We demonstrated GaN-based photonic crystal (PC) nanobeam cavities by using the e-beam lithography and the suspended nanobeams were realized by focused-ion beam (FIB) milling. One resonant mode was clearly observed at 411.7 nm at 77K by optical pumping. The quality factor was measured to be to 7.4 × 10(2). Moreover, the degree of polarization value was measured to be 40%. The temperature-depende...

Photonic crystal nanobeam cavities are versatile platforms of interest for optical communications, optomechanics, optofluidics, cavity QED, etc. In a previous work [Appl. Phys. Lett. 96, 203102 (2010)], we proposed a deterministic method to achieve ultrahigh Q cavities. This follow-up work provides systematic analysis and verifications of the deterministic design recipe and further extends the ...

BACKGROUND The aim of the present study was to evaluate the cyclic fatigue resistance of Mtwo NiTi rotary instruments after clinical use by 1 experienced and 1 novice operator. MATERIAL/METHODS Cyclic fatigue testing of instruments was performed on tapered artificial canals with a 5 mm radius of curvature and 60° angle of curvature. Twenty Mtwo instruments for each size were selected and divid...

Nickel-titanium (NiTi) instruments are commonly used for shaping the root canal system in endodontic practice. They are more flexible and have better cutting efficiency than conventional stainless steel files. The superelasticity of NiTi rotary files allows the clinicians to produce the desirable tapered root canal form with a reduced tendency to canal transportation and instrument fracture. Hy...

In this study, flapwise bending vibration analysis of a tapered Timoshenko beam mounted on the periphery of a rotating rigid hub is performed. The governing differential equations of motion for pure bending are derived using the Hamilton’s principle and solved using the Differential Transform Method, DTM. During the derivation of the equations, effects of rotary inertia, shear deformation and h...

OBJECTIVE This study compared the sealing ability of 3 current filling techniques in root canals shaped with 2 different rotary systems. STUDY DESIGN Eighty human extracted mandibular premolars were divided randomly into 2 similar groups of 40 each and instrumented with either ProTaper (Dentsply Maillefer, Tulsa, OK; group A) or Mtwo (VDW; Antaeos, Munich, Germany; group B) rotary systems. Ea...

BACKGROUND Controlled, uniformly tapered radicular preparation is a great challenge in endodontics. Improper preparation can lead to procedural errors like transportation of foramen, uneven dentine thickness, stripping of root canal, formation of ledge, zip, and elbow in curved canals. These procedural errors and their sequel can adversely affect the prognosis of treatment. AIM/OBJECTIVES The...

Schematic illustration of a 1D diamond nanobeam cavity.