Autor: Bock, W.J. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Unique anatomy of lagomorph calcaneus
Autorzy:: Bleefeld, A R
Bock, W.J.
Tematy:: Lagomorpha
lagomorph calcaneus
mammal
calcaneus
anatomy; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/21813.pdf Link otwiera się w nowym oknie
Opis:: The mammalian order Lagomorpha (hares, rabbits, pikas) comprises two families (Ochotonidae and Leporidae; McKenna and Bell 1998; Nowak 1999), and Recent members have a nearly world−wide distribution (Hoffman 1993; Nowak 1999). Detailed examination of the pedal morphology of extant and fossil lagomorphs revealed a unique channel (the “calcaneal canal”) running diagonally through the lagomorph calcaneus. The ancientness, ubiquity, and appearance of the calcaneal canal in all, including the earliest recognized lagomorph calcanea, and its absence from the pedes of other mammalian taxa, may indicate a long evolutionary separation of lagomorphs from other, previously suggested lagomorph relatives.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Temperature Cross-Sensitivity for Highly Refractive Index Sensitive Nanocoated Long-Period Gratings
Autorzy:: Grochowski, J.
Myśliwiec, M.
Mikulic, P.
Bock, W.
Śmietana, M.
Tematy:: 42.70.Ce
42.79.Gn
07.07.Df
81.20.Fw; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1399344.pdf Link otwiera się w nowym oknie
Opis:: There is a demand for highly refractive index sensitive devices simultaneously insensitive to temperature (T) changes. We investigate both T and refractive index sensitivity of long-period gratings coated with 100 nm thin high refractive index (n ≈ 1.9 at λ = 1550 nm) silicon nitride $(SiN_{x})$ film. The long-period gratings with period of 500 μm were induced in standard Corning SMF28 fibre using electric arc and nanocoated with $SiN_{x}$ by radio frequency plasma enhanced chemical vapour deposition method. As a sensorial effect we investigated resonance shift with temperature variations (from 30 to 70°C) for measurement in deionized water ($n_{D}$ = 1.33) and glycerine ($n_{D}$ = 1.46). In case of measurements in water for resonance observed at λ = 1510 nm, refractive index sensitivity of - 85 nm/RIU and temperature sensitivity of 0.09 nm/C $(H_2O)$ were obtained which gives refractive index-T sensitivity ratio (RI/T) of - 944°C/RIU. Refractive index and T sensitivity of sensor covered with $SiN_{x}$ film increased to - 618 nm/RIU and 0.22 nm/°C, respectively. Thanks to nanocoating deposition, refractive index-T sensitivity ratio was improved by factor of 3. In case of measurements in glycerine significant influence of glycerine's thermo-optic coefficient on obtained results was observed. It is worth noticing that $SiN_{x}$ coating stabilizes sensing behaviour of the sensor.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Effect of Wet Etching of Arc-Induced Long-Period Gratings on Their Refractive Index Sensitivity
Autorzy:: Myśliwiec, M.
Grochowski, J.
Krogulski, K.
Mikulic, P.
Bock, W.
Śmietana, M.
Tematy:: 42.70.Ce
42.79.Gn
07.07.Df
81.20.Fw; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1399391.pdf Link otwiera się w nowym oknie
Opis:: The paper presents highly refractive index sensitive operation of long-period gratings enhanced by wet etching of the fiber cladding. Long-period gratings with period of 283 μm were induced in Corning SMF28 optical fibre using electric arc technique. Then etching in hydrofluoric (HF) acid solution has been applied to improve operation of the sensor. Sensitivity improvement effect induced by fiber cladding reduction has been numerically simulated. The developed numerical model enables quick estimation of cladding thickness reduction essential to achieve dispersion turning point. At this point long-period gratings reaches maximum sensitivity to external medium refractive index. Simulation showed that dispersion turning point for this long-period grating is achieved by cladding thickness reduction of 1.7 μm. We obtained good simulation match with experimental results, where approximately the same thickness was etched. The refractive index sensitivity of the long-period grating-based sensor has been improved by factor of 5. Since long-period grating period is limited when using electric arc fabrication method, this physical limitation makes difficult achievement of dispersion turning point and reaching maximum sensitivity of the long-period grating. We show that sensitivity of electric arc induced long-period grating can be significantly improved by post processing techniques such as wet etching.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 4.

Tytuł:: Redshifted Fe K$\alpha$ line from the unusual $\gamma$-ray source PMN J1603–4904
Autorzy:: Kreikenbohm, A.
Krauß, F.
Pottschmidt, K.
Müller, C.
Kadler, M.
Ojha, R.
Carpenter, B.
McConville, W.
Markowitz, A.
Wilms, J.
Stawarz, Łukasz
Böck, M.
Dutka, M.
Beuchert, T.
Dauser, T.
Taylor, G. B.
Opis:: Context. Multiwavelength observations have revealed the highly unusual properties of the $\gamma$-ray source PMN J1603-4904, which are difficult to reconcile with any other well-established $\gamma$-ray source class. The object is either a very atypical blazar or a compact jet source seen at a larger angle to the line of sight. Aims: To determine the physical origin of the high-energy emission processes in PMN J1603-4904, we study the X-ray spectrum in detail. Methods: We performed quasi-simultaneous X-ray observations with XMM-Newton and Suzaku in 2013 September. This resulted in the first high signal-to-noise X-ray spectrum of this source. Results: The 2-10 keV X-ray spectrum can be well described by an absorbed power law with an emission line at 5.44 $\pm$ 0.05 keV (observed frame). We interpret this feature as a K$\alpha$ line from neutral iron and accordingly determine the redshift of PMN J1603-4904 to be z = 0.18 $\pm$ 0.01, which corresponds to a luminosity distance of 872 $\pm$ 54 Mpc. Conclusions: The detection of a redshifted X-ray emission line further challenges the original BL Lac classification of PMN J1603-4904. This result suggests that the source is observed at a larger angle to the line of sight than expected for blazars, and thus the source would add to the elusive class of $\gamma$-ray loud misaligned-jet objects, possibly a $\gamma$-ray bright young radio galaxy.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego