1,940 research outputs found
The Chemical Composition of Cattle Hair. I, The Fat, Ash and Nitrogen Content
Author Institution: Ohio Agricultural Experiment Station, Wooste
Optical Frequency Comb Generation based on Erbium Fiber Lasers
Citation: Droste, S., Ycas, G., Washburn, B. R., Coddington, I., & Newbury, N. R. (2016). Optical Frequency Comb Generation based on Erbium Fiber Lasers. Nanophotonics, 5(2), 196-213. doi:10.1515/nanoph-2016-0019Optical frequency combs have revolutionized optical frequency metrology and are being actively investigated in a number of applications outside of pure optical frequency metrology. For reasons of cost, robustness, performance, and flexibility, the erbium fiber laser frequency comb has emerged as the most commonly used frequency comb system and many different designs of erbium fiber frequency combs have been demonstrated. We review the different approaches taken in the design of erbium fiber frequency combs, including the major building blocks of the underlying mode-locked laser, amplifier, supercontinuum generation and actuators for stabilization of the frequency comb
Theory of radiation trapping by the accelerating solitons in optical fibers
We present a theory describing trapping of the normally dispersive radiation
by the Raman solitons in optical fibers. Frequency of the radiation component
is continuously blue shifting, while the soliton is red shifting. Underlying
physics of the trapping effect is in the existence of the inertial gravity-like
force acting on light in the accelerating frame of reference. We present
analytical calculations of the rate of the opposing frequency shifts of the
soliton and trapped radiation and find it to be greater than the rate of the
red shift of the bare Raman soliton. Our findings are essential for
understanding of the continuous shift of the high frequency edge of the
supercontinuum spectra generated in photonic crystal fibers towards higher
frequencies.Comment: Several misprints in text and formulas corrected. 10 pages, 9
figures, submitted to Phys. Rev.
Pre–post intervention exploring cognitive function and relationships with weight loss, intervention adherence and dropout
Objective: To evaluate the association between baseline cognitive function, intervention dropout, adherence and 3-month weight loss (WL) when controlling for confounding demographic variables.
Methods: 107 (Mage = 40.9 yrs.), BMI in the overweight and obese range (BMI = 35.6 kg/m2), men (N = 17) and women (N = 90) completed a 3-month WL intervention. Participants attended weekly behavioral sessions, comply with a reduced calorie diet, and complete 100 min of physical activity (PA)/wk. Cognitive function tasks at baseline included Flanker (attention), Stroop (executive control) and working memory, demographics, body weight and cardiovascular fitness were assessed at baseline. Session attendance, adherence to PA and diet were recorded weekly.
Results: Baseline attention was positively correlated with age (p \u3c .05), education (p \u3c .05), attendance (p \u3c .05), diet (p \u3c .05) and PA (p \u3c .05). Baseline executive control (p \u3c .05) and working memory (p \u3c .05) were each associated with % WL. Baseline executive control (p \u3c .01) and working memory (p \u3c .001) were also each associated with education. ANOVA indicated that baseline attention (p \u3c .01) was associated with WL, specifically for comparing those who achieved 5–10% WL (p \u3c .01) and those who achieved greater than 10% WL (p \u3c .01) to those who dropped.
Significance: Results suggest that stronger baseline attention is associated with completion of a 3-mo. WL intervention. Executive control and working memory are associated with amount of WL achieved.
NCT registration: US NIH Clinical Trials, NCT0166471
In Situ Resistance Measurements of Strained Carbon Nanotubes
We investigate the response of multi-walled carbon nanotubes to mechanical
strain applied with an Atomic Force Microscope (AFM) probe. We find that in
some samples, changes in the contact resistance dominate the measured
resistance change. In others, strain large enough to fracture the tube can be
applied without a significant change in the contact resistance. In this case we
observe that enough force is applied to break the tube without any change in
resistance until the tube fails. We have also manipulated the ends of the
broken tube back in contact with each other, re-establishing a finite
resistance. We observe that in this broken configuration the resistance of the
sample is tunable to values 15-350 kW greater than prior to breaking.Comment: Submitted to Applied Physics Letter
Studies of h/e Aharonov-Bohm Photovoltaic Oscillations in Mesoscopic Au Rings
We have investigated a mesoscopic photovoltaic (PV) effect in micron-size Au
rings in which a dc voltage Vdc is generated in response to microwave
radiation. The effect is due to the lack of inversion symmetry in a disordered
system. Aharonov-Bohm PV oscillations with flux period h/e have been observed
at low microwave intensities for temperatures ranging from 1.4 to 13 K. For
moderate microwave intensities the h/e PV oscillations are completely quenched
providing evidence that the microwaves act to randomize the phase of the
electrons. Studies of the temperature dependence of Vdc also provide evidence
of the dephasing nature of the microwave field. A complete theoretical
explanation of the observed behavior seems to require a theory for the PV
effect in a ring geometry.Comment: 10 pages (RevTex twocolumn style), 8 figures-2 pages (one postscript
file) To be published in Phys. Rev.
Aeronautic Instruments. Section V : Power Plant Instruments
Part 1 gives a general discussion of the uses, principles, construction, and operation of airplane tachometers. Detailed description of all available instruments, both foreign and domestic, are given. Part 2 describes methods of tests and effect of various conditions encountered in airplane flight such as change of temperature, vibration, tilting, and reduced air pressure. Part 3 describes the principal types of distance reading thermometers for aircraft engines, including an explanation of the physical principles involved in the functioning of the instruments and proper filling of the bulbs. Performance requirements and testing methods are given and a discussion of the source of error and results of tests. Part 4 gives methods of tests and calibration, also requirements of gauges of this type for the pressure measurement of the air pressure in gasoline tanks and the engine oil pressure on airplanes. Part 5 describes two types of gasoline gauges, the float type and the pressure type. Methods of testing and calibrating gasoline depth gauges are given. The Schroeder, R. A. E., and the Mark II flowmeters are described
Macroscopic Quantum Tunneling of a Fluxon in a Long Josephson Junction
Macroscopic quantum tunneling (MQT) for a single fluxon moving along a long
Josephson junction is studied theoretically. To introduce a fluxon-pinning
force, we consider inhomogeneities made by modifying thickness of an insulating
layer locally. Two different situations are studied: one is the quantum
tunneling from a metastable state caused by a single inhomogeneity, and the
other is the quantum tunneling in a two-state system made by two
inhomogeneities. In the quantum tunneling from a metastable state, the decay
rate is estimated within the WKB approximation. Dissipation effects on a fluxon
dynamics are taken into account by the Caldeira-Leggett theory. We propose a
device to observe quantum tunneling of a fluxon experimentally. Required
experimental resolutions to observe MQT of a fluxon seem attainable within the
presently available micro-fabrication technique. For the two-state system, we
study quantum resonance between two stable states, i.e., macroscopic quantum
coherence (MQC). From the estimate for dissipation coefficients due to
quasiparticle tunneling, the observation of MQC appears to be possible within
the Caldeira-Leggett theory.Comment: 30 pages LaTeX including 11 PS figures, using jpsj.sty. To be
published on J. Phys. Soc. Jpn. Overestimates for damping amplitude is
correcte
A cross validation of Consumer-Based Brand Equity (CBBE) with Private Labels in Spain
Molinillo,S., Ekinci, Y., Japutra, A. (2014)'A cross validation of Consumer-Based Brand Equity (CBBE) with Private Labels in Spain'. in MartÃnez-López, Gázquez-Abad, J.C. and Sethuraman, R. J.A. (eds.) Advances in National Brand and Private Label Marketing. Second International Conference, 2015. Springer Proceedings in Business and Economics, pp. 113-125In recent years a number of Consumer-Based Brand Equity (CBBE) models and measurement scales have been introduced in the branding literature. However, examinations of brand equity in Private Labels (PL) are rather limited. This study aims to compare the validity of the two prominent CBBE models those introduced by Yoo and Donthu (2001) and Nam et al. (2011). In order to test the models and make this comparison, the study collected data from 236 respondents who rated private labels in Spain. A list of 30 different fashion and sportswear PL was introduced to respondents. These brands do not make any reference to the retail store in which they are sold. Research findings suggest that the extended CBBE model introduced by Nam et al. (2011) and Ciftci et al. (2014) is more reliable and valid than Yoo and Donthu’s model for assessing PL. Theoretical contributions and managerial implications are discussed.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
Geometry dependent dephasing in small metallic wires
Temperature dependent weak localization is measured in metallic nanowires in
a previously unexplored size regime down to width nm. The dephasing time,
, shows a low temperature dependence close to quasi-1D
theoretical expectations () in the narrowest wires,
but exhibits a relative saturation as for wide samples of the same
material, as observed previously. As only sample geometry is varied to exhibit
both suppression and divergence of , this finding provides a new
constraint on models of dephasing phenomena.Comment: 6 pages, 3 figure
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