Until recently traditional heating in organic chemistry has been done with oil heating baths or using electric heat exchangers. With the advent of microwave equipment, heating by microwaves was rapidly introduced as standard method in organic chemistry laboratories, mainly because of the convenient possibility to operate at high temperature accompanied by accelerated reaction rates. In the pres...

Microwaves are injected into argon and helium helicon plasmas at 6 to 20 mTorr neutral pressure, 1.2 kW pulsed microwave power, up to 500 W continuous RF power, and up to 1 kG magnetic fields, with the objective of heating the tail of the electron energy distribution function (EEDF) and populating ion metastable states. Langmuir probes are used to measure the EEDF and optical emission spectrosc...

In this work we report on an ultrashort pulsed laser annealing-driven devitrification of thin film Cu67Zr33 metallic glass characterized by micro-beam X-ray diffraction and electron microscopy techniques. The essential feature annealing is ultrafast heating (1014 K/s) femtosecond optical excitation followed extremely rapid cooling (1010–12 due to heat dissipation into the substrate. During repe...

Pine sawdust pyrolysis was carried out respectively using microwave and conventional electrical heating at different temperatures in order to understand the properties of pyrolytic products from microwave pyrolysis of biomass. Less char material was obtained by microwave pyrolysis compared to conventional heating at the same temperature. While comparing the components of the pyrolytic gases, it...

Microwave radiation, an electromagnetic radiation, is widely use as a source of heating in organic synthesis. The basic mechanisms observed in microwave assisted synthesis are dipolar polarization and conduction. Microwave assisted organic synthesis (MAOS) has emerged as a new “lead” in organic synthesis. The technique offers simple, clean, fast, efficient, and economic for the synthesis of a l...

The complexity and challenges in noncontact temperature measurements inside microwave-heated catalytic reactors are presented in this paper. A custom-designed microwave cavity has been used to focus the microwave field on the catalyst and enable monitoring of the temperature field in 2D. A methodology to study the temperature distribution in the catalytic bed by using a thermal camera in combin...

A calcium sennoside was extracted by developed microwave assisted extraction technique from Senna leaves. Microwave extraction was carried out at 250 W for 20 minutes, 350 W for 15 minutes and 450 W for 10 min heating period, these produced increase yields of calcium sennosides when compared to conventional heating. The yield of calcium sennosides obtained by microwave extraction was found to b...

A hybrid calorimeter is described whereby the test specimen may be heated using either hot air and/or microwave radiation. Thus it is possible to study phase transitions of materials under conditions ranging from purely conventional heating to pure microwave heating or mixtures thereof. Measurements using silver iodide showed that its phase change from the low temperature β-phase to the high te...

Microwave energy has been in use for variety of applications for over 50 years. These applications include communication, food processing, wood drying, rubber vulcanization, medical therapy, polymers, etc. In the last two decades microwave heating has been also applied very effectively and efficiently to heat and sinter ceramic materials. Microwave heating is recognized for its various advantag...

This second paper in a series of two reports on the performance of a new instrument for studying chemical reaction dynamics and kinetics at low temperatures. Our approach employs chirped-pulse Fourier-transform microwave (CP-FTMW) spectroscopy to probe photolysis and bimolecular reaction products that are thermalized in pulsed uniform flows. Here we detail the development and testing of a new K...