A Selected Ion Flow Tube Study of the Reactions of Several Cations with the Group 6B Hexafluorides SF6, SeF6, and TeF6

The first investigation of the ion chemistry of SeF$_6$ and TeF$_6$ is presented. Using a selected ion flow tube, the thermal rate coefficients and ion product distributions have been determined at 300 K for the reactions of fourteen atomic and molecular cations, namely H$_3$O$^+$, CF$_3^+$, CF$^+$, CF$_2^+$, H$_2$O$^+$, N$_2$O$^+$, O$^+$, CO$_2^+$, CO$^+$, N$^+$, N$_2^+$, Ar$^+$, F$^+$ and Ne$^+$ (in order of increasing recombination energy), with SeF$_6$ and TeF$_6$. The results are compared with those from the reactions of these ions with SF$_6$, for which the reactions with CF$^+$, CF$_2^+$, N$_2$O$^+$ and F$^+$ are reported for the first time. Several distinct processes are observed amongst the large number of reactions studied, including dissociative charge transfer, and F$^-$, F, F$_2^-$ and F$_2$ abstraction from the neutral reactant molecule to the reagent ion. The dissociative charge transfer channels are discussed in relation to vacuum ultraviolet photoelectron and threshold photoelectron-photoion coincidence spectra of XF$_6$ (X = S, Se, and Te). For reagent ions whose recombination energies lie between the first dissociative ionisation limit, XF$_6$ $\rightarrow$ XF$_5^+$ + F + e$^-$, and the onset of ionisation of the XF$_6$ molecule, the results suggest that if dissociative charge transfer occurs, it proceeds via an intimate encounter. For those reagent ions whose recombination energies are greater than the onset of ionisation, long-range electron transfer may occur depending on whether certain physical factors apply, for example non-zero Franck-Condon overlap. From the reaction kinetics, limits for the heats of formation of SeF$_4$, SeF$_5$, TeF$_4$ and TeF$_5$ at 298 K have been obtained; $\Delta_f$H$^o$(SeF$_4$) < -369 kJ mol$^{-1}$, $\Delta_f$H$^o$(SeF$_5$) < -621 kJ mol$^{-1}$, $\Delta_f$H$^o$(TeF$_4$) > -570 kJ mol$^{-1}$, and $\Delta_f$H$^o$(TeF$_5$) < -822 kJ mol$^{-1}$

Preliminary Test of Prescribed Burning for Control of Maple Leaf Cutter (Lepidoptera: Incurvariidae)

Leaf litter burning in the spring resulted in 87.5% mortality of maple leaf cutter pupae, Paraclemensia acerifoliella (Fitch). No apparent damage was observed on sugar maple or beech trees within the burn area

Faktor Faktor yang Mempengaruhi Minat Mahasiswa Akuntansi untuk Berkarir sebagai Akuntan Publik (Studi Kasus pada Perguruan Tinggi dengan Program Studi Akuntansi yang Berakreditasi B yang Terdapat di Pekanbaru)

This study aimed to examine the effect of; intrinsic factors of work, financial rewards, labor market consideration, work social values, professional training, and professional rewards in choosing career as public accountant. It is expected that this research can help the students in considering the career they will choose. The sample of this research is the accounting students in University of Riau (UR), State Islamic University (UIN), and Islamic University of Riau (UIR) in Pekanbaru. The data is collected by using questionnaire survey. From 100 questionnaires given, 100 questionnaires are given back to the researcher, and the totals of questionnaire that can be analyzed are 92 questionnaires. The data collected is analyzed by multiple regression by using SPSS version 17.0. The result of this research showed that intrinsic factors of work, financial rewards, consideration of labor market and professional training has influence in career choosing as public accountant. Whereas, work social values and professional rewards do not has influence in career choosing as public accountant.Keywords: accounting students, career choosing, and public accountant

Pengaruh Rasio Utang, Manajemen Laba, Kualitas Hasil Pemeriksaan dan Ukuran Perusahaan terhadap Kualitas Laporan Keuangan (Studi Empiris pada Perusahaan Property & Real Estate di Bursa Efek Indonesia Periode 2011-2013)

This study aims to obtain empirical evidence about the influence of leverage, earning management, quality of audit and firm size at quality of the financial statements are measured by an index of conservatism. The populations was property & real estate companies listed on the Stock Exchange 2011-2013 period. Determination of thesample is done by using purposive sampling method based on secondary data from financial reports that are available in the Indonesia Stock Exchange Website. There were about 96 companies selected ad the sample of the study. The method of analysis used was multiple linear regression analysis. The results of this study found that: Leverage and firm size has positive significant effect on the quality of financial statements, Earning management has negative significant effect on the quality of financial statements, Quality of audite not has effect on the quality of financial statements

Stripe phases in the two-dimensional Falicov-Kimball model

The observation of charge stripe order in the doped nickelate and cuprate materials has motivated much theoretical effort to understand the underlying mechanism of the stripe phase. Numerical studies of the Hubbard model show two possibilities: (i) stripe order arises from a tendency toward phase separation and its competition with the long-range Coulomb interaction or (ii) stripe order inherently arises as a compromise between itinerancy and magnetic interactions. Here we determine the restricted phase diagrams of the two-dimensional Falicov-Kimball model and see that it displays rich behavior illustrating both possibilities in different regions of the phase diagram.Comment: (5 pages, 3 figures

Magnetic and the magnetocaloric properties of Ce1-xRxFe2 and Ce(Fe1-xMx)2 compounds

We have studied selected rare earth doped and transition metal doped CeFe2 compounds by examining their structural, magnetic and magneto-thermal properties. With substitution of Ce by 5 and 10% Gd and 10% Ho, the Curie temperature can be tuned to the range of 267-318 K. Localization of Ce 4f electronic state with rare earth substitutions is attributed for the enhancement of Curie temperature. On the other hand, with Ga and Al substitution at the Fe site, system undergoes paramagnetic to ferromagnetic transition and then to an antiferromagnetic phase on cooling. The magnetocaloric effect across the transitions has been studied from both magnetization isotherms and heat capacity data. It is shown that by choosing the appropriate dopant and its concentration, the magnetocaloric effect around room temperature can be tuned.Comment: 13 pages, 6 figures, 2 table