The 26 December 2004 earthquake and tsunami unfairly hit the different ethnic groups of Aceh, Indonesia. About 170,000 Acehnese and Minangkabau people died in the Northern tip of Sumatra while only 44 Simeulue people passed away in the neighbouring Simeulue island located near the earthquake epicentre. Such a difference in the death toll does not lie in the nature of the hazard but in different human behaviours and ethnic contexts. The present study draws on a contextual framework of analysis where people's behaviour in the face of natural hazards is deeply influenced by the cultural, social, economic and political context. Questionnaire-based surveys among affected communities, key informant interviews and literature reviews show that the people of Simeulue detected the tsunami very early and then escaped to the mountains. On the other hand, Acehnese and Minangkabau people, respectively in the cities of Banda Aceh and Meulaboh, did not anticipate the phenomenon and were thus caught by the waves. The different behaviours of the victims have been commanded by the existence or the absence of a disaster subculture among affected communities as well as by their capacity to protect themselves in facing the tsunami. People's behaviours and the capacity to protect oneself can be further tracked down to a deep tangle of intricate factors which include the armed conflict that has been affecting the province since the 1970s, the historical and cultural heritage and the national political economy system. This paper finally argues that the uneven impact of the 26 December 2004 earthquake and tsunami in Aceh lies in the different daily life conditions of the ethnic groups struck by the disaster.

The discovery of topological insulators (TIs) has motivated detailed studies on their physical properties, especially on their novel surface states via strong spin–orbit interactions. However, surface-state-related thermoelectric properties are rarely reported, likely because of the involvement of their bulk-dominating contribution. In this work, we report thermoelectric studies on a TI bismuth selenide (Bi2Se3) nanowire (NW) that exhibit a larger surface/volume ratio. Uniform single-crystalline TI Bi2Se3 NWs were successfully synthesized using a stress-induced growth method. To achieve the study of the thermoelectric properties of a nanowire (NW), including electrical conductivity (σ), Seebeck coefficient (S), and thermal conductivity (κ), a special platform for simultaneously performing all measurements on a single wire was designed. The properties of σ, S, and κ of a 200 nm NW that was well precharacterized using transmission electron microscope (TEM) measurements were determined using the four-probe method, the two-probe EMF across ∇T measurement, and the 3ω technique, respectively. The integrated TE properties represented by the figure of merit ZT (S2σT/κ) were found to be in good agreement with a theoretical study of Bi2Se3 NW.

Magnetic and dielectric phases like CoFe2O4 and BaTiO3 are both intrinsically capable of absorbing electromagnetic waves. The characteristics of the two phases in a composite structure to obtain the combined effect of the existence of phases as composite components have been investigated. Observation of the microstructure of composites with the composition (1-x)BaTiO3-(x)CoFe2O4 has shown the compact structure of composite sample with an increased the mass density with increasing value of x. No changes in lattice constant of each phase in the composite structure. This ensures that no complete or partial substitution between the ions of each phase has occurred. However, the presence of a material phase in the composite structure influenced the crystallite growth behavior of each phase. The mean crystallite size of the two phases tends to increase, but grew with a different rate. The saturation magnetization value of the composite samples is composition dependent. The value of remanent magnetization and coercivity increases with increasing values of x. All composite samples based on the results of data evaluation data taken by a vector network analyzer (VNA) in X-band frequency, shows the ability to absorb electromagnetic waves in all X-band frequencies. Composite composition determined the peak frequency that gives the maximum reflection loss value. The largest maximum reflection loss value is-40 dB occurring at a frequency of 10.98 GHz from samples with a composition x = 0.5. In conclusion, the composite of CoFe2O4/BaTiO3 system composite can be a promising candidate for electromagnetic wave dampers when the composite is properly designed.

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