Large ESR forging ingots and their quality in production

ESR is known as an alternative step on the continuous improvement in single ingot production for heavyforgings. In the recent past a new state of the art ESR remelting system was installed with the possibility toproduce ingots in diameter from 1000mm for 45tons till 2000mm for 145tons. Consumable electrodes fromtraditional fabrication processes which consist of melting with electrical arc furnace, refining, degassingof the steel and bottom pouring will be used to produce one single heavy ingot with best cleanness withthe help of electrode exchange technique. This paper tells about the furnace characteristics and the efforts tobe made to ensure high quality level in material and furnace preparation as well as save automatic productionperformances during remelting and electrode exchange. Finally the results of ingots characterized by anelevated level of chemical homogeneity and internal quality such as to ensure the absence of defectgreater than 0.5mm AVG during the final inspection of the forged part from the ESR production will bepresented. The ESR process serves for the reproducible quality in heavy ingot making and tightens the limits inspecifications together with high material yield

What is the Role of NLP in Text Retrieval?

This paper addresses the value of linguistically-motivated indexing (LMI) for document and text retrieval. After reviewing the basic concepts involved and the assumptions on which LMI is based, namely that complex index descriptions and terms are necessary, I consider past and recent research on LMI, and specifically on automated LMI via NLP. Experiments in the first phase of research, to the late eighties, did not demonstrate value in LMI, but were very limited; but the much larger tests of the Nineties, with full text, have not done so either. My conclusion is that LMI is not needed for effective retrieval, but has other important roles within information-selection systems. The rapid growth of full text databases, together with developments in natural language processing (NLP) technology, has prompted those engaged with NLP to suggest that it could be usefully applied to text retrieval, primarily for indexing purposes but perhaps also for more or less related tasks such as document ‘abstracting ’ or extracting; it could be applied at shallow text as well as at deep content levels, and for user display or for database creation. Retrieval itself has various modes, including filtering or routing as well as one-off searching

Autonomous Role of 3′-Terminal CCCA in Directing Transcription of RNAs by Qβ Replicase

We have studied transcription in vitro by Qβ replicase to deduce the minimal features needed for efficient end-to-end copying of an RNA template. Our studies have used templates ca. 30 nucleotides long that are expected to be free of secondary structure, permitting unambiguous analysis of the role of template sequence in directing transcription. A 3′-terminal CCCA (3′-CCCA) directs transcriptional initiation to opposite the underlined C; the amount of transcription is comparable between RNAs possessing upstream (CCA)(n) tracts, A-rich sequences, or a highly folded domain and is also comparable in single-round transcription assays to transcription of two amplifiable RNAs. Predominant initiation occurs within the 3′-CCCA initiation box when a wide variety of sequences is present immediately upstream, but CCA or a closely similar sequence in that position results in significant internal initiation. Removal of the 3′-A from the 3′-CCCA results in 5- to 10-fold-lower transcription, emphasizing the importance of the nontemplated addition of 3′-A by Qβ replicase during termination. In considering whether 3′-CCCA could provide sufficient specificity for viral transcription, and consequently amplification, in vivo, we note that tRNA(His) is the only stable Escherichia coli RNA with 3′-CCCA. In vitro-generated transcripts corresponding to tRNA(His) served as poor templates for Qβ replicase; this was shown to be due to the inaccessibility of the partially base-paired CCCA. These studies demonstrate that 3′-CCCA plays a major role in the control of transcription by Qβ replicase and that the abundant RNAs present in the host cell should not be efficient templates