Thermal histories of CB meteorites: Constraints from compositions and microstructures of sulfides

CBs are metal-rich carbonaceous chondrites, and are subdivided into type CBa and CBb, which are primarily distinguished by the size of particles. Although CBs are classified as chondrites, the high abundance of metal (\u3e40%) make them a distinct group of meteorites. The origin of CBs is highly debated, but these meteorites are thought to have formed in an impact-generated vapor plume 4.563 Ga ago [Amelin et al., 2005; Krot et al., 2005], rather than in the solar nebula. This study focuses on textures and compositions of homogeneous and exsolved sulfides in metal grains in CB meteorites to constrain secondary thermal histories. We use SEM, EPMA, FIB, and TEM techniques to examine metal and sulfides, and quantify modal abundances of metal particles and sulfide inclusions using high-resolution BSE images with ImageJ software. CB metal (Fe,Ni) particles contain different types of sulfide inclusions, which we categorize as: homogeneous low-Cr sulfide inclusions composed of MSS1, exsolved sulfide inclusions of MSS1 with high-Cr daubreelite, sulfide inclusions with Fe,Ni metal blebs, and arcuate sulfides. Some particles also contain Fe-Ni-S eutectic textures composed of a mixture of MSS1 and Fe,Ni metal. The four CB meteorites analyzed (CBa Gujba, CBa Weatherford, CBb HH 237, and CBb QUE 94411) all contain these sulfides within metal grains. Sulfide inclusions possibly formed as a result of precipitation of excess S from solid metal at low temperatures. The CB parent body was likely affected by late impacts, causing heterogeneous heating of surface material. This work provides evidence of heterogeneous reheating by impacts. Examination of exsolved sulfides shows that they record maximum reheating temperatures of \u3c\u3c600°C, and Fe-Ni-S eutectic textures show reheating temperatures of \u3e950°C. Observations of fine-grained textures and small size of particles indicates reheating must have been followed by very rapid cooling. Plastic deformation is also observed in some metal grains and lamellae of exsolved sulfide inclusions, indicating deformation post-dates formation of inclusions. Our study shows that CBa and CBb meteorites not only formed in a similar environment, but they also experienced similar secondary processing

Quantifying the desired degree of supply chain flexibility

The dynamic nature of today\u27s market drives the need for flexibility in supply chains. The ever-growing need for and importance of flexibility in supply chains has motivated researchers to develop frameworks to achieve supply chain flexibility. Much of the research on supply chain flexibility focuses on drivers of the need for flexibility and classification of supply chain flexibility. Existing frameworks for determining the desired degree of flexibility in supply chains give an overview methodology; however, a comprehensive framework is absent. This research proposes a comprehensive framework to quantify the desired degree of flexibility in supply chains and accordingly determine its associated configuration --Abstract, page iii

Sociocognition Issues Affecting the Working Relationship between the Deaf Professional and the Interpreter

The focus of this paper is to review the literature on socio-cognition issues for deaf graduate students and professionals working with interpreters in order to assess its usefulness in developing key conditions under which deaf graduate student/professional- interpreterworkingrelationshipsmightbeimplementedmoreeffectively. Theories on cognitive dissonance and stereotyping will be examined in relation to their possible implications in the working relationship, and included in this review if they related to the development and maintenance of an ongoing working relationship between the deaf professional and the interpreter. The concept, cognitive dissonance, will be introduced in this discussion and examined for its relevance to the inconsistency between attitudes and behaviors that emerge in the deaf professional or the interpreter as they enter the working relationship. This paper may provide insights into the mechanisms of developing an ongoing working relationship which may guide development of advanced or specialized interpreter training programs

A Parallelized Approach for Colorizing Grayscale Images

International audienceImage processing plays an integral role in the field of computer science and is incorporated in numerous applications such as remote sensing, medical imaging, image restoration, and machine vision. One of the challenging tasks in image processing is colorizing grayscale images. Restoring color in grayscale images aids in enhancing the visual cognition of image data such medical images, surveillance images, and scientific illustrations. Compared to the relatively simpler process of converting color images to grayscale, the process of colorizing grayscale images is much more complex, is not based on any one particular method, and is significantly dependent on the human perception of color. Additionally, such a colorizing process is generally computation-intensive and tedious. Hence, a parallelized high-performance approach based on many-core programming and the CUDA platform is presented in this paper for colorizing grayscale images. The proposed approach has been developed with the objective of incorporation in huge image datasets (such as those obtained from satellites) and video frame sequences