An electrosurgical device for directing energy to a target volume of tissue includes a coaxial feedline having an inner conductor, an outer conductor coaxially disposed around the inner conductor, and a dielectric material disposed therebetween. The medium, the lightguide and a surrounding medium have refractive indices selected such that light entering the lightguide is internally reflected within the lightguide to provide substantially uniform illumination of the conduits. Further, the servo system abandons erases the learned value in a memory when an impact applied to the disk drive and exceeding a tolerance value is detected during the learning operation. Moreover, such amine that is a bivalent group and that is represented by -Ar-N\u2550N-Ar\u2032-, where Ar and Ar\u2032 are independently aromatic hydrocarbon bivalent groups, is intercalated in a layered crystal of a polymer such as polymuconic acid, the layered crystal including a carboxyl group. The brake maintaining arrangement is configured and arranged to hold the bicycle braking device in the brake applying position in response to movement of the rider operating arrangement to the predetermined braking position such that the braking force of the bicycle braking device is continually and consistently applied.