Neuromagnetic localization using magnetic resonance images

Ionic flow associated with neural activation of the brain produces a magnetic field, called the neuromagnetic field, that can be measured outside the head using a highly sensitive superconducting quantum interference device (SQUID)-based neuromagnetometer. Under certain conditions, the sources producing the neuromagnetic field can be localized from a sampling of the neuromagnetic field. Neuromagnetic measurements alone, however, do not contain sufficient information to visualize brain structure. Thus, it is necessary to combine neuromagnetic localization with an anatomical imaging technique such as magnetic resonance imaging (MRI) to visualize both function and anatomy in vivo. Using experimentally measured human neuromagnetic fields and magnetic resonance images, the authors have developed a technique to register accurately these two modalities and have applied the registration procedure to portray the spatiotemporal distribution of neural activity evoked by auditory stimulation.     

Water table fluctuation with a random initial condition

The nonlinear Boussinesq equation is used to understand water table fluctuations in various ditch drainage problems. An approximate solution of this equation with a random initial condition and deterministic boundary conditions, recharge rate and aquifer parameters has been developed to predict a transient water table in a ditch-drainage system. The effects of uncertainty in the initial condition on the water table are illustrated with the help of a synthetic example. These results would find applications in ditch-drainage design.Notation A / tanh t - a lower value of the random variable representing the initial water table height at the mid point - a+b Upper value of the random variable representing the initial water table height at the midpoint - B tanh t - C 4/ - h variable water table height - h mean of the variable water table height - h _m variable water table height at the mid point - h _m mean of the variable water table height at the mid point - K hydraulic conductivity - L half spacing between the ditches - m ₀ initial water table height at the mid point - N Uniform rate of recharge - S specific yield - t time of observation - x distance measured from the ditch boundary - (4/SL)(NK)^1/2 - (L/4)(N/K)^1/2 - dummy integral variable     

Influence of ageing treatment on work hardening behaviour of a Ni-base superalloy

Thus it may be summarised that work hardening behaviour of the alloy superni 263 can not be analysed using the simple power law equation. The work hardening behaviour is satisfactorily analysed using the modified power law equation (Ludwigson equation). There is systematic variation in the different work hardening parameters K₁, n₁, K₂, n₂ and _C with the period of ageing at 800 °C. The drastic lowering of the parameters n₁ and e_up, from ageing even for a short duration, suggests that this material should be formed in fully solution treated condition and any precipitation of γ′ must be avoided for good formability.     

Application of Machine Learning Algorithms With and Without Principal Component Analysis for the Design of New Multiphase High Entropy Alloys

Metallurgical and Materials Transactions A - The design of high entropy alloys (HEAs) can be accelerated using machine learning (ML) algorithms. In the current study, the design parameter’s...     

Effect of copper chelates on U.V. stability of butyl rubber and SBR rubber

An investigation of the photo-oxidative degradation and stabilization of IIR and SBR in the temperature range of 258 to 313°K in air with a monochromatic light of 366 nm in the absence and presence of various concentrations of the different copper chelates has been described. The stabilizer performance in IIR and SBR was accessed by carbonyl index and quantum yield measurements. The changes of IIR and SBR during the irradiation with an ultra-violet light (366 nm) have been conducted by viscometrically and actinometric techniques. Irradiations were conducted on the films at 0, 2, 4, 6, 8, 10, 12 and 14 hours and various parameters were obtained.     

Graft-copolymerization of starch with acrylamide,II. Thermal behaviour of graft copolymers

Thermal behaviour of starch-graft-polyacrylamide (S-g-PAM) copolymers was evaluated. Grafting of polyacrylamide onto starch lowers the initial decomposition temperature. However, the over-all stability as assessed by the shape of thermogravimetric curve and integral procedural decomposition temperature increased with an increase in % graft-on.     

ESTIMATION OF VAPOR PRESSURES OF ORGANIC NITROGEN AND SULFUR COMPOUNDS BY A GROUP-CONTRIBUTION METHOD

The group-contribution method for vapor pressures of hydrocarbons and organic compounds containing nitrogen or sulfur, based on the kinetic theory of fluids, is revised and extended to include new groups containing nitrogen or sulfur. Good representation is obtained for vapor pressure data in the region 1.30-270 kPa. The method may be used to estimate vapor pressures and enthalpies of vaporization for those organic fluids containing nitrogen or sulfur, where no experimental data are available.     

Response of wheat (Triticum aestivum) and pearl-millet (Pennistum americanum) to zinc fertilizers on two soils

Responses of ZnSO₄, Zn₃ (PO₄)₂ · 4H₂O, ZnO, ZnNH₄PO₃ · 2H₂O and zincated superphosphate were studied on wheat (Triticum aestivum) and pearl-millet (Pennistem americanum) in Balsamand sand (Ustipsament) and Ladwa fine loam (Typic Camborthids). In Balsamand sand all Zn fertilizers increased wheat and pearl-milllet grain yield significantly over control but ZnNH₄ PO₄ · 2H₂O and zincated super were the best sources. Straw yield was also highest due to zincated super and ZnNH₄PO₄ · 2H₂O applications. Zinc sulphate was significantly inferior to zincated super and ZnNH₄PO₄ · 2H₂O. In Ladwa fine loam, all fertilizers gave significantly higher grain yield of wheat and pearl-millet than control except ZnO in pearl-millet. Highest yield in this soil was obtained by ZnSO₄ · 7H₂O followed by ZnNH₄ PO₄ · 2H₂O and then zincated super.In Balsamand sand, the Zn fertilizers significantly increased the Zn concentration and Zn uptake of wheat grain. In pearl-millet, only Zn uptake was increased significantly with Zn fertilizers. Zincated super gave highest Zn uptake.The concentration of P in wheat grain was increased by Zn fertilizers in Balsamand sand, and also in pearl-millet where zincated super and ZnNH₄PO₄ were most effective in increasing the P content.When Zn fertilizers were applied to preceding pearl-millet the effect on succeeding wheat crop were in the same order as direct application of Zn fertilizers. Zincated super was the best and ZnO worst with respect to wheat grain and straw yield and uptake of Zn and P.     

Diffusion coefficient in polymer solutions

Molecular diffusivity of a solute in a solvent may be determined by measuring the extent of dispersion of solute in solvent flowing in a straight circular tube under the conditions of laminar flow. This simple and rapid method for determination of molecular diffusivity in aquous polymer solutions is discussed. Experimental results show a substantial reduction in the solute diffusivity with increase in polymer concentration.