Halogenation of SiC for band-gap engineering and excitonic functionalization

The optical excitation spectra and excitonic resonances are investigated in systematically functionalized SiC with Fluorine and/or Chlorine utilizing density functional theory in combination with many-body perturbation theory. The latter is required for a realistic description of the energy band-gaps as well as for the theoretical realization of excitons. Structural, electronic and optical properties are scrutinized and show the high stability of the predicted two-dimensional materials. Their realization in laboratory is thus possible. Huge band-gaps of the order of 4 eV are found in the so-called GW approximation, with the occurrence of bright excitons, optically active in the four investigated materials. Their binding energies vary from 0.9 eV to 1.75 eV depending on the decoration choice and in one case, a dark exciton is foreseen to exist in the fully chlorinated SiC. The wide variety of opto-electronic properties suggest halogenated SiC as interesting materials with potential not only for solar cell applications, anti-reflection coatings or high-reflective systems but also for a possible realization of excitonic Bose-Einstein condensation

Dynamic sorted neighborhood indexing for real-time entity resolution

Real-time Entity Resolution (ER) is the process of matching query records in subsecond time with records in a database that represent the same real-world entity. Indexing techniques are generally used to efficiently extract a set of candidate records from the database that are similar to a query record, and that are to be compared with the query record in more detail. The sorted neighborhood indexing method, which sorts a database and compares records within a sliding window, has been successfully used for ER of large static databases. However, because it is based on static sorted arrays and is designed for batch ER that resolves all records in a database rather than resolving those relating to a single query record, this technique is not suitable for real-time ER on dynamic databases that are constantly updated. We propose a tree-based technique that facilitates dynamic indexing based on the sorted neighborhood method, which can be used for real-time ER, and investigate both static and adaptive window approaches. We propose an approach to reduce query matching times by precalculating the similarities between attribute values stored in neighboring tree nodes. We also propose a multitree solution where different sorting keys are used to reduce the effects of errors and variations in attribute values on matching quality by building several distinct index trees. We experimentally evaluate our proposed techniques on large real datasets, as well as on synthetic data with different data quality characteristics. Our results show that as the index grows, no appreciable increase occurs in both record insertion and query times, and that using multiple trees gives noticeable improvements on matching quality with only a small increase in query time. Compared to earlier indexing techniques for real-time ER, our approach achieves significantly reduced indexing and query matching times while maintaining high matching accuracy

Parameter Genetik Sifat Pertumbuhan Dan Kerapatan Kayu Klon Eucalyptus Pellita F. Muell. Di Dua Tapak Yang Berbeda Di Kalimantan Timur

Industrial forest plantations have an important role in fulfilling the wood demand. Based on global industrial development, the forest plantations industry will increase in the following years. Eucalyptus pellita has become main species in Indonesia forest plantations because it has a short cycle and wood products are suitable to forest industry. The average productivity of E. pellita plantations in Indonesia is still low and high variation. In an effort to increase the productivity, the first step is a better understanding of genetic control on growth and basic density. This study aims to determine the genetic parameters for growth and basic density of E. pellita clones on two different sites. The clonal trials was conducted at two different sites. Both clonal trial are designed using RCBD. The number of clones tested in both trial was 30, 5 blocks and 25 tree/plot. The result of the study showed that the effects of clones vary greatly according the enviromental conditions. The clones- environemntal interaction of growth trait is higher than the basic density. This is in line with genetic parameters of growth trait that are less stable than the basic density. The expected genetic gain of growth trait is higher than the basic density and at the same time there was a weak genetic correlation (there is even a negative) between growth trait and basic density. Therefore carefulness is needed in selecting clones when the two traits are used as selection parameters

Pengaruh Konsentrasi Chemical Oxygen Demand (Cod) Dan Ragi Terhadap Kinerja Granular Activated Carbon Dual Chamber Microbial Fuel Cells (Gac-dcmfcs)

Microbial fuel cell jika digunakan dalam pengolahan limbah, mampu menghasilkan energi yang bersih sebagai bagian dari pengolahan limbah yang efektif. Namun, beberapa hal yang sangat mempengaruhi kinerja MFC seperti komunitas mikroorganisme dan substrat belum ditemukan titik optimumnya. Penelitian ini menjawab tantangan tersebut dengan mengembangkan sebuah sistem MFC dengan menggunakan variasi konsentrasi COD dan ragi dalam mempengaruhi kinerja MFC. Limbah artifisial digunakan sebagai substrat MFCs karena diinginkan konsentrasi yang sesuai dengan tujuan penelitian. Media filter Granular activated carbon digunakan sebagai media perlekatan bakteri dalam pembentukan biofilm sehingga meningkatkan efisiensi penyisihan kontaminan. Variasi konsentrasi COD yang digunakan adalah 400, 800 dan 1200 mg/l dan konsentrasi ragi 1,5; 3 dan 4,5 g/l yang dioperasikan dalam kondisi batch selama proses seeding dan aklimatisasi dan kontinyu setelah proses aklimatisasi. Penyisihan COD tertinggi dihasilkan oleh reaktor 1200 mg/l dengan penambahan ragi 4,5 g/l yaitu sebesar 5624,6 mg/l atau sebesar 98,2%. Produksi listrik tertinggi dihasilkan pada konsentrasi 800 mg/l dan ragi 3 g/l dengan nilai 281,01 mW/m2. Dari perbandingan semua konsentrasi ragi dan COD, dapat disimpulkan bahwa pada range COD 800 – 1200 mg/l dan ragi 3 – 4,5 g/l microbial fuel cells menghasilkan penurunan COD dan produksi listrik yang optimum. Hasil menunjukkan bahwa metabolisme dan aktivitas mikroorganisme dalam biofilm sangat mempengaruhi kondisi operasional reaktor GACMFC

In-situ Magnesium Diboride Superconducting Thin Films grown by Pulsed Laser Deposition

Superconducting thin films of MgB2 were deposited by Pulsed Laser Deposition on magnesium oxide and sapphire substrates. Samples grown at 450C in an argon buffer pressure of about 10-2 mbar by using a magnesium enriched target resulted to be superconducting with a transition temperature of about 25 K. Film deposited from a MgB2 sintered pellet target in ultra high vacuum conditions showed poor metallic or weak semiconducting behavior and they became superconducting only after an ex-situ annealing in Mg vapor atmosphere. Up to now, no difference in the superconducting properties of the films obtained by these two procedures has been evidenced.Comment: 10 pages, 4 figure

Distribution of vacA genotypes in Helicobacter pylori strains isolated from Brazilian adult patients with gastritis, duodenal ulcer or gastric carcinoma

This PCR-based analysis is the first molecular epidemiological study in Brazil testing Helicobacter pylori cagA and vacA distribution in adults with gastric complaints, that includes a large number of carcinoma patients. Multiple-strain infection was identified in 11/13.4% patients. vacA sl-ml and cagA(+) genotypes were the most common in patients with a non-mixed infection. All vacA s1 strains were s1b, so subtyping s1 strains was not useful. vacA s1b-m1 and cagA(+) strains were associated with higher prevalence of peptic ulcer and gastric carcinoma than vacA s2-m2 and cagA(-) ones. in conclusion, cagA and vacA genotyping may have clinical relevance in Brazil. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.Univ Fed Minas Gerais, Mol Biol Lab, Fac Med, BR-30130100 Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Lab Res Bacteriol, Fac Med, BR-30130100 Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Dept Pathol, Fac Med, BR-30130100 Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol, BR-04023062 São Paulo, BrazilUniv Fed Rio de Janeiro, Inst Microbiol Prof Paulo de Goes, BR-21941590 Rio de Janeiro, BrazilUniv Itauna, Fac Fisioterapia, BR-35680033 Itauna, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol, BR-04023062 São Paulo, BrazilWeb of Scienc

‘Ethnic group’, the state and the politics of representation

The assertion, even if only by implication, that ‘ethnic group’ categories represent ‘real’ tangible entities, indeed identities, is commonplace not only in the realms of political and policy discourse but also amongst contemporary social scientists. This paper, following Brubaker (2002), questions this position in a number of key respects: of these three issues will dominate the discussion that follows. First, there is an interrogation of the proposition that those to whom the categories/labels refer constitute sociologically meaningful ‘groups’ as distinct from (mere) human collectivities. Secondly, there is the question of how these categories emerge, i.e. exactly what series of events, negotiations and contestations lie behind their construction and social acceptance. Thirdly, and as a corollary to the latter point, we explore the process of reification that leads to these categories being seen to represent ‘real things in the world’ (ibid.)

Vestibular Stimulation for ADHD: Randomized Controlled Trial of Comprehensive Motion Apparatus

Objective: This research evaluates effects of vestibular stimulation by Comprehensive Motion Apparatus (CMA) in ADHD. Method: Children ages 6 to 12 (48 boys, 5 girls) with ADHD were randomized to thrice-weekly 30-min treatments for 12 weeks with CMA, stimulating otoliths and semicircular canals, or a single-blind control of equal duration and intensity, each treatment followed by a 20-min typing tutorial. Results: In intent-to-treat analysis (n = 50), primary outcome improved significantly in both groups (p = .0001, d = 1.09 to 1.30), but treatment difference not significant (p = .7). Control children regressed by follow-up (difference p = .034, d = 0.65), but overall difference was not significant (p = .13, d = .47). No measure showed significant treatment differences at treatment end, but one did at follow-up. Children with IQ-achievement discrepancy ≥ 1 SD showed significantly more CMA advantage on three measures. Conclusion: This study illustrates the importance of a credible control condition of equal duration and intensity in trials of novel treatments. CMA treatment cannot be recommended for combined-type ADHD without learning disorder

Evidence of a dense water vein along the Libyan continental margin

For the first time it was possible to investigate a still poorly known region of the eastern Mediterranean Sea, the Libyan continental margin. An oceanographic cruise, performed during summer 2006, revealed an important and novel feature: a dense vein flowing along the continental slope. The paper describes the vein evolution with some insights on its dynamic and furnishes an estimate of its transport, which results to be comparable with the Adriatic Deep Water production rate. The cascading into a steep canyon which incises the continental shelf suggests that the vein may play an important role in ventilating the deep layers of the Ionian Sea

Ogbu and the debate on educational achievement: an exploration of the links between education, migration, identity and belonging

This paper looks at some of the issues raised by Ogbu’s work in relation to the education of different minority ethnic groups. Ogbu poses questions such as the value attached to education, its links to the future and its measurable outcomes in terms of ‘success’ as experienced by black participants. The desire for better life chances leads families to consider migration to a new country or resettlement within the same country, thus making migration both a local and a global phenomenon. As an example, attention is drawn to the situation facing South Asian children and their families in the UK. In terms of ethnicity and belonging, the wider question that is significant for many countries in the West after ‘Nine-Eleven’ is the education of Muslim children. A consideration of this current situation throws Ogbu’s identification of ‘autonomous minority’ into question. It is argued that a greater understanding of diverse needs has to be accompanied by a concerted effort to confront racism and intolerance in schools and in society, thus enabling all communities to make a useful contribution and to avoid the ‘risk’ of failure and disenchantment