Role of stress-assisted martensite in the design of strong ultrafine-grained duplex steels

This work explains the occurrence of transformation-induced plasticity via stress-assisted martensite, when designing ultrafine-grained duplex steels. It is found that, when the austenite is reduced to a fine scale of about 300 nm, the initial deformation-induced microstructure can be dominated by parallel lamellae of epsilon martensite or mechanical twinning, which cannot efficiently provide nucleation sites for strain-induced martensite. Hence, alpha martensite nucleation occurs independently by a stress-assisted process that enhances transformation-induced plasticity in ultrafine-grained austenite. This metallurgical principle was validated experimentally by using a combination of transmission Kikuchi diffraction mapping, transmission electron microscopy, and atom probe microscopy, and demonstrated theoretically by the thermodynamics model of stress-assisted martensite.The authors acknowledge the facilities, and the scientific and technical assistance of the Australian Microscopy & Microanalysis Research Facility (ammrf.org.au) node at Sydney Microscopy & Microanalysis, at the University of Sydney.This is the accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S1359645414006958

The 6-GHz multibeam maser survey III: comparison between the MMB and HOPS

We have compared the occurrence of 6.7-GHz and 12.2-GHz methanol masers with 22-GHz water masers and 6035-MHz excited-state OH masers in the 100 square degree region of the southern Galactic plane common to the Methanol Multibeam (MMB) and H2O southern Galactic Plane surveys (HOPS). We find the most populous star formation species to be 6.7-GHz methanol, followed by water, then 12.2-GHz and, finally, excited-state OH masers. We present association statistics, flux density (and luminosity where appropriate) and velocity range distributions across the largest, fully surveyed portion of the Galactic plane for four of the most common types of masers found in the vicinity of star formation regions. Comparison of the occurrence of the four maser types with far-infrared dust temperatures shows that sources exhibiting excited-state OH maser emission are warmer than sources showing any of the other three maser types. We further find that sources exhibiting both 6.7-GHz and 12.2-GHz methanol masers are warmer than sources exhibiting just 6.7-GHz methanol maser emission. These findings are consistent with previously made suggestions that both OH and 12.2-GHz methanol masers generally trace a later stage of star formation compared to other common maser types

New insights into the character of austenite-ferrite boundaries in an additively manufactured duplex stainless steel

The crystallography and chemistry of interfaces between austenite and ferrite in duplex steels control many important materials properties but remain poorly understood. In this study, we experimentally show that in an additively manufactured and heat treated duplex stainless steel, the majority of austenite-ferrite interfaces terminate on {111}A/{110}F planes, and this behaviour is more pronounced for rational interfaces with the Kurdjomov-Sachs orientation relationship. Interface segregation was found to be controlled by not only the interface crystallography but also the bonding properties of solute atoms. Solute elements showed higher interfacial excess at irrational interfaces. Furthermore, a heterogeneous distribution of selected solute elements in austenite-ferrite interfaces planes was observed. Our findings reinforce the importance and, in fact, necessity to consider five independent crystallographic parameters and chemical architecture of interphase boundaries for advanced control of mechanical and other critical properties in duplex materials

Genome-wide association for major depression through age at onset stratification

BACKGROUND: Major depressive disorder (MDD) is a disabling mood disorder, and despite a known heritable component, a large meta-analysis of genome-wide association studies revealed no replicable genetic risk variants. Given prior evidence of heterogeneity by age at onset in MDD, we tested whether genome-wide significant risk variants for MDD could be identified in cases subdivided by age at onset. METHODS: Discovery case-control genome-wide association studies were performed where cases were stratified using increasing/decreasing age-at-onset cutoffs; significant single nucleotide polymorphisms were tested in nine independent replication samples, giving a total sample of 22,158 cases and 133,749 control subjects for subsetting. Polygenic score analysis was used to examine whether differences in shared genetic risk exists between earlier and adult-onset MDD with commonly comorbid disorders of schizophrenia, bipolar disorder, Alzheimer’s disease, and coronary artery disease. RESULTS: We identified one replicated genome-wide significant locus associated with adult-onset (>27 years) MDD (rs7647854, odds ratio: 1.16, 95% confidence interval: 1.11–1.21, p = 5.2 × 10-11). Using polygenic score analyses, we show that earlier-onset MDD is genetically more similar to schizophrenia and bipolar disorder than adult-onset MDD. CONCLUSIONS: We demonstrate that using additional phenotype data previously collected by genetic studies to tackle phenotypic heterogeneity in MDD can successfully lead to the discovery of genetic risk factor despite reduced sample size. Furthermore, our results suggest that the genetic susceptibility to MDD differs between adult- and earlier-onset MDD, with earlier-onset cases having a greater genetic overlap with schizophrenia and bipolar disorder

Discovery of six new class II methanol maser transitions, including the unambiguous detection of three torsionally excited lines toward G 358.931-0.030

We present the unambiguous discovery of six new class II methanol maser transitions, three of which are torsionally excited (vt = 1). The newly discovered 6.18 GHz 17−2 → 18−3 E (vt = 1), 7.68 GHz 124 → 133 A− (vt = 0), 7.83 GHz 124 → 133 A+ (vt = 0), 20.9 GHz 101 → 112 A+ (vt = 1), 44.9 GHz 20 → 31 E (vt = 1), and 45.8 GHz 93 → 102 E (vt = 0) methanol masers were detected toward G 358.931-0.030, where the known 6.68 GHz maser has recently been reported to be undergoing a period flaring. The detection of the vt = 1 torsionally excited lines corroborates one of the missing puzzle pieces in class II maser pumping, but the intensity of the detected emission provides an additional challenge, especially in the case of the very highly excited 6.18 GHz line. Together with the newly detected vt = 0 lines, these observations provide significant new information that can be utilized to improve class II methanol maser modeling. We additionally present detections of 6.68, 19.9, 23.1, and 37.7 GHz class II masers, as well as 36.2 and 44.1 GHz class I methanol masers, and provide upper limits for the 38.3 and 38.5 GHz class II lines. Near simultaneous Australia Telescope Compact Array observations confirm that all 10 of the class II methanol maser detections are co-spatial to ∼0.2 arcsec, which is within the uncertainty of the observations. We find significant levels of linearly polarized emission in the 6.18, 6.67, 7.68, 7.83, 20.9, 37.7, 44.9, and 45.8 GHz transitions, and low levels of circular polarization in the 6.68, 37.7, and 45.8 GHz transitions

Tinjauan Hukum Islam Terhadap implementasi kafa'ah nasab dalam pernikahan para Pedagang etnis Arab di Wisata Ampel Kota Surabaya

Skripsi yang berjudul Tinjauan Hukum Islam Terhadap Implementasi kafa’ah nasab dalam pernikahan para pedagang etnis Arab di Wisata Ampel Kota Surabaya merupakan hasil penelitian lapangan yang bertujuan untuk menjawab beberapa pertanyaan berikut: pertama, Bagaimana Implementasi Kafa’ah Nasab dalam Pernikahan Para Pedagang Etnis Arab di Wisata Ampel Kota Surabaya? Kedua, Bagaimana Tinjauan Hukum Islam Terhadap Implementasi Kafa’ah Nasab dalam Pernikahan Para Pedagang Etnis Arab di Wisata Ampel Kota Surabaya? Data penelitian dihimpun melalui wawancara dan dokumentasi kemudian dianalisis dengan menggunakan teknik deskriptif analisis dengan pola pikir deduktif. Hasil penelitian ini menyimpulkan bahwa para pedagang etnis Arab di Wisata Ampel Kota Surabaya yang terbagi menjadi dua golongan atau fame : pertama golongan Alawiyin dan kedua golongan Qabili, kedua golongan tersebut sangat menekankan kafa’ah nasab dalam pernikahan, golongan Alawiyin mempertahankan kafa’ah nasab dalam pernikahan karena meyakini hal tersebut sebagai doktrin sehingga percaya bahwa menjaga garis keturunan Rasulullah merupakan sebuah keniscayaan, adapun golongan Qabili mempertahankan kafa’ah nasab memiliki alasan yang sama dengan golongan atau fame Alawiyin yaitu mempertahankan garis keturunan yang membedakan adalah fame / golongan Qabili tidak meyakini hal tersebut sebagai sebuah doktrin namun hanya sebatas menjaga budaya Patrilineal yaitu suatu adat masyarakat yang mengatur alur keturunan berasal dari pihak ayah. Dalam hukum Islam Implementasi kafa’ah nasab dalam pernikahan telah dijelaskan secara lugas oleh para ulama meskipun diantara mereka terjadi perbedaan pendapat karena secara eksplisit tidak disebutkan dalam al-Quran dan as-Sunnah. Pada dasarnya Islam mengajarkan bahwa manusia itu sama, antara yang kaya dan yang miskin, orang Arab dan orang ajam, memilih pasangan dalam Islam menganjurkan untuk memilih dan mengutamakan ketakwaan dan akhlak bagi calon pasangannya karena orang yang paling mulia disisi Allah adalah orang yang paling bertakwa Akan tetapi, dalam rangka membentuk keluarga yang sakinah, mawwadah, dan rahmah ketentuan kafa’ah nasab juga diperlukan dan dihukumi sebagai sesuatu yang mubah/ diperbolehkan dalam agama. Disarankan bagi para orangtua dan para pemuda-pemudi yang akan melaksanakan pernikahan, hendaknya mempertimbangkan agama sebagai tolak ukur utama adapun menjadikan nasab sebagai tolak ukur maka hal tersebut merupakan tidak tercela dalam agama karena dihukumi sebagai sesuatu yang mubah/ diperbolehkan dalam agama kemudian untuk golongan atau fame Alawiyin semoga lebih bijak lagi dalam menyikapi kafa’ah nasab sehingga ada keterbukaan dan tidak ada lagi sekat pemisah antara manusia satu dengan manusia yang lain

Detection of 36GHz Class I methanol maser emission toward NGC 4945

We have searched for emission from the 36.2 GHz (4-1 → 30E) methanol transition toward NGC 4945, using the Australia Telescope Compact Array. 36.2 GHz methanol emission was detected offset southeast from the Galactic nucleus. The methanol emission is narrow, with a line width −1 and a luminosity five orders of magnitude higher than Galactic class I masers from the same transition. These characteristics combined the with physical separation from the strong central thermal emission suggests that the methanol emission is a maser. This emission is a factor of ∼90 more luminous than the widespread emission detected from the Milky Way central molecular zone. This is the fourth detection of extragalactic class I emission and the third detection of extragalactic 36.2 GHz maser emission. These extragalactic class I methanol masers do not appear to be simply highly luminous variants of Galactic class I emission and instead appear to trace large-scale regions of low-velocity shocks in molecular gas, which may precede, or be associated with, the early stages of large-scale star formation