We study the quenched random disorder (QRD) effects created by aerosil dispersion in the octylcyanobiphenyl (8CB) liquid crystal (LC) using atomic force microscopy technique. Gelation process in the 8CB+aerosil gels yields a QRD network which also changes the surface topography. By increasing the aerosil concentration, the original smooth pattern of LC sample surfaces is suppressed by the emergence of a fractal aerosil surface effect and these surfaces become more porous, rougher and they have more and larger crevices. The dispersed aerosil also serves as pinning centers for the liquid crystal molecules. It is observed that via the diffusion-limitedaggregation process, aerosil nano-particles yield a fractal-like surface pattern for the less disordered samples. As the aerosil dispersion increases, the surface can be described by more aggregated regions, which also introduces more roughness. Using this fact, we show that there is a net correlation between the short-range ordered x-ray peak widths (the results of previous x-ray diffraction experiments) and the calculated surface roughness. In other words, we show that these QRD gels can also be characterized by their surface roughness values.

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Low temperature powder inelastic neutron scattering measurements were performed on three different powder samples; parent BaMn2As2,12.5% K-doped Ba0.875K0.125Mn2As2 and 25% K-doped Ba(0.75)K0.25Mn2As2. The Heisenberg Model involving J1-J2-Jz coupling constants were compared to the data by a powder integration routine using Monte Carlo integration methods. The best magnetic parameters were selected using a chi-square test where model intensities were compared to the full (q,E) dependence of magnetic scattering. A key step to this analysis is the characterization of the background which is formed mostly by phonon scattering intensities along with other sources including the magnetic impurity scattering events. The calculated powder magnetic intensities added to the estimated background obtained from the non-magnetic high momentum transfer region. The agreement between the simulated and the raw data enabled us to perform quantitative analysis of the unreacted MnO impurities. Overall, this is another confirmation along with earlier studies using this technique, that magnetic exchange constants can be calculated within an acceptable range with a very quick inelastic neutron powder experiment without need for a single crystal sample.

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After Sultan Abdulhamid II settled in Yildiz Palace in 1878 and started the construction of his residence buildings, he preferred the cheapest and fastest building technology: Timber framed construction. Timber framed construction technique was predominantly used in the neighborhoods nearby the Palace inhabited by the members of imperial family or high bureaucracy in the last quarter of the 19 th century. Ottoman archival records reveal the construction of many timber framed post disaster houses constructed in the precincts of damaged masonry palaces and mansions after the 1894 Istanbul earthquake. One of those postearthquake timber framed buildings is Kemaleddin Efendi's house constructed in the courtyard of Dolmabahce Palace. Starting with the examples in Yildiz Palace, the timber framed building systems of the late 19 th century differ from the traditional timber framed constructions: The factory / workshop shaped timber posts, beams and ornaments and the industrial products of the 19 th century such as cement and galvanized wire used for plastering the timber walls or corrugated galvanized sheets used as roof covering brought the standardization and rationalization of traditional timber constructions. However, the industrial products of the 19 th century are often considered as inappropriate interventions and are replaced with traditional materials during the conservations. This study discusses the conservation method of Kemaleddin Efendi timber framed house, based on chemical/ physical analyses of industrial building materials and the cost estimates prepared by building contractor Serkiz Balyan in 1894.