Electronic structure and magnetism in doped semiconducting half-Heusler compounds

We have studied in details the electronic structure and magnetism in M (Mn and Cr) doped semiconducting half-Heusler compounds FeVSb, CoTiSb and NiTiSn (XM$_{x}$Y$_{1-x}$Z) in a wide concentration range using local-spin density functional method in the framework of tight-binding linearized muffin tin orbital method(TB-LMTO) and supercell approach. Our calculations indicate that some of these compounds are not only ferromagnetic but also half-metallic and may be useful for spintronics applications. The electronic structure of the doped systems is analyzed with the aid of a simple model where we have considered the interaction between the dopant transition metal (M) and the valence band X-Z hybrid. We have shown that the strong X-d - M-d interaction places the M-d states close to the Fermi level with the M-t$_{2g}$ states lying higher in energy in comparison to the M-e$_{g}$ states. Depending on the number of available d-electrons, ferromagnetism is realized provided the d-manifold is partially occupied. The tendencies toward ferromagnetic(FM) or antiferromagnetic(AFM) behavior are discussed within Anderson-Hasegawa models of super-exchange and double-exchange. In our calculations for Mn doped NiTiSn, the strong preference for FM over AFM ordering suggests a possible high Curie temperature for these systems.Comment: 14 pages, 6 figure

Pengaruh Konflik Kerja-keluarga dan Kepuasan Kerja terhadap Tingkat Turnover Intention Karyawan pada Restoran Pizza Hut Mall Bali Galeria

This study was conducted to determine the effect of work-family conflict and job satisfaction on turnover intention. This study is done at Pizza Hut Mall Bali Galeria. Samples taken as many as 60 people with saturated sample method, in which the saturated sample here using the entire population there as a sample. Data was collected through questionnaires using a 5-point Likert scale. The analysis technique used is the path analysis. The results of this study indicate that each variable lonflik work-family and job satisfaction effect on turnover intention in Restaurant Pizza Hut Mall Bali Galeria and indirect effect of work-family conflict on turnover intention through job satisfaction. It shows that work-family conflict negatively affect job satisfaction, and a positive effect on turnover intention. Job satisfaction can reduce the level of turnover intention of employees in the restaurant Pizza Hut Mall Bali Galeri

Time for pulse traversal through slabs of dispersive and negative (ϵ\epsilon, μ\mu) materials

The traversal times for an electromagnetic pulse traversing a slab of dispersive and dissipative material with negative dielectric permittivity ($\epsilon$) and magnetic permeability ($\mu$) have been calculated by using the average flow of electromagnetic energy in the medium. The effects of bandwidth of the pulse and dissipation in the medium have been investigated. While both large bandwidth and large dissipation have similar effects in smoothening out the resonant features that appear due to Fabry-P\'{e}rot resonances, large dissipation can result in very small or even negative traversal times near the resonant frequencies. We have also investigated the traversal times and Wigner delay times for obliquely incident pulses and evanescent pulses. The coupling to slab plasmon polariton modes in frequency ranges with negative $\epsilon$ or $\mu$ is shown to result in large traversal times at the resonant conditions. We also find that the group velocity mainly contributes to the delay times for pulse propagating across a slab with n=-1. We have checked that the traversal times are positive and subluminal for pulses with sufficiently large bandwidths.Comment: 9 pages, 9 figures, Submitted to Phys. Rev.

Electronic structure of half-metallic magnets

We have analyzed the electronic structure of half-metallic magnets based on first principles electronic structure calculations of a series of semi-Heusler alloys. The characteristic feature of the electronic structure of semi-Heusler systems is a d-d gap in the density of states lying at/close to the Fermi level depending on the number of valence electrons. We have employed various indicators of chemical bonding to understand the origin of the gap in these systems, which is crucial for their half-metallic property. The density of states of other half-metallic magnets also supports a gap and it is a generic feature of these systems. We have discussed in some details the origin of magnetism, in particular, how the presence of the gap is crucial to stabilize half-metallic ferro and ferri magnetism in these systems. Finally, we have studied the role of magnetic impurities in semiconducting semi-Heusler systems. We show with the aid of model supercell calculations that these systems are not only ferromagnetic but also half-metallic with possibly high Curie temperature.Comment: 7 pages, 6 figure

Effect of Consumer Ethnocentrism and Perceived Quality of Product on Buying Behavior of Domestic and Foreign Food Products: a Case Study in Pekanbaru, Riau, Indonesia

Due to the entry of foreign food products, not only domestic food products does Indonesia provide to the consumers, but also foreign food products. This study aimed to analyze the effects of consumer ethnocentrism and perceived quality product on the buying behavior of domestic and foreign food products. This study used cross-sectional design study involving data from 100 consumers of Bawah Market Pekanbaru who were chosen by convenience sampling technique. The results showed that the respondents had a medium level of consumer ethnocentrism. They perceived the quality of domestic food products higher than that of foreign food products. The results of the multinomial logistic regression test showed that ethnocentrism and perceived quality of domestic food products had a significant negative effect on the food product purchases. Specifically, consumers who had a higher level of ethnocentrism were less likely to purchase foreign food products. Meanwhile, consumers who had a higher level of perceived quality of domestic food product were less likely to purchase the mixture of domestic and foreign food products.Keywords: ethnocentrism, buying behavior, perceived quality of the product Masuknya produk makanan luar negeri ke Indonesia menyediakan konsumen alternatif bagi produk dalam negeri. Penelitian ini bertujuan untuk menganalisis pengaruh etnosentrisme konsumen dan persepsi kualitas produk terhadap perilaku pembelian produk makanan dalam dan luar negeri. Penelitian ini menggunakan desain cross sectional study dengan data yang diperoleh dari 100 orang konsumen di Pasar Bawah Pekanbaru yang dipilih menggunakan convenience sampling technique. Hasil penelitian menunjukkan etnosentrisme konsumen pada umumnya mencapai tahap sedang. Persepsi kualitas produk makanan dalam negeri lebih tinggi daripada persepsi kualitas produk makanan luar negeri. Hasil uji regresi logistik multinomial menunjukkan bahwa etnosentrisme dan persepsi kualitas produk dalam negeri memengaruhi pembelian produk makanan secara signifikan dan negatif. Konsumen yang memiliki etnosentrisme yang tinggi kurang cenderung untuk membeli produk luar negeri. Demikian juga, konsumen dengan persepsi kualitas produk dalam negeri yang tinggi kurang cenderung untuk membeli produk campuran dalam dan luar negeri

EKSPERIMENTASI MEDIA PEMBELAJARAN BERBASIS RPG (ROLE PLAYING GAME) DENGAN MENGGUNAKAN METODE INSTRUCTIONAL GAMES DAN TEAMS GAMES TOURNAMENTS PADA PEMBELAJARAN IPA SISWA KELAS VII SMPN 2 TUNTANG KABUPATEN SEMARANG

Penelitian ini bertujuan untuk mengetahui ada tidaknya perbedaan kemampuan kognitif antara siswa yang diajar dengan penggunaan media pembelajaran game edukasi berbasis Role Playing Game (RPG) dengan metode Instructional Games dan Teams Games Tournaments materi Kalor dan Perpindahannya pada siswa SMP kelas VII. Metode penelitian yang digunakan adalah metode eksperiment. Penelitian ini dilaksanakan di SMP N 2 Tuntang. Populasi dalam penelitian ini adalah semua siswa kelas VII SMP N 2 Tuntang Tahun Ajaran 2015/2016 yang terdiri dari 7 kelas. Teknik pengambilan sampel yang digunakan adalah cluster random sampling. Sampel yang digunakan dalam penelitian ini sebanyak 2 kelas, yaitu kelas VIIA dan VIIB, yang masing-masing terdiri dari 32 siswa. Teknik pengambilan data dilakukan dengan teknik dokumentasi dan tes. Teknik dokumentasi digunakan untuk memperoleh data keadaan awal siswa yang diambil dari nilai Fisika hasil tes tengah semester I, sedangkan teknik tes untuk memperoleh data kemampuan kognitif IPA siswa pada pokok bahasan Kalor dan Perpindahannya. Teknik analisis data yang digunakan dalam penelitian ini adalah dengan uji t-test satu ekor. Dari analisis data diperoleh hasil terdapat perbedaan rerata kemampuan kognitif antara penggunaan media pembelajaran game RPG(Roleplaying Game) pada metode Instructional Games dan Teams Games Tournaments pada materi Kalor dan Perpindahannya siswa kelas VII SMPN 2 Tuntang. Hal ini ditunjukkan oleh nilai signifikansi 0,002 (<0,05). Kata kunci: Game edukasi, Instructional Games, Teams Games Tournaments, Kalor dan Perpindahannya, RP