Space asymptotic method for the study of neutron propagation

Space asymptotic theory is shown to be a suitable model for the study of pulsed experiments in neutron multiplying systems. After a short revisitation of the basic aspects of space asymptotic theory applied on the Laplace transformed one-group transport equation, the full solution is derived. It is shown how results are exact in representing localized pulse propagation in the first portion of the transient, until the boundary is reached by the neutron signal, since it propagates with a finite velocity. Approximate models are then derived starting from the exact formulation and the B_N method is used to account for anisotropy effects. Numerical results are presented for one-dimensional systems, discussing the physical phenomena and noting the distortions introduced by approximate models, which may then turn out to be inadequate for the simulation of realistic pulsed experiments situations.     

Rapid and comprehensive indicator for evaluation of performance of treatment processes and of river waters.

Naturally occurring UV active compounds, commonly present in almost all source waters, can be rapidly monitored by their ultraviolet absorbance at 260 nm (E260). Herein, the extent of correlation between the E260 and the removal efficiency of the hazardous contaminants, endocrine disrupters and dioxins, were investigated using various treatment and river source waters. The detection of various types of hazardous contaminants using sophisticated analytical methods, such as high resolution gas chromatography (HRGC)/high resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC)/inductively coupled plasma (ICP)/mass spectrometry (MS), as well as various short-term bioassays, can require hours or even days for results to be obtained. The removal of the E260 correlated well with those of individual contaminants, such as endocrine disruptor chemicals and dioxins, with the various treatment processes employed. In the plots of the endocrine disrupters against the DOC/E260, a correlation was found with the endocrine activity of the Korean/Japanese river waters employed in this study.     

Developing the algorithm and device for automatic connection of an out-of-phase standby power-supply system without a disruption of load powering

The processes of switching from an AC (50/60 Hz) main power-supply system to a standlby system in the presence of different initial phases and a certain delay in switching are considered under the following loads: an asynchronous motor and a power transformer. A new device and algorithm for switching without time delay and, consequently, without load voltage surges are proposed. Switching of power-supply systems using the proposed device and the influence of the switching time on the capacity of the energy-storage unit of the device are considered. The potentialities of a multifunctional device for connecting a standby power-supply system are described.     

Modeling Power Supply Noise in Delay Testing

Excessive power supply noise during test can cause overkill. This article discusses two models for supply noise in delay testing and their application to test compaction. The proposed noise models avoid complicated power network analysis, making them much faster than existing power noise analysis tools. can cause performance degradation and     

United Kingdom EM gun programme

The authors review the progress in the RARDE (Royal Armament Research and Development Establishment) electromagnetic gun (REMGUN) program. They cover research on both railgun and LIA (linear induction accelerator) technology, including work on modeling, projectile/barrel interactions armatures, switching, and instrumentation. They also describe the major research facilities. Progress is reported in the identification and development of single-shot switches, integrated switch/barrel concepts, armatures and pulse power supplies as well as the integration of railgun components. LIA research has concentrated on launcher design and projectile/barrel interactions, highlighting the problems of pulse power systems for this form of electromagnetic launcher     

A 1320 nm experimental optical phase-locked loop

An experimental balanced optical second-order phase-locked loop constructed using 1320 nm diode laser pumped miniature Nd:YAG lasers is discussed. The loop is stable and has a phase error of less than 1.8° when the received signal power is -65 dBm or more. The phase error appears to be dominated by the lasers' frequency noise as long as the signal power is more than -60 dBm