics with different loss factors were investigated, viz. zinc oxide (very lossy), yttria stabilised zirconia (intermediate loss) and alumina and silica (low loss).


The results from the experiments showed that an increase in final density was observed for the samples that saw the highest microwave power level compared to


I
 
those sintered using pure conventional heating, nearly 25% in the largest case for zinc oxide with the highest loss factor among the four investigated materials. This was equivalent to an effective temperature increase of approximately 1OOoC. For the low
loss alumina samples, the increase was extremely small, with the yttria stabilised zirconia intermediate between the two. In addition, during annealing of fully dense ZnO ceramic pellets, enhanced grain growth was observed during hybrid heating compared to pure conventional heating. Temperature gradients within the samples, a major potential cause of the effect, were assessed using two different approaches and found to be

Evidence for the microwave effect during hybrid sintering and annealing of ceramics

Industrial waste derived biosorbent for toxic metal remediation: Mechanism studies and spent biosorbent management

This paper reports the dopant ion (Nd3+) concentration effects on its luminescence properties in a new glass system based on barium-alumino-metaphosphates. Amongst the studied concentrations range of 0.276–13.31×1020 ions/cm3, the glass with 2.879×1020 ions/cm3 (1 mol%) Nd3+ concentration shows intense NIR emission from 4F3/2 excited state, followed by a decrease in emission intensity for further increase in Nd3+ ion concentration. The observed luminescence quenching is ascribed to Nd3+ self-quenching through the donor-donor migration assisted cross-relaxation mechanism. The microscopic energy transfer parameters for donor-acceptor energy transfer, C
 DA, and donor-donor energy migration, C
 DD, have been obtained from the theoretical fittings to experimental decay curves and the spectral overlap model respectively. The C
 DD parameters (×10−39 cm6/sec) are found to be about three orders greater than that of C
 DA (×10−42 cm6/sec) for Nd3+ self-quenching in this host, demonstrating that the excitation energy migration among donors is due to the hopping mechanism. The energy transfer micoparameters obtained in the present study are comparable to the values reported for commercially available laser glasses LHG-8 and Q-98.

/pdf/concentration-quenched-luminescence-and-energy-transfer-5g6sgn3rz8.pdf

Concentration quenched luminescence and energy transfer analysis of Nd 3+ ion doped Ba-Al-metaphosphate laser glasses

Material processing adopting microwave heating has emerged as an alternative tool owing to faster processing, a cleaner environment, and several other advantages. This review provides a summary of recent reports of microwave synthesis of materials. This study reviews the use of microwave energy for application in several material processing technologies apart from food processing. A special emphasis has been made in the processing of glass adopting microwave energy. Melting of glass comprising SiO2, P2O5, B2O3 as the main building block has been discussed. It has been revealed that silica, a microwave transparent material as reported earlier, can be heated under microwave heating directly. Microwave absorption of raw materials and different glass system has been discussed. Dielectric properties, particularly loss tangent or loss factor, are presented for some glass composition. Less evaporation of ingredient and low contamination from the crucible wall are noticed during glass melting using microw...

Ashis Kumar Mandal

Papers

Industrial waste derived biosorbent for toxic metal remediation: Mechanism studies and spent biosorbent management

Concentration quenched luminescence and energy transfer analysis of Nd 3+ ion doped Ba-Al-metaphosphate laser glasses

An overview on microwave processing of material: A special emphasis on glass melting

Utilization of multi-metal laden spent biosorbent for removal of glyphosate herbicide from aqueous solution and its mechanism elucidation

Energy transfer based NIR to visible upconversion: Enhanced red luminescence from Yb3+/Ho3+ co-doped tellurite glass