Search results for " cavi"
showing 10 items of 537 documents
Numerical 2D And 3D Simulations of a Spherical Fabry–Pérot Resonator for Application as a Reference Cavity for Laser Frequency Stabilisation
2015
Abstract We report on the results of a numerical study of deformations of a spherical Fabry-Pérot cavity that can be used for laser frequency stabilisation. It is demonstrated that for a precise simulation of the cavity deformations a 3D model has to be used instead of a simpler 2D model, which employs simulation on the symmetry plane of the cavity. To lower the sensitivity to environmental perturbations, it is suggested to use a material with a low density and a high Young’s modulus. We also show that the mechanical resonance frequencies of the cavity are mainly determined by the size of the cavity.
Actively mode-locked fiber laser with an acousto-optic in-fiber superlattice modulator
2009
All-fiber lasers permit the development of efficient, robust and compact coherent light sources. However, all-fiber active mode-locking is a challenging objective and very few all-fiber techniques have been published [1–3]. The development of a low-insertion-loss acoustically-induced superlattice modulator that works in the MHz range has demonstrated its suitability to perform active mode-locking of an all-fiber laser. While travelling extensional acoustic waves launched along a fiber Bragg grating (FBG) produce stationary side bands and a frequency shift [4,5], we found that the excitation of a standing extensional acoustic wave should produce no frequency shift, but the amplitude modulati…
Roentgenographic in vitro investigation of frequency and location of curvatures in human maxillary premolars.
2006
The aim of this study was to determine the location of the root canal curvature and measure the distance from the CEJ to the first curvature using in vitro methods. Extracted maxillary premolars (n = 358) were fixed and digitally radiographed using the parallel technique. Excluded from further analysis were teeth with root caries, artificial crowns, extensive fillings, or endodontic treatments. The results were descriptively analyzed and the cumulative frequencies were calculated. The median values of the distance between CEJ and first curvature were for the first right premolars 8.4 mm (buccal) and 8.5 mm (palatal), for the first left premolars 9.1 mm (buccal) and 8.9 mm (palatal). The med…
An inductively heated hot cavity catcher laser ion source.
2015
An inductively heated hot cavity catcher has been constructed for the production of low-energy ion beams of exotic, neutron-deficient Ag isotopes. A proof-of-principle experiment has been realized by implanting primary (107)Ag(21+) ions from a heavy-ion cyclotron into a graphite catcher. A variable-thickness nickel foil was used to degrade the energy of the primary beam in order to mimic the implantation depth expected from the heavy-ion fusion-evaporation recoils of N = Z (94)Ag. Following implantation, the silver atoms diffused out of the graphite and effused into the catcher cavity and transfer tube, where they were resonantly laser ionized using a three-step excitation and ionization sc…
A case of unusual anatomy: a maxillary lateral incisor with three canals.
1999
Case report A case of an unusual maxillary lateral incisor with three root canals is presented. The patient presented with localized swelling and a sinus tract. Because of its abnormal anatomical configuration, the tooth presented diagnostic and procedural difficulties. Conventional root canal treatment was performed successfully.
Nachweis von Markembolien wÄhrend Oberschenkelmarknagelungen mittels transösophagealer Echokardiographie
1989
Kardiopulmonale Komplikationen nach Marknagelosteosynthesen, insbesondere am Oberschenkel, sind bekannt. WAhrend der Nagelung einer Oberschenkelquerfraktur mit einem, geschlossenen distalen Fragment konnten durch transsophageale Echokardiographie im rechten Herzen durchstromende echogene Partikel nachgewiesen werden. Das intrakardiale Auftreten dieser Partikel stand in engem zeitlichen Zusammenhang mit dem Aufbohren der femoralen Markhohle und kann als Nachweis verschleppter Marksubstanz gedeutet werden. Die intraoperative Echokardiographie bietet sich an, Untersuchungen uber die Pathophysiologie kardiopulmonaler VerAnderungen nach Marknagel osteosynthesen durchzufuhren und die EffektivitAt…
Microwave response of a cylindrical cavity made of bulk MgB2 superconductor
2007
Automated segmentation and description of the internal morphology of human permanent teeth by means of micro-CT
2020
High-resolution micro-computed tomography is a powerful tool to analyze and visualize the internal morphology of human permanent teeth. It is increasingly used for investigation of epidemiological questions to provide the dentist with the necessary information required for successful endodontic treatment. The aim of the present paper was to propose an image processing method to automate parts of the work needed to fully describe the internal morphology of human permanent teeth. One hundred and four human teeth were scanned on a high-resolution micro-CT scanner using an automatic specimen changer. Python code in a Jupyter notebook was used to verify and process the scans, prepare the dataset…
Antibakterielle Konzentrationen in Serum und Geweben aus dem Zahn-Kieferbereich nach perioperativer Einnahme von Propicillin
1983
Nach der operativen Entfernung radikularer und follikularer Zysten im Kieferbereich wurden bei 40 Patienten Serum, Knochen, Zystenbalg und Zystenflussigkeit auf ihren Gehalt an Propicillin untersucht. Die Patienten hatten ein oder zwei Stunden vor der Entnahme der Untersuchungsmaterialien 1 Mega E (0,7 g) Propicillin als Oblongtablette oral erhalten. Ein bzw. zwei Stunden nach der Einnahme des Propicillin betrugen die Verteilungskoeffizienten zwischen Serum und den drei Geweben 0,78 bzw. 0,87 fur die Spongiosa, 0,07 bzw. 0,06 fur den Zystenbalg und 0,14 bzw. 0,08 fur die Zystenflussigkeit. Die mittleren Konzentrationen in allen drei Geweben lagen mindestens zwei Stunden lang deutlich uber d…