Browsing by Subject "transmission"

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Open Access
Reflections of an external world in the Ottoman mind : the production and transmission of knowledge in the 18th Ottoman society
(2011) Tekgül, Nil
This thesis attempts to investigate Ottoman “perception of knowledge”. The construction of collective perception of knowledge, various knowledge concepts, spaces for knowledge production, modes and channels of transmission are analyzed. It discusses the role of oral and written modes of transmission and claims that the loosening classical organizational structure of the Empire and the social transformation experienced in the 18th century, had an impact on the society’s perception of knowledge. It is assumed in this thesis that knowledge was being transmitted by three different layers of society, namely “high-ranking professionals”, “secondary professionals” and the “public”. The main argument of this thesis is being tested by the empirical data showing the professional status of knowledge transmitters, the books they owned, and the contents of the books which were classified with respect to the kind of knowledge they possessed. The empirical data used consists of 2 registers of kısmet-i askeriye, individual distinct records chosen from Ba!bakanlık Osmanlı Ar!ivi Ba! Muhasebe Kalemi dating the first half of 18th century, and one Üsküdar court record. This thesis carries the previous research done on “Ottoman book culture” one step further for a better and meaningful interpretation of the results, and views the role of books from the perspective of perception of knowledge. Thus, it also hopes to provide an insight to the question of “Why did printing come late to Ottoman world?” that has occupied the minds of Ottoman historians for half a century.
Open Access
Surface plasmon based enhanced transmission of electromagnetic waves
(2004) Bıyıklı, Süheyla Sena Akarca
Grating-coupling phenomena between surface plasmons and electromagnetic waves are studied in the microwave spectrum using metallic gratings. Transmission and reflection measurements were carried out to observe the transmitted and reflected radiation around the surface plasmon resonance frequencies. Grating structures with subwavelength apertures were designed for transmission experiments. Measurements were done in the microwave spectrum of 10−37.5 GHz, corresponding to a wavelength region of 8−30 mm. The Al samples had a grating periodicity of 16 mm. A 2 mm-wide subwavelength slit was opened for transmission samples. Samples with one/double-sided gratings displayed remarkably enhanced transmission and directivity with respect to the reference sample without gratings. The experimental results agreed well with theoretical simulations. ~50% transmission at 20.7 mm, ~25-fold enhancement, and ±4° angular divergence was achieved with a ~λ/10 aperture. Reflection measurements of one-sided grating sample resulted in clear observation of surface plasmon coupling phenomena. Reflectivity peaks were measured around theoretically calculated resonance frequencies.