Extremal functions for the anisotropic Sobolev inequalities

The existence of multiple nonnegative solutions to the anisotropic critical problem - \sum_{i=1}^{N} \frac{\partial}{\partial x_i} (| \frac{\partial u}{\partial x_i} |^{p_i-2} \frac{\partial u}{\partial x_i}) = |u|^{p^*-2} u {in} \mathbb{R}^N is proved in suitable anisotropic Sobolev spaces. The solutions correspond to extremal functions of a certain best Sobolev constant. The main tool in our study is an adaptation of the well-known concentration-compactness lemma of P.-L. Lions to anisotropic operators. Futhermore, we show that the set of nontrival solutions \calS is included in $L^\infty(\R^N)$ and is located outside of a ball of radius $\tau >0$ in $L^{p^*}(\R^N)$

The effect of strain and temperature on the critical current density of high-field superconductors

A J(B,ϵ) probe has been designed and built to measure the critical current density, J(_c), versus strain on short superconducting wires and tapes. Measurements can be made from 2K to 4.2K in high magnetic fields in our 17T magnet system and at 77K for strains up to ±1.0%.The effect of strain on J(_c) has been measured on a 0.37mm diameter Nb(_3)Sn wire at 4.2K and 2.9K from l0T up to 14T. The compressive pre-strain of the wire measured at 4.2K is found to be about 0.3%. At 4.2K, the value of B(_c2) maximum is 19.6T and at 2.9K is 21.2T. The functional form of the flux pinning of the sample at 4.2K can be expressed as F(_p)=4.20±0.57xl0(^8)[B(_c2)(ϵ)](^1.67±0.7b(^1/2)(l-b)(^2); and for the sample at 2.9K it is F(_p)=1.37±0.05xl0(^10)[B(_c2)(ϵ)](^0.54±0.16b(^1/2)(l-b)(^2). From temperature scaling, the functional form is F(_p)=3.63 ±0.62xl0(^8)[B(_c2)(T)](^1.72±1.3)b(^1/2)(l-b)(^2). The difference in the values of n between strain scaling and temperature scaling shows that n only parameterises the change in J(_c) with change in strain or temperature. The effect of strain on J(_c) has been measured on five short sections of an Ag-sheathed BSCCO(2223) tape at 4.2K and in magnetic fields up to 12T. J(_c) degradation starts to occur between 0.18%-0.25% strain. The appearance of secondary peaks in the critical current distribution is attributed to inter-grain J(_c) and infra-grain J(_c). J(_c) measurements have been made on bulk PbMo(_6)S(_8)(PMS) samples. J(_c) increased by a factor of «7 when the sample was hot isostatically pressed(HIP). Measurements have also been made on series of HIP'ed gadolinium(Gd) doped Pbi(_1-x)Gd(_x)Mo(_6)S(_8) samples. The highest T(_c) value is 14.55K when x=0.1. The highest J(_c) is when x=0.2. The irreversibility field B(_irr)(0) from J(_c) measurements has been calculated to be 53.9T, 45.5T, 34.IT and 33.5T for the x=0, 0.1,0.2 and 0.3 samples, respectively

The Design and Development of an Automatic Guiding System for a Tractor

Mechanization and Automation are very fashionable words in present day Agriculture. Both imply a reduction in the amount of human effort necessary to achieve certain ends, and to accept the need for either of them is to assume that it will lead to some financial gain. Automation as applied to Agriculture is to improve many limited factors which affect the final yield of any agricultural crop. One of these factors, the mechanical operation, requires considerable care and attention to more nearly insure maximum yield and high quality. Numerous methods have been adopted through research and development to minimize field losses of a crop and to improve the quality of product with the use of more adaptable and accurate machines. As such, the objective of this study was: 1. To design, develop, and construct an automatic steering device which would enable a tractor to guide itself down the crop row accurately. The system was to be designed in a manner that would make it possible for the tractor to be used for a variety of crops with little or no change in the automatic steering components. 2. To design a system which could be justified economically where labor is scarce and expensive or unskilled, or where the tractors are operated in hazardous conditions

INCIDENCE OF STAPHYLOCOCCUS AUREUS AND COAGULASE POSITIVE STAPH. AUREUS IN RAW MILK IN KOSOVO

The presence study was conducted to determine the presence of Staphylococcus aureus and coagulase positive S. aureus in raw milk collected from different localities in Kosovo. We have examined 55 samples of raw milk cow taken from cattle farms. The Staphylococcus aureus was isolated in Baird Parker agar where typical and atypical colonies were selected and submitted to coagulase and complementary tests. Out of 55 samples of raw milk studied, 17 showed contamination by Staphylococcus aureus corresponding to 31% of the samples being contaminated. Out of 17 samples showed contamination by S. aureus, 5 of them were coagulase positive S. aureus or 29 % (or 9 % of total samples analyzed). Results clearly suggested a possibility of potential public health threat of Staphylococcus aureus resulting from contamination of milk with pathogenic bacteria is mainly due to unhygienic processing, handling and unhygienic environment

Simultaneous effect of temperature and site altitude on generators output

The effect of environmental conditions of the site must be considered as one of the most important aspects of designing generators as well as theoretic calculations and considerations. The real amounts which are measurable on the sites under real conditions are usually different from the rated values of the generators. In this paper we exerted this consideration and a typical model of generator produced by Ansaldo Energia was selected and studied. The material of the generator application guide and the measured values on site are used to get related curves of the environmental conditions effect, such as the effect the site altitude and the ambient temperature, on generator rated values. The practical and measured values of this model of generator which has been installed on Parand and Oroumieh sites in Iran are used for verification of the results of this paper and the related error is calculated. We claim this technical research has not been done before with such mentioned considerations and necessities. This paper gives the necessary instruction to evaluate the applicability and the generator characteristic data at different operating conditions (load, voltage, power factor, site and cooling condition). This study enables the designer to evaluate the generator behavior under the customer requirements and environmental conditions as well as to prepare the necessary proposed documentation for the client. © 2011 Praise Worthy Prize S.r.l. - All rights reserved

Semi-Empirical Model to Estimate the Solubility of CO2 NaCl Brine in Conditions Representative of CO2 Sequestration

Peer reviewedPublisher PD

Repetitive Transcranial Magnetic Stimulation Affects behavior by Biasing Endogenous Cortical Oscillations

A governing assumption about repetitive transcranial magnetic stimulation (rTMS) has been that it interferes with task-related neuronal activity – in effect, by “injecting noise” into the brain – and thereby disrupts behavior. Recent reports of rTMS-produced behavioral enhancement, however, call this assumption into question. We investigated the neurophysiological effects of rTMS delivered during the delay period of a visual working memory task by simultaneously recording brain activity with electroencephalography (EEG). Subjects performed visual working memory for locations or for shapes, and in half the trials a 10-Hz train of rTMS was delivered to the superior parietal lobule (SPL) or a control brain area. The wide range of individual differences in the effects of rTMS on task accuracy, from improvement to impairment, was predicted by individual differences in the effect of rTMS on power in the alpha-band of the EEG (∼10 Hz): a decrease in alpha-band power corresponded to improved performance, whereas an increase in alpha-band power corresponded to the opposite. The EEG effect was localized to cortical sources encompassing the frontal eye fields and the intraparietal sulcus, and was specific to task (location, but not object memory) and to rTMS target (SPL, not control area). Furthermore, for the same task condition, rTMS-induced changes in cross-frequency phase synchrony between alpha- and gamma-band (>40 Hz) oscillations predicted changes in behavior. These results suggest that alpha-band oscillations play an active role cognitive processes and do not simply reflect absence of processing. Furthermore, this study shows that the complex effects of rTMS on behavior can result from biasing endogenous patterns of network-level oscillations