Roles of resonant muonic molecule in new kinetics model and muon catalyzed fusion in compressed gas.

Muon catalyzed fusion ([Formula: see text]CF) in which an elementary particle, muon, facilitates the nuclear fusion between the hydrogen isotopes has been investigated in a long history. In contrast to the rich theoretical and experimental information on the [Formula: see text]CF in cold targets, there is relatively scarce information on the high temperature gas targets of deuterium-tritium mixture with high-thermal efficiency. We demonstrate new kinetics model of [Formula: see text]CF including three roles of resonant muonic molecules, (i) changing isotopic population, (ii) producing epi-thermal muonic atoms, and (iii) inducing fusion in-flight. The new kinetics model reproduces experimental observations, showing higher cycle rate as the temperature increasing, over a wide range of target temperatures ([Formula: see text] K) and tritium concentrations. Moreover, it can be tested by measurements of radiative dissociation X-rays around 2 keV. High energy-resolution X-ray detectors and intense muon beam which are recently available are suitable to reveal these dynamical mechanism of [Formula: see text]CF cycles. Towards the future [Formula: see text]CF experiments in the high-temperature gas target we have clarified the relationship between the fusion yield and density-temperature curve of adiabatic/shock-wave compression.

In situ analysis of reaction kinetics of reduction promotion of NiMn2O4 under microwave H-field irradiation.

Reaction kinetics during microwave H-field heating and electric furnace heating were investigated to verify the effect of rapid heating and the non-thermal microwave effect. This work is focused on the ferromagnetic material NiMn2O4, and the reduction reaction under rapid heating is investigated using an in situ analysis device. The results showed that the activation energy varied with the heating rate under microwave H-field irradiation, and it was the same as that in an electric furnace when the heating rate was the same. On the other hand, under microwave H-field irradiation, the reduction reaction began from a significantly low temperature compared with that of electric furnace heating. The results suggest that the transition theory during microwave irradiation should be expanded to include the effect of spin waves excited by a microwave H-field on magnetic materials.

The microwave heating mechanism of N-(4-methoxybenzyliden)-4-butylaniline in liquid crystalline and isotropic phases as determined using in situ microwave irradiation NMR spectroscopy.

Microwave heating effects are widely used in the acceleration of organic, polymerization and enzymatic reactions. These effects are primarily caused by the local heating induced by microwave irradiation. However, the detailed molecular mechanisms associated with microwave heating effects on the chemical reactions are not yet well understood. This study investigated the microwave heating effect of N-(4-methoxybenzylidene)-4-butylaniline (MBBA) in liquid crystalline and isotropic phases using in situ microwave irradiation nuclear magnetic resonance (NMR) spectroscopy, by obtaining (1)H NMR spectra of MBBA under microwave irradiation. When heated simply using the temperature control unit of the NMR instrument, the liquid crystalline MBBA was converted to the isotropic phase exactly at its phase transition temperature (Tc) of 41 °C. The application of microwave irradiation at 130 W for 90 s while maintaining the instrument temperature at 20 °C generated a small amount of isotropic phase within the bulk liquid crystal. The sample temperature of the liquid crystalline state obtained during microwave irradiation was estimated to be 35 °C by assessing the linewidths of the (1)H NMR spectrum. This partial transition to the isotropic phase can be attributed to a non-equilibrium local heating state induced by the microwave irradiation. The application of microwave at 195 W for 5 min to isotropic MBBA while maintaining an instrument temperature of 50 °C raised the sample temperature to 160 °C. In this study, the MBBA temperature during microwave irradiation was estimated by measuring the temperature dependent chemical shifts of individual protons in the sample, and the different protons were found to indicate significantly different temperatures in the molecule. These results suggest that microwave heating polarizes bonds in polar functional groups, and this effect may partly explain the attendant acceleration of organic reactions.

Mechanism for microwave heating of 1-(4'-cyanophenyl)-4-propylcyclohexane characterized by in situ microwave irradiation NMR spectroscopy.

Microwave heating is widely used to accelerate organic reactions and enhance the activity of enzymes. However, the detailed molecular mechanism for the effect of microwave on chemical reactions is not yet fully understood. To investigate the effects of microwave heating on organic compounds, we have developed an in situ microwave irradiation NMR spectroscopy. (1)H NMR spectra of 1-(4'-cyanophenyl)-4-propylcyclohexane (PCH3) in the liquid crystalline and isotropic phases were observed under microwave irradiation. When the temperature was regulated at slightly higher than the phase transition temperature (Tc=45 °C) under a gas flow temperature control system, liquid crystalline phase mostly changed to the isotropic phase. Under microwave irradiation and with the gas flow temperature maintained at 20 °C, which is 25 °C below the Tc, the isotropic phase appeared stationary as an approximately 2% fraction in the liquid crystalline phase. The temperature of the liquid crystalline state was estimated to be 38 °C according to the line width, which is at least 7 °C lower than the Tc. The temperature of this isotropic phase should be higher than 45 °C, which is considered to be a non-equilibrium local heating state induced by microwave irradiation. Microwaves at a power of 195 W were irradiated to the isotropic phase of PCH3 at 50 °C and after 2 min, the temperature reached 220 °C. The temperature of PCH3 under microwave irradiation was estimated by measurement of the chemical shift changes of individual protons in the molecule. These results demonstrate that microwave heating generates very high temperature within a short time using an in situ microwave irradiation NMR spectrometer.

Microwave-driven asbestos treatment and its scale-up for use after natural disasters.

Asbestos-containing debris generated by the tsunami after the Great East Japan Earthquake of March 11, 2011, was processed by microwave heating. The analysis of the treated samples employing thermo gravimetry, differential thermal analysis, X-ray diffractometry, scanning electron microscopy, and phase-contrast microscopy revealed the rapid detoxification of the waste by conversion of the asbestos fibers to a nonfibrous glassy material. The detoxification by the microwave method occurred at a significantly lower processing temperature than the thermal methods actually established for the treatment of asbestos-containing waste. The lower treatment temperature is considered to be a consequence of the microwave penetration depth into the waste material and the increased intensity of the microwave electric field in the gaps between the asbestos fibers resulting in a rapid heating of the fibers inside the debris. A continuous treatment plant having a capacity of 2000 kg day(-1) of asbestos-containing waste was built in the area affected by the earthquake disaster. This treatment plant consists of a rotary kiln to burn the combustible waste (wood) and a microwave rotary kiln to treat asbestos-containing inorganic materials. The hot flue gas produced by the combustion of wood is introduced into the connected microwave rotary kiln to increase the energy efficiency of the combined process. Successful operation of this combined device with regard to asbestos decomposition is demonstrated.

Continuous pig iron making by microwave heating with 12.5 kW at 2.45 GHz.

A continuous process of pig iron making using microwave of 2.45 GHz was constructed in a microwave furnace with maximum power of 12.5 kW. Pig iron was produced from the mixed powder of magnetite ore and carbon such as coal, coke and graphite. Molten pig iron initially poured from reaction chamber after about 40 min when temperature attained over 1200 degrees C. After temperature attained at 1400 degrees C, 50 or 200 g of mixed powder was added several times in regular interval and pig iron continuously dropped out from reaction chamber. When mixed powder was supplied, temperature in reaction chamber decreased by about 200 degrees C and recovered during 5 min. Finally, the recovery time of temperature lengthened. In order to make the scale-up of the microwave furnace for iron making, it has been discussed how to improve energy efficiency and to make a preferable construction.

Fabrication of Ni-Nb-Sn metallic glassy alloy powder and its microwave-induced sintering behavior.

In the present study, we prepared Ni59.35Nb34.45Sn6.2 metallic glassy alloy powder by an argon gas atomization process. Microwave (MW)-induced heating and sintering was carried out by a single-mode 2.45 GHz MW applicator in the separated magnetic field or electric field using the obtained glassy powders. The structure and thermal stability of the sintered glassy alloy specimens were investigated.

Enhanced heating of salty ice and water under microwaves: molecular dynamics study.

Through the use of molecular dynamics simulations, we have studied the enhanced heating of salty ice and water by the electric field of applied microwaves at 2.5 GHz, and in the range of 2.5-10 GHz for the frequency dependence. We show that water molecules in salty ice are allowed to rotate in response to the microwave electric field to the extent comparable to those in pure water because the molecules in salty ice are loosely tied by hydrogen bonds with adjacent molecules unlike rigidly bonded pure ice. The weakening of hydrogen-bonded network of molecules in salty ice is mainly due to the electrostatic effect of salt ions rather than the short-range geometrical (size) effect of salt since the presence of salt ions with small radii causes similar enhanced heating.

Evolution of the near-UV emission spectrum associated with the reduction process in microwave iron making.

The structure of the emission spectrum in the near-UV range (240 nm-310 nm) changes drastically from the continuous spectrum to a discrete line spectrum with increasing sample temperature during the carbothermic reduction of magnetite in a 2.45 GHz microwave multimode furnace. The continuous spectrum can be assigned as a cathodoluminescence of magnetite. The dynamic evolution of the spectrum from continuous to discrete represents the progress of the reduction from magnetite to iron.

Microwave heating of water, ice, and saline solution: molecular dynamics study.

In order to study the heating process of water by the microwaves of 2.5-20 GHz frequencies, the authors have performed molecular dynamics simulations by adopting a nonpolarizable water model that has fixed point charges on a rigid-body geometry. All runs are started from the equilibrated states derived from the I(c) ice with given density and temperature. In the presence of microwaves, the molecules of liquid water exhibit rotational motion whose average phase is delayed from the microwave electric field. Microwave energy is transferred to the kinetic and intermolecular energies of water, where one-third of the absorbed microwave energy is stored as the latter energy. The water in ice phase is scarcely heated by microwaves because of the tight hydrogen-bonded network of water molecules. Dilute salt water is significantly more heated than pure water because of the field-induced motion of salt ions, especially that of large-size ions, by the microwave electric field and energy transfer to water molecules by collisions.

Analysis of pyrolysis products of methamphetamine.

This study examined the pyrolysis products of d-methamphetamine (d-MA) and the pyrolysis mechanism. A sealed glass tube, in which MA-HCl was placed, was wrapped with pyrolysis-foil and heated at the Curie point of the pyrolysis-foil. The pyrolysis products of MA were detected by gas chromatography-mass spectrometry and liquid chromatography-electrospray ionization-mass spectrometry. MA-d(3)-HCl, in which all the hydrogen atoms of N-methyl group of MA were substituted with deuterium atoms, was pyrolyzed to investigate the transformation of a methyl group of MA. Amphetamine (AM) and dimethylamphetamine (DMA) were produced via demethylation and methylation reactions, respectively, at temperatures above 315 degrees C. The demethylation and methylation reactions were the major pyrolysis processes at temperatures below 358 degrees C. At temperatures above 315 degrees C, the reaction of DMA with a methyl group eliminated from the methylamino group of MA resulted in the formation of benzylethyltrimethylammonium (BEMA). This transformation reveals that demethylation and methylation reactions occur in the form of a methyl cation. The thermal degradation of BEMA, the abstraction of a proton at the beta-position and the elimination of a trimethylamine, produced allylbenzene, cis-beta-methylstyrene, and trans-beta-methylstyrene at temperatures above 315 degrees C. At temperatures above 445 degrees C, the optical isomers, or l-isomers of AM, MA, and DMA, were produced as pyrolysis products.

Analysis of dimethylamphetamine and its metabolites in human urine by liquid chromatography-electrospray ionization-mass spectrometry with direct sample injection.

An analytical method to identify and determine dimethylamphetamine (DMA) and its metabolites in human urine was developed with liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) involving the direct injection of a urine sample. The urine samples were directly injected by using a gel permeation column, whose stationary phase was polyvinyl alcohol with a small amount of a carboxyl group, so DMA and its metabolites were analyzed rapidly and simply without pretreatment such as extraction, concentration and derivatization. DMA and its metabolites were identified in drug-free human urine spiked with 1 microg of DMA, dimethylamphetamine N-oxide (DMANO) and methamphetamine (MA), and 3 microg of amphetamine (AM) in 1 ml of urine under the full-scan mode. Under the selected ion monitoring (SIM) mode, the limits of detection (signal-to-noise ratio=5) for DMA, DMANO, MA and AM were 20, 20, 20 and 60 ng in 1 ml of urine, respectively. This method was applied to the identification and determination of DMA and its metabolites in urine samples of 10 DMA abusers. The concentrations of DMANO were higher than those of unchanged DMA in all urine samples; thus, DMANO is considered to be a useful metabolite as an indicator to prove DMA intake.