Simultaneous Measurement for Strain and Temperature Using Fiber Bragg Gratings and Multimode Fibers

An all-fiber sensor capable of simultaneous measurement of temperature and strain is newly presented. The sensing head is formed by a fiber Bragg grating combined with a section of multimode fiber that acts as a Mach-Zehnder interferometer for temperature and strain discrimination. The strain and temperature coefficients of multimode fibers vary with the core sizes and materials. This feature can be used to improve the strain and temperature resolution by suitably choosing the multimode fiber. For a 10 pm wavelength resolution, a resolution of 9.21 μ∈ in strain and 0.26°C in temperature can be achieved

Shifting Patterns in Marks and Registration: France, the United States and United Kingdom, 1870-1970

This paper looks at trademarks and brands, beyond the conventional interests of marketing and law, as a way to explaining the evolution of international business and economies in general. It shows that the perspective defended by many scholars such as Chandler (1990), Wilkins (1991, 1994) and Koehn’ (2001), about the Anglo-Saxon countries, and in particular the United States, leading the transition to modern trade-marks is narrow in its focus. Instead of the United States standing out as historically on the leading edge of innovation in the law and practice of trade marking, it appears from several directions to have been on the trailing edge. France and Britain have a more enduring interest in trademarking. The paper also looks at one particular subset of trade mark registration data – non durable consumer goods. These, and in particular food, are the dominant sectors in the three countries in terms of trademarking, reflecting the character of the sectors where imagery associated with the products is so central in competition. The paper relies on original data from three countries, France, the United Kingdom and the United States, in particular trade mark registrations, and the analysis spans for a period of one hundred years period 1870-1970.trade marks, brands, international business history, intellectual property rights, trademark law

Sexual dimorphism in bite performance drives morphological variation in chameleons

Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal's foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal's performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open-or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive body size and constraining performance

Core-Offset Small-Core-Diameter Dispersion Compensation Fiber Interferometer and its Applications in Fiber Sensors

We propose a core-offset small core diameter dispersion compensation fiber (DCF) interferometer and investigate its applications in fiber sensors. If the transverse force is applied to a short section of the DCF, there is almost no crosstalk on the transmission spectrum between the extinction ratio variation induced by the transverse force and the wavelength shift caused by the longitudinal strain or ambient temperature, which can be applied to measure both transverse and longitudinal strain, or both transverse strain and temperature, simultaneously. The proposed sensors have the advantages of low cost, simple and compact structure, and good reproducibility

Temperature- and Phase-Independent Lateral Force Sensor based on a Core-Offset Multi-Mode Fiber Interferometer

A novel lateral force sensor based on a core-offset multi-mode fiber (MMF) interferometer is reported. High extinction ratio can be obtained by misaligning a fused cross section between the single-mode fiber (SMF) and MMF. With the variation of the lateral force applied to a short section of the MMF, the extinction ratio changes while the interference phase remains almost constant. The change of the extinction ratio is independent of temperature variations. The proposed force sensor has the advantages of temperature- and phase-independency, high extinction ratio sensitivity, good repeatability, low cost, and simple structure. Moreover, the core-offset MMF interferometer is expected to have applications in fiber filters and tunable phase-independent attenuators

A new red giant-based distance modulus of 13.3 Mpc to the Antennae galaxies and its consequences

The Antennae galaxies are the closest example of an ongoing major galaxy merger, and thereby represent a unique laboratory for furthering the understanding of the formation of exotic objects (e.g., tidal dwarf galaxies, ultra-luminous X-ray sources, super-stellar clusters, etc). In a previous paper HST/WFPC2 observations were used to demonstrate that the Antennae system might be at a distance considerably less than that conventionally assumed in the literature. Here we report new, much deeper HST/ACS imaging that resolves the composite stellar populations, and most importantly, reveals a well-defined red giant branch. The tip of this red giant branch (TRGB) is unambiguously detected at Io(TRGB)=26.65 +/- 0.09 mag. Adopting the most recent calibration of the luminosity of the TRGB then yields a distance modulus for the Antennae of (m-M)o= 30.62 +/- 0.17 corresponding to a distance of 13.3 +/- 1.0 Mpc. This is consistent with our earlier result, once the different calibrations for the standard candle are considered. We briefly discuss the implications of this now well determined shorter distance.Comment: 11 pages, 3 figures, accepted for publication in the Ap