Radon and 'King Solomon's Miners': Faynan Orefield, Jordanian Desert

Concentrations of 222Rn were measured in ancient copper mines which exploited the Faynan Orefield in the South-Western Jordanian Desert. The concentrations of radon gas detected indicate that the ancient metal workers would have been exposed to a significant health risk and indicate that any future attempt to exploit the copper ores must deal with the hazard identified. Seasonal variations in radon concentrations are noted and these are linked to the ventilation of the mines. These modern data are used to explore the differential exposure to radon and the health of ancient mining communities.     

Analysis of Methods for Parallel Operation of Frequency Converters

Consideration is given to methods for the parallel operation of frequency converters by applying the active load division. The simulation model of the converter is presented. It consists of three parallel independent modules. A new principle of constructing individual modules of a frequency converter and the principle of their communication interface exhibiting resistance to destabilizing effects and allowing safe operation under nominal conditions even with a 5- to 10% range in time and amplitude values of pilot signals are developed.     

Fitting interrelated datasets: metabolite diffusion and general lineshapes

Objective

Simultaneous modeling of true 2-D spectroscopy data, or more generally, interrelated spectral datasets has been described previously and is useful for quantitative magnetic resonance spectroscopy applications. In this study, a combined method of reference-lineshape enhanced model fitting and two-dimensional prior-knowledge fitting for the case of diffusion weighted MR spectroscopy is presented.

Materials and methods

Time-dependent field distortions determined from a water reference are applied to the spectral bases used in linear-combination modeling of interrelated spectra. This was implemented together with a simultaneous spectral and diffusion model fitting in the previously described Fitting Tool for Arrays of Interrelated Datasets (FiTAID), where prior knowledge conditions and restraints can be enforced in two dimensions.

Results

The benefit in terms of increased accuracy and precision of parameters is illustrated with examples from Monte Carlo simulations, in vitro and in vivo human brain scans for one- and two-dimensional datasets from 2-D separation, inversion recovery and diffusion-weighted spectroscopy (DWS). For DWS, it was found that acquisitions could be substantially shortened.

Conclusion

It is shown that inclusion of a measured lineshape into modeling of interrelated MR spectra is beneficial and can be combined also with simultaneous spectral and diffusion modeling.

     

Response to “On the Radicality of New York’s Reforming the Energy Vision” by Ross Astoria

Dr. Jeff D. Makholm responds to Professor Ross Astoria’s criticms of Dr. Makholm’s submission: “The REVolution yields to a more familiar path: New York’s Reforming the Energy Visition (REV), Electricity Journal 29 (2016), 48–55 as follows.     

Mathematical simulations of the electromagnetic system of a subminiature magnetoelectric engine

This paper is devoted to simulations of a valve electric engine with excitation from high-energy permanent rare-earth magnets. A feature of the design of the engine under consideration is that a stator is manufactured using the polycapillary glass-fiber technique. The conductors of the distributed stator winding are placed in holes pm the tube wall. The cylindrical bipolar rotor is made of iron–neodymium–boron. The assumption accepted in the work during the solving the Laplace equation has made it possible to obtain analytical solutions for the magnetic flux, emf, current, electromagnetic torque, and electromagnetic power.     

The Effects of Annealing After Equal Channel Angular Extrusion (ECAE) on Mechanical and Magnetic Properties of 49Fe-49Co-2V Alloy

Metallurgical and Materials Transactions A - Equal channel angular extrusion (ECAE) of 49Fe-49Co-2V, also known as Hiperco® 50A or Permendur-2V, greatly improves the strength and ductility of...     

Plastic Deformation Resistance of Steel Grades EP450-Sh and EP823-Sh in Hot and Cold State

Metallurgist - The article presents the results of plastometric studies on hot deformation and studies on the hardening curves in cold deformation of EP450-Sh (12H12M1BFR-Sh) and EP823-Sh...     

Remelting of Iron Shavings with the Synergistic Effect of Minimum Metal Loss

Metallurgist - The well-known technologies of remelting iron shavings lead to significant (30%) losses of metal. An electroslag smelting furnace with graphite electrodes is proposed for remelting...     

Combustion in Ni–Al System with Cu Additive (Powder or Rod). Experiment and Mathematical Model

Russian Journal of Non-Ferrous Metals - Experimental studies have been carried out with theoretical calculations of wave synthesis in the Ni–Al–Cu system using a mathematical model....