Queen's University Belfast

About: Queen's University Belfast is a education organization based out in Belfast, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 25457 authors who have published 55463 publications receiving 1751346 citations. The organization is also known as: Queen's College, Belfast & Queen's College.

The VLT-FLAMES Tarantula Survey: I. Introduction and observational overview⋆

Abstract: The VLT-FLAMES Tarantula Survey (VFTS) is an ESO Large Programme that has obtained multi-epoch optical spectroscopy of over 800 massive stars in the 30 Doradus region of the Large Magellanic Cloud (LMC). Here we introduce our scientific motivations and give an overview of the survey targets, including optical and near-infrared photometry and comprehensive details of the data reduction. One of the principal objectives was to detect massive binary systems via variations in their radial velocities, thus shaping the multi-epoch observing strategy. Spectral classifications are given for the massive emission-line stars observed by the survey, including the discovery of a new Wolf-Rayet star (VFTS 682, classified as WN5h), 2' to the northeast of R136. To illustrate the diversity of objects encompassed by the survey, we investigate the spectral properties of sixteen targets identified by Gruendl & Chu from Spitzer photometry as candidate young stellar objects or stars with notable mid-infrared excesses. Detailed spectral classification and quantitative analysis of the O- and B-type stars in the VFTS sample, paying particular attention to the effects of rotational mixing and binarity, will be presented in a series of future articles to address fundamental questions in both stellar and cluster evolution.

Buyer–supplier relationships: derived value over two decades

Abstract: This paper reviews studies of buyer–supplier relationships published in four prominent U.S.-based academic journals between 1986 and 2005. Our review revealed that the focus of academic researchers on types of value being extracted from buyer–supplier relationships changed between 1986 and 2005, as did their interest in the buyer mechanisms implemented to create value in these relationships. Although emphasis has changed over time, we found that scholars have primarily investigated four types of value derived from buyer–suppler relationships: operational performance improvements, integration-based improvements, supplier capability-based improvements and financial performance outcomes. The review also noted that researchers considered more buyer–supplier mutual efforts since 1996 than the earlier decade, but the number of studies investigating buyer practices has declined as a percentage of total publications. We conclude with a discussion of the review's implications for future research and practice.

Communicating chemical congregation: a molecular AND logic gate with three chemical inputs as a "lab-on-a-molecule" prototype.

Abstract: We demonstrate the first three-input molecular AND logic gate based on three chemical inputs as a direct way of detecting congregations of chemical species. The AND gate operates in water and responds to Na+, H+, and Zn2+ inputs with an enhanced fluorescence signal when pre-set concentration thresholds are exceeded. Future “lab-on-a-molecule” devices could have application in medicine for rapid disease screening.