934 research outputs found
A Process Capability Analysis Method Using Adjusted Modified Sample Entropy
Citation: Koppel, S., & Chang, S. I. (2016). A Process Capability Analysis Method Using Adjusted Modified Sample Entropy. Procedia Manufacturing, 5, 122-131. doi:10.1016/j.promfg.2016.08.012The evolution of sensors and data storage possibilities has created possibilities for more precise data collection in processes. However, process capability analysis has become more difficult. Traditional methods, such as process capability ratios, cannot handle large volumes of process data over time because these methods assume normal process distribution that is not changing. Entropy methods have been proposed for process capability studies because entropy is not dependent on distribution and can therefore provide accurate readings in changing distribution environments. The goal of this paper is to explore the use of entropy-based methods, specifically modified Sample Entropy to identify process variations over time. A study based on simulated data sets showed that the proposed method provides process capability information. © 2016 The Author
Computer program developed for flowsheet calculations and process data reduction
Computer program PACER-65, is used for flowsheet calculations and easily adapted to process data reduction. Each unit, vessel, meter, and processing operation in the overall flowsheet is represented by a separate subroutine, which the program calls in the order required to complete an overall flowsheet calculation
Unsteady skin friction experimentation in a large diameter pipe
Experimental data for the validation of theoretical models of unsteady skin friction are limited and are available only for a few low Reynolds number flow cases. There is a strong need for detailed measurements in flows at high Reynolds numbers. In addition, there is a need for a wider range of well-controlled acceleration/deceleration rates and detailed visualization of flow structure and profiles. To address these needs, a large-scale pipeline apparatus at Deltares, Delft, The Netherlands, has been used for unsteady skin friction experiments including acceleration, deceleration and acoustic resonance tests. The apparatus consists of a constant head tank, a horizontal 200 mm diameter pipe of changeable length (44 to 49 metres) and a control valve at the downstream end. In addition to standard instrumentation, two distinctive instruments have been used: hot-film wall shear stress sensors ("direct" measurement of wall shear stress) and a PIV set-up for measurement of unsteady flow profiles. This paper describes the test rig, the instrumentation layout and the test programme. Finally, some initial test results are presented and discussed
Help in Time: An Evaluation of Philadelphia\u27s Community-Based Homelessness Prevention Program
This report provides an evaluation of Philadelphia\u27s neighborhood-based homelessness prevention initiative. Results indicate that nearly all households served do not become homeless. But it is unclear if households would have become homeless had they not been served. Recommendations are made for targeting prevention interventions to families requesting shelter
Differential cargo mobilisation within Weibel-Palade bodies after transient fusion with the plasma membrane.
Inflammatory chemokines can be selectively released from Weibel-Palade bodies (WPBs) during kiss-and-run exocytosis. Such selectivity may arise from molecular size filtering by the fusion pore, however differential intra-WPB cargo re-mobilisation following fusion-induced structural changes within the WPB may also contribute to this process. To determine whether WPB cargo molecules are differentially re-mobilised, we applied FRAP to residual post-fusion WPB structures formed after transient exocytosis in which some or all of the fluorescent cargo was retained. Transient fusion resulted in WPB collapse from a rod to a spheroid shape accompanied by substantial swelling (>2 times by surface area) and membrane mixing between the WPB and plasma membranes. Post-fusion WPBs supported cumulative WPB exocytosis. To quantify diffusion inside rounded organelles we developed a method of FRAP analysis based on image moments. FRAP analysis showed that von Willebrand factor-EGFP (VWF-EGFP) and the VWF-propolypeptide-EGFP (Pro-EGFP) were immobile in post-fusion WPBs. Because Eotaxin-3-EGFP and ssEGFP (small soluble cargo proteins) were largely depleted from post-fusion WPBs, we studied these molecules in cells preincubated in the weak base NH4Cl which caused WPB alkalinisation and rounding similar to that produced by plasma membrane fusion. In these cells we found a dramatic increase in mobilities of Eotaxin-3-EGFP and ssEGFP that exceeded the resolution of our method (∼ 2.4 µm2/s mean). In contrast, the membrane mobilities of EGFP-CD63 and EGFP-Rab27A in post-fusion WPBs were unchanged, while P-selectin-EGFP acquired mobility. Our data suggest that selective re-mobilisation of chemokines during transient fusion contributes to selective chemokine secretion during transient WPB exocytosis. Selective secretion provides a mechanism to regulate intravascular inflammatory processes with reduced risk of thrombosis
The benefits of interprofessional education 10 years on.
Interprofessional education (IPE) was first conceived in 1973 by a World Health Organization (WHO) expert group in Geneva. WHO member states were then charged with implementing medical education IPE pilot projects and from then to today there has a been a rapid proliferation in the number of publications on the subject. IPE has generated research into its use, conferences specific to IPE, organisations dedicated to it and policy championing it. The authors question whether there has been any major shift in the silos in which different professions might be working. The authors published an article on the benefits of IPE ( Illingworth and Chelvanayagam, 2007 ). Ten years have now passed and many changes have been implemented and experienced in health and social care and therefore a review of the literature is required. Also, it is 7 years since the publication of WHO's report outlining the role of IPE in the preparation of health professionals ( WHO, 2010 ) and, increasingly, UK Government policy champions collaborative and integrated working. The conclusions from the 2007 article acknowledged the development of IPE; however, it highlighted the need for empirical evidence to demonstrate the effectiveness of IPE in service user and carer outcomes. This article will explore whether IPE has achieved the benefits discussed in the previous article and what developments have occurred since it was published
Experimental investigation on rapid filling of a large-scale pipeline
This study presents results from detailed experiments of the two-phase pressurized flow behavior during the rapid filling of a large-scale pipeline. The physical scale of this experiment is close to the practical situation in many industrial plants. Pressure transducers, water level meters, thermometers, void fraction meters and flow meters were used to measure the two-phase unsteady flow dynamics. The main focus is on the water-air interface evolution during filling and the overall behavior of the lengthening water column. It is observed that the leading liquid front does not entirely fill the pipe cross section; flow stratification and mixing occurs. Although flow regime transition is a rather complex phenomenon, certain features of the observed transition pattern are explained qualitatively and quantitatively. The water flow during the entire filling behaves as a rigid column as the open empty pipe in front of the water column provides sufficient room for the water column to occupy without invoking air compressibility effects. As a preliminary evaluation of how these large-scale experiments can feed into improving mathematical modeling of rapid pipe filling, a comparison with a typical one-dimensional rigid-column model is made
Experimental study of filling and emptying of a large-scale pipeline
The ¿lling with liquid of an initially empty pipeline and its counterpart, the draining of an initially liquid-¿lled pipeline, are of great interest due to the many practical applications. Several potential problems may occur, of which water-hammer and slug impact are the most important. To investigate the ¿lling and emptying processes, di¿erent mathematical models have been proposed, in which a common assumption is that the water column evolves with unchanged front and/or tail. This is a reasonable assumption for small-scale systems, particularly in cases with relatively high upstream pressure head and low downstream resistance. However, it is not clear whether this assumption is applicable to large-scale systems. This issue is of high importance for the development of air pockets and gravity currents in pipelines during ¿lling and draining processes. This study presents the experimental results of the ¿ow behaviour during the rapid ¿lling and emptying of a large-scale pipeline. The experimental apparatus was designed and built at Deltares, Delft, The Netherlands, as part of the EC Hydralab III project. Di¿erent from other laboratory studies, the scale of this experiment is close to the practical situation in many industrial plants. The test rig includes a variety of components (e.g. tanks, ¿ow meters, valves, pipes of di¿erent materials) and the operation procedure is rather complex. The ¿ow behaviour is measured by various instruments and hence a thorough hydrodynamic analysis is possible. All these features make the current study particularly useful as a test case for real ¿lling and draining situations. In the ¿lling of an initially empty pipeline, the focus was on the overall behaviour of the lengthening water column and the water-air interface evolution. In the emptying of an initially water-¿lled pipeline, together with the hydrodynamics of the shortening water column, the shape and behaviour of the water tail (air-water interface) was investigated. Thirteen di¿erent combinations of initial upstream driving air pressure and downstream valve resistance were tested. The in¿uence of these two factors on the out¿ow rate is clari¿ed. It was con¿rmed that both the in¿ow front in ¿lling and the out¿ow tail in emptying do not entirely ¿ll the pipe cross section. Shape changes occur at both the water-air and air-water interfaces. Although the ¿ow regime transition is a rather complex phenomenon, certain features of the transition pattern are observed and explained qualitatively and quantitatively
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