3,475 research outputs found
High Field Magneto-Conductivity Analysis of Bi2Se3 Single Crystal
We report the high field (up to 14Tesla) magneto-conductivity analysis of
Bi2Se3 topological insulator grown via the self flux method. The detailed
experimental investigations including crystal growth as well as the electrical,
thermal and spectroscopic characterizations of the resultant Bi2Se3 single
crystal are already reported by some of us. The current letter deals with high
field magneto-conductivity analysis in terms of Hikami Larkin Nagaoka (HLN)
model, which revealed that the electronic conduction is dominated by both
surface states driven weak anti localization (WAL), as well the bulk WL (weak
localization) states. Further, by applying the HLN equation we have extracted
the fitting parameters i.e., phase coherence length and the pre-factor. The HLN
equation exhibited values of [pre factor close to -1.0, indicating both WAL and
WL contributions. On the other hand, the extracted phase coherence length is
seen to decrease from 11.125 nm to 5.576 nm as the temperature is increased
from 5K to 200K respectively. Summarily, the short letter discusses primarily
the temperature dependent magneto-conductivity analysis of pristine Bi2Se3
single crystal by the HLN model.Comment: Letter to Editor MS: 10 pages including 3 Fig
Crystal Growth and Characterization of Bulk Sb2Te3Topological Insulator
The Sb2Te3 crystals are grown using the conventional self flux method via
solid state reaction route, by melting constituent elements (Sb and Te) at high
temperature (850 C), followed by slow cooling (2 C per hour).The weak anti
localization (WAL) related low field (2 Tesla) magneto-conductance at low
temperatures (2.5 K and 20 K) has been analysed and discussed using the Hikami-
Larkin - Nagaoka (HLN) model. Summarily, the short letter reports an easy and
versatile method for crystal growth of bulk Sb2Te3 topological insulator (TI)
and its brief physical property characterization.Comment: 18 Pages Text + Figs: Accepted Mat. Res. Exp. (May 2018
Transglossic language practices : young adults transgressing language and identity in Bangladesh
University of Technology, Sydney. Faculty of Arts and Social Sciences.The thesis provides a counter narrative to the prevailing discourses in Bangladesh that have shown increased concern about the detrimental effect of English on Bangla, the national language, and Bangladeshi identity. It is commonly assumed that young adults are subjugated by the colonial legacy of English, and they are consequently portrayed as passive recipients of popular culture. They are also criticized for their failure to maintain a domain-specific demarcated use of language, that is, English for academic purposes and socioeconomic advancements, and Bangla for local, cultural, and national activities.
Identifying that these key assumptions understate the complexities of young adults’ language practices and identity, the thesis offers a critical understanding of the role of English and Bangla in young adults’ lives. Drawing on insights from Pennycook’s transgressive approach to language and Bakhtin’s ‘heteroglossia’, the thesis proposes the notion of transglossia. Going beyond the overt dependence on linguistic features, transglossia appears to have the potential to reveal a sophisticated understanding of language. On the one hand, it provides a theoretical grounding to address the transgression observable in language in the mixing of codes, modes, genres, and a variety of cultural semiotic resources. On the other hand, as a conceptual proposition, it has the capacity to untangle the social, historical, political, ideological, and spatial nature of language. In addition, with its analytical framework, transglossia brings out the values, vested interests, and politics behind language-, class-, and gender-based identifications.
The data are drawn from a three-month long ethnographic research project which included observations, casual face-to-face conversations, virtual conversations on Facebook, interviews, and focus-group discussions of 29 students at a university in Bangladesh. Based on the analysis, the thesis argues in favour of understanding language and identity not in terms of formal systems, such as English or Bangla per se, but in terms of transglossia. Young adults actively and reflexively engage with mixtures of codes, modes, genres, and stylisation and pragmatically recontextualise popular cultural texts in their transglossic language practices within the historical and spatial realities of their lives. Ultimately, this thesis advances the recent theorisation of translingual practices in applied linguistics. It also contributes to the field by providing glimpses of the sociocultural dynamics of language in the post-colonial context of Bangladesh, a country very much under-represented in sociolinguistics research
High Field (up to 140kOe) Angle Dependent Magneto Transport of Bi2Te3 Single Crystals
We report the angle dependent high field (up to 140kOe) magneto transport of
Bi2Te3 single crystals, a well-known topological insulator. The crystals were
grown from melt of constituent elements via solid state reaction route by
self-flux method. Details of crystal growth along with their brief
characterization up to 5 Tesla applied field was reported by some of us
recently [J. Magn. Mag. Mater. 428, 213 (2017)]. The angle dependence of the
magneto-resistance (MR) of Bi2Te3 follows the cos Theta function i.e., MR is
responsive, when the applied field is perpendicular (tilt angle Theta = o
and/or 180) to the transport current. The low field (10 kOe) MR showed the
signatures of weak anti localization (WAL) character with typical cusp near
origin at 5 K. Further, the MR is linear right up to highest applied field of
140 kOe. The large positive MR are observed up to high temperatures and are
above 250 and 150 percent at 140 kOe in perpendicular fields at 50 K and 100 K
respectively. Heat capacity CP(T) measurements revealed the value of Debye
temperature to be 135 K. ARPES (angle resolved photoemission spectroscopy) data
clearly showed that the bulk Bi2Te3 single crystal consists of a single Dirac
cone.Comment: 13 Pages text + Figs... Letter - Mat. Res. Ex
Efectos inducidos por el hábitat sobre mutaciones y perfil de ácidos grasos en carpas mrigala que habitan en el fondo del río Chenab
Fish from the river Chenab were analyzed for DNA damage by the Comet and Micronucleus assays. The fatty acid profile was determined by gas chromatography using a Flame Ionization Detector. Atomic absorption spectrophotometry showed significant (p < 0.05) levels of contamination due to Cd, Hg, Cu, Mn, Zn, Pb, Cr, Sn and phenols in the fish habitat. The Comet assay revealed significant (p < 0.05) DNA damage in Cirrhinus mrigala of 37.29±2.51%, 34.96±2.53% and 38.80±2.42% in the comet tail, in the tail moment of 23.48±3.90, 19.78±4.26 and 14.30±1.82, in the olive moment of 16.22±2.04, 13.83±1.96 10.99±0.90, respectively, from three experimental sites. The micronucleus assay showed a high frequency of single micronucleus induction of 44.80±3.73, double induction of 06.20±0.97 and nuclear abnormalities of 09.60±1.72, as calculated in a thousand cells. C8:0, C12:0, C20:0, C16:1(n-7), C16:1(n-9), C20:1(n-9), C18:2(n-6), C18:4(n-3), C20:5(n-3), C22:4(n-6) fatty acids were found missing in the fish with a higher intensity of DNA damage but were found in optimal amounts both in farmed and wild fish from non polluted habitats. A highly significant (p < 0.01) correlation was also found in saturated, unsaturated fatty acids and DNA damage and habitat. The present study revealed that the habitat of even lower intensity pollutions not only induce DNA damage but also confiscate essential fatty acids of the omega series and reduce the amount of unsaturated fatty acids for which fish is preferred over other animals.Los daños en el ADN de los peces del río Chenab se analizaron mediante la técnica del “ensayo del cometa” y el ensayo de micronúcleos. El perfil de ácidos grasos se determinó mediante cromatografía de gases con detector de ionización de llama. La espectrofotometría de absorción atómica mostró diferencias significativas (p < 0.05) de los niveles de contaminación por Cd, Hg, Cu, Mn, Zn, Pb, Cr, Sn y fenoles en el hábitat de los peces. El ensayo del cometa mostró daños significativos (p < 0,05) en el ADN de las carpas mrigala de tres sitios experimentales: 37,29±2,51%, 34,96±2,53 y 38,80±2,42% del ADN en la cola del cometa, momento de la cola con 23,48±3,90, 19,78±4,26 y 14,30±1,82% y cola media con 16,22±2,04, 13,83±1,96 10,99±0,90. Los ensayos de micronúcleos mostraron una alta frecuencia de inducción de micronúcleos como única 44,80±3,73, 06,20±0,97 y doble anomalías nucleares 09,60±1,72 calculados en miles de células. C8:0, C12:0, C20:0, C16:1(n-7), C16:1 (n-9), C20:1(n-9), C18:2(n-6), C18:4(n-3), C20:5(n-3) y C22:4(n-6) se mostraron como ácidos grasos que faltan en el pescado que tiene una mayor intensidad de daño en el ADN, aunque se encuentran en cantidades óptimas, tanto en los peces de piscifactoría como en los salvajes donde no hay hábitats contaminados. Se encontró una correlación altamente significativa (p < 0,01) también en ácidos saturados, ácidos grasos insaturados, daño del ADN y hábitat. El presente estudio reveló que la intensidad de la contaminación del hábitat aún en la más baja no sólo induce daño en el ADN, sino también en la composición de los ácidos grasos de la serie omega y de los ácidos grasos insaturados, para los que se prefiere ingerir pescado a otros animales
Exact Static Cylindrical Solution to Conformal Weyl Gravity
We present the exact exterior solution for a static and neutral cylindrically
symmetric source in locally conformal invariant Weyl gravity. As a special case
the general relativity analogue still can be attained, however only as a
sub-family of solutions. Our solution contains a linear term that would thus
result in a potential that grows linearly over large distances. This may have
implications for exotic astrophysical structures as well as matter fields on
the extremely small scale.Comment: 8 pages, Physical Review
Genetic Analysis for the Diagnosis of Disorders of Sexual Development in Indonesia
Disorders of sex development (DSD) is defined by congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical, while in clinical practice this term means any abnormality of the external genitalia. DSD patients have been managed by a multidisciplinary gender team in our center as collaboration between Dr. Kariadi province referral hospital and Faculty of Medicine Diponegoro University. Diagnosis should be established by specific physical examination hormonal, chromosomal and DNA studies; and imaging for most of the cases depending on indication.Since 2004 the involvement of molecular and cytogenetic analysis so far can diagnosed many of the DSD cases. Most of the genetically proven cases were Congenital Adrenal hyperplasia, Androgen Insensitivity syndrome and sex chromosomal DSD that lead abnormal gonadal development. Many of them remain undiagnosed, further testing such as advanced DNA study should be carried out in collaboration with other center in overseas.The novel genes were found in some cases that contributed for the management of DSD. Information for medical professionals, patients, family members and community about the availability and necessity of DSD diagnosis should be delivered to improve DSD management and patient quality of life
- …