The relationship between Mg II broad emission and quasar inclination angle

Several observed spectral properties of quasars are believed to be influenced by quasar orientation. In this investigation we examine the effect of orientation on the Mg II line located at 2798 {\AA} in a sample of 36 radio-loud quasars, with orientation angles having been obtained in a previous study using radio observations. We find no significant relationship between orientation angle and either Mg II line full-width at half-maximum or equivalent width. The lack of correlation with inclination angle contradicts previous studies which also use radio data as a proxy for inclination angle and suggests the Mg II emission region does not occupy a disk-like geometry. The lack of correlation with Mg II equivalent width, however, is reported in at least one previous study. Although the significance is not very strong (86 percent), there is a possible negative relationship between inclination angle and Fe II strength which, if true, could explain the Fe II anti-correlation with [O III ] strength associated with Eigenvector 1. Interestingly, there are objects having almost edge-on inclinations while still exhibiting broad lines. This could be explained by a torus which is either clumpy (allowing sight lines to the central engine) or mis-aligned with the accretion disk.Comment: Proceedings from the conference 'Quasars at all cosmic epochs' held in Padova, Italy (2-7 April 2017

The physical driver of the optical Eigenvector 1 in Quasar Main Sequence

Quasars are complex sources, characterized by broad band spectra from radio through optical to X-ray band, with numerous emission and absorption features. However, Boroson & Green (1992) used Principal Component Analysis (PCA), and with this analysis they were able to show significant correlations between the measured parameters. The leading component, related to Eigenvector 1 (EV1) was dominated by the anticorrelation between the Fe${\mathrm{II}}$ optical emission and [OIII] line and EV1 alone contained 30% of the total variance. It opened a way in defining a quasar main sequence, in close analogy to the stellar main sequence on the Hertzsprung-Russel (HR) diagram (Sulentic et al. 2001). The question still remains which of the basic theoretically motivated parameters of an active nucleus (Eddington ratio, black hole mass, accretion rate, spin, and viewing angle) is the main driver behind the EV1. Here we limit ourselves to the optical waveband, and concentrate on theoretical modelling the Fe${\mathrm{II}}$ to H$\mathrm{\beta}$ ratio, and we test the hypothesis that the physical driver of EV1 is the maximum of the accretion disk temperature, reflected in the shape of the spectral energy distribution (SED). We performed computations of the H$\mathrm{\beta}$ and optical Fe${\mathrm{II}}$ for a broad range of SED peak position using CLOUDY photoionisation code. We assumed that both H$\mathrm{\beta}$ and Fe${\mathrm{II}}$ emission come from the Broad Line Region represented as a constant density cloud in a plane-parallel geometry. We expected that a hotter disk continuum will lead to more efficient production of Fe${\mathrm{II}}$ but our computations show that the Fe${\mathrm{II}}$ to H$\mathrm{\beta}$ ratio actually drops with the rise of the disk temperature. Thus either hypothesis is incorrect, or approximations used in our paper for the description of the line emissivity is inadequate.Comment: 12 pages, 4 figures, Accepted for publication in the Journal Frontiers in Astronomy and Space Science

Using cases for school principal performance standards: Australian and New Zealand experiences.

This article reports an international validation of a framework for performance standards for school principals. The framework, generated in Australia in 1996-1997, was applied in New Zealand in 2000. The framework involved an innovative method of establishing standards for principals' performance, based on a combination of qualitative and quantitative methods of making judgements about the quality of principals' work. Using cases of critical incidents in which principals made decisions in their everyday work, the essential elements of quality performance, together with a set of dimensions on which performance varied, were identified. This study explored the application of these essential elements and dimensions in a context in which similar school system restructuring is in progress. Three questions were addressed: How valid are the Australian cases in the New Zealand setting? How applicable to the New Zealand setting are the three continua—ditties, interpersonal skills, moral dispositions—that comprise the framework? And finally, How applicable to the New Zealand setting are the particular duties, interpersonal skills and moral dispositions? This study supports three conclusions. First, cases generated in one context are not applicable in a different cultural setting. However, the method of developing cases is readily applied cross culturally. Second, the values underpinning the framework developed in Australia are similar to, but not the same as, those about which principals in New Zealand assess principal performance. Third, there are similarities, but also important subtle differences, in the particular dimensions on which the framework is grounded. The study indicates the validity of using cases to generate performance standards for school principals

ELECTROSPUN ETHYL CELLULOSE NANOFIBERS WITH PHASE CHANGE MATERIALS: DESIGNING TEMPERATURE-RESPONSIVE DRUG DELIVERY SYSTEMS

In this study, ethyl cellulose (EC) nanofibers loaded with either Rhodamine B (RhB) or Doxorubicin HCl (DOX) and phase change materials (PCM) were fabricated by blend electrospinning. EC is a cellulose derivative widely used as an excipient in the pharmaceutical industry and an ideal polymer for controlled drug release. Lauric acid (LA) and stearic acid (SA) were used as a material with a melting point close to physiological body temperature. Good drug-polymer compatibility and an amorphous distribution of drugs were shown by Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. The release rate of RhB was shown to be dependent on both drug and PCM loading at 37°C. Samples containing phase change material also showed an increased release rate of 8% RhB when the temperature was increased from 37 °C to 40 °C. A stimuli-controlled release of DOX was demonstrated by an increase of 27% and 41% release rate at pH 7.4 and pH 4, respectively, when the temperature was increased from 37 °C to 40 °C. The comparison of RhB and DOX showed the influence of the selected drug on release rate. The reported electrospun drug delivery system shows promise for the temperature-responsive release of DOX over an extended time-period. This approach may prove useful in the treatment of solid tumors while reducing side effects and improving patient compliance and outcomes

TINJAUAN KRIMINOLOGIS TERHADAP PENCURIAN DENGAN PEMBERATAN PADA RUMAH YANG DITINGGAL PERGI PEMILIKNYA (SUATU PENELITIAN DI WILAYAH HUKUM POLRESTA BANDA ACEH)

ABSTRAKWILDY ALHUMAIRA, TINJAUAN KRIMINOLOGIS TERHADAP 2018PENCURIAN DENGAN PEMBERATAN PADA RUMAH YANG DITINGGAL PERGI PEMILIKNYA (Suatu Penelitian di Wilayah Hukum Polresta Banda Aceh)Fakultas Hukum Universitas Syiah Kuala (iv, 60) pp,bibl.,tabl Mukhlis, S.H, M.HumBerdasarkan Pasal 363 ayat 1 ke-3, ke-4 dan ke-5 Kitab Undang-Undang Hukum Pidana (KUHP) disebutkan bahwa diancam pidana penjara paling lama 7 tahun terhadap pencurian yang dilakukan diwaktu malam hari dalam sebuah rumah, yang dilakukan oleh dua orang atau lebih, dengan merusak, memotong, memanjat, atau dengan memakai anak kunci palsu, perintah palsu atau pakaian jabatan palsu. Walaupun sudah diatur bahwa pencurian dengan pemberatan adalah perbuatan yang dilarang dan adanya sanksi akibat dari perbuatan tersebut namun pada kenyataannya kasus pencurian pada rumah yang ditinggal pergi pemiliknya masih terjadi.Tujuan penulisan skripsi ini untuk menjelaskan faktor penyebab terjadinya pencurian dengan pemberatan pada rumah yang ditinggal pergi pemiliknya, modus operandi pelaku dalam melakukan pencurian dengan pemberatan pada rumah yang ditinggal pergi pemiliknya dan upaya penanggulangan terhadap pencurian dengan pemberatan pada rumah yang ditinggal pergi pemiliknya.Data penulisan skripsi ini diperoleh melalui penelitian kepustakaan untuk dan memperoleh data sekunder dilakukan dengan cara mempelajari Kitab Undang-Undang Hukum Pidana, buku serta sumber-sumber lain yang berkaitan dengan pencurian dengan pemberatan pada rumah yang ditinggal pergi pemiliknya. Penelitian lapangan dilakukan untuk mendapatkan data primer melalui wawancara dengan responden dan informan.Hasil penelitian menunjukkan bahwa pencurian dengan pemberatan pada rumah yang ditinggal pergi pemiliknya tersebut terjadi karena faktor ekonomi, faktor pendidikan yang rendah, serta faktor adanya kesempatan.Modus operandi yang dilakukan pelaku dalam pencurian dengan pemberatan pada rumah yang ditinggal pergi pemiliknya yaitu dilakukan diwaktu malam hari, dengan cara memantau dan memilih lokasi yang strategis, dengan merusak pintu dan jendela agar bisa masuk ke dalam rumah. Upaya yang dapat dilakukan dalam menanggulangi pencurian dengan pemberatan pada rumah yang ditinggal pergi pemiliknya adalah dengan upaya pre-emtif, upaya preventif, dan upaya represif.Disarankan kepada pemerintah agar menyediakan lapangan kerja dan memberi bantuan kepada masyarakat yang kurang mampu, dan diharapkan adanya kesadaran hukum dari masyarakat dalam hal melaporkan suatu tindak pidana kepada pihak yang berwenang ketika terjadinya suatu tindak pidana khususnya pencurian dengan pemberatan

Virtual communities: the effect of technology on learning

Traditionally, concepts of communities have been grounded within a geographical framework. However, in a country as large as Australia, geographic connection between groups is not always physically possible. The developments in communication technology alleviate geographic and time issues. Universities in Australia have incorporated communication technology within their teaching practices to provide efficient teaching practices. However, whether communication solely through the virtual realm can be an effective replacement for face-to-face contact is a matter of debate. Some theorists argue that face-to-face engagement is the key to bringing experiences to life, while others maintain that the intellectual engagement that characterizes communications in the virtual world is an effective and meaningful form of communication. The experiences of external students and students who complement their studies with an online component are contrasted. The paper explores the factors associated with learning in a virtual realm and students' ability to engage not only with the intellectual content of their unit, but also with their university community

Quasar broad absorption line variability measurements using reconstructions of un-absorbed spectra

We present a two-epoch Sloan Digital Sky Survey and Gemini/GMOS+William Herschel Telescope/ISIS variability study of 50 broad absorption line quasars of redshift range 1.9 < z < 4.2, containing 38 Si IV and 59 C IV BALs and spanning rest-frame time intervals of approximately 10 months to 3.7 years. We find that 35/50 quasars exhibit one or more variable BALs, with 58% of Si IV and 46% of C IV BALs showing variability across the entire sample. On average, Si IV BALs show larger fractional change in BAL pseudo equivalent width than C IV BALs, as referenced to an unabsorbed continuum+emission-line spectrum constructed using non-negative matrix factorisation. No correlation is found between BAL variability and quasar luminosity, suggesting that ionizing continuum changes do not play a significant role in BAL variability (assuming the gas is in photoionization equilibrium with the ionizing continuum). A subset of 14 quasars have one variable BAL from each of Si IV and C IV with significant overlap in velocity space and for which variations are in the same sense (strengthening or weakening) and which appear to be correlated (98% confidence). We find examples of both appearing and disappearing BALs in weaker/shallower lines with disappearance rates of 2.3% for C IV and 5.3% for Si IV, suggesting average lifetimes of 142 and 43 years respectively. We identify 5 objects in which the BAL is coincident with the broad emission-line, but appears to cover only the continuum source. Assuming a clumpy inhomogeneous absorber model and a typical size for the continuum source, we infer a maximum cloud radius of 10^13 to 10^14 cm, assuming Eddington limited accretion.Comment: Accepted for publication in MNRAS. 22 pages, 12 figures, 7 table