Room Temperature Ferromagnetism in Co-doped CuAlO2 Nanofibers Fabricated by Electrospinning

One-dimensional, diluted magnetic semiconductor nanofibers have attracted increasing attention for their unique magnetic properties, large specific surface area, and high porosity. These qualities lead to excellent performance in magneto-optical devices, magnetic resonance imaging, ferrofluids and magnetic separation. The purpose of this study is to fabricate P-type one dimensional CuAlO2-based diluted magnetic semiconductor nanofibers. First, we fabricated Cu Al0.95Co0.05O2 nanofibers with an average diameter of 1 μm with the electrospinning method. The annealed nanofibers were thermally treated at a temperature of 1 100 ℃ and then shrunk to a diameter of about 650 nm. We used X-ray diffraction measurements and Raman spectra to confirm that the Cu Al0.95Co0.05O2 nanofibers had a single impurity free delafossite phase. The X-ray photoelectron spectroscopy analysis indicates that Co was present in the +2 oxidation state, resulting in an room temperature ferromagnetism in the Cu Al0.95Co0.05O2 fiber. This contrasts with nonmagnetism in pristine CuAlO2 fiber. The coercivity(Hc) value of 65.26 Oe and approximate saturation magnetization(Ms) of 0.012 emu/g demonstrate good evidence of ferromagnetism at room temperature for Cu Al0.95Co0.05O2 nanofibers.     

Hopping transport in the space-charge region of p-n structures with InGaN/GaN QWs as a source of excess 1/f noise and efficiency droop in LEDs

Semiconductors - It is shown that the emission efficiency and the 1/f noise level in light-emitting diodes with InGaN/GaN quantum wells correlate with how the differential resistance of a diode...     

Operational Safety of the Zagorsk PSP After Leveling of Its Powerhouse

Power Technology and Engineering - The work done on the test site to ensure the operational safety of the powerhouse of the Zagorsk PSP-2 after its leveling is described. The controlled...     

An experimental approach towards increasing mechanical durability of extruded fish feed in the drying process

Mechanical durability of extruded fish feed must be optimized to lower economic losses as well as emission of organic matter to aquatic environments. The glass transition hypothesis for viscoelastic biopolymers is demonstrated and confirmed experimentally to be valid for extruded fish feed pellets. It is proposed and demonstrated that it is important to avoid early glass transition onset, to optimize the obtained mechanical durability. From the proposed glass transition hypothesis, immediate process relevance to the pre-drying transport mechanism is demonstrated. Furthermore, measured mechanical durability is found to range from 1.5 to 5.0% loss, for different combinations of drying parameters.     

Cooperative Communication Enabled Cognitive Radio in a Home-Care Application

Wireless Personal Communications - In this paper, cooperative communication (CC) assisted cognitive wireless sensor network (CWSN) is presented for monitoring health and activity of an end-user in...     

Household endotoxin reduction in the Louisa Environmental Intervention Project for rural childhood asthma

Endotoxin exacerbates asthma. We designed the Louisa Environmental Intervention Project (LEIP) and assessed its effectiveness in reducing household endotoxin and improving asthma symptoms in rural Iowa children. Asthmatic school children (N = 104 from 89 homes) of Louisa and Keokuk counties in Iowa (aged 5-14 years) were recruited and block-randomized to receive extensive (education + professional cleaning) or educational interventions. Environmental sampling collection and respiratory survey administration were done at baseline and during three follow-up visits. Mixed-model analyses were used to assess the effect of the intervention on endotoxin levels and asthma symptoms in the main analysis and of endotoxin reduction on asthma symptoms in exploratory analysis. In the extensive intervention group, dust endotoxin load was significantly reduced in post-intervention visits. The extensive compared with the educational intervention was associated with significantly decreased dust endotoxin load in farm homes and less frequent nighttime asthma symptoms. In exploratory analysis, dust endotoxin load reduction from baseline was associated with lower total asthma symptoms score (Odds ratio: 0.52, 95% confidence interval: 0.29-0.92). In conclusion, the LEIP intervention reduced household dust endotoxin and improved asthma symptoms. However, endotoxin reductions were not sustained post-intervention by residents.