Evolutions towards a new LSPR particle: Nano-sinusoid Progress in Electromagnetic Research (PIER)

This paper proposes a novel nano-sinusoid particle to be employed in enhanced localized surface plasmon resonance (LSPR) bio-sensing devices. Numerical investigations are carried out to demonstrate advantages o®ered by the proposed nano-particle on LSPR enhancement over other nano-particles including noble nano-triangles and nano-diamonds. Although nano-triangles exhibit high concentration of the electric ¯eld near their tips, when illuminated with a light polarized along the tip axis, they present only one hot spot at the vertex along the polarization direction. To create a structure with two hot spots, which is desired in bio-sensing applications, two nano-triangles can be put back-to-back. Therefore, a nano-diamond particle is obtained which exhibits two hot spots and presents higher enhancements than nano-triangles for the same resonant wavelength. The main drawback of the nano-diamonds is the °uctuation in their physical size-plasmon spectrum relationships, due to a high level of singularity as the result of their four sharp tip points. The proposed nano-sinusoid overcomes this disadvantage while maintaining the bene¯ts of having two hot spots and high enhancement

Are Food Subsidies Making Our Kids Fat? Tensions Between the Healthy Hunger-Free Kids Act and the Farm Bill

On December 15, 2010, President Obama signed the Healthy Hunger- Free Kids Act of 2010 (HHFKA)1 into law. It was hailed as a bipartisan success and a significant reform of childhood nutrition policy. Indeed, on its surface the law appears to make a significant shift away from the food paradigm of the past. However, upon closer examination, it fails to unwind the tangled connections between domestic eating habits and longstanding farm subsidies. This Article breaks new ground in several ways: First, it is one of the first essays in the emerging and underexplored field of food law, a crosssection of health law, law and society, environmental law, and administrative law; second, this is the first Article to look in-depth at the Healthy Hunger-Free Kids Act of 2010, which is in some ways the most radical iteration of the Child Nutrition Act2 and National School Lunch Act3 in twenty-five years; third, I offer a unique critique of this legislation by pointing out the tacit juxtaposition between it and longstanding farm subsidies, which are up for renewal and reconsideration next year; and finally, relying on both of these observations, I outline what Congress should do to effectively reform the current regulatory regime and address the critical public health issue of obesity. Specifically, I argue Congress must reallocate or eliminate certain food subsidies through farm bill reform, closely monitor the USDA’s exercise of discretion, limit loopholes relating to competitive foods, monitor potential preemption suits, reallocate the designation of dietary guidelines to a medical or health administrative agency, and allocate additional resources to the school meal infrastructure

A resonance tunable and durable LSPR nano-particle sensor : AL2O3 capped silver nano-disks

Localized surface plasmon resonance (LSPR) biosensors are employed to detect target biomolecules which have particular resonance wavelengths. Accordingly, tunability of the LSPR wavelength is essential in designing LSPR devices. LSPR devices employing silver nano-particles present better efficiencies than those using other noble metals such as gold; however, silver nano-particles are easily oxidized when they come in contact with liquids, which is inevitable in biosensing applications. To attain both durability and tunabilty in a LSPR biosensor, this paper proposes alumina (AL2O3) capped silver nano-disks. It is shown that through controlling the thickness of the cap, the LSPR resonance frequency can be finely tuned over a wide range; and moreover, the cap protects silver nano-particles from oxidation and high temperature.<br /

Developing lspr design guidelines

Applications of localized surface plasmon resonance (LSPR) such as surface enhanced Raman scattering (SERS) devices, biosensors, and nano-optics are growing. Investigating and understanding of the parameters that affect the LSPR spectrum is important for the design and fabrication of LSPR devices. This paper studies different parameters, including geometrical structures and light attributes, which affect the LSPR spectrum properties such as plasmon wavelength and enhancement factor. The paper also proposes a number of rules that should be considered in the design and fabrication of LSPR device

Polyethylene Oxide Nanofiber Production by Electrospinning

Electrospinning is an inexpensive technique that is used to produce nanofibers for a variety of applications. In electrospinning, a polymer solution is dispensed from a hypodermic-like syringe where an intense electric field attracts the solution to a collector while drawing the polymer into a very thin fiber. The diameter of the fiber can be controlled by tuning the process parameters such as the applied electric field, solution flow rate, distance between syringe tip and collector, and the collector geometry. In this paper we describe results from electrospinning poly(ethylene oxide) (PEO), a likely candidate for applications involving scaffolding for tissue engineering. The PEO nanofibers were fabricated from different polymer solution concentrations ranging from 14% - 22% (by weight). Each sample was then imaged using a scanning electron microscope. The morphology of the fibers produced from varying solution concentrations is discussed

Exploring failure modes of alumina scales on FeCrAl and FeNiCrAl alloys in a nitriding environment

Two high-temperature FeCrAl and FeNiCrAl alloys were exposed in a strongly nitriding environment at 900 \ub0C and the morphology of nitridation was studied. Quasi-in-situ experiments revealed that nitridation started at specific surface sites directly related to the alloy microstructure where the alumina scale was permeable to nitrogen. FeCrAl alloy grains with (112) orientation formed outward-growing alumina scales and were susceptible to nitridation. Outward-growing scales and substrate nitridation was also observed at chromium carbide precipitates in the FeNiCrAl alloy. Both alloys suffered nitridation at reactive element-rich (Y and Zr) inclusions larger than a certain critical size. The latter type of attack is caused by cracks and pores in the scale. The findings open new avenues of research for developing the next generation of high temperature alloys with superior properties

Beyond Spheroids and Discs: Classifications of CANDELS Galaxy Structure at 1.4 < z < 2 via Principal Component Analysis

Important but rare and subtle processes driving galaxy morphology and star-formation may be missed by traditional spiral, elliptical, irregular or S\'ersic bulge/disk classifications. To overcome this limitation, we use a principal component analysis of non-parametric morphological indicators (concentration, asymmetry, Gini coefficient, $M_{20}$, multi-mode, intensity and deviation) measured at rest-frame $B$-band (corresponding to HST/WFC3 F125W at 1.4 $10^{10} M_{\odot}$) galaxy morphologies. Principal component analysis (PCA) quantifies the correlations between these morphological indicators and determines the relative importance of each. The first three principal components (PCs) capture $\sim$75 per cent of the variance inherent to our sample. We interpret the first principal component (PC) as bulge strength, the second PC as dominated by concentration and the third PC as dominated by asymmetry. Both PC1 and PC2 correlate with the visual appearance of a central bulge and predict galaxy quiescence. PC1 is a better predictor of quenching than stellar mass, as as good as other structural indicators (S\'ersic-n or compactness). We divide the PCA results into groups using an agglomerative hierarchical clustering method. Unlike S\'ersic, this classification scheme separates compact galaxies from larger, smooth proto-elliptical systems, and star-forming disk-dominated clumpy galaxies from star-forming bulge-dominated asymmetric galaxies. Distinguishing between these galaxy structural types in a quantitative manner is an important step towards understanding the connections between morphology, galaxy assembly and star-formation.Comment: 31 pages, 24 figures, accepted for publication in MNRA