Origin of the "Waterfall" Effect in Phonon Dispersion of Relaxor Perovskites

Inelastic neutron scattering study of the perovskite relaxor ferroelectric PZN:8%PT elucidates the origin of the previously reported unusual kink on the low frequency transverse phonon dispersion curve (known as "waterfall" effect). We show that its position depends on the choice of the Brillouin zone and that the relation of its position to the size of the polar nanoregions is highly improbable. The observation is explained in the framework of a simple model of coupled damped harmonic oscillators representing the acoustic and optic phonon branches.Comment: 4 pages, 6 figures, LaTe

Magnetic field enhanced structural instability in EuTiO_{3}

EuTiO_{3} undergoes a structural phase transition from cubic to tetragonal at T_S = 282 K which is not accompanied by any long range magnetic order. However, it is related to the oxygen ocathedra rotation driven by a zone boundary acoustic mode softening. Here we show that this displacive second order structural phase transition can be shifted to higher temperatures by the application of an external magnetic field (increased by 4 K for mu_{0}H = 9 T). This observed field dependence is in agreement with theoretical predictions based on a coupled spin-anharmonic-phonon interaction model.Comment: 4 pages, 4 figure

FAKTOR YANG BERHUBUNGAN DENGAN KEJADIAN INTRA UTERINE FETAL DEATH (IUFD) PADA IBU BERSALIN DI RSUD KOTA KENDARI

Intra Uterine Fetal Death (IUFD) atau kematian janin dalam kandungan adalah tidak adanya tanda-tanda kehidupan janin dan belum dikeluarkannya janin dari uterus ibunya. Intra Uterine Fetal Death (IUFD) merupakan salah satu penyebab kematian perinatal. Penelitian ini menggunakan metode deskriptif analitik dengan pendekatan cross sectional. Jumlah sampel 62 orang terbagi atas Kasus IUFD 31 orang dan Kontrol (Tidak IUFD) berjumlah 31 orang. Instrumen penelitian menggunakan lembar check list. Analisis data menggunakan uji Chi Square dan uji Mann Whitney U. Hasil Uji Chi Square hubungan umur ibu dengan kejadian IUFD didapatkan nilai p=0,27 (p>0,05) artinya tidak ada hubungan yang bermakna antara umur ibu dengan kejadian IUFD. Hasil Uji Chi Square hubungan paritas dengan kejadian IUFD didapatkan nilai p=0,00 (p<0,05) artinya ada hubungan yang bermakna antara paritas dengan kejadian IUFD. Hasil Uji Mann Whitney U hubungan umur kehamilan dengan kejadian IUFD diperoleh hasil p=0,01 (p<0,05) artinya ada hubungan yang bermakna antara umur kehamilan dengan kejadian IUFD. Kesimpulan: Tidak ada hubungan antara umur ibu dengan kejadian IUFD, ada hubungan antara paritas dan umur kehamilan dengan kejadian IUFD.   Kata Kunci: Umur Ibu, Paritas, Umur Kehamilan, IUFD

Utilization of Wastes as an Alternative Energy Source for Sustainable Development: A REVIEW

Generally, the greater the economic prosperity and the higher percentage of urban population, the greater the amount of solid waste produced. Reduction in the volume and mass of solid waste is a crucial issue especially in the light of limited availability of final disposal sites in many parts of the world. To meet the rising demand for energy and to address environmental concerns, a conversion from conventional energy systems to renewable resources is essential. For the sustainability of human civilization, an environmentally techno – economically feasible waste treatment method is very important to treat waste. Several technologies are available for converting solid waste to energy source, ranging from very simple systems of disposing of waste to more complex technologies capable of dealing with large amounts of industrial waste. There are three main pathways for conversion of waste material to energy: thermochemical, biochemical and physicochemical conversion. Therefore, this paper examines how waste can be utilized to produce energy for sustainable development with adequate use of science and technology. It is recommended that, awareness campaign should be carried out to enlighten the general populace on the benefit of utilizing waste to energy source.Keywords: Waste, sustainable development, utilisation, energy source

Anisotropic dielectric function in polar nano-regions of relaxor ferroelectrics

The paper suggests to treat the infrared reflectivity spectra of single crystal perovskite relaxors as fine-grained ferroelectric ceramics: locally frozen polarization makes the dielectric function strongly anisotropic in the phonon frequency range and the random orientation of the polarization at nano-scopic scale requires to take into account the inhomogeneous depolarization field. Employing a simple effective medium approximation (Bruggeman symmetrical formula) to dielectric function describing the polar optic modes as damped harmonic oscillators turns out to be sufficient for reproducing all principal features of room temperature reflectivity of PMN. One of the reflectivity bands is identified as a geometrical resonance entirely related to the nanoscale polarization inhomogeneity. The approach provides a general guide for systematic determination of the polar mode frequencies split by the inhomogeneous polarization at nanometer scale.Comment: 5 pages, 2 figure

Hybrid paramagnon phonon modes at elevated temperatures in EuTiO3

EuTiO3 (ETO) has recently experienced an enormous revival of interest because of its possible multiferroic properties which are currently in the focus of research. Unfortunately ETO is an unlikely candidate for enlarged multifunctionality since the mode softening - typical for ferroelectrics - remains incomplete, and the antiferromagnetic properties appear at 5.5K only. However, a strong coupling between lattice and Eu spins exists and leads to the appearance of a magnon-phonon-hybrid mode at elevated temperatures as evidenced by electron paramagnetic resonance (EPR), muon spin rotation ({\mu}SR) experiments and model predictions based on a coupled spin-polarizability Hamiltonian. This novel finding supports the notion of strong magneto-dielectric (MD) effects being realized in ETO and opens new strategies in material design and technological applications.Comment: 9 pages, 4 figure

Gas-phase Photocatalytic Oxidation of 1-Hexene Using Heterogeneous Semiconductor Materials

Photo-catalytic reactions have been carried out and proved to be conducted under mild conditions in contrast to several conventional industrial chemical processes, which involve the use of high amounts of temperature and pressure. In this work, an investigation of the photo-catalytic oxidation of 1-hexene was carried out using UVA-activated TiO2, and coupled TiO2/WO3 to drive organic reactions. Different mol % of WO3 ranging from 1-7mol% were used to monitor effect of coupling amount. The chosen photocatalyst was immobilized on glass beads using an innovative in-house procedure. The immobilized catalyst was then used in a vapour-phase flow reactor designed for alkene photo-oxidation studies. It was possible to establish oxidation rates of 0.14+-0.02 mmol/h for 1-hexene with TiO2/WO3 (1mol %). 1,2-epoxyhexane was successfully synthesized from 1-hexene achieving 15.9% conversion and 41% and 54% selectivity for the 1-hexene, 1,2-epoxyhexane and CO2 respectively when H2O/O2 was used as oxidant. Selectivity of 96% and 97% for CO2 were achieved with N2 and O2 respectively. No epoxide was formed with either N2 or O2 alone

Analysis of the Legal Consequences of Legalizing Polyandry Marriages in the Gorontalo Religious Court Area

The purpose of this research is to find out the Legal Consequences of Legalizing Polyandry Marriages in the Gorontalo Religious Court Area. In this research, the author uses normative research method or normative juridical research. This normative research includes library research or document study, because the object studied is in the form of public official documents, namely official data from the Gorontalo Religious Court. The results of this study researchers found preliminary data in the Gorontalo Religious Court, there is 1 (one) case of Itsbat Nikah application which is contrary to Article 3 and Article 9 of Law Number 1 of 1974 jo. Law Number 16 of 2019 concerning Marriage, as well as Article 40 of the Compilation of Islamic Law (KHI) but by the panel of judges the case was granted and there was 1 (one) itsbat nikah case Number 255/Pdt.P/2022/PA.Gtlo with the same type of application case but there were differences in the judge's consideration in deciding the case with the ruling not accepted