scholarly journals Polarimetric Sensitivity to Torsion in Spun Highly Birefringent Fibers

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1639 ◽  
Author(s):  
Dominik Kowal ◽  
Gabriela Statkiewicz-Barabach ◽  
Marta Bernas ◽  
Maciej Napiorkowski ◽  
Mariusz Makara ◽  
...  
Keyword(s):  
Linear Response ◽  
Experimental Studies ◽  
Spectral Interference ◽  
Microstructured Fibers ◽  
Side Hole ◽  
Interference Fringes ◽  
Fringe Width ◽  
Twist Rate ◽  
Response To Temperature ◽  
Spun Fibers

We report on experimental studies of polarimetric sensitivity to torsion in spun highly birefringent fibers. Two classes of spun fibers were examined, namely spun side-hole fibers and birefringent microstructured fibers with different birefringence dispersion, spin pitches, and spin directions. The polarimetric sensitivity to torsion was determined by monitoring a displacement of the spectral interference fringes arising in the output signal because of interference of polarization modes and induced by an additional fiber twist. Both the experimental results and the analytical predictions showed that the sensitivity to torsion normalized to the fringe width in the spun highly birefringent fibers increased asymptotically with the twist rate to the value of 1/ π rad−1. We have also studied the polarimetric response to temperature in the spun side-hole fibers. We have found that, in contrast to the torsional sensitivity, the temperature sensitivity decays asymptotically to zero with increasing fiber twist rate. Therefore, the spun fibers with short spin pitches are especially well suited for torsion measurements because the torsional sensitivity and the range of linear response are both enhanced in such fibers, while at the same time, the cross-sensitivity to temperature is reduced.

scholarly journals Effect of Temperature on Sporulation of Botryosphaeria dothidea, B. obtusa, and B. rhodina

Plant Disease ◽  
2004 ◽  
Vol 88 (3) ◽  
pp. 292-296 ◽  
Author(s):  
W. E. Copes ◽  
F. F. Hendrix
Keyword(s):  
Linear Response ◽  
Significant Interaction ◽  
Spore Production ◽  
Effect Of Temperature ◽  
Botryosphaeria Dothidea ◽  
Conidial Viability ◽  
Response To Temperature ◽  
Over Time ◽  
Spore Maturation

Three Botryosphaeria spp. were grown on autoclaved apple and peach stems in cotton-plugged tubes with constant moisture at 6, 12, 18, 24, and 30°C to determine the effect of temperature on sporulation. Number of conidia per pycnidium was determined weekly from 4 to 10 weeks after inoculation. The experiment was repeated three times. Maximum sporulation occurred at 24°C with B. dothidea and at 18 and 24°C with B. obtusa. Spore production of both fungi showed a quadratic curvilinear response to temperature. Pycnidia were erumpent, typical of their habit in nature. Maximum sporulation of B. rhodina occurred at 12, 24, and 30°C instead of at a distinctive peak. Of the three fungi, B. rhodina produced the greatest number of conidia per pycnidium at all temperatures. Mycelia and pycnidia of B. rhodina grew on top of the bark, which is atypical of their habit in nature. For spore production by B. dothidea, there was a significant interaction between temperature and time. Maximum sporulation over the 10-week period occurred in week 4 and/or 6 for B. dothidea at 12, 18, and 24°C, with a linear response at 12 and 24°C (P ≤0.05). Conidial maturation of B. obtusa and B. rhodina had a quadratic curvilinear response due to temperature, with a maximum maturation at 12, 18, and 24°C with B. obtusa and at 24°C with B. rhodina. Spore maturation would affect longevity of conidial viability. Maximum spore production over time and percent pigmented spores over time by B. obtusa, and spore maturation over time by B. rhodina occurred in weeks 8, 9, and 10 with a significant linear response (P ≤ 0.05). All three Botryosphaeria spp. produced conidia over the 6 to 30°C range and over the 7-week period (weeks 4 to 10), with maximum sporulation or spore maturation at 18 to 24°C.

RESULTS OF STUDIES ON DEPENDENCE BETWEEN THE FUNCTIONING OF GAS OPERATED GUN MECHANISMS AND DIAMETER OF ADJUSTING HOLE

2018 ◽  
Vol 145 (1) ◽  
pp. 105-116
Author(s):  
Jacek Kijewski ◽  
Grzegorz Leśnik
Keyword(s):  
Experimental Studies ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Side Hole ◽  
Satisfactory Level ◽  
Theoretical Investigations ◽  
Set Up ◽  
The Cost

Results of theoretical and experimental studies on the influence of diameter of an adjusting (outflow) hole on the operation of mechanisms of automatic weapons operating on a principle of barrel side hole returning gases are presented in the paper. Experimental investigations were performed on a modified laboratory set-up for testing the functioning of mechanisms of a gas operated rifle. These results were compared with results of simulating studies. Theoretical investigations may limit the scope of experimental tests and save the cost and time of designing the firearms as a satisfactory level of compliance for the results was achieved.

An Improved Data Processing Method in Differential White Light Spectral Interferometry for the Measurement of Thickness of Ultra-Thin Metallic Foil

2007 ◽  
Vol 364-366 ◽  
pp. 560-565
Author(s):  
Yan Li Du ◽  
Hui Min Yan ◽  
Xiu Da Zhang
Keyword(s):  
White Light ◽  
Thickness Measurement ◽  
Spectral Interference ◽  
Measuring System ◽  
Source Spectrum ◽  
Interferometric Method ◽  
Metallic Foil ◽  
Interference Fringes ◽  
Data Processing Method ◽  
Measurement Of Thickness

The accurate thickness measurement of Ultra-thin rolling metallic foil has an important role in industrial or some special applications. Unfortunately, commercial thickness meters do not provide high precision measurements non-destructively. A new spectral-domain interferometric method for measuring absolute thickness of Ultra-thin metallic foil is proposed here. The thickness is measured by differential white light spectral interferometer. Two differential Michelson Interferometers (MI) are used as basic measuring system to obtain the spectral interference fringes on the spectrometers. The spectral interference between both beams, which shows up a periodic modulation of the source spectrum with the period dependent on the OPD, serves as an illustration of a technique for measuring both OPDs and displacements in a range dependent on the source spectrum width. Therefore, the interference fringes only depend on the OPD due to the thickness of metallic foil and are unrelated to the position of the foils in the system, which is insensitive to the vibration. The spectral interference fringes are resolved over a wide spectral range and the absolute thickness of metallic foil can be calculated by measuring the OPD with a modified extremum method based on the least root mean square (RMS) deviation. The theoretical analysis and preliminary experiments indicate that the technique can measure the thickness of foils in the range of 1μm to 80μm, and it requires less than 50ms within the single measurement. Experimental results are presented.

scholarly journals Temperature Sensor Based on an Asymmetric Two-Hole Fiber Using a Sagnac Interferometer

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
René Domínguez-Cruz ◽  
Daniel A. May-Arrioja ◽  
Rodolfo Martínez-Manuel ◽  
Daniel Lopez-Cortes
Keyword(s):  
Temperature Difference ◽  
Temperature Sensor ◽  
Linear Response ◽  
Silica Fiber ◽  
Wavelength Shift ◽  
Sagnac Interferometer ◽  
Microstructured Fiber ◽  
Microstructured Fibers ◽  
Transverse Geometry ◽  
Transmitted Spectrum

We report in this paper a temperature sensor based on an asymmetric two-hole fiber (ATHF) using a Sagnac interferometer (SI) configuration. The operation principle is based on the birefringence change induced by the temperature difference between the air holes and the silica fiber. As a result, the transmitted spectrum of the SI exhibits a sinusoidal profile which is shifted when the temperature is increased. A linear wavelength shift as a function of temperature is observed, and a sensitivity of 2.22 nm/°C was achieved using a 2 m long asymmetric THF, which is in the same order as those previously reported using similar microstructured fibers. The advantage of this system is a linear response, the use of a microstructured fiber with a simpler transverse geometry, and the use of bigger holes which can facilitate the insertion of several materials and improve the sensitivity of the sensor for different applications.

Photographic Equidensitometry of High Voltage Electron Images of Thick Noncrystalline Materials

1972 ◽  
Vol 30 ◽  
pp. 594-595
Author(s):  
Keinosuke Kobayashi
Keyword(s):  
High Voltage ◽  
Linear Response ◽  
Thickness Distribution ◽  
Contour Map ◽  
Mass Thickness ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Homogeneous Particle ◽  
Photographic Emulsions ◽  
Logarithmic Relation

Equidensitometry as developed by E. Lau and W. Krug has been little used in the analysis of ordinary electron photomicrographs, yet its application to the high voltage electron images proves merits of this procedure. Proper sets (families) of equidensities as shown in the next page are able to reveal the contour map of mass thickness distribution in thick noncrystalline specimens. The change in density of the electron micrograph is directly related to the mass thickness of corresponding area in the specimen, because of the linear response of photographic emulsions to electrons and the logarithmic relation between electron opacity and mass thickness of amorphous object.This linearity is verified by equidensitometry of a spherical solid object as shown in Fig. 1a. The object is a large (1 μ) homogeneous particle of polystyrene. Fig. 1b is a composite print of three equidensities of the 1st order prepared from Fig. 1a.

Quanitative aspects of electron diffraction using electron holography

1995 ◽  
Vol 53 ◽  
pp. 616-617
Author(s):  
E. Völkl ◽  
L.F. Allard ◽  
B. Frost ◽  
T.A. Nolan
Keyword(s):  
Electron Beam ◽  
Electron Diffraction ◽  
Software Package ◽  
Spatial Coherence ◽  
Electron Holography ◽  
Image Intensity ◽  
Interference Fringes ◽  
Complex Image ◽  
The Difference ◽  
Recorded Image

Off-axis electron holography has the well known ability to preserve the complex image wave within the final, recorded image. This final image described by I(x,y) = I(r) contains contributions from the image intensity of the elastically scattered electrons IeI (r) = |A(r) exp (iΦ(r)) |, the contributions from the inelastically scattered electrons IineI (r), and the complex image wave Ψ = A(r) exp(iΦ(r)) as:(1) I(r) = IeI (r) + Iinel (r) + μ A(r) cos(2π Δk r + Φ(r))where the constant μ describes the contrast of the interference fringes which are related to the spatial coherence of the electron beam, and Φk is the resulting vector of the difference of the wavefront vectors of the two overlaping beams. Using a software package like HoloWorks, the complex image wave Ψ can be extracted.

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