Search

The Cayley sum graph is a graph whose vertex comprises elements of an abelian group G, and edges are the sum of these vertices belonging to a subset of G, namely, S. We introduce the Cayley sum signed graph by giving the sign to these edges. An edge receives a positive sign if any of the incident vertices belong to S. Otherwise, it receives a negative sign. We discuss the properties of the Cayley sum signed graph. [ABSTRACT FROM AUTHOR]

This paper's aim to characterise the 18th CE Palm leaf manuscript of India's southern and eastern part based on its structural elements. Investigative studies were carried using polarised light microscope and stereomicroscope for the samples drawn from Indian states of Kerala, Tamil Nadu and Odisha. From the data, it is observed that the palm leaf species of Borassus and Corypha mostly drawn from southern and eastern states of India were extensively exploited for manuscript writing in whole of India. The microscopic observation also showed the weak zones present in the palm leaf manuscripts for suitable conservation measures. [ABSTRACT FROM AUTHOR]

Temperature-dependent ferroelectric behavior in Ba0.85Ca0.15Ti0.9−xFexZr0.1O3 (BCT-BZT-Fe) (x = 0%, 0.5%, 1%) has been investigated. Olsen cycle is used to estimate the thermal energy conversion potential in the compositions under study. The maximum energy conversion density of 305 kJ/m3 per cycle is obtained for BCT-BZT-Fe (0.5% Fe content) when the cycle is operated between 30 and 110 °C and an electric field of 0-3 MV/m. The obtained energy density is very high for small electric field and temperature gradient as compared to other lead-free ferroelectric materials. A comparison table of previously reported Olsen cycle-based energy conversion in bulk ferroelectric ceramics is presented. Temperature also affects the hysteresis parameters, therefore, scaling relations for coercive field (Ec) and remnant polarization (Pr) as a function of temperature (T) were also observed. The power-law exponents are obtained for all hysteresis parameters in the compositions under study. The scaling relations are found as Ec ∝ T−0.658, Ec ∝ T−0.687 and Ec ∝ T−0.717 for 0%, 0.5% and 1% Fe, respectively. Similarly, Pr ∝ T−1.59, Pr ∝ T−1.65 and Pr ∝ T−1.85 are for 0%, 0.5% and 1% Fe, respectively. Additionally, back-switching polarization (Pbc) behavior as a function of temperature is estimated by well-described Arrhenius law to evaluate the average activation energy for all the compositions. [ABSTRACT FROM AUTHOR]