140 research outputs found
Magnetoelectric properties of 500 nm Cr2O3 films
The linear magnetoelectric effect was measured in 500 nm Cr2O3 films grown by
rf sputtering on Al2O3 substrates between top and bottom thin film Pt
electrodes. Magnetoelectric susceptibility was measured directly by applying an
AC electric field and measuring the induced AC magnetic moment using
superconducting quantum interference device magnetometry. A linear dependence
of the induced AC magnetic moment on the AC electric field amplitude was found.
The temperature dependence of the magnetoelectric susceptibility agreed
qualitatively and quantitatively with prior measurements of bulk single
crystals, but the characteristic temperatures of the film were lower than those
of single crystals. It was also possible to reverse the sign of the
magnetoelectric susceptibility by reversing the sign of the magnetic field
applied during cooling through the N\'eel temperature. A competition between
total magnetoelectric and Zeeman energies is proposed to explain the difference
between film and bulk Cr2O3 regarding the cooling field dependence of the
magnetoelectric effect.Comment: accepted at Physical Review
Energy Conservation in University bu Ildings by Energy Pattern Analysis Using Clustering Technique
The energy demand of the building sector is increasing rapidly, driven by the improved access to energy in developing countries, greater ownership and use of energy-consuming devices, and rapid growth in building floor area. Energy demands in the building sector account for more than 30% of the total energy consumption and more than 55% of the global electricity demand. Efforts to develop sustainable buildings are progressing but are still not keeping up with the growing building sector and the rising demand for energy. Analyzing the energy consumption pattern of the buildings and planning for energy conservation in existing buildings are essential. In this research we proposed a method to analzse the energy pattern of university buildings using K-means clustering method. Energy consumption in Science, non-science and office buildings of university is analyzed and their respective base energy, energy consumption due to human activities and air-conditioning energy consumption is calculated. The proposed method is successful in classifying the energy consumption and will prove to be helpful in the planning of energy conservation in buildings
Magnetoelectric properties of 500-nm Cr2O3 films
The linear magnetoelectric effect was measured in 500-nm Cr2O3 films grown by radio frequency sputtering on Al2O3 substrates between top and bottom thin film Pt electrodes. Magnetoelectric susceptibility was measured directly by applying an alternating current (ac) electric field and measuring the induced ac magnetic moment using superconducting quantum interference device magnetometry. A linear dependence of the induced ac magnetic moment on the ac electric field amplitude was found. The temperature dependence of the magnetoelectric susceptibility agreed qualitatively and quantitatively with prior measurements of bulk single crystals, but the characteristic temperatures of the film were lower than those of single crystals. It was also possible to reverse the sign of the magnetoelectric susceptibility by reversing the sign of the magnetic field applied during cooling through the Néel temperature. A competition between total magnetoelectric and Zeeman energies is proposed to explain the difference between film and bulk Cr2O3 regarding the cooling field dependence of the magnetoelectric effect
TSUNAMI: an antisense method to phenocopy splicing-associated diseases in animals
Antisense oligonucleotides (ASOs) are versatile molecules that can be designed to specifically alter splicing patterns of target pre-mRNAs. Here we exploit this feature to phenocopy a genetic disease. Spinal muscular atrophy (SMA) is a motor neuron disease caused by loss-of-function mutations in the SMN1 gene. The related SMN2 gene expresses suboptimal levels of functional SMN protein due to alternative splicing that skips exon 7; correcting this defect-e.g., with ASOs-is a promising therapeutic approach. We describe the use of ASOs that exacerbate SMN2 missplicing and phenocopy SMA in a dose-dependent manner when administered to transgenic Smn(-/-) mice. Intracerebroventricular ASO injection in neonatal mice recapitulates SMA-like progressive motor dysfunction, growth impairment, and shortened life span, with alpha-motor neuron loss and abnormal neuromuscular junctions. These SMA-like phenotypes are prevented by a therapeutic ASO that restores correct SMN2 splicing. We uncovered starvation-induced splicing changes, particularly in SMN2, which likely accelerate disease progression. These results constitute proof of principle that ASOs designed to cause sustained splicing defects can be used to induce pathogenesis and rapidly and accurately model splicing-associated diseases in animals. This approach allows the dissection of pathogenesis mechanisms, including spatial and temporal features of disease onset and progression, as well as testing of candidate therapeutics
New Samarium and Neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field
Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near
zero net magnetization with substitutions of 6 to 9 atomic percent of Nd and 25
atomic percent of Gd, respectively. The notion of magnetic compensation in them
is also elucidated by the crossover of zero magnetization axis at low magnetic
fields (less than 103 Oe) and field-induced reversal in the orientation of the
magnetic moments of the dissimilar rare earth ions at higher magnetic fields.
These magnetically ordered materials with no net magnetization and appreciable
conduction electron polarization display an attribute of an exchange bias
field, which can be tuned. The attractively high magnetic ordering temperatures
of about 270 K, underscore the importance of these materials for potential
applications in spintronics.Comment: 6 page text + 5 figure
Search for the Magnetic Monopole at a Magnetoelectric Surface
We show, by solving Maxwell’s equations, that an electric charge on the surface of a slab of a linear magnetoelectric material generates an image magnetic monopole below the surface provided that the magnetoelectric has a diagonal component in its magnetoelectric response. The image monopole, in turn, generates an ideal monopolar magnetic field outside of the slab. Using realistic values of the electric and magnetic field susceptibilities, we calculate the magnitude of the effect for the prototypical magnetoelectric material Cr2O3. We use low-energy muon spin rotation to measure the strength of the magnetic field generated by charged muons as a function of their distance from the surface of a Cr2O3 film and show that the results are consistent with the existence of the monopole. We discuss other possible routes to detecting the monopolar field, and show that, while the predicted monopolar field generated by Cr2O3 is above the detection limit for standard magnetic force microscopy, the detection of the field using this technique is prevented by surface charging effects
Seaweed intake and blood pressure levels in healthy pre-school Japanese children
<p>Abstract</p> <p>Background</p> <p>Few studies have examined whether dietary factors might affect blood pressure in children. We purposed to investigate whether seaweed intake is associated with blood pressure level among Japanese preschool children.</p> <p>Methods</p> <p>The design of the study was cross-sectional and it was conducted in autumn 2006. Subjects were healthy preschoolers aged 3-6 years in Aichi, Japan. Blood pressure and pulse were measured once by an automated sphygmomanometer, which uses oscillometric methods. Dietary data, including seaweed intake, were assessed using 3-day dietary records covering 2 consecutive weekdays and 1 weekend day. Of a total of 533 children, 459 (86.1 percent) agreed to be enrolled in our study. Finally, blood pressure measurement, complete dietary records and parent-reported height and weight were obtained for 223 boys and 194 girls.</p> <p>Results</p> <p>When we examined Spearman's correlation coefficients, seaweed intake was significantly negatively related to systolic blood pressure in girls (<it>P </it>= 0.008). In the one-way analysis of covariance for blood pressure and pulse after adjustments for age and BMI, the boys with the lowest, middle and highest tertiles of seaweed intake had diastolic blood pressure readings of 62.8, 59.3 and 59.6 mmHg, respectively (<it>P </it>= 0.11, trend <it>P </it>= 0.038). Girls with higher seaweed intake had significantly lower systolic blood pressure readings (102.4, 99.2 and 96.9 mmHg for girls with the lowest, middle and highest tertiles of seaweed intake, respectively; <it>P </it>= 0.037, trend <it>P </it>= 0.030).</p> <p>Conclusion</p> <p>Our study showed that seaweed intake was negatively related to diastolic blood pressure in boys and to systolic blood pressure in girls. This suggests that seaweed might have beneficial effects on blood pressure among children.</p
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