3,552 research outputs found

    Heat Transfer for Laminar Flow Through Parallel Porous Disks

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    The problem of temperature distribution and heat transfer for laminar flow through two parallel porous disks, has been investigated when the flow is entirely due t injection or suction at the two disks. Viscous dissipation terms have been included in the energy equation and the uniform injection/suction velocities at the two disks, are assumed to be small. The boundaries are maintained at constant temperature. The variation of temperature and Nusselt numbers at the two disks, is shown graphically, for various of the injection/suction velocities

    Dephosphorization of Liquid Ferromanganese

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    Ferromanganese is used as deoxidizing and alloying agent in steelmaking. In order to produce high quality steel, it is desirable to have phosphorus contents in the ferro-manganese less than 0.25%. However, the ferromanganese alloys produced in India continue to have high (>0.4%) phosphorus levels.There are no established methods exis-ting for lowering the phoshorus levels in ferromanganese

    Selective removal of phosphorus from high carbon ferromanganese - an improved process

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    The presence of phosphorus is known to deteriorate the mechanical properties of cast steel and other metallic products. Ferromanganese, used as the last additive during steel making, is one of the main sources of phosphorus contamination. Therefore phosphorus has to be removed from the ferromanganese before it is used as a deoxidizing and alloying agent. The bulk of high carbon ferromanganese produced in India continues to have more than 0.35% phosphorus since they are produced by carbothermic reduction process. A systematic study by NML showed that it was possible to remove phosphorus from high carbon liquid ferromanganese successfully from 0.56% to 0.18% using BaCO3 based fluxes at the rate of 16-wt% of the ferromanganese charged. However, the Mn loss varied in the range of 2-5%. The objective of the present study was to optimize the flux consumption as well as minimize the Mn loss with effective dephosphorization by using BaO based calcined pellets instead of BaCO3 based powders. It is easier to handle pellets under plant conditions and eliminate the loss of flux as a dust, which occurs when powder is added. These pellets can be forced towards the bottom of the melt for better efficiency. Another advantage of using pellets is that it utilizes manganese ore fines, which is a waste material in the ferromanganese industry. The results have shown that the addition of moderate amount of MnO into the pellets reduces the Mn loss while it helps dephosphorization. The results achieved indicate that it is possible to achieve more than 60% phosphorus removal using flux addition at 5% by weight of the ferromanganese charged

    Fisheries geographical information system for Greater Mumbai region in Maharashtra, India

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    Geographical information system (GIS) is an invaluable decision support tool, designed to address spatially related problems for management of natural resources. The power of GIS lies in its ability to visualise and relate various types of geo-referenced spatial and non-spatial data allowing users to analyse them. In India, use of GIS in fisheries management is yet to find its rightful place. An effort has been made in the present study to design and organise a fisheries spatial information system for Greater Mumbai region in Maharashtra to serve as a macro-level database for the planners and administrators, which can be used for querying, analysing and displaying datasets in the form of graphs and summarised tabular data for all the fisheries infrastructural facilities. This GIS will be of immense help to planners, managers and administrators in quick storing, retrieving and updating the required information for management of fisheries in Greater Mumbai region

    Post-flight Analysis and Design Improvement in Command Guidance System for a Short-range Surface-to-air Missile System

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    A short-range missile with command-to line-of-sight and three-beam guidance has been considered in this paper. The earlier command guidance system (CGS) design shows unacceptablyhigh-low-frequency weave-mode oscillations, leading to high latax and body rate oscillations, even for benign, low-speed non-manoeuvring target engagements. For successful targetengagements with the three-beam guidance, missile is to be handed over from wide-to-medium receiver beam, and finally, from medium-to-the most accurate narrow receiver beam, depending on the angular error wrt line-of-sight as early as possible. Due to large amplitude oscillation in the earlier CGS design, the handing over of the missile to narrow receiver beam, and in many cases, to the medium receiver beam, itself could not take place, leading to failure of guidance. In this paper, the cause for this undesirable high magnitude weave-mode oscillation has been analysed in detail. After establishing this, saturation aspects of the earlier CGS design; a simple implementable CGS re-design was carried out to reduce this saturation aspect drastically for preserving almost full-phase advance effects of the linear new analogue compensators designed to give the required stability margins of guidance loop

    Relevance of progesterone receptor immunohistochemical staining to Oncotype DX recurrence score

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    AbstractObjective/BackgroundProgesterone-receptor negativity (PR−) is predictive of adverse outcomes in estrogen receptor-positive (ER+) breast cancer. The Oncotype DX assay provides risk stratification for hormone receptor-positive (HR+) invasive breast cancer; however, the association of PR status and Oncotype DX recurrence scores (RSs) is less clear.MethodsWe designed an analysis to determine whether a significant difference exists in the RS for ER+/PR− tumors when compared with ER+/PR+ breast cancer. Three hundred and fifty patients with HR+ invasive breast cancer who underwent Oncotype DX testing at our institution from December 2006 to October 2013 were included. We also examined the concordance in the HR status reported by immunohistochemical (IHC) and reverse transcriptase-polymerase chain reaction (RT-PCR) analyses. The data were analyzed by analysis of variance, F test, t test, and chi-square tests. Multivariate linear regression was used to determine significant predictors of Oncotype DX RS.ResultsA total of 301 patients had ER+/PR+ tumors and 47 patients had ER+/PR− tumors by IHC. PR− tumors had a significantly higher RS than PR+ tumors (24.7±8.53 vs. 17.3±7.38; p<.001), predicting a greater 10-year risk of distant recurrence. Multivariate linear regression showed PR status and tumor grade to be significant predictors of Oncotype DX RS (p<.0001). A total of 284 patients had HR status reported by Oncotype DX assay. Concordance between IHC and RT-PCR was 99.3% for ER and 88.7% for PR.ConclusionOur study shows that ER+/PR− breast cancer tumors are associated with a significantly higher Oncotype DX scores; this interprets into a higher risk of recurrence. Our data also show that the concordance between IHC and RT-PCR was 99.3% for ER and lower at 88.7% for PR

    Differential nucleosome occupancy modulates alternative splicing in Arabidopsis thaliana

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    • Alternative splicing (AS) is a major gene regulatory mechanism in plants. Recent evidence supports co-transcriptional splicing in plants, hence the chromatin state can impact AS. However, how dynamic changes in the chromatin state such as nucleosome occupancy influence the cold-induced AS remains poorly understood. • Here, we generated transcriptome (RNA-Seq) and nucleosome positioning (MNase-Seq) data for Arabidopsis thaliana to understand how nucleosome positioning modulates cold-induced AS. • Our results show that characteristic nucleosome occupancy levels are strongly associated with the type and abundance of various AS events under normal and cold temperature conditions in Arabidopsis. Intriguingly, exitrons, alternatively spliced internal regions of protein-coding exons, exhibit distinctive nucleosome positioning pattern compared to other alternatively spliced regions. Likewise, nucleosome patterns differ between exitrons and retained introns pointing to their distinct regulation. • Collectively, our data show that characteristic changes in nucleosome positioning modulate AS in plants in response to cold
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