Electromagnetic vibration energy harvesting using an improved Halbach array

This paper reports an electromagnetic vibration energy harvester using an improved Halbach array. A Halbach array is a specific arrangement of permanent magnets that concentrates the magnetic field on one side of the array while cancelling the field on the other side to almost zero. Previous research showed that although the Halbach array has higher magnetic field density compared to normal magnet layouts, its magnetic flux gradient is not as high. Thus, output powers of energy harvesters with Halbach arrays were found to be less than those with normal magnet layouts. This paper proposes an improved Halbach array that achieves both high magnetic field strength and magnetic flux gradient. Test results showed that the improved Halbach array can increase the output power of energy harvesters by a factor of seven compared to the previous Halbach design and by a factor of 1.5 compared to the normal configuration

Radio Source Heating in the ICM: The Example of Cygnus A

One of the most promising solutions for the cooling flow problem involves energy injection from the central AGN. However it is still not clear how collimated jets can heat the ICM at large scale, and very little is known concerning the effect of radio lobe expansion as they enter into pressure equilibrium with the surrounding cluster gas. Cygnus A is one of the best examples of a nearby powerful radio galaxy for which the synchrotron emitting plasma and thermal emitting intra-cluster medium can be mapped in fine detail, and previous observations have inferred possible shock structure at the location of the cocoon. We use new XMM-Newton observations of Cygnus A, in combination with deep Chandra observations, to measure the temperature of the intra-cluster medium around the expanding radio cavities. We investigate how inflation of the cavities may relate to shock heating of the intra-cluster gas, and whether such a mechanism is sufficient to provide enough energy to offset cooling to the extent observed.Comment: To appear in the Proceedings of "Heating vs. Cooling in Galaxies and Clusters of Galaxies", August 2006, Garching (Germany), Eds. H. Boehringer, G.W. Pratt, A. Finoguenov, P. Schuecker, Springer-Verlag series "ESO Astrophysics Symposia", p.101, in press. 8 pages, 3 multiple figure

Anisotropic Release of the Residual Zero-point Entropy in the Spin Ice Compound Dy2Ti2O7: Kagome-ice Behavior

We report the specific heat and entropy of single crystals of the spin ice compound Dy2Ti2O7 at temperatures down to 0.35 K. We apply magnetic fields along the four characteristic directions: [100], [110], [111] and [112]. Because of Ising anisotropy, we observe anisotropic release of the residual zero-point entropy, attributable to the difference in frustration dimensionality. In the high magnetic field along these four directions, the residual entropy is almost fully released and the activation entropy reaches Rln2. However, in the intermediate field region, the entropy in fields along the [111] direction is different from those for the other three field directions. For the [111] direction the frustration structure changes from that of three-dimensional(3D) pyrochlore to that of two-dimensional(2D) Kagome-like lattice with constraint due to the ice rule, leading to different values of zero-point entropy.Comment: 4 pages, 4 figures, to appear in Phys. Rev.

Order induced by dipolar interactions in a geometrically frustrated antiferromagnet

We study the classical Heisenberg model for spins on a pyrochlore lattice interacting via long range dipole-dipole forces and nearest neighbor exchange. Antiferromagnetic exchange alone is known not to induce ordering in this system. We analyze low temperature order resulting from the combined interactions, both by using a mean-field approach and by examining the energy cost of fluctuations about an ordered state. We discuss behavior as a function of the ratio of the dipolar and exchange interaction strengths and find two types of ordered phase. We relate our results to the recent experimental work and reproduce and extend the theoretical calculations on the pyrochlore compound, Gd$_2$Ti$_2$O$_7$, by Raju \textit{et al.}, Phys. Rev. B {\bf 59}, 14489 (1999).Comment: 5 pages, 5 figures, AMSLaTe

Human Immunodeficiency Virus (HIV)

Magnetic Resonance Imaging (MRI) for the evaluation of patients infected with human immunodeficiency virus (HIV), as with most other forms of intracranial inflammatory or infectious diseases, is a powerful though largely nonspecific diagnostic tool. For imaging of these complex patients with the varied and numerous pathologies they may harbor, the standard protocol is utilized to include gadolinium‐enhanced sequences. This unit presents optional imaging sequences, including magnetic resonance diffusion (dMRI), magnetic resonance perfusion (pMRI), and magnetic resonance spectroscopy (MRS), that can be employed should patient tolerance allow and if specific the clinical situation requires further clarification.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145277/1/cpmia0403.pd

Main technical differences in the processing of broilers: a comparison between slaughterhouses in Brazil and UK

Rapid technological advances in chicken processing in plants around the world have meant that different techniques are being employed regarding the slaughter’s flow process. This paper aimed to compare and contrast systems and practices in two large slaughterhouses—one in UK and the other in Brazil. Annotated observations were made during inspection visits to chicken slaughterhouses in the two countries between 2014 and 2016. Whilst there were similarities in the two systems, there are also clear differences. The Brazilian case is evidently adapted for a more tropical condition, rather than the temperate one in UK. The handling practices of birds used during transportation, waiting, stunning as well as pre-cooling differ in techniques employed and consequently likely their efficiencies. In UK, the practices are more geared towards water and energy saving. The difference in market conditions and the length of the respective supply chains also determine the type of primary packaging used in final products. Both countries adhere to similar rulings applied to slaughterhouses. However, in the Brazilian case, it tended to comply with mainly external market demands. In conclusion, managers in the Brazilian poultry system could consider looking into adopting some of the practices used in UK, such as cage/crate dimension which reduce bird’s lesions and bruises; the use of stunning by modified atmosphere and pre-cooling for resource efficiency reasons and improvement in animal welfare. Finally, when distances between sites of production and consumption are great such as in Brazil, the use of modified atmosphere technology could be also further explored to ensure better quality of the final product

Quality of refrigerated raw milk from buffalo cows (Bubalus bubalis bubalis) in different farms and seasons in Brazil

The present research aimed to examine the chemical and microbiological characteristics of refrigerated raw milk collected from buffalo-only dairy herds from different farms and seasons. Samples were collected from twelve farms producing buffalo milk, located in the Mideast region of São Paulo state, in Brazil, once a month throughout the dairy calendar year from 2011 to 2014. The analysis of fat, protein, lactose, dry extract, and total solids contents were carried out using Infrared Absorption. Residues for antimicrobial analysis were carried out using Delvo Test Kit technique, and both somatic cell count and standard plate count analysis were carried out using Flow Cytometry. The analysis of the chemical components as well as for the microbiological analysis of SPC proved to be statistically significant throughout the period. No antibiotic residues were found in the totality of the sample, hence indicating that the farmers complied with the current sanitary legislation in that country, as well as SCC; however, higher values were found for the SPC. Significant results for all parameters analyzed were found among the farms, indicating that price incentives paid for the quality of raw milk could be an alternative to dairy processing companies, favoring yield and quality of the final product

Photon-photon correlations and entanglement in doped photonic crystals

We consider a photonic crystal (PC) doped with four-level atoms whose intermediate transition is coupled near-resonantly with a photonic band-gap edge. We show that two photons, each coupled to a different atomic transition in such atoms, can manifest strong phase or amplitude correlations: One photon can induce a large phase shift on the other photon or trigger its absorption and thus operate as an ultrasensitive nonlinear photon-switch. These features allow the creation of entangled two-photon states and have unique advantages over previously considered media: (i) no control lasers are needed; (ii) the system parameters can be chosen to cause full two-photon entanglement via absorption; (iii) a number of PCs can be combined in a network.Comment: Modified, expanded text; added reference