A chaotic regime of internal precession in3He-B

We have found a chaotic regime of counter-motion of the normal and superfluid magnetizations in³He-B. It takes place under conditions corresponding to the experiments with catastrophic relaxation. We study a spatially homogeneous regime of the magnetization's precession by employing a numerical simulation of the Leggett-Takagi theory, and show that there is a topological reconstruction of the spin dynamics that brings about a chaotic regime of Arnold diffusion. It is important that the regime, which takes place owing to the sophisticated nature of the Leggett-Takagi equations, does not require an external driving force.     

Dielectric spectroscopy of MgTiO3-based ceramics in the 109–1014Hz region

Magnesium titanate (MgTiO₃) powder was prepared by a chemical route (Pechini method) and different dopants were added to prepare several compositions. These pure and doped compositions were sintered in air and dense ceramics were obtained. The pure MgTiO₃ samples were also subjected to different heat treatments during sintering. Complex permittivity spectra of ceramic samples were determined by various techniques in the 10⁹–10¹⁴ Hz range. These techniques included infrared spectroscopy in transmission and reflectivity modes and microwave dielectric measurements. Extrapolation to microwave frequencies from infrared data, according to the proportionality (v) v, agrees quite well with the microwave data measured at 8 GHz and it is a useful procedure to estimate intrinsic microwave losses. Fast cooling from high temperatures of MgTiO₃ samples increased dielectric loss, probably due to a structural disorder. Dopants have two types of effect depending on whether they form a distinct second phase or a solid solution with MgTiO₃. In this last case intrinsic losses are strongly affected.     

Open-type miniature heat pipes

The hypothesis that systems of thermoregulation, similar to open-type micro heat pipes, exist in nature (soils, living organisms, plants) and in a number of technological processes (drying, thermodynamic cycles on solid adsorbents) is considered. The hydrodynamics and heat transfer in such thermoregulation systems differ from the hydrodynamics and heat transfer in classical heat pipes, since their geometrical dimensions are extremely small (dozens of microns), adhesion forces are powerful, the effect of the field of capillary and gravitational forces is significant, and strong interaction between counter-current flows of vapor and liquid takes place.Academic Scientific Complex A. V. Luikov Heat and Mass Transfer Institute, Academy of Sciences of Belarus, Minsk. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 65, No. 1, July, 1993.     

'Top 10' LIS vendors jockey for position

The laboratory information system market remains volatile despite a "flattening out" in overall sales, says industry consultant and analyst Sheldon I. Dorenfest. Vendors that were giants just a few years ago have been felled by smaller competitors, but no company can afford to rest easy in its current position.     

Interfacing industrial R&A equipment using Matlab

We present a toolbox that enables access to real robotics and automation (R&A) equipment from the MATLAB shell. If used in conjunction with a robotics toolbox, it will extend significantly their application, i.e., besides robotic simulation and data analysis, the user can interact online with the equipment he or she is using. This article briefly presents the software architecture adopted and how it was used to generate the MATLAB MEX files presented. It then exemplifies application to two types of equipment, complemented with a generic manipulation example using a robotic gripper. The utilization of this tool with force control experiments is also briefly explored     

More hype than Internet bytes for online ERP

The claim that the network is the computer remains valid, but nowadays, the Internet is regarded as the enterprise's network. Corporations continue to look for cost-effective solutions that let them deploy technology beyond their organization's network using the Internet, even for business-critical applications such as enterprise resource planning (ERP). There's an enormous push to look at every application category and make it Internet accessible. Several forces are driving this trend: among them the move to e-commerce and corporate desires to share information instantly with colleagues, business partners, and/or suppliers. ERP systems can let far-flung users read information via a browser in Web formats, such as HTML (Hypertext Markup Language), PDF (portable document format), or plain text. This makes it easier for users of all sophistication levels to get critical information instantly     

Fluorescence methods for determination of temperature in fuel sprays

Fluorescent additives which allow the determination of droplet temperatures in hydrocarbon fuel sprays have been developed. These systems, which exploit the chemistry of organic exciplexes; should make possible the determination of droplet temperatures within 1 degree C. Two specific systems are described: 3,10-dicyanophenanthrene/diethylaniline over the 20-135 degrees C range, and naphthalene/tetramethyl-p-phenylene diamine over the 140-265 degrees C range. These additives should allow 2-D real-time nonintrusive visualization of the droplet temperatures in an evolving fuel spray.     

Specific heat and magnetization of superconducting niobium in the mixed state

The thermodynamics of the mixed state of niobium is reconsidered. Critical fieldsH _c (t),H _c1(t),and H _c2(t), Maki parameters ₁ and ₂, magnetization, and specific heat are measured with a computer-controlled magnetometer and calorimeter. The results show quantitative discrepancies with the isotropic Gorkov-Brandt theory over almost the whole mixed state. Computations based on Fermi surface anisotropy using a scaling ofH _c2 provide a much better agreement with the experimental magnetization curves already in the limit of weak nonlocality, thus suggesting a numerical evaluation of the anisotropic terms in the Gorkov-Brandt theory.