Four-wave mixing (FWM) based parametric amplification in optical microfibers (OMFs) is demonstrated over a wavelength range of over 1000 nm by exploiting their tailorable dispersion characteristics to achieve phase matching. Simulations indicate that for any set of wavelengths satisfying the FWM energy conservation condition there are two diameters at which phase matching in the fundamental mod...

The purpose of this study was to construct a flowmeter that could accurately measure the hydraulic permeability of electrospun fibrinogen scaffolds, providing insight into the transport properties of electrospun scaffolds while making the measurement of their topographical features (fiber diameter and pore size) more accurate. Three different concentrations of fibrinogen were used (100, 120, an...

This study compares limb lengths and joint diameters in the skeletons of six macaque species (Macaca assamensis, M. fascicularis, M. fuscata, M. mulatta, M. nemestrina, and M. thibetana) from a broad range of habitats and climates in order to test whether ambient temperatures, latitude, and altitude influence interspecific variation in limb morphology in this widely dispersed genus. Analysis of...

Flexible and semi-rigid heat-shrinkable tubes (HSTs) have been used in thousands of applications, and here rigid high temperature HSTs are reported for the first time. These rigid HSTs are prepared with shape memory polyimides possessing glass transition temperatures (Tgs) from 182 to 295 °C, and the relationships between Tg and their molecular structures are studied. The polyimide HSTs (PIHSTs...

How do real graphs evolve over time? What are “normal” growth patterns in social, technological, and information networks? Many studies have discovered patterns in static graphs, identifying properties in a single snapshot of a large network, or in a very small number of snapshots; these include heavy tails for inand out-degree distributions, communities, small-world phenomena, and others. Howe...

In this paper we construct trees having only integer eigenvalues with arbitrarily large diameters. In fact, we prove that for every set S of positive integers there exists a tree whose positive eigenvalues are exactly the elements of S. If the set S is different from the set {1} then the constructed tree will have diameter 2|S|.

We present a surprisingly short proof that for any continuous map f : Rn → Rm, if n > m, then there exists no bound on the diameter of fibers of f . Moreover, we show that when m = 1, the union of small fibers of f is bounded; when m > 1, the union of small fibers need not be bounded. Applications to data analysis are considered. High-dimensional data sets are often difficult to analyze directl...

Background/Purpose. Recent findings suggest that an objective assessment of retinal vessel caliber from fundus photographs provide information about the association of microvascular characteristics with macrovascular disease. Current methods used to quantify retinal vessel caliber, introduced by Parr(1,2) and Hubbard,(3) are not independent of scale and are affected by the number of vessels. To...