The Deepest Supernova Search is Realized in the Hubble Ultra Deep Field Survey

The Hubble Ultra Deep Field Survey has not only provided the deepest optical and near infrared views of universe, but has enabled a search for the most distant supernovae to z~2.2. We have found four supernovae by searching spans of integrations of the Ultra Deep Field and the Ultra Deep Field Parallels taken with the Hubble Space Telescope paired with the Advanced Camera for Surveys and the Near Infrared Multi Object Spectrometer. Interestingly, none of these supernovae were at z>1.4, despite the substantially increased sensitivity per unit area to such objects over the Great Observatories Origins Deep Survey. We present the optical photometric data for the four supernovae. We also show that the low frequency of Type Ia supernovae observed at z>1.4 is statistically consistent with current estimates of the global star formation history combined with the non-trivial assembly time of SN Ia progenitors.Comment: 24 pages (6 figures), submitted to the Astronomical Journa

Surface Relaxation Mechanisms in the Morphological Equilibration of Crystal Surfaces

The phenomenology of surface relaxation below the roughening temperature TR is shown via kinetic Monte Carlo simulation to exhibit extremely non-classical behavior depending on (1) initial morphology and (2) kinetic rate laws for atom motion. However, within the temperature and size scale of our simulations there are several different mechanisms that operate. The “pinch-off” mechanism is seen to be operative for ripple relaxation employing i-kinetics. For ripple relaxation employing ∆i-kinetics, pinch-off is seen at short times. At long times, these particular surfaces spontaneously island, and then reduction of line tension drives relaxation. Reduction of line tension also drives relaxation of dimpled surfaces.Engineering and Applied Science

Identifying prognostic indicators for electrical treeing in solid insulation through pulse sequence analysis

Predictive maintenance attempts to evaluate the condition of equipment and predict the future trend of the equipment's aging, in order to reduce costs when compared to the two traditional approaches: corrective and preventive maintenance. This prediction requires an accurate prognostic model of aging. In solid insulation, the ultimate goal of prognostics is to predict the advent of failure, i.e., insulation breakdown, in terms of remaining useful life (RUL). One fault is electrical treeing, which is progressive thus leading to potentially catastrophic failure. Research has shown that diagnosis of faults can be achieved based on partial discharge (PD) monitoring [1], i.e., phase-resolved and pulse sequence analysis (PSA). This work will explore the extension of this concept towards predicting evolution of the defect: moving beyond diagnostics towards prognostics. To do this, there is a need for further investigation of prognostic features within PD characteristics leading up to breakdown. In this work, a needle-plane test arrangement was set up using a hypodermic needle and pre-formed silicone rubber as test samples. The visual observations and tree growth measurements were made using a digital microscope. PD data was captured using a radio frequency (RF) sensor and analysed using PSA. The main idea of the PSA approach is the strong relationship between two consecutive pulses caused by PD activities, which can give an understanding of the local degradation processes [1]. As for electrical treeing, a breakdown indicator in PSA is the appearance of heavily clustered data points that lie diagonally in scatter plots of the differential ratio of voltage and time of consecutive charges (Un = Δun/Δtn) [2,3]. Figure 1 shows an example of a plot that changed to a diagonal line after 14 hours of aging time. This paper investigates the formation of the diagonal line based on the distribution of the plot from the start of electrical treeing until breakdown occurs. Finally, statistical features of the PSA plot are given and will be used for lifetime prediction of insulation samples in future work

Analysis of Grouper Business Development in Gerokgak District, Buleleng Regency, Bali Province

Fisheries development is a human effort in increasing the utilization of all fishery\u27s biological resources which include the fishery capture, aquaculture, and processing sectors. Grouper is a commodity that has high economic value, but the amount of aquaculture production is still low, one of which is in Gerokgak district.This research was conductedfrom February to March 2018, in Gerokgak District, Buleleng Regency,Bali Province. Dataobtainedthrough interviews, observations, documentation, and questionnaires directly with respondents, namely the Department of Maritime Affairs and Fisheries of Buleleng Regency, business owners, managers, and grouper farmers. The analysis used in this study was toobtaina grouper cultivation strategy using a SWOT analysis. From the results of the calculation of the analysis and determination of the SWOT matrix,thewgovernment must increase grouper aquaculture results by increasing the number of hatchery and enlargement businesses. The government is more responsive to the problems faced by farmers

Etnogenesis dan Kehidupan Keagamaan Migran Muslim di Malaysia

The dynamics of religious life and the formation of ethnic identity after Malaysia independence is the starting point of this paper. Malaysias rapid economic development in 1970s invites Indonesia labor migration and other Asian countries like India, Bangladesh and Myanmar, which then bring together with them the religious culture of their homeland and significant changes in the religious discourse of citizens. This article made from the research that has been conducted on religious lives of two migrant communities in Malaysia and aimed to describe the relationship between religious lives of citizens below the Islamic Malay ethno genesis which took place under the Malaysian nation-state regime. Although the migrants and citizens both are Muslims, this study shows the home for both sides precisely in the transnational missionary movements, especially, Tablighi Jamaat which will be further elaborated after the next discussion of this article. Keywords: Kehidupan keagamaan, Migran, Etnogenesis

Angular dependence of domain wall resistivity in artificial magnetic domain structures

We exploit the ability to precisely control the magnetic domain structure of perpendicularly magnetized Pt/Co/Pt trilayers to fabricate artificial domain wall arrays and study their transport properties. The scaling behaviour of this model system confirms the intrinsic domain wall origin of the magnetoresistance, and systematic studies using domains patterned at various angles to the current flow are excellently described by an angular-dependent resistivity tensor containing perpendicular and parallel domain wall resistivities. We find that the latter are fully consistent with Levy-Zhang theory, which allows us to estimate the ratio of minority to majority spin carrier resistivities, rho-down/rho-up~5.5, in good agreement with thin film band structure calculations.Comment: 14 pages, 3 figure

Differential medial temporal lobe morphometric predictors of item- and relational-encoded memories in healthy individuals and in individuals with mild cognitive impairment and Alzheimer's disease.

INTRODUCTION:Episodic memory processes are supported by different subregions of the medial temporal lobe (MTL). In contrast to a unitary model of memory recognition supported solely by the hippocampus, a current model suggests that item encoding engages perirhinal cortex, whereas relational encoding engages parahippocampal cortex and the hippocampus. However, this model has not been examined in the context of aging, neurodegeneration, and MTL morphometrics. METHODS:Forty-four healthy subjects (HSs) and 18 cognitively impaired subjects (nine mild cognitive impairment [MCI] and nine Alzheimer's disease [AD] patients) were assessed with the relational and item-specific encoding task (RISE) and underwent 3T magnetic resonance imaging. The RISE assessed the differential contribution of relational and item-specific memory. FreeSurfer was used to obtain measures of cortical thickness of MTL regions and hippocampus volume. RESULTS:Memory accuracies for both item and relational memory were significantly better in the HS group than in the MCI/AD group. In MCI/AD group, relational memory was disproportionately impaired. In HSs, hierarchical regressions demonstrated that memory was predicted by perirhinal thickness after item encoding, and by hippocampus volume after relational encoding (both at trend level) and significantly by parahippocampal thickness at associative recognition. The same brain morphometry profiles predicted memory accuracy in MCI/AD, although more robustly perirhinal thickness for item encoding (R2 = 0.31) and hippocampal volume and parahippocampal thickness for relational encoding (R2 = 0.31). DISCUSSION:Our results supported a model of episodic memory in which item-specific encoding was associated with greater perirhinal cortical thickness, while relational encoding was associated with parahippocampal thickness and hippocampus volume. We identified these relationships not only in HSs but also in individuals with MCI and AD. In the subjects with cognitive impairment, reductions in hippocampal volume and impairments in relational memory were especially prominent