Obscuration by Gas and Dust in Luminous Quasars

We explore the connection between absorption by neutral gas and extinction by dust in mid-infrared (IR) selected luminous quasars. We use a sample of 33 quasars at redshifts 0.7 < z < 3 in the 9 deg^2 Bo\"otes multiwavelength survey field that are selected using Spitzer Space Telescope Infrared Array Camera colors and are well-detected as luminous X-ray sources (with >150 counts) in Chandra observations. We divide the quasars into dust-obscured and unobscured samples based on their optical to mid-IR color, and measure the neutral hydrogen column density N_H through fitting of the X-ray spectra. We find that all subsets of quasars have consistent power law photon indices equal to 1.9 that are uncorrelated with N_H. We classify the quasars as gas-absorbed or gas-unabsorbed if N_H > 10^22 cm^-2 or N_H < 10^22 cm^-2, respectively. Of 24 dust-unobscured quasars in the sample, only one shows clear evidence for significant intrinsic N_H, while 22 have column densities consistent with N_H < 10^22 cm^-2. In contrast, of the nine dust-obscured quasars, six show evidence for intrinsic gas absorption, and three are consistent with N_H < 10^22 cm^-2. We conclude that dust extinction in IR-selected quasars is strongly correlated with significant gas absorption as determined through X-ray spectral fitting. These results suggest that obscuring gas and dust in quasars are generally co-spatial, and confirm the reliability of simple mid-IR and optical photometric techniques for separating quasars based on obscuration.Comment: 5 pages, 3 figure

Towards visualisation of central-cell-effects in scanning-tunnelling-microscope images of subsurface dopant qubits in silicon

Atomic-scale understanding of phosphorous donor wave functions underpins the design and optimisation of silicon based quantum devices. The accuracy of large-scale theoretical methods to compute donor wave functions is dependent on descriptions of central-cell-corrections, which are empirically fitted to match experimental binding energies, or other quantities associated with the global properties of the wave function. Direct approaches to understanding such effects in donor wave functions are of great interest. Here, we apply a comprehensive atomistic theoretical framework to compute scanning tunnelling microscopy (STM) images of subsurface donor wave functions with two central-cell-correction formalisms previously employed in the literature. The comparison between central-cell models based on real-space image features and the Fourier transform profiles indicate that the central-cell effects are visible in the simulated STM images up to ten monolayers below the silicon surface. Our study motivates a future experimental investigation of the central-cell effects via STM imaging technique with potential of fine tuning theoretical models, which could play a vital role in the design of donor-based quantum systems in scalable quantum computer architectures.Comment: Nanoscale 201

The Role of the Fiscal Stimulus Program in Expanding Labor-intensive Infrastructure in Response to the Impact of the 2008/09 Global Financial Crisis

The global financial crisis (gfc) that swept over the world in 2008/09 had an influence on the Indonesian economy. in an attempt to reduce the impact of the gfc, the government introduced a fiscal stimulus program (fsp) in 2009 in order to encourage economic growth. the program consisted of two main elements, namely, tax cuts and increased government spending. this report presents the results of research into the implementation of the fsp, in terms of government spending to expand infrastructure in the context of reducing the impact of the crisis. the study, for which samples were selected in the kabupaten of demak, sragen, sukoharjo, and klaten (in Central Java) and the kabupaten of gowa, sinjai, and bulukumba (in South Sulawesi), was part of the activities involved in monitoring the socioeconomic impact of the gfc, which has been carried out by the smeru research institute since july 2009. this research was done in a qualitative way in order to obtain a general understanding of the impact of the gfc on the socioeconomic situation of the population, the process of formulation and decision-making in the implementation of the fsp, and the benefits of the fsp in overcoming the impact of the crisis on community livelihoods. on the whole, research findings indicated that fsp targets have not been in accordance with the impact of the gfc. although the gfc had a sufficiently significant effect on the national economy during the period from the end of 2008 until the middle of 2009, its impact on the economies of the study areas was relatively minor. the allocation of fsp funding for kabupaten and kota shows a wide variation and was not related to the level of impact of the gfc or to the economic position of the region that had been impacted. the fsp funds had already raised the capacity of development spending in the recipient regions and the expansion of infrastructure provided benefits to the local economy; however, the fsp did not contribute directly to the assistance of community members who had been affected by the crisis. keywords: global financial crisis, fiscal stimulus program, infrastructure developmen

Analysis of Resource-Use Efficiency in Dry Season Vegetable Production in Jere, Borno State, Nigeria

This study examined the resource-use efficiency in vegetable production in Jere   L.G.A. of Borno State, Nigeria. Data for the study were obtained from primary source with the aid of a structured questionnaire using the interview schedule. The data were for 2010 cropping season collected between October-December of 2010. Five villages notable for vegetables production were purposely chosen for the study and responses from 100 vegetable farmers from the four villages were used in the analyses. Production function analysis which incorporates the conventional neoclassical test of economic and technical efficiencies was used as the analytical technique. Findings revealed that seed (p&lt;0.01), land (p&lt;0.01), herbicide (p&lt;0.10) and pesticide (p&lt;0.01) significantly affected the vegetable output. And the farmers were inefficient in the use of all the resources. Farm inputs such as seed, land and pesticide were under-utilized while herbicide, fertilizer and labour were over-utilized. The study concludes that if additional units of seed, pesticide and land were available and accessible, it would lead to an increase in vegetable yield by 114.58, 322.64 and 568.72kg per hectare among the farmers respectively. The study suggests that there is need for making inputs such as improved seeds and herbicide affordable and accessible to the farmers so as to improve efficiency. Also policies that encourage the testing of soils fertility for fertilizer recommendations and creation of alternative employment opportunities to absorb the excess labour used in vegetable production in the area should be formulated. Key words: Resource-use, efficiency, production function, jere, vegetable, productio

Peningkatan Hasil Belajar Siswa Menggunakan Media Kartu Bilangan pada Pembelajaran Matematika di Kelas IV

Tujuan penelitian ini adalah “Untuk menganalisis penggunaan media kartu bilangan pada pelaksanaan pembelajaran bilangan romawi untuk meningkatkan hasil belajar siswa kelas IV Sekolah Dasar Negeri 24 Mempawah Hilir. Metode yang digunakan dalam penelitian ini menggunakan media kartu bilangan atau alat peraga. Alat peraga adalah untuk menurunkan keabstrakan dari konsep, agar siswa mampu menangkap arti sebenarnya dari konsep tersebut. Bentuk penelitian ini merupakan Penelitian Tindakan Kelas (PTK). Teknik dan alat pengumpulan data dalam penelitian ini adalah teknik observasi langsung dan lembar observasi langsung. Hasil pada penelitian ini dengan penggunaan media kartu bilangan dalam pembelajaran matematika dapat meningkatan hasil belajar siswa kelas IV Sekolah Dasar Negeri 24 Mempawah Hilir. Pada siklus I nilai ketuntasan siswa mencapai 13 orang siswa atau 81,25% dan pada siklus II mengalami peningkatan yaitu siswa yang mencapai nilai KKM sebanyak 15 orang siswa atau 93,75%. peningkatan dari siklus I ke siklus II yaitu sebesar 12,5%. Kata kunci : Hasil belajar, Kartu Bilangan, Pembelajaran matematika. Abstract: The purpose of this study is “to analyze the use of a media card numbers on the implementation of the roman numeral learning to improve student learning outcomes Elementary School fourth grade 24 downstream Mempawah. The method used in this study using a media card numbers or props. Props is to lower the abstractness of the concepts, so that students are able to capture the true meaning of the concept. This research forms a Classroom Action Research (CAR). Techniques and tools of data collection in this study is the technique of direct observation and direct observation sheet. The results in this study with the use of a media card numbers in mathematics learning can improve student learning outcomes Elementary School fourth grade 24 downstream Mempawah. In the first cycle of students achieving mastery value 13 students or 81.25 % and the second cycle increased ie students who reached the KKM many as 15 students or 93.75 %. Improvement from the first cycle to the second cycle is equal to 12.5 %

Grasslands Classification in Yobe State Nigeria Using Integrated Orderly Classification System of Grassland (IOCSG)

Integrated Orderly Classification System of Grassland (IOCSG) was initiated by Professor Ji-Zhou Ren in the 1960s and it has satisfactorily served to direct theory and practice of grassland classification for the last several decades in China. In this study IOCSG is adopted to classify the grasslands in Yobe state Nigeria, using 30 years (1984-2013) data on precipitation and temperature from 12 satellite stations across the state. Humidity (moisture index) was estimated as the ratio of precipitation per annum to annual temperature. The results revealed a trend of decline in precipitation and moisture index with latitude; from 772.63 mm and 0.72 in the south (110 08\u27 N) to 303.81 mm and 0.32 in the northern part of the state (130 27\u27 N), respectively. The average cumulative annual precipitation and moisture index in ten (10) of the stations ranges from 772.63 mm and 0.72 to 436.50 mm and 0.41 respectively. While the remaining two (2) stations recorded 407.77 and 303.81 mm as cumulative average precipitation as well as 0.38 and 0.28 as cumulative average annual moisture index. The Average cumulative annual temperature in the state was \u3e100000C across the stations. Two grassland class; Tropical arid and Tropical extra-arid grasslands were identified in the state at the first level of IOCSG. Therefore, tropical arid grassland management techniques should be fully employed for efficient utilization of grassland resources in the study area and further classification of the grasslands into subclasses using edaphic conditions, according to the IOCSG should be carried out