Gas rich galaxies from the FIGGS survey

The FIGGS (Faint Irregular Galaxy GMRT Survey) is aimed at creating a multi-wavelength observational data base for a volume limited sample of the faintest gas rich galaxies. In this paper we discuss two very gas rich galaxies that were observed as part of the FIGGS survey, viz. NGC 3741 and And IV. These galaxies are unusual in that they have extremely extended gas disks and very high ratios of dark to luminous matter. The very extended HI disks provide an unique opportunity to trace the extended distribution of dark matter around faint galaxies. We compare the baryon fraction of these galaxies with a sample of galaxies with well measured rotation curves and discuss whether extremely gas rich dwarf galaxies have abnormally small baryon fractions.Comment: 5 Pages, 4 Figures. To be published in the proceedings of "Galaxies in the Local Volume", ed. B. Koribalski, H. Jerje

Young researchers of the Barents Region

publishedVersio

The Impact of Remittances on Education Attainment: Evidence From Dominican Republic

This paper will examine the relationship between remittances and education attainment focusing on Dominican Republic in 2002. This study will focus on households in Dominican Republic using surveys from IPUMS international and the data is cross-sectional. Sending remittances increases the income for households, which in return, influences the spending on education. The study of remittances is analyzed in a more cultural and social value rather than entirely economic. The dynamic and structure of a family is crucial when studying the effects of remittances in a developing country. Key findings from this analysis is that the relationship between education attainment and remittances are positively related and it is statistically significant according to this model. This study examines the family structure as well as the economic and social structure of Dominican Republic to understand the relationship between remittances and education attainment

Thick gas discs in faint dwarf galaxies

We determine the intrinsic axial ratio distribution of the 'gas' disks of extremely faint M_B > -14.5 dwarf irregular galaxies. We start with the measured (beam corrected) distribution of apparent axial ratios in the HI 21cm images of dwarf irregular galaxies observed as part of the Faint Irregular Galaxy GMRT Survey (FIGGS). Assuming that the disks can be approximated as oblate spheroids, the intrinsic axial ratio distribution can be obtained from the observed apparent axial ratio distribution. We use a couple of methods to do this, and our final results are based on using Lucy's deconvolution algorithm. This method is constrained to produce physically plausible distributions, and also has the added advantage of allowing for observational errors to be accounted for. While one might a priori expect that gas disks would be thin (because collisions between gas clouds would cause them to quickly settle down to a thin disk), we find that the HI disks of faint dwarf irregulars are quite thick, with mean axial ratio ~ 0.6. While this is substantially larger than the typical value of ~ 0.2 for the 'stellar' disks of large spiral galaxies, it is consistent with the much larger ratio of velocity dispersion to rotational velocity (sigma/v_c) in dwarf galaxy HI disks as compared to that in spiral galaxies. Our findings have implications for studies of the mass distribution in and the Tully - Fisher relation for faint dwarf irregular galaxies, where it is often assumed that the gas is in a thin disk.Comment: 5 pages, 4 figures. Minor changes in revised version. The definitive version is available at http://www.blackwell-synergy.com

Building Information Modeling as Tool for Enhancing Disaster Resilience of the Construction Industry

As frequencies of the disasters are increasing, new technologies can be used to enhance disaster resilience performance of the construction industry. This paper investigates the usage of BIM (Building Information Modeling) in enhancing disaster resilience of the construction industry and in the establishment of the resilient built environment. In-depth literature review findings reveal BIM’s contribution to the disaster resilience in the pre-disaster and post-disaster phases especially through influencing the performance of the supply chain, construction process, and rescue operations. This paper emphasises the need for BIM’s integration to the education and training curriculums of the built environment professionals. Policy makers, construction professionals, professional bodies, academics can benefit from this research

Proofs of Some Conjectures of Chan on Appell-Lerch Sums

On page 3 of his lost notebook, Ramanujan defines the Appell-Lerch sum $$\phi(q):=\sum_{n=0}^\infty \dfrac{(-q;q)_{2n}q^{n+1}}{(q;q^2)_{n+1}^2},$$ which is connected to some of his sixth order mock theta functions. Let $\sum_{n=1}^\infty a(n)q^n:=\phi(q)$. In this paper, we find a representation of the generating function of $a(10n+9)$ in terms of $q$-products. As corollaries, we deduce the congruences $a(50n+19)\equiv a(50n+39)\equiv a(50n+49)\equiv0~(\textup{mod}~25)$ as well as $a(1250n+250r+219)\equiv 0~(\textup{mod}~125)$, where $r=1$, $3$, and $4$. The first three congruences were conjectured by Chan in 2012, whereas the congruences modulo 125 are new. We also prove two more conjectural congruences of Chan for the coefficients of two Appell-Lerch sums.Comment: 14 page

SPATIAL DIMENSION OF SOCIAL EXCLUSION. AN IMPERIAL INVESTIGATION INTO THE RELATIONSHIP OF HOUSING AND SOCIAL EXCLUSION IN THE SLUMS OF DHAKA CITY

Slums are perceived to be heavily populated urban areas characterized by inadequate access to safe water, hygienic sanitation, urban roads, legitimate power supply, poor structural quality of housing and insecure residential status. From that perspective, slums are the clear manifestation of urban poverty. This article emphasize that slums are not just simple expression of poverty but there is a causal process that leads to poverty and inequality. It is not a mere static state describing the inequality rather it is an outcome of structural process causing a chain of disadvantages and deprivations of the community living in the slums. In view of this, this article commences by outlining the key elements of housing in slums and through empirical findings summarises how each of these elements relate to the processes and outcomes involved in social exclusion. Findings from questionnaire interview and in-depth discussion with slum dwellers tend to lend credence to the drawing of a spatial margin of social exclusion. It is understood that slum dwellers’ socio-economic deprivation is closely related with housing elements that further leads to their segregation in social and economic life - thus invigorating a vicious cycle. The systematic exploitation, material deprivation leads to social and economic marginalization of the poor people and results in greater vulnerability of this marginalized group.Social Exclusion, spatial dimension, slums, Dhaka, Housing.

Employment Generation and Poverty Alleviation through SME Cluster Development in Bangladesh

SME Cluster Development could be an emerging force of entrepreneurship development, employment generation and poverty alleviation for any least developed country like Bangladesh. SMEs located at different clusters of Bangladesh are contributing in generating employment and income for the workers and producing import substitute product simultaneously. Realizing the full potential of SME cluster development in Bangladesh, it is important for all stakeholders to sit together and find out a concrete solution for the identified challenges of SME clusters. Recommended action plan could be catalyst to enhance productivity, increase efficiency, quality, acceptability, market linkage of SME products of Bangladesh. The action plan is designed with Short term (up to 3 year), Mid-term (3-5 years) and Long term (5 and more) recommendations for fostering cluster development of SME in Bangladesh with a vision of employment generation and poverty alleviation. 

The central surface density of "dark halos" predicted by MOND

Prompted by the recent claim, by Donato et al., of a quasi-universal central surface density of galaxy dark matter halos, I look at what MOND has to say on the subject. MOND, indeed, predicts a quasi-universal value of this quantity for objects of all masses and of any internal structure, provided they are mostly in the Newtonian regime; i.e., that their mean acceleration is at or above a0. The predicted value is qSm, with Sm= a0/2 pi G= 138 solar masses per square parsec for the nominal value of a0, and q a constant of order 1 that depends only on the form of the MOND interpolating function. This gives in the above units log(Sm)=2.14, which is consistent with that found by Doanato et al. of 2.15+-0.2. MOND predicts, on the other hand, that this quasi-universal value is not shared by objects with much lower mean accelerations. It permits halo central surface densities that are arbitrarily small, if the mean acceleration inside the object is small enough. However, for such low-surface-density objects, MOND predicts a halo surface density that scales as the square root of the baryonic one, and so the range of the former is much compressed relative to the latter. This explains, in part, the finding of Donato et al. that the universal value applies to low acceleration systems as well. Looking at literature results for a number of the lowest surface-density disk galaxies with rotation-curve analysis, I find that, indeed, their halo surface densities are systematically lower then the above "universal" value. The prediction of Sm as an upper limit, and accumulation value, of halo central surface densities, pertains, unlike most other MOND predictions, to a pure "halo" property, not to a relation between baryonic and "dark matter" properties.Comment: 9 page