118 research outputs found
Rotation Curve with MOND and Dark Matter Halo profile for ESO138-G014
This paper is devoted to solve the galactic rotation problem for ESO138-G014
galaxy based on two theories: dark matter and Modified Newtonian Dynamics. Here
we did the rotation curve analysis with two possible choices for the dark
matter density profile, namely Burkert and Navarro, Frenk and White profiles.
The analysis shows the dark matter distribution favored to Burkert profile
(cored dark matter). The standard hypothesis for most spiral galaxies are known
to be embedded in dark matter haloes has now been overshadowed by Modified
Newtonian Dynamics, known as MOND, the leading alternative of dark matter. MOND
addresses the problem of a new fundamental constant , called the
acceleration constant, at which acceleration scale of Newton second law fails
to hold. In this respect, we investigate this issue by testing the rotation
curve within the MOND framework with the observations to obtain the reliable
disk mass, . We investigate whether ESO138-G014 is compatible with MOND or
dark matter is still favorable for the galactic rotation problem.Comment: 6 pages, 2 tables, 9 figure
Dark Matter in the Central Region of NGC 3256
We investigated the central mass distribution of the luminous infrared galaxy
NGC 3256 at a distance of 35 Mpc by using CO(1-0) observations of the Atacama
Large Millimeter and sub-millimeter Array (ALMA) and near-IR data of the Two
Micron Sky Survey (2MASS). We found that there is a huge amount of invisible
dynamical mass () in the central region of the
galaxy. The invisible mass is likely caused by some dark matter, which might
have a cuspy dark matter profile. We note that this dark matter is difficult to
explain with the conventional Modified Newtonian Dynamics (MOND) model, which
is only applicable at a low acceleration regime, whereas the acceleration at
the central region of the galaxy is relatively strong. Therefore, this
discovery might pose a challenge to the conventional MOND models.Comment: 26 pages, 7 figures, accepted by Sains Malaysian
From culture to innovate product : batik design in porcelain wares / Nurul ‘Ayn Ahmad Sayuti ... [et al.]
In this paper, the Batik Merbok motifs are proposed to be used in porcelain wares using 3D (CAD) software. The natural motifs developed are seen to have potential to be incorporated in tableware collections or as a daily home-product usage. It is a conceptual paper which explaining the
motifs developed by Batik Merbok and discussing the 3D (CAD) design developments. The motifs were developed with a combination of flora, fauna and the humanmade historical artefacts which were inspired from the surrounding areas of Merbok, Kedah. A detail research results are not yet conclusive; therefore, the researchers will continue to develop the porcelain wares further and investigate the consumer perceptions towards the incorporation of the batik motifs. It is one of the sole efforts of bringing Batik Merbok into exploring another genre of designs
Pultruded Kenaf Fibre Reinforced Composites: Effect of Different Kenaf Fibre Yarn Tex
AbstractManufacturing high performance composites from natural fibres is one of an ambitious goal currently being pursued by researchers across the globe. The ecological benefits of this material among many others are environmentally friendly and do not cause health problems. In terms of sustainability, the natural fibre is an appropriate alternative candidate to replace the synthetic and other types of reinforcement since it is a renewable resource. In order for natural fibre reinforced composite to become competitive, it has to accommodate the processing avenues of which has long being associated with its synthetic counterpart. Among those proven technology in manufacturing advanced engineering component is pultrusion. In this paper, an attempt has been made to produce pultrudedkenaf fibre reinforced unsaturated polyester composites via pultrusion. The properties of the pultrudedkenaf fibre reinforced composites with different kenaf yarn sizes are reported and compared. Pultruded composites made with smaller tex number i.e. tex 1400 shows better compression properties of as compared to larger tex number. Smaller tex number help to produce better wetting on fibre during production of composites, consequently help to increase its properties. Pultruded composites made with smaller tex number i.e. tex 1400 shows better compression properties of as compared to larger tex number. Smaller tex number help to produce better wetting on fibre during production of composites, consequently help to increase its properties
Preliminary proteomic characterisation of primodia and vegetative dikaryotic mycelial cells from tiger’s milk mushroom (Lignosus rhinocerus)
Tiger’s Milk mushrooms (Lignosus rhinocerus) are polypores with three distinct parts: cap (pileus), stem (stipe) and tuber (sclerotium). The stem of this medicinal mushroom is centrally connected to the brownish woody cap that grows out from the tuber underground rather than from the wood. To date, the biotic and abiotic factors that induce the growth of this mushroom are unclear and information regarding its development is scanty. Hence, the differential protein expressions of vegetative dikaryotic mycelial and primordial cells of this mushroom were investigated. Six two dimensional-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (2D-SDS-PAGE) of 13 cm with pH3-10 containing the intracellular proteins of vegetative mycelial and primordial cells of L. rhinocerus were obtained. Analysis of 2D-SDS-PAGE using Progenesis Samespot version 4.1 yielded approximately 1000 distinct protein spots in the proteome of vegetative mycelial cells, while primordial proteome contained nearly 100 spots. Further comparison between the vegetative mycelial and primordial proteomes yielded significant up-regulation of protein expression of 5 primordial cells proteins that were labeled as P1, P2, P3, P4 and P5. These protein spots were excised, trypsin digested and submitted to mass spectrometry. Protein identification through MASCOT yielded significant identification with P1 and P2 as DnaJ domain protein, P3 and P5 as hypothetical protein while P4 as AP-2rep transcription factor. The present results suggested that P3, P4 and P5 are novel proteins that involved in the initiation of L. rhinocerus primordia. Our findings also suggested that stress response mechanism is present during fruitification of this mushroom
Concentric circles and spiral configurations for large correlator arrays in radio astronomy
Aperture synthesis arrays are commonly used in radio astronomy to take images of radio point sources, with the planned Square Kilometre Array (SKA) being the most common example. One approach to enhancing the quality of the images is to optimize an antenna array configuration in a possible SKA implementation. An ideal arrangement must ensure optimal configurations to capture a clear image by either decreasing the sidelobe level (SLL) in the l-m domain or increasing the sampled data in the spatial-frequency domain. In this paper a novel configuration is considered to optimize the array by considering all possible observation situations through the positions of the antenna array elements via a mathematical model that we call geometrical method (GM). To demonstrate its efficiency, the technique is applied to developing an optimal configuration for the elements of the Giant Metrewave Radio Telescope (GMRT). The effect of these changes, particularly in the forms of circular and spiral arrangements, is discussed. It is found that a spiral configuration results in fewer overlapping samples than the number of antennas placed along three arms of the GMRT with fewer than 11% and 27% overlapping samples in the snapshot and 6 hr tracking observations, respectively. Finally, the spiral configuration reduces the first SLL from -13.01 dB, using the arms of the current GMRT configuration, to - 15.64 dB.Web of Science1564art. no. 17
Agarwood Induction: Current Developments and Future Perspectives
Agarwood is a resinous part of the non-timber Aquilaria tree, which is a highly valuable product for medicine and fragrance purposes. To protect the endangered Aquilaria species, mass plantation of Aquilaria trees has become a sustainable way in Asian countries to obtain the highly valuable agarwood. As only physiologically triggered Aquilaria tree can produce agarwood, effective induction methods are long sought in the agarwood industry. In this paper, we attempt to provide an overview for the past efforts toward the understanding of agarwood formation, the evolvement of induction methods and their further development prospects by integrating it with high-throughput omics approaches
Archetypal myth: goddess Durga and the resilient matriarch in Rani Manicka's The Rice Mother
Ruthless victimization of women is often depicted in Malaysian fiction. Characterized by biasness and brutalities of a predominantly male-centred culture, this theme has been a central theme by writers coming from varied cultural and ethnic backgrounds that makeup Malaysia. Rani Manicka also incorporates such theme in her debut novel, The Rice Mother (2003). However, another theme that becomes prominent in this novel is the theme of resiliency – portrayed mainly through the matriarch figure, Lakshmi. Indeed, Lakshmi’s resilience has interesting affinity with Durga, a principal form of the Hindu goddess, and it is against this mythological archetype that we frame the reading of the novel. Ultimately, an understanding of this mythological archetype will provide a clearer lens with which to look at Manicka’s story, and thus, the reader will be able to see how she presents the greater purpose of this archetype: to promote the resiliency of the human spirit
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