We report a simple method to produce foams and emulsions of extraordinary stability by using hydrophobic cellulose microparticles, which are formed in situ by a liquid-liquid dispersion technique. The hydrophobic cellulose derivative, hypromellose phthalate (HP), was initially dissolved in water-miscible solvents such as acetone and ethanol/water mixtures. As these HP stock solutions were sheared in aqueous media, micron sized cellulose particles formed by the solvent attrition. We also designed and investigated an effective and simple process for making HP particles without any organic solvents, where both the solvent and antisolvent were aqueous buffer solutions at different pH. Consequently, the HP particles adsorbed onto the water/air or water/oil interfaces created during shear blending, resulting in highly stable foams or foam/emulsions. The formation of HP particles and their ability for short-term and long-term stabilization of interfaces strongly depended on the HP concentration in stock solutions, as well as the solvent chemistry of both stock solutions and continuous phase media. Some foams and emulsion samples formed in the presence of ca. 1 wt% HP were stable for months. This new class of nontoxic inexpensive cellulose-based particle stabilizers has the potential to substitute conventional synthetic surfactants, especially in edible, pharmaceutical and biodegradable products.

The length-fractionation of shortened (250 to 25 nm), zwitterion-functionalized, single wall carbon nanotubes (SWNTs) has been demonstrated via gel permeation chromatography (GPC). The UV-Vis spectrum of each fraction indicates an apparent "solubilization", as evident by the direct observation of all predicted optically allowed interband transitions between the mirror image spikes in the density of states of both metallic and semiconducting SWNTs with various tube diameters. As evident by the presence or absence of the 270 nm, pi-plasmon absorption, this "solubilization" is a dynamic process and leads to re-aggregation if left undisturbed for a couple of weeks or upon dissociation of the pendant octadecylamine groups. This non-destructive and highly versatile separation methodology opens up an array of possible applications for shortened SWNTs in nanostructured devices.

In this letter, we show that for all the so-called path-symmetric states, the measurement of parity of photon number at the output of an optical interferometer achieves maximal phase sensitivity at the quantum Cramer-Rao bound. Such optimal phase sensitivity with parity is attained at a suitable bias phase, which can be determined a priori. Our scheme is applicable for local phase estimation.PACS numbers: 42.50. St, 42.50.Dv, 42.50.Ex, 42.50.Lc Interferometry is a vital component of various precision measurement, sensing, and imaging techniques. It works based on mapping the quantity of interest on to the unknown phase of a system and estimating the latter; for example, the relative phase between the two modes or "arms" of an optical interferometer. Optical interferometry, often described in the Mach-Zehnder configuration, in general differs in the strategies of state preparation and detection. The conventional choice is to use a coherent light source and intensity difference detection. Assuming the unitary phase acquisition operator to be:(wheren a ,n b are the number operators associated with the modes,) the phase sensitivity of the conventional Mach-Zehnder interferometer (MZI) is bounded by the shot noise limit (SNL) δφ = 1/ √n (forn photons in the coherent state on average); whereas, protocols of quantum interferometry promise enhanced phase sensitivities by prescribing the use of states with nonclassical photon correlations and detection strategies that probe the particle nature of the output light, for example, via number counting [1]. As for such nonclassical states, the proposal to squeeze the vacuum state entering the unused port of the conventional MZI, by Caves in 1981, resulted in the first instance of a quantum-enhanced MZI capable of operating below the SNL [2]. Others, such as the twin-Fock state [3], the maximally path-entangled N00N state (|N, 0 + |0, N )/ √ 2, which reach the Heisenberg limit (HL) δφ = 1/N , were later proposed [4].Much of the latest experimental efforts in quantum interferometry have been focussed on attaining the HL [5]. The theory of quantum phase estimation aids in identifying potential schemes for such phase sensitivities [6]. It is based on the information-theoretical concept of the Cramer-Rao bound [7]. For the form of unitary phase acquisition considered in Eq. (1), the quantum CramerRao bound (QCRB)-an attribute of the quantum state input to the MZI alone (independent of detection)-at its best, can reach Heisenberg scaling in the absence of photon losses. On the other hand, the classical CramerRao bound (CCRB)-an attribute of the combination of a quantum state and detection strategy-can optimally reach the QCRB of the state. Uys and Meystre derived optimal quantum states, whose CCRB with number counting-based detection attains the HL in the absence of photon losses [8]. Lee et al. included photon losses to the problem and worked out the optimal inputs [9]. Meanwhile, Dorner et al. found optimal inputs in the presence of photon losses for the generic optimal detecti...