Effect of Magnesium Addition on the Cell Structure of Foams Produced From Re-melted Aluminum Alloy Scrap

Closed-cell foams were produced from re-melted aluminum alloy scrap that contained 0.13 wt pct Mg magnesium in the as-received state and higher levels after adding 1, 2, or 5 wt pct Mg. The excess Mg gave rise to the fragmentation of long oxide filaments present in the scrap alloy into smaller filaments and improved its distribution and wetting by the Al matrix. Foaming the re-melted scrap alloy containing 1, 2, and 5 wt pct Mg excess showed stability and good expansion in comparison to the scrap alloy containing 0.13 wt pct Mg only, but the cells became non-equiaxed when the Mg concentration was high (≥2 wt pct excess) due to cell wall rupture during solidification. Compressibility and energy absorption behavior were studied for scrap alloy foams containing 1 wt pct Mg excess, which is the optimum level to obtain good expansion, stability, and uniform cell size. Foams with densities in the range of 0.2 to 0.4 g cm−1 produced by holding at the foaming temperature for different times were used for the investigation. A uniform cell structure led to flatter stress plateaus, higher energy absorption efficiencies, and reduced “knockdown” in strength compared with commercial foams made by gas bubbling. The mechanical performance found is comparable to that of commercial foams made by a similar method but the expected costs are lower

GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries

FIRST SEARCHES FOR OPTICAL COUNTERPARTS TO GRAVITATIONAL-WAVE CANDIDATE EVENTS

During the LIGO and Virgo joint science runs in 2009-2010, gravitational wave (GW) data from three interferometer detectors were analyzed within minutes to select GW candidate events and infer their apparent sky positions. Target coordinates were transmitted to several telescopes for follow-up observations aimed at the detection of an associated optical transient. Images were obtained for eight such GW candidates. We present the methods used to analyze the image data as well as the transient search results. No optical transient was identified with a convincing association with any of these candidates, and none of the GW triggers showed strong evidence for being astrophysical in nature. We compare the sensitivities of these observations to several model light curves from possible sources of interest, and discuss prospects for future joint GW-optical observations of this type

Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

The ERP system impact on the role of accountants

Purpose - The purpose of this paper is to discuss the impact of an Enterprise Resources Planning (ERP) system on the role of accountants, to provide job qualifications for their reference. Design/methodology/approach - This research adopts the case study method, using on-the-spot interviews and a questionnaire to find out the effects of an ERP system on the role of accountants. Findings - The role of accountants is mainly to be transaction data handlers and financial report providers. Clearly, accountants must have certain degree of knowledge in the realm of traditional finance accounting. In addition, accounting supervisors think implementing an ERP system changes the role of accountants. Research limitations/implications - The data collected by the authors are mainly from the Shanghai Financial Center and regional businesses in Shanghai, Beijing and Taiwan. The authors are only able to study the impact of ERP systems on the role of accountants in the short-term rather than in the long-term. Originality/value - It is widely accepted that an ERP system is more than just an accounting information system, so implementing an ERP system will not necessarily promote the positions of the accounting department and accountants on the subjective cognition of accountants. Accountants need to have knowledge of financial accounting, IT and management after ERP implementation

Universal Newborn Screening for Severe Combined Immunodeficiency (SCID)

Transplantation and immunomodulatio

Studies on growth, mortality and stock assessment of Indian mackerel, <em>Rastrelliger kanagurta</em> (Cuvier, 1817) from Ratnagiri coast of Maharashtra, India

2382-2385Study on the growth and mortality parameters of Indian mackerel, Rastrelliger kanagurta has been carried out based on the length frequency data.  Asymptotic length ((L∞)) and growth coeffient (K) were estimated as 320 mm and 1.87 yr-1 respectively.  Total, natural and fishing mortalities were 8.28, 2.64 and 5.64 yr-1 respectively. The exploitation rate (U) and exploitation ratio (E) were calculated as 0.68 and 0.69 respectively. As the exploitation ratio (E) is below the Emax (0.772) indicating that further increase in efforts can bring more catch of mackerel along the Ratnagiri coast

<span style="font-size:15.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:Mangal; color:black;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language: AR-SA" lang="EN-US">Stock Assessment of white fish, <i style="mso-bidi-font-style:normal">Lactarius lactarius</i> (Bloch and Schneider,1801) along Ratnagiri Coast of Maharashtra, India</span>

115-117<span style="font-size:9.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;color:black;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa;mso-bidi-font-weight:bold"="" lang="EN-US">The study on the age, growth and mortality of <span style="font-size:9.0pt; line-height:115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;color:black;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="" lang="EN-US">white fish<span style="mso-bidi-font-weight: bold">, Lactarius lactarius was carried out based on the length frequency data collected during August 2009 to August 2011. The asymptotic length ((L∞)) and growth coefficient (K) were estimated as 366 mm and 0.685 yr-1 respectively. The total, natural and fishing mortalities were 3.31, 1.30 and 2.01 yr-1 respectively. The exploitation rate (U) and exploitation ratio (E) were calculated as 0.61 and 0.62 respectively. Though Emax obtained at 0.91, it is not advisable for a stock to be exploited at that level as in future, it would be detrimental.</span