WorldWideScience

Sample records for human ipsc-derived multistage

  1. Functional Characterization of IPSC-Derived Brain Cells as a Model for X-Linked Adrenoleukodystrophy.

    Science.gov (United States)

    Baarine, Mauhamad; Khan, Mushfiquddin; Singh, Avtar; Singh, Inderjit

    2015-01-01

    X-ALD is an inherited neurodegenerative disorder where mutations in the ABCD1 gene result in clinically diverse phenotypes: the fatal disorder of cerebral childhood ALD (cALD) or a milder disorder of adrenomyeloneuropathy (AMN). The various models used to study the pathobiology of X-ALD disease lack the appropriate presentation for different phenotypes of cALD vs AMN. This study demonstrates that induced pluripotent stem cells (IPSC) derived brain cells astrocytes (Ast), neurons and oligodendrocytes (OLs) express morphological and functional activities of the respective brain cell types. The excessive accumulation of saturated VLCFA, a "hallmark" of X-ALD, was observed in both AMN OLs and cALD OLs with higher levels observed in cALD OLs than AMN OLs. The levels of ELOVL1 (ELOVL Fatty Acid Elongase 1) mRNA parallel the VLCFA load in AMN and cALD OLs. Furthermore, cALD Ast expressed higher levels of proinflammatory cytokines than AMN Ast and control Ast with or without stimulation with lipopolysaccharide. These results document that IPSC-derived Ast and OLs from cALD and AMN fibroblasts mimic the respective biochemical disease phenotypes and thus provide an ideal platform to investigate the mechanism of VLCFA load in cALD OLs and VLCFA-induced inflammatory disease mechanisms of cALD Ast and thus for testing of new therapeutics for AMN and cALD disease of X-ALD.

  2. Human iPSC Derived GABA Ergic Precursor Cell Therapy for Chronic Epilepsy

    Science.gov (United States)

    2016-10-01

    Shetty, Ph.D. CONTRACTING ORGANIZATION: Texas A&M University System College Station, TX 77845 REPORT DATE: October 2016 TYPE OF REPORT: Annual...DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE October 2016 2. REPORT TYPE Annual 3. DATES COVERED 30Sep2015-29Sep2016 4. TITLE AND...ameliorate learning and memory impairments and depression (Specific Aim 2, SA2). Studies performed so far have focused on rigorously addressing the

  3. Modeling Humans as Reinforcement Learners: How to Predict Human Behavior in Multi-Stage Games

    Science.gov (United States)

    Lee, Ritchie; Wolpert, David H.; Backhaus, Scott; Bent, Russell; Bono, James; Tracey, Brendan

    2011-01-01

    This paper introduces a novel framework for modeling interacting humans in a multi-stage game environment by combining concepts from game theory and reinforcement learning. The proposed model has the following desirable characteristics: (1) Bounded rational players, (2) strategic (i.e., players account for one anothers reward functions), and (3) is computationally feasible even on moderately large real-world systems. To do this we extend level-K reasoning to policy space to, for the first time, be able to handle multiple time steps. This allows us to decompose the problem into a series of smaller ones where we can apply standard reinforcement learning algorithms. We investigate these ideas in a cyber-battle scenario over a smart power grid and discuss the relationship between the behavior predicted by our model and what one might expect of real human defenders and attackers.

  4. Variable behavior of iPSCs derived from CML patients for response to TKI and hematopoietic differentiation.

    Directory of Open Access Journals (Sweden)

    Aurélie Bedel

    Full Text Available Chronic myeloid leukemia disease (CML found effective therapy by treating patients with tyrosine kinase inhibitors (TKI, which suppress the BCR-ABL1 oncogene activity. However, the majority of patients achieving remission with TKI still have molecular evidences of disease persistence. Various mechanisms have been proposed to explain the disease persistence and recurrence. One of the hypotheses is that the primitive leukemic stem cells (LSCs can survive in the presence of TKI. Understanding the mechanisms leading to TKI resistance of the LSCs in CML is a critical issue but is limited by availability of cells from patients. We generated induced pluripotent stem cells (iPSCs derived from CD34⁺ blood cells isolated from CML patients (CML-iPSCs as a model for studying LSCs survival in the presence of TKI and the mechanisms supporting TKI resistance. Interestingly, CML-iPSCs resisted to TKI treatment and their survival did not depend on BCR-ABL1, as for primitive LSCs. Induction of hematopoietic differentiation of CML-iPSC clones was reduced compared to normal clones. Hematopoietic progenitors obtained from iPSCs partially recovered TKI sensitivity. Notably, different CML-iPSCs obtained from the same CML patients were heterogeneous, in terms of BCR-ABL1 level and proliferation. Thus, several clones of CML-iPSCs are a powerful model to decipher all the mechanisms leading to LSC survival following TKI therapy and are a promising tool for testing new therapeutic agents.

  5. In vivo liver regeneration potential of human induced pluripotent stem cells from diverse origins.

    Science.gov (United States)

    Liu, Hua; Kim, Yonghak; Sharkis, Saul; Marchionni, Luigi; Jang, Yoon-Young

    2011-05-11

    Human induced pluripotent stem cells (iPSCs) are a potential source of hepatocytes for liver transplantation to treat end-stage liver disease. In vitro differentiation of human iPSCs into hepatic cells has been achieved using a multistage differentiation protocol, but whether these cells are functional and capable of engrafting and regenerating diseased liver tissue is not clear. We show that human iPSC-derived hepatic cells at various differentiation stages can engraft the liver in a mouse transplantation model. Using the same differentiation and transplantation protocols, we also assessed the ability of human iPSCs derived from each of the three developmental germ layer tissues (that is, ectoderm, mesoderm, and endoderm) to regenerate mouse liver. These iPSC lines, with similar but distinct global DNA methylation patterns, differentiated into multistage hepatic cells with an efficiency similar to that of human embryonic stem cells. Human hepatic cells at various differentiation stages derived from iPSC lines of different origins successfully repopulated the liver tissue of mice with liver cirrhosis. They also secreted human-specific liver proteins into mouse blood at concentrations comparable to that of proteins secreted by human primary hepatocytes. Our results demonstrate the engraftment and liver regenerative capabilities of human iPSC-derived multistage hepatic cells in vivo and suggest that human iPSCs of distinct origins and regardless of their parental epigenetic memory can efficiently differentiate along the hepatic lineage.

  6. Induced pluripotent stem cells (iPSCs) derived from different cell sources and their potential for regenerative and personalized medicine.

    Science.gov (United States)

    Shtrichman, R; Germanguz, I; Itskovitz-Eldor, J

    2013-06-01

    Human induced pluripotent stem cells (hiPSCs) have great potential as a robust source of progenitors for regenerative medicine. The novel technology also enables the derivation of patient-specific cells for applications to personalized medicine, such as for personal drug screening and toxicology. However, the biological characteristics of iPSCs are not yet fully understood and their similarity to human embryonic stem cells (hESCs) is still unresolved. Variations among iPSCs, resulting from their original tissue or cell source, and from the experimental protocols used for their derivation, significantly affect epigenetic properties and differentiation potential. Here we review the potential of iPSCs for regenerative and personalized medicine, and assess their expression pattern, epigenetic memory and differentiation capabilities in relation to their parental tissue source. We also summarize the patient-specific iPSCs that have been derived for applications in biological research and drug discovery; and review risks that must be overcome in order to use iPSC technology for clinical applications.

  7. Fate of iPSCs Derived from Azoospermic and Fertile Men following Xenotransplantation to Murine Seminiferous Tubules

    Directory of Open Access Journals (Sweden)

    Cyril Ramathal

    2014-05-01

    Full Text Available Historically, spontaneous deletions and insertions have provided means to probe germline developmental genetics in Drosophila, mouse and other species. Here, induced pluripotent stem cell (iPSC lines were derived from infertile men with deletions that encompass three Y chromosome azoospermia factor (AZF regions and are associated with production of few or no sperm but normal somatic development. AZF-deleted iPSC lines were compromised in germ cell development in vitro. Undifferentiated iPSCs transplanted directly into murine seminiferous tubules differentiated extensively to germ-cell-like cells (GCLCs that localized near the basement membrane, demonstrated morphology indistinguishable from fetal germ cells, and expressed germ-cell-specific proteins diagnostic of primordial germ cells. Alternatively, all iPSCs that exited tubules formed primitive tumors. iPSCs with AZF deletions produced significantly fewer GCLCs in vivo with distinct defects in gene expression. Findings indicate that xenotransplantation of human iPSCs directs germ cell differentiation in a manner dependent on donor genetic status.

  8. Health and Human Rights in Chin State, Western Burma: A Population-Based Assessment Using Multistaged Household Cluster Sampling

    Science.gov (United States)

    Sollom, Richard; Richards, Adam K.; Parmar, Parveen; Mullany, Luke C.; Lian, Salai Bawi; Iacopino, Vincent; Beyrer, Chris

    2011-01-01

    Background The Chin State of Burma (also known as Myanmar) is an isolated ethnic minority area with poor health outcomes and reports of food insecurity and human rights violations. We report on a population-based assessment of health and human rights in Chin State. We sought to quantify reported human rights violations in Chin State and associations between these reported violations and health status at the household level. Methods and Findings Multistaged household cluster sampling was done. Heads of household were interviewed on demographics, access to health care, health status, food insecurity, forced displacement, forced labor, and other human rights violations during the preceding 12 months. Ratios of the prevalence of household hunger comparing exposed and unexposed to each reported violation were estimated using binomial regression, and 95% confidence intervals (CIs) were constructed. Multivariate models were done to adjust for possible confounders. Overall, 91.9% of households (95% CI 89.7%–94.1%) reported forced labor in the past 12 months. Forty-three percent of households met FANTA-2 (Food and Nutrition Technical Assistance II project) definitions for moderate to severe household hunger. Common violations reported were food theft, livestock theft or killing, forced displacement, beatings and torture, detentions, disappearances, and religious and ethnic persecution. Self reporting of multiple rights abuses was independently associated with household hunger. Conclusions Our findings indicate widespread self-reports of human rights violations. The nature and extent of these violations may warrant investigation by the United Nations or International Criminal Court. Please see later in the article for the Editors' Summary PMID:21346799

  9. Health and human rights in Chin State, Western Burma: a population-based assessment using multistaged household cluster sampling.

    Directory of Open Access Journals (Sweden)

    Richard Sollom

    Full Text Available BACKGROUND: The Chin State of Burma (also known as Myanmar is an isolated ethnic minority area with poor health outcomes and reports of food insecurity and human rights violations. We report on a population-based assessment of health and human rights in Chin State. We sought to quantify reported human rights violations in Chin State and associations between these reported violations and health status at the household level. METHODS AND FINDINGS: Multistaged household cluster sampling was done. Heads of household were interviewed on demographics, access to health care, health status, food insecurity, forced displacement, forced labor, and other human rights violations during the preceding 12 months. Ratios of the prevalence of household hunger comparing exposed and unexposed to each reported violation were estimated using binomial regression, and 95% confidence intervals (CIs were constructed. Multivariate models were done to adjust for possible confounders. Overall, 91.9% of households (95% CI 89.7%-94.1% reported forced labor in the past 12 months. Forty-three percent of households met FANTA-2 (Food and Nutrition Technical Assistance II project definitions for moderate to severe household hunger. Common violations reported were food theft, livestock theft or killing, forced displacement, beatings and torture, detentions, disappearances, and religious and ethnic persecution. Self reporting of multiple rights abuses was independently associated with household hunger. CONCLUSIONS: Our findings indicate widespread self-reports of human rights violations. The nature and extent of these violations may warrant investigation by the United Nations or International Criminal Court. Please see later in the article for the Editors' Summary.

  10. Spatial normalization of ultrahigh resolution 7 T magnetic resonance imaging data of the postmortem human subthalamic nucleus: a multistage approach

    NARCIS (Netherlands)

    Weiss, M; Alkemade, A.; Keuken, M.C.; Müller-Axt, C.; Geyer, S.; Turner, R.; Forstmann, B.U.

    2015-01-01

    In this paper, we describe a novel processing strategy for the spatial normalization of ultrahigh resolution magnetic resonance imaging (MRI) data of small ex vivo samples into MNI standard space. We present a multistage scanning and registration method for data of the subthalamic nucleus (STN) obta

  11. Spatial normalization of ultrahigh resolution 7 T magnetic resonance imaging data of the postmortem human subthalamic nucleus: a multistage approach

    NARCIS (Netherlands)

    Weiss, M; Alkemade, A.; Keuken, M.C.; Müller-Axt, C.; Geyer, S.; Turner, R.; Forstmann, B.U.

    2015-01-01

    In this paper, we describe a novel processing strategy for the spatial normalization of ultrahigh resolution magnetic resonance imaging (MRI) data of small ex vivo samples into MNI standard space. We present a multistage scanning and registration method for data of the subthalamic nucleus (STN) obta

  12. An integrated practical implementation of continuous aqueous two-phase systems for the recovery of human IgG: From the microdevice to a multistage bench-scale mixer-settler device.

    Science.gov (United States)

    Espitia-Saloma, Edith; Vâzquez-Villegas, Patricia; Rito-Palomares, Marco; Aguilar, Oscar

    2016-05-01

    Aqueous two-phase systems (ATPS) are a liquid-liquid extraction technology with clear process benefits; however, its lack of industrial embracement is still a challenge to overcome. Antibodies are a potential product to be recovered by ATPS in a commercial context. The objective of this work is to present a more integral approach of the different isolated strategies that have arisen in order to enable a practical, generic implementation of ATPS, using human immunoglobulin G (IgG) as experimental model. A microfluidic device is used for ATPS parameters preselection for product recovery. ATPS were continuously operated in a mixer-settler device in one stage, multistage and multistage with recirculation configuration. Single-stage pure IgG extraction with a polyethylene glycol (PEG) 3350-phophates ATPS within continuous operation allowed a 65% recovery. Further implementation of a multistage platform promoted a higher particle partitioning reaching a 90% recovery. The processing of IgG from a cell supernatant culture harvest in a multistage system with top phase recirculation resulted in 78% IgG recovery in bottom phase. This work conjugates three not widely spread methodologies for ATPS: microfluidics, continuous and multistage operation.

  13. MULTISTAGE FLUIDIZED BED REACTOR

    Science.gov (United States)

    Jonke, A.A.; Graae, J.E.A.; Levitz, N.M.

    1959-11-01

    A multistage fluidized bed reactor is described in which each of a number of stages is arranged with respect to an associated baffle so that a fluidizing gas flows upward and a granular solid downward through the stages and baffles, whereas the granular solid stopsflowing downward when the flow of fluidizing gas is shut off.

  14. Multistage stochastic optimization

    CERN Document Server

    Pflug, Georg Ch

    2014-01-01

    Multistage stochastic optimization problems appear in many ways in finance, insurance, energy production and trading, logistics and transportation, among other areas. They describe decision situations under uncertainty and with a longer planning horizon. This book contains a comprehensive treatment of today’s state of the art in multistage stochastic optimization.  It covers the mathematical backgrounds of approximation theory as well as numerous practical algorithms and examples for the generation and handling of scenario trees. A special emphasis is put on estimation and bounding of the modeling error using novel distance concepts, on time consistency and the role of model ambiguity in the decision process. An extensive treatment of examples from electricity production, asset liability management and inventory control concludes the book

  15. A Multi-Stage Human Factors and Comfort Assessment of Instrumented Insoles Designed for Use in a Connected Health Infrastructure

    Directory of Open Access Journals (Sweden)

    Richard Harte

    2015-12-01

    Full Text Available Wearable electronics are gaining widespread use as enabling technologies, monitoring human physical activity and behavior as part of connected health infrastructures. Attention to human factors and comfort of these devices can greatly positively influence user experience, with a subsequently higher likelihood of user acceptance and lower levels of device rejection. Here, we employ a human factors and comfort assessment methodology grounded in the principles of human-centered design to influence and enhance the design of an instrumented insole. A use case was developed and interrogated by stakeholders, experts, and end users, capturing the context of use and user characteristics for the instrumented insole. This use case informed all stages of the design process through two full design cycles, leading to the development of an initial version 1 and a later version 2 prototype. Each version of the prototype was subjected to an expert human factors inspection and controlled comfort assessment using human volunteers. Structured feedback from the first cycle of testing was the driver of design changes implemented in the version 2 prototype. This prototype was found to have significantly improved human factors and comfort characteristics over the first version of the prototype. Expert inspection found that many of the original problems in the first prototype had been resolved in the second prototype. Furthermore, a comfort assessment of this prototype with a group of young healthy adults showed it to be indistinguishable from their normal footwear. This study demonstrates the power and effectiveness of human factors and comfort assessment methodologies in influencing and improving the design of wearable devices.

  16. Coupling methods for multistage sampling

    OpenAIRE

    Chauvet, Guillaume

    2015-01-01

    Multistage sampling is commonly used for household surveys when there exists no sampling frame, or when the population is scattered over a wide area. Multistage sampling usually introduces a complex dependence in the selection of the final units, which makes asymptotic results quite difficult to prove. In this work, we consider multistage sampling with simple random without replacement sampling at the first stage, and with an arbitrary sampling design for further stages. We consider coupling ...

  17. Multistage quadratic stochastic programming

    Science.gov (United States)

    Lau, Karen K.; Womersley, Robert S.

    2001-04-01

    Quadratic stochastic programming (QSP) in which each subproblem is a convex piecewise quadratic program with stochastic data, is a natural extension of stochastic linear programming. This allows the use of quadratic or piecewise quadratic objective functions which are essential for controlling risk in financial and project planning. Two-stage QSP is a special case of extended linear-quadratic programming (ELQP). The recourse functions in QSP are piecewise quadratic convex and Lipschitz continuous. Moreover, they have Lipschitz gradients if each QP subproblem is strictly convex and differentiable. Using these properties, a generalized Newton algorithm exhibiting global and superlinear convergence has been proposed recently for the two stage case. We extend the generalized Newton algorithm to multistage QSP and show that it is globally and finitely convergent under suitable conditions. We present numerical results on randomly generated data and modified publicly available stochastic linear programming test sets. Efficiency schemes on different scenario tree structures are discussed. The large-scale deterministic equivalent of the multistage QSP is also generated and their accuracy compared.

  18. Deconstruction of Activity-Dependent Covalent Modification of Heme in Human Neutrophil Myeloperoxidase by Multistage Mass Spectrometry (MS[superscript 4])

    Energy Technology Data Exchange (ETDEWEB)

    Geoghegan, Kieran F.; Varghese, Alison H.; Feng, Xidong; Bessire, Andrew J.; Conboy, James J.; Ruggeri, Roger B.; Ahn, Kay; Spath, Samantha N.; Filippov, Sergey V.; Conrad, Steven J.; Carpino, Philip A.; Guimarães, Cristiano R.W.; Vajdos, Felix F. (Pfizer)

    2013-03-07

    Myeloperoxidase (MPO) is known to be inactivated and covalently modified by treatment with hydrogen peroxide and agents similar to 3-(2-ethoxypropyl)-2-thioxo-2,3-dihydro-1H-purin-6(9H)-one (1), a 254.08 Da derivative of 2-thioxanthine. Peptide mapping by liquid chromatography and mass spectrometry detected modification by 1 in a labile peptide-heme-peptide fragment of the enzyme, accompanied by a mass increase of 252.08 Da. The loss of two hydrogen atoms was consistent with mechanism-based oxidative coupling. Multistage mass spectrometry (MS{sup 4}) of the modified fragment in an ion trap/Orbitrap spectrometer demonstrated that 1 was coupled directly to heme. Use of a 10 amu window delivered the full isotopic envelope of each precursor ion to collision-induced dissociation, preserving definitive isotopic profiles for iron-containing fragments through successive steps of multistage mass spectrometry. Iron isotope signatures and accurate mass measurements supported the structural assignments. Crystallographic analysis confirmed linkage between the methyl substituent of the heme pyrrole D ring and the sulfur atom of 1. The final orientation of 1 perpendicular to the plane of the heme ring suggested a mechanism consisting of two consecutive one-electron oxidations of 1 by MPO. Multistage mass spectrometry using stage-specific collision energies permits stepwise deconstruction of modifications of heme enzymes containing covalent links between the heme group and the polypeptide chain.

  19. Multistage Relaying Using Interference Networks

    CERN Document Server

    Muthuramalingam, Bama; Thangaraj, Andrew

    2010-01-01

    Wireless networks with multiple nodes that relay information from a source to a destination are expected to be deployed in many applications. Therefore, understanding their design and performance under practical constraints is important. In this work, we propose and study three multihopping decode and forward (MDF) protocols for multistage half-duplex relay networks with no direct link between the source and destination nodes. In all three protocols, we assume no cooperation across relay nodes for encoding and decoding. Numerical evaluation in illustrative example networks and comparison with cheap relay cut-set bounds for half-duplex networks show that the proposed MDF protocols approach capacity in some ranges of channel gains. The main idea in the design of the protocols is the use of coding in interference networks that are created in different states or modes of a half-duplex network. Our results suggest that multistage half-duplex relaying with practical constraints on cooperation is comparable to point...

  20. Stator Indexing in Multistage Compressors

    Science.gov (United States)

    Barankiewicz, Wendy S.

    1997-01-01

    The relative circumferential location of stator rows (stator indexing) is an aspect of multistage compressor design that has not yet been explored for its potential impact on compressor aerodynamic performance. Although the inlet stages of multistage compressors usually have differing stator blade counts, the aft stages of core compressors can often have stage blocks with equal stator blade counts in successive stages. The potential impact of stator indexing is likely greatest in these stages. To assess the performance impact of stator indexing, researchers at the NASA Lewis Research Center used the 4 ft diameter, four-stage NASA Low Speed Axial Compressor for detailed experiments. This compressor has geometrically identical stages that can circumferentially index stator rows relative to each other in a controlled manner; thus it is an ideal test rig for such investigations.

  1. Multistage Turbomachinery Flows Simulated Numerically

    Science.gov (United States)

    Hathaway, Michael D.; Adamczyk, John J.; Shabbir, Aamir; Wellborn, Steven R.

    1999-01-01

    At the NASA Lewis Research Center, a comprehensive assessment was made of the predictive capability of the average passage flow model as applied to multistage axial-flow compressors. This model, which describes the time-averaged flow field within a typical passage of a blade row embedded in a multistage configuration, is being widely used throughout U.S. aircraft industry as an integral part of their design systems. Rotor flow-angle deviation. In this work, detailed data taken within a four and one-half stage large low-speed compressor were used to assess the weaknesses and strengths of the predictive capabilities of the average passage flow model. The low-speed compressor blading is of modern design and employs stator end-bends. Measurements were made with slow- and high response instrumentation. The high-response measurements revealed the velocity components of both the rotor and stator wakes. From the measured wake profiles, we found that the flow exiting the rotors deviated from the rotor exit metal angle to a lesser degree than was predicted by the average passage flow model. This was found to be due to blade boundary layer transition, which recently has been shown to exist on multistage axial compressor rotor and stator blades, but was not accounted for in the average passage model. Consequently, a model that mimics the effects of blade boundary layer transition, Shih k-epsilon model, was incorporated into the average passage model. Simulations that incorporated this transition model showed a dramatic improvement in agreement with data. The altered model thus improved predictive capability for multistage axial-flow compressors, and this was verified by detailed experimental measurement.

  2. Multi-stage flash degaser

    Science.gov (United States)

    Rapier, Pascal M.

    1982-01-01

    A multi-stage flash degaser (18) is incorporated in an energy conversion system (10) having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger (22) in order that the heat exchanger (22) and a turbine (48) and condenser (32) of the system (10) can operate at optimal efficiency.

  3. Optimization Problem of Multistage Rocket

    Directory of Open Access Journals (Sweden)

    V. B. Tawakley

    1972-04-01

    Full Text Available The necessary conditions for the existence of minimum of a function of initial and final values of mass, position and velocity components and time of a multistage rocket have been reviewed when the thrust levels in each stage are considered to bounded and variation in gravity with height has been taken into account. The nature of the extremal subarcs comprising the complete extremal are has been studied. A few simple examples have been given as illustrations.

  4. Interconnected Levels of Multi-Stage Marketing

    DEFF Research Database (Denmark)

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    must not only decide in general on the merits of multi-stage marketing for their firm, but must also decide on which level they will engage in multi-stage marketing. The triadic perspective enables a rich and multi-dimensional understanding of how different business relationships influence each other......Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes...... different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. The results from the case study indicate that multi-stage marketing exists on different levels. Thus, managers...

  5. Multistage Pressure-Retarded Osmosis

    Science.gov (United States)

    Bharadwaj, Devesh; Fyles, Thomas M.; Struchtrup, Henning

    2016-10-01

    One promising sustainable energy source is the chemical potential difference between salt and freshwater. The membrane process of pressure-retarded osmosis (PRO) has been the most widely investigated means to harvest salinity gradient energy. In this report, we analyse the thermodynamic efficiency of multistage PRO systems to optimize energy recovery from a salinity gradient. We establish a unified description of the efficiencies of the component pumps (P), turbines (T), pressure exchangers (PX), and membrane modules (M) and exploit this model to determine the maximum available work with respect to the volume of the brine produced, the volume of the sea water consumed, or the volume of the freshwater that permeates the membrane. In an idealized series configuration of 1-20 modules (P-M-T), the three optimization conditions have significantly different intermediate operating pressures in the modules, but demonstrate that multistage systems can recover a significantly larger fraction of the available work compared to single-stage PRO. The biggest proportional advantage occurs for one to three modules in series. The available work depends upon the component efficiencies, but the proportional advantage of multistage PRO is retained. We also optimize one- and two-stage PX-M-T and P-M-T configurations with respect to the three volume parameters, and again significantly different optimal operating conditions are found. PX-M-T systems are more efficient than P-M-T systems, and two-stage systems have efficiency advantages that transcend assumed component efficiencies. The results indicate that overall system design with a clear focus on critical optimization parameters has the potential to significantly improve the near-term practical feasibility of PRO.

  6. Simulation of Multistage Turbine Flows

    Science.gov (United States)

    Celestina, M. L.; Mulac, R. A.; Adamczyk, J. J.

    1985-01-01

    The numerical simulation of turbine flows serves to enhance the understanding of the flow phenomena within multistage turbomachinery components. The direct benefit of this activity is improved modeling capability, which can be used to improve component efficiency and durability. A hierarchy of equations was formulated to assess the difficulty in analyzing the flow field within multistage turbomachinery components. The Navier-Stokes equations provides the most complete description. The simplest description is given by a set of equations that govern the quasi-one-dimensional flow. The number of unknowns to be solved for increases monotonically above the number of equations. The development of the additional set of equations needed to mathematically close the system of equations forms the closure problem associated with that level of description. For the Navier-Stokes equation there is no closure problem. For the quasi-one-dimensional equation set random flow fluctuations, unsteady fluctuations, nonaxisymmetric flow variations, and hub-to-shroud variations on the quasi-one-dimensional flow must be accounted for.

  7. Biologically based multistage modeling of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of

  8. Interconnected Levels of Multi-Stage Marketing

    DEFF Research Database (Denmark)

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. The results from the case study indicate that multi-stage marketing exists on different levels. Thus, managers...... in a multi-stage marketing context. This understanding assists managers in assessing and balancing different aspects of multi- stage marketing. The triadic perspective also offers avenues for further research.......Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes...

  9. Multistage Campaigning in Social Networks

    CERN Document Server

    Farajtabar, Mehrdad; Harati, Sahar; Song, Le; Zha, Hongyuan

    2016-01-01

    We consider the problem of how to optimize multi-stage campaigning over social networks. The dynamic programming framework is employed to balance the high present reward and large penalty on low future outcome in the presence of extensive uncertainties. In particular, we establish theoretical foundations of optimal campaigning over social networks where the user activities are modeled as a multivariate Hawkes process, and we derive a time dependent linear relation between the intensity of exogenous events and several commonly used objective functions of campaigning. We further develop a convex dynamic programming framework for determining the optimal intervention policy that prescribes the required level of external drive at each stage for the desired campaigning result. Experiments on both synthetic data and the real-world MemeTracker dataset show that our algorithm can steer the user activities for optimal campaigning much more accurately than baselines.

  10. Multi-stage complex contagions

    Science.gov (United States)

    Melnik, Sergey; Ward, Jonathan A.; Gleeson, James P.; Porter, Mason A.

    2013-03-01

    The spread of ideas across a social network can be studied using complex contagion models, in which agents are activated by contact with multiple activated neighbors. The investigation of complex contagions can provide crucial insights into social influence and behavior-adoption cascades on networks. In this paper, we introduce a model of a multi-stage complex contagion on networks. Agents at different stages—which could, for example, represent differing levels of support for a social movement or differing levels of commitment to a certain product or idea—exert different amounts of influence on their neighbors. We demonstrate that the presence of even one additional stage introduces novel dynamical behavior, including interplay between multiple cascades, which cannot occur in single-stage contagion models. We find that cascades—and hence collective action—can be driven not only by high-stage influencers but also by low-stage influencers.

  11. Health and human rights in eastern Myanmar after the political transition: a population-based assessment using multistaged household cluster sampling.

    Directory of Open Access Journals (Sweden)

    Parveen Kaur Parmar

    Full Text Available Myanmar transitioned to a nominally civilian parliamentary government in March 2011. Qualitative reports suggest that exposure to violence and displacement has declined while international assistance for health services has increased. An assessment of the impact of these changes on the health and human rights situation has not been published.Five community-based organizations conducted household surveys using two-stage cluster sampling in five states in eastern Myanmar from July 2013-September 2013. Data was collected from 6, 178 households on demographics, mortality, health outcomes, water and sanitation, food security and nutrition, malaria, and human rights violations (HRV. Among children aged 6-59 months screened, the prevalence of global acute malnutrition (representing moderate or severe malnutrition was 11.3% (8.0-14.7. A total of 250 deaths occurred during the year prior to the survey. Infant deaths accounted for 64 of these (IMR 94.2; 95% CI 66.5-133.5 and there were 94 child deaths (U5MR 141.9; 95% CI 94.8-189.0. 10.7% of households (95% CI 7.0-14.5 experienced at least one HRV in the past year, while four percent reported 2 or more HRVs. Household exposure to one or more HRVs was associated with moderate-severe malnutrition among children (14.9 vs. 6.8%; prevalence ratio 2.2, 95% CI 1.2-4.2. Household exposure to HRVs was associated with self-reported fair or poor health status among respondents (PR 1.3; 95% CI 1.1-1.5.This large survey of health and human rights demonstrates that two years after political transition, vulnerable populations of eastern Myanmar are less likely to experience human rights violations compared to previous surveys. However, access to health services remains constrained, and risk of disease and death remains higher than the country as a whole. Efforts to address these poor health indicators should prioritize support for populations that remain outside the scope of most formal government and donor programs.

  12. Fuzzy-like multiple objective multistage decision making

    CERN Document Server

    Xu, Jiuping

    2014-01-01

    Decision has inspired reflection of many thinkers since the ancient times. With the rapid development of science and society, appropriate dynamic decision making has been playing an increasingly important role in many areas of human activity including engineering, management, economy and others. In most real-world problems, decision makers usually have to make decisions sequentially at different points in time and space, at different levels for a component or a system, while facing multiple and conflicting objectives and a hybrid uncertain environment where fuzziness and randomness co-exist in a decision making process. This leads to the development of fuzzy-like multiple objective multistage decision making. This book provides a thorough understanding of the concepts of dynamic optimization from a modern perspective and presents the state-of-the-art methodology for modeling, analyzing and solving the most typical multiple objective multistage decision making practical application problems under fuzzy-like un...

  13. Charcoal Production via Multistage Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Adetoyese Olajire Oyedun; Ka Leung Lam; Chi Wai Hui

    2012-01-01

    Interests in charcoal usage have recently been re-ignited because it is believed that charcoal is a muchbetter fuel than wood. The conventional charcoal production consumes a large amount of energy due to the prolonged heating time and cooling time which contribute to the process completing in one to several days. Wood py-rolysis consists of both endothermic and exothermic reactions as well as the decomposition of the different components at different temperature range (hemicellulose: 200-260℃; cellulose: 240-350℃ and lignin: 280-500℃). Inthis study we propose a multistagepyrolysis which is an approach to carry out pyrolysis with multiple heating stages so as to gain certain processing benefits. We propose a three-stage approach which includes rapid stepwise heating stage to a variable target temperatures of 250 ℃, 300℃, 350 ℃ and 400 ℃, slow and gradual heatingstage to a tinal temperature of 400℃ and adiabatic with cooling stage. The multi-stage pyrolysis process can save 30% energy and the processing time by using a first temperature target of 300 ℃and heating rate of 5℃.min-1 to produce a fixed-carbon yield of 25.73% as opposed to the base case with a fixed-carbon yield of23.18%.

  14. Split-plot designs for multistage experimentation

    DEFF Research Database (Denmark)

    Kulahci, Murat; Tyssedal, John

    2016-01-01

    at the same time will be more efficient. However, there have been only a few attempts in the literature to provide an adequate and easy-to-use approach for this problem. In this paper, we present a novel methodology for constructing two-level split-plot and multistage experiments. The methodology is based...... be accommodated in each stage. Furthermore, split-plot designs for multistage experiments with good projective properties are also provided....

  15. Experiments for Multi-Stage Processes

    DEFF Research Database (Denmark)

    Tyssedal, John; Kulahci, Murat

    2015-01-01

    Multi-stage processes are very common in both process and manufacturing industries. In this article we present a methodology for designing experiments for multi-stage processes. Typically in these situations the design is expected to involve many factors from different stages. To minimize...... the required number of experimental runs, we suggest using mirror image pairs of experiments at each stage following the first. As the design criterion, we consider their projectivity and mainly focus on projectivity 3 designs. We provide the methodology for generating these designs for processes with any...

  16. Multi-Stage Programs are Generalized Arrows

    CERN Document Server

    Megacz, Adam

    2010-01-01

    The lambda calculus, subject to typing restrictions, provides a syn- tax for the internal language of cartesian closed categories. This paper establishes a parallel result: staging annotations, subject to named level restrictions, provide a syntax for the internal language of Freyd categories, which are known to be in one-to-one correspondence with Arrows. The connection is made by interpreting multi-stage type systems as indexed functors from polynomial categories to their reindexings (Definitions 15 and 16). This result applies only to multi-stage languages which are (1) homogeneous, (2) allow cross-stage persistence and (3) place no restrictions on the use of structural rules in typing derivations. Removing these restrictions and repeating the construction yields generalized arrows, of which Arrows are a particular case. A translation from well-typed multi-stage programs to single-stage GArrow terms is provided. The translation is defined by induction on the structure of the proof that the multi-stage prog...

  17. A Multistage Approach for Image Registration.

    Science.gov (United States)

    Bowen, Francis; Hu, Jianghai; Du, Eliza Yingzi

    2016-09-01

    Successful image registration is an important step for object recognition, target detection, remote sensing, multimodal content fusion, scene blending, and disaster assessment and management. The geometric and photometric variations between images adversely affect the ability for an algorithm to estimate the transformation parameters that relate the two images. Local deformations, lighting conditions, object obstructions, and perspective differences all contribute to the challenges faced by traditional registration techniques. In this paper, a novel multistage registration approach is proposed that is resilient to view point differences, image content variations, and lighting conditions. Robust registration is realized through the utilization of a novel region descriptor which couples with the spatial and texture characteristics of invariant feature points. The proposed region descriptor is exploited in a multistage approach. A multistage process allows the utilization of the graph-based descriptor in many scenarios thus allowing the algorithm to be applied to a broader set of images. Each successive stage of the registration technique is evaluated through an effective similarity metric which determines subsequent action. The registration of aerial and street view images from pre- and post-disaster provide strong evidence that the proposed method estimates more accurate global transformation parameters than traditional feature-based methods. Experimental results show the robustness and accuracy of the proposed multistage image registration methodology.

  18. Automated Simultaneous Assembly for Multistage Testing

    Science.gov (United States)

    Breithaupt, Krista; Ariel, Adelaide; Veldkamp, Bernard P.

    2005-01-01

    This article offers some solutions used in the assembly of the computerized Uniform Certified Public Accountancy (CPA) licensing examination as practical alternatives for operational programs producing large numbers of forms. The Uniform CPA examination was offered as an adaptive multistage test (MST) beginning in April of 2004. Examples of…

  19. Some LCP Decompositions of Multistage Interconnection Networks

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Some useful layered cross product decompositons are derived both for general bit permutation networks and for(2n-1)-stage multistage interconnection networks. Several issues in related works are clarified and the rearrangeability of some interesting networks are considered. In particular, the rearrangeability of one class of networks is formulated as a new type of combinatorial design problmes.

  20. Interconnected levels of multi-stage marketing: A triadic approach

    OpenAIRE

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. ...

  1. Interconnected levels of multi-stage marketing: A triadic approach

    OpenAIRE

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. ...

  2. [Variance estimation considering multistage sampling design in multistage complex sample analysis].

    Science.gov (United States)

    Li, Yichong; Zhao, Yinjun; Wang, Limin; Zhang, Mei; Zhou, Maigeng

    2016-03-01

    Multistage sampling is a frequently-used method in random sampling survey in public health. Clustering or independence between observations often exists in the sampling, often called complex sample, generated by multistage sampling. Sampling error may be underestimated and the probability of type I error may be increased if the multistage sample design was not taken into consideration in analysis. As variance (error) estimator in complex sample is often complicated, statistical software usually adopt ultimate cluster variance estimate (UCVE) to approximate the estimation, which simply assume that the sample comes from one-stage sampling. However, with increased sampling fraction of primary sampling unit, contribution from subsequent sampling stages is no more trivial, and the ultimate cluster variance estimate may, therefore, lead to invalid variance estimation. This paper summarize a method of variance estimation considering multistage sampling design. The performances are compared with UCVE and the method considering multistage sampling design by simulating random sampling under different sampling schemes using real world data. Simulation showed that as primary sampling unit (PSU) sampling fraction increased, UCVE tended to generate increasingly biased estimation, whereas accurate estimates were obtained by using the method considering multistage sampling design.

  3. Manipulating Multistage Interconnection Networks Using Fundamental Arrangements

    Directory of Open Access Journals (Sweden)

    E. Gur

    2010-12-01

    Full Text Available Optimizing interconnection networks is a prime object in switching schemes. In this work the authors present a novel approach for obtaining a required channel arrangement in a multi-stage interconnectionnetwork, using a new concept – a fundamental arrangement. The fundamental arrangement is an initial N-1 stage switch arrangement that allows obtaining any required output channel arrangement given an input arrangement, using N/2 binary switches at each stage. The paper demonstrates how a fundamental arrangement can be achieved and how, once this is done, any required arrangement may be obtained within 2(N-1 steps.

  4. Conditional statistical inference with multistage testing designs.

    Science.gov (United States)

    Zwitser, Robert J; Maris, Gunter

    2015-03-01

    In this paper it is demonstrated how statistical inference from multistage test designs can be made based on the conditional likelihood. Special attention is given to parameter estimation, as well as the evaluation of model fit. Two reasons are provided why the fit of simple measurement models is expected to be better in adaptive designs, compared to linear designs: more parameters are available for the same number of observations; and undesirable response behavior, like slipping and guessing, might be avoided owing to a better match between item difficulty and examinee proficiency. The results are illustrated with simulated data, as well as with real data.

  5. Exposure Control Using Adaptive Multi-Stage Item Bundles.

    Science.gov (United States)

    Luecht, Richard M.

    This paper presents a multistage adaptive testing test development paradigm that promises to handle content balancing and other test development needs, psychometric reliability concerns, and item exposure. The bundled multistage adaptive testing (BMAT) framework is a modification of the computer-adaptive sequential testing framework introduced by…

  6. The numerical simulation of multistage turbomachinery flows

    Science.gov (United States)

    Adamczyk, John J.; Beach, T. A.; Celestina, M. L.; Mulac, R. A.; To, W. M.

    1996-01-01

    The effect of the unsteady flow field in a multistage compressor on the time-averaged performance was assessed. The energy transport by the unsteady deterministic flow field was taken into account. The magnitude of the body force resulting from the aerodynamic loading on a blade row was compared to the gradient of the stress tensor associated with the unsteady time-resolved flow field generated by the blade row. The magnitude of the work performed by these forces was compared to the divergence of the energy correlations produced by the unsteady time-resolved flow field. The stress tensor and the energy correlations are non-negligible in the end wall regions. The results suggest that the turbulence is the primary source of flow mixing in the midspan region.

  7. Condition monitoring of multistage printing presses

    Science.gov (United States)

    Wang, W.; Golnaraghi, F.; Ismail, F.

    2004-03-01

    The main concern in printing quality in multistage presses is doubling. Doubling is caused by imperfections either within stages (units) or in links connecting different stages, mainly resulting from machine vibration, gear damage, and excessive run-out. In this paper, we propose new means for printing quality control via geared system health condition monitoring. The diagnosis is based on the signals acquired from inexpensive magnetic pickups. A new technique is developed to monitor the gear rotation synchronization among different stages in order to isolate possible sources of the doubling problem. A new approach is proposed to determine the gear run-out. Moreover, gear tooth damage detection is conducted using the beta kurtosis and the continuous wavelet transform based on the overall residual signal. The beta kurtosis of original signal average is also shown here to be useful in detecting excessive gear run-out. Test results from printing presses demonstrated the viability of the proposed methods.

  8. Optimal Multistage Algorithm for Adjoint Computation

    Energy Technology Data Exchange (ETDEWEB)

    Aupy, Guillaume; Herrmann, Julien; Hovland, Paul; Robert, Yves

    2016-01-01

    We reexamine the work of Stumm and Walther on multistage algorithms for adjoint computation. We provide an optimal algorithm for this problem when there are two levels of checkpoints, in memory and on disk. Previously, optimal algorithms for adjoint computations were known only for a single level of checkpoints with no writing and reading costs; a well-known example is the binomial checkpointing algorithm of Griewank and Walther. Stumm and Walther extended that binomial checkpointing algorithm to the case of two levels of checkpoints, but they did not provide any optimality results. We bridge the gap by designing the first optimal algorithm in this context. We experimentally compare our optimal algorithm with that of Stumm and Walther to assess the difference in performance.

  9. Vibration signature analysis of multistage gear transmission

    Science.gov (United States)

    Choy, F. K.; Tu, Y. K.; Savage, M.; Townsend, D. P.

    1989-01-01

    An analysis is presented for multistage multimesh gear transmission systems. The analysis predicts the overall system dynamics and the transmissibility to the gear box or the enclosed structure. The modal synthesis approach of the analysis treats the uncoupled lateral/torsional model characteristics of each stage or component independently. The vibration signature analysis evaluates the global dynamics coupling in the system. The method synthesizes the interaction of each modal component or stage with the nonlinear gear mesh dynamics and the modal support geometry characteristics. The analysis simulates transient and steady state vibration events to determine the resulting torque variations, speeds, changes, rotor imbalances, and support gear box motion excitations. A vibration signature analysis examines the overall dynamic characteristics of the system, and the individual model component responses. The gear box vibration analysis also examines the spectral characteristics of the support system.

  10. Probabilistic Analysis of Multistage Interconnection Network Performance

    Science.gov (United States)

    1992-04-01

    out itndep~endlence of channel loads has b~een pie -co.nr)tited. and channels have been assigned itatnes genleratedl from thle namies of the their nodes...lthe exam pie below: > (setq d8x8 (parse-multistage-network determinist ically-interwired-8x8-rep)) (HA PTER I. j1I:1?F� Nx(’l0 A ( I’ . iI’l.I...performs considerably worse than either. (71.1 I’TI’) I . tI’IIOXI.I.IJTO.\\’.0’ -)? A1 I’L TIPO I’ll Xl7J0IK.K 71 Throughput 12 1 10 8 O 6 4 2 0 0.2 0.4

  11. Model equation for simulating flows in multistage turbomachinery

    Science.gov (United States)

    Adamczyk, J. J.

    1985-01-01

    A steady, three-dimensional average-passage equation system is derived for use in simulating multistage turbomachinery flows. These equations describe a steady, viscous flow that is periodic from blade passage to blade passage. From this system of equations, various reduced forms can be derived for use in simulating the three-dimensional flow field within multistage machinery. It is suggested that a properly scaled form of the averaged-passage equation system would provide an improved mathematical model for simulating the flow in multistage machines at design and, in particular, at off-design conditions.

  12. Aerodynamics and flow characterisation of multistage rockets

    Science.gov (United States)

    Srinivas, G.; Prakash, M. V. S.

    2017-05-01

    The main objective of this paper is to conduct a systematic flow analysis on single, double and multistage rockets using ANSYS software. Today non-air breathing propulsion is increasing dramatically for the enhancement of space exploration. The rocket propulsion is playing vital role in carrying the payload to the destination. Day to day rocket aerodynamic performance and flow characterization analysis has becoming challenging task to the researchers. Taking this task as motivation a systematic literature is conducted to achieve better aerodynamic and flow characterization on various rocket models. The analyses on rocket models are very little especially in numerical side and experimental area. Each rocket stage analysis conducted for different Mach numbers and having different flow varying angle of attacks for finding the critical efficiency performance parameters like pressure, density and velocity. After successful completion of the analysis the research reveals that flow around the rocket body for Mach number 4 and 5 best suitable for designed payload. Another major objective of this paper is to bring best aerodynamics flow characterizations in both aero and mechanical features. This paper also brings feature prospectus of rocket stage technology in the field of aerodynamic design.

  13. Performance of multistage filtration using different filter media ...

    African Journals Online (AJOL)

    Performance of multistage filtration using different filter media against conventional water treatment systems. ... horizontal flow roughing filter (HRF)) as an alternative water treatment technology to the conventional one. A pilot- ... Article Metrics.

  14. PARALLEL MULTI-STAGE & MULTI-STEP METHOD IN ODES

    Institute of Scientific and Technical Information of China (English)

    Xiao-qiu Song

    2000-01-01

    In this paper, the theory of parallel multi-stage & multi-step method is dis cussed, which is a form of combining Runge-Kutta method with linear multi-step method that can be used for parallel computation.

  15. Using the multistage cube network topology in parallel supercomputers

    Energy Technology Data Exchange (ETDEWEB)

    Siegel, H.J.; Nation, W.G. (Purdue Univ., Lafayette, IN (USA). School of Electrical Engineering); Kruskal, C.P. (Maryland Univ., College Park, MD (USA). Dept. of Computer Science); Napolitano, L.M. Jr. (Sandia National Labs., Livermore, CA (USA))

    1989-12-01

    A variety of approaches to designing the interconnection network to support communications among the processors and memories of supercomputers employing large-scale parallel processing have been proposed and/or implemented. These approaches are often based on the multistage cube topology. This topology is the subject of much ongoing research and study because of the ways in which the multistage cube can be used. The attributes of the topology that make it useful are described. These include O(N log{sub 2} N) cost for an N input/output network, decentralized control, a variety of implementation options, good data permuting capability to support single instruction stream/multiple data stream (SIMD) parallelism, good throughput to support multiple instruction stream/multiple data stream (MIMD) parallelism, and ability to be partitioned into independent subnetworks to support reconfigurable systems. Examples of existing systems that use multistage cube networks are overviewed. The multistage cube topology can be converted into a single-stage network by associating with each switch in the network a processor (and a memory). Properties of systems that use the multistage cube network in this way are also examined.

  16. Model equations for simulating flows in multistage turbomachinery

    Science.gov (United States)

    Adamczyk, John J.

    1996-01-01

    A steady, three dimensional average-passage equation system was derived. The purpose was to simulate multistage turbomachinery flows. These equations describe a steady, viscous flow that is periodic from blade passage to blade passage. Moreover, these equations have a closure problem that is similar to that of the Reynolds-average Navier-Stokes equations. A scaled form of the average-passage equation system could provide an improved mathematical model for simulating the flow in the design and in the off-design conditions of a multistage machine.

  17. Vehicle Routing Problem Solving Method for a Cooperative Logistics Network by Using Multi-Stage GA

    Science.gov (United States)

    Onoyama, Takashi; Maekawa, Takuya; Kubota, Sen; Tsuruta, Setsuo; Komoda, Norihisa

    A GA applied VRP (Vehicle Routing Problem) solving-method which realizes optimization of a cooperative logistics network is proposed. For this optimization a VRP solving-method that can obtain human expert-level solution, which realizes steady logistics operation, in interactive response time is required. The multi-stage GA enables to obtain the accurate solution under both hard and weak time constraints in interactive response time. Moreover, to realize the stable logistics operation, the daily fluctuation of shipping volume is taken into the fitness value of each individual in GA. The experimental result reveals the proposed method obtains the accurate solution that realizes the stable operation in interactive response time.

  18. Information Overload in Multi-Stage Selection Procedures

    NARCIS (Netherlands)

    S.S. Ficco (Stefano); V.A. Karamychev (Vladimir)

    2004-01-01

    textabstractThe paper studies information processing imperfections in a fully rational decision-making network. It is shown that imperfect information transmission and imperfect information acquisition in a multi-stage selection game yield information overload. The paper analyses the mechanisms resp

  19. Information Overload in Multi-Stage Selection Procedures

    NARCIS (Netherlands)

    S.S. Ficco (Stefano); V.A. Karamychev (Vladimir)

    2004-01-01

    textabstractThe paper studies information processing imperfections in a fully rational decision-making network. It is shown that imperfect information transmission and imperfect information acquisition in a multi-stage selection game yield information overload. The paper analyses the mechanisms

  20. Using break quantities for tactical optimisation in multistage distribution systems

    NARCIS (Netherlands)

    M.J. Kleijn (Marcel); R. Dekker (Rommert)

    1997-01-01

    textabstractIn this chapter we discuss a tactical optimisation problem that arises in a multistage distribution system where customer orders can be delivered from any stockpoint. A simple rule to allocate orders to locations is a break quantity rule, which routes large orders to higher-stage stockpo

  1. 76 FR 19747 - Grant of Authority for Subzone Status; Grundfos Pumps Manufacturing Corporation (Multi-Stage...

    Science.gov (United States)

    2011-04-08

    ... (Multi-Stage Centrifugal Pumps); Allentown, PA Pursuant to its authority under the Foreign-Trade Zones... to the Board for authority to establish a special-purpose subzone at the multi-stage centrifugal pump... status for activity related to the manufacturing of multi-stage centrifugal pumps at the Grundfos...

  2. Generation of induced pluripotent stem cells from human cord blood.

    Science.gov (United States)

    Haase, Alexandra; Olmer, Ruth; Schwanke, Kristin; Wunderlich, Stephanie; Merkert, Sylvia; Hess, Christian; Zweigerdt, Robert; Gruh, Ina; Meyer, Johann; Wagner, Stefan; Maier, Lars S; Han, Dong Wook; Glage, Silke; Miller, Konstantin; Fischer, Philipp; Schöler, Hans R; Martin, Ulrich

    2009-10-02

    Induced pluripotent stem cells (iPSCs) may represent an ideal cell source for future regenerative therapies. A critical issue concerning the clinical use of patient-specific iPSCs is the accumulation of mutations in somatic (stem) cells over an organism's lifetime. Acquired somatic mutations are passed onto iPSCs during reprogramming and may be associated with loss of cellular functions and cancer formation. Here we report the generation of human iPSCs from cord blood (CB) as a juvenescent cell source. CBiPSCs show characteristics typical of embryonic stem cells and can be differentiated into derivatives of all three germ layers, including functional cardiomyocytes. For future therapeutic production of autologous and allogeneic iPSC derivatives, CB could be routinely harvested for public and commercial CB banks without any donor risk. CB could readily become available for pediatric patients and, in particular, for newborns with genetic diseases or congenital malformations.

  3. Human finger-prick induced pluripotent stem cells facilitate the development of stem cell banking.

    Science.gov (United States)

    Tan, Hong-Kee; Toh, Cheng-Xu Delon; Ma, Dongrui; Yang, Binxia; Liu, Tong Ming; Lu, Jun; Wong, Chee-Wai; Tan, Tze-Kai; Li, Hu; Syn, Christopher; Tan, Eng-Lee; Lim, Bing; Lim, Yoon-Pin; Cook, Stuart A; Loh, Yuin-Han

    2014-05-01

    Induced pluripotent stem cells (iPSCs) derived from somatic cells of patients can be a good model for studying human diseases and for future therapeutic regenerative medicine. Current initiatives to establish human iPSC (hiPSC) banking face challenges in recruiting large numbers of donors with diverse diseased, genetic, and phenotypic representations. In this study, we describe the efficient derivation of transgene-free hiPSCs from human finger-prick blood. Finger-prick sample collection can be performed on a "do-it-yourself" basis by donors and sent to the hiPSC facility for reprogramming. We show that single-drop volumes of finger-prick samples are sufficient for performing cellular reprogramming, DNA sequencing, and blood serotyping in parallel. Our novel strategy has the potential to facilitate the development of large-scale hiPSC banking worldwide.

  4. Derivation of Neural Progenitors and Retinal Pigment Epithelium from Common Marmoset and Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Laughing Bear Torrez

    2012-01-01

    Full Text Available Embryonic and induced pluripotent stem cells (IPSCs derived from mammalian species are valuable tools for modeling human disease, including retinal degenerative eye diseases that result in visual loss. Restoration of vision has focused on transplantation of neural progenitor cells (NPCs and retinal pigmented epithelium (RPE to the retina. Here we used transgenic common marmoset (Callithrix jacchus and human pluripotent stem cells carrying the enhanced green fluorescent protein (eGFP reporter as a model system for retinal differentiation. Using suspension and subsequent adherent differentiation cultures, we observed spontaneous in vitro differentiation that included NPCs and cells with pigment granules characteristic of differentiated RPE. Retinal cells derived from human and common marmoset pluripotent stem cells provide potentially unlimited cell sources for testing safety and immune compatibility following autologous or allogeneic transplantation using nonhuman primates in early translational applications.

  5. Various multistage ensembles for prediction of heating energy consumption

    Directory of Open Access Journals (Sweden)

    Radisa Jovanovic

    2015-04-01

    Full Text Available Feedforward neural network models are created for prediction of daily heating energy consumption of a NTNU university campus Gloshaugen using actual measured data for training and testing. Improvement of prediction accuracy is proposed by using neural network ensemble. Previously trained feed-forward neural networks are first separated into clusters, using k-means algorithm, and then the best network of each cluster is chosen as member of an ensemble. Two conventional averaging methods for obtaining ensemble output are applied; simple and weighted. In order to achieve better prediction results, multistage ensemble is investigated. As second level, adaptive neuro-fuzzy inference system with various clustering and membership functions are used to aggregate the selected ensemble members. Feedforward neural network in second stage is also analyzed. It is shown that using ensemble of neural networks can predict heating energy consumption with better accuracy than the best trained single neural network, while the best results are achieved with multistage ensemble.

  6. Multi-stage decoding of multi-level modulation codes

    Science.gov (United States)

    Lin, Shu; Kasami, Tadao; Costello, Daniel J., Jr.

    1991-01-01

    Various types of multi-stage decoding for multi-level modulation codes are investigated. It is shown that if the component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. Particularly, it is shown that the difference in performance between the suboptimum multi-stage soft-decision maximum likelihood decoding of a modulation code and the single-stage optimum soft-decision decoding of the code is very small, only a fraction of dB loss in signal to noise ratio at a bit error rate (BER) of 10(exp -6).

  7. Realization of Multistage FIR Filters using Pipelining-Interleaving

    Directory of Open Access Journals (Sweden)

    M. Ciric

    2012-11-01

    Full Text Available Multistage digital filters can be one of the solutions for the realization of filters with a narrow transition zone. If requirements for the width of transition zone are too strict, then they are the only alternative, and the decimation/interpolation must be performed in several steps. Combining decimation/interpolation operations related to the implementation of multi-channel filters in the PI (pipelining/interleaving technique can give an efficient structure of multichannel multistage filter. Using the advantages offered by newer generations of FPGA chips in terms of digital design structure, it is possible to realize such filters with considerable savings of hardware resources and reduce the effect of finite length codeword. This paper proposes such an efficient implementation and presents the results of such a realization with FPGA components.

  8. Dose-response relationship in multistage carcinogenesis: promoters.

    OpenAIRE

    Kitchin, K T; Brown, J. L.; Setzer, R.W.

    1994-01-01

    Published dose-response curves of promoters of multistage carcinogenesis were selected that met the combined criteria of long study times, multiple doses, and low doses. In rat liver, 12 dose-response studies of 7 different promoters (phenobarbital, 2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD], clophen A-50 (a polychlorinated biphenyl), alpha-, beta-, and gamma-hexachlorocyclohexane [HCH], and chloroform) were selected. These promoters were studied for 7-86 weeks and either altered hepatic foci...

  9. Immunogenicity and in vitro Protective Efficacy of a Recombinant Multistage Plasmodium falciparum Candidate Vaccine

    Science.gov (United States)

    Shi, Ya Ping; Hasnain, Seyed E.; Sacci, John B.; Holloway, Brian P.; Fujioka, Hisashi; Kumar, Nirbhay; Wohlhueter, Robert; Hoffman, Stephen L.; Collins, William E.; Lal, Altaf A.

    1999-02-01

    Compared with a single-stage antigen-based vaccine, a multistage and multivalent Plasmodium falciparum vaccine would be more efficacious by inducing "multiple layers" of immunity. We have constructed a synthetic gene that encodes for 12 B cell, 6 T cell proliferative, and 3 cytotoxic T lymphocyte epitopes derived from 9 stage-specific P. falciparum antigens corresponding to the sporozoite, liver, erythrocytic asexual, and sexual stages. The gene was expressed in the baculovirus system, and a 41-kDa antigen, termed CDC/NIIMALVAC-1, was purified. Immunization in rabbits with the purified protein in the presence of different adjuvants generated antibody responses that recognized vaccine antigen, linear peptides contained in the vaccine, and all stages of P. falciparum. In vitro assays of protection revealed that the vaccine-elicited antibodies strongly inhibited sporozoite invasion of hepatoma cells and growth of blood-stage parasites in the presence of monocytes. These observations demonstrate that a multicomponent, multistage malaria vaccine can induce immune responses that inhibit parasite development at multiple stages. The rationale and approach used in the development of a multicomponent P. falciparum vaccine will be useful in the development of a multispecies human malaria vaccine and vaccines against other infectious diseases.

  10. Numerical Simulation of Flow Instabilities in High Speed Multistage Compressors

    Institute of Scientific and Technical Information of China (English)

    JunHu; ThomasPeters; 等

    1999-01-01

    In the present paper,a nonlinear multi“actuator disk” model is proposed to analyze the dynamic behavior of flow instabilities,including rotating stall and surge,in high speed multistage axial compressors.The model describes the duct flow fields using two dimensional,compressible and unsteady Euler equations,and accounts for the influences of downstream plenum and throttle in the system as well.It replaces each blade row of multistage compressore with a disk.For numerical calculations,the time marching procedure,using MacCormack two steps scheme,is used.The main pupose of this paper is to predict the mechanism of two dimensional short wavelength rotating stall inception and the interation between blade rows in high speed multistage compressors.It has been demonstrated that the model has the ability to predict those phenomena,and the results show that some system parameters have a strong effect on the stall features as well.Results for a five stage high speed compressor are analyzed in detail,and comparison with the experimental data demonstrates that the model and calculating results are reliable.

  11. Interconnected levels of Multi-Stage Marketing – A Triadic approach

    DEFF Research Database (Denmark)

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. The results from the case study indicate that multi-stage marketing exists on different levels. Thus, managers...... must not only decide in general on the merits of multi-stage marketing for their firm, but must also decide on which level they will engage in multi-stage marketing. The triadic perspective enables a rich and multi-dimensional understanding of how different business relationships influence each other......Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes...

  12. Interconnected levels of Multi-Stage Marketing – A Triadic approach

    DEFF Research Database (Denmark)

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    must not only decide in general on the merits of multi-stage marketing for their firm, but must also decide on which level they will engage in multi-stage marketing. The triadic perspective enables a rich and multi-dimensional understanding of how different business relationships influence each other......Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes...... different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. The results from the case study indicate that multi-stage marketing exists on different levels. Thus, managers...

  13. Research on optical multistage butterfly interconnection and optoelectronic logic operations

    Science.gov (United States)

    Sun, De-Gui; Wang, Na-Xin; He, Li-Ming; Xu, Mai; Liang, Guo-Dong; Zheng, Jie

    We briefly study butterfly interconnection construction and propose an experimental approach to implementing multistage butterfly interconnection networks by using a special interconnection grating with the reflection ladder structure and liquid crystal light valves (LCLVs), and implementing the optical butterfly interconnections and primary optical digital logic operations. With this foundation, we analyse and discuss the features of the approach by computer simulations. In terms of our theoretical analyses, we improve the ring-circuit approach, based on the reflection ladder structure gratings, into a more suitable form based on transmission gratings, and we substitute the LCLVs with optoelectronic switches. Finally we give the experimental results of both the transmission grating and optoelectronic switches.

  14. Financial planning via multi-stage stochastic programs

    Energy Technology Data Exchange (ETDEWEB)

    Mulvey, J.

    1994-12-31

    This paper presents a framework for modeling financial applications, including asset allocation, as multi-stage stochastic programs. Starting with the classic single-period Markowitz model, we show that additional realistic issues can be addressed via multi-period stochastic programming. The advantages of integrating liabilities, assets, and investment goals are discussed. An investor must design a dynamic model for the stochastic parameters and link this process to an integrated asset-liability system if he wants to measure portfolio risk over time. Partial analysis leads to errors in risk evaluation. Algorithms for solving the resulting large-scale nonlinear stochastic programs are described. Topics for future research are proposed.

  15. Multistage Spectral Relaxation Method for Solving the Hyperchaotic Complex Systems

    Directory of Open Access Journals (Sweden)

    Hassan Saberi Nik

    2014-01-01

    Full Text Available We present a pseudospectral method application for solving the hyperchaotic complex systems. The proposed method, called the multistage spectral relaxation method (MSRM is based on a technique of extending Gauss-Seidel type relaxation ideas to systems of nonlinear differential equations and using the Chebyshev pseudospectral methods to solve the resulting system on a sequence of multiple intervals. In this new application, the MSRM is used to solve famous hyperchaotic complex systems such as hyperchaotic complex Lorenz system and the complex permanent magnet synchronous motor. We compare this approach to the Runge-Kutta based ode45 solver to show that the MSRM gives accurate results.

  16. Fundamentals of reliability engineering applications in multistage interconnection networks

    CERN Document Server

    Gunawan, Indra

    2014-01-01

    This book presents fundamentals of reliability engineering with its applications in evaluating reliability of multistage interconnection networks. In the first part of the book, it introduces the concept of reliability engineering, elements of probability theory, probability distributions, availability and data analysis.  The second part of the book provides an overview of parallel/distributed computing, network design considerations, and more.  The book covers a comprehensive reliability engineering methods and its practical aspects in the interconnection network systems. Students, engineers, researchers, managers will find this book as a valuable reference source.

  17. Thermochemical production of hydrogen via multistage water splitting processes

    Science.gov (United States)

    Funk, J. E.

    1975-01-01

    This paper presents and reviews the fundamental thermodynamic principles underlying thermochemical water splitting processes. The overall system is considered first and the temperature limitation in process thermal efficiency is developed. The relationship to an ideal water electrolysis cell is described and the nature of efficient multistage reaction processes is discussed. The importance of the reaction entropy change and the relation of the reaction free energy change to the work of separation is described. A procedure for analyzing thermochemical water splitting processes is presented and its use to calculate individual stage efficiency is demonstrated. A number of processes are used to illustrate the concepts and procedures.

  18. Improved Multistage Wiener Filters in Nonhomogeneous Clutter Environments

    Institute of Scientific and Technical Information of China (English)

    Bin Tang; Xue-Gang Wang; Ke-Song Chen

    2008-01-01

    A new method combining space-time preprocessing with multistage Wiener filters (STPMWF) is proposed to improve the performance of space-time adaptive processing (STAP) in nonhomogeneous clutter scenario. The new scheme only requires the data from the primary range bin, thus it can suppress discrete interferers efficiently, without calculating the inverse of covariance matrix. Comparing to the original MWF approach, the proposed scheme can be regarded as practical solutions for robust and effective STAP of nonhomogeneous radar data. The theoretical analysis shows that our STPMWF is simple in implementation and fast in convergence. The numeric results by using simulated data exhibit a good agreement with the proposed theory.

  19. Multi-Stage Convex Relaxation Methods for Machine Learning

    Science.gov (United States)

    2013-03-01

    relaxation with Lasso (L1 regularization), the multi-stage convex relaxation method can 3 Initialize v̂ = 1 Repeat the following two steps until convergence...observations using the following sparse regression method: ŵ = arg min w  1 n ‖Xw − y‖22 + λ d∑ j=1 g(|wj |)  , (9) where g(|wj |) is a...estimation problems. Statistical Science, 27:576–593, 2012. Tong Zhang. Some sharp performance bounds for least squares regression with L1

  20. Sequential maneuvering decisions based on multi-stage influence diagram in air combat

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A multi-stage influence diagram is used to model the pilot's sequential decision making in one on one air combat.The model based on the multi-stage influence diagram graphically describes the elements of decision process,and contains a point-mass model for the dynamics of an aircraft and takes into account the decision maker's Dreferences under uncertain conditions.Considering an active opponent,the opponent's maneuvers can be modeled stochastically.The solution of multistage influence diagram Can be obtained by converting the multistage influence diagram into a two-level optimization problem.The simulation results show the model is effective.

  1. Interaction of Salmonella enterica Serovar Typhimurium with Intestinal Organoids Derived from Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Forbester, Jessica L; Goulding, David; Vallier, Ludovic; Hannan, Nicholas; Hale, Christine; Pickard, Derek; Mukhopadhyay, Subhankar; Dougan, Gordon

    2015-07-01

    The intestinal mucosa forms the first line of defense against infections mediated by enteric pathogens such as salmonellae. Here we exploited intestinal "organoids" (iHOs) generated from human induced pluripotent stem cells (hIPSCs) to explore the interaction of Salmonella enterica serovar Typhimurium with iHOs. Imaging and RNA sequencing were used to analyze these interactions, and clear changes in transcriptional signatures were detected, including altered patterns of cytokine expression after the exposure of iHOs to bacteria. S. Typhimurium microinjected into the lumen of iHOs was able to invade the epithelial barrier, with many bacteria residing within Salmonella-containing vacuoles. An S. Typhimurium invA mutant defective in the Salmonella pathogenicity island 1 invasion apparatus was less capable of invading the iHO epithelium. Hence, we provide evidence that hIPSC-derived organoids are a promising model of the intestinal epithelium for assessing interactions with enteric pathogens.

  2. Current Multistage Drug Delivery Systems Based on the Tumor Microenvironment

    Science.gov (United States)

    Chen, Binlong; Dai, Wenbing; He, Bing; Zhang, Hua; Wang, Xueqing; Wang, Yiguang; Zhang, Qiang

    2017-01-01

    The development of traditional tumor-targeted drug delivery systems based on EPR effect and receptor-mediated endocytosis is very challenging probably because of the biological complexity of tumors as well as the limitations in the design of the functional nano-sized delivery systems. Recently, multistage drug delivery systems (Ms-DDS) triggered by various specific tumor microenvironment stimuli have emerged for tumor therapy and imaging. In response to the differences in the physiological blood circulation, tumor microenvironment, and intracellular environment, Ms-DDS can change their physicochemical properties (such as size, hydrophobicity, or zeta potential) to achieve deeper tumor penetration, enhanced cellular uptake, timely drug release, as well as effective endosomal escape. Based on these mechanisms, Ms-DDS could deliver maximum quantity of drugs to the therapeutic targets including tumor tissues, cells, and subcellular organelles and eventually exhibit the highest therapeutic efficacy. In this review, we expatiate on various responsive modes triggered by the tumor microenvironment stimuli, introduce recent advances in multistage nanoparticle systems, especially the multi-stimuli responsive delivery systems, and discuss their functions, effects, and prospects. PMID:28255348

  3. Multi-stage circulating fluidized bed syngas cooling

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Guan, Xiaofeng; Peng, WanWang

    2016-10-11

    A method and apparatus for cooling hot gas streams in the temperature range 800.degree. C. to 1600.degree. C. using multi-stage circulating fluid bed (CFB) coolers is disclosed. The invention relates to cooling the hot syngas from coal gasifiers in which the hot syngas entrains substances that foul, erode and corrode heat transfer surfaces upon contact in conventional coolers. The hot syngas is cooled by extracting and indirectly transferring heat to heat transfer surfaces with circulating inert solid particles in CFB syngas coolers. The CFB syngas coolers are staged to facilitate generation of steam at multiple conditions and hot boiler feed water that are necessary for power generation in an IGCC process. The multi-stage syngas cooler can include internally circulating fluid bed coolers, externally circulating fluid bed coolers and hybrid coolers that incorporate features of both internally and externally circulating fluid bed coolers. Higher process efficiencies can be realized as the invention can handle hot syngas from various types of gasifiers without the need for a less efficient precooling step.

  4. Numerical Simulation of Multi-Stage Turbomachinery Flows

    Science.gov (United States)

    Adamczyk, John J.; Hathaway, Michael D.; Shabbir, Aamir; Wellborn, Steven R.

    1999-01-01

    A comprehensive assessment is made of the predictive capability of the average passage flow model as applied to multi-stage axial flow compressors. The average passage flow model describes the time average flow field within a typical passage of a blade row embedded in a multi-stage configuration. In this work data taken within a four and one-half stage large low speed compressor will be used to assess the weakness and strengths of the predictive capabilities of the average passage flow model. The low speed compressor blading is of modern design and employs stators with end-bends. Measurements were made with slow and high response instrumentation. The high response measurements revealed the velocity components of both the rotor and stator wakes. Based on the measured wake profiles it will be argued that blade boundary layer transition is playing an important role in setting compressor performance. A model which mimics the effects of blade boundary layer transition within the frame work of the average passage model will be presented. Simulations which incorporated this model showed a dramatic improvement in agreement with data.

  5. A Quasi-One-Dimensional CFD Model for Multistage Turbomachines

    Institute of Scientific and Technical Information of China (English)

    Olivier Léonard; Olivier Adam

    2008-01-01

    The objective of this paper is to present a fast and reliable CFD model that is able to simulate stationary and transient operations of multistage compressors and turbines. This analysis tool is based on an adapted version of the Euler equations solved by a time-marching, finite-volume method. The Euler equations have been extended by including source terms expressing the blade-flow interactions. These source terms are determined using the velocity triangles and a row-by-row representation of the blading at mid-span. The losses and deviations undergone by the fluid across each blade row are supplied by correlations. The resulting flow solver is a performance prediction tool based only on the machine geometry, offering the possibility of exploring the entire characteristic map of a multistage compressor or turbine. Its efficiency in terms of CPU time makes it possible to couple it to an optimization algorithm or to a gas turbine performance tool. Different test-cases are presented for which the calculated characteristic maps are compared to experimental ones.

  6. Towards Multi-Stage Intrusion Detection using IP Flow Records

    Directory of Open Access Journals (Sweden)

    Muhammad Fahad Umer

    2016-10-01

    Full Text Available Traditional network-based intrusion detection sys-tems using deep packet inspection are not feasible for modern high-speed networks due to slow processing and inability to read encrypted packet content. As an alternative to packet-based intrusion detection, researchers have focused on flow-based intrusion detection techniques. Flow-based intrusion detection systems analyze IP flow records for attack detection. IP flow records contain summarized traffic information. However, flow data is very large in high-speed networks and cannot be processed in real-time by the intrusion detection system. In this paper, an efficient multi-stage model for intrusion detection using IP flows records is proposed. The first stage in the model classifies the traffic as normal or malicious. The malicious flows are further analyzed by a second stage. The second stage associates an attack type with malicious IP flows. The proposed multi-stage model is efficient because the majority of IP flows are discarded in the first stage and only malicious flows are examined in detail. We also describe the implementation of our model using machine learning techniques.

  7. Multi-stage apodized pupil Lyot coronagraph experimental results

    Science.gov (United States)

    Abe, L.; Venet, M.; Enya, K.; Kataza, H.; Nakagawa, T.; Tamura, M.

    2008-07-01

    Prolate (Pupil) Apodized Lyot Coronagraphs (PPALC) are known to offer optimal performances for a Lyot-type Coronagraph configuration, i.e. with an opaque occulting focal mask. One additional benefit of PPALC is its possible use in a multi-stage configuration. In theory, the coronagraphic performance can be QN, where Q is the energy rejection factor of one stage (the first one), and N the number of stages. Several ground-based telescopes are considering PPALC as an option for their high-contrast instrumentation (e.g. Gemini/GPI, EELT/EPICS, Subaru HiCIAO). Although the PPALC suffers from several limitations, several works are currently focused on fabricating entrance pupil apodizers and trying to find ways to overcome chromatism issues. In this work, we present the first experimental results from Multi-Stage PPALC (MS-PPALC) that was done in the context of the Japanese space telescope SPICA coronagraph project. Our entrance pupil apodizers use small diameter High Energy Beam Sensitive glass (HEBS-glass) from Canyon Materials Inc. The current results show modest coronagraphic performance due to uncompensated phase aberrations inherent to HEBS-glass material. In addition, and due to these uncompensated phase aberrations, the present optical configuration is an altered version of the originally planned set-up. However, we can demonstrate the validity the MS-PPALC concept and compare it to numerical simulations.

  8. Multistage Stochastic Programming and its Applications in Energy Systems Modeling and Optimization

    Science.gov (United States)

    Golari, Mehdi

    Electric energy constitutes one of the most crucial elements to almost every aspect of life of people. The modern electric power systems face several challenges such as efficiency, economics, sustainability, and reliability. Increase in electrical energy demand, distributed generations, integration of uncertain renewable energy resources, and demand side management are among the main underlying reasons of such growing complexity. Additionally, the elements of power systems are often vulnerable to failures because of many reasons, such as system limits, weak conditions, unexpected events, hidden failures, human errors, terrorist attacks, and natural disasters. One common factor complicating the operation of electrical power systems is the underlying uncertainties from the demands, supplies and failures of system components. Stochastic programming provides a mathematical framework for decision making under uncertainty. It enables a decision maker to incorporate some knowledge of the intrinsic uncertainty into the decision making process. In this dissertation, we focus on application of two-stage and multistage stochastic programming approaches to electric energy systems modeling and optimization. Particularly, we develop models and algorithms addressing the sustainability and reliability issues in power systems. First, we consider how to improve the reliability of power systems under severe failures or contingencies prone to cascading blackouts by so called islanding operations. We present a two-stage stochastic mixed-integer model to find optimal islanding operations as a powerful preventive action against cascading failures in case of extreme contingencies. Further, we study the properties of this problem and propose efficient solution methods to solve this problem for large-scale power systems. We present the numerical results showing the effectiveness of the model and investigate the performance of the solution methods. Next, we address the sustainability issue

  9. Research on Multi-Stage Inventory Model by Markov Decision Process

    Science.gov (United States)

    Rong, Ke

    This paper researched multi-stage inventory system and established limited inventory Markov model, on the other hand it induced DP algorithm of limited inventory Markov model. The results proved that the reorder point of multi-stage inventory system can guarantee demand, and also allows the storage costs to a minimum level in accordance with the above model.

  10. Principles of a novel multistage circulating fluidized bed reactor for biomass gasification

    NARCIS (Netherlands)

    Kersten, Sascha R.A.; Prins, Wolter; Drift, van der Bram; Swaaij, van Wim P.M.

    2003-01-01

    In this paper a novel multistage circulating fluidized bed reactor has been introduced. The riser of this multistage circulating fluidized bed consists of several segments (seven in the base-case design) in series each built-up out of two opposite cones. Due to the specific shape, a fluidized bed ar

  11. Multi-stage methodology to detect health insurance claim fraud.

    Science.gov (United States)

    Johnson, Marina Evrim; Nagarur, Nagen

    2016-09-01

    Healthcare costs in the US, as well as in other countries, increase rapidly due to demographic, economic, social, and legal changes. This increase in healthcare costs impacts both government and private health insurance systems. Fraudulent behaviors of healthcare providers and patients have become a serious burden to insurance systems by bringing unnecessary costs. Insurance companies thus develop methods to identify fraud. This paper proposes a new multistage methodology for insurance companies to detect fraud committed by providers and patients. The first three stages aim at detecting abnormalities among providers, services, and claim amounts. Stage four then integrates the information obtained in the previous three stages into an overall risk measure. Subsequently, a decision tree based method in stage five computes risk threshold values. The final decision stating whether the claim is fraudulent is made by comparing the risk value obtained in stage four with the risk threshold value from stage five. The research methodology performs well on real-world insurance data.

  12. Multistage CSR microbunching gain development in transport or recirculation arcs

    CERN Document Server

    Tsai, Cheng-Ying; Li, Rui; Tennant, Chris

    2015-01-01

    Coherent synchrotron radiation (CSR) induced microbunching instability has been one of the most challenging issues in the design of modern accelerators. A linear Vlasov solver has been developed [1] and applied to investigate the physical processes of microbunching gain amplification for several example lattices [2]. In this paper, by further extending the concept of stage gain as proposed by Huang and Kim [3], we develop a method to characterize the microbunching development in terms of stage orders that allow the quantitative comparison of optics impacts on microbunching gain for different lattices. We find that the microbunching instability in our demonstrated arcs has a distinguishing feature of multistage amplification (e.g, up to 6th stage amplification for our example transport arcs, in contrast to two-stage amplification for a typical 4-dipole bunch compressor chicane). We also try to connect lattice optics pattern with the obtained stage gain functions by a physical interpretation. This Vlasov analys...

  13. Multistage audiovisual integration of speech: dissociating identification and detection

    DEFF Research Database (Denmark)

    Eskelund, Kasper; Tuomainen, Jyrki; Andersen, Tobias

    2011-01-01

    Speech perception integrates auditory and visual information. This is evidenced by the McGurk illusion where seeing the talking face influences the auditory phonetic percept and by the audiovisual detection advantage where seeing the talking face influences the detectability of the acoustic speech...... signal. Here we show that identification of phonetic content and detection can be dissociated as speech-specific and non-specific audiovisual integration effects. To this end, we employed synthetically modified stimuli, sine wave speech (SWS), which is an impoverished speech signal that only observers...... informed of its speech-like nature recognize as speech. While the McGurk illusion only occurred for informed observers the audiovisual detection advantage occurred for naïve observers as well. This finding supports a multi-stage account of audiovisual integration of speech in which the many attributes...

  14. Extracting multistage screening rules from online dating activity data.

    Science.gov (United States)

    Bruch, Elizabeth; Feinberg, Fred; Lee, Kee Yeun

    2016-09-20

    This paper presents a statistical framework for harnessing online activity data to better understand how people make decisions. Building on insights from cognitive science and decision theory, we develop a discrete choice model that allows for exploratory behavior and multiple stages of decision making, with different rules enacted at each stage. Critically, the approach can identify if and when people invoke noncompensatory screeners that eliminate large swaths of alternatives from detailed consideration. The model is estimated using deidentified activity data on 1.1 million browsing and writing decisions observed on an online dating site. We find that mate seekers enact screeners ("deal breakers") that encode acceptability cutoffs. A nonparametric account of heterogeneity reveals that, even after controlling for a host of observable attributes, mate evaluation differs across decision stages as well as across identified groupings of men and women. Our statistical framework can be widely applied in analyzing large-scale data on multistage choices, which typify searches for "big ticket" items.

  15. Analysis of multi-stage open shop processing systems

    CERN Document Server

    Eggermont, Christian; Woeginger, Gerhard J

    2011-01-01

    We study algorithmic problems in multi-stage open shop processing systems that are centered around reachability and deadlock detection questions. We characterize safe and unsafe system states. We show that it is easy to recognize system states that can be reached from the initial state (where the system is empty), but that in general it is hard to decide whether one given system state is reachable from another given system state. We show that the problem of identifying reachable deadlock states is hard in general open shop systems, but is easy in the special case where no job needs processing on more than two machines (by linear programming and matching theory), and in the special case where all machines have capacity one (by graph-theoretic arguments).

  16. A Cost-Effective Architecture For Optical Multistage Interconnection Network

    Directory of Open Access Journals (Sweden)

    Mehrnaz Moudi

    2013-02-01

    Full Text Available In this paper a new architecture for Optical Multistage Interconnection Networks (OMINs has been proposed to avoid crosstalk problem. At the same time, the probablity of losing pass through an optical long connection path is reduced in this architecture. The new architecture is inherent form the standard OMIN by converting two switches of the network to one switch in each row. By reducing the number of switches in new architecture, the reduction in the execution time is considered. The modifying in the number of passes via the same low stage transformation is negligible. The ability of the new architecture to decrease cost and avoid crosstalk has been validated through simulations that show improvement in the network performance in terms of approximately 30% reduction in the execution time.

  17. Integrated quality control architecture for multistage machining processes

    Science.gov (United States)

    Yang, Jie; Liu, Guixiong

    2010-12-01

    To solve problems concerning the process quality prediction control for the multistage machining processes, a integrated quality control architecture is proposed in this paper. First, a hierarchical multiple criteria decision model is established for the key process and the weight matrix method stratified is discussed. Predictive control of the manufacturing quality is not just for on-site monitoring and control layer, control layer in the enterprise, remote monitoring level of quality exists a variety of target predictive control demand, therefore, based on XML to achieve a unified description of manufacturing quality information, and in different source of quality information between agencies to achieve the transfer and sharing. This will predict complex global quality control, analysis and diagnosis data to lay a good foundation to achieve a more practical, open and standardized manufacturing quality with higher levels of information integration system.

  18. Multistage Hybrid Arabic/Indian Numeral OCR System

    CERN Document Server

    Alginaih, Yasser M

    2010-01-01

    The use of OCR in postal services is not yet universal and there are still many countries that process mail sorting manually. Automated Arabic/Indian numeral Optical Character Recognition (OCR) systems for Postal services are being used in some countries, but still there are errors during the mail sorting process, thus causing a reduction in efficiency. The need to investigate fast and efficient recognition algorithms/systems is important so as to correctly read the postal codes from mail addresses and to eliminate any errors during the mail sorting stage. The objective of this study is to recognize printed numerical postal codes from mail addresses. The proposed system is a multistage hybrid system which consists of three different feature extraction methods, i.e., binary, zoning, and fuzzy features, and three different classifiers, i.e., Hamming Nets, Euclidean Distance, and Fuzzy Neural Network Classifiers. The proposed system, systematically compares the performance of each of these methods, and ensures t...

  19. Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Fleeter, S.; Lawless, P.B. [Purdue Univ., West Lafayette, IN (United States)

    1995-10-01

    The gas turbine has the potential for power production at the highest possible efficiency. The challenge is to ensure that gas turbines operate at the optimum efficiency so as to use the least fuel and produce minimum emissions. A key component to meeting this challenge is the turbine. Turbine performance, both aerodynamics and heat transfer, is one of the barrier advanced gas turbine development technologies. This is a result of the complex, highly three-dimensional and unsteady flow phenomena in the turbine. Improved turbine aerodynamic performance has been achieved with three-dimensional highly-loaded airfoil designs, accomplished utilizing Euler or Navier-Stokes Computational Fluid Dynamics (CFD) codes. These design codes consider steady flow through isolated blade rows. Thus they do not account for unsteady flow effects. However, unsteady flow effects have a significant impact on performance. Also, CFD codes predict the complete flow field. The experimental verification of these codes has traditionally been accomplished with point data - not corresponding plane field measurements. Thus, although advanced CFD predictions of the highly complex and three-dimensional turbine flow fields are available, corresponding data are not. To improve the design capability for high temperature turbines, a detailed understanding of the highly unsteady and three-dimensional flow through multi-stage turbines is necessary. Thus, unique data are required which quantify the unsteady three-dimensional flow through multi-stage turbine blade rows, including the effect of the film coolant flow. This requires experiments in appropriate research facilities in which complete flow field data, not only point measurements, are obtained and analyzed. Also, as design CFD codes do not account for unsteady flow effects, the next logical challenge and the current thrust in CFD code development is multiple-stage analyses that account for the interactions between neighboring blade rows.

  20. AERODYNAMIC AND BLADING DESIGN OF MULTISTAGE AXIAL FLOW COMPRESSORS

    Science.gov (United States)

    Crouse, J. E.

    1994-01-01

    The axial-flow compressor is used for aircraft engines because it has distinct configuration and performance advantages over other compressor types. However, good potential performance is not easily obtained. The designer must be able to model the actual flows well enough to adequately predict aerodynamic performance. This computer program has been developed for computing the aerodynamic design of a multistage axial-flow compressor and, if desired, the associated blading geometry input for internal flow analysis. The aerodynamic solution gives velocity diagrams on selected streamlines of revolution at the blade row edges. The program yields aerodynamic and blading design results that can be directly used by flow and mechanical analysis codes. Two such codes are TSONIC, a blade-to-blade channel flow analysis code (COSMIC program LEW-10977), and MERIDL, a more detailed hub-to-shroud flow analysis code (COSMIC program LEW-12966). The aerodynamic and blading design program can reduce the time and effort required to obtain acceptable multistage axial-flow compressor configurations by generating good initial solutions and by being compatible with available analysis codes. The aerodynamic solution assumes steady, axisymmetric flow so that the problem is reduced to solving the two-dimensional flow field in the meridional plane. The streamline curvature method is used for the iterative aerodynamic solution at stations outside of the blade rows. If a blade design is desired, the blade elements are defined and stacked within the aerodynamic solution iteration. The blade element inlet and outlet angles are established by empirical incidence and deviation angles to the relative flow angles of the velocity diagrams. The blade element centerline is composed of two segments tangentially joined at a transition point. The local blade angle variation of each element can be specified as a fourth-degree polynomial function of path distance. Blade element thickness can also be specified

  1. Liquid chromatography-mass spectrometry utilizing multi-stage fragmentation for the identification of oxysterols.

    Science.gov (United States)

    Karu, Kersti; Hornshaw, Martin; Woffendin, Gary; Bodin, Karl; Hamberg, Mats; Alvelius, Gunvor; Sjövall, Jan; Turton, John; Wang, Yuqin; Griffiths, William J

    2007-04-01

    In humans, the brain accounts for about 20% of the body's free cholesterol, most of which is synthesized de novo in brain. To maintain cholesterol balance throughout life, cholesterol becomes metabolized to 24S-hydroxycholesterol, principally in neurons. In mouse, rat, and probably human, metabolism to 24S-hydroxycholesterol accounts for about 50% of cholesterol turnover; however, the route by which the remainder is turned over has yet to be elucidated. Here, we describe a novel liquid chromatography (LC) multi-stage fragmentation mass spectrometry (MS(n)) methodology for the identification, with high sensitivity (low pg), of cholesterol metabolites in rat brain. The methodology includes derivatization to enhance ionization, exact mass analysis at high resolution to identify potential metabolites, and LC-MS(n) (n=3) to allow their characterization. 24S-hydroxycholesterol was confirmed as a major oxysterol in rat brain, and other oxysterols identified for the first time in brain included 24,25-, 24,27-, 25,27-, 6,24,- 7alpha,25-, and 7alpha,27-dihydroxycholesterols. In addition, 3beta-hydroxy-5-oxo-5,6-secocholestan-6-al and its aldol, two molecules linked to amyloidogenesis of proteins, were characterized in rat brain.

  2. Particle swarm optimization of ascent trajectories of multistage launch vehicles

    Science.gov (United States)

    Pontani, Mauro

    2014-02-01

    Multistage launch vehicles are commonly employed to place spacecraft and satellites in their operational orbits. If the rocket characteristics are specified, the optimization of its ascending trajectory consists of determining the optimal control law that leads to maximizing the final mass at orbit injection. The numerical solution of a similar problem is not trivial and has been pursued with different methods, for decades. This paper is concerned with an original approach based on the joint use of swarming theory and the necessary conditions for optimality. The particle swarm optimization technique represents a heuristic population-based optimization method inspired by the natural motion of bird flocks. Each individual (or particle) that composes the swarm corresponds to a solution of the problem and is associated with a position and a velocity vector. The formula for velocity updating is the core of the method and is composed of three terms with stochastic weights. As a result, the population migrates toward different regions of the search space taking advantage of the mechanism of information sharing that affects the overall swarm dynamics. At the end of the process the best particle is selected and corresponds to the optimal solution to the problem of interest. In this work the three-dimensional trajectory of the multistage rocket is assumed to be composed of four arcs: (i) first stage propulsion, (ii) second stage propulsion, (iii) coast arc (after release of the second stage), and (iv) third stage propulsion. The Euler-Lagrange equations and the Pontryagin minimum principle, in conjunction with the Weierstrass-Erdmann corner conditions, are employed to express the thrust angles as functions of the adjoint variables conjugate to the dynamics equations. The use of these analytical conditions coming from the calculus of variations leads to obtaining the overall rocket dynamics as a function of seven parameters only, namely the unknown values of the initial state

  3. Feet swelling in a multistage ultraendurance triathlete: a case study

    Directory of Open Access Journals (Sweden)

    Knechtle B

    2015-10-01

    Full Text Available Beat Knechtle,1 Matthias Alexander Zingg,2 Patrizia Knechtle,1 Thomas Rosemann,2 Christoph Alexander Rüst2 1Gesundheitszentrum St Gallen, St Gallen, 2Institute of Primary Care, University of Zurich, Zurich, Switzerland Abstract: Recent studies investigating ultraendurance athletes showed an association between excessive fluid intake and swelling of the lower limbs such as the feet. To date, this association has been investigated in single-stage ultraendurance races, but not in multistage ultraendurance races. In this case study, we investigated a potential association between fluid intake and feet swelling in a multistage ultraendurance race such as a Deca Iron ultratriathlon with ten Ironman triathlons within 10 consecutive days. A 49-year-old well-experienced ultratriathlete competed in autumn 2013 in the Deca Iron ultratriathlon held in Lonata del Garda, Italy, and finished the race as winner within 129:33 hours:minutes. Changes in body mass (including body fat and lean body mass, foot volume, total body water, and laboratory measurements were assessed. Food and fluid intake during rest and competing were recorded, and energy and fluid turnovers were estimated. During the ten stages, the volume of the feet increased, percentage body fat decreased, creatinine and urea levels increased, hematocrit and hemoglobin values decreased, and plasma [Na+] remained unchanged. The increase in foot volume was significantly and positively related to fluid intake during the stages. The poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. This case report shows that the volume of the foot increased during the ten stages, and the increase in volume was significantly and positively related to fluid intake during the stages. Furthermore, the poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. The continuous feet swelling during the race was

  4. Computer Adaptive Multistage Testing: Practical Issues, Challenges and Principles

    Directory of Open Access Journals (Sweden)

    Halil Ibrahim SARI

    2016-12-01

    Full Text Available The purpose of many test in the educational and psychological measurement is to measure test takers’ latent trait scores from responses given to a set of items. Over the years, this has been done by traditional methods (paper and pencil tests. However, compared to other test administration models (e.g., adaptive testing, traditional methods are extensively criticized in terms of producing low measurement accuracy and long test length. Adaptive testing has been proposed to overcome these problems. There are two popular adaptive testing approaches. These are computerized adaptive testing (CAT and computer adaptive multistage testing (ca-MST. The former is a well-known approach that has been predominantly used in this field. We believe that researchers and practitioners are fairly familiar with many aspects of CAT because it has more than a hundred years of history. However, the same thing is not true for the latter one. Since ca-MST is relatively new, many researchers are not familiar with features of it. The purpose of this study is to closely examine the characteristics of ca-MST, including its working principle, the adaptation procedure called the routing method, test assembly, and scoring, and provide an overview to researchers, with the aim of drawing researchers’ attention to ca-MST and encouraging them to contribute to the research in this area. The books, software and future work for ca-MST are also discussed.

  5. Fully Automated Operational Modal Analysis using multi-stage clustering

    Science.gov (United States)

    Neu, Eugen; Janser, Frank; Khatibi, Akbar A.; Orifici, Adrian C.

    2017-02-01

    The interest for robust automatic modal parameter extraction techniques has increased significantly over the last years, together with the rising demand for continuous health monitoring of critical infrastructure like bridges, buildings and wind turbine blades. In this study a novel, multi-stage clustering approach for Automated Operational Modal Analysis (AOMA) is introduced. In contrast to existing approaches, the procedure works without any user-provided thresholds, is applicable within large system order ranges, can be used with very small sensor numbers and does not place any limitations on the damping ratio or the complexity of the system under investigation. The approach works with any parametric system identification algorithm that uses the system order n as sole parameter. Here a data-driven Stochastic Subspace Identification (SSI) method is used. Measurements from a wind tunnel investigation with a composite cantilever equipped with Fiber Bragg Grating Sensors (FBGSs) and piezoelectric sensors are used to assess the performance of the algorithm with a highly damped structure and low signal to noise ratio conditions. The proposed method was able to identify all physical system modes in the investigated frequency range from over 1000 individual datasets using FBGSs under challenging signal to noise ratio conditions and under better signal conditions but from only two sensors.

  6. Multistage optical smoke detection approach for smoke alarm systems

    Science.gov (United States)

    Nguyen, Truc Kim Thi; Kim, Jong-Myon

    2013-05-01

    We propose a novel multistage smoke detection algorithm based on inherent optical characteristics such as diffusion, color, and texture of smoke. Moving regions in a video frame are detected by an approximate median background subtraction method using the diffusion behavior of smoke. These moving regions are segmented by a fuzzy C-means (FCM) clustering algorithm that uses the hue and saturation components of moving pixels in the hue-saturation-intensity color space. A decision rule is used to select candidate smoke regions from smoke-colored FCM clusters. An object tracking approach is employed in the candidate smoke region to detect candidate smoke objects in the video frame, and image texture parameters are extracted from these objects using a gray level co-occurrence matrix (GLCM). The thirteen GLCM features are selected to constitute the feature vector by applying principal components analysis, resulting in high-accuracy smoke detection. Finally, a back propagation neural network is utilized as a classifier to discriminate smoke and nonsmoke using the selected feature vector. Experimental results using a standard experimental dataset of video clips demonstrate that the proposed approach outperforms state-of-the-art smoke detection approaches in terms of accuracy, making real-life implementation feasible.

  7. Dynamics of Multistage Gear Transmission with Effects of Gearbox Vibrations

    Science.gov (United States)

    Choy, F. K.; Tu, Y. K.; Zakrajsek, J. J.; Townsend, Dennis P.

    1990-01-01

    A comprehensive approach is presented in analyzing the dynamic behavior of multistage gear transmission systems with the effects of gearbox induced vibrations and mass imbalances of the rotor. The modal method, with undamped frequencies and planar mode shapes, is used to reduce the degrees of freedom of the gear system for time-transient dynamic analysis. Both the lateral and torsional vibration modes of each rotor-bearing-gear stage as well as the interstage vibrational characteristics are coupled together through localized gear mesh tooth interactions. In addition, gearbox vibrations are also coupled to the rotor-bearing-gear system dynamics through bearing support forces between the rotor and the gearbox. Transient and steady state dynamics of lateral and torsional vibrations of the geared system are examined in both time and frequency domains to develop interpretations of the overall modal dynamic characteristics under various operating conditions. A typical three-stage geared system is used as an example. Effects of mass imbalance and gearbox vibrations on the system dynamic behavior are presented in terms of modal excitation functions for both lateral and torsional vibrations. Operational characteristics and conclusions are drawn from the results presented.

  8. Synthetic Multiple-Imputation Procedure for Multistage Complex Samples

    Directory of Open Access Journals (Sweden)

    Zhou Hanzhi

    2016-03-01

    Full Text Available Multiple imputation (MI is commonly used when item-level missing data are present. However, MI requires that survey design information be built into the imputation models. For multistage stratified clustered designs, this requires dummy variables to represent strata as well as primary sampling units (PSUs nested within each stratum in the imputation model. Such a modeling strategy is not only operationally burdensome but also inferentially inefficient when there are many strata in the sample design. Complexity only increases when sampling weights need to be modeled. This article develops a generalpurpose analytic strategy for population inference from complex sample designs with item-level missingness. In a simulation study, the proposed procedures demonstrate efficient estimation and good coverage properties. We also consider an application to accommodate missing body mass index (BMI data in the analysis of BMI percentiles using National Health and Nutrition Examination Survey (NHANES III data. We argue that the proposed methods offer an easy-to-implement solution to problems that are not well-handled by current MI techniques. Note that, while the proposed method borrows from the MI framework to develop its inferential methods, it is not designed as an alternative strategy to release multiply imputed datasets for complex sample design data, but rather as an analytic strategy in and of itself.

  9. Multi-stage FE simulation of hot ring rolling

    Science.gov (United States)

    Wang, C.; Geijselaers, H. J. M.; van den Boogaard, A. H.

    2013-05-01

    As a unique and important member of the metal forming family, ring rolling provides a cost effective process route to manufacture seamless rings. Applications of ring rolling cover a wide range of products in aerospace, automotive and civil engineering industries [1]. Above the recrystallization temperature of the material, hot ring rolling begins with the upsetting of the billet cut from raw stock. Next a punch pierces the hot upset billet to form a hole through the billet. This billet, referred to as preform, is then rolled by the ring rolling mill. For an accurate simulation of hot ring rolling, it is crucial to include the deformations, stresses and strains from the upsetting and piercing process as initial conditions for the rolling stage. In this work, multi-stage FE simulations of hot ring rolling process were performed by mapping the local deformation state of the workpiece from one step to the next one. The simulations of upsetting and piercing stages were carried out by 2D axisymmetric models using adaptive remeshing and element erosion. The workpiece for the ring rolling stage was subsequently obtained after performing a 2D to 3D mapping. The commercial FE package LS-DYNA was used for the study and user defined subroutines were implemented to complete the control algorithm. The simulation results were analyzed and also compared with those from the single-stage FE model of hot ring rolling.

  10. A cascaded three-phase symmetrical multistage voltage multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Shahid [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Singh, G K [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Besar, R [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Muhammad, G [Faculty of Information Science and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia)

    2006-10-15

    A cascaded three-phase symmetrical multistage Cockcroft-Walton voltage multiplier (CW-VM) is proposed in this report. It consists of three single-phase symmetrical voltage multipliers, which are connected in series at their smoothing columns like string of batteries and are driven by three-phase ac power source. The smoothing column of each voltage multiplier is charged twice every cycle independently by respective oscillating columns and discharged in series through load. The charging discharging process completes six times a cycle and therefore the output voltage ripple's frequency is of sixth order of the drive signal frequency. Thus the proposed approach eliminates the first five harmonic components of load generated voltage ripples and sixth harmonic is the major ripple component. The proposed cascaded three-phase symmetrical voltage multiplier has less than half the voltage ripple, and three times larger output voltage and output power than the conventional single-phase symmetrical CW-VM. Experimental and simulation results of the laboratory prototype are given to show the feasibility of proposed cascaded three-phase symmetrical CW-VM.

  11. Discontinuous Transition of a Multistage Independent Cascade Model on Networks

    CERN Document Server

    Hasegawa, Takehisa

    2012-01-01

    We study a multistage independent cascade (MIC) model in complex networks. This model is parameterized by two probabilities: T1 is the probability that a node adopting a fad increases the awareness of a neighboring susceptible node until it abandons the fad, and T2 is the probability that an adopter directly causes a susceptible node to adopt the fad. We formulate a framework of tree approximation for the MIC model on an uncorrelated network with an arbitrary given degree distribution. As an application, we study this model on a random regular network with degree k=6 to show that it has a rich phase diagram including continuous and discontinuous transition lines for the percolation of fads as well as a continuous transition line for the percolation of susceptible nodes. In particular, the percolation transition of fads is discontinuous (continuous) when T1 is larger (smaller) than a certain value. Furthermore, the phase boundaries drastically change by assigning a finite fraction of initial adopters. We discu...

  12. Optimization of organic Rankine cycle power systems considering multistage axial turbine design

    DEFF Research Database (Denmark)

    Meroni, Andrea; Andreasen, Jesper Graa; Persico, Giacomo

    2017-01-01

    Organic Rankine cycle power systems represent a viable and efficient solution for the exploitation of medium-to-low temperature heat sources. Despite the large number of commissioned units, there is limited literature on the design and optimization of organic Rankine cycle power systems considering...... multistage turbine design. This work presents a preliminary design methodology and working fluid selection for organic Rankine cycle units featuring multistage axial turbines. The method is then applied to the case of waste heat recovery from a large marine diesel engine. A multistage axial turbine model...... is presented and validated with the best available data from literature. The methodology allows the identification of the most suitable working fluid considering the trade-off between cycle and multistage turbine designs. The results of the optimization of cycle and turbine suggest that the fluid n...

  13. 4 Kelvin Cooling with Innovative Final Stage of Multistage Cryocooler Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Proposed for development is a proof-of-concept prototype for the final stage of a multistage cryocooler. This final stage comprises a high frequency pulse tube cold...

  14. Optimisation of the Low-Frequency Response of a Multi-stage Bioelectric Amplifier for Electrocardiogram (ECG Recording

    Directory of Open Access Journals (Sweden)

    Burke Martin J.

    2016-01-01

    Full Text Available This paper reports the optimisation of the low-frequency response of a multi-stage bioelectric amplifier intended for use in the measurement of the human electrocardiogram (ECG using high-impedance un-gelled electrodes. The frequency response was optimised to meet international performance requirements for electrocardiographic recorders, in particular the International Electrotechnical Commission 60601 standards [1,2]. The pole and zero locations of a multi-stage amplifier configuration were optimised to meet both time and frequency domain specifications. The optimum assignment for a three stage amplifier, having two differential stages and a differential-to-single-ended conversion stage was established by evaluating the performance of a number of circuit configurations. The optimum configuration was found to be two differential stages with a gain of 20dB each and a differential-to single-ended output stage with unity gain. The -3dB pole is placed at 0.028Hz and a zero at 0.0028Hz in the first and second stages to give an overall -3dB bandwidth of 0.043Hz. In addition, the pole of the input ac coupling network was placed at 0.0028Hz in order to meet the undershoot and recovery slope requirements in the narrow pulse response.

  15. Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

    OpenAIRE

    Zhanghua Lian; Ying Zhang; Xu Zhao; Shidong Ding; Tiejun Lin

    2015-01-01

    Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, ...

  16. FINITE ELEMENT SIMULATION AND OPTIMIZATION OF MULTISTAGE WARM/HOT FORMING FOR OUTER RACE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A multistage warm/hot forming is simulated for the cross grove outer race of constant velocity joint, using athermo-mechanical coupled rigid viscoplastic finite element method, and specially some problem for process develop-ment and die design are analyzed. A forming test shows that computed results have good agreement with experimentalresults. Above obtained results can be applied to development of multistage warm/hot forming process and die designfor outer race.

  17. Modelling and Control of the Multi-stage Cable Pulley-driven Flexible-joint Robot

    OpenAIRE

    Phongsaen Pitakwatchara

    2014-01-01

    This work is concerned with the task space impedance control of a robot driven through a multi-stage nonlinear flexible transmission system. Specifically, a two degrees-of-freedom cable pulley-driven flexible-joint robot is considered. Realistic modelling of the system is developed within the bond graph modelling framework. The model captures the nonlinear compliance behaviour of the multi-stage cable pulley transmission system, the spring effect of the augmented counterbalancing mechanism, t...

  18. Multi-Stage Recognition of Speech Emotion Using Sequential Forward Feature Selection

    Directory of Open Access Journals (Sweden)

    Liogienė Tatjana

    2016-07-01

    Full Text Available The intensive research of speech emotion recognition introduced a huge collection of speech emotion features. Large feature sets complicate the speech emotion recognition task. Among various feature selection and transformation techniques for one-stage classification, multiple classifier systems were proposed. The main idea of multiple classifiers is to arrange the emotion classification process in stages. Besides parallel and serial cases, the hierarchical arrangement of multi-stage classification is most widely used for speech emotion recognition. In this paper, we present a sequential-forward-feature-selection-based multi-stage classification scheme. The Sequential Forward Selection (SFS and Sequential Floating Forward Selection (SFFS techniques were employed for every stage of the multi-stage classification scheme. Experimental testing of the proposed scheme was performed using the German and Lithuanian emotional speech datasets. Sequential-feature-selection-based multi-stage classification outperformed the single-stage scheme by 12–42 % for different emotion sets. The multi-stage scheme has shown higher robustness to the growth of emotion set. The decrease in recognition rate with the increase in emotion set for multi-stage scheme was lower by 10–20 % in comparison with the single-stage case. Differences in SFS and SFFS employment for feature selection were negligible.

  19. "Miniguts" from plucked human hair meet Crohn's disease.

    Science.gov (United States)

    Hohwieler, M; Renz, S; Liebau, S; Lin, Q; Lechel, A; Klaus, J; Perkhofer, L; Zenke, M; Seufferlein, T; Illing, A; Müller, M; Kleger, A

    2016-08-01

    Human pluripotent stem cells represent a powerful tool to study human embryonic development and disease but also open up novel strategies for cell replacement therapies. Their capacity to give rise to every cell type of the human body, meanwhile, enables researchers to generate high yields of mesodermal, ectodermal, but also endodermal-derived tissues such as hepatic, pancreatic, or intestinal cells. Another progress in the field came with the advent of 3-dimensional culture conditions, so-called organoids, which facilitate maturation of stem cells and in turn more faithfully recapitulate human tissue architecture. While several studies reported the derivation of organoid cultures from adult intestinal tissue, the derivation of intestinal organoids derived from plucked human hair of Crohn's disease patients has not been reported. The current research project reports such successful generation and characterization of induced pluripotent stem cells (iPSCs) derived from hair sheet keratinocyte cultures of a patient with Crohn's disease. Stepwise differentiation along the intestinal lineage showed no differences in intermediate stages such as definitive endoderm formation. We also directed the patterned primitive gut tube toward intestinal organoids resembling the cellular architecture of human "miniguts". As expected from current pathophysiological knowledge on Crohn's disease, there were no obvious morphological differences in the "miniguts" derived from healthy control and diseased patient-induced pluripotent stem cells. Taken together, our platform will enable for detailed and complementary phenotyping of the pathophysiology of Crohn's disease in a novel disease-in-a-dish format.

  20. A Multi-stage Method to Extract Road from High Resolution Satellite Image

    Science.gov (United States)

    Zhijian, Huang; Zhang, Jinfang; Xu, Fanjiang

    2014-03-01

    Extracting road information from high-resolution satellite images is complex and hardly achieves by exploiting only one or two modules. This paper presents a multi-stage method, consisting of automatic information extraction and semi-automatic post-processing. The Multi-scale Enhancement algorithm enlarges the contrast of human-made structures with the background. The Statistical Region Merging segments images into regions, whose skeletons are extracted and pruned according to geometry shape information. Setting the start and the end skeleton points, the shortest skeleton path is constructed as a road centre line. The Bidirectional Adaptive Smoothing technique smoothens the road centre line and adjusts it to right position. With the smoothed line and its average width, a Buffer algorithm reconstructs the road region easily. Seen from the last results, the proposed method eliminates redundant non-road regions, repairs incomplete occlusions, jumps over complete occlusions, and reserves accurate road centre lines and neat road regions. During the whole process, only a few interactions are needed.

  1. Multistage vector delivery of sulindac and silymarin for prevention of colon cancer.

    Science.gov (United States)

    Scavo, Maria Principia; Gentile, Emanuela; Wolfram, Joy; Gu, Jianhua; Barone, Michele; Evangelopoulos, Michael; Martinez, Jonathan O; Liu, Xuewu; Celia, Christian; Tasciotti, Ennio; Vilar, Eduardo; Shen, Haifa

    2015-12-01

    Familial adenomatous polyposis (FAP) is an inherited condition secondary to germline mutations in the APC gene, thus resulting in the formation of hundreds of colonic adenomas that eventually progress into colon cancer. Surgical removal of the colon remains the only treatment option to avoid malignancy, as long-term exposure to chemopreventive agents such as sulindac (a non-steroidal anti-inflammatory drug) and silymarin (phytoestrogen) is not feasible. Here, we have developed a multistage silicon-based drug delivery platform for sulindac and silymarin that preferentially interacts with colon cancer cells as opposed to normal intestinal mucosa. Preferential binding and internalization of these drugs into colon cancer cells was obtained using a targeting strategy against the protein meprin A, which we demonstrate is overexpressed in human colon cancer cells and in the small intestine of Apc(Min/+) mice. We propose that this delivery system could potentially be used to reduce drug-induced side effects in FAP patients, thus enabling long-term prevention of adenoma formation.

  2. Lymphoma diagnosis in histopathology using a multi-stage visual learning approach

    Science.gov (United States)

    Codella, Noel; Moradi, Mehdi; Matasar, Matt; Sveda-Mahmood, Tanveer; Smith, John R.

    2016-03-01

    This work evaluates the performance of a multi-stage image enhancement, segmentation, and classification approach for lymphoma recognition in hematoxylin and eosin (H and E) stained histopathology slides of excised human lymph node tissue. In the first stage, the original histology slide undergoes various image enhancement and segmentation operations, creating an additional 5 images for every slide. These new images emphasize unique aspects of the original slide, including dominant staining, staining segmentations, non-cellular groupings, and cellular groupings. For the resulting 6 total images, a collection of visual features are extracted from 3 different spatial configurations. Visual features include the first fully connected layer (4096 dimensions) of the Caffe convolutional neural network trained from ImageNet data. In total, over 200 resultant visual descriptors are extracted for each slide. Non-linear SVMs are trained over each of the over 200 descriptors, which are then input to a forward stepwise ensemble selection that optimizes a late fusion sum of logistically normalized model outputs using local hill climbing. The approach is evaluated on a public NIH dataset containing 374 images representing 3 lymphoma conditions: chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), and mantle cell lymphoma (MCL). Results demonstrate a 38.4% reduction in residual error over the current state-of-art on this dataset.

  3. Induced pluripotent stem cells (iPSCs derived from cerebrotendinous xanthomatosis (CTX patient's fibroblasts carrying a R395S mutation

    Directory of Open Access Journals (Sweden)

    Philip Höflinger

    2016-09-01

    Full Text Available Induced pluripotent stem cells (iPSCs were generated from dermal fibroblasts from a 60-year-old cerebrotendinous xanthomatosis (CTX patient, carrying a homozygous mutation c. [1183C>A]; p. R395S in CYP27A1. Episomal plasmids encoding the pluripotency genes OCT4, SOX2, KLF4, L-MYC and LIN28 were introduced via electroporation. The generated line iPS-CTX-R395S has no sign of plasmid integration or chromosomal aberration and retained the mutation site in CYP27A1. Furthermore, iPSCs express pluripotency markers and are able to differentiate in all germ layers in vitro. The generated line may be a useful tool for disease modelling of CTX.

  4. Methods for in vitro functional analysis of iPSC derived cardiomyocytes - Special focus on analyzing the mechanical beating behavior.

    Science.gov (United States)

    Laurila, Eeva; Ahola, Antti; Hyttinen, Jari; Aalto-Setälä, Katriina

    2016-07-01

    A rapidly increasing number of papers describing novel iPSC models for cardiac diseases are being published. To be able to understand the disease mechanisms in more detail, we should also take the full advantage of the various methods for analyzing these cell models. The traditionally and commonly used electrophysiological analysis methods have been recently accompanied by novel approaches for analyzing the mechanical beatingbehavior of the cardiomyocytes. In this review, we provide first a concise overview on the methodology for cardiomyocyte functional analysis and then concentrate on the video microscopy, which provides a promise for a new faster yet reliable method for cardiomyocyte functional analysis. We also show how analysis conditions may affect the results. Development of the methodology not only serves the basic research on the disease models, but could also provide the much needed efficient early phase screening method for cardiac safety toxicology. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

  5. Chlorin e6 Functionalized Theranostic Multistage Nanovectors Transported by Stem Cells for Effective Photodynamic Therapy.

    Science.gov (United States)

    Näkki, Simo; Martinez, Jonathan O; Evangelopoulos, Michael; Xu, Wujun; Lehto, Vesa-Pekka; Tasciotti, Ennio

    2017-07-19

    Approaches to achieve site-specific and targeted delivery that provide an effective solution to reduce adverse, off target side effects are urgently needed for cancer therapy. Here, we utilized a Trojan-horse-like strategy to carry photosensitizer Chlorin e6 conjugated porous silicon multistage nanovectors with tumor homing mesenchymal stem cells for targeted photodynamic therapy and diagnosis. The inherent versatility of multistage nanovectors permitted the conjugation of photosensitizers to enable precise cell death induction (60%) upon photodynamic therapy, while simultaneously retaining the loading capacity to load various payloads, such as antitumor drugs and diagnostic nanoparticles. Furthermore, the mesenchymal stem cells that internalized the multistage nanovectors conserved their proliferation patterns and in vitro affinity to migrate and infiltrate breast cancer cells. In vivo administration of the mesenchymal stem cells carrying photosensitizer-conjugated multistage nanovectors in mice bearing a primary breast tumor confirmed their tropism toward cancer sites exhibiting similar targeting kinetics to control cells. In addition, this approach yielded in a > 70% decrease in local tumor cell viability after in vivo photodynamic therapy. In summary, these results show the proof-of-concept of how photosensitizer conjugated multistage nanovectors transported by stem cells can target tumors and be used for effective site-specific cancer therapy while potentially minimizing potential negative side effects.

  6. Adaptation of Decoy Fusion Strategy for Existing Multi-Stage Search Workflows

    Science.gov (United States)

    Ivanov, Mark V.; Levitsky, Lev I.; Gorshkov, Mikhail V.

    2016-09-01

    A number of proteomic database search engines implement multi-stage strategies aiming at increasing the sensitivity of proteome analysis. These approaches often employ a subset of the original database for the secondary stage of analysis. However, if target-decoy approach (TDA) is used for false discovery rate (FDR) estimation, the multi-stage strategies may violate the underlying assumption of TDA that false matches are distributed uniformly across the target and decoy databases. This violation occurs if the numbers of target and decoy proteins selected for the second search are not equal. Here, we propose a method of decoy database generation based on the previously reported decoy fusion strategy. This method allows unbiased TDA-based FDR estimation in multi-stage searches and can be easily integrated into existing workflows utilizing popular search engines and post-search algorithms.

  7. Bayesian synthetic evaluation of multistage reliability growth with instant and delayed fix modes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the multistage reliability growth tests with instant and delayed fix modes, the failure data can be assumed to follow Weibull processes with different parameters at different stages. For the Weibull process within a stage, by the proper selection of prior distribution form and the parameters, a concise posterior distribution form is obtained, thus simplifying the Bayesian analysis. In the multistage tests, the improvement factor is used to convert the posterior of one stage to the prior of the subsequent stage. The conversion criterion is carefully analyzed to determine the distribution parameters of the subsequent stage's variable reasonably. Based on the mentioned results, a new synthetic Bayesian evaluation program and algorithm framework is put forward to evaluate the multistage reliability growth tests with instant and delayed fix modes. The example shows the effectiveness and flexibility of this method.

  8. An Inventory-Theory-Based Inexact Multistage Stochastic Programming Model for Water Resources Management

    Directory of Open Access Journals (Sweden)

    M. Q. Suo

    2013-01-01

    Full Text Available An inventory-theory-based inexact multistage stochastic programming (IB-IMSP method is developed for planning water resources systems under uncertainty. The IB-IMSP is based on inexact multistage stochastic programming and inventory theory. The IB-IMSP cannot only effectively handle system uncertainties represented as probability density functions and discrete intervals but also efficiently reflect dynamic features of system conditions under different flow levels within a multistage context. Moreover, it can provide reasonable transferring schemes (i.e., the amount and batch of transferring as well as the corresponding transferring period associated with various flow scenarios for solving water shortage problems. The applicability of the proposed IB-IMSP is demonstrated by a case study of planning water resources management. The solutions obtained are helpful for decision makers in not only identifying different transferring schemes when the promised water is not met, but also making decisions of water allocation associated with different economic objectives.

  9. An Enhanced Genetic Algorithm to Solve the Static and Multistage Transmission Network Expansion Planning

    Directory of Open Access Journals (Sweden)

    Luis A. Gallego

    2012-01-01

    Full Text Available An enhanced genetic algorithm (EGA is applied to solve the long-term transmission expansion planning (LTTEP problem. The following characteristics of the proposed EGA to solve the static and multistage LTTEP problem are presented, (1 generation of an initial population using fast, efficient heuristic algorithms, (2 better implementation of the local improvement phase and (3 efficient solution of linear programming problems (LPs. Critical comparative analysis is made between the proposed genetic algorithm and traditional genetic algorithms. Results using some known systems show that the proposed EGA presented higher efficiency in solving the static and multistage LTTEP problem, solving a smaller number of linear programming problems to find the optimal solutions and thus finding a better solution to the multistage LTTEP problem.

  10. Simulation of three-dimensional viscous flow within a multistage turbine

    Science.gov (United States)

    Adamczyk, John J.; Celestina, Mark L.; Beach, Tim A.; Barnett, Mark

    1989-01-01

    This work outlines a procedure for simulating the flow field within multistage turbomachinery which includes the effects of unsteadiness, compressibility, and viscosity. The associated modeling equations are the average passage equation system which governs the time-averaged flow field within a typical passage of a blade row embedded within a multistage configuration. The results from a simulation of a low aspect ratio stage and a one-half turbine will be presented and compared with experimental measurements. It will be shown that the secondary flow field generated by the rotor causes the aerodynamic performance of the downstream vane to be significantly different from that of an isolated blade row.

  11. Simulation of 3-D viscous flow within a multi-stage turbine

    Science.gov (United States)

    Adamczyk, John J.; Celestina, Mark L.; Beach, Tim A.; Barnett, Mark

    1989-01-01

    This work outlines a procedure for simulating the flow field within multistage turbomachinery which includes the effects of unsteadiness, compressibility, and viscosity. The associated modeling equations are the average passage equation system which governs the time-averaged flow field within a typical passage of a blade row embedded within a multistage configuration. The results from a simulation of a low aspect ratio stage and a one-half turbine will be presented and compared with experimental measurements. It will be shown that the secondary flow field generated by the rotor causes the aerodynamic performance of the downstream vane to be significantly different from that of an isolated blade row.

  12. Effectiveness of multi-stage scrubbers in reducing emissions of air pollutants from pig houses

    OpenAIRE

    Zhao, Y.; Aarnink, A.J.A.; Jong, de, P.; Ogink, N. W. M.; Groot Koerkamp, P.W.G.

    2011-01-01

    Emissions of air pollutants from livestock houses may raise environmental problems and pose hazards to public health. They can be reduced by scrubbers installed at the air outlets of livestock houses. In this study, three multi-stage scrubbers were evaluated in terms of their effectiveness in reducing emissions of airborne dust, total bacteria, ammonia, and CO2 from pig houses in winter. The three multi-stage scrubbers were one double-stage scrubber (acid stage+ bio-filter), one double-stage ...

  13. Continuous-data diagnostic tests for paratuberculosis as a multistage disease

    DEFF Research Database (Denmark)

    Toft, Nils; Nielsen, Søren Saxmose; Jørgensen, Erik

    2005-01-01

    We devised a general method for interpretation of multistage diseases using continuous-data diagnostic tests. As an example, we used paratuberculosis as a multistage infection with 2 stages of infection as well as a noninfected state. Using data from a Danish research project, a fecal culture...... testing scheme was linked to an indirect ELISA and adjusted for covariates (parity, age at first calving, and days in milk). We used the log-transformed optical densities in a Bayesian network to obtain the probabilities for each of the 3 infection stages for a given optical density (adjusted...

  14. Maisotsenko cycle applications in multi-stage ejector recycling module for chemical production

    Science.gov (United States)

    Levchenko, D. O.; Artyukhov, A. E.; Yurko, I. V.

    2017-08-01

    The article is devoted to the theoretical bases of multistage (multi-level) utilization modules as part of chemical plants (on the example of the technological line for obtaining nitrogen fertilizers). The possibility of recycling production waste (ammonia vapors, dust and substandard nitrogen fertilizers) using ejection devices and waste heat using Maisotsenko cycle technology (Maisotsenko heat and mass exchanger (HMX), Maisotsenko power cycles and recuperators, etc.) is substantiated. The principle of operation of studied recycling module and prospects for its implementation are presented. An improved technological scheme for obtaining granular fertilizers and granules with porous structure with multistage (multi-level) recycling module is proposed.

  15. Thickness distribution of multi-stage incremental forming with different forming stages and angle intervals

    Institute of Scientific and Technical Information of China (English)

    李军超; 杨芬芬; 周志强

    2015-01-01

    Although multi-stage incremental sheet forming has always been adopted instead of single-stage forming to form parts with a steep wall angle or to achieve a high forming performance, it is largely dependent on empirical designs. In order to research multi-stage forming further, the effect of forming stages (n) and angle interval between the two adjacent stages (Δα) on thickness distribution was investigated. Firstly, a finite element method (FEM) model of multi-stage incremental forming was established and experimentally verified. Then, based on the proposed simulation model, different strategies were adopted to form a frustum of cone with wall angle of 30° to research the thickness distribution of multi-pass forming. It is proved that the minimum thickness increases largely and the variance of sheet thickness decreases significantly as the value of n grows. Further, with the increase of Δα, the minimum thickness increases initially and then decreases, and the optimal thickness distribution is achieved with Δα of 10°. Additionally, a formula is deduced to estimate the sheet thickness after multi-stage forming and proved to be effective. And the simulation results fit well with the experimental results.

  16. Nonlinear model predictive control of a multistage evaporator system using recurrent neural networks

    NARCIS (Netherlands)

    Atuonwu, J.C.; Cao, Y.; Rangaiah, G.P.; Tade, M.O.

    2011-01-01

    The use of multistage evaporators, motivated by the energy economy from reusing the flashed steam is common in a wide range of process industries. Such evaporators however present several control problems which manifest in the form of strong interactions among the many process variables, significant

  17. Multistage Effort and the Equity Structure of Venture Investment Based on Reciprocity Motivation

    Directory of Open Access Journals (Sweden)

    Chuan Ding

    2015-01-01

    Full Text Available For venture capitals, it is a long process from an entry to its exit. In this paper, the activity of venture investment will be divided into multistages. And, according to the effort level entrepreneurs will choose, the venture capitalists will provide an equity structure at the very beginning. As a benchmark for comparison, we will establish two game models on multistage investment under perfect rationality: a cooperative game model and a noncooperative one. Further, as a cause of pervasive psychological preference behavior, reciprocity motivation will influence the behavior of the decision-makers. Given this situation, Rabin’s reciprocity motivation theory will be applied to the multistage game model of the venture investment, and multistage behavior game model will be established as well, based on the reciprocity motivation. By looking into the theoretical derivations and simulation studies, we find that if venture capitalists and entrepreneurs both have reciprocity preferences, their utility would have been Pareto improvement compared with those under perfect rationality.

  18. Understanding, accepting and controlling risks: A multistage framework for risk communication

    NARCIS (Netherlands)

    Vlek, C.A.J.

    1995-01-01

    The meanings and functions of cc risk communication a (RC, for shea) are specified on the basis of a multistage framework for handling societal risks. After identifying various reasons for RC, essential components of > are briefly discussed : basic risk communicator positions, different levels of ri

  19. UNDERSTANDING, ACCEPTING AND CONTROLLING RISKS - A MULTISTAGE FRAMEWORK FOR RISK COMMUNICATION

    NARCIS (Netherlands)

    VLEK, CAJ

    1995-01-01

    The meanings and functions of cc risk communication a (RC, for shea) are specified on the basis of a multistage framework for handling societal risks. After identifying various reasons for RC, essential components of > are briefly discussed : basic risk communicator positions, different levels of ri

  20. Turbulence and Complex Flow Phenomena in Multi-Stage Axial Turbomachines

    Science.gov (United States)

    2007-05-10

    J.J., Mulac R.A., Celestina M.L., 1986, "A Model for Closing the Inviscid Form of the Average-Passage Equation System," ASME Paper No. 86-GT-227...Adamczyk J.J.; Celestina M.L.; Beach T.A.; Barnett M., 1990, "Simulation Of Three Dimensional Viscous Flow Within A Multistage Turbine," J. of

  1. Seven prostate cancer susceptibility loci identified by a multi-stage genome-wide association study

    DEFF Research Database (Denmark)

    Kote-Jarai, Zsofia; Olama, Ali Amin Al; Giles, Graham G

    2011-01-01

    Prostate cancer (PrCa) is the most frequently diagnosed male cancer in developed countries. We conducted a multi-stage genome-wide association study for PrCa and previously reported the results of the first two stages, which identified 16 PrCa susceptibility loci. We report here the results of st...

  2. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    NARCIS (Netherlands)

    Sanchez, L.D.; Marin, L.M.; Visscher, J.T.; Rietveld, L.C.

    2012-01-01

    This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF) in a multi-stage filtration (MSF) plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It s

  3. TwinGrid: A wafer post-processed multistage Micro Patterned Gaseous Detector

    NARCIS (Netherlands)

    Bilevych, Y.; Blanco Carballo, V.M.; Chefdeville, M.; Fransen, M.; van der Graaf, H.; Salm, C.; Schmitz, J.; Timmermans, J.

    2009-01-01

    This paper presents a new multistage Micro Patterned Gaseous Detector (MPGD) made by wafer post-processing. The device consists of a double metal grid supported by SU-8 structures on top of a Timepix chip. The detector has been operated with He/iC(4)H(10) and Ar/iC(4)H(10) gas mixtures. Cosmic rays

  4. Twingrid: a wafer post-processed multistage micro patterned gaseous detector

    NARCIS (Netherlands)

    Bilevych, Y.; Blanco Carballo, V.M.; Chefdeville, M.A.; Fransen, M.; Graaf, van der H.; Salm, C.; Schmitz, J.; Timmermans, J.

    2009-01-01

    This paper presents a new multistage Micro Patterned Gaseous Detector (MPGD) made by wafer post-processing. The device consists of a double metal grid supported by SU-8 structures on top of a Timepix chip. The detector has been operated with He/iC4H10 and Ar/iC4H10 gas mixtures. Cosmic rays as well

  5. Multi-stage decoding for multi-level block modulation codes

    Science.gov (United States)

    Lin, Shu

    1991-01-01

    In this paper, we investigate various types of multi-stage decoding for multi-level block modulation codes, in which the decoding of a component code at each stage can be either soft-decision or hard-decision, maximum likelihood or bounded-distance. Error performance of codes is analyzed for a memoryless additive channel based on various types of multi-stage decoding, and upper bounds on the probability of an incorrect decoding are derived. Based on our study and computation results, we find that, if component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. In particular, we find that the difference in performance between the suboptimum multi-stage soft-decision maximum likelihood decoding of a modulation code and the single-stage optimum decoding of the overall code is very small: only a fraction of dB loss in SNR at the probability of an incorrect decoding for a block of 10(exp -6). Multi-stage decoding of multi-level modulation codes really offers a way to achieve the best of three worlds, bandwidth efficiency, coding gain, and decoding complexity.

  6. Axial liquid mixing in a gas-liquid Multi-Stage Agitated Contactor (MAC)

    NARCIS (Netherlands)

    Breman, B.B; Beenackers, A.A C M; Bouma, M.J; VanderWerf, M.H.

    1996-01-01

    Data on interstage liquid mixing are reported for a gas-liquid Multi-stage Agitated Contactor (MAC). A dynamic method using heat as a tracer was applied for water, n-octane and monoethylene glycol as liquids both with and without the presence of a dispersed gas phase (air). In all cases, the axial m

  7. Multi-stage kernel-based conditional quantile prediction in time series

    NARCIS (Netherlands)

    de Gooijer, J.G.; Gannoun, A.; Zerom Godefay, D.

    2001-01-01

    We present a multi-stage conditional quantile predictor for time series of Markovian structure. It is proved that at any quantile level p \\in (0,1), the asymptotic mean squared error (MSE) of the new predictor is smaller than the single-stage conditional quantile predictor. A simulation study

  8. Reducing drying energy consumption by adsorbent property optimization in multistage systems

    NARCIS (Netherlands)

    Atuonwu, J.C.; Straten, G. van; Deventer, H.C. van; Boxtel, A.J.B. van

    2012-01-01

    This work presents a mixed integer nonlinear programming method for the design of energy efficient multistage adsorption dryers within product temperature and moisture constraints. The aim is to find the adsorbent type and properties that minimize specific energy consumption. The results show that t

  9. Metabolite Identification Using Automated Comparison of High-Resolution Multistage Mass Spectral Trees

    NARCIS (Netherlands)

    Rojas-Cherto, M.; Peironcely, J.E.; Kasper, P.T.; Hooft, van der J.J.J.; Vos, de R.C.H.; Vreeken, R.; Hankemeier, T.; Reijmers, T.

    2012-01-01

    Multistage mass spectrometry (MSn) generating so-called spectral trees is a powerful tool in the annotation and structural elucidation of metabolites and is increasingly used in the area of accurate mass LC/MS-based metabolomics to identify unknown, but biologically relevant, compounds. As a consequ

  10. Approximate queueing models for capacitated multi-stage inventory systems under base-stock control

    NARCIS (Netherlands)

    Avsar, Zeynep Müge; Zijm, Willem H.M.

    2014-01-01

    A queueing analysis is presented for base-stock controlled multi-stage production-inventory systems with capacity constraints. The exact queueing model is approximated by replacing some state-dependent conditional probabilities (that are used to express the transition rates) by constants. Two

  11. Interaction between Gaming and Multistage Guiding Strategies on Students' Field Trip Mobile Learning Performance and Motivation

    Science.gov (United States)

    Chen, Chih-Hung; Liu, Guan-Zhi; Hwang, Gwo-Jen

    2016-01-01

    In this study, an integrated gaming and multistage guiding approach was proposed for conducting in-field mobile learning activities. A mobile learning system was developed based on the proposed approach. To investigate the interaction between the gaming and guiding strategies on students' learning performance and motivation, a 2 × 2 experiment was…

  12. Understanding, accepting and controlling risks: A multistage framework for risk communication

    NARCIS (Netherlands)

    Vlek, C.A.J.

    1995-01-01

    The meanings and functions of cc risk communication a (RC, for shea) are specified on the basis of a multistage framework for handling societal risks. After identifying various reasons for RC, essential components of > are briefly discussed : basic risk communicator positions, different levels of

  13. Seven prostate cancer susceptibility loci identified by a multi-stage genome-wide association study

    DEFF Research Database (Denmark)

    Kote-Jarai, Zsofia; Olama, Ali Amin Al; Giles, Graham G

    2011-01-01

    Prostate cancer (PrCa) is the most frequently diagnosed male cancer in developed countries. We conducted a multi-stage genome-wide association study for PrCa and previously reported the results of the first two stages, which identified 16 PrCa susceptibility loci. We report here the results of st...

  14. Effectiveness of multi-stage scrubbers in reducing emissions of air pollutants from pig houses

    NARCIS (Netherlands)

    Zhao, Y.; Aarnink, A.J.A.; Jong, de M.C.M.; Ogink, N.W.M.; Groot Koerkamp, P.W.G.

    2011-01-01

    Emissions of air pollutants from livestock houses may raise environmental problems and pose hazards to public health. They can be reduced by scrubbers installed at the air outlets of livestock houses. In this study, three multi-stage scrubbers were evaluated in terms of their effectiveness in reduci

  15. Bayesian Analysis for Linearized Multi-Stage Models in Quantal Bioassay.

    Science.gov (United States)

    Kuo, Lynn; Cohen, Michael P.

    Bayesian methods for estimating dose response curves in quantal bioassay are studied. A linearized multi-stage model is assumed for the shape of the curves. A Gibbs sampling approach with data augmentation is employed to compute the Bayes estimates. In addition, estimation of the "relative additional risk" and the "risk specific…

  16. Interaction between Gaming and Multistage Guiding Strategies on Students' Field Trip Mobile Learning Performance and Motivation

    Science.gov (United States)

    Chen, Chih-Hung; Liu, Guan-Zhi; Hwang, Gwo-Jen

    2016-01-01

    In this study, an integrated gaming and multistage guiding approach was proposed for conducting in-field mobile learning activities. A mobile learning system was developed based on the proposed approach. To investigate the interaction between the gaming and guiding strategies on students' learning performance and motivation, a 2 × 2 experiment was…

  17. Multi-stage kernel-based conditional quantile prediction in time series

    NARCIS (Netherlands)

    de Gooijer, J.G.; Gannoun, A.; Zerom Godefay, D.

    2001-01-01

    We present a multi-stage conditional quantile predictor for time series of Markovian structure. It is proved that at any quantile level p \\in (0,1), the asymptotic mean squared error (MSE) of the new predictor is smaller than the single-stage conditional quantile predictor. A simulation study confir

  18. A Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success

    Science.gov (United States)

    Luong, Ming; Stevens, Jeff

    2015-01-01

    The Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success, a theoretical stages-of-growth model, explains long-term success in IT outsourcing relationships. Research showed the IT outsourcing relationship life cycle consists of four distinct, sequential stages: contract, transition, support, and partnership. The model was…

  19. Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

    Directory of Open Access Journals (Sweden)

    Zhanghua Lian

    2015-03-01

    Full Text Available Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, open differential-pressure sliding sleeve, and open ball-injection sliding sleeve under a hold-down packer. Moreover, mathematical models were respectively built for the above three cases. According to the Lame formula and Von Mises stress calculation formula for the thick-walled cylinder in the theory of elastic mechanics, a mathematical model was also established to calculate the equivalent stress for tubing string safety evaluation when the fracturing string was under the combined action of inner pressure, external squeezing force and axial stress, and another mathematical model was built for the mechanical strength and safety evaluation of multi-stage fracturing strings. In addition, a practical software was developed for the mechanical safety evaluation of horizontal well multi-stage fracturing strings according to the mathematical model developed for the mechanical calculation of the multi-packer string in horizontal wells. The research results were applied and verified in a gas well of Tahe Oilfield in the Tarim Basin with excellent effects, providing a theoretical basis and a simple and reliable technical means for optimal design and safety evaluation of safe operational parameters of multi-stage fracturing strings in horizontal wells.

  20. A single or multistage mycobacterium avium subsp. paratuberculosis subunit vaccine

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention provides one or more immunogenic polypeptides for use in a preventive or therapeutic vaccine against latent or active infection in a human or animal caused by a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis. Furthermore a single or multi-phase vaccine...... comprising the one or more immunogenic polypeptides is provided for administration for the prevention or treatment of infection with a Mycobacterium species, e.g. Mycobacterium avium subsp. paratuberculosis. Additionally, nucleic acid vaccines, capable of in vivo expression of the multi-phase vaccine...

  1. The effect of tooling deformation on process control in multistage metal forming

    Science.gov (United States)

    Havinga, Jos; van den Boogaard, Ton

    2016-10-01

    Forming of high-strength steels leads to high loads within the production process. In multistage metal forming, the loads in different process stages are transferred to the other stages through elastic deformation of the stamping press. This leads to interactions between process steps, affecting the process forces in each stage and the final geometry of the product. When force measurements are used for control of the metal forming process, it is important to understand these interactions. In his work, interactions within an industrial multistage forming process are investigated. Cutting, deepdrawing, forging and bending steps are performed in the production process. Several test runs of a few thousand products each were performed to gather information about the process. Statistical methods are used to analyze the measurements. Based on the cross-correlation between the force measurements of different stages, it can be shown that the interactions between the process steps are caused by elastic deformation of the tooling and the stamping press.

  2. Fibre Bragg Grating as a Multi-Stage Structure Health Monitoring Sensor

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira

    2016-01-01

    There is a clear need to implement models and measurement systems through the entire life of the wind turbine blade. In this chapter will be presented some work conducted to implement optical fibres as a multi-stage sensor, capable to measure different structural properties, and link them with all...... involving crack growth and fibre Bragg sensing is described that highlights the response from the fibre optic which will correctly detect the presence and growth of damage. Models to implement these results in a damage detection system for a wind turbine blade can then be developed....... the different life stages and support a better design of the wind turbine blades. The characteristics and functionality of fibre Bragg grating sensors are briefly introduced. Their application as multi-stage structure health monitoring sensors for polymer laminate composite is then described...

  3. Minimizing the Switch and Link Conflicts in an Optical Multi-stage Interconnection Network

    CERN Document Server

    Bhardwaj, Ved Prakash; Tyagi, Vipin

    2012-01-01

    Multistage Interconnection Networks (MINs) are very popular in switching and communication applications. A MIN connects N inputs to N outputs and is referred as an N \\times N MIN; having size N. Optical Multistage Interconnection Network (OMIN) represents an important class of Interconnection networks. Crosstalk is the basic problem of OMIN. Switch Conflict and Link Conflict are the two main reason of crosstalk. In this paper, we are considering both problems. A number of techniques like Optical window, Improved Window, Heuristic, Genetic, and Zero have been proposed earlier in this research domain. In this paper, we have proposed two algorithms called Address Selection Algorithm and Route Selection Algorithm (RSA). RSA is based on Improved Window Method. We have applied the proposed algorithms on existing Omega network, having shuffle-exchange connection pattern. The main functionality of ASA and RSA is to minimize the number of switch and link conflicts in the network and to provide conflict free routes.

  4. The effect of hot multistage drawing on molecular structure and optical properties of polyethylene terephthalate fibers

    Directory of Open Access Journals (Sweden)

    Aminoddin Haji

    2012-08-01

    Full Text Available In this work, mechanical and structural parameters related to the optical properties of polyethylene terephthalate (PET fibers drawn at hot multistage have been investigated. The changes in optical parameters upon changing draw ratio are used to obtain the mechanical orientation factors and , various orientation functions f2(θ, f4(θ and f6(θ, and amorphous and crystalline orientation functions (f a and f c. Also, the numbers of random links between the network junction points (N1, the average optical orientation (Fav, and the distribution function of segment ω(cos θ were calculated. In addition, an empirical formula was suggested to correlate changes in the birefringence with the draw ratio and its constants were determined. The study demonstrated change on the molecular orientation functions and structural parameters upon hot multistage drawing. Significant variations in the characteristic properties of the drawn PET fibers were due to reorientation of the molecules caused by applied heat and external tension.

  5. Comparative study of multistage cemented liner and openhole system completion technologies in the Montney resource play

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Brad; Lui, David; Klim, James [Murphy Oil Company Ltd (United States); Kenyon, Mike [Society of Petroleum Engineers (Canada); McCaffrey, Matt [Packers Plus Energy Services (Canada)

    2011-07-01

    This work highlights hydraulic fracturing technologies implemented in the Lower Montney formation. The goal of the study is to compare two multistage hydraulic fracturing techniques: the cemented liner and the open hole multistage system (OHMS) and to investigate the effects each has on production rates and performance in general. The overall field was separated into two geographical areas and a total of 15 wells were investigated, some of which were subjected to cemented liner fracturing and others to OHMS. Various physical, mechanical, and financial data were collected. These data included: oil production rates, well spacing, pumping rates, stage times, and operational costs. In general, it was shown that OHMS proved to be the more suitable fracturing technique for the Montney formation, yielding higher initial and cumulative production rates. Moreover, average fracturing costs per stage were lower and time to complete was less than with the cemented liner technique.

  6. Limitations Of The Current State Space Modelling Approach In Multistage Machining Processes Due To Operation Variations

    Science.gov (United States)

    Abellán-Nebot, J. V.; Liu, J.; Romero, F.

    2009-11-01

    The State Space modelling approach has been recently proposed as an engineering-driven technique for part quality prediction in Multistage Machining Processes (MMP). Current State Space models incorporate fixture and datum variations in the multi-stage variation propagation, without explicitly considering common operation variations such as machine-tool thermal distortions, cutting-tool wear, cutting-tool deflections, etc. This paper shows the limitations of the current State Space model through an experimental case study where the effect of the spindle thermal expansion, cutting-tool flank wear and locator errors are introduced. The paper also discusses the extension of the current State Space model to include operation variations and its potential benefits.

  7. Minimizing the Switch and Link Conflicts in an Optical Multi-stage Interconnection Network

    Directory of Open Access Journals (Sweden)

    Ved Prakash Bhardwaj

    2011-07-01

    Full Text Available Multistage Interconnection Networks (MINs are very popular in switching and communication applications. A MIN connects N inputs to N outputs and is referred as an N andamp;times; N MIN; having size N. Optical Multistage Interconnection Network (OMIN represents an important class of Interconnection networks. Crosstalk is the basic problem of OMIN. Switch Conflict and Link Conflict are the two main reason of crosstalk. In this paper, we are considering both problems. A number of techniques like Optical window, Improved Window, Heuristic, Genetic, and Zero have been proposed earlier in this research domain. In this paper, we have proposed two algorithms called Address Selection Algorithm and Route Selection Algorithm (RSA. RSA is based on Improved Window Method. We have applied the proposed algorithms on existing Omega network, having shuffleexchange connection pattern. The main functionality of ASA and RSA is to minimize the number of switch and link conflicts in the network and to provide conflict free routes.

  8. Multi-stage high order semi-Lagrangian schemes for incompressible flows in Cartesian geometries

    CERN Document Server

    Cameron, Alexandre; Dormy, Emmanuel

    2016-01-01

    Efficient transport algorithms are essential to the numerical resolution of incompressible fluid flow problems. Semi-Lagrangian methods are widely used in grid based methods to achieve this aim. The accuracy of the interpolation strategy then determines the properties of the scheme. We introduce a simple multi-stage procedure which can easily be used to increase the order of accuracy of a code based on multi-linear interpolations. This approach is an extension of a corrective algorithm introduced by Dupont \\& Liu (2003, 2007). This multi-stage procedure can be easily implemented in existing parallel codes using a domain decomposition strategy, as the communications pattern is identical to that of the multi-linear scheme. We show how a combination of a forward and backward error correction can provide a third-order accurate scheme, thus significantly reducing diffusive effects while retaining a non-dispersive leading error term.

  9. Fractional Multistage Hydrothermal Liquefaction of Biomass and Catalytic Conversion into Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cortright, Randy; Rozmiarek, Robert; Dally, Brice; Holland, Chris

    2017-08-31

    The objective of this project was to develop an improved multistage process for the hydrothermal liquefaction (HTL) of biomass to serve as a new front-end, deconstruction process ideally suited to feed Virent’s well-proven catalytic technology, which is already being scaled up. This process produced water soluble, partially de-oxygenated intermediates that are ideally suited for catalytic finishing to fungible distillate hydrocarbons. Through this project, Virent, with its partners, demonstrated the conversion of pine wood chips to drop-in hydrocarbon distillate fuels using a multi-stage fractional conversion system that is integrated with Virent’s BioForming® process. The majority of work was in the liquefaction task and included temperature scoping, solvent optimization, and separations.

  10. A Multi-Stage Optimization Model With Minimum Energy Consumption-Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    S. Krishnakumar

    2012-09-01

    Full Text Available Optimization models related with routing, bandwidth utilization and power consumption are developed in the wireless mesh computing environment using the operations research techniques such as maximal flow model, transshipment model and minimax optimizing algorithm. The Path creation algorithm is used to find the multiple paths from source to destination.A multi-stage optimization model is developed by combining the multi-path optimization model, optimization model in capacity utilization and energy optimization model and minimax optimizing algorithm. The input to the multi-stage optimization model is a network with many source and destination. The optimal solution obtained from this model is a minimum energy consuming path from source to destination along with the maximum data rate over each link. The performance is evaluated by comparing the data rate values of superimposed algorithm and minimax optimizing algorithm. The main advantage of this model is the reduction of traffic congestion in the network.

  11. Multistage Random Growing Small-World Networks with Power-Law Degree Distribution

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Guo; DANG Yan-Zhong; WANG Zhong-Tuo

    2006-01-01

    @@ We present a simple rule which could generate scale-free networks with very large clustering coefficient and very small average distance. These networks, called the multistage random growing networks (MRGNs), are constructed by a two-stage adding process for each new node. The analytic results of the power-law exponentγ = 3 and the clustering coefficient C = 0.81 are obtained, which agree with the simulation results approximately.

  12. A multistage volumetric bar chart chip for visualized quantification of DNA

    OpenAIRE

    Song, Yujun; Wang, Yuanchen; Qin, Lidong

    2013-01-01

    Nucleic acid detection is critical in disease diagnosis as well as in the environmental assays of harmful bacteria or viruses and forensic applications. Current methods for visualized quantification of DNA require costly and sophisticated instruments. Here, we report a multistage propelled volumetric bar chart chip (MV-Chip) for multiplexing and quantitative detection of DNA. Owing to its ‘rocket-like’ propelling reaction, the pre-deposited platinum films could perform cascade amplification a...

  13. Fast Multicast on Multistage Interconnection Networks Using Multi-Head Worms

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaodong; XU Ming; ZHOU Xingming

    1999-01-01

    Abstract This paper proposes a new approach forimplementing fast multicast on multistage interconnection networks (MINs)with multi-head worms. For an MIN with n stages of k×k switches,a singlemulti-head worm can cover an arbitrary set of destinations with asingle communication start-up. Compared with schemes using unicastmessages, this approach reduces multicast latency significantly andperforms better than multi-destination worms.

  14. Multi-stage selective catalytic reduction of NOx in lean burn engine exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Penetrante, B.M.; Hsaio, M.C.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States)

    1997-12-31

    Many studies suggest that the conversion of NO to NO{sub 2} is an important intermediate step in the selective catalytic reduction (SCR) of NO{sub x} to N{sub 2}. Some effort has been devoted to separating the oxidative and reductive functions of the catalyst in a multi-stage system. This method works fine for systems that require hydrocarbon addition. The hydrocarbon has to be injected between the NO oxidation catalyst and the NO{sub 2} reduction catalyst; otherwise, the first-stage oxidation catalyst will also oxidize the hydrocarbon and decrease its effectiveness as a reductant. The multi-stage catalytic scheme is appropriate for diesel engine exhausts since they contain insufficient hydrocarbons for SCR, and the hydrocarbons can be added at the desired location. For lean-burn gasoline engine exhausts, the hydrocarbons already present in the exhausts will make it necessary to find an oxidation catalyst that can oxidize NO to NO{sub 2} but not oxidize the hydrocarbon. A plasma can also be used to oxidize NO to NO{sub 2}. Plasma oxidation has several advantages over catalytic oxidation. Plasma-assisted catalysis can work well for both diesel engine and lean-burn gasoline engine exhausts. This is because the plasma can oxidize NO in the presence of hydrocarbons without degrading the effectiveness of the hydrocarbon as a reductant for SCR. In the plasma, the hydrocarbon enhances the oxidation of NO, minimizes the electrical energy requirement, and prevents the oxidation of SO{sub 2}. This paper discusses the use of multi-stage systems for selective catalytic reduction of NO{sub x}. The multi-stage catalytic scheme is compared to the plasma-assisted catalytic scheme.

  15. MULTISTAGE ADAPTIVE HIGHER-ORDER NONLINEAR FINITE IMPULSE RESPONSE FILTERS FOR CHAOTIC TIME SERIES PREDICTIONS

    Institute of Scientific and Technical Information of China (English)

    ZHANG JIA-SHU; XIAO XIAN-CI

    2001-01-01

    A multistage adaptive higher-order nonlinear finite impulse response (MAHONFIR) filter is proposed to predict chaotic time series. Using this approach, we may readily derive the decoupled parallel algorithm for the adaptation of the coefficients of the MAHONFIR filter, to guarantee a more rapid convergence of the adaptive weights to their optimal values. Numerical simulation results show that the MAHONFIR filters proposed here illustrate a very good performance for making an adaptive prediction of chaotic time series.

  16. Use of a multistage model to predict time trends in smoking induced lung cancer.

    OpenAIRE

    Swartz, J B

    1992-01-01

    STUDY OBJECTIVE--The aims were to use a mathematical model to predict the time course of smoking induced lung cancer, and to investigate to what extent the most recent increases in lung cancer mortality are due to cigarette smoking. DESIGN--A mathematical model was developed and solved by simulation to construct detailed smoking histories of the US white male population given available prevalence data by age and cohort. A multistage carcinogenesis model was used to predict the time course of ...

  17. A multistage differential transformation method for approximate solution of Hantavirus infection model

    Science.gov (United States)

    Gökdoğan, Ahmet; Merdan, Mehmet; Yildirim, Ahmet

    2012-01-01

    The goal of this study is presented a reliable algorithm based on the standard differential transformation method (DTM), which is called the multi-stage differential transformation method (MsDTM) for solving Hantavirus infection model. The results obtanied by using MsDTM are compared to those obtained by using the Runge-Kutta method (R-K-method). The proposed technique is a hopeful tool to solving for a long time intervals in this kind of systems.

  18. Dantzig-Wolfe Decomposition for Solving Multistage Stochastic Capacity-Planning Problems

    OpenAIRE

    Singh, Kavinesh J.; Andy B. Philpott; Wood, Kevin

    2009-01-01

    Operations Research, 57, pp. 1271-1286. We describe a multistage, stochastic, mixed-integer programming model for planning capacity expansion of production facilities. A scenario tree represents uncertainty in the mode; a general mixed-integer program defines the operation submodel at each scenario-tree mode, and capacity expansion decisions link the stages. We apply "variable splitting" to two model variants, and solve those variants using Dantzig-Wolfe decomposition. The Dantzig-Wolf ...

  19. Efficiency increase in ship's primal energy system using a multistage compression with intercooling

    Directory of Open Access Journals (Sweden)

    Landeka Petar

    2016-01-01

    Full Text Available This paper focuses on an analysis of the potential increase of efficiency in ship's primal energy system using a turbocharger with multistage compression with intercooling, and diverting a greater flow of exhaust gases to power turbine of waste heat recovery system (WHR. Analysis of potential efficiency increase has been made for various stages of compression for a 100 % main engine load, and an analysis of five stage compression with intercooling for a main engine load between 50% and 100%.

  20. Generation, purification and transplantation of photoreceptors derived from human induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Deepak A Lamba

    Full Text Available BACKGROUND: Inherited and acquired retinal degenerations are frequent causes of visual impairment and photoreceptor cell replacement therapy may restore visual function to these individuals. To provide a source of new retinal neurons for cell based therapies, we developed methods to derive retinal progenitors from human ES cells. METHODOLOGY/PHYSICAL FINDINGS: In this report we have used a similar method to direct induced pluripotent stem cells (iPS from human fibroblasts to a retinal progenitor fate, competent to generate photoreceptors. We also found we could purify the photoreceptors derived from the iPS cells using fluorescence activated cell sorting (FACS after labeling photoreceptors with a lentivirus driving GFP from the IRBP cis-regulatory sequences. Moreover, we found that when we transplanted the FACS purified iPSC derived photoreceptors, they were able to integrate into a normal mouse retina and express photoreceptor markers. CONCLUSIONS: This report provides evidence that enriched populations of human photoreceptors can be derived from iPS cells.

  1. Generation of induced pluripotent stem cells from human nasal epithelial cells using a Sendai virus vector.

    Directory of Open Access Journals (Sweden)

    Mizuho Ono

    Full Text Available The generation of induced pluripotent stem cells (iPSCs by introducing reprogramming factors into somatic cells is a promising method for stem cell therapy in regenerative medicine. Therefore, it is desirable to develop a minimally invasive simple method to create iPSCs. In this study, we generated human nasal epithelial cells (HNECs-derived iPSCs by gene transduction with Sendai virus (SeV vectors. HNECs can be obtained from subjects in a noninvasive manner, without anesthesia or biopsy. In addition, SeV carries no risk of altering the host genome, which provides an additional level of safety during generation of human iPSCs. The multiplicity of SeV infection ranged from 3 to 4, and the reprogramming efficiency of HNECs was 0.08-0.10%. iPSCs derived from HNECs had global gene expression profiles and epigenetic states consistent with those of human embryonic stem cells. The ease with which HNECs can be obtained, together with their robust reprogramming characteristics, will provide opportunities to investigate disease pathogenesis and molecular mechanisms in vitro, using cells with particular genotypes.

  2. Generation of Induced Pluripotent Stem Cells from Human Nasal Epithelial Cells Using a Sendai Virus Vector

    Science.gov (United States)

    Ono, Mizuho; Hamada, Yuko; Horiuchi, Yasue; Matsuo-Takasaki, Mami; Imoto, Yoshimasa; Satomi, Kaishi; Arinami, Tadao; Hasegawa, Mamoru; Fujioka, Tsuyoshi; Nakamura, Yukio; Noguchi, Emiko

    2012-01-01

    The generation of induced pluripotent stem cells (iPSCs) by introducing reprogramming factors into somatic cells is a promising method for stem cell therapy in regenerative medicine. Therefore, it is desirable to develop a minimally invasive simple method to create iPSCs. In this study, we generated human nasal epithelial cells (HNECs)-derived iPSCs by gene transduction with Sendai virus (SeV) vectors. HNECs can be obtained from subjects in a noninvasive manner, without anesthesia or biopsy. In addition, SeV carries no risk of altering the host genome, which provides an additional level of safety during generation of human iPSCs. The multiplicity of SeV infection ranged from 3 to 4, and the reprogramming efficiency of HNECs was 0.08–0.10%. iPSCs derived from HNECs had global gene expression profiles and epigenetic states consistent with those of human embryonic stem cells. The ease with which HNECs can be obtained, together with their robust reprogramming characteristics, will provide opportunities to investigate disease pathogenesis and molecular mechanisms in vitro, using cells with particular genotypes. PMID:22912751

  3. Neural Network Learning for Principal Component Analysis: A Multistage Decomposition Approach

    Institute of Scientific and Technical Information of China (English)

    FENGDazheng; ZHANGXianda; BAOZheng

    2004-01-01

    This paper presents a novel neural network model for finding the principal components of an Ndimensional data stream. This neural network consists of r (≤N) neurons, where the i-th neuron has only N - i+1 weights and an N- i+1 dimensional input vector, while each neuron in most of the relative classical neural networks includes N weights and an N dimensional input vector. All the neurons are trained by the NIC algorithm under the single component case[7] so as to get a series of dimension-reducing principal components in which the dimension number of the i-th principal component is N- i+1. In multistage dimension-reducing processing, the weight vector of i-th neuron is always orthogonal to the subspace constructed from the weight vectors of the first i-1 neurons. By systematic reconstruction technique, wecan recover all the principal components from a series of dimension-reducing ones. Its remarkable advantage is that its computational efficiency of the neural network learning based on the Novel information criterion (NIC) is improved and the weight storage is reduced, by the multistage dimension-reducing processing (multistage decomposition)for the covariance matrix or the input vector sequence. In addition, we study several important properties of the NIC learning algorithm.

  4. Application of multi-stage Monte Carlo method for solving machining optimization problems

    Directory of Open Access Journals (Sweden)

    Miloš Madić

    2014-08-01

    Full Text Available Enhancing the overall machining performance implies optimization of machining processes, i.e. determination of optimal machining parameters combination. Optimization of machining processes is an active field of research where different optimization methods are being used to determine an optimal combination of different machining parameters. In this paper, multi-stage Monte Carlo (MC method was employed to determine optimal combinations of machining parameters for six machining processes, i.e. drilling, turning, turn-milling, abrasive waterjet machining, electrochemical discharge machining and electrochemical micromachining. Optimization solutions obtained by using multi-stage MC method were compared with the optimization solutions of past researchers obtained by using meta-heuristic optimization methods, e.g. genetic algorithm, simulated annealing algorithm, artificial bee colony algorithm and teaching learning based optimization algorithm. The obtained results prove the applicability and suitability of the multi-stage MC method for solving machining optimization problems with up to four independent variables. Specific features, merits and drawbacks of the MC method were also discussed.

  5. A Simple and Unified Model for Spanwise Mixing in Multistage Axial Flow COmpressors

    Institute of Scientific and Technical Information of China (English)

    S.-M.Li; M.-Z.Chen

    1992-01-01

    A basic equation system for meridional throughflow fileds in multistage axial flow compressors has been deduced,containing many unknown correlation terms,which describe different kinds of spanwise mixing mechanism in a unified form.The equation system shows that spanwise mixing of meridional flows in compressors is attributed to three kinds of mechanism:molecular motion,turbulent diffusion,and circumferential non-uniformities,the last of which includes secondary flow effects and others,Therefore the equation system unifles the two models for spanwise mixing coefficients defined and introduced into the basic equation system,a novel,much simpler equation system,without additional unknown correlation terms included,has been obtained.This novel equation system makes throughflow computations including mixing far easier for multistage compressors .It has been rigorously shown that these apparent mixing coefficients contain full information of all the three kinds of mixing mechanism,so that the simpler equation system can also be taken as a unified model for meridional flows with all the dinds of the mixing effects.Calculations of the flow through multistage machines have been made by incorporating the new model into a streamline curvature throughflow calculation method and the improved agreement with experimental data has been obtained.It is believed that the simpler equation system can be apphed to the flows not only in subsonic but in transonic and supersonic compressors if an appropriate model is propsed for the apparent mixing coeffcients.

  6. Aerodynamic Analysis of Multistage Turbomachinery Flows in Support of Aerodynamic Design

    Science.gov (United States)

    Adamczyk, John J.

    1999-01-01

    This paper summarizes the state of 3D CFD based models of the time average flow field within axial flow multistage turbomachines. Emphasis is placed on models which are compatible with the industrial design environment and those models which offer the potential of providing credible results at both design and off-design operating conditions. The need to develop models which are free of aerodynamic input from semi-empirical design systems is stressed. The accuracy of such models is shown to be dependent upon their ability to account for the unsteady flow environment in multistage turbomachinery. The relevant flow physics associated with some of the unsteady flow processes present in axial flow multistage machinery are presented along with procedures which can be used to account for them in 3D CFD simulations. Sample results are presented for both axial flow compressors and axial flow turbines which help to illustrate the enhanced predictive capabilities afforded by including these procedures in 3D CFD simulations. Finally, suggestions are given for future work on the development of time average flow models.

  7. Three-Dimensional, Unsteady, Parallel Simulation of a Multi-Stage Turbine with Conjugate Heat Transfer

    Science.gov (United States)

    Lee, Daryl Yao-Wah

    A computational fluid dynamics (CFD) procedure has been developed to predict the three-dimensional unsteady flow through a multi-stage axial turbine including the effects of heat transfer. This procedure simultaneously solves the unsteady Reynold's-averaged Navier-Stokes equations for the flow along with the heat conduction equation for the solid. Solution time is minimized through the use of multiple central processing units (CPUs). The blades of the multi-stage turbine move in time and the flow interacts with adjacent vane (stationary) passages through the use of a parallel, sliding-grid, inter-blade-row treatment. Described are the techniques used to solve the governing equations, the inter-blade-row treatment, and the parallelization of the overall approach. The uniqueness of this prediction method lies in the unsteady, multi-stage conjugate solution and the use of multiple combined cores. The approach is validated for the High Impact Technology Turbine designed and tested at the Air Force Research Laboratory.

  8. Immunogenic multistage recombinant protein vaccine confers partial protection against experimental toxoplasmosis mimicking natural infection in murine model

    Directory of Open Access Journals (Sweden)

    Yaprak Gedik

    2016-01-01

    To generate a protective vaccine against toxoplasmosis, multistage vaccines and usage of challenging models mimicking natural route of infection are critical cornerstones. In this study, we generated a BAG1 and GRA1 multistage vaccine that induced strong immune response in which the protection was not at anticipated level. In addition, the murine model was orally challenged with tissue cysts to mimic natural route of infection.

  9. Indiana forest cover mapping based on multi-stage integrated classification using satellite and in situ forest inventory data

    Science.gov (United States)

    Shao, Gang

    Forest species classification through remote sensing data is a complex process, which usually is done either at a coarse level or with low accuracy. This study examines a multi-stage classification algorithm combining supervised and unsupervised classifications to classify forest areas in Indiana. Integrated classification makes the procedures automatic and reduces human errors. Splitting the classification into two steps increases the accuracy with limited ground data. In the first step, in which the Indiana state forest area is classified, the point plug-in classification algorithm is employed, because plenty of ground data are available. In the second step the classifying of the state forest including a surrounding 8km buffer, the ground data are insufficient to process the point plug-in classification approach. In this case, the polygon plug-in classification algorithm is used to realize the extended area classification at the second stage. The resultant land cover map has six tree species (conifer, mixed forest, oak and hickory, mixed oak and hickory/ hardwood, maple and other hardwood). The overall accuracy is 81.93%.

  10. Reconstruction of multistage massive rock slope failure: Polymethodical approach in Lake Oeschinen (CH)

    Science.gov (United States)

    Knapp, Sibylle; Gilli, Adrian; Anselmetti, Flavio S.; Hajdas, Irka

    2016-04-01

    Lateglacial and Holocene rock-slope failures occur often as multistage failures where paraglacial adjustment and stress adaptation are hypothesised to control stages of detachment. However, we have only limited datasets to reconstruct detailed stages of large multistage rock-slope failures, and still aim at improving our models in terms of geohazard assessment. Here we use lake sediments, well-established for paleoclimate and paleoseismological reconstruction, with a focus on the reconstruction of rock-slope failures. We present a unique inventory from Lake Oeschinen (Bernese Alps, Switzerland) covering about 2.4 kyrs of rock-slope failure history. The lake sediments have been analysed using sediment-core analysis, radiocarbon dating and seismic-to-core and core-to-core correlations, and these were linked to historical and meteorological records. The results imply that the lake is significantly younger than the ~9 kyrs old Kandersteg rock avalanche (Tinner et al., 2005) and shows multiple rock-slope failures, two of which could be C14-dated. Several events detached from the same area potentially initiated by prehistoric earthquakes (Monecke et al., 2006) and later from stress relaxation processes. The data imply unexpected short recurrence rates that can be related to certain detachment scarps and also help to understand the generation of a historical lake-outburst flood. Here we show how polymethodical analysis of lake sediments can help to decipher massive multistage rock-slope failure. References Monecke, K., Anselmetti, F.S., Becker, A., Schnellmann, M., Sturm, M., Giardini, D., 2006. Earthquake-induced deformation structures in lake deposits: A Late Pleistocene to Holocene paleoseismic record for Central Switzerland. Eclogae Geologicae Helvetiae, 99(3), 343-362. Tinner, W., Kaltenrieder, P., Soom, M., Zwahlen, P., Schmidhalter, M., Boschetti, A., Schlüchter, C., 2005. Der nacheiszeitliche Bergsturz im Kandertal (Schweiz): Alter und Auswirkungen auf die

  11. A timer inventory based upon manual and automated analysis of ERTS-1 and supporting aircraft data using multistage probability sampling. [Plumas National Forest, California

    Science.gov (United States)

    Nichols, J. D.; Gialdini, M.; Jaakkola, S.

    1974-01-01

    A quasi-operational study demonstrating that a timber inventory based on manual and automated analysis of ERTS-1, supporting aircraft data and ground data was made using multistage sampling techniques. The inventory proved to be a timely, cost effective alternative to conventional timber inventory techniques. The timber volume on the Quincy Ranger District of the Plumas National Forest was estimated to be 2.44 billion board feet with a sampling error of 8.2 percent. Costs per acre for the inventory procedure at 1.1 cent/acre compared favorably with the costs of a conventional inventory at 25 cents/acre. A point-by-point comparison of CALSCAN-classified ERTS data with human-interpreted low altitude photo plots indicated no significant differences in the overall classification accuracies.

  12. Multistage still

    Energy Technology Data Exchange (ETDEWEB)

    Franco, J.; Saravia, L.R.; Esteban, S.

    1999-07-01

    A new design for a passive atmospheric multiple effect solar distillation unit is proposed. Inclined glass surfaces with a 4{degree} slope and placed one over the other in an isolated box are used. The cold salty water is fed only in the upper stage and flows along each surface, falling from one stage to the next by gravity and reaching finally a heated tray at the bottom. Vapor condenses below each surface and produces the water evaporation in the upper side of the same surface. For heating the bottom of the still a simple 1.3 m{sup 2} solar collector with a fresnel type concentrator is used. The collector is separated from the still and heat is transported from one unit to the other using a 4 kg aluminium slab, which is placed in the absorber and it is heated at a temperature about 350 C. The slab is then placed below the tray in an isolated box. Four slabs are used and they are changed periodically when the slab temperature drops below approximately 180 C. Several slabs can be used for heat storage if several collectors are built, allowing the use of the still during some hours at night, improving its daily productivity. Experiments have been performed with a prototype and the results are discussed and compared with the values obtained with another electrically heated prototype.

  13. Numerical simulation of three-dimensional turbulent flow in multistage axial compressor blade row

    Institute of Scientific and Technical Information of China (English)

    Jian JIANG; Bo LIU; Yangang WANG; Xiangyi NAN

    2008-01-01

    Numerical simulation of three-dimensional turbulent flow in a multistage axial compressor blade row is conducted. A high resolution, third-order ENN scheme is adopted to catch the shockwave and simulate the turbulent flow correctly, while an LU-SGS implicit method is chosen to improve computation rate. A detailed and highly efficient numerical simulation system is thus constructed. The investigation is focused on the grid con-necting methods between the rotor and the stator and the corresponding treatment of rotor-stator interactional sur-face. The final results of a three-stage axial compressor with inlet guide vanes conform well to the experimental data.

  14. Research on EMI Reduction of Multi-stage Interleaved Bridgeless Power Factor Corrector

    DEFF Research Database (Denmark)

    Li, Qingnan; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2012-01-01

    Working as an electronic pollution eliminator, the Power Factor Corrector's (PFC) own Electromagnetic Interference (EMI) problems have been blocking its performance improvement for long. In this paper, a systematic research on EMI generation of a multi-stage Two-Boost-Circuit Interleaved Bridgeless...... PFC (IBPFC) is presented. The insight into relationship of interleaving stages, switching on/off oscillations and EMI reduction is discussed. Finally, a 3.5kW universal input 2-stage IBPFC prototype was built to verify the theoretical analysis. Experimental results show that significant EMI reductions...

  15. Strategies and limits in multi-stage single-point incremental forming

    DEFF Research Database (Denmark)

    Skjødt, Martin; Silva, M.B.; Martins, P. A. F.

    2010-01-01

    with vertical walls. The strategy consists of forming a conical cup with a taper angle in the first stage, followed by three subsequent stages that progressively move the conical shape towards the desired cylindrical geometry. The investigation includes material characterization, determination of forming...... paths. The results also reveal that the sequence of multi-stage forming has a large effect on the location of strain points in the principal strain space. Strain paths are linear in the first stage and highly non-linear in the subsequent forming stages. The overall results show that the experimentally...

  16. Analisis Performansi Pompa Multistage Pengisi Air Umpan Ketel Yang Digerakkan Oleh Turbin Uap Dibanding Dengan Elektromotor

    OpenAIRE

    Nasution, Asril Habibi

    2012-01-01

    The pump is a fluid machinery that serves to move the fluid from the fluid incompressible / low pressure to the place / higher pressure. In principle, the pump convert mechanical energy into fluid energy. Centrifugal pump is included into the type of dynamic pressure pumps, which pump impeller type has a function to remove fluid from a low place to place a higher or lower than the pressure to higher pressure. In this analysis the pump used is a multistage centrifugal pump is driven by the ste...

  17. Vibration Analysis of a Multi-Stage Gear System Including Drive Mechanism Elements

    Science.gov (United States)

    Tanaka, Eiichirou; Tanaka, Naoyuki; Ohno, Kousaku

    We have developed a new method for building a vibration model of an actual gear-drive system. Each gear has six degrees of freedom: three translational and three rotational motions. Stiffness matrixes representing each gear shaft and tooth meshing were made and overlapped into one stiffness matrix for the whole system. This enabled easy modelling of complex gear-drive systems such as multi-stage gears and branched gears. The results are in good agreement with experimental results with respect to the major resonance frequencies and vibration modes.

  18. A Simple Method of FLow Field DIagnosis in Multistage Axial Flow Compressors

    Institute of Scientific and Technical Information of China (English)

    JieLiu; DajunYe

    1994-01-01

    The calculating method of flow field diagnosis in multistage axial compressors is presented in this paper.The distributions of loss and deviation angle of every blade row,and blockage factors are evalusted using tested total temperature and total pressure at inlet and outlet of compressor,as well as the endwall static pressures.One operating Mode of a two-stage fan is presented comparing results from the diagnostic method with measurements,and the results have demonstrated the important effects of diagnostic method.

  19. Multistage Off-Line Permutation Packet Routing on a Mesh: An Approach with Elementary Mathematics

    Institute of Scientific and Technical Information of China (English)

    Kevin Chiew; Yingjiu Li

    2009-01-01

    Various methods have been proposed for off-line permutation packet routing on a mesh. One of the methods is known as multistage routing, in which the first stage is crucial. For the first stage of routing, the previous study normally converts it to a problem of graph theory and proves the existence of solutions. However, there is a lack of simple algorithms to the first stage of routing. This article presents an explicit and simple approach for the first stage of routing based on elementary mathematics.

  20. Optimization on Production-Inventory Problem with Multistage and Varying Demand

    Directory of Open Access Journals (Sweden)

    Duan Gang

    2012-01-01

    Full Text Available This paper addresses production-inventory problem for the manufacturer by explicitly taking into account multistage and varying demand. A nonlinear hybrid integer constrained optimization is modeled to minimize the total cost including setup cost and holding cost in the planning horizon. A genetic algorithm is developed for the problem. A series of computational experiments with different sizes is used to demonstrate the efficiency and universality of the genetic algorithm in terms of the running time and solution quality. At last the combination of crossover probability and mutation probability is tested for all problems and a law is found for large size.

  1. Oscillating Disturbance Propagation in Passages of Multi-Stage Hydrogen Turbine

    Institute of Scientific and Technical Information of China (English)

    刘红; 郑晓琳; 陈佐一

    2001-01-01

    The propagation of oscillating disturbances with various frequencies in multi-stage turbine passages in a rocket is analyzed using the oscillating fluid mechanics theorem and the parametric polynomial method. The results show that oscillating disturbances can be rapidly dissipated when the disturbance occurs at the inlet except for very high-frequency oscillation such as 50 kHz. Dangerous low-frequency oscillations occur at the outlet. The effects of the flow parameter variations on the oscillating disturbance propagation are also studied. The analysis will facilitate safe operation of the whole rocket system.

  2. Estimation of the Residual Fatigue Life of Laminated Composites Under a Multistage Cyclic Loading

    Science.gov (United States)

    Strizhius, V.

    2016-11-01

    Problems on estimation of the residual fatigue life of laminated composites under a multistage regular cyclic loading (with a constant amplitude at each loading stage) are among the most frequently ones encountered in the practice of fatigue life estimations of laminated composites. There are several methods for solving these problems, but their use not always gives results of acceptable accuracy. To improve the accuracy of such estimations for the type of cyclic loading mentioned, a special model of nonlinear accumulation of fatigue damage is proposed.

  3. Enhanced Multistage Homotopy Perturbation Method: Approximate Solutions of Nonlinear Dynamic Systems

    Directory of Open Access Journals (Sweden)

    Daniel Olvera

    2014-01-01

    Full Text Available We introduce a new approach called the enhanced multistage homotopy perturbation method (EMHPM that is based on the homotopy perturbation method (HPM and the usage of time subintervals to find the approximate solution of differential equations with strong nonlinearities. We also study the convergence of our proposed EMHPM approach based on the value of the control parameter h by following the homotopy analysis method (HAM. At the end of the paper, we compare the derived EMHPM approximate solutions of some nonlinear physical systems with their corresponding numerical integration solutions obtained by using the classical fourth order Runge-Kutta method via the amplitude-time response curves.

  4. Multi-Stage Optimization Based Automatic Voltage Control Systems Considering Wind Power Forecasting Errors

    DEFF Research Database (Denmark)

    Qin, Nan; Bak, Claus Leth; Abildgaard, Hans

    2017-01-01

    cost and the generator reactive power output cost. The problem is formulated in a multi-stage optimal reactive power flow (MORPF) framework, solved by the nonlinear programming techniques via a rolling process. The voltage uncertainty caused by wind power forecasting errors is considered in the optimal......This paper proposes an automatic voltage control (AVC) system for power systems with limited continuous voltage control capability. The objective is to minimize the operational cost over a period, which consists of the power loss in the grid, the shunt switching cost, the transformer tap change...

  5. Mathematical modeling on multi-stage series crushing ratio distribution based on fuzzy physical programming

    Institute of Scientific and Technical Information of China (English)

    Yu-Long QI; Chen-Chen CAI; Ping-Zhen LANG

    2013-01-01

    Double-layer,multi-roller plate crusher is a new device,that uses a multi-stage series crushing style to break particles,with the crushing ratio distribution directly influencing the machine's performance.Three crushing ratios of 2.25,2.15 and 2.0 1,used for fuzzy physical programming,were determined.The comparison of the optimized result between the double-layer multi-roller plate crusher and a high pressure roll grinder showed that the double-layer multi-roller plate crusher had a better performance,reducing crushing force and wear.

  6. Study of flow instability in off design operation of a multistage centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Akiha; Maeda, Manabu; Kamei, Shun; Hazama, Ryota; Sano, Takeshi; Iino, Masamichi [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Hiramatsu, Hideto; Komaki, Shutaro; Miyagawa, Kazuyoshi [Waseda University, Okubo (Japan)

    2016-02-15

    In recent years, attempts have been made to make multistage centrifugal pumps smaller in size and more efficient. However, such designs are known to cause positive-slope phenomena in the Q-H curve, especially under low-flow conditions. These phenomena, which have thus far been studied experimentally and numerically, stem from flow instability in the pump. However, their mechanisms have not yet been clarified because it depends on various parameters. In this study, we focused on diffuser rotating stall, observed in positive Q-H characteristics. This study elucidates the mechanism of positive-slope generation through experimental results and two-dimensional numerical analysis.

  7. A Predictive Model of Multi-Stage Production Planning for Fixed Time Orders

    Directory of Open Access Journals (Sweden)

    Kozłowski Edward

    2014-09-01

    Full Text Available The traditional production planning model based upon a deterministic approach is well described in the literature. Due to the uncertain nature of manufacturing processes, such model can however incorrectly represent actual situations on the shop floor. This study develops a mathematical modeling framework for generating production plans in a multistage manufacturing process. The devised model takes into account the stochastic model for predicting the occurrence of faulty products. The aim of the control model is to determine the number of products which should be manufactured in each planning period to minimize both manufacturing costs and potential financial penalties for failing to fulfill the order completely.

  8. European dominance in multistage ultramarathons: an analysis of finisher rate and performance trends from 1992 to 2010.

    Science.gov (United States)

    Shoak, Mohannad Abou; Knechtle, Beat; Rüst, Christoph Alexander; Lepers, Romuald; Rosemann, Thomas

    2013-01-01

    Participation and performance trends regarding the nationality of ultraendurance athletes have been investigated in the triathlon, but not in running. The present study aimed to identify the countries in which multistage ultramarathons were held around the world and the nationalities of successful finishers. Finisher rates and performance trends of finishers in multistage ultramarathons held worldwide between 1992 and 2010 were investigated. Between 1992 and 2010, the bulk of multistage ultramarathons were held in Germany and France, with more than 30 races organized in each country. Completion rates for men and women increased exponentially, with women representing on average 16.4% of the total field. Since 1992, 6480 athletes have competed in Morocco, 2538 in Germany, and 1842 in France. A total of 81.9% of athletes originated from Europe, and more specifically from France (22.9%), Great Britain (18.0%), and Germany (13.4%). European ultramarathoners dominated the athletes who completed multistage ultramarathons worldwide, with specific dominance of French, British, and German athletes. Future studies should investigate social aspects, such as sport tourism, among European athletes to understand why European athletes are so interested in participating in multistage ultramarathons.

  9. Therapeutic potential of human induced pluripotent stem cells in experimental stroke.

    Science.gov (United States)

    Chang, Da-Jeong; Lee, Nayeon; Park, In-Hyun; Choi, Chunggab; Jeon, Iksoo; Kwon, Jihye; Oh, Seung-Hun; Shin, Dong Ah; Do, Jeong Tae; Lee, Dong Ryul; Lee, Hyunseung; Moon, Hyeyoung; Hong, Kwan Soo; Daley, George Q; Song, Jihwan

    2013-01-01

    Ischemic stroke mainly caused by middle cerebral artery occlusion (MCAo) is a major type of stroke, but there are currently very limited therapeutic options for its cure. Neural stem cells (NSCs) or neural precursor cells (NPCs) derived from various sources are known to survive and improve neurological functions when they are engrafted in animal models of stroke. Induced pluripotent stem cells (iPSCs) generated from somatic cells of patients are novel cells that promise the autologous cell therapy for stroke. In this study, we successfully differentiated iPSCs derived from human fibroblasts into NPCs and found their robust therapeutic potential in a rodent MCAo stroke model. We observed the significant graft-induced behavioral recovery, as well as extensive neural tissue formation. Animal MRI results indicated that the majority of contralaterally transplanted iPSC-derived NPCs migrated to the peri-infarct area, showing a pathotropism critical for tissue recovery. The transplanted animals exhibited the significant reduction of stroke-induced inflammatory response, gliosis and apoptosis, and the contribution to the endogenous neurogenesis. Our results demonstrate that iPSC-derived NPCs are effective cells for the treatment of stroke.

  10. Use of human stem cells in Huntington disease modeling and translational research.

    Science.gov (United States)

    Golas, Monika M; Sander, Bjoern

    2016-04-01

    Huntington disease (HD) is a devastating neurological disorder caused by an extended CAG repeat in exon 1 of the gene that encodes the huntingtin (HTT) protein. HD pathology involves a loss of striatal medium spiny neurons (MSNs) and progressive neurodegeneration affects the striatum and other brain regions. Because HTT is involved in multiple cellular processes, the molecular mechanisms of HD pathogenesis should be investigated on multiple levels. On the cellular level, in vitro stem cell models, such as induced pluripotent stem cells (iPSCs) derived from HD patients and HD embryonic stem cells (ESCs), have yielded progress. Approaches to differentiate functional MSNs from ESCs, iPSCs, and neural stem/progenitor cells (NSCs/NPCs) have been established, enabling MSN differentiation to be studied and disease phenotypes to be recapitulated. Isolation of target stem cells and precursor cells may also provide a resource for grafting. In animal models, transplantation of striatal precursors differentiated in vitro to the striatum has been reported to improve disease phenotype. Initial clinical trials examining intrastriatal transplantation of fetal neural tissue suggest a more favorable clinical course in a subset of HD patients, though shortcomings persist. Here, we review recent advances in the development of cellular HD models and approaches aimed at cell regeneration with human stem cells. We also describe how genome editing tools could be used to correct the HTT mutation in patient-specific stem cells. Finally, we discuss the potential and the remaining challenges of stem cell-based approaches in HD research and therapy development.

  11. Multi-stage ponds-wetlands ecosystem for effective wastewater treatment

    Institute of Scientific and Technical Information of China (English)

    PENG Jian-feng; WANG Bao-zhen; WANG Lin

    2005-01-01

    The performance of the Dongying multi-stage ponds-wetlands ecosystem was investigated in this work. Study of the removal of different pollutants (BOD5, COD, SS, TP, TN, NH3-N, etc.) in different temperature seasons and different units in this system indicated that effluent BOD5 and SS were constant to less than 11 mg/L and 14 mg/L throughout the experimental processes; but that the removal efficiencies of pollutants such as TP, TN, NH3-N, COD varied greatly with season. The higher the temperature was, the higher was the observed removal in this system. Additionally, each unit of the system functioned differently in removing pollutants. BOD5 and SS were mainly removed in the first three units (hybrid facultative ponds, aeration ponds and aerated fish ponds), whereas nitrogen and phosphates were mainly removed in hydrophyte ponds and constructed reed wetlands.The multi-stage ponds-wetlands ecosystem exhibits good potential of removing different pollutants, and the effluent quality meet several standards for wastewater reuse.

  12. A novel multi-stage direct contact membrane distillation module: Design, experimental and theoretical approaches.

    Science.gov (United States)

    Lee, Jung-Gil; Kim, Woo-Seung; Choi, June-Seok; Ghaffour, Noreddine; Kim, Young-Deuk

    2016-12-15

    An economic desalination system with a small scale and footprint for remote areas, which have a limited and inadequate water supply, insufficient water treatment and low infrastructure, is strongly demanded in the desalination markets. Here, a direct contact membrane distillation (DCMD) process has the simplest configuration and potentially the highest permeate flux among all of the possible MD processes. This process can also be easily instituted in a multi-stage manner for enhanced compactness, productivity, versatility and cost-effectiveness. In this study, an innovative, multi-stage, DCMD module under countercurrent-flow configuration is first designed and then investigate both theoretically and experimentally to identify its feasibility and operability for desalination application. Model predictions and measured data for mean permeate flux are compared and shown to be in good agreement. The effect of the number of module stages on the mean permeate flux, performance ratio and daily water production of the MDCMD system has been theoretically identified at inlet feed and permeate flow rates of 1.5 l/min and inlet feed and permeate temperatures of 70 °C and 25 °C, respectively. The daily water production of a three-stage DCMD module with a membrane area of 0.01 m(2) at each stage is found to be 21.5 kg. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Analysis of the multistage cyclic loading test on resilient modulus value64

    Directory of Open Access Journals (Sweden)

    Sas Wojciech

    2016-03-01

    Full Text Available Analysis of the multistage cyclic loading test on resilient modulus value. Upon cyclic excitation of soil mass, two types of strain can be recognized, namely elastic and plastic one. Proper analysis of these two types of deformations can help engineers in designing more reliable structures. In this study, a multistage uniaxial cyclic loading in unconfined conditions was performed. Tests were performed in order to characterize strain response to repeated excitation. Soil sample under cyclic loading was recognized as exhibiting the symptoms of a plastic strain growth during the cyclic loading process with exponential manner, when compared to number of cycles. Soil in this study was reconstituted and compacted by using the Proctor method to simulate conditions similar to those affecting the road subbase. The soil was recognized as sandy clay. Results were analysed and a proposition of empirical formula for plastic strain calculation with the use of characteristic stress values was presented. The resilient modulus values were also calculated. The Mr value was within range from 45 to 105 MPa. The conclusions concerning the cyclically loaded soil in uniaxial conditions were presented.

  14. How quantitative measures unravel design principles in multi-stage phosphorylation cascades.

    Science.gov (United States)

    Frey, Simone; Millat, Thomas; Hohmann, Stefan; Wolkenhauer, Olaf

    2008-09-07

    We investigate design principles of linear multi-stage phosphorylation cascades by using quantitative measures for signaling time, signal duration and signal amplitude. We compare alternative pathway structures by varying the number of phosphorylations and the length of the cascade. We show that a model for a weakly activated pathway does not reflect the biological context well, unless it is restricted to certain parameter combinations. Focusing therefore on a more general model, we compare alternative structures with respect to a multivariate optimization criterion. We test the hypothesis that the structure of a linear multi-stage phosphorylation cascade is the result of an optimization process aiming for a fast response, defined by the minimum of the product of signaling time and signal duration. It is then shown that certain pathway structures minimize this criterion. Several popular models of MAPK cascades form the basis of our study. These models represent different levels of approximation, which we compare and discuss with respect to the quantitative measures.

  15. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

    Science.gov (United States)

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J.; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-01-01

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes. PMID:27545955

  16. A Dynamic Multistage Hybrid Swarm Intelligence Optimization Algorithm for Function Optimization

    Directory of Open Access Journals (Sweden)

    Daqing Wu

    2012-01-01

    Full Text Available A novel dynamic multistage hybrid swarm intelligence optimization algorithm is introduced, which is abbreviated as DM-PSO-ABC. The DM-PSO-ABC combined the exploration capabilities of the dynamic multiswarm particle swarm optimizer (PSO and the stochastic exploitation of the cooperative artificial bee colony algorithm (CABC for solving the function optimization. In the proposed hybrid algorithm, the whole process is divided into three stages. In the first stage, a dynamic multiswarm PSO is constructed to maintain the population diversity. In the second stage, the parallel, positive feedback of CABC was implemented in each small swarm. In the third stage, we make use of the particle swarm optimization global model, which has a faster convergence speed to enhance the global convergence in solving the whole problem. To verify the effectiveness and efficiency of the proposed hybrid algorithm, various scale benchmark problems are tested to demonstrate the potential of the proposed multistage hybrid swarm intelligence optimization algorithm. The results show that DM-PSO-ABC is better in the search precision, and convergence property and has strong ability to escape from the local suboptima when compared with several other peer algorithms.

  17. Population balance modelling and multi-stage optimal control of a pulsed spray fluidized bed granulation.

    Science.gov (United States)

    Liu, Huolong; Li, Mingzhong

    2014-07-01

    In this work, one-dimensional population balance models (PBMs) have been developed to model a pulsed top-spray fluidized bed granulation. The developed PBMs have linked the key binder solution spray operating factors of the binder spray rate, atomizing air pressure and pulsed frequency of spray with the granule properties to predict granule growth behaviour in the pulsed spray fluidized bed granulation process at different operating conditions with accuracy. A multi-stage open optimal control strategy based on the developed PBMs was proposed to reduce the model mismatch, in which through adjusting the trajectory of the evolution of the granule size distribution at predefined sample intervals, to determine the optimal operating variables related to the binder spray including the spray rate of binding liquid, atomizing air pressure and pulsed frequency of spray. The effectiveness of the proposed modelling and multi-stage open optimal control strategies has been validated by experimental and simulation tests. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Modelling and Control of the Multi-stage Cable Pulley-driven Flexible-joint Robot

    Directory of Open Access Journals (Sweden)

    Phongsaen Pitakwatchara

    2014-07-01

    Full Text Available This work is concerned with the task space impedance control of a robot driven through a multi-stage nonlinear flexible transmission system. Specifically, a two degrees-of-freedom cable pulley-driven flexible-joint robot is considered. Realistic modelling of the system is developed within the bond graph modelling framework. The model captures the nonlinear compliance behaviour of the multi-stage cable pulley transmission system, the spring effect of the augmented counterbalancing mechanism, the major loss throughout the system elements, and the typical inertial dynamics of the robot. Next, a task space impedance controller based on limited information about the angle and the current of the motors is designed. The motor current is used to infer the transmitted torque, by which the motor inertia may be modulated. The motor angle is employed to estimate the stationary distal robot link angle and the robot joint velocity. They are used in the controller to generate the desired damping force and to shape the potential energy of the flexible joint robot system to the desired configuration. Simulation and experimental results of the controlled system signify the competency of the proposed control law.

  19. Learning representations for object classification using multi-stage optimal component analysis.

    Science.gov (United States)

    Wu, Yiming; Liu, Xiuwen; Mio, Washington

    2008-01-01

    Learning data representations is a fundamental challenge in modeling neural processes and plays an important role in applications such as object recognition. Optimal component analysis (OCA) formulates the problem in the framework of optimization on a Grassmann manifold and a stochastic gradient method is used to estimate the optimal basis. OCA has been successfully applied to image classification problems arising in a variety of contexts. However, as the search space is typically very high dimensional, OCA optimization often requires expensive computational cost. In multi-stage OCA, we first hierarchically project the data onto several low-dimensional subspaces using standard techniques, then OCA learning is performed hierarchically from the lowest to the highest levels to learn about a subspace that is optimal for data discrimination based on the K-nearest neighbor classifier. One of the main advantages of multi-stage OCA lies in the fact that it greatly improves the computational efficiency of the OCA learning algorithm without sacrificing the recognition performance, thus enhancing its applicability to practical problems. In addition to the nearest neighbor classifier, we illustrate the effectiveness of the learned representations on object classification used in conjunction with classifiers such as neural networks and support vector machines.

  20. Multistage A-O Activated Sludge Process for Paraformaldehyde Wastewater Treatment and Microbial Community Structure Analysis

    Directory of Open Access Journals (Sweden)

    Danyang Zheng

    2016-01-01

    Full Text Available In recent years, the effect of formaldehyde on microorganisms and body had become a global public health issue. The multistage combination of anaerobic and aerobic process was adopted to treat paraformaldehyde wastewater. Microbial community structure in different reaction stages was analyzed through high-throughput sequencing. Results showed that multistage A-O activated sludge process positively influenced polyformaldehyde wastewater. The removal rates of formaldehyde were basically stable at more than 99% and those of COD were about 89%. Analysis of the microbial diversity index indicated that the microbial diversity of the reactor was high, and the treatment effect was good. Moreover, microbial community had certain similarity in the same system. Microbial communities in different units also showed typical representative characteristics affected by working conditions and influent concentrations. Proteobacteria, Firmicutes, and Bacteroidetes were the dominant fungal genera in the phylum level of community composition. As to family and genus levels, Peptostreptococcaceae was distributed at various stages and the dominant in this system. This bacterium also played an important role in organic matter removal, particularly decomposition of the acidified middle metabolites. In addition, Rhodobacteraceae and Rhodocyclaceae were the formaldehyde-degrading bacteria found in the reactor.

  1. A novel multi-stage direct contact membrane distillation module: Design, experimental and theoretical approaches

    KAUST Repository

    Lee, Jung Gil

    2016-10-24

    An economic desalination system with a small scale and footprint for remote areas, which have a limited and inadequate water supply, insufficient water treatment and low infrastructure, is strongly demanded in the desalination markets. Here, a direct contact membrane distillation (DCMD) process has the simplest configuration and potentially the highest permeate flux among all of the possible MD processes. This process can also be easily instituted in a multi-stage manner for enhanced compactness, productivity, versatility and cost-effectiveness. In this study, an innovative, multi-stage, DCMD module under countercurrent-flow configuration is first designed and then investigate both theoretically and experimentally to identify its feasibility and operability for desalination application. Model predictions and measured data for mean permeate flux are compared and shown to be in good agreement. The effect of the number of module stages on the mean permeate flux, performance ratio and daily water production of the MDCMD system has been theoretically identified at inlet feed and permeate flow rates of 1.5 l/min and inlet feed and permeate temperatures of 70 °C and 25 °C, respectively. The daily water production of a three-stage DCMD module with a membrane area of 0.01 m2 at each stage is found to be 21.5 kg.

  2. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

    Science.gov (United States)

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J.; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-08-01

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes.

  3. Adjoint Optimization of Multistage Axial Compressor Blades with Static Pressure Constraint at Blade Row Interface

    Science.gov (United States)

    Yu, Jia; Ji, Lucheng; Li, Weiwei; Yi, Weilin

    2016-06-01

    Adjoint method is an important tool for design refinement of multistage compressors. However, the radial static pressure distribution deviates during the optimization procedure and deteriorates the overall performance, producing final designs that are not well suited for realistic engineering applications. In previous development work on multistage turbomachinery blade optimization using adjoint method and thin shear-layer N-S equations, the entropy production is selected as the objective function with given mass flow rate and total pressure ratio as imposed constraints. The radial static pressure distribution at the interfaces between rows is introduced as a new constraint in the present paper. The approach is applied to the redesign of a five-stage axial compressor, and the results obtained with and without the constraint on the radial static pressure distribution at the interfaces between rows are discussed in detail. The results show that the redesign without the radial static pressure distribution constraint (RSPDC) gives an optimal solution that shows deviations on radial static pressure distribution, especially at rotor exit tip region. On the other hand, the redesign with the RSPDC successfully keeps the radial static pressure distribution at the interfaces between rows and make sure that the optimization results are applicable in a practical engineering design.

  4. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination.

    Science.gov (United States)

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-08-22

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes.

  5. Analytical fractionation of aquatic humic substances and their metal species by means of multistage ultrafiltration.

    Science.gov (United States)

    Aster, B; Burba, P; Broekaert, J A

    1996-03-01

    The molecular-size fractionation of aquatic humic substances (HS) and their metal species by means of a novel sequential-stage ultrafiltration (UF) device equipped with five appropriate ultramembranes (1, 5, 10, 50 and 100 kD) is described. First of all, the concentration dynamics of macromolecules, particulary HS, during five-stage UF and its subsequent washing step has been modelled. Based on these results, the fractionation of aquatic HS (from ground and bog water) by means of multistage UF has been optimized for an analytical scale (10 ml sample, 1 mg/ml HS, 10 ml washing solution, pH 6.0). The molecular size-distribution of selected aquatic HS (BOC 1/2 from the "DFG-Versuchsfeld Bocholt", VM 5 from "Venner Moor", Germany) studied by five-stage UF exhibited strong systematic influences of the procedure used for their isolation. The molecular-size distribution of HS obtained by on-line UF and gel permeation chromatography (GPC) showed a satisfactory agreement in the range 1-50 kD. Moreover, when interrupting multistage UF for > 48 h a slow transformation in the HS samples has been found as gradually additional HS fractions of complexation time. Metal determinations as carried out by flame AAS, showed that considerable metal fractions in HS especially are present in molecules > 50 kD, which seemed to be rather acid-inert. With complexation times of 10 kD) has been found.

  6. Multistage Development of Müller-Achenbach model for Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Simin A. Oshkovr

    2008-01-01

    Full Text Available This research focused on the conceptual development of constitutive Müller-Achenbach model and proceeds to construct a model based on phase transition under changing temperature and load for variants of martensite in shape memory alloy CuAlNi (Copper-aluminum-nickel. Problem statement: Motivation of this research is rare information of a variant of martensite phase (M++ and prediction of the shape recovery of shape memory alloy in this stage of transformation. Approach: The mathematical equations proposed a prediction of stability of Austenite phases and extend it to multistage martensitic phase transformation. These phase transformations occurred by loading on the material. Equations described free energy landscape in CuAlNi shape memory alloys at low (260K and high temperature (440K. The model evaluated the free energy due to the phase transformation between the austenite and multistage martensitic structures. Results: Results for M++ phase showed decrease in temperature from 440K to 260K presented decrease in stress approximately from 1 kN to 0.4kN and free energy from 5 kJ/kg to 0.1 kJ/kg. Equations have been solved and plotted by software programmed in MATLAB. Conclusions/Recommendations: The model which has derived focused on homogeneous shape memory alloys, but future performance requirements will most likely be met with heterogeneous materials. Therefore, simulation models for heterogeneous materials must be developed.

  7. Optimal Design of Multistage Two-Dimensional Cellular-Cored Sandwich Panel Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Yongcun Zhang

    2014-08-01

    Full Text Available For a two-dimensional (2D cellular-cored sandwich panel heat exchanger, there exists an optimum cell size to achieve the maximum heat transfer with the prescribed pressure drop when the length is fixed and the two plates are isothermal. However, in engineering design, it is difficult to find 2D cellular materials with the ideal cell size because the cell size selected must be from those commercially available, which are discrete, not continuous. In order to obtain the maximum heat dissipation, an innovative design scheme is proposed for the sandwich panel heat exchanger which is divided into multiple stages in the direction of fluid flow where the 2D cellular material in each stage has a specific cell size. An analytical model is presented to evaluate the thermal performance of the multistage sandwich panel heat exchanger when all 2D cellular materials have the same porosity. Also, a new parameter named equivalent cell size (ECS is defined, which is dependent on the cell size and length of cellular material in all stages. Results show that the maximum heat dissipation design of the multistage sandwich panel heat exchanger can be converted to make the ECS equal to the optimal cell size of the single-stage exchanger.

  8. The advantage of variable speed for multistage centrifugal blowers used in waste-water treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Huang, X. [Gardner Denver Incorp., Peachtree City, GA (United States)

    1999-07-01

    The multistage centrifugal blower is primarily a 60 Hz market product. A two-pole AC induction motor directly drives the blower at 3600 RPM. These blowers have been used widely for the last three decades in the US for waste water treatment plant applications (WWTP) due to their simple design and rugged construction. The cost of energy drives the market towards not only an efficient single design point but also an efficient operating range when both flow and pressure are varied. On the other hand, if a blower is running at 3000 RPM as in the 50 Hz market, about 20% of flow and 40% of pressure are lost comparing to a 60 Hz application. To meet these new market challenges, the Variable Frequency Drive (VFD) multistage centrifugal blower was designed, where the VFD serves not only as speed adjusting device to maximise the efficiency but also as a speed increaser to minimise the blower size. For existing WWTP installations, retrofit to a VFD drive requires minimum investment and leadtime while achieving drastic energy savings. A comparison with the gear drive high-speed single stage blower concept is also made. (Author)

  9. Optimization Strategies for Single-Stage, Multi-Stage and Continuous ADRs

    Science.gov (United States)

    Shirron, Peter J.

    2014-01-01

    Adiabatic Demagnetization Refrigerators (ADR) have many advantages that are prompting a resurgence in their use in spaceflight and laboratory applications. They are solid-state coolers capable of very high efficiency and very wide operating range. However, their low energy storage density translates to larger mass for a given cooling capacity than is possible with other refrigeration techniques. The interplay between refrigerant mass and other parameters such as magnetic field and heat transfer points in multi-stage ADRs gives rise to a wide parameter space for optimization. This paper first presents optimization strategies for single ADR stages, focusing primarily on obtaining the largest cooling capacity per stage mass, then discusses the optimization of multi-stage and continuous ADRs in the context of the coordinated heat transfer that must occur between stages. The goal for the latter is usually to obtain the largest cooling power per mass or volume, but there can also be many secondary objectives, such as limiting instantaneous heat rejection rates and producing intermediate temperatures for cooling of other instrument components.

  10. Simulation and analysis of multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine enantiomers☆

    Institute of Scientific and Technical Information of China (English)

    Ping Wen; Kewen Tang; Jicheng Zhou; Panliang Zhang

    2015-01-01

    Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid–liquid extraction model has been established to analyze and discuss on multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine (PGL) enantiomers. The influence of phase ratio, extractant concentra-tion, and PF6−concentration on the concentrations of enantiomers in the extract and raffinate was investigated by experiment and simulation. A good agreement between model and experiment was obtained. On this basis, the influence of many parameters such as location of stage, concentration levels, extractant excess, and number of stages on the symmetric separation performance was simulated. The optimal location of feed stage is the middle of fractional extraction equipment. The feed flow must satisfy a restricted relationship on flow ratios and the liquid throughout of centrifugal device. For desired purity specification, the required flow ratios decrease with extractant concentration and increase with PF6−concentration. When the number of stages is 18 stages at extractant excess of 1.0 or 14 stages at extractant excess of 2.0, the eeeq (equal enantiomeric excess) can reach to 99%.

  11. Lab-testing, predicting, and modeling multi-stage activated carbon adsorption of organic micro-pollutants from treated wastewater.

    Science.gov (United States)

    Zietzschmann, F; Altmann, J; Hannemann, C; Jekel, M

    2015-10-15

    Multi-stage reuse of powdered activated carbon (PAC) is often applied in practice for a more efficient exploitation of the PAC capacity to remove organic micro-pollutants (OMP). However, the adsorption mechanisms in multi-stage PAC reuse are rarely investigated, as large-scale experiments do not allow for systematic tests. In this study, a laboratory method for the separation of PAC/water suspensions and the subsequent reuse of the PAC and the water was developed. The method was tested on wastewater treatment plant (WWTP) effluent in a setup with up to 7 PAC reuse stages. The tests show that the overall OMP removal from WWTP effluent can be increased when reusing PAC. The reason is that a repeated adsorption in multi-stage PAC reuse results in similar equilibrium concentrations as a single-stage adsorption. Thus, a single relationship between solid and liquid phase OMP concentrations appears valid throughout all stages. This also means that the adsorption efficiency of multi-stage PAC reuse setups can be estimated from the data of a single-stage setup. Furthermore, the overall OMP removals in multi-stage setups coincide with the overall UV254 removals, and for each respective OMP one relationship to UV254 removal is valid throughout all stages. The results were modeled by a simple modification of the equivalent background compound model (EBCM) which was also used to simulate the additional OMP removals in multi-stage setups with up to 50 reuse stages. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Multistage stereotactic radiosurgery for large cerebral arteriovenous malformations using the Gamma Knife platform.

    Science.gov (United States)

    Ding, Chuxiong; Hrycushko, Brian; Whitworth, Louis; Li, Xiang; Nedzi, Lucien; Weprin, Bradley; Abdulrahman, Ramzi; Welch, Babu; Jiang, Steve B; Wardak, Zabi; Timmerman, Robert D

    2017-07-06

    Radiosurgery is an established technique to treat cerebral arteriovenous malformations (AVMs). Obliteration of larger AVMs (> 10-15 cm(3) or diameter > 3 cm) in a single session is challenging with current radiosurgery platforms due to toxicity. We present a novel technique of multistage stereotactic radiosurgery (SRS) for large intracranial arteriovenous malformations (AVM) using the Gamma Knife system. Eighteen patients with large (> 10-15 cm(3) or diameter > 3 cm) AVMs, which were previously treated using a staged SRS technique on the Cyberknife platform, were retrospectively selected for this study. The AVMs were contoured and divided into 3-8 subtargets to be treated sequentially in a staged approach at half to 4 week intervals. The prescription dose ranged from 15 Gy to 20 Gy, depending on the subtarget number, volume, and location. Gamma Knife plans using multiple collimator settings were generated and optimized. The coordinates of each shot from the initial plan covering the total AVM target were extracted based on their relative positions within the frame system. The shots were regrouped based on their location with respect to the subtarget contours to generate subplans for each stage. The delivery time of each shot for a subtarget was decay corrected with (60) Co for staging the treatment course to generate the same dose distribution as that planned for the total AVM target. Conformality indices and dose-volume analysis were performed to evaluate treatment plans. With the shot redistribution technique, the composite dose for the multistaged treatment of multiple subtargets is equivalent to the initial plan for total AVM target. Gamma Knife plans resulted in an average PTV coverage of 96.3 ± 0.9% and a PITV of 1.23 ± 0.1. The resulting Conformality indices, V12Gy and R50 dose spillage values were 0.76 ± 0.05, 3.4 ± 1.8, and 3.1 ± 0.5 respectively. The Gamma Knife system can deliver a multistaged conformal dose to treat large AVMs when correcting for

  13. Multi-stage full waveform inversion strategy for 2D elastic VTI media

    KAUST Repository

    Oh, Ju-Won

    2015-08-19

    One of the most important issues in the multi-parametric full waveform inversion (FWI) is to find an optimal parameterization, which helps us recover the subsurface anisotropic parameters as well as seismic velocities, with minimal tradeoff. As a result, we analyze three different parameterizations for elastic VTI media in terms of the influence of the S-waves on the gradient direction for c13, the spatial coverage of gradient direction and the degree of trade-offs between the parameters. Based on the dependency results, we design a multi-stage elastic VTI FWI strategy to enhance both the spatial coverage of the FWI and the robustness to the trade-offs among the parameters as well as FWI for the c13 structure.

  14. Optimization of Adaboost Algorithm for Sonar Target Detection in a Multi-Stage ATR System

    Science.gov (United States)

    Lin, Tsung Han (Hank)

    2011-01-01

    JPL has developed a multi-stage Automated Target Recognition (ATR) system to locate objects in images. First, input images are preprocessed and sent to a Grayscale Optical Correlator (GOC) filter to identify possible regions-of-interest (ROIs). Second, feature extraction operations are performed using Texton filters and Principal Component Analysis (PCA). Finally, the features are fed to a classifier, to identify ROIs that contain the targets. Previous work used the Feed-forward Back-propagation Neural Network for classification. In this project we investigate a version of Adaboost as a classifier for comparison. The version we used is known as GentleBoost. We used the boosted decision tree as the weak classifier. We have tested our ATR system against real-world sonar images using the Adaboost approach. Results indicate an improvement in performance over a single Neural Network design.

  15. Application of Multistage Homotopy Perturbation Method to the Chaotic Genesio System

    Directory of Open Access Journals (Sweden)

    M. S. H. Chowdhury

    2012-01-01

    Full Text Available Finding accurate solution of chaotic system by using efficient existing numerical methods is very hard for its complex dynamical behaviors. In this paper, the multistage homotopy-perturbation method (MHPM is applied to the Chaotic Genesio system. The MHPM is a simple reliable modification based on an adaptation of the standard homotopy-perturbation method (HPM. The HPM is treated as an algorithm in a sequence of intervals for finding accurate approximate solutions to the Chaotic Genesio system. Numerical comparisons between the MHPM and the classical fourth-order Runge-Kutta (RK4 solutions are made. The results reveal that the new technique is a promising tool for the nonlinear chaotic systems of ordinary differential equations.

  16. A Palaeoproterozoic multi-stage hydrothermal alteration system at Nalunaq gold deposit, South Greenland

    DEFF Research Database (Denmark)

    Bell, Robin-Marie; Kolb, Jochen; Waight, Tod Earle

    2017-01-01

    closure in 2014, having produced 10.67 t of gold. This study uses a combination of field investigation, petrography and U/Pb zircon and titanite geochronology to define a multistage hydrothermal alteration system at Nalunaq. A clinopyroxene-plagioclase-garnet(-sulphide) alteration zone (CPGZ) developed...... in the Nanortalik Peninsula, close to regional peak metamorphism and prior to gold-quartz vein formation. The ca. 1783–1762-Ma gold-quartz veins are hosted in reactivated shear zones with a hydrothermal alteration halo of biotite-arsenopyrite-sericite-actinolite-pyrrhotite(-chloriteplagioclase- löllingite......-tourmaline-titanite), which is best developed in areas of exceptionally high gold grades. Aplite dykes dated to ca. 1762 Ma cross-cut the gold-quartz veins, providing a minimum age for mineralisation. A hydrothermal calcite-titanite alteration assemblage is dated to ca. 1766 Ma; however, this alteration is highly isolated...

  17. Performance Study of Multilayered Multistage Interconnection Networks under Hotspot Traffic Conditions

    Directory of Open Access Journals (Sweden)

    Dimitris Vasiliadis

    2010-01-01

    Full Text Available The performance of Multistage Interconnection Networks (MINs under hotspot traffic, where some percentage of the traffic is targeted at single nodes, which are also called hot spots, is of crucial interest. The prioritizing of packets has already been proposed at previous works as alleviation to the tree saturation problem, leading to a scheme that natively supports 2-class priority traffic. In order to prevent hotspot traffic from degrading uniform traffic we expand previous studies by introducing multilayer Switching Elements (SEs at last stages in an attempt to balance between MIN performance and cost. In this paper the performance evaluation of dual-priority, double-buffered, multilayer MINs under single hotspot setups is presented and analyzed using simulation experiments. The findings of this paper can be used by MIN designers to optimally configure their networks.

  18. A multistage, semi-automated procedure for analyzing the morphology of nanoparticles

    KAUST Repository

    Park, Chiwoo

    2012-07-01

    This article presents a multistage, semi-automated procedure that can expedite the morphology analysis of nanoparticles. Material scientists have long conjectured that the morphology of nanoparticles has a profound impact on the properties of the hosting material, but a bottleneck is the lack of a reliable and automated morphology analysis of the particles based on their image measurements. This article attempts to fill in this critical void. One particular challenge in nanomorphology analysis is how to analyze the overlapped nanoparticles, a problem not well addressed by the existing methods but effectively tackled by the method proposed in this article. This method entails multiple stages of operations, executed sequentially, and is considered semi-automated due to the inclusion of a semi-supervised clustering step. The proposed method is applied to several images of nanoparticles, producing the needed statistical characterization of their morphology. © 2012 "IIE".

  19. Multistage depressed collector conceptual design for thin magnetically confined electron beams

    Science.gov (United States)

    Pagonakis, Ioannis Gr.; Wu, Chuanren; Illy, Stefan; Jelonnek, John

    2016-04-01

    The requirement of higher efficiency in high power microwave devices, such as traveling wave tubes and gyrotrons, guides scientific research to more advanced types of collector systems. First, a conceptual design approach of a multistage depressed collector for a sheet electron beam confined by a magnetic field is presented. The sorting of the electron trajectories, according to their initial kinetic energy, is based on the E × B drift concept. The optimization of the geometrical parameters is based on the analytical equations under several general assumptions. The analysis predicts very high levels of efficiency. Then, a design approach for the application of this type of collector to a gyrotron cylindrical hollow electron beam is also presented with very high levels of efficiency more than 80%.

  20. Multi-stage drying of PVA aqueous solution film; PVA suiyoeki no bunri tofu kanso

    Energy Technology Data Exchange (ETDEWEB)

    Kishi, M.; Inoue, S. [Dai Nippon Printing Co. Ltd., Tokyo (Japan); Imakawa, H. [Kobe University, Kobe (Japan), Faculty of Engineering; Okazaki, M. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1995-07-10

    In a multi-stage coating and drying process, in which PVA (Polyvinyl alcohol) film was formed by repeating twice a set of operations consisting of coating PVA aqueous solution and convective drying of it, the drying process was numerically simulated using a drying model based on mass transfer within a coated film. The possibility of minimizing drying time was also investigated. Total drying time, summed over the first and second stages, required to yield a target mean moisture concentration in the solution film was calculated while changing the final mean moisture concentration of the first stage. It was found that the minimum drying time appeared for each target concentration and the effect of reduction on the total drying time became significant with increasing target concentration. 12 refs., 5 figs., 1 tab.

  1. Numerical investigation of flow through vegetated multi-stage compound cha-nnel

    Institute of Scientific and Technical Information of China (English)

    王雯; 槐文信; 高猛

    2014-01-01

    This paper addresses the problem of the renormalization group k-e turbulence modeling of a vegetated multi-stage compound channel. Results from Micro acoustic Doppler velocimeter (ADV) tests are used with time and spatial averaging (double-averaging method) in the analysis of the flow field and the characterization. Comparisons of the mean velocity, the Reynolds stress, and the turbulent energy distribution show the validity of the computational method. The mean velocity profile sees an obvious de-celeration in the terraces because of vegetation. Secondary flow exists mainly at the junction of the main channel and the vegetation region on the first terrace. The bed shear stress in the main channel is much greater than that in the terraces. The difference of the bed shear stress between two terraces is insignificant, and the presence of vegetation can effectively reduce the bed shear stress.

  2. Beneath Still Waters - Multistage Aquatic Exploitation of Euryale ferox (Salisb. during the Acheulian

    Directory of Open Access Journals (Sweden)

    Naama Goren-Inbar1

    2014-09-01

    Full Text Available Remains of the highly nutritious aquatic plant Fox nut – Euryale ferox Salisb. (Nymphaeaceae – were found at the Acheulian site of Gesher Benot Ya'aqov, Israel. Here, we present new evidence for complex cognitive strategies of hominins as seen in their exploitation of E. ferox nuts. We draw on excavated data and on parallels observed in traditional collecting and processing practices from Bihar, India. We suggest that during the early Middle Pleistocene, hominins implemented multistage procedures comprising underwater gathering and subsequent processing (drying, roasting and popping of E. ferox nuts. Hierarchical processing strategies are observed in the Acheulian lithic reduction sequences and butchering of game at this and other sites, but are poorly understood as regards the exploitation of aquatic plant resources. We highlight the ability of Acheulian hominins to resolve issues related to underwater gathering of E. ferox nuts during the plant's life cycle and to adopt strategies to enhance their nutritive value.

  3. Shortcut Design Method for Multistage Binary Distillation via MS-Excel

    Directory of Open Access Journals (Sweden)

    Mr. S. B. Dongare

    2016-10-01

    Full Text Available Multistage distillation is most widely used industrial method for separating chemical mixtures with high energy consumptions especially when relative volatility of key components is lower than 1.5. The McCabe Thiele is considered to be the simplest and perhaps most instructive method for the conceptual design of binary distillation column which is still widely used, mainly for quick preliminary calculations. In this present work, we provide a numerical solution to a McCabe-Thiele method to find out theoretical number of stages for ideal and non-ideal binary system, reflux ratio, condenser duty, reboiler duty, each plate composition inside the column. Each and every point related to McCabe-Thiele in MS-Excel to give quick column dimensions are discussed in details

  4. In situ crosslinked smart polypeptide nanoparticles for multistage responsive tumor-targeted drug delivery

    Science.gov (United States)

    Yi, Huqiang; Liu, Peng; Sheng, Nan; Gong, Ping; Ma, Yifan; Cai, Lintao

    2016-03-01

    Smart tumor-targeted drug delivery is crucial for improving the effect of chemotherapy and reducing the adverse effects. Here, we synthesized a smart polypeptide copolymer based on n-butylamine-poly(l-lysine)-b-poly(l-cysteine) (PLL-PLC) with functionalization of folic acid (FA) and 1,2-dicarboxylic-cyclohexene anhydride (DCA) for multistage responsive tumor-targeted drug delivery. The copolymers (FA-PLL(DCA)-PLC) spontaneously crosslinked in situ to form redox and pH dual responsive FA-PLL(DCA)-PLC nanoparticles (FD-NPs), which had a reversible zeta potential around -30 mV at pH 7.4, but switched to +15 mV at pH 5.0. Moreover, FD-NPs effectively loaded DOX with a loading capacity at 15.7 wt%. At pH 7.4, only 24.5% DOX was released within 60 h. However, at pH 5.0, the presence of 10 mM DTT dramatically accelerated DOX release with over 90% of DOX released within 10 h. Although the FD-NPs only enhanced DOX uptake in FA receptor positive (FR+) cancer cells at pH 7.4, a weak acidic condition promoted FD-NP-facilitated DOX uptake in both FR+ HeLa and FR- A549 cells, as well as significantly improving cellular binding and end/lysosomal escape. In vivo studies in a HeLa cancer model demonstrated that the charge-reversible FD-NPs delivered DOX into tumors more effectively than charge-irreversible nanoparticles. Hence, these multistage responsive FD-NPs would serve as highly efficient drug vectors for targeted cancer chemotherapy.Smart tumor-targeted drug delivery is crucial for improving the effect of chemotherapy and reducing the adverse effects. Here, we synthesized a smart polypeptide copolymer based on n-butylamine-poly(l-lysine)-b-poly(l-cysteine) (PLL-PLC) with functionalization of folic acid (FA) and 1,2-dicarboxylic-cyclohexene anhydride (DCA) for multistage responsive tumor-targeted drug delivery. The copolymers (FA-PLL(DCA)-PLC) spontaneously crosslinked in situ to form redox and pH dual responsive FA-PLL(DCA)-PLC nanoparticles (FD-NPs), which had a reversible

  5. Effects of gear box vibration and mass imbalance on the dynamics of multistage gear transmission

    Science.gov (United States)

    Choy, F. K.; Tu, Y. K.; Zakrajsek, J. J.; Townsend, D. P.

    1991-01-01

    The dynamic behavior of multistage gear transmission system, with the effects of gear-box-induced vibrations and rotor mass-imbalances is analyzed. The model method, using undamped frequencies and planar mode shapes, is used to reduce the degree-of-freedom of the system. The various rotor-bearing stages as well as lateral and torsional vibrations of each individual stage are coupled through localized gear-mesh-tooth interactions. Gear-box vibrations are coupled to the gear stage dynamics through bearing support forces. Transient and steady state dynamics of lateral and torsional vibrations of the geared system are examined in both time and frequency domain. A typical three-staged geared system is used as an example. Effects of mass-imbalance and gear box vibrations on the system dynamic behavior are presented in terms of modal excitation functions for both lateral and torsional vibrations. Operational characteristics and conclusions are drawn from the results presented.

  6. Multi-stage continuous high cell density culture systems: a review.

    Science.gov (United States)

    Chang, Ho Nam; Jung, Kwonsu; Choi, Jin-Dal-Rae; Lee, Joon Chul; Woo, Hee-Chul

    2014-01-01

    A multi-stage continuous high cell density culture (MSC-HCDC) system makes it possible to achieve high productivity together with high product titer of many bioproducts. For long-term continuous operation of MSC-HCDC systems, the cell retention time and hydraulic retention time must be decoupled and strains (bacteria, yeast, plant, and animal cells) must be stable. MSC-HCDC systems are suitable for low-value high-volume extracellular products such as fuel ethanol, lactic acid or volatile fatty acids, and high-value products such as monoclonal antibodies as well as intracellular products such as polyhydroxybutyric acid (PHB), microbial lipids or a number of therapeutics. Better understanding of the fermentation kinetics of a specific product and reliable high-density culture methods for the product-generating microorganisms will facilitate timely industrialization of MSC-HCDC systems for products that are currently obtained in fed-batch bioreactors.

  7. Determination of salvinorins and divinatorins in Salvia divinorum leaves by liquid chromatography/multistage mass spectrometry.

    Science.gov (United States)

    Medana, Claudio; Massolino, Cristina; Pazzi, Marco; Baiocchi, Claudio

    2006-01-01

    Salvinorin A is the most potent naturally occurring hallucinogen known and rivals synthetic LSD in potency. Structurally it belongs to the neoclerodane diterpenoids, and it is the only known non-nitrogenous kappa-opioid-selective agonist. Salvia divinorum (Diviner's sage) is a member of the mint family that was used in ancient Mexican traditional practices. Today it is widely cultivated in Europe as a recreational marijuana substitute; it is illegal to buy, sell or possess the plant or the active principle in some countries. Six different salvinorins and three divinatorins have been isolated from Salvia divinorum leaves. The ion fragmentation, separation and quantitation of these diterpenes by liquid chromatography/electrospray ionization multistage mass spectrometry (LC/ESI-MS(n)) are described. The importance of LC in herbal extract determination and the chemical diagnostic power of MS(n) in the analysis of classes of natural organic products are discussed.

  8. Multi-Stage Admission Control for Load Balancing in Next Generation Systems

    DEFF Research Database (Denmark)

    Mihovska, Albena D.; Anggorojati, Bayu; Luo, Jijun;

    2008-01-01

    This paper describes a load-dependent multi-stage admission control suitable for next generation systems. The concept uses decision polling in entities located at different levels of the architecture hierarchy and based on the load to activate a sequence of actions related to the admission...... of a user to the network, i.e., the ranking of the intermediate decisions is dynamic. The decision is controlled by passing a token between the base station (BS) and the gateway (GW), thereby considering the load status of the BS and the backhaul network. A token is assigned to the entity with the highest...... load. Each admission request will issue a flag whose colour will reflect the load level in this entity and will determine the correct sequence of the required admission control actions....

  9. Generation of High Pressure Oxygen via Electrochemical Pumping in a Multi-stage Electrolysis Stack

    Science.gov (United States)

    Setlock, John A (Inventor); Green, Robert D (Inventor); Farmer, Serene (Inventor)

    2016-01-01

    An oxygen pump can produce high-purity high-pressure oxygen. Oxygen ions (O.sup.2-) are electrochemically pumped through a multi-stage electrolysis stack of cells. Each cell includes an oxygen-ion conducting solid-state electrolyte between cathode and anode sides. Oxygen dissociates into the ions at the cathode side. The ions migrate across the electrolyte and recombine at the anode side. An insulator is between adjacent cells to electrically isolate each individual cell. Each cell receives a similar volt potential. Recombined oxygen from a previous stage can diffuse through the insulator to reach the cathode side of the next stage. Each successive stage similarly incrementally pressurizes the oxygen to produce a final elevated pressure.

  10. Solar Multi-stage Refrigeration Systems on the Basis of Absorber with the Internal Evaporative Cooling

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2015-08-01

    Full Text Available In the article, the developed schematics are presented for the alternative refrigeration systems and air-conditioning systems, based on the use of absorbing cycle and solar energy for the regeneration of absorbent solution. Multi-stage principle of construction of drying and cool contours of solar systems is used with growth of concentration of absorbent on the stages of cooler. An absorber with internal evaporative cooling, allowing to remove the separate evaporated cooler, usually included after the absorber of the proper stage, is developed. Heat-mass-transfer apparatus of film-type, entering in the complement of drying and cool contours compatible and executed on the basis of multichannel compositions from polymeric materials. The preliminary comparative analysis of possibilities of the solar refrigeration systems and air-conditioning systems is executed.

  11. Detailed molecular characterization of castor oil ethoxylates by liquid chromatography multistage mass spectrometry.

    Science.gov (United States)

    Nasioudis, Andreas; van Velde, Jan W; Heeren, Ron M A; van den Brink, Oscar F

    2011-10-07

    The molecular characterization of castor oil ethoxylates (CASEOs) was studied by reverse-phase liquid chromatography (RPLC) mass spectrometry (MS) and multistage mass spectrometry (MS(n)). The developed RPLC method allowed the separation of the various CASEO components, and especially, the baseline separation of multiple nominal isobars (same nominal mass) and isomers (same exact mass). MS and MS(n) were used for the determination and structure elucidation of various structures and for the discrimination of the isobars and isomers. Different ionization techniques and adduct ions were also tested for optimization of the MS detection and the MS(n) fragmentation. A unique fragmentation pathway of ricinoleic acid is proposed, which can be used as a marker of the polymerization process and the topology of ethoxylation in the CASEO. In addition, characteristic neutral losses of ricinoleic acid reveal its (terminal or internal) position in the molecule.

  12. A model for calculating a.c. losses in multistage superconducting cables

    Science.gov (United States)

    Schild, T.; Ciazynski, D.

    Superconducting magnets in tokamaks for fusion experiments are subjected to fast variations in magnetic field. As the high current conductors used in these magnets are made of multistage cables, these variations induce interstrand coupling currents that create losses. These losses are usually characterized by the so-called time constant of the conductor. A model is given to calculate this time constant. Working formulas are also proposed to calculate the current induced in the different cabling stages. This model takes into account the strand characteristics and the detailed cabling pattern. Using it, a method is also given to deduce the time constant from resistive measurements. The influence of the resistive barrier (chrome plating, CuNi shell, outer bronze matrix) is pointed out. Finally, this model is applied to a conductor that is foreseen for the toroidal coils of the International Thermonuclear Experimental Reactor (ITER).

  13. Effect of a multistage ultraendurance triathlon on aldosterone, vasopressin, extracellular water and urine electrolytes.

    Science.gov (United States)

    Knechtle, B; Morales, N P Hernández; González, E Ruvalcaba; Gutierrez, A A Aguirre; Sevilla, J Noriega; Gómez, R Amézquita; Robledo, A R Estrada; Rodríguez, A L Marroquín; Fraire, O Salas; Andonie, J L; Lopez, L C; Kohler, G; Rosemann, T

    2012-02-01

    Prolonged endurance exercise over several days induces increase in extracellular water (ECW). We aimed to investigate an association between the increase in ECW and the change in aldosterone and vasopressin in a multistage ultraendurance triathlon, the 'World Challenge Deca Iron Triathlon' with 10 Ironman triathlons within 10 days. Before and after each Ironman, body mass, ECW, urinary [Na(+)], urinary [K(+)], urinary specific gravity, urinary osmolality and aldosterone and vasopressin in plasma were measured. The 11 finishers completed the total distance of 38 km swimming, 1800 km cycling and 422 km running within 145.5 (18.8) hours and 25 (22) minutes. ECW increased by 0.9 (1.1) L from 14.6 (1.5) L prerace to 15.5 (1.9) L postrace (P triathlon, but vasopressin did not. The increase in ECW and the increase in aldosterone were not associated.

  14. Concept of Powerful Multistage Coaxial Cyclotron for Pulsed and Continuous Beam Production

    CERN Document Server

    Tumanyan, A R; Guiragossian, Z G T; Akopov, N Z

    1999-01-01

    The concept of large-radius multistage coaxial cyclotrons having separated orbits is described, to generate proton beams of 120-2000 MeV energy at tens of GW pulsed and hundreds of MW in continuous beam power operation. Accelerated beam losses must be less than 0.1 W/m for the intercepted average beam power linear density. The concept is inherently configured to actively compensate the longitudinal and transverse space charge expansion in beam bunches. These are based on (1) actively varying the bunch acceleration equilibrium phase while maintaining isochronism, independently for each cyclotron turns; (2) independently changing the acceleration voltage for each turn together with orbit corrections that preserve isochronism; (3) independently changing the transverse betatron oscillation tune shift, to assure non-resonant operation. Also, (4) sextupole lenses are included to compensate for chromaticity effects. Moreover, the concept is based on optimum uses of practical successful results so far achieved in bea...

  15. SOLAR ABSORBING COOLING SYSTEMS BASED ON MULTISTAGE HEAT-MASS-TRANSFER DEVICES

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2014-08-01

    Full Text Available The article presents the worked out schematics for the alternative refrigeration systems and of air-conditioning systems, based on the use of absorbing cycle and of the sunny energy for the regeneration (renewals of absorbent solution. We use here the cascade principle of construction of all heat-mass-transfer apparatus with variation of both the temperature level and the growth of absorbent concentration on the cascade stages. The heat-mass-transfer equipment as a part of the drying and cooling units is standardized and is executed by means of multistage monoblock compositions from poly-meric materials. The preliminary analysis of possibilities of the sunny systems in application to the tasks of cooling of environment and air-conditioning systems is carried out.

  16. Optimal design of multistage chemostats in series using different microbial growth kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Qasim, Muhammad [Petroleum Engineering Technology, Abu Dhabi Polytechnic (United Arab Emirates)

    2013-07-01

    In this paper, the optimum design of multistage chemostats (CSTRs) was investigated. The optimal design was based on the minimum overall reactor volume using different volume for each chemostat. The paper investigates three different microbial growth kinetics; Monod kinetics, Contois kinetics and the Logistic equation. The total dimensionless residence time (theta Total) was set as the optimization objective function that was minimized by varying the intermediate dimensionless substrate concentration (alfa i). The effect of inlet substrate concentration (S0) to the first reactor on the optimized total dimensionless residence time was investigated at a constant conversion of 0.90. In addition, the effect of conversion on the optimized total dimensionless residence time was also investigated at constant inlet substrate concentration (S0). For each case, optimization was done using up to five chemostats in series.

  17. Multipurpose speech watermarking based on multistage vector quantization of linear prediction coefficients

    Institute of Scientific and Technical Information of China (English)

    CHEN Ning; ZHU Jie

    2007-01-01

    To make speech watermarking achieve both copyright protection and integrity verification, a novel multipurpose speech watermarking algorithm based on the multistage vector quantization (MSVQ) of linear prediction coefficients (LPCs) is presented in this article. The property of natural speech that the vector quantization (VQ) indices of the LPCs amongst neigh- boring frames tend to be very similar is utilized to embed the robust watermark in the indices of the first-stage VQ (VQ1). Then, the semi-fragile watermark is embedded in the indices of the second-stage VQ (VQ2) with index constrained VQ encoding scheme. Both the robust watermark and the semi-fragile water- mark can be extracted without host speech. Simulation results verify the effectiveness of the proposed algorithm in terms of robustness and semi-fragility.

  18. A multistage coordinative optimization for sitting and sizing P2G plants in an integrated electricity and natural gas system

    DEFF Research Database (Denmark)

    Zeng, Q.; Fang, J.; Chen, Z.

    2016-01-01

    sited and sized in the integrated energy system. The problem model is formulated as a multi-stage integer nonlinear optimization. The objective is to minimize the investment plus operation costs by determining the optimal location, capacity, and installation time of P2G. Case studies are simulated...

  19. A bi-level programming for multistage co-expansion planning of the integrated gas and electricity system

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    power systems. The system operation is optimized and embedded in the planning horizon. A bi-level multi-stage programming problem is formulated to minimize the investment cost plus the operational cost. The upper-level optimizes the expansion plan and determines the network topology as well...

  20. FLOW REGIMES, GAS HOLD-UP AND AXIAL GAS MIXING IN THE GAS-LIQUID MULTISTAGE AGITATED CONTACTOR

    NARCIS (Netherlands)

    BREMAN, BB; BEENACKERS, AACM; BOUMA, MJ

    1995-01-01

    Experimental data are reported on Row regimes, gas hold-up and axial gas mixing of a gas-liquid Multi-stage Agitated Contactor (MAC), consisting of nine compartments [height, H, over diameter, D = 1; D = 0.09 m) separated by horizontal baffles with an opening of 0.04 m and with one centrally positio

  1. Suicide Prevention among High School Students: Evaluation of a Nonrandomized Trial of a Multi-Stage Suicide Screening Program

    Science.gov (United States)

    Torcasso, Gina; Hilt, Lori M.

    2017-01-01

    Background: Suicide is a leading cause of death among youth. Suicide screening programs aim to identify mental health issues and prevent death by suicide. Objective: The present study evaluated outcomes of a multi-stage screening program implemented over 3 school years in a moderately-sized Midwestern high school. Methods: One hundred ninety-three…

  2. Simplified Multi-Stage and Per Capita Convergence: an analysis of two climate regimes for differentiation of commitments

    NARCIS (Netherlands)

    Elzen MGJ den; Berk MM; Lucas P; KMD

    2004-01-01

    Dit rapport beschrijft een analyse van twee post-Kyoto regimes voor lastenverdeling in het internationale klimaatbeleid: 1. de Multi-stage benadering, waarbij landen op grond van hoofdelijk inkomen en emissies worden ingedeeld in groepen met verschillende typen van doelstellingen (stadia). 2. de

  3. Suicide Prevention among High School Students: Evaluation of a Nonrandomized Trial of a Multi-Stage Suicide Screening Program

    Science.gov (United States)

    Torcasso, Gina; Hilt, Lori M.

    2017-01-01

    Background: Suicide is a leading cause of death among youth. Suicide screening programs aim to identify mental health issues and prevent death by suicide. Objective: The present study evaluated outcomes of a multi-stage screening program implemented over 3 school years in a moderately-sized Midwestern high school. Methods: One hundred ninety-three…

  4. Genomic Analysis Reveals Disruption of Striatal Neuronal Development and Therapeutic Targets in Human Huntington’s Disease Neural Stem Cells

    Directory of Open Access Journals (Sweden)

    Karen L. Ring

    2015-12-01

    Full Text Available We utilized induced pluripotent stem cells (iPSCs derived from Huntington’s disease (HD patients as a human model of HD and determined that the disease phenotypes only manifest in the differentiated neural stem cell (NSC stage, not in iPSCs. To understand the molecular basis for the CAG repeat expansion-dependent disease phenotypes in NSCs, we performed transcriptomic analysis of HD iPSCs and HD NSCs compared to isogenic controls. Differential gene expression and pathway analysis pointed to transforming growth factor β (TGF-β and netrin-1 as the top dysregulated pathways. Using data-driven gene coexpression network analysis, we identified seven distinct coexpression modules and focused on two that were correlated with changes in gene expression due to the CAG expansion. Our HD NSC model revealed the dysregulation of genes involved in neuronal development and the formation of the dorsal striatum. The striatal and neuronal networks disrupted could be modulated to correct HD phenotypes and provide therapeutic targets.

  5. Genomic Analysis Reveals Disruption of Striatal Neuronal Development and Therapeutic Targets in Human Huntington's Disease Neural Stem Cells.

    Science.gov (United States)

    Ring, Karen L; An, Mahru C; Zhang, Ningzhe; O'Brien, Robert N; Ramos, Eliana Marisa; Gao, Fuying; Atwood, Robert; Bailus, Barbara J; Melov, Simon; Mooney, Sean D; Coppola, Giovanni; Ellerby, Lisa M

    2015-12-08

    We utilized induced pluripotent stem cells (iPSCs) derived from Huntington's disease (HD) patients as a human model of HD and determined that the disease phenotypes only manifest in the differentiated neural stem cell (NSC) stage, not in iPSCs. To understand the molecular basis for the CAG repeat expansion-dependent disease phenotypes in NSCs, we performed transcriptomic analysis of HD iPSCs and HD NSCs compared to isogenic controls. Differential gene expression and pathway analysis pointed to transforming growth factor β (TGF-β) and netrin-1 as the top dysregulated pathways. Using data-driven gene coexpression network analysis, we identified seven distinct coexpression modules and focused on two that were correlated with changes in gene expression due to the CAG expansion. Our HD NSC model revealed the dysregulation of genes involved in neuronal development and the formation of the dorsal striatum. The striatal and neuronal networks disrupted could be modulated to correct HD phenotypes and provide therapeutic targets.

  6. Reversibility of cellular aging by reprogramming through an embryonic-like state : a new paradigm for human cell rejuvenation

    Directory of Open Access Journals (Sweden)

    Jean-Marc Lemaitre

    2014-01-01

    Full Text Available Direct reprogramming of somatic cells into induced pluripotent stem cells (iPSCs provides a unique opportunity to derive patient-specific stem cells with potential application in autologous tissue replacement therapies and without the ethical concerns of Embryonic Stem Cells (hESC. However, this strategy still suffers from several hurdles that need to be overcome before clinical applications. Among them, cellular senescence, which contributes to aging and restricted longevity, has been described as a barrier to the derivation of iPSCs. This suggests that aging might be an important limitation for therapeutic purposes for elderly individuals. Senescence is characterized by an irreversible cell cycle arrest in response to various forms of stress, including activation of oncogenes, shortened telomeres, DNA damage, oxidative stress, and mitochondrial dysfunction. To overcome this barrier, we developed an optimized 6-factor-based reprogramming protocol that is able to cause efficient reversing of cellular senescence and reprogramming into iPSCs. We demonstrated that iPSCs derived from senescent and centenarian fibroblasts have reset telomere size, gene expression profiles, oxidative stress, and mitochondrial metabolism, and are indistinguishable from hESC. Finally, we demonstrate that re-differentiation led to rejuvenated cells with a reset cellular physiology, defining a new paradigm for human cell rejuvenation. We discuss the molecular mechanisms involved in cell reprogramming of senescent cells. 

  7. Regulation of the DNA Methylation Landscape in Human Somatic Cell Reprogramming by the miR-29 Family

    Directory of Open Access Journals (Sweden)

    Eriona Hysolli

    2016-07-01

    Full Text Available Reprogramming to pluripotency after overexpression of OCT4, SOX2, KLF4, and MYC is accompanied by global genomic and epigenomic changes. Histone modification and DNA methylation states in induced pluripotent stem cells (iPSCs have been shown to be highly similar to embryonic stem cells (ESCs. However, epigenetic differences still exist between iPSCs and ESCs. In particular, aberrant DNA methylation states found in iPSCs are a major concern when using iPSCs in a clinical setting. Thus, it is critical to find factors that regulate DNA methylation states in reprogramming. Here, we found that the miR-29 family is an important epigenetic regulator during human somatic cell reprogramming. Our global DNA methylation and hydroxymethylation analysis shows that DNA demethylation is a major event mediated by miR-29a depletion during early reprogramming, and that iPSCs derived from miR-29a depletion are epigenetically closer to ESCs. Our findings uncover an important miRNA-based approach to generate clinically robust iPSCs.

  8. Lumped-equivalent circuit model for multi-stage cascaded magnetoelectric dual-tunable bandpass filter

    Institute of Scientific and Technical Information of China (English)

    张秋实; 朱锋杰; 周浩淼

    2015-01-01

    A lumped-equivalent circuit model of a novel magnetoelectric tunable bandpass filter, which is realized in the form of multi-stage cascading between a plurality of magnetoelectric laminates, is established in this paper for convenient analysis. The multi-stage cascaded filter is degraded to the coupling microstrip filter with only one magnetoelectric laminate and then compared with the existing experiment results. The comparison reveals that the insertion loss curves predicted by the degraded circuit model are in good agreement with the experiment results and the predicted results of the electromagnetic field simulation, thus the validity of the model is verified. The model is then degraded to the two-stage cascaded magneto-electric filter with two magnetoelectric laminates. It is revealed that if the applied external bias magnetic or electric fields on the two magnetoelectric laminates are identical, then the passband of the filter will drift under the changed external field; that is to say, the filter has the characteristics of external magnetic field tunability and electric field tunability. If the applied external bias magnetic or electric fields on two magnetoelectric laminates are different, then the passband will disappear so that the switching characteristic is achieved. When the same magnetic fields are applied to the laminates, the passband bandwidth of the two-stage cascaded magnetoelectric filter with two magnetoelectric laminates becomes nearly doubled in comparison with the passband filter which contains only one magnetoelectric laminate. The bandpass effect is also improved obviously. This research will provide a theoretical basis for the design, preparation, and application of a new high performance magnetoelectric tunable microwave device.

  9. Functioning efficiency of intermediate coolers of multistage steam-jet ejectors of steam turbines

    Science.gov (United States)

    Aronson, K. E.; Ryabchikov, A. Yu.; Brodov, Yu. M.; Zhelonkin, N. V.; Murmanskii, I. B.

    2017-03-01

    Designs of various types of intermediate coolers of multistage ejectors are analyzed and thermal effectiveness and gas-dynamic resistance of coolers are estimated. Data on quantity of steam condensed from steam-air mixture in stage I of an ejector cooler was obtained on the basis of experimental results. It is established that the amount of steam condensed in the cooler constitutes 0.6-0.7 and is almost independent of operating steam pressure (and, consequently, of steam flow) and air amount in steam-air mixture. It is suggested to estimate the amount of condensed steam in a cooler of stage I based on comparison of computed and experimental characteristics of stage II. Computation taking this hypothesis for main types of mass produced multistage ejectors into account shows that 0.60-0.85 of steam amount should be condensed in stage I of the cooler. For ejectors with "pipe-in-pipe" type coolers (EPO-3-200) and helical coolers (EO-30), amount of condensed steam may reach 0.93-0.98. Estimation of gas-dynamic resistance of coolers shows that resistance from steam side in coolers with built-in and remote pipe bundle constitutes 100-300 Pa. Gas-dynamic resistance of "pipein- pipe" and helical type coolers is significantly higher (3-6 times) compared with pipe bundle. However, performance by "dry" (atmospheric) air is higher for ejectors with relatively high gas-dynamic resistance of coolers than those with low resistance at approximately equal operating flow values of ejectors.

  10. Nonlinear resonances in a multi-stage free-electron laser amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, S. [Graduate Univ. for Advanced Studies, Ibaraki-ken (Japan); Takayama, K. [National Lab. for High Energy Physics, Ibaraki-ken (Japan)

    1995-12-31

    A two-beam accelerator (TBA) is a possible candidate of future linear colliders, in which the demanded rf power is provided by a multi-stage free-electron laser (MFEL). After if amplification in each stage, a driving beam is re-accelerated by an induction unit and propagates into the next stage. Recently it has been recognized that the multi-stage character of the MFEL causes resonances between its periodicity and the synchrotron motion in an rf bucket. Since the synchrotron oscillation is strongly modulated by the resonance and at the worst a large fraction of particles is trapped in the resonance islands, the nonlinear resonances in the FEL longitudinal beam dynamics can lead to notable degradation of the MFEL performance, such as output fluctuation and phase modulation which have been big concerns in the accelerator society. The overall efficiency of the MFEL and the quality of the amplified microwave power are key issues for realizing the TBA/FEL Particularly the rf phase and amplitude errors must be maintained within tolerance. One of significant obstacles is an amplification of undesired modes. If a small-size waveguide is employed, the FEL resonance energies for undesired higher order modes shift very far from that for a fundamental mode; so it is possible to prevent higher order modes from evolving. Such a small-size waveguide, however, gives a high power density in the FEL. Simulation results have demonstrated that the nonlinear resonances occur in die FEL longitudinal motion when the power density exceeds some threshold. An analytical method for studying the nonlinear resonance in the TBA/FEL is developed based on the macroparticle model which can describe analytically the drastic behaviors in the evolutions of the phase and amplitude. In the theory the basic 1D-FEL equations are reduced to a nonlinear pendulum equation with respect to the ponderomotive phase.

  11. European dominance in multistage ultramarathons: an analysis of finisher rate and performance trends from 1992 to 2010

    Directory of Open Access Journals (Sweden)

    Abou Shoak M

    2013-01-01

    Full Text Available Mohannad Abou Shoak,1 Beat Knechtle,1,2 Christoph Alexander Rüst,1 Romuald Lepers,3 Thomas Rosemann11Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: Participation and performance trends regarding the nationality of ultraendurance athletes have been investigated in the triathlon, but not in running. The present study aimed to identify the countries in which multistage ultramarathons were held around the world and the nationalities of successful finishers.Methods: Finisher rates and performance trends of finishers in multistage ultramarathons held worldwide between 1992 and 2010 were investigated.Results: Between 1992 and 2010, the bulk of multistage ultramarathons were held in Germany and France, with more than 30 races organized in each country. Completion rates for men and women increased exponentially, with women representing on average 16.4% of the total field. Since 1992, 6480 athletes have competed in Morocco, 2538 in Germany, and 1842 in France. A total of 81.9% of athletes originated from Europe, and more specifically from France (22.9%, Great Britain (18.0%, and Germany (13.4%.Conclusion: European ultramarathoners dominated the athletes who completed multistage ultramarathons worldwide, with specific dominance of French, British, and German athletes. Future studies should investigate social aspects, such as sport tourism, among European athletes to understand why European athletes are so interested in participating in multistage ultramarathons.Keywords: ultraendurance, run, nationality, distance, stage

  12. Induced pluripotent stem cells (iPSCs) derived from a patient with frontotemporal dementia caused by a P301L mutation in microtubule-associated protein tau (MAPT)

    DEFF Research Database (Denmark)

    Rasmussen, Mikkel A.; Hjermind, Lena Elisabeth; Hasholt, Lis Frydenreich;

    2016-01-01

    Skin fibroblasts were obtained froma 57-year-old woman diagnosed with frontotemporal dementia. The diseaseis caused by a P301L mutation in microtubule-associated protein tau (MAPT). Induced pluripotent stem cells (iPSCs) were established by electroporation with episomal plasmids containing hOCT4, h......SOX2, hKLF2, hL-MYC,hLIN-28 and shP53. iPSCs were free of genomically integrated reprogramming genes, contained the expected c.902C>T substitution in exon 10 of the MAPT gene, expressed the expected pluripotency markers, displayed in vitro differentiation potential to the three germ layers and had...... normal karyotype. The iPSC line may be useful for studying hereditary frontotemporal dementia and TAU pathology in vitro....

  13. Induced pluripotent stem cells (iPSCs) derived from a patient with frontotemporal dementia caused by a R406W mutation in microtubule-associated protein tau (MAPT)

    DEFF Research Database (Denmark)

    Rasmussen, Mikkel A.; Hjermind, Lena E.; Hasholt, Lis F.

    2016-01-01

    Skin fibroblasts were obtained from a 59-year-old woman diagnosed with frontotemporal dementia. The disease is caused by a R406W mutation in microtubule-associated protein tau (MAPT). Induced pluripotent stem cells (iPSCs) were established by electroporation with episomal plasmids containing hOCT4...

  14. Induced pluripotent stem cells (iPSCs) derived from a patient with frontotemporal dementia caused by a P301L mutation in microtubule-associated protein tau (MAPT)

    DEFF Research Database (Denmark)

    Rasmussen, Mikkel A.; Hjermind, Lena Elisabeth; Hasholt, Lis Frydenreich

    2016-01-01

    Skin fibroblasts were obtained froma 57-year-old woman diagnosed with frontotemporal dementia. The diseaseis caused by a P301L mutation in microtubule-associated protein tau (MAPT). Induced pluripotent stem cells (iPSCs) were established by electroporation with episomal plasmids containing hOCT4, h...

  15. Were the Trænadjupet and Nyk Slides multi-staged?

    Science.gov (United States)

    Allin, Joshua; Mozzato, Alessandro; Tappin, David; Talling, Peter; Hunt, James

    2016-04-01

    Submarine landslides originating from active and extinct trough mouth fans are some of the largest single mass movements evident on Earth. These landslides are capable of damaging offshore infrastructure and can also trigger far-reaching tsunamis. For these reasons understanding the timing, dynamics, and triggering mechanisms of large submarine landslides is important for regional geohazard assessment. The Trænadjupet Slide occurred 4,000 ca. years ago and originated from the Trænadjupet paleo-ice stream on the Central Norwegian margin. The Trænadjupet Slide partially buried the deposits of a previous slide originating from the same section of the Norwegian margin; the Nyk Slide, which occurred at 16,000 ca years ago. Although the Trænadjupet Slide had an estimated volume of 900 km3 and originated from a shallow water depth, it does not appear to have triggered a tsunami. This is in contrast to the comparably-sized Storegga Slide, which produced a tsunami that devastated coastal areas as far away as Scotland. The apparent absence of a tsunami suggests that the failure dynamics for the Trænadjupet slide were different to that of other large slides along the Norwegian Margin. The deposits of both the Trænadjupet and Nyk Slides consist of several blocky lobes extending out into the Lofoten Basin. The lobate morphology of the deposits may imply that both slides occurred in a number of different and possibly temporally-disparate stages. Importantly, multi-staged failures have a much lower tsunamigenic potential due to the lower initial volume displacement. These staggered failures consisting of smaller sediment volumes might explain why no contemporaneous onshore tsunami deposits are found on nearby coastlines, particularly in the case of the post-glacial Trænadjupet Slide. Here we present a new sediment core dataset collected from the previously un-sampled lobes of the Trænadjupet and Nyk Slides. These cores will help us better characterise the deposit types

  16. Performance Improvement of a Return Channel in a Multistage Centrifugal Compressor Using Multiobjective Optimization.

    Science.gov (United States)

    Nishida, Yoshifumi; Kobayashi, Hiromi; Nishida, Hideo; Sugimura, Kazuyuki

    2013-05-01

    The effect of the design parameters of a return channel on the performance of a multistage centrifugal compressor was numerically investigated, and the shape of the return channel was optimized using a multiobjective optimization method based on a genetic algorithm to improve the performance of the centrifugal compressor. The results of sensitivity analysis using Latin hypercube sampling suggested that the inlet-to-outlet area ratio of the return vane affected the total pressure loss in the return channel, and that the inlet-to-outlet radius ratio of the return vane affected the outlet flow angle from the return vane. Moreover, this analysis suggested that the number of return vanes affected both the loss and the flow angle at the outlet. As a result of optimization, the number of return vane was increased from 14 to 22 and the area ratio was decreased from 0.71 to 0.66. The radius ratio was also decreased from 2.1 to 2.0. Performance tests on a centrifugal compressor with two return channels (the original design and optimized design) were carried out using two-stage test apparatus. The measured flow distribution exhibited a swirl flow in the center region and a reversed swirl flow near the hub and shroud sides. The exit flow of the optimized design was more uniform than that of the original design. For the optimized design, the overall two-stage efficiency and pressure coefficient were increased by 0.7% and 1.5%, respectively. Moreover, the second-stage efficiency and pressure coefficient were respectively increased by 1.0% and 3.2%. It is considered that the increase in the second-stage efficiency was caused by the increased uniformity of the flow, and the rise in the pressure coefficient was caused by a decrease in the residual swirl flow. It was thus concluded from the numerical and experimental results that the optimized return channel improved the performance of the multistage centrifugal compressor.

  17. Research and Development for Multi-stage and Integrated Approach for Seafloor Massive Sulfides (SMSs) Exploration.

    Science.gov (United States)

    Lee, S.; Asakawa, E.; Sumi, T.; Kadoshima, K.; Kose, M.; Murakami, F.; Tsukahara, H.; Koizumi, A.; Koizumi, Y.; Ikeda, M.; Higashi, M.

    2015-12-01

    The seafloor hydrothermal systems and related mineral deposits had been discovered at more than 550 sites so for, and near the one-third of these sites were confirmed as the massive sulfide deposits (Hannington et al., 2011). However, we are now faced with the some task like the preservation of hydrothermal vent community and the secure of amount of mineral reserves for the commercialization. In Japan, the exploration and investigation researches in Japan's EEZ has been conducted from 1980s, and about 20 seafloor hydrothermal fields including several confirmed SMSs has been discovered so far. The Cabinet Office of Government Japan (2013) have been promoting "assessment of the amount of reserves of known mineral deposits, discovery of new mineral deposits and comprehension of the approximate amount of reserves, development of equipment technologies and environmental impact assessment methods related to mining and lifting, including actual offshore tests", expecting projects to be initiated aiming at commercialization with the participation of private companies in or after FY2023-FY2027. As part of the promotion, the "Cross-ministerial Strategic Innovation Promotion Program (SIP)" was started at FY2014 by the Cabinet Office of Government Japan, and the research project of "Next-generation technology for ocean resources exploration" is also ongoing (FY2014-FY2018). J-MARES(Research and Development Partnership for Next Generation Technology of Marine Resources Survey) is one of the private union participated the SIP organized four Inc.(JAPAX, JGI, NSENGI, and MMTEC) aimed at construction of "Multi-stage and integrated approach for SMSs exploration" through the development of upgradable and effectual geophysical exploration methods on seismic and electric-magnetic methods, and combination of the known exploration tools and systems. In this presentation, we introduce some results obtained from two research cruise (JM14-01 and JM14-02) on the known seafloor hydrothermal

  18. Effects of cellular origin on differentiation of human induced pluripotent stem cell-derived endothelial cells.

    Science.gov (United States)

    Hu, Shijun; Zhao, Ming-Tao; Jahanbani, Fereshteh; Shao, Ning-Yi; Lee, Won Hee; Chen, Haodong; Snyder, Michael P; Wu, Joseph C

    2016-06-02

    Human induced pluripotent stem cells (iPSCs) can be derived from various types of somatic cells by transient overexpression of 4 Yamanaka factors (OCT4, SOX2, C-MYC, and KLF4). Patient-specific iPSC derivatives (e.g., neuronal, cardiac, hepatic, muscular, and endothelial cells [ECs]) hold great promise in drug discovery and regenerative medicine. In this study, we aimed to evaluate whether the cellular origin can affect the differentiation, in vivo behavior, and single-cell gene expression signatures of human iPSC-derived ECs. We derived human iPSCs from 3 types of somatic cells of the same individuals: fibroblasts (FB-iPSCs), ECs (EC-iPSCs), and cardiac progenitor cells (CPC-iPSCs). We then differentiated them into ECs by sequential administration of Activin, BMP4, bFGF, and VEGF. EC-iPSCs at early passage (10 < P < 20) showed higher EC differentiation propensity and gene expression of EC-specific markers (PECAM1 and NOS3) than FB-iPSCs and CPC-iPSCs. In vivo transplanted EC-iPSC-ECs were recovered with a higher percentage of CD31(+) population and expressed higher EC-specific gene expression markers (PECAM1, KDR, and ICAM) as revealed by microfluidic single-cell quantitative PCR (qPCR). In vitro EC-iPSC-ECs maintained a higher CD31(+) population than FB-iPSC-ECs and CPC-iPSC-ECs with long-term culturing and passaging. These results indicate that cellular origin may influence lineage differentiation propensity of human iPSCs; hence, the somatic memory carried by early passage iPSCs should be carefully considered before clinical translation.

  19. Effects of cellular origin on differentiation of human induced pluripotent stem cell–derived endothelial cells

    Science.gov (United States)

    Zhao, Ming-Tao; Jahanbani, Fereshteh; Lee, Won Hee; Snyder, Michael P.

    2016-01-01

    Human induced pluripotent stem cells (iPSCs) can be derived from various types of somatic cells by transient overexpression of 4 Yamanaka factors (OCT4, SOX2, C-MYC, and KLF4). Patient-specific iPSC derivatives (e.g., neuronal, cardiac, hepatic, muscular, and endothelial cells [ECs]) hold great promise in drug discovery and regenerative medicine. In this study, we aimed to evaluate whether the cellular origin can affect the differentiation, in vivo behavior, and single-cell gene expression signatures of human iPSC–derived ECs. We derived human iPSCs from 3 types of somatic cells of the same individuals: fibroblasts (FB-iPSCs), ECs (EC-iPSCs), and cardiac progenitor cells (CPC-iPSCs). We then differentiated them into ECs by sequential administration of Activin, BMP4, bFGF, and VEGF. EC-iPSCs at early passage (10 < P < 20) showed higher EC differentiation propensity and gene expression of EC-specific markers (PECAM1 and NOS3) than FB-iPSCs and CPC-iPSCs. In vivo transplanted EC-iPSC–ECs were recovered with a higher percentage of CD31+ population and expressed higher EC-specific gene expression markers (PECAM1, KDR, and ICAM) as revealed by microfluidic single-cell quantitative PCR (qPCR). In vitro EC-iPSC–ECs maintained a higher CD31+ population than FB-iPSC–ECs and CPC-iPSC–ECs with long-term culturing and passaging. These results indicate that cellular origin may influence lineage differentiation propensity of human iPSCs; hence, the somatic memory carried by early passage iPSCs should be carefully considered before clinical translation. PMID:27398408

  20. Tissue-Mimicking Geometrical Constraints Stimulate Tissue-Like Constitution and Activity of Mouse Neonatal and Human-Induced Pluripotent Stem Cell-Derived Cardiac Myocytes

    Directory of Open Access Journals (Sweden)

    Götz Pilarczyk

    2016-01-01

    Full Text Available The present work addresses the question of to what extent a geometrical support acts as a physiological determining template in the setup of artificial cardiac tissue. Surface patterns with alternating concave to convex transitions of cell size dimensions were used to organize and orientate human-induced pluripotent stem cell (hIPSC-derived cardiac myocytes and mouse neonatal cardiac myocytes. The shape of the cells, as well as the organization of the contractile apparatus recapitulates the anisotropic line pattern geometry being derived from tissue geometry motives. The intracellular organization of the contractile apparatus and the cell coupling via gap junctions of cell assemblies growing in a random or organized pattern were examined. Cell spatial and temporal coordinated excitation and contraction has been compared on plain and patterned substrates. While the α-actinin cytoskeletal organization is comparable to terminally-developed native ventricular tissue, connexin-43 expression does not recapitulate gap junction distribution of heart muscle tissue. However, coordinated contractions could be observed. The results of tissue-like cell ensemble organization open new insights into geometry-dependent cell organization, the cultivation of artificial heart tissue from stem cells and the anisotropy-dependent activity of therapeutic compounds.

  1. Double image encryption based on phase-amplitude mixed encoding and multistage phase encoding in gyrator transform domains

    Science.gov (United States)

    Wang, Qu; Guo, Qing; Lei, Liang

    2013-06-01

    We present a novel method for double image encryption that is based on amplitude-phase mixed encoding and multistage random phase encoding in gyrator transform (GT) domains. In the amplitude-phase mixed encoding operation, a random binary distribution matrix is defined to mixed encode two primitive images to a single complex-valued image, which is then encrypted into a stationary white noise distribution by the multistage phase encoding with GTs. Compared with the earlier methods that uses fully phase encoding, the proposed method reduces the difference between two primitive images in key space and sensitivity to the GT orders. The primitive images can be recovered exactly by applying correct keys with initial conditions of chaotic system, the GT orders and the pixel scrambling operation. Numerical simulations demonstrate that the proposed scheme has considerably high security level and certain robustness against data loss and noise disturbance.

  2. Discussion on the Performance of Multistage Centrifugal Pumps%多级离心泵性能的探讨

    Institute of Scientific and Technical Information of China (English)

    赵义; 于文华; 宋杨; 蔡亚光

    2011-01-01

    Considering the hydraulic loss, volumetric loss and mechanical loss of factors influencing multistage centrifugal pumps and different factors is revealed, pumps. pumps are presented and the relatio which provides theory basis and methods centrifugal pumps, through experiments, the nship between the efficiency of centrifugal for the efficient use of multistage centrifugal%综合考虑了离心水泵的水力损失、容积损失和机械损失,通过实验提出了影响多级离心泵性能的因素,揭示了离心泵使用效率与各因素的关系,为高效使用多级离心水泵提供了理论依据和方法。

  3. STATE SPACE MODELING OF DIMENSIONAL MACHINING ERRORS OF SERIAL-PARALLEL HYBRID MULTI-STAGE MACHINING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    XI Lifeng; DU Shichang

    2007-01-01

    The final product quality is determined by cumulation, coupling and propagation of product quality variations from all stations in multi-stage manufacturing systems (MMSs). Modeling and control of variation propagation is essential to improve product quality. However, the current stream of variations (SOV) theory can only solve the problem that a single SOV affects the product quality. Due to the existence of multiple variation streams, limited research has been done on the quality control in serial-parallel hybrid multi-stage manufacturing systems (SPH-MMSs). A state space model and its modeling strategies are developed to describe the multiple variation streams stack-up in an SPH-MMS. The SOV theory is extended to SPH-MMS. The dimensions of system model are reduced to the production-reality level, and the effect and feasibility of the model is validated by a machining case.

  4. Degree of deacetylation chitosan from pen shell (Atrina pectinata) with multistage deacetylation process

    Science.gov (United States)

    Pursetyo, Kustiawan Tri; Purbowati, Pinta; Sulmartiwi, Laksmi

    2017-02-01

    The utilization of pen shell (Atrina pectinata) generally in some areas only as edible portion adductor muscle (meat) so the shells become fishery waste. Shells are raw materials that contain chitin and chitosan. Benefits of chitin and chitosan in various fields of modern industry are quite a lot, including in the pharmaceutical industry, biochemistry, biotechnology, biomedical, food, nutrition, paper, textile, agriculture, cosmetics, and healthcare membrane. Quality of chitosan is influenced by deacetylation degree which is one of the most important chemical characteristics. Deacetylation degree gives affect in application of chitosan, due to the value of amina chain and used to differentiate between chitin and chitosan. Deacetylation degrees of chitosan are determined by several factors such as NaOH concentration, temperature and time process. In addition, treatment of deacetylation process of chitin can give effect to deacetylation degree value of chitosan. The method that was used in this research was an experimental method with a statistical analysis of the data. The results showed that stage deacetylation process of chitin have the effect to increase deacetylation degree of chitosan. Multistage deacetylation process of chitin with 3 stage process was capable to make the deacetylation degree on average 75% with 82.91% of solubility. The increase result of deacetylation degree of chitosan is directly proportional with the increase in solubility

  5. Multi-stage approach for structural damage detection problem using basis pursuit and particle swarm optimization

    Science.gov (United States)

    Gerist, Saleheh; Maheri, Mahmoud R.

    2016-12-01

    In order to solve structural damage detection problem, a multi-stage method using particle swarm optimization is presented. First, a new spars recovery method, named Basis Pursuit (BP), is utilized to preliminarily identify structural damage locations. The BP method solves a system of equations which relates the damage parameters to the structural modal responses using the sensitivity matrix. Then, the results of this stage are subsequently enhanced to the exact damage locations and extents using the PSO search engine. Finally, the search space is reduced by elimination of some low damage variables using micro search (MS) operator embedded in the PSO algorithm. To overcome the noise present in structural responses, a method known as Basis Pursuit De-Noising (BPDN) is also used. The efficiency of the proposed method is investigated by three numerical examples: a cantilever beam, a plane truss and a portal plane frame. The frequency response is used to detect damage in the examples. The simulation results demonstrate the accuracy and efficiency of the proposed method in detecting multiple damage cases and exhibit its robustness regarding noise and its advantages compared to other reported solution algorithms.

  6. Vacuumed gap membrane distillation (vagmed) module, multi-stage vagmed systems, and vagmed processes

    KAUST Repository

    Ghaffour, Noreddine

    2016-06-30

    Vacuumed gap membrane distillation (VAGMED) modules, and multi-stage VAGMED systems and processes using the modules are provided. In an embodiment, the membrane distillation modules (10) can comprise: a) a condenser (12) including a condensation surface (15); b) a first passageway (13) having an inlet for receiving a first feed stream (14) and an outlet through which the first stream can pass out of the first passageway, the first passageway configured to bring the first feed stream into thermal communication with the condensation surface; c) an evaporator (17) including a permeable evaporation surface allowing condensable gas to pass there through; d) a second passageway (18) having an inlet for receiving a second feed stream (19) and an outlet through which the second feed stream can pass out of the second passageway, the second passageway configured to bring the second feed stream into communication with the permeable evaporation surface; and e) an enclosure (24) providing a vacuum compartment within which the condenser, the evaporator and the first and second passageways of the module are contained.

  7. An e-quality control model for multistage machining processes of workpieces

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To track and control the changes of process quality attributes in multistage machining processes(MMPs),an e-quality control(e-QC) model is proposed.The e-QC model is defined as a quality information service node with e-formalizing technology,whose input/output and intermediate process(that is IPO) are known to other nodes,and its implemention in MMPs is provided.In order to establish the e-QC model,a measuring network is constructed to acquire the original quality data,and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC,which can be tracked by information template network in real time.Furthermore,a hierarchical control method is adopted to coordinate e-QCs,in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process quality.At last,a prototype is developed to verify the proposed methods.

  8. Effects of Modified Multistage Field Test on Performance and Physiological Responses in Wheelchair Basketball Players

    Directory of Open Access Journals (Sweden)

    Thierry Weissland

    2015-01-01

    Full Text Available A bioenergetical analysis of manoeuvrability and agility performance for wheelchair players is inexistent. It was aimed at comparing the physiological responses and performance obtained from the octagon multistage field test (MFT and the modified condition in “8 form” (MFT-8. Sixteen trained wheelchair basketball players performed both tests in randomized condition. The levels performed (end-test score, peak values of oxygen uptake (VO2peak, minute ventilation (VEpeak, heart rate (HRpeak, peak and relative blood lactate (Δ[Lact−] = peak – rest values, and the perceived rating exertion (RPE were measured. MFT-8 induced higher VO2peak and VEpeak values compared to MFT (VO2peak: 2.5 ± 0.6 versus 2.3 ± 0.6 L·min−1 and VEpeak: 96.3 ± 29.1 versus 86.6 ± 23.4 L·min−1; P<0.05 with no difference in other parameters. Significant relations between VEpeak and end-test score were correlated for both field tests (P<0.05. At exhaustion, MFT attained incompletely VO2peak and VEpeak. Among experienced wheelchair players, MFT-8 had no effect on test performance but generates higher physiological responses than MFT. It could be explained by demands of wheelchair skills occurring in 8 form during the modified condition.

  9. Multistage dilute acid leaching of a medium grade iron ore to super-concentrate

    Directory of Open Access Journals (Sweden)

    Adeleke A.A.

    2014-01-01

    Full Text Available The phosphorous laden Koton Karfe iron ore is a medium grade iron ore deposit in Nigeria that can be upgraded as a super-concentrate for use at the Aladja Steel Midrex plant. The 75 μm size sample fraction of the ore was preconcentrated with shaking table and leached in the oven at atmospheric pressure with dilute hydrochloric acid in single and multistage leaching sequences of H2O-HCl-H2O and HCl-H2O-H2O. The as-received, as-tabled and asleached samples were then subjected to X-ray fluorescence and microscopic analyses. The results obtained showed that the H2O-HCl-H2O route produced a higher grade concentrate that assayed 68.54% Fe indicating about 58% upgrade in iron content; while the phosphorus and sulphur contents were reduced by about 77 and 99.6% respectively. In addition, the silicon, manganese, and titanium contents were drastically reduced, while potassium was completely eliminated. The upgrade of iron content in the ore to 68.54% and the drastic reduction in phosphorous and sulphur contents has thus rendered the Koton Karfe iron ore suitable for use as a super concentrate for the Aladja steel plant direct reduction iron making process.

  10. Short-Term Multi-Stage Stochastic Optimization of Hydropower Reservoirs Under Meteorological Uncertainty

    Science.gov (United States)

    Schwanenberg, D.; Naumann, S.; Allen, C.

    2014-12-01

    Hydroelectric power systems are characterized by variability and uncertainty in yield and water resources obligations. Market volatility and the growing number of operational constraints for flood control, navigation, environmental obligations and ancillary services (including load balancing requirements for renewable resources) further the need to quantify sources of uncertainty. This research presents an integrated framework to handle several sources of uncertainty. Main focus is on the meteorological forecast uncertainty based on deterministic and probabilistic Numerical Weather Predictions (NWP), its consistent propagation through load and streamflow forecasts, and the generation of scenario trees with novel multi-dimensional distance metrics. The scenario trees enable us to extend a deterministic optimization setup to a multi-stage stochastic optimization approach as the mathematical formulation of the short-term system management. The Federal Columbia River Power System (FCRPS), managed by the Bonneville Power Administration, the US Army Corps of Engineers and the Bureau of Reclamation, serves as a large-scale test case for the application of the new framework. We proof the feasibility of the new approach and verify the operational applicability within a real-time environment.

  11. A multi-stage genome-wide association study of bladder cancer identifies multiple susceptibility loci

    Science.gov (United States)

    Rothman, Nathaniel; Garcia-Closas, Montserrat; Chatterjee, Nilanjan; Malats, Nuria; Wu, Xifeng; Figueroa, Jonine; Real, Francisco X; Van Den Berg, David; Matullo, Giuseppe; Baris, Dalsu; Thun, Michael; Kiemeney, Lambertus A; Vineis, Paolo; De Vivo, Immaculata; Albanes, Demetrius; Purdue, Mark P; Rafnar, Thorunn; Hildebrandt, Michelle A T; Kiltie, Anne E; Cussenot, Olivier; Golka, Klaus; Kumar, Rajiv; Taylor, Jack A; Mayordomo, Jose I; Jacobs, Kevin B; Kogevinas, Manolis; Hutchinson, Amy; Wang, Zhaoming; Fu, Yi-Ping; Prokunina-Olsson, Ludmila; Burdette, Laurie; Yeager, Meredith; Wheeler, William; Tardón, Adonina; Serra, Consol; Carrato, Alfredo; García-Closas, Reina; Lloreta, Josep; Johnson, Alison; Schwenn, Molly; Karagas, Margaret R; Schned, Alan; Andriole, Gerald; Grubb, Robert; Black, Amanda; Jacobs, Eric J; Diver, W Ryan; Gapstur, Susan M; Weinstein, Stephanie J; Virtamo, Jarmo; Cortessis, Victoria K; Gago-Dominguez, Manuela; Pike, Malcolm C; Stern, Mariana C; Yuan, Jian-Min; Hunter, David; McGrath, Monica; Dinney, Colin P; Czerniak, Bogdan; Chen, Meng; Yang, Hushan; Vermeulen, Sita H; Aben, Katja K; Witjes, J Alfred; Makkinje, Remco R; Sulem, Patrick; Besenbacher, Soren; Stefansson, Kari; Riboli, Elio; Brennan, Paul; Panico, Salvatore; Navarro, Carmen; Allen, Naomi E; Bueno-de-Mesquita, H Bas; Trichopoulos, Dimitrios; Caporaso, Neil; Landi, Maria Teresa; Canzian, Federico; Ljungberg, Borje; Tjonneland, Anne; Clavel-Chapelon, Francoise; Bishop, David T; Teo, Mark T W; Knowles, Margaret A; Guarrera, Simonetta; Polidoro, Silvia; Ricceri, Fulvio; Sacerdote, Carlotta; Allione, Alessandra; Cancel-Tassin, Geraldine; Selinski, Silvia; Hengstler, Jan G; Dietrich, Holger; Fletcher, Tony; Rudnai, Peter; Gurzau, Eugen; Koppova, Kvetoslava; Bolick, Sophia C E; Godfrey, Ashley; Xu, Zongli; Sanz-Velez, José I; García-Prats, María D; Sanchez, Manuel; Valdivia, Gabriel; Porru, Stefano; Benhamou, Simone; Hoover, Robert N; Fraumeni, Joseph F; Silverman, Debra T; Chanock, Stephen J

    2010-01-01

    We conducted a multi-stage, genome-wide association study (GWAS) of bladder cancer with a primary scan of 589,299 single nucleotide polymorphisms (SNPs) in 3,532 cases and 5,120 controls of European descent (5 studies) followed by a replication strategy, which included 8,381 cases and 48,275 controls (16 studies). In a combined analysis, we identified three new regions associated with bladder cancer on chromosomes 22q13.1, 19q12 and 2q37.1; rs1014971, (P=8×10−12) maps to a non-genic region of chromosome 22q13.1; rs8102137 (P=2×10−11) on 19q12 maps to CCNE1; and rs11892031 (P=1×10−7) maps to the UGT1A cluster on 2q37.1. We confirmed four previous GWAS associations on chromosomes 3q28, 4p16.3, 8q24.21 and 8q24.3, validated previous candidate associations for the GSTM1 deletion (P=4×10−11) and a tag SNP for NAT2 acetylation status (P=4×10−11), as well as demonstrated smoking interactions with both regions. Our findings on common variants associated with bladder cancer risk should provide new insights into mechanisms of carcinogenesis. PMID:20972438

  12. Consolidation Theory for a Stone Column Composite Foundation under Multistage Loading

    Directory of Open Access Journals (Sweden)

    Shenggen Huang

    2016-01-01

    Full Text Available The consolidation theories considering instant load cannot fully reveal the consolidation mechanism of a stone column composite foundation used in the expressway embankments due to the time effect of loading; that is, the expressway embankments are often constructed in several stages for a long time. Meanwhile, owing to the special property that the pile-soil stress ratio is larger than 1, the consolidation theory for sand drain well foundation cannot be used directly in the consolidation analysis of stone column composite foundation. Based on the principle that the vertical load applied on the composite foundation is shared by the stone column and the surrounding soil, the governing solutions for the stone column composite foundation under a multistage load are established. By virtue of the separation of variables, the corresponding solutions of degree of consolidation for loading stage and maintaining load stage are derived separately. According to the Carrillo theorem, the solution for the average total degree of consolidation of entire composite foundation is also obtained. Finally, the reasonableness of the present solution has been verified by comparing the consolidation curve calculated by the present solution with that measured by site test.

  13. A Multi-Stage Reverse Logistics Network Problem by Using Hybrid Priority-Based Genetic Algorithm

    Science.gov (United States)

    Lee, Jeong-Eun; Gen, Mitsuo; Rhee, Kyong-Gu

    Today remanufacturing problem is one of the most important problems regarding to the environmental aspects of the recovery of used products and materials. Therefore, the reverse logistics is gaining become power and great potential for winning consumers in a more competitive context in the future. This paper considers the multi-stage reverse Logistics Network Problem (m-rLNP) while minimizing the total cost, which involves reverse logistics shipping cost and fixed cost of opening the disassembly centers and processing centers. In this study, we first formulate the m-rLNP model as a three-stage logistics network model. Following for solving this problem, we propose a Genetic Algorithm pri (GA) with priority-based encoding method consisting of two stages, and introduce a new crossover operator called Weight Mapping Crossover (WMX). Additionally also a heuristic approach is applied in the 3rd stage to ship of materials from processing center to manufacturer. Finally numerical experiments with various scales of the m-rLNP models demonstrate the effectiveness and efficiency of our approach by comparing with the recent researches.

  14. A Multistage Feature Selection Model for Document Classification Using Information Gain and Rough Set

    Directory of Open Access Journals (Sweden)

    Mrs. Leena. H. Patil

    2014-11-01

    Full Text Available Huge number of documents are increasing rapidly, therefore, to organize it in digitized form text categorization becomes an challenging issue. A major issue for text categorization is its large number of features. Most of the features are noisy, irrelevant and redundant, which may mislead the classifier. Hence, it is most important to reduce dimensionality of data to get smaller subset and provide the most gain in information. Feature selection techniques reduce the dimensionality of feature space. It also improves the overall accuracy and performance. Hence, to overcome the issues of text categorization feature selection is considered as an efficient technique . Therefore, we, proposed a multistage feature selection model to improve the overall accuracy and performance of classification. In the first stage document preprocessing part is performed. Secondly, each term within the documents are ranked according to their importance for classification using the information gain. Thirdly rough set technique is applied to the terms which are ranked importantly and feature reduction is carried out. Finally a document classification is performed on the core features using Naive Bayes and KNN classifier. Experiments are carried out on three UCI datasets, Reuters 21578, Classic 04 and Newsgroup 20. Results show the better accuracy and performance of the proposed model.

  15. Optimal phasing of district heating network investments using multi-stage stochastic programming

    Directory of Open Access Journals (Sweden)

    Romain Stephane Claude Lambert

    2016-06-01

    Full Text Available Most design optimisation studies for district heating systems have focused on the optimal sizing of network assets and on the location of production units. However, the strategic value of the flexibility in phasing of the inherently modular heat networks, which is an important aspect in many feasibility studies for district heating schemes in the UK, is almost always neglected in the scientific literature. This paper considers the sequential problem faced by a decision-maker in the phasing of long-term investments into district heating networks and their expansions. The problem is formulated as a multi-stage stochastic programme to determine the annual capital expenditure that maximises the expected net present value of the project. The optimisation approach is illustrated by applying it to the hypothetical case of the UK’s Marston Vale eco town. It was found that the approach is capable of simulating the optimal growth of a network, from both a single heat source or separate islands of growth, as well as the optimal marginal expansion of an existing district heating network. The proposed approach can be used by decision makers as a framework to determine both the optimal phasing and extension of district heating networks and can be adapted simply to various, more complex real-life situations by introducing additional constraints and parameters. The versatility of the base formulation also makes it a powerful approach regardless of the size of the network and also potentially applicable to cooling networks.

  16. A Multistage Control Mechanism for Group-Based Machine-Type Communications in an LTE System

    Directory of Open Access Journals (Sweden)

    Wen-Chien Hung

    2013-01-01

    Full Text Available When machine-type communication (MTC devices perform the long-term evolution (LTE attach procedure without bit rate limitations, they may produce congestion in the core network. To prevent this congestion, the LTE standard suggests using group-based policing to regulate the maximum bit rate of all traffic generated by a group of MTC devices. However, previous studies on the access point name-aggregate maximum bit rate based on group-based policing are relatively limited. This study proposes a multistage control (MSC mechanism to process the operations of maximum bit rate allocation based on resource-use information. For performance evaluation, this study uses a Markov chain with to analyze MTC application in a 3GPP network. Traffic flow simulations in an LTE system indicate that the MSC mechanism is an effective bandwidth allocation method in an LTE system with MTC devices. Experimental results show that the MSC mechanism achieves a throughput 22.5% higher than that of the LTE standard model using the group-based policing, and it achieves a lower delay time and greater long-term fairness as well.

  17. Filtered chorochronic interface as a capability for 3-D unsteady throughflow analysis of multistage turbomachinery

    Science.gov (United States)

    Gerolymos, G. A.

    2013-02-01

    This note reviews the widely used phased-lagged [Erdos, J. L., E. Alzner, and W. McNally. 1977. AIAA Journal 15: 1559-68.] approach and corresponding chorochronic interface relations [Gerolymos G. A., G. J. Michon, and J. Neubauer. 2002. Journal of Propulsion and Power 18: 1139-52.] and explores its potential extension to the approximate unsteady throughflow analysis of multistage turbomachinery. The basic relations pertaining to the binary blade-row interaction case, for which chorochronic periodicity is exact in a phase-averaged rans framework, are briefly formulated, and selected computational examples illustrate the application of the method. Then, the filtered chorochronic interface is defined as the unsteady counterpart of the well-known mixing-plane concept. This interface takes into account only those tθ-waves which are compatible with the interaction of the immediately upstream and downstream blade-rows. The concept, which is similar to the decomposition-and-superposition method [Li, H. D., and L. He. 2005. ASME J ournal of Turbomachinery 127: 589-98.], is illustrated by 3-D computations of a ½-stage transonic compressor.

  18. Hydraulic design to optimize the treatment capacity of Multi-Stage Filtration units

    Science.gov (United States)

    Mushila, C. N.; Ochieng, G. M.; Otieno, F. A. O.; Shitote, S. M.; Sitters, C. W.

    2016-04-01

    Multi-Stage Filtration (MSF) can provide a robust treatment alternative for surface water sources of variable water quality in rural communities at low operation and maintenance costs. MSF is a combination of Slow Sand Filters (SSFs) and Pre-treatment systems. The general objective of this research was to optimize the treatment capacity of MSF. A pilot plant study was undertaken to meet this objective. The pilot plant was monitored for a continuous 98 days from commissioning till the end of the project. Three main stages of MSF namely: The Dynamic Gravel Filter (DGF), Horizontal-flow Roughing Filter (HRF) and SSF were identified, designed and built. The response of the respective MSF units in removal of selected parameters guiding drinking water quality such as microbiological (Faecal and Total coliform), Suspended Solids, Turbidity, PH, Temperature, Iron and Manganese was investigated. The benchmark was the Kenya Bureau (KEBS) and World Health Organization (WHO) Standards for drinking water quality. With respect to microbiological raw water quality improvement, MSF units achieved on average 98% Faecal and 96% Total coliform removal. Results obtained indicate that implementation of MSF in rural communities has the potential to increase access to portable water to the rural populace with a probable consequent decrease in waterborne diseases. With a reduced down time due to illness, more time would be spent in undertaking other economic activities.

  19. Mode excitation in a generator of diffraction radiation with a multistage interaction space

    Science.gov (United States)

    Miroshnichenko, V. S.; Senkevich, E. B.; Pivovarova, A. G.; Yudintsev, D. V.

    2010-08-01

    We present the results of studying theoretically and experimentally the peculiarities of mode excitation in a generator of diffraction radiation with the two- and three-cascade interaction space in one open resonator. To describe the multistage interaction mechanism, the theoretical model used considers the excitation of the TEM0nq modes, which have n in-phase field “spots,” i.e., cascades, along the direction of the electron beam motion. It is shown that even the use of the two-cascade interaction space with the TEM01q modes allows one to reduce the starting current of the generator by 1.91 times. The results of studying experimentally the two-cascade generator in the 5 and 1.5-mm wavelength ranges are presented. The in-phase property of the electron beam with the resonance field was achieved by disrupting the periodicity of the lattice slots at the center of the interaction space. The output power of the two-stage generator of 5-mm diffraction radiation in the TEM013 mode ranged from 3 to 5 W. We also observed a 4-5-fold increase in the starting current for the regime of surface waves.

  20. Variation transmission model for setting acceptance criteria in a multi-staged pharmaceutical manufacturing process.

    Science.gov (United States)

    Montes, Richard O

    2012-03-01

    Pharmaceutical manufacturing processes consist of a series of stages (e.g., reaction, workup, isolation) to generate the active pharmaceutical ingredient (API). Outputs at intermediate stages (in-process control) and API need to be controlled within acceptance criteria to assure final drug product quality. In this paper, two methods based on tolerance interval to derive such acceptance criteria will be evaluated. The first method is serial worst case (SWC), an industry risk minimization strategy, wherein input materials and process parameters of a stage are fixed at their worst-case settings to calculate the maximum level expected from the stage. This maximum output then becomes input to the next stage wherein process parameters are again fixed at worst-case setting. The procedure is serially repeated throughout the process until the final stage. The calculated limits using SWC can be artificially high and may not reflect the actual process performance. The second method is the variation transmission (VT) using autoregressive model, wherein variation transmitted up to a stage is estimated by accounting for the recursive structure of the errors at each stage. Computer simulations at varying extent of variation transmission and process stage variability are performed. For the scenarios tested, VT method is demonstrated to better maintain the simulated confidence level and more precisely estimate the true proportion parameter than SWC. Real data examples are also presented that corroborate the findings from the simulation. Overall, VT is recommended for setting acceptance criteria in a multi-staged pharmaceutical manufacturing process.

  1. 3D Multistage Simulation of Each Component of the GE90 Turbofan Engine

    Science.gov (United States)

    Turner, Mark; Topp, Dave; Veres, Joe

    1999-01-01

    A 3D multistage simulation of each component of the GE90 Turbofan engine has been made. This includes 49 blade rows. A coupled simulation of all blade rows will be made very soon. The simulation is running using two levels of parallelism. The first level is on a blade row basis with information shared using files. The second level is using a grid domain decomposition with information shared using MPI. Timings will be shown for running on the SP2, an SGI Origin and a distributed system of HP workstations. On the HP workstations, the CHIMP version of MPI is used, with queuing supplied by LSF (Load Sharing Facility). A script-based control system is used to ensure reliability. An MPEG movie illustrating the flow simulation of the engine has been created using PV3, a parallel visualization library created by Bob Haimes of MIT. PVM is used to create a virtual machine from 10 HP workstations and display on an SGI workstation. A representative component simulation will be compared to rig data to demonstrate its usefulness in turbomachinery design and analysis.

  2. Multi-stage robust scheme for citrus identification from high resolution airborne images

    Science.gov (United States)

    Amorós-López, Julia; Izquierdo Verdiguier, Emma; Gómez-Chova, Luis; Muñoz-Marí, Jordi; Zoilo Rodríguez-Barreiro, Jorge; Camps-Valls, Gustavo; Calpe-Maravilla, Javier

    2008-10-01

    Identification of land cover types is one of the most critical activities in remote sensing. Nowadays, managing land resources by using remote sensing techniques is becoming a common procedure to speed up the process while reducing costs. However, data analysis procedures should satisfy the accuracy figures demanded by institutions and governments for further administrative actions. This paper presents a methodological scheme to update the citrus Geographical Information Systems (GIS) of the Comunidad Valenciana autonomous region, Spain). The proposed approach introduces a multi-stage automatic scheme to reduce visual photointerpretation and ground validation tasks. First, an object-oriented feature extraction process is carried out for each cadastral parcel from very high spatial resolution (VHR) images (0.5m) acquired in the visible and near infrared. Next, several automatic classifiers (decision trees, multilayer perceptron, and support vector machines) are trained and combined to improve the final accuracy of the results. The proposed strategy fulfills the high accuracy demanded by policy makers by means of combining automatic classification methods with visual photointerpretation available resources. A level of confidence based on the agreement between classifiers allows us an effective management by fixing the quantity of parcels to be reviewed. The proposed methodology can be applied to similar problems and applications.

  3. Multi-stage axial flow compressors characteristics estimation based on system identification

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Wentong; Liu, Yongwen; Su, Ming [Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China); Yu, Nanhua [Guangdong Electric Power Research Institute, 73 Meihua Road, Guangzhou 510600 (China)

    2008-02-15

    The most troublesome part in the development of a component-based engine models is the compressor module because of the strong dependence of its performance on rotational speed. For this purpose, a performance characteristics estimation method of multi-stage axial flow compressors are proposed in this paper. The newly proposed estimation technique of average infinitesimal stage characteristics satisfies the analogy criterion perfectly due to the use of a new conception of infinitesimal stage and the improved analogy theory. The overall compressor performance characteristics are estimated through a stage by stage calculation based on the improved analogy theory and the average stage characteristics. To minimize the error between the calculated characteristic and the tested characteristic of the compressor at high rotational speeds, the average stages performance characteristics are identified using an optimization method. The technique improves the traditional scaling method by taking into account the effects of air density change and rotational speeds, and it makes use of available data efficiently. In addition, it reflects the own performance characteristics of the original compressor. (author)

  4. Multi-stage axial flow compressors characteristics estimation based on system identification

    Energy Technology Data Exchange (ETDEWEB)

    Ma Wentong [Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China)], E-mail: wentongma@sjtu.org; Liu Yongwen; Su Ming [Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China); Yu Nanhua [Guangdong Electric Power Research Institute, 73 Meihua Road, Guangzhou 510600 (China)

    2008-02-15

    The most troublesome part in the development of a component-based engine models is the compressor module because of the strong dependence of its performance on rotational speed. For this purpose, a performance characteristics estimation method of multi-stage axial flow compressors are proposed in this paper. The newly proposed estimation technique of average infinitesimal stage characteristics satisfies the analogy criterion perfectly due to the use of a new conception of infinitesimal stage and the improved analogy theory. The overall compressor performance characteristics are estimated through a stage by stage calculation based on the improved analogy theory and the average stage characteristics. To minimize the error between the calculated characteristic and the tested characteristic of the compressor at high rotational speeds, the average stages performance characteristics are identified using an optimization method. The technique improves the traditional scaling method by taking into account the effects of air density change and rotational speeds, and it makes use of available data efficiently. In addition, it reflects the own performance characteristics of the original compressor.

  5. Development of novel general equation for multistage epicyclic gearset with corrected teeth: fixed-speed approach

    Science.gov (United States)

    Kijanka, Piotr; Jablonski, Adam; Dworakowski, Ziemowit; Dziedziech, Kajetan; Uhl, Tadeusz

    2016-04-01

    The paper illustrates a general equation in a new form, which allows calculating the characteristic frequencies of any kind of epicyclic gear sets with a ring, a sun, and planets. Moreover, presented equation takes into account corrected teeth (i.e. where the equality 2P+S=R is not fulfilled). This happens when gearboxes contain gears where corrected teeth procedure was adopted during designing stage. Presented solution can refine the configuration modules of the Condition Monitoring Systems (CMS) in such a way that allows to configure systems into larger groups than now available, i.e. multistage gear sets systems with epicyclic gears. Such CMS are capable of early mechanical faults detection, which prevents from costly critical repairs. For instance, fault detection of wind turbines is typically based on vibration and process signals analysis. Illustrated possible enhancement of configuration module is the basis for determining the energy bands in the spectra and envelope spectra in the process of identifying characteristic frequencies caused by gear defects.

  6. Vibration-based angular speed estimation for multi-stage wind turbine gearboxes

    Science.gov (United States)

    Peeters, Cédric; Leclère, Quentin; Antoni, Jérôme; Guillaume, Patrick; Helsen, Jan

    2017-05-01

    Most processing tools based on frequency analysis of vibration signals are only applicable for stationary speed regimes. Speed variation causes the spectral content to smear, which encumbers most conventional fault detection techniques. To solve the problem of non-stationary speed conditions, the instantaneous angular speed (IAS) is estimated. Wind turbine gearboxes however are typically multi-stage gearboxes, consisting of multiple shafts, rotating at different speeds. Fitting a sensor (e.g. a tachometer) to every single stage is not always feasible. As such there is a need to estimate the IAS of every single shaft based on the vibration signals measured by the accelerometers. This paper investigates the performance of the multi-order probabilistic approach for IAS estimation on experimental case studies of wind turbines. This method takes into account the meshing orders of the gears present in the system and has the advantage that a priori it is not necessary to associate harmonics with a certain periodic mechanical event, which increases the robustness of the method. It is found that the MOPA has the potential to easily outperform standard band-pass filtering techniques for speed estimation. More knowledge of the gearbox kinematics is beneficial for the MOPA performance, but even with very little knowledge about the meshing orders, the MOPA still performs sufficiently well to compete with the standard speed estimation techniques. This observation is proven on two different data sets, both originating from vibration measurements on the gearbox housing of a wind turbine.

  7. Spatial dynamics of large-scale, multistage crab (Callinectes sapidus) dispersal: Determinants and consequences for recruitment

    Science.gov (United States)

    Etherington, L.L.; Eggleston, D.B.

    2003-01-01

    We assessed determinants and consequences of multistage dispersal on spatial recruitment of the blue crab, Callinectes sapidus, within the Croatan, Albemarle, Pamlico Estuarine System (CAPES), North Carolina, U.S.A. Large-scale sampling of early juvenile crabs over 4 years indicated that spatial abundance patterns were size-dependent and resulted from primary post-larval dispersal (pre-settlement) and secondary juvenile dispersal (early post-settlement). In general, primary dispersal led to high abundances within more seaward habitats, whereas secondary dispersal (which was relatively consistent) expanded the distribution of juveniles, potentially increasing the estuarine nursery capacity. There were strong relationships between juvenile crab density and specific wind characteristics; however, these patterns were spatially explicit. Various physical processes (e.g., seasonal wind events, timing and magnitude of tropical cyclones) interacted to influence dispersal during multiple stages and determined crab recruitment patterns. Our results suggest that the nursery value of different habitats is highly dependent on the dispersal potential (primary and secondary dispersal) to and from these areas, which is largely determined by the relative position of habitats within the estuarine landscape.

  8. A new strategy of instantaneous angular speed extraction and its application to multistage gearbox fault diagnosis

    Science.gov (United States)

    Li, Bing; Zhang, Xining

    2017-05-01

    Owing to its unique benefits, Instantaneous Angular Speed (IAS) has become the focus of a great deal of research for monitoring mechanical parts of rotating machines in the past few years. However, the efficacy of IAS-based signal processing techniques essentially depends on the estimation method of IAS and the complexity of the mechanical system. When it is applied to complex systems like turbines, gearboxes, conventional IAS itself still has some flaws and insufficiencies such as longer data stream, quantization noise and structural noise. In order to address these issues, this paper proposes an alternative IAS estimation approach named Instantaneous Angular Phase Demodulation (IAPD) IAS together with an improved procedure involving signal reconstruction, empirical mode decomposition (EMD) and envelope analysis. Thereafter, two kinds of multistage gearboxes under different working conditions are developed to experimentally demonstrate the accuracy and effectiveness of the new IAS measurement. Analysis results suggest that the quantization noise can be significantly reduced or even avoided in the IAPD-IAS signal compared with the conventional IAS signal. Moreover, by means of the new procedure, the computational efficiency can be greatly improved and fault characteristics are dramatically enhanced in the envelope spectrum where deterministic frequency component and its harmonics corresponding to fault characteristics are displayed clearly.

  9. Rigging Test Bed Development for Validation of Multi-Stage Decelerator Extractions

    Science.gov (United States)

    Kenig, Sivan J.; Gallon, John C.; Adams, Douglas S.; Rivellini, Tommaso P.

    2013-01-01

    The Low Density Supersonic Decelerator project is developing new decelerator systems for Mars entry which would include testing with a Supersonic Flight Dynamics Test Vehicle. One of the decelerator systems being developed is a large supersonic ringsail parachute. Due to the configuration of the vehicle it is not possible to deploy the parachute with a mortar which would be the preferred method for a spacecraft in a supersonic flow. Alternatively, a multi-stage extraction process using a ballute as a pilot is being developed for the test vehicle. The Rigging Test Bed is a test venue being constructed to perform verification and validation of this extraction process. The test bed consists of a long pneumatic piston device capable of providing a constant force simulating the ballute drag force during the extraction events. The extraction tests will take place both inside a high-bay for frequent tests of individual extraction stages and outdoors using a mobile hydraulic crane for complete deployment tests from initial pack pull out to canopy extraction. These tests will measure line tensions and use photogrammetry to track motion of the elements involved. The resulting data will be used to verify packing and rigging as well, as validate models and identify potential failure modes in order to finalize the design of the extraction system.

  10. Numerical framework to model temporally resolved multi-stage dynamic systems.

    Science.gov (United States)

    Zakharov, M N; Bhasin, S; Szafran, A T; Mancini, M A; Jasuja, R

    2012-11-01

    Numerical modeling of steroid hormone signaling presents an exciting challenge involving spatiotemporal coordination of multiple events. Ligand binding in cytoplasm triggers dissociation and/or association of coregulators which subsequently regulate DNA binding and transcriptional activity in nucleus. In order to develop a comprehensive multi-stage model, it is imperative to follow not only the transcriptional outcomes but also the intermediate protein complexes. Accordingly, we developed a software toolkit for simulating complex biochemical pathways as a set of non-linear differential equations in LabVIEW (Laboratory Virtual Instrumentation and Engineering Workbench, National Instruments, Austin, TX) environment. The toolkit is visual, highly modular, loosely coupled with the rest of LabVIEW, scalable and extensible. The toolkit can be used to develop and validate biochemical models and estimate model parameters from existing experimental data. We illustrate the application of the toolkit for simulation of steroid hormone response in cells, and demonstrate how the toolkit can be employed for other biological and chemical systems as well. The software module presented here can be used stand-alone as well as built into data collection and analysis applications.

  11. Conceptual designs of E × B multistage depressed collectors for gyrotrons

    Science.gov (United States)

    Wu, Chuanren; Pagonakis, Ioannis Gr.; Gantenbein, Gerd; Illy, Stefan; Thumm, Manfred; Jelonnek, John

    2017-04-01

    Multistage depressed collectors are challenges for high-power, high-frequency fusion gyrotrons. Two concepts exist in the literature: (1) unwinding the spent electron beam cyclotron motion utilizing non-adiabatic transitions of magnetic fields and (2) sorting and collecting the electrons using the E × B drift. To facilitate the collection by the drift, the hollow electron beam can be transformed to one or more thin beams before applying the sorting. There are many approaches, which can transform the hollow electron beam to thin beams; among them, two approaches similar to the tilted electric field collectors of traveling wave tubes are conceptually studied in this paper: the first one transforms the hollow circular electron beam to an elongated elliptic beam, and then the thin elliptic beam is collected by the E × B drift; the second one splits an elliptic or a circular electron beam into two arc-shaped sheet beams; these two parts are collected individually. The functionality of these concepts is proven by CST simulations. A model of a three-stage collector for a 170 GHz, 1 MW gyrotron using the latter approach shows 76% collector efficiency while taking secondary electrons and realistic electron beam characteristics into account.

  12. Optimal placement of water-lubricated rubber bearings for vibration reduction of flexible multistage rotor systems

    Science.gov (United States)

    Liu, Shibing; Yang, Bingen

    2017-10-01

    Flexible multistage rotor systems with water-lubricated rubber bearings (WLRBs) have a variety of engineering applications. Filling a technical gap in the literature, this effort proposes a method of optimal bearing placement that minimizes the vibration amplitude of a WLRB-supported flexible rotor system with a minimum number of bearings. In the development, a new model of WLRBs and a distributed transfer function formulation are used to define a mixed continuous-and-discrete optimization problem. To deal with the case of uncertain number of WLRBs in rotor design, a virtual bearing method is devised. Solution of the optimization problem by a real-coded genetic algorithm yields the locations and lengths of water-lubricated rubber bearings, by which the prescribed operational requirements for the rotor system are satisfied. The proposed method is applicable either to preliminary design of a new rotor system with the number of bearings unforeknown or to redesign of an existing rotor system with a given number of bearings. Numerical examples show that the proposed optimal bearing placement is efficient, accurate and versatile in different design cases.

  13. INFLUENCE OF NANOFILTRATION PRETREATMENT ON SCALE DEPOSITION IN MULTI-STAGE FLASH THERMAL DESALINATION PLANTS

    Directory of Open Access Journals (Sweden)

    Aiman E Al-Rawajfeh

    2011-01-01

    Full Text Available Scale formation represents a major operational problem encountered in thermal desalination plants. In current installed plants, and to allow for a reasonable safety margin, sulfate scale deposition limits the top brine temperature (TBT in multi-stage flash (MSF distillers up to 110-112oC. This has significant effect on the unit capital, operational and water production cost. In this work, the influence of nanofiltration (NF pretreatment on the scale deposition potential and increasing TBT in MSF thermal desalination plants is modeled on the basis of mass transfer with chemical reaction of solutes in the brine. Full and partial NF-pretreatment of the feed water were investigated. TBT can be increased in MSF by increasing the percentage of NF-treated feed. Full NF pretreatment of the make-up allows TBT in the MSF plant to be raised up to 175oC in the case of di hybrid NF-MSF and up to 165oC in the case of tri hybrid NF-RO-MSF. The significant scale reduction is associated with increasing flashing range, unit recovery, unit performance, and will lead to reduction in heat transfer surface area, pumping power and therefore, water production cost.

  14. Performance Analysis of Dual-Priority Multilayer Multistage Interconnection Networks under Multicast Environment

    Directory of Open Access Journals (Sweden)

    Dimitris C. Vasiliadis

    2011-06-01

    Full Text Available Next-generation network architectures strive to achieve high bandwidth and ultralow latency for the packets traversing the offered end-to-end paths. Multistage Interconnection Networks (MINs are often employed for implementing NGNs, but while MINs are fairly flexible in handling varieties of traffic loads, they tend to quickly saturate under broadcast and multicast traffic, especially at increasing size networks. As a response to this issue, multilayer MINs have been proposed, however their performance prediction and evaluation has not been studied sufficiently insofar. In this paper, we evaluate and discuss the performance of multilayer MINs under multicast traffic, considering also two levels of packet priorities, since support for multiple QoS levels is an indispensible requirement for NGNs. Different offered loads and buffer size configurations are examined in this context, and performance results are given for the two most important network performance factors, namely packet throughput and delay. We also introduce and calculate a universal performance fac­tor, which includes the importance aspect of each of the above main performance factors. The findings of this study can be used by NGN system designers in order to predict the performance of each configuration and adjust the design of their communication infrastructure to the traffic requirements at hand.

  15. Non-Cancellation Multistage Kurtosis Maximization with Prewhitening for Blind Source Separation

    Directory of Open Access Journals (Sweden)

    Xiang Chen

    2009-01-01

    Full Text Available Chi et al. recently proposed two effective non-cancellation multistage (NCMS blind source separation algorithms, one using the turbo source extraction algorithm (TSEA, called the NCMS-TSEA, and the other using the fast kurtosis maximization algorithm (FKMA, called the NCMS-FKMA. Their computational complexity and performance heavily depend on the dimension of multisensor data, that is, number of sensors. This paper proposes the inclusion of the prewhitening processing in the NCMS-TSEA and NCMS-FKMA prior to source extraction. We come up with four improved algorithms, referred to as the PNCMS-TSEA, the PNCMS-FKMA, the PNCMS-TSEA(p, and the PNCMS-FKMA(p. Compared with the existing NCMS-TSEA and NCMS-FKMA, the former two algorithms perform with significant computational complexity reduction and some performance improvements. The latter two algorithms are generalized counterparts of the former two algorithms with the single source extraction module replaced by a bank of source extraction modules in parallel at each stage. In spite of the same performance of PNCMS-TSEA and PNCMS-TSEA(p (PNCMS-FKMA and PNCMS-FKMA(p, the merit of this parallel source extraction structure lies in much shorter processing latency making the PNCMS-TSEA(p and PNCMS-FKMA(p well suitable for software and hardware implementations. Some simulation results are presented to verify the efficacy and computational efficiency of the proposed algorithms.

  16. Transport line for a multi-staged laser-plasma acceleration: DACTOMUS

    Science.gov (United States)

    Chancé, Antoine; Delferrière, Olivier; Schwindling, Jérôme; Bruni, Christelle; Delerue, Nicolas; Specka, Arnd; Cros, Brgitte; Maynard, Gillies; Paradkar, Bhooshan S.; Mora, Patrick

    2014-03-01

    Laser-plasma acceleration is one of the most promising techniques to reach very high acceleration gradients up to a few hundreds of GeV/m. In order to push this acceleration scheme in the domain of the very high energies, the CILEX project was launched with the laser APOLLON. One of the main topics of this project is to study multi-staged acceleration. It consists in generating and pre-accelerating electrons in a first laser-plasma stage, to transport them up to a second stage where the electrons are accelerated again thanks to another laser pulse. The DACTOMUS project, based on a collaboration CEA-IRFU, CEA-IRAMIS, LAL, LPGP, LULI and LLR, aims at the study and realization of such a transfer line between these two stages. Firstly, a prototype will be developed and tested by the groups of CEA-IRAMIS-SPAM, LPGP, and LULI on the UHI100 facility (CEA-SPAM). This collaboration must enable to realize the first acceleration stage. For the transport line prototype, the main difficulties are to realize a very compact and energy accepting line with diagnostics to characterize the electron beam. We will present here the optics of this line, its performances and the inserted diagnostics.

  17. Transport line for a multi-staged laser-plasma acceleration: DACTOMUS

    Energy Technology Data Exchange (ETDEWEB)

    Chancé, Antoine, E-mail: antoine.chance@cea.fr [CEA, IRFU, SACM, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Delferrière, Olivier; Schwindling, Jérôme [CEA, IRFU, SACM, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Bruni, Christelle; Delerue, Nicolas [LAL, UMR9607, CNRS and Université Paris Sud, Orsay (France); Specka, Arnd [LLR, UMR7638, CNRS and Ecole Polytechnique, Palaiseau (France); Cros, Brgitte; Maynard, Gillies; Paradkar, Bhooshan S. [LPGP, UMR8578, CNRS and Université Paris Sud, Orsay (France); Mora, Patrick [CPhT, UMR7644, CNRS and Ecole Polytechnique, Palaiseau (France)

    2014-03-11

    Laser-plasma acceleration is one of the most promising techniques to reach very high acceleration gradients up to a few hundreds of GeV/m. In order to push this acceleration scheme in the domain of the very high energies, the CILEX project was launched with the laser APOLLON. One of the main topics of this project is to study multi-staged acceleration. It consists in generating and pre-accelerating electrons in a first laser-plasma stage, to transport them up to a second stage where the electrons are accelerated again thanks to another laser pulse. The DACTOMUS project, based on a collaboration CEA-IRFU, CEA-IRAMIS, LAL, LPGP, LULI and LLR, aims at the study and realization of such a transfer line between these two stages. Firstly, a prototype will be developed and tested by the groups of CEA-IRAMIS-SPAM, LPGP, and LULI on the UHI100 facility (CEA-SPAM). This collaboration must enable to realize the first acceleration stage. For the transport line prototype, the main difficulties are to realize a very compact and energy accepting line with diagnostics to characterize the electron beam. We will present here the optics of this line, its performances and the inserted diagnostics.

  18. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    Directory of Open Access Journals (Sweden)

    L. D. Sánchez

    2012-06-01

    Full Text Available This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF in a multi-stage filtration (MSF plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%. Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

  19. Multi-stage geothermal power generation system; Tadan chinetsu hatsuden hoho

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K.; Odanaka, K.; Shakunaga, N.

    1996-03-08

    In the conventional geothermal power generation system, the high pressure steam and low pressure steam produced in each steam generation plant are separately sent to the power generation site through the pipeline for operating the high pressure turbine or low pressure turbine. The cost for installing the pipeline facility is a problem in this system. This invention relates to the geothermal power generation system which are equipped with multi-stage turbines and power generators. According to the invention, the high pressure top turbine and generator are installed at the pit mouth of each well to generate the power. The wet steam exhausted from the top turbine is mixed together with hot water separated from the high pressure separator or the flash steam. The mixture is fed to the low pressure separator to carry out the gas/liquid separation. The steam recovered from the gas/liquid separator is fed to the low pressure base turbine for power generation. This way facilitates the alteration of equipment when the gushing character of the geothermal well changes as the time passes by. 2 figs., 1 tab.

  20. Oncogenic role of clusterin overexpression in multistage colorectal tumorigenesis and progression

    Institute of Scientific and Technical Information of China (English)

    Dan Xie; Liang Hu; Xin-Yuan Guan; Jonathan S.T. Sham; Wei-Fen Zeng; Li-Hong Che; Meng Zhang; Hui-Xi Wu; Han-Liang Lin; Jian-Ming Wen; Sze Hang Lau

    2005-01-01

    AIM: To investigate the expression pattern of clusterin in colorectal adenoma-carcinoma-metastasis series, and to explore the potential role of dusterin in multistage colorectal tumorigenesis and progression.METHOD:S: A colorectal carcinoma (CRC)-tissue microarray (TMA), which contained 85 advanced CRCs including 43 cases of Dukes B, 21 of Dukes C and 21 of Dukes D tumors, were used for assessing the expression of clusterin (clone 41D) and tumor cell apoptotic index (AI) by immunohistochemistry and TUNEL assay, respectively. Moreover the potential correlation of dusterin expression with the patient'sclinical-pathological features were also examined. RESULTS: The positive staining of clusterin in different colorectal tissues was primarily a cytoplasmic pattern. Cytoplasmic overexpression of clusterin was detected in none of the normal coloredal mucosa, 17% of the adenomas, 46% of the primary CRCs, and 57% of the CRC metastatic lesions. In addition, a significant positive correlation between overexpression of clusterin and advanced clinical (Dukes) stage was observed (P<0.01). Overexpression of cytoplasmic clusterin in CRCs was inversely correlated with tumor apoptotic index (P<0.01), indicating the anti apoptotic function of cytoplasmic clusterin in CRCs.CONCLUSION: These data suggests that overexpression of cytoplasmic dustin might be involved in the tumorigenesis and/or progression of CRCs. The anti-apoptotic function of cytoplasmic dusterin may be responsible, at least in part, for the development and biologically aggressive behavior of CRC.

  1. Marginal estimation for multi-stage models: waiting time distributions and competing risks analyses.

    Science.gov (United States)

    Satten, Glen A; Datta, Somnath

    2002-01-15

    We provide non-parametric estimates of the marginal cumulative distribution of stage occupation times (waiting times) and non-parametric estimates of marginal cumulative incidence function (proportion of persons who leave stage j for stage j' within time t of entering stage j) using right-censored data from a multi-stage model. We allow for stage and path dependent censoring where the censoring hazard for an individual may depend on his or her natural covariate history such as the collection of stages visited before the current stage and their occupation times. Additional external time dependent covariates that may induce dependent censoring can also be incorporated into our estimates, if available. Our approach requires modelling the censoring hazard so that an estimate of the integrated censoring hazard can be used in constructing the estimates of the waiting times distributions. For this purpose, we propose the use of an additive hazard model which results in very flexible (robust) estimates. Examples based on data from burn patients and simulated data with tracking are also provided to demonstrate the performance of our estimators.

  2. A multistage crucible of revision and approval shapes IPCC policymaker summaries.

    Science.gov (United States)

    Mach, Katharine J; Freeman, Patrick T; Mastrandrea, Michael D; Field, Christopher B

    2016-08-01

    Intergovernmental Panel on Climate Change (IPCC) member governments approve each report's summary for policymakers (SPM) by consensus, discussing and agreeing on each sentence in a plenary session with scientist authors. A defining feature of IPCC assessment, the governmental approval process builds joint ownership of current knowledge by scientists and governments. The resulting SPM revisions have been extensively discussed in anecdotes, interviews, and perspectives, but they have not been comprehensively analyzed. We provide an in-depth evaluation of IPCC SPM revisions, establishing an evidential basis for understanding their nature. Revisions associated with governmental review and approval generally expand SPMs, with SPM text growing by 17 to 53% across recent assessment reports. Cases of high political sensitivity and failure to reach consensus are notable exceptions, resulting in SPM contractions. In contrast to recent claims, we find that IPCC SPMs are as readable, for multiple metrics of reading ease, as other professionally edited assessment summaries. Across reading-ease metrics, some SPMs become more readable through governmental review and approval, whereas others do not. In an SPM examined through the entire revision process, most revisions associated with governmental review and approval occurred before the start of the government-approval plenary session. These author revisions emphasize clarity, scientific rigor, and explanation. In contrast, the subsequent plenary revisions place greater emphasis especially on policy relevance, comprehensiveness of examples, and nuances of expert judgment. Overall, the value added by the IPCC process emerges in a multistage crucible of revision and approval, as individuals together navigate complex science-policy terrain.

  3. Contact force and mechanical loss of multistage cable under tension and bending

    Science.gov (United States)

    Ru, Yanyun; Yong, Huadong; Zhou, Youhe

    2016-07-01

    A theoretical model for calculating the stress and strain states of cabling structures with different loadings has been developed in this paper. We solve the problem for the first- and second-stage cable with tensile or bending strain. The contact and friction forces between the strands are presented by two-dimensional contact model. Several theoretical models have been proposed to verify the results when the triplet subjected to the tensile strain, including contact force, contact stresses, and mechanical loss. It is found that loadings will affect the friction force and the mechanical loss of the triplet. The results show that the contact force and mechanical loss are dependent on the twist pitch. A shorter twist pitch can lead to higher contact force, while the trend of mechanical loss with twist pitch is complicated. The mechanical loss may be reduced by adjusting the twist pitch reasonably. The present model provides a simple analysis method to investigate the mechanical behaviors in multistage-structures under different loads.

  4. Multiobjective Optimization of Low-Specific-Speed Multistage Pumps by Using Matrix Analysis and CFD Method

    Directory of Open Access Journals (Sweden)

    Qiaorui Si

    2013-01-01

    Full Text Available The implementation of energy-saving and emission-reduction techniques has become a worldwide consensus. Thus, special attention should be provided to the field of pump optimization. With the objective of focusing on multiobjective optimization problems in low-specific-speed pumps, 10 parameters were carefully selected in this study for an L27(310 orthogonal experiment. The parameters include the outlet width of the impeller blade, blade number, and inlet setting angle of the guide vane. The numerical calculation appropriate for forecasting the performance of multistage pumps, such as the head, efficiency, and shaft power, was analyzed. Results were obtained after calculating the two-stage flow field of the pump through computational fluid dynamics (CFD methods. A matrix method was proposed to optimize the results of the orthographic experiment. The optimal plan was selected according to the weight of each factor. Calculated results indicate that the inlet setting angle of the guide vane influences efficiency significantly and that the outlet angle of blades has an effect on the head and shaft power. A prototype was produced with the optimal plan for testing. The efficiency rating of the prototype reached 58.61%; maximum shaft power was within the design requirements, which verifies that the proposed method is feasible for pump optimization.

  5. Molecular resolution and fragmentation of fulvic acid by electrospray ionization/multistage tandem mass spectrometry

    Science.gov (United States)

    Leenheer, J.A.; Rostad, C.E.; Gates, Paul M.; Furlong, E.T.; Ferrer, I.

    2001-01-01

    Molecular weight distributions of fulvic acid from the Suwannee River, Georgia, were investigated by electrospray ionization/quadrupole mass spectrometry (ESI/QMS), and fragmentation pathways of specific fulvic acid masses were investigated by electrospray ionization/ion trap multistage tandem mass spectrometry (ESI/MST/MS). ESI/QMS studies of the free acid form of low molecular weight poly(carboxylic acid) standards in 75% methanol/25% water mobile phase found that negative ion detection gave the optimum generation of parent ions that can be used for molecular weight determinations. However, experiments with poly(acrylic acid) mixtures and specific high molecular weight standards found multiply charged negative ions that gave a low bias to molecular mass distributions. The number of negative charges on a molecule is dependent on the distance between charges. ESI/MST/MS of model compounds found characteristic water loss from alcohol dehydration and anhydride formation, as well as CO2 loss from decarboxylation, and CO loss from ester structures. Application of these fragmentation pathways to specific masses of fulvic acid isolated and fragmented by ESI/MST/MS is indicative of specific structures that can serve as a basis for future structural confirmation after these hypothesized structures are synthesized.

  6. Multi-Bed Multi-Stage Adsorption Refrigeration Cycle-Reducing Driving Heat Source Temperature

    Science.gov (United States)

    Alam, K. C. Amanul; Akahira, Akira; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao; Saha, Bidyut Baran; Koyama, Shigeru; Ng, Kim Choon; Chua, Hui Tong

    The study aims at designing a multi-bed multi-stage adsorption chiller that can be driven by waste heat at near ambient temperature. The chiller is designed such a way that it can be switched into different modes depending on the driving heat source temperature. Stage regeneration techniques have been applied to operate the chiller by relatively low temperature heat source. Driving heat source temperature is validated by simulated data and the performances obtained from different modes are compared. In terms of COP (Coefficient of performance),the chiller shows best performance in conventional single-stage mode for driving heat source temperature greater than 60°C, two stage mode for driving source temperature between 42 and 60°C,in three-stage mode for driving source temperature less than 42°C. In terms of cooling capacity, it shows the best performance in single-stage mode for heat source temperature greater than 70°C. The mass recovery process in single-stage mode is also examined. It is seen that the mass recovery process improve cooling capacity significantly, specially for the low regenerating temperature region.

  7. Mathematical models for process commonality under quality and resources breakdown in multistage production

    Institute of Scientific and Technical Information of China (English)

    Mohammed Abdul WAZED; Shamsuddin AHMED; Yusoff Bin NUKMANt

    2011-01-01

    It is essential to manage customers' diverse desires and to keep manufacturing costs as low as possible for survival in competition and eventually in production.Sharing resources in manufacturing for different products is a vital method of accomplishing this goal.The advantages of using a common process in production are stated in the literature.However,the mathematical models as well as simulation or conceptual models are not sufficient.The main objective of this paper is to develop mathematical models for multiproduct and multistage production under quality and breakdown uncertainties.The idea of the process commonality is incorporated in the proposed models.The models are validated by primary data collected from a Malaysian company and comparison of the timely requirement schedules of earlier MRP Ⅱ and the proposed models under stable and perfect production environments.An appreciable convergence of the outcomes is observed.However,the proposed models are carrying additional information about the available locations of the parts in a time frame.After validation,the effects of process commonality on cost,capacity and the requirement schedule under uncertainties are examined.It is observed that the use of common processes in manufacturing is always better than the non-commonality scenario in terms of production cost.However,the increase in capacity requirement for commonality designs is higher for an ideal system,while it is less when the system suffers from breakdowns and a quality problem.

  8. An e-quality control model for multistage machining processes of workpieces

    Institute of Scientific and Technical Information of China (English)

    LIU DaoYu; JIANG PingYu; ZHANG YingFeng

    2008-01-01

    To track and control the changes of process quality attributes in multistage ma-chining processes (MMPs), an e-quality control (e-QC) model is proposed. The e-QC model is defined as a quality information service node with e-formalizing technology, whose input/output and intermediate process (that is IPO) are known to other nodes, and its implemention in MMPs is provided. In order to establish the e-QC model, a measuring network is constructed to acquire the original quality data, and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC, which can be tracked by in-formation template network in real time. Furthermore, a hierarchical control method is adopted to coordinate e-QCs, in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process quality. At last, a prototype is developed to verify the proposed methods.

  9. Slow and velocity-tunable beams of metastable He2 by multistage Zeeman deceleration

    Science.gov (United States)

    Motsch, Michael; Jansen, Paul; Agner, Josef A.; Schmutz, Hansjürg; Merkt, Frédéric

    2014-04-01

    We report on the use of multistage Zeeman deceleration to generate beams of He2 molecules in the metastable a3Σu+ state with velocities tunable down to 100 m/s. The metastable molecules are generated by striking a discharge in a supersonic expansion of pure helium gas from a pulsed valve held at cryogenic temperature. The velocity and internal-state distributions of the metastable He2 molecules are measured for nozzle temperatures of 300, 77, and 10 K by high-resolution photoelectron and photoionization spectroscopy. The deceleration process does not exhibit any rotational state selectivity with rotational levels up to N''=21 being populated, but eliminates molecules in spin-rotational sublevels with J''=N'' from the beam, where J'' and N'' are the total and the rotational angular momentum quantum number, respectively. The lack of rotational state selectivity is attributed to the fact that the Paschen-Back regime of the Zeeman effect in the rotational levels of He2 is already reached at fields of only 0.1 T.

  10. Unified theory for inhomogeneous thermoelectric generators and coolers including multistage devices

    Science.gov (United States)

    Gerstenmaier, York Christian; Wachutka, Gerhard

    2012-11-01

    A novel generalized Lagrange multiplier method for functional optimization with inclusion of subsidiary conditions is presented and applied to the optimization of material distributions in thermoelectric converters. Multistaged devices are considered within the same formalism by inclusion of position-dependent electric current in the legs leading to a modified thermoelectric equation. Previous analytical solutions for maximized efficiencies for generators and coolers obtained by Sherman [J. Appl. Phys.JAPIAU0021-897910.1063/1.1735380 31, 1 (1960)], Snyder [Phys. Rev. B1098-012110.1103/PhysRevB.86.045202 86, 045202 (2012)], and Seifert [Phys. Status Solidi APSSABA0031-896510.1002/pssa.200925460 207, 760 (2010)] by a method of local optimization of reduced efficiencies are recovered by independent proof. The outstanding maximization problems for generated electric power and cooling power can be solved swiftly numerically by solution of a differential equation-system obtained within the new formalism. As far as suitable materials are available, the inhomogeneous TE converters can have increased performance by use of purely temperature-dependent material properties in the thermoelectric legs or by use of purely spatial variation of material properties or by a combination of both. It turns out that the optimization domain is larger for the second kind of device which can, thus, outperform the first kind of device.

  11. Multi-Stage Feature Selection Based Intelligent Classifier for Classification of Incipient Stage Fire in Building

    Directory of Open Access Journals (Sweden)

    Allan Melvin Andrew

    2016-01-01

    Full Text Available In this study, an early fire detection algorithm has been proposed based on low cost array sensing system, utilising off- the shelf gas sensors, dust particles and ambient sensors such as temperature and humidity sensor. The odour or “smellprint” emanated from various fire sources and building construction materials at early stage are measured. For this purpose, odour profile data from five common fire sources and three common building construction materials were used to develop the classification model. Normalised feature extractions of the smell print data were performed before subjected to prediction classifier. These features represent the odour signals in the time domain. The obtained features undergo the proposed multi-stage feature selection technique and lastly, further reduced by Principal Component Analysis (PCA, a dimension reduction technique. The hybrid PCA-PNN based approach has been applied on different datasets from in-house developed system and the portable electronic nose unit. Experimental classification results show that the dimension reduction process performed by PCA has improved the classification accuracy and provided high reliability, regardless of ambient temperature and humidity variation, baseline sensor drift, the different gas concentration level and exposure towards different heating temperature range.

  12. Optimal Control for Multistage Nonlinear Dynamic System of Microbial Bioconversion in Batch Culture

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2011-01-01

    Full Text Available In batch culture of glycerol biodissimilation to 1,3-propanediol (1,3-PD, the aim of adding glycerol is to obtain as much 1,3-PD as possible. Taking the yield intensity of 1,3-PD as the performance index and the initial concentration of biomass, glycerol, and terminal time as the control vector, we propose an optimal control model subject to a multistage nonlinear dynamical system and constraints of continuous state. A computational approach is constructed to seek the solution of the above model. Firstly, we transform the optimal control problem into the one with fixed terminal time. Secondly, we transcribe the optimal control model into an unconstrained one based on the penalty functions and an extension of the state space. Finally, by approximating the control function with simple functions, we transform the unconstrained optimal control problem into a sequence of nonlinear programming problems, which can be solved using gradient-based optimization techniques. The convergence analysis and optimality function of the algorithm are also investigated. Numerical results show that, by employing the optimal control, the concentration of 1,3-PD at the terminal time can be increased, compared with the previous results.

  13. Estimation And Selection Via Absolute Penalized Convex Minimization And Its Multistage Adaptive Applications

    CERN Document Server

    Huang, Jian

    2011-01-01

    The $\\ell_1$-penalized method, or the Lasso, has emerged as an important tool for the analysis of large data sets. Many important results have been obtained for the Lasso in linear regression which have led to a deeper understanding of high-dimensional statistical problems. In this article, we consider a class of weighted $\\ell_1$-penalized estimators for convex loss functions of a general form, including the generalized linear models. We study the estimation, prediction, selection and sparsity properties of the weighted $\\ell_1$-penalized estimator in sparse, high-dimensional settings where the number of predictors $p$ can be much larger than the sample size $n$. Adaptive Lasso is considered as a special case. A multistage method is developed to apply an adaptive Lasso recursively. We provide $\\ell_q$ oracle inequalities, a general selection consistency theorem, and an upper bound on the dimension of the Lasso estimator. Important models including the linear regression, logistic regression and log-linear mod...

  14. Multistage aqueous two-phase extraction of a monoclonal antibody from cell supernatant.

    Science.gov (United States)

    Muendges, Jan; Zalesko, Alexej; Górak, Andrzej; Zeiner, Tim

    2015-01-01

    This article presents results of continuous multistage aqueous two-phase extraction of an immunoglobulin G1 from cell supernatant in a mixer-settler unit. An aqueous two-phase system consisting of polyethylene glycol 2000, phosphate salt, and water was applied without and with sodium chloride (NaCl). Influences of different parameters such as throughput, phase ratio, and stage number on the extraction performance were analyzed. For systems without NaCl, the extraction was carried out as a washing step. An increase of stage number from one to five stages enabled to increase the immunoglobulin G1 purity from 11.8 to 32.6% at a yield of nearly 90%. Furthermore, a reduction of product phase volume due to a higher phase ratio led to an increase of purity from 20.8 to 29.6% in a three-stage countercurrent extraction. For experiments with NaCl moderate partitioning conditions were adjusted by adding 8 wt% NaCl. In that case, the extraction was carried out as a stripping step.

  15. Multi-stage ytterbium fiber-amplifier seeded by a gain-switched laser diode

    CERN Document Server

    Ryser, Manuel; Burn, Andreas; Romano, Valerio

    2014-01-01

    We demonstrated all-fiber amplification of 11 ps pulses from a gain-switched laser diode at 1064 nm. The diode was driven at a repetition rate of 40 MHz and delivered 13 $\\mu$W of fiber-coupled average output power. For the low output pulse energy of 325 fJ we have designed a multi-stage core pumped pre-amplifier in order to keep the contribution of undesired amplified spontaneous emission as low as possible. By using a novel time-domain approach for determining the power spectral density ratio (PSD) of signal to noise, we identified the optimal working point for our pre-amplifier. After the pre-amplifier we reduced the 40 MHz repetition rate to 1 MHz using a fiber coupled pulse-picker. The final amplification was done with a cladding pumped Yb-doped large mode area fiber and a subsequent Yb-doped rod-type fiber. With our setup we reached a total gain of 73 dB, resulting in pulse energies of >5.6 $\\mu$J and peak powers of >0.5 MW. The average PSD-ratio of signal to noise we determined to be 18/1 at the output...

  16. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    Directory of Open Access Journals (Sweden)

    L. D. Sánchez

    2012-12-01

    Full Text Available This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF in a multi-stage filtration (MSF plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%. Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

  17. A simple multistage closed-(box+reservoir model of chemical evolution

    Directory of Open Access Journals (Sweden)

    Caimmi R.

    2011-01-01

    Full Text Available Simple closed-box (CB models of chemical evolution are extended on two respects, namely (i simple closed-(box+reservoir (CBR models allowing gas outflow from the box into the reservoir (Hartwick 1976 or gas inflow into the box from the reservoir (Caimmi 2007 with rate proportional to the star formation rate, and (ii simple multistage closed-(box+reservoir (MCBR models allowing different stages of evolution characterized by different inflow or outflow rates. The theoretical differential oxygen abundance distribution (TDOD predicted by the model maintains close to a continuous broken straight line. An application is made where a fictitious sample is built up from two distinct samples of halo stars and taken as representative of the inner Galactic halo. The related empirical differential oxygen abundance distribution (EDOD is represented, to an acceptable extent, as a continuous broken line for two viable [O/H]-[Fe/H] empirical relations. The slopes and the intercepts of the regression lines are determined, and then used as input parameters to MCBR models. Within the errors (-+σ, regression line slopes correspond to a large inflow during the earlier stage of evolution and to low or moderate outflow during the subsequent stages. A possible inner halo - outer (metal-poor bulge connection is also briefly discussed. Quantitative results cannot be considered for applications to the inner Galactic halo, unless selection effects and disk contamination are removed from halo samples, and discrepancies between different oxygen abundance determination methods are explained.

  18. Development of a 4 MV Laser-Triggered Multi-Stage Switch

    Institute of Scientific and Technical Information of China (English)

    LI Hongtao; DENG Jianjun; WANG Yujuan; FENG Shuping; XIE Weiping; DING Sonan

    2008-01-01

    A 22-stage 4 MV laser-triggered multistage multi-channel switch (LTS) was designed according to the hypothesis that the well-proportioned electrical field distribution is helpful in reducing the jitter of delay. Field distribution in the switch section is regulated by a metal field regulation ring and several gradient rings. In order to reduce the jitter further, a SF6/N2 mixture is chosen as the switching medium. The generalized standard deviation of the self-breakdown voltage and the deviation of the average value from the prediction is less than 4.4% and 13% respectively. Linearity of the self-breakdown voltage is better than 0.95. Triggered by a laser pulse of 35 mJ/3 ns, the delay is about 26 ns at a working voltage of 85%±3% USB (Self-breakdown Voltage). Maximum deviation of delay is less than ±2.5 ns. Jitter is less than 1.5 ns. The delay and jitter decrease with the increase in the working ratio (the ratio of working voltage to USB), pressure or voltage.

  19. Catalytic multi-stage liquefaction of coal at HTI: Bench-scale studies in coal/waste plastics coprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, V.R.; Lee, L.K.; Stalzer, R.H. [Hydrocarbon Technologies, Inc., Lawrenceville, NJ (United States)] [and others

    1995-12-31

    The development of Catalytic Multi-Stage Liquefaction (CMSL) at HTI has focused on both bituminous and sub-bituminous coals using laboratory, bench and PDU scale operations. The crude oil equivalent cost of liquid fuels from coal has been curtailed to about $30 per barrel, thus achieving over 30% reduction in the price that was evaluated for the liquefaction technologies demonstrated in the late seventies and early eighties. Contrary to the common belief, the new generation of catalytic multistage coal liquefaction process is environmentally very benign and can produce clean, premium distillates with a very low (<10ppm) heteroatoms content. The HTI Staff has been involved over the years in process development and has made significant improvements in the CMSL processing of coals. A 24 month program (extended to September 30, 1995) to study novel concepts, using a continuous bench scale Catalytic Multi-Stage unit (30kg coal/day), has been initiated since December, 1992. This program consists of ten bench-scale operations supported by Laboratory Studies, Modelling, Process Simulation and Economic Assessments. The Catalytic Multi-Stage Liquefaction is a continuation of the second generation yields using a low/high temperature approach. This paper covers work performed between October 1994- August 1995, especially results obtained from the microautoclave support activities and the bench-scale operations for runs CMSL-08 and CMSL-09, during which, coal and the plastic components for municipal solid wastes (MSW) such as high density polyethylene (HDPE)m, polypropylene (PP), polystyrene (PS), and polythylene terphthlate (PET) were coprocessed.

  20. Effect of proton-conduction in electrolyte on electric efficiency of multi-stage solid oxide fuel cells.

    Science.gov (United States)

    Matsuzaki, Yoshio; Tachikawa, Yuya; Somekawa, Takaaki; Hatae, Toru; Matsumoto, Hiroshige; Taniguchi, Shunsuke; Sasaki, Kazunari

    2015-07-28

    Solid oxide fuel cells (SOFCs) are promising electrochemical devices that enable the highest fuel-to-electricity conversion efficiencies under high operating temperatures. The concept of multi-stage electrochemical oxidation using SOFCs has been proposed and studied over the past several decades for further improving the electrical efficiency. However, the improvement is limited by fuel dilution downstream of the fuel flow. Therefore, evolved technologies are required to achieve considerably higher electrical efficiencies. Here we present an innovative concept for a critically-high fuel-to-electricity conversion efficiency of up to 85% based on the lower heating value (LHV), in which a high-temperature multi-stage electrochemical oxidation is combined with a proton-conducting solid electrolyte. Switching a solid electrolyte material from a conventional oxide-ion conducting material to a proton-conducting material under the high-temperature multi-stage electrochemical oxidation mechanism has proven to be highly advantageous for the electrical efficiency. The DC efficiency of 85% (LHV) corresponds to a net AC efficiency of approximately 76% (LHV), where the net AC efficiency refers to the transmission-end AC efficiency. This evolved concept will yield a considerably higher efficiency with a much smaller generation capacity than the state-of-the-art several tens-of-MW-class most advanced combined cycle (MACC).

  1. Regional-scale electric power system planning under uncertainty-A multistage interval-stochastic integer linear programming approach

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.F. [Energy and Environmental Research Center, North China Electric Power University, Beijing 102206 (China); Huang, G.H., E-mail: gordon.huang@uregina.c [Environmental Systems Engineering Program, Faculty of Engineering, University of Regina, Regina, Saskatchewan, S4S 0A2 (Canada); College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Li, Y.P. [College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Xu, Y.; Chen, W.T. [Energy and Environmental Research Center, North China Electric Power University, Beijing 102206 (China)

    2010-01-15

    In this study, a multistage interval-stochastic regional-scale energy model (MIS-REM) is developed for supporting electric power system (EPS) planning under uncertainty that is based on a multistage interval-stochastic integer linear programming method. The developed MIS-REM can deal with uncertainties expressed as both probability distributions and interval values existing in energy system planning problems. Moreover, it can reflect dynamic decisions for electricity generation schemes and capacity expansions through transactions at discrete points of a multiple representative scenario set over a multistage context. It can also analyze various energy-policy scenarios that are associated with economic penalties when the regulated targets are violated. A case study is provided for demonstrating the applicability of the developed model, where renewable and non-renewable energy resources, economic concerns, and environmental requirements are integrated into a systematic optimization process. The results obtained are helpful for supporting (a) adjustment or justification of allocation patterns of regional energy resources and services, (b) formulation of local policies regarding energy consumption, economic development, and energy structure, and (c) analysis of interactions among economic cost, environmental requirement, and energy-supply security.

  2. Regional-scale electric power system planning under uncertainty. A multistage interval-stochastic integer linear programming approach

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.F.; Xu, Y.; Chen, W.T. [Energy and Environmental Research Center, North China Electric Power University, Beijing 102206 (China); Huang, G.H. [Environmental Systems Engineering Program, Faculty of Engineering, University of Regina, Regina, Saskatchewan (Canada); College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Li, Y.P. [College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

    2010-01-15

    In this study, a multistage interval-stochastic regional-scale energy model (MIS-REM) is developed for supporting electric power system (EPS) planning under uncertainty that is based on a multistage interval-stochastic integer linear programming method. The developed MIS-REM can deal with uncertainties expressed as both probability distributions and interval values existing in energy system planning problems. Moreover, it can reflect dynamic decisions for electricity generation schemes and capacity expansions through transactions at discrete points of a multiple representative scenario set over a multistage context. It can also analyze various energy-policy scenarios that are associated with economic penalties when the regulated targets are violated. A case study is provided for demonstrating the applicability of the developed model, where renewable and non-renewable energy resources, economic concerns, and environmental requirements are integrated into a systematic optimization process. The results obtained are helpful for supporting (a) adjustment or justification of allocation patterns of regional energy resources and services, (b) formulation of local policies regarding energy consumption, economic development, and energy structure, and (c) analysis of interactions among economic cost, environmental requirement, and energy-supply security. (author)

  3. Pilot-scale multistage membrane process for the separation of CO2 from LNG-fired flue gas

    KAUST Repository

    Choi, Seung Hak

    2013-06-01

    In this study, a multistage pilot-scale membrane plant was constructed and operated for the separation of CO2 from Liquefied Natural Gas (LNG)-fired boiler flue gas of 1000 Nm3/day. The target purity and recovery of CO2 were 99 vol.% and 90%, respectively. For this purpose, asymmetric polyethersulfone (PES) hollow fibers membranes has been developed in our previous work and has evaluated the effects of operating pressure and feed concentration of CO2 on separation performance. The operating and permeation data obtained were also analyzed in relation with the numerical simulation data using countercurrent flow model. Based on these results, in this study, four-staged membrane process including dehumidification process has been designed, installed, and operated to demonstrate the feasibility of multistage membrane systems for removing CO2 from flue gases. The operation results using this plant were compared to the numerical simulation results on multistage membrane process. The experimental results matched well with the numerical simulation data. The concentration and the recovery of CO2 in the permeate stream of final stage were ranged from 95-99 vol.% and 70-95%, respectively, depending on the operating conditions. This study demonstrated the applicability of the membrane-based pilot plant for CO2 recovery from flue gas. © 2013 Elsevier B.V. All rights reserved.

  4. Effect Analysis of Geometric Parameters on Stainless Steel Stamping Multistage Pump by Experimental Test and Numerical Calculation

    Directory of Open Access Journals (Sweden)

    Chuan Wang

    2013-01-01

    Full Text Available In order to improve the efficiency of stainless steel stamping multistage pump, quadratic regression orthogonal test, hydraulic design, and computational fluid dynamics (CFD are used to analyze the effect of pump geometric parameters. Sixteen impellers are designed based on the quadratic regression orthogonal test, which have three factors including impeller outlet slope, impeller blade outlet stagger angle, and impeller blade outlet width. Through quadratic regression equation, the function relationship between efficiency values and three factors is established. The optimal combination of geometric parameters is found through the analysis of the regression equation. To further study the influence of blade thickness on the performance of multistage pump, numerical simulations of multistage pump with different blade thicknesses are carried out. The influence law of blade thickness on pump performance is built from the external characteristics and internal flow field. In conclusion, with the increase of blade thickness, the best efficiency point of the pump shifts to the small flow rate direction, and the vortex regions inside the pump at rated flow gradually increase, which is the main reason that pump efficiency decreases along with the increase of the blade thickness at rated flow.

  5. Venture Investment Incentive Mechanisms and Simulation with Venture Entrepreneurs Having Multistage Efforts Based on Fairness Preference Theory

    Directory of Open Access Journals (Sweden)

    Kaihong Wang

    2016-01-01

    Full Text Available When venture capital has been invested into venture companies, venture capitalists and venture entrepreneurs form a principal-agent relationship. Take into account the fact that the venture entrepreneur’s effort is a long process, because the effort is not the same at different stage. Therefore, efforts variables are seen as the multistage dynamic variable, and venture investment principal-agent model with venture entrepreneurs having multistage efforts is constructed on the basis of the classic principal-agent theory in the paper. Further, in the later stage effort of venture entrepreneurs is affected by the size of prestage benefit with venture capitalists and venture entrepreneurs; thus the fairness preference model is improved, and venture investment principal-agent model with venture entrepreneurs having multistage efforts is constructed on the basis of fairness preference theory. Both theoretical derivation and simulation have demonstrated that, under the condition of information asymmetry, if the fairness preference of venture entrepreneurs holds, then (1 venture capitalists provide venture entrepreneurs with level higher than that without fairness preference, (2 in every single stage venture entrepreneurs make efforts higher than those without fairness preference, and (3 in two periods both venture investors and venture entrepreneurs gain total real gains higher than those in two periods without fair preference.

  6. A risk-based interactive multi-stage stochastic programming approach for water resources planning under dual uncertainties

    Science.gov (United States)

    Wang, Y. Y.; Huang, G. H.; Wang, S.; Li, W.; Guan, P. B.

    2016-08-01

    In this study, a risk-based interactive multi-stage stochastic programming (RIMSP) approach is proposed through incorporating the fractile criterion method and chance-constrained programming within a multi-stage decision-making framework. RIMSP is able to deal with dual uncertainties expressed as random boundary intervals that exist in the objective function and constraints. Moreover, RIMSP is capable of reflecting dynamics of uncertainties, as well as the trade-off between the total net benefit and the associated risk. A water allocation problem is used to illustrate applicability of the proposed methodology. A set of decision alternatives with different combinations of risk levels applied to the objective function and constraints can be generated for planning the water resources allocation system. The results can help decision makers examine potential interactions between risks related to the stochastic objective function and constraints. Furthermore, a number of solutions can be obtained under different water policy scenarios, which are useful for decision makers to formulate an appropriate policy under uncertainty. The performance of RIMSP is analyzed and compared with an inexact multi-stage stochastic programming (IMSP) method. Results of comparison experiment indicate that RIMSP is able to provide more robust water management alternatives with less system risks in comparison with IMSP.

  7. The influence of the "cage effect" on the mechanism of reversible bimolecular multistage chemical reactions in solutions.

    Science.gov (United States)

    Doktorov, Alexander B

    2015-08-21

    Manifestations of the "cage effect" at the encounters of reactants are theoretically treated by the example of multistage reactions in liquid solutions including bimolecular exchange reactions as elementary stages. It is shown that consistent consideration of quasi-stationary kinetics of multistage reactions (possible only in the framework of the encounter theory) for reactions proceeding near reactants contact can be made on the basis of the concepts of a "cage complex." Though mathematically such a consideration is more complicated, it is more clear from the standpoint of chemical notions. It is established that the presence of the "cage effect" leads to some important effects not inherent in reactions in gases or those in solutions proceeding in the kinetic regime, such as the appearance of new transition channels of reactant transformation that cannot be caused by elementary event of chemical conversion for the given mechanism of reaction. This results in that, for example, rate constant values of multistage reaction defined by standard kinetic equations of formal chemical kinetics from experimentally measured kinetics can differ essentially from real values of these constants.

  8. Effect of proton-conduction in electrolyte on electric efficiency of multi-stage solid oxide fuel cells

    Science.gov (United States)

    Matsuzaki, Yoshio; Tachikawa, Yuya; Somekawa, Takaaki; Hatae, Toru; Matsumoto, Hiroshige; Taniguchi, Shunsuke; Sasaki, Kazunari

    2015-07-01

    Solid oxide fuel cells (SOFCs) are promising electrochemical devices that enable the highest fuel-to-electricity conversion efficiencies under high operating temperatures. The concept of multi-stage electrochemical oxidation using SOFCs has been proposed and studied over the past several decades for further improving the electrical efficiency. However, the improvement is limited by fuel dilution downstream of the fuel flow. Therefore, evolved technologies are required to achieve considerably higher electrical efficiencies. Here we present an innovative concept for a critically-high fuel-to-electricity conversion efficiency of up to 85% based on the lower heating value (LHV), in which a high-temperature multi-stage electrochemical oxidation is combined with a proton-conducting solid electrolyte. Switching a solid electrolyte material from a conventional oxide-ion conducting material to a proton-conducting material under the high-temperature multi-stage electrochemical oxidation mechanism has proven to be highly advantageous for the electrical efficiency. The DC efficiency of 85% (LHV) corresponds to a net AC efficiency of approximately 76% (LHV), where the net AC efficiency refers to the transmission-end AC efficiency. This evolved concept will yield a considerably higher efficiency with a much smaller generation capacity than the state-of-the-art several tens-of-MW-class most advanced combined cycle (MACC).

  9. Modeling the effect of unsteady flows on the time average flow field of a blade row embedded in an axial flow multistage turbomachine

    Science.gov (United States)

    Adamczyk, John J.

    1996-01-01

    The role of unsteady flow processes in establishing the performance of axial flow turbomachinery was investigated. The development of the flow model, as defined by the time average flow equations associated with the passage of the blade row embedded in a multistage configuration, is presented. The mechanisms for unsteady momentum and energy transport is outlined. The modeling of the unsteady momentum and energy transport are discussed. The procedure for simulating unsteady multistage turbomachinery flows is described.

  10. Intelligent Search Method Based ACO Techniques for a Multistage Decision Problem EDP/LFP

    Directory of Open Access Journals (Sweden)

    Mostefa RAHLI

    2006-07-01

    Full Text Available The implementation of a numerical library of calculation based optimization in electrical supply networks area is in the centre of the current research orientations, thus, our project in a form given is centred on the development of platform NMSS1. It's a software environment which will preserve many efforts as regards calculations of charge, smoothing curves, losses calculation and economic planning of the generated powers [23].The operational research [17] in a hand and the industrial practice in the other, prove that the means and processes of simulation reached a level of very appreciable reliability and mathematical confidence [4, 5, 14]. It is of this expert observation that many processes make confidence to the results of simulation.The handicaps of this approach or methodology are that it makes base its judgments and handling on simplified assumptions and constraints whose influence was deliberately neglected to be added to the cost to spend [14].By juxtaposing the methods of simulation with artificial intelligence techniques, gathering set of numerical methods acquires an optimal reliability whose assurance can not leave doubt.Software environment NMSS [23] can be a in the field of the rallying techniques of simulation and electric network calculation via a graphic interface. In the same software integrate an AI capability via a module expert system.Our problem is a multistage case where are completely dependant and can't be performed separately.For a multistage problem [21, 22], the results obtained from a credible (large size problem calculation, makes the following question: Could choice of numerical methods set make the calculation of a complete problem using more than two treatments levels, a total error which will be the weakest one possible? It is well-known according to algorithmic policy; each treatment can be characterized by a function called mathematical complexity. This complexity is in fact a coast (a weight overloading

  11. Improved Quality Prediction Model for Multistage Machining Process Based on Geometric Constraint Equation

    Institute of Scientific and Technical Information of China (English)

    ZHU Limin; HE Gaiyun; SONG Zhanjie

    2016-01-01

    Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process (MMP). However, due to the variation accumulation and propagation, it becomes quite difficult to predict and reduce product variation for MMP. While the method of statistical process control can be used to control product quality, it is used mainly to monitor the process change rather than to analyze the cause of product variation. In this paper, based on a differential description of the contact kinematics of locators and part surfaces, and the geometric constraints equation defined by the locating scheme, an improved analytical variation propagation model for MMP is presented. In which the influence of both locator position and machining error on part quality is considered while, in traditional model, it usually focuses on datum error and fixture error. Coordinate transformation theory is used to reflect the generation and transmission laws of error in the establishment of the model. The concept of deviation matrix is heavily applied to establish an explicit mapping between the geometric deviation of part and the process error sources. In each machining stage, the part deviation is formulized as three separated components corresponding to three different kinds of error sources, which can be further applied to fault identification and design optimization for complicated machining process. An example part for MMP is given out to validate the effectiveness of the methodology. The experiment results show that the model prediction and the actual measurement match well. This paper provides a method to predict part deviation under the influence of fixture error, datum error and machining error, and it enriches the way of quality prediction for MMP.

  12. Analysis of experimental characteristics of multistage steam-jet electors of steam turbines

    Science.gov (United States)

    Aronson, K. E.; Ryabchikov, A. Yu.; Brodov, Yu. M.; Brezgin, D. V.; Zhelonkin, N. V.; Murmanskii, I. B.

    2017-02-01

    A series of questions for specification of physical gas dynamics model in flow range of steam-jet unit and ejector computation methodology, as well as functioning peculiarities of intercoolers, was formulated based on analysis of experimental characteristics of multistage team-jet steam turbines. It was established that coefficient defining position of critical cross-section of injected flow depends on characteristics of the "sound tube" zone. Speed of injected flow within this tube may exceed that of sound, and pressure jumps in work-steam decrease at the same time. Characteristics of the "sound tube" define optimal axial sizes of the ejector. According to measurement results, the part of steam condensing in the first-stage coolant constitutes 70-80% of steam amount supplied into coolant and is almost independent of air content in steam. Coolant efficiency depends on steam pressure defined by operation of steam-jet unit of ejector of the next stage after coolant of steam-jet stage, temperature, and condensing water flow. As a rule, steam entering content of steam-air mixture supplied to coolant is overheated with respect to saturation temperature of steam in the mixture. This should be taken into account during coolant computation. Long-term operation causes changes in roughness of walls of the ejector's mixing chamber. The influence of change of wall roughness on ejector characteristic is similar to the influence of reverse pressure of the steam-jet stage. Until some roughness value, injection coefficient of the ejector stage operating in superlimiting regime hardly changed. After reaching critical roughness, the ejector switches to prelimiting operating regime.

  13. Multistage modeling of protein dynamics with monomeric Myc oncoprotein as an example

    Science.gov (United States)

    Liu, Jiaojiao; Dai, Jin; He, Jianfeng; Niemi, Antti J.; Ilieva, Nevena

    2017-03-01

    We propose to combine a mean-field approach with all-atom molecular dynamics (MD) into a multistage algorithm that can model protein folding and dynamics over very long time periods yet with atomic-level precision. As an example, we investigate an isolated monomeric Myc oncoprotein that has been implicated in carcinomas including those in colon, breast, and lungs. Under physiological conditions a monomeric Myc is presumed to be an example of intrinsically disordered proteins that pose a serious challenge to existing modeling techniques. We argue that a room-temperature monomeric Myc is in a dynamical state, it oscillates between different conformations that we identify. For this we adopt the C α backbone of Myc in a crystallographic heteromer as an initial ansatz for the monomeric structure. We construct a multisoliton of the pertinent Landau free energy to describe the C α profile with ultrahigh precision. We use Glauber dynamics to resolve how the multisoliton responds to repeated increases and decreases in ambient temperature. We confirm that the initial structure is unstable in isolation. We reveal a highly degenerate ground-state landscape, an attractive set towards which Glauber dynamics converges in the limit of vanishing ambient temperature. We analyze the thermal stability of this Glauber attractor using room-temperature molecular dynamics. We identify and scrutinize a particularly stable subset in which the two helical segments of the original multisoliton align in parallel next to each other. During the MD time evolution of a representative structure from this subset, we observe intermittent quasiparticle oscillations along the C-terminal α helix, some of which resemble a translating Davydov's Amide-I soliton. We propose that the presence of oscillatory motion is in line with the expected intrinsically disordered character of Myc.

  14. Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

    Directory of Open Access Journals (Sweden)

    Babayigit Osman

    2015-01-01

    Full Text Available Nowadays, single and multistage centrifugal pumps are widely used in industrial and mining enterprises. One of the most important components of a centrifugal pump is the impeller. The performance characteristics are related to the pump comprising the head and the overall efficiency rely a great deal on the impeller geometry. In this work, effects of blade exit angle change on hydraulic efficiency of a multi stage pump impeller are investigated via Ansys-Fluent computational fluid dynamics software for constant width impeller entrance and exit gates, blade numbers and blade thickness. Firstly, the flow volume of a centrifugal pump impeller is generated and then mesh structure is formed for the full impeller flow volume. Secondly, rotational periodic flow model are adopted in order to examine the effect of periodic flow assumption on the performance predictions. Corresponding to the available experimental data, inlet mass flow rate, outlet static pressure and rotation of impeller are taken as 0.02m3s-1, 450 kPa and 2950 rpm, respectively for the water fluid. No slip boundary condition is exposed to all solid of surface in the flow volume. The continuity and Navier-Stokes equations with the k-ε turbulence model and the standard wall functions are used. During the study, numerical analyses are conducted for the blade exit angle values of 18°, 20°, 25°, 30° and 35°. In consequence of the performed analyses, it is determined that hydraulic efficiency of the pump impeller value is changed between 81.0-84.6%. The most convenient blade exit angle that yields 84.6% hydraulic efficiency at is 18°. The obtained results show that the blade exit angle range has an impact on the centrifugal pump performance describing the pump head and the hydraulic efficiency.

  15. Enhancing chemotherapy response with sustained EphA2 silencing using multistage vector delivery

    Science.gov (United States)

    Shen, Haifa; Rodriguez-Aguayo, Cristian; Xu, Rong; Gonzalez-Villasana, Vianey; Mai, Junhua; Huang, Yi; Zhang, Guodong; Guo, Xiaojing; Bai, Litao; Qin, Guoting; Deng, Xiaoyong; Li, Qingpo; Erm, Donald R.; Liu, Xuewu; Sakamoto, Jason; Chavez-Reyes, Arturo; Han, Hee-Dong; Sood, Anil K.; Ferrari, Mauro; Lopez-Berestein, Gabriel

    2013-01-01

    Purpose RNA interference has the potential to specifically knock down the expression of target genes, and thereby transform cancer therapy. However, lack of effective delivery of small inhibitory RNA (siRNA) has dramatically limited its in vivo applications. We have developed a multistage vector (MSV) system, composed of discoidal porous silicon particles loaded with nanotherapeutics, that directs effective delivery and sustained release of siRNA in tumor tissues. In this study, we evaluated therapeutic efficacy of MSV-loaded EphA2 siRNA (MSV/EphA2) with murine orthotopic models of metastatic ovarian cancers as a first step towards development of a new class of nanotherapeutics for the treatment of ovarian cancer. Experimental design Tumor accumulation of MSV/EphA2 and sustained release of siRNA from MSV were analyzed after i.v. administration of MSV/siRNA. Nude mice with metastatic SKOV3ip2 tumors were treated with MSV/EphA2 and paclitaxel, and therapeutic efficacy was assessed. Mice with chemotherapy-resistant HeyA8 ovarian tumors were treated with a combination of MSV/EphA2 and docetaxel, and enhanced therapeutic efficacy was evaluated. Results Treatment of SKOV3ip2 tumor mice with MSV/EphA2 biweekly for 6 weeks resulted in dose-dependent (5, 10 and 15 μg/mice) reduction of tumor weight (36%, 64%, and 83%) and number of tumor nodules compared with the control groups. In addition, tumor growth was completely inhibited when mice were treated with MSV/EphA2 in combination with paclitaxel. Furthermore, combination treatment with MSV/EphA2 and docetaxel inhibited growth of HeyA8-MDR tumors, which were otherwise resistant to docetaxel treatment. Conclusion These findings indicate that MSV/EphA2 merits further development as a novel therapeutic agent for ovarian cancer. PMID:23386691

  16. Seepage flow behaviors of multi-stage fractured horizontal wells in arbitrary shaped shale gas reservoirs

    Science.gov (United States)

    Zhao, Yu-Long; Shan, Bao-Chao; Zhang, Lie-Hui; Liu, Qi-Guo

    2016-10-01

    The horizontal well incorporated with massive hydraulic fracturing has become a key and necessary technology to develop shale gas reservoirs efficiently, and transient pressure analysis is a practical method to evaluate the effectiveness of the fracturing. Until now, however, the related studies on the pressure of such wells have mainly focused on regular outer-boundaries, such as infinite, circular and rectangular boundary shapes, which do not always fulfill the practical conditions and, of course, could cause errors. By extending the boundary element method (BEM) into the application of multi-staged fractured horizontal wells, this paper presents a way of analyzing the transient pressure in arbitrary shaped shale gas reservoirs considering ad-/de-sorption and diffusion of the shale gas with the ‘tri-porosity’ mechanism model. The boundary integral equation can be obtained by coupling the fundamental solution of the Helmholtz equation with the dimensionless diffusivity equation. After discretizing the outer-boundaries and the fractures, the boundary integral equations are linearized and the coefficient matrix of the pressure on the boundaries is assembled, after which bottom-hole pressure can be calculated conveniently. Comparing the BEM solution with semi-analytical solution cases, the accuracy of the new solution can be validated. Then, the characteristic curves of the dimensionless pseudo pressure, as well as its derivative for a well in shale gas reservoirs, are drawn, based on which the parameters’ sensitivity analyses are also conducted. This paper not only enriches the well testing theory and method in shale gas reservoirs, but also provides an effective method to solve problems with complex inner- and outer-boundaries.

  17. Due-date assignment for multi-server multi-stage assembly systems

    Science.gov (United States)

    Yaghoubi, Saeed

    2015-05-01

    In this paper, we attempt to present a constant due-date assignment policy in a multi-server multi-stage assembly system. This system is modelled as a queuing network, where new product orders are entered into the system according to a Poisson process. It is assumed that only one type of product is produced by the production system and multi-servers can be settled in each service station. Each operation of every work is operated at a devoted service station with only one of the servers located at a node of the network based on first come, first served (FCFS) discipline, while the processing times are independent random variables with exponential distributions. It is also assumed that the transport times between each pair of service stations are independent random variables with generalised Erlang distributions. Each product's end result has a penalty cost that is some linear function of its due date and its actual lead time. The due date is calculated by adding a constant to the time that the order enters into the system. Indeed, this constant value is decided at the beginning of the time horizon and is the constant lead time that a product might expect between the time of placing the order and the time of delivery. For computing the due date, we first convert the queuing network into a stochastic network with exponentially distributed arc lengths. Then, by constructing an appropriate finite-state continuous-time Markov model, a system of differential equations is created to find the manufacturing lead-time distribution for any particular product, analytically. Finally, the constant due date for delivery time is obtained by using a linear function of its due date and minimising the expected aggregate cost per product.

  18. Leaching characteristics of poultry litter in first phase of multistage anaerobic digestion

    Directory of Open Access Journals (Sweden)

    Surya P Sunkavalli

    2014-05-01

    Full Text Available Poultry litter is highly biodegradable in nature. Therefore, it could be subjected to biomethanation to produce valuable biogas and bio-manure as byproducts. Some studies have been conducted along these lines in India by utilizing the poultry litter as a substrate in batch type dung digesters of KVIC and DENABANDHU models. However, these reactors have the drawbacks of high residence time (30 – 35 days, scum formation problems etc. Moreover, these batch type plants are not suitable for the treatment of large quantities of solid waste. Multistage anaerobic digestion has the potential to overcome some of the aforesaid issues. Anaerobic leaching experiments were conducted at different total solids concentration and pH using poultry litter in order to evaluate the leachate quality for a period of 7 days. The increase in Total solids (TS % from 15 to 20% show inverse effect on VFA and Alkalinity. The change in pH from 8.5 to 5.5 didn’t show much impact on VFA but there is a small impact on alkalinity. It was also observed that the leaching of the organic matter in the solid to the liquid phase is very fast and it is taking place approximately in three to four days and subsequently leachate getting saturated. Therefore, reactor set up was made in the last phase to regularly remove the water from the reactor so that higher driving force is available for leaching. The study resulted in leaching of maximum organic content in the solid to liquid within three days. DOI: http://dx.doi.org/10.3126/ije.v3i2.10516 International Journal of the Environment Vol.3(2 2014: 76-82

  19. A Palaeoproterozoic multi-stage hydrothermal alteration system at Nalunaq gold deposit, South Greenland

    Science.gov (United States)

    Bell, Robin-Marie; Kolb, Jochen; Waight, Tod Earle; Bagas, Leon; Thomsen, Tonny B.

    2017-03-01

    Nalunaq is an orogenic, high gold grade deposit situated on the Nanortalik Peninsula, South Greenland. Mineralisation is hosted in shear zone-controlled quartz veins, located in fine- and medium-grained amphibolite. The deposit was the site of Greenland's only operating metalliferous mine until its closure in 2014, having produced 10.67 t of gold. This study uses a combination of field investigation, petrography and U/Pb zircon and titanite geochronology to define a multi-stage hydrothermal alteration system at Nalunaq. A clinopyroxene-plagioclase-garnet(-sulphide) alteration zone (CPGZ) developed in the Nanortalik Peninsula, close to regional peak metamorphism and prior to gold-quartz vein formation. The ca. 1783-1762-Ma gold-quartz veins are hosted in reactivated shear zones with a hydrothermal alteration halo of biotite-arsenopyrite-sericite-actinolite-pyrrhotite(-chlorite-plagioclase-löllingite-tourmaline-titanite), which is best developed in areas of exceptionally high gold grades. Aplite dykes dated to ca. 1762 Ma cross-cut the gold-quartz veins, providing a minimum age for mineralisation. A hydrothermal calcite-titanite alteration assemblage is dated to ca. 1766 Ma; however, this alteration is highly isolated, and as a result, its field relationships are poorly constrained. The hydrothermal alteration and mineralisation is cut by several generations of ca. 1745-Ma biotite granodiorite accompanied by brittle deformation. A ca. 1745-Ma lower greenschist facies hydrothermal epidote-calcite-zoisite alteration assemblage with numerous accessory minerals forms halos surrounding the late-stage fractures. The contrasting hydrothermal alteration styles at Nalunaq indicate a complex history of exhumation from amphibolite facies conditions to lower greenschist facies conditions in an orogenic belt which resembles modern Phanerozoic orogens.

  20. A Palaeoproterozoic multi-stage hydrothermal alteration system at Nalunaq gold deposit, South Greenland

    Science.gov (United States)

    Bell, Robin-Marie; Kolb, Jochen; Waight, Tod Earle; Bagas, Leon; Thomsen, Tonny B.

    2016-07-01

    Nalunaq is an orogenic, high gold grade deposit situated on the Nanortalik Peninsula, South Greenland. Mineralisation is hosted in shear zone-controlled quartz veins, located in fine- and medium-grained amphibolite. The deposit was the site of Greenland's only operating metalliferous mine until its closure in 2014, having produced 10.67 t of gold. This study uses a combination of field investigation, petrography and U/Pb zircon and titanite geochronology to define a multi-stage hydrothermal alteration system at Nalunaq. A clinopyroxene-plagioclase-garnet(-sulphide) alteration zone (CPGZ) developed in the Nanortalik Peninsula, close to regional peak metamorphism and prior to gold-quartz vein formation. The ca. 1783-1762-Ma gold-quartz veins are hosted in reactivated shear zones with a hydrothermal alteration halo of biotite-arsenopyrite-sericite-actinolite-pyrrhotite(-chlorite-plagioclase-löllingite-tourmaline-titanite), which is best developed in areas of exceptionally high gold grades. Aplite dykes dated to ca. 1762 Ma cross-cut the gold-quartz veins, providing a minimum age for mineralisation. A hydrothermal calcite-titanite alteration assemblage is dated to ca. 1766 Ma; however, this alteration is highly isolated, and as a result, its field relationships are poorly constrained. The hydrothermal alteration and mineralisation is cut by several generations of ca. 1745-Ma biotite granodiorite accompanied by brittle deformation. A ca. 1745-Ma lower greenschist facies hydrothermal epidote-calcite-zoisite alteration assemblage with numerous accessory minerals forms halos surrounding the late-stage fractures. The contrasting hydrothermal alteration styles at Nalunaq indicate a complex history of exhumation from amphibolite facies conditions to lower greenschist facies conditions in an orogenic belt which resembles modern Phanerozoic orogens.

  1. Continuous production of poly([R]-3-hydroxybutyrate) by Cupriavidus necator in a multistage bioreactor cascade.

    Science.gov (United States)

    Atlić, Aid; Koller, Martin; Scherzer, Dietrich; Kutschera, Christoph; Grillo-Fernandes, Elizabeth; Horvat, Predrag; Chiellini, Emo; Braunegg, Gerhart

    2011-07-01

    Poly(hydroxyalkanoates) (PHAs) constitute biodegradable polyesters and are considered among the most promising candidates to replace common petrochemical plastics in various applications. To date, all commercial processes for PHA production employ microbial discontinuous fed-batch fermentations. These processes feature drawbacks such as varying product quality and the inevitable periods of downtime for preparation and post-treatment of the bioreactor equipment. An unprecedented approach to PHA production was chosen in the presented work using a multistage system consisting of five continuous stirred tank reactors in series (5-SCR), which can be considered as a process engineering substitute of a continuous tubular plug flow reactor. The first stage of the reactor cascade is the site of balanced bacterial growth; thereafter, the fermentation broth is continuously fed from the first into the subsequent reactors, where PHA accumulation takes place under nitrogen-limiting conditions. Cupriavidus necator was used as production strain. The focus of the experimental work was devoted to the development of a PHA production process characterized by high productivity and high intracellular polymer content. The results of the experimental work with the reactor cascade demonstrated its potential in terms of volumetric and specific productivity (1.85 g L⁻¹ h⁻¹ and 0.100 g g⁻¹ h⁻¹, respectively), polymer content (77%, w/w) and polymer properties (M (w) = 665 kg/mol, PDI = 2.6). Thus, implementing the technology for 5-SCR production of PHB results in an economically viable process. The study compares the outcome of the work with literature data from continuous two-stage PHA production and industrial PHA production in fed-batch mode.

  2. Alcohol consumption and metabolic syndrome among Shanghai adults: A randomized multistage stratified cluster sampling investigation

    Institute of Scientific and Technical Information of China (English)

    Jian-Gao Fan; Xiao-Bu Cai; Lui Li; Xing-Jian Li; Fei Dai; Jun Zhu

    2008-01-01

    AIM: To examine the relations of alcohol consumption to the prevalence of metabolic syndrome in Shanghai adults.METHODS: We performed a cross-sectional analysis of data from the randomized multistage stratified cluster sampling of Shanghai adults, who were evaluated for alcohol consumption and each component of metabolic syndrome, using the adapted U.S. National Cholesterol Education Program criteria. Current alcohol consumption was defined as more than once of alcohol drinking per month.RESULTS: The study population consisted of 3953participants (1524 men) with a mean age of 54.3 ± 12.1years. Among them, 448 subjects (11.3%) were current alcohol drinkers, including 405 males and 43 females.After adjustment for age and sex, the prevalence of current alcohol drinking and metabolic syndrome in the general population of Shanghai was 13.0% and 15.3%,respectively. Compared with nondrinkers, the prevalence of hypertriglyceridemia and hypertension was higher while the prevalence of abdominal obesity, low serum high-density-lipoprotein cholesterol (HDL-C) and diabetes mellitus was lower in subjects who consumed alcohol twice or more per month, with a trend toward reducing the prevalence of metabolic syndrome. Among the current alcohol drinkers, systolic blood pressure, HDL-C, fasting plasma glucose, and prevalence of hypertriglyceridemia tended to increase with increased alcohol consumption.However, Iow-density-lipoprotein cholesterol concentration,prevalence of abdominal obesity, low serum HDL-C andmetabolic syndrome showed the tendency to decrease.Moreover, these statistically significant differences were independent of gender and age.CONCLUSION: Current alcohol consumption is associatedwith a lower prevalence of metabolic syndrome irrespe-ctive of alcohol intake (g/d), and has a favorable influence on HDL-C, waist circumference, and possible diabetes mellitus. However, alcohol intake increases the likelihoodof hypertension, hypertriglyceridemia and hyperglycemia

  3. Multistage Fatigue Modeling of Cast A356-T6 and A380-F Aluminum Alloys

    Science.gov (United States)

    Xue, Y.; Burton, C. L.; Horstemeyer, M. F.; McDowell, D. L.; Berry, J. T.

    2007-08-01

    This article presents a microstructure-based multistage fatigue (MSF) model extended from the model developed by McDowell et al.[1,2] to an A380-F aluminum alloy to consider microstructure-property relations of descending order, signifying deleterious effects of defects/discontinuities: (1) pores or oxides greater than 100 μm, (2) pores or oxides greater than 50 μm near the free surface, (3) a high porosity region with an area greater than 200 μm, and (4) oxide film of an area greater than 10,000 μm2. These microconstituents, inclusions, or discontinuities represent different casting features that may dominate fatigue life at stages of fatigue damage evolutions. The incubation life is estimated using a modified Coffin Mansion law at the microscale based on the microplasticity at the discontinuity. The microstructurally small crack (MSC) and physically small crack (PSC) growth was modeled using the crack tip displacement as the driving force, which is affected by the porosity and dendrite cell size (DCS). When the fatigue damage evolves to several DCSs, cracks behave as long cracks with growth subject to the effective stress intensity factor in linear elastic fracture mechanics. Based on an understanding of the microstructures of A380-F and A356-T6 aluminum alloys, an engineering treatment of the MSF model was introduced for A380-F aluminum alloys by tailoring a few model parameters based on the mechanical properties of the alloy. The MSF model is used to predict the upper and lower bounds of the experimental fatigue strain life and stress life of the two cast aluminum alloys.

  4. Aqueous Processing for Printed Organic Electronics: Conjugated Polymers with Multistage Cleavable Side Chains.

    Science.gov (United States)

    Schmatz, Brian; Yuan, Zhibo; Lang, Augustus W; Hernandez, Jeff L; Reichmanis, Elsa; Reynolds, John R

    2017-09-27

    The ability to process conjugated polymers via aqueous solution is highly advantageous for reducing the costs and environmental hazards of large scale roll-to-roll processing of organic electronics. However, maintaining competitive electronic properties while achieving aqueous solubility is difficult for several reasons: (1) Materials with polar functional groups that provide aqueous solubility can be difficult to purify and characterize, (2) many traditional coupling and polymerization reactions cannot be performed in aqueous solution, and (3) ionic groups, though useful for obtaining aqueous solubility, can lead to a loss of solid-state order, as well as a screening of any applied bias. As an alternative, we report a multistage cleavable side chain method that combines desirable aqueous processing attributes without sacrificing semiconducting capabilities. Through the attachment of cleavable side chains, conjugated polymers have for the first time been synthesized, characterized, and purified in organic solvents, converted to a water-soluble form for aqueous processing, and brought through a final treatment to cleave the polymer side chains and leave behind the desired electronic material as a solvent-resistant film. Specifically, we demonstrate an organic soluble polythiophene that is converted to an aqueous soluble polyelectrolyte via hydrolysis. After blade coating from an aqueous solution, UV irradiation is used to cleave the polymer's side chains, resulting in a solvent-resistant, electroactive polymer thin film. In application, this process results in aqueous printed materials with utility for solid-state charge transport in organic field effect transistors (OFETs), along with red to colorless electrochromism in ionic media for color changing displays, demonstrating its potential as a universal method for aqueous printing in organic electronics.

  5. Three Dimensional Human Neuro-Spheroid Model of Alzheimer’s Disease Based on Differentiated Induced Pluripotent Stem Cells

    Science.gov (United States)

    Lee, Han-Kyu; Velazquez Sanchez, Clara; Chen, Mei; Morin, Peter J.; Wells, John M.; Hanlon, Eugene B.

    2016-01-01

    The testing of candidate drugs to slow progression of Alzheimer’s disease (AD) requires clinical trials that are lengthy and expensive. Efforts to model the biochemical milieu of the AD brain may be greatly facilitated by combining two cutting edge technologies to generate three-dimensional (3D) human neuro-spheroid from induced pluripotent stem cells (iPSC) derived from AD subjects. We created iPSC from blood cells of five AD patients and differentiated them into 3D human neuronal culture. We characterized neuronal markers of our 3D neurons by immunocytochemical staining to validate the differentiation status. To block the generation of pathologic amyloid β peptides (Aβ), the 3D-differentiated AD neurons were treated with inhibitors targeting β-secretase (BACE1) and γ-secretases. As predicted, both BACE1 and γ-secretase inhibitors dramatically decreased Aβ generation in iPSC-derived neural cells derived from all five AD patients, under standard two-dimensional (2D) differentiation conditions. However, BACE1 and γ-secretase inhibitors showed less potency in decreasing Aβ levels in neural cells differentiated under 3D culture conditions. Interestingly, in a single subject AD1, we found that BACE1 inhibitor treatment was not able to significantly reduce Aβ42 levels. To investigate underlying molecular mechanisms, we performed proteomic analysis of 3D AD human neuronal cultures including AD1. Proteomic analysis revealed specific reduction of several proteins that might contribute to a poor inhibition of BACE1 in subject AD1. To our knowledge, this is the first iPSC-differentiated 3D neuro-spheroid model derived from AD patients’ blood. Our results demonstrate that our 3D human neuro-spheroid model can be a physiologically relevant and valid model for testing efficacy of AD drug. PMID:27684569

  6. Two differential flows in a bioreactor promoted platelet generation from human pluripotent stem cell-derived megakaryocytes.

    Science.gov (United States)

    Nakagawa, Yosuke; Nakamura, Sou; Nakajima, Masahiro; Endo, Hiroshi; Dohda, Takeaki; Takayama, Naoya; Nakauchi, Hiromitsu; Arai, Fumihito; Fukuda, Toshio; Eto, Koji

    2013-08-01

    Induced pluripotent stem cell (iPSC) technology enables us to investigate various potential iPSC-based therapies. Although the safety of iPSC derivation has not been completely validated, anucleate cells, such as platelets or erythrocytes, derived from iPSCs are promising targets. However, the efficiency of in vitro platelet generation from megakaryocytes (MKs) under static culture conditions is lower than is seen in vivo. In this study, we demonstrate the proof of concept by a two-dimensional flow culture system that enabled us to increase platelet yield from human embryonic stem cell or iPSC-derived MKs using a biomimetic artificial blood vessel system. The bioreactor was composed of biodegradable scaffolds with ordered arrays of pores made to mimic in vivo bone marrow through salt leaching. Within the system, two flows in different directions in which the angle between the directions of flow is 60 degrees but not 90 degrees contributed to suitable pressure and shear stress applied to MKs to promote platelet generation. Generated platelets derived from human embryonic stem cells or human induced pluripotent stem cells through the bioreactor with a 60-degree angle revealed intact integrin αIIbβ3 activation after agonist stimulation. Collectively, our findings indicate that two flows in different directions of two-dimensional flow culture may be a feasible system for in vitro generation of platelets from pluripotent stem cells (i.e., iPSC-derived MKs) in numbers sufficient for transfusion therapy.

  7. Determination of rational design parameters of a multi-stage solar water desalination still using transient mathematical modelling

    Energy Technology Data Exchange (ETDEWEB)

    Shatat, M.I.M.; Mahkamov, K. [School of Engineering, Durham University, South Road, Durham, DH1 3LE (United Kingdom)

    2010-01-15

    The paper describes the experimental investigations of the performance of a multi-stage water desalination still connected to a heat pipe evacuated tube solar collector with aperture area of 1.7 m{sup 2}. The multi-stage solar still water desalination system was designed to recover latent heat from evaporation and condensation processes in four stages. The variation in the solar radiation during a typical mid-summer day in the Middle East region was simulated on the test rig using an array of 110 halogen floodlights covering the area of the collector. The results of tests demonstrate that the system produces about 9 kg of fresh water per day and has a solar collector efficiency of about 68%. However, the overall efficiency of the laboratory test rig at this stage of the investigations was found to be at the level of 33% due to excessive heat losses in the system. The analysis of the distilled water showed that its quality was within the World Health Organization guidelines. The still's operation was numerically simulated by employing a mathematical model based on a system of ordinary energy and mass conservation differential equations written for each stage of the still. A computer program was developed for transient simulations of the evaporation and condensation processes inside the multi-stage still. Experimental results obtained and theoretical predictions were found to be in good agreement. The results on the determination of rational design dimensions and number of stages of the still for a given aperture of the solar collector are also presented in this work. (author)

  8. Aerobic biodegradation of a sulfonated phenylazonaphthol dye by a bacterial community immobilized in a multistage packed-bed BAC reactor.

    Science.gov (United States)

    Ruiz-Arias, Alfredo; Juárez-Ramírez, Cleotilde; de los Cobos-Vasconcelos, Daniel; Ruiz-Ordaz, Nora; Salmerón-Alcocer, Angélica; Ahuatzi-Chacón, Deifilia; Galíndez-Mayer, Juvencio

    2010-11-01

    A microbial community able to aerobically degrade the azo dye Acid Orange 7 was selected from riparian or lacustrine sediments collected at sites receiving textile wastewaters. Three bacterial strains, pertaining to the genera Pseudomonas, Arthrobacter, and Rhizobium, constitute the selected community. The biodegradation of AO7 was carried out in batch-suspended cell culture and in a continuously operated multistage packed-bed BAC reactor. The rapid decolorization observed in batch culture, joined to a delay of about 24 h in COD removal and cell growth, suggests that enzymes involved in biodegradation of the aromatic amines generated after AO7 azo-bond cleavage (1-amino-2-naphthol [1-A2N] and 4-aminobenzenesulfonic acid [4-ABS]), are inducible in this microbial consortium. After this presumptive induction period, the accumulated byproducts, measured through COD, were partially metabolized and transformed in cell mass. At all azo dye loading rates used, complete removal of AO7 and 1-A2N was obtained in the multistage packed-bed BAC reactor (PBR).; however, the overall COD (eta ( COD )) and 4-ABS (eta ( ABS )) removal efficiencies obtained in steady state continuous culture were about 90%. Considering the toxicity of 1-A2N, its complete removal has particular relevance. In the first stages of the packed-bed BAC reactor (Fig. 4a-c), major removal was observed. In the last stage, only a slight removal of COD and 4-ABS was obtained. Comparing to several reported studies, the continuously operated multistage packed-bed BAC reactor showed similar or superior results. In addition, the operation of large-packed-bed BAC reactors could be improved by using several shallow BAC bed stages, because the pressure drop caused by bed compaction of a support material constituted by small and fragile particles can be reduced.

  9. SYNTHESIS OF THICK GALLIUM NITRIDE LAYERS BY METHOD OF MULTI-STAGE GROWTH ON SUBSTRATES WITH COLUMN STRUCTURE

    Directory of Open Access Journals (Sweden)

    Marina G. Mynbaeva

    2016-11-01

    Full Text Available Subject of Research.The paper deals with processes of formation and transformation of defects during multi-stage growth of thick gallium nitride layers with hydride vapor phase epitaxy on GaN/Al2O3 substrates with buried column pattern formed with the use of metal-organic vapor phase epitaxy. Methods. The growth of initial GaN layers was performed with the use of metal-organic vapor phase epitaxy. On the surface of the initial layers columns with the height of 800 nm were generated by means of ion etching. These columns were overgrown with 3-4 µm-thick GaN layers. On thus formed substrate multi-stage growth of GaN layers was performed with the use of hydride vapor-phase epitaxy. The total thickness of GaN layers was 100-1500 µm. The grown layers were studied by optical and electron microscopy and Raman spectroscopy. Main Results. Density of threading dislocations in the layers grown by hydride vapor-phase epitaxy was (3-6·107 cm-2, that was one order of magnitude lower than in the used substrate, and two to three orders lower than dislocation density in typical GaN layers grown on commercial sapphire substrates. Raman spectroscopy data were indicative of low level of mechanical stress in the layers and their high structural uniformity. It was established that under multi-stage growth conditions, non-catastrophic cracks (those that do not cause sample destruction are able to transform into macropores and appear to be an important structural element, serving to stress relaxation in the bulk of thick gallium nitride layers grown on foreign substrates. Practical Relevance. The results of the study can be used in the development of III-nitride heterostructures for optoelectronics and high-power and high-frequency microelectronics.

  10. A multi-stage 3-D stress field modelling approach exemplified in the Bavarian Molasse Basin

    Science.gov (United States)

    Ziegler, Moritz O.; Heidbach, Oliver; Reinecker, John; Przybycin, Anna M.; Scheck-Wenderoth, Magdalena

    2016-09-01

    The knowledge of the contemporary in situ stress state is a key issue for safe and sustainable subsurface engineering. However, information on the orientation and magnitudes of the stress state is limited and often not available for the areas of interest. Therefore 3-D geomechanical-numerical modelling is used to estimate the in situ stress state and the distance of faults from failure for application in subsurface engineering. The main challenge in this approach is to bridge the gap in scale between the widely scattered data used for calibration of the model and the high resolution in the target area required for the application. We present a multi-stage 3-D geomechanical-numerical approach which provides a state-of-the-art model of the stress field for a reservoir-scale area from widely scattered data records. Therefore, we first use a large-scale regional model which is calibrated by available stress data and provides the full 3-D stress tensor at discrete points in the entire model volume. The modelled stress state is used subsequently for the calibration of a smaller-scale model located within the large-scale model in an area without any observed stress data records. We exemplify this approach with two-stages for the area around Munich in the German Molasse Basin. As an example of application, we estimate the scalar values for slip tendency and fracture potential from the model results as measures for the criticality of fault reactivation in the reservoir-scale model. The modelling results show that variations due to uncertainties in the input data are mainly introduced by the uncertain material properties and missing SHmax magnitude estimates needed for a more reliable model calibration. This leads to the conclusion that at this stage the model's reliability depends only on the amount and quality of available stress information rather than on the modelling technique itself or on local details of the model geometry. Any improvements in modelling and increases

  11. Overall Traveling-Wave-Tube Efficiency Improved By Optimized Multistage Depressed Collector Design

    Science.gov (United States)

    Vaden, Karl R.

    2002-01-01

    Depressed Collector Design The microwave traveling wave tube (TWT) is used widely for space communications and high-power airborne transmitting sources. One of the most important features in designing a TWT is overall efficiency. Yet, overall TWT efficiency is strongly dependent on the efficiency of the electron beam collector, particularly for high values of collector efficiency. For these reasons, the NASA Glenn Research Center developed an optimization algorithm based on simulated annealing to quickly design highly efficient multistage depressed collectors (MDC's). Simulated annealing is a strategy for solving highly nonlinear combinatorial optimization problems. Its major advantage over other methods is its ability to avoid becoming trapped in local minima. Simulated annealing is based on an analogy to statistical thermodynamics, specifically the physical process of annealing: heating a material to a temperature that permits many atomic rearrangements and then cooling it carefully and slowly, until it freezes into a strong, minimum-energy crystalline structure. This minimum energy crystal corresponds to the optimal solution of a mathematical optimization problem. The TWT used as a baseline for optimization was the 32-GHz, 10-W, helical TWT developed for the Cassini mission to Saturn. The method of collector analysis and design used was a 2-1/2-dimensional computational procedure that employs two types of codes, a large signal analysis code and an electron trajectory code. The large signal analysis code produces the spatial, energetic, and temporal distributions of the spent beam entering the MDC. An electron trajectory code uses the resultant data to perform the actual collector analysis. The MDC was optimized for maximum MDC efficiency and minimum final kinetic energy of all collected electrons (to reduce heat transfer). The preceding figure shows the geometric and electrical configuration of an optimized collector with an efficiency of 93.8 percent. The

  12. Effects of Shrouded Stator Cavity Flows on Multistage Axial Compressor Aerodynamic Performance

    Science.gov (United States)

    Wellborn, Steven R.; Okiishi, Theodore H.

    1996-01-01

    Experiments were performed on a low-speed multistage axial-flow compressor to assess the effects of shrouded stator cavity flows on aerodynamic performance. Five configurations, which involved changes in seal-tooth leakage rates and/or elimination of the shrouded stator cavities, were tested. Data collected enabled differences in overall individual stage and the third stage blade element performance parameters to be compared. The results show conclusively that seal-tooth leakage ran have a large impact on compressor aerodynamic performance while the presence of the shrouded stator cavities alone seemed to have little influence. Overall performance data revealed that for every 1% increase in the seal-tooth clearance to blade-height ratio the pressure rise dropped up to 3% while efficiency was reduced by 1 to 1.5 points. These observed efficiency penalty slopes are comparable to those commonly reported for rotor and cantilevered stator tip clearance variations. Therefore, it appears that in order to correctly predict overall performance it is equally important to account for the effects of seal-tooth leakage as it is to include the influence of tip clearance flows. Third stage blade element performance data suggested that the performance degradation observed when leakage was increased was brought about in two distinct ways. First, increasing seal-tooth leakage directly spoiled the near hub performance of the stator row in which leakage occurred. Second, the altered stator exit now conditions caused by increased leakage impaired the performance of the next downstream stage by decreasing the work input of the downstream rotor and increasing total pressure loss of the downstream stator. These trends caused downstream stages to progressively perform worse. Other measurements were acquired to determine spatial and temporal flow field variations within the up-and-downstream shrouded stator cavities. Flow within the cavities involved low momentum fluid traveling primarily

  13. Incorporation of electrochemical advanced oxidation processes in a multistage treatment system for sanitary landfill leachate.

    Science.gov (United States)

    Moreira, Francisca C; Soler, J; Fonseca, Amélia; Saraiva, Isabel; Boaventura, Rui A R; Brillas, Enric; Vilar, Vítor J P

    2015-09-15

    The current study has proved the technical feasibility of including electrochemical advanced oxidation processes (EAOPs) in a multistage strategy for the remediation of a sanitary landfill leachate that embraced: (i) first biological treatment to remove the biodegradable organic fraction, oxidize ammonium and reduce alkalinity, (ii) coagulation of the bio-treated leachate to precipitate humic acids and particles, followed by separation of the clarified effluent, and (iii) oxidation of the resulting effluent by an EAOP to degrade the recalcitrant organic matter and increase its biodegradability so that a second biological process for removal of biodegradable organics and nitrogen content could be applied. The influence of current density on an UVA photoelectro-Fenton (PEF) process was firstly assessed. The oxidation ability of various EAOPs such as electro-Fenton (EF) with two distinct initial total dissolved iron concentrations ([TDI]0), PEF and solar PEF (SPEF) was further evaluated and these processes were compared with their analogous chemical ones. A detailed assessment of the two first treatment stages was made and the biodegradability enhancement during the SPEF process was determined by a Zahn-Wellens test to define the ideal organics oxidation state to stop the EAOP and apply the second biological treatment. The best current density was 200 mA cm(-2) for a PEF process using a BDD anode, [TDI]0 of 60 mg L(-1), pH 2.8 and 20 °C. The relative oxidation ability of EAOPs increased in the order EF with 12 mg [TDI]0 L(-1) < EF with 60 mg [TDI]0 L(-1) < PEF with 60 mg [TDI]0 L(-1) ≤ SPEF with 60 mg [TDI]0 L(-1), using the abovementioned conditions. While EF process was much superior to the Fenton one, the superiority of PEF over photo-Fenton was less evident and SPEF attained similar degradation to solar photo-Fenton. To provide a final dissolved organic carbon (DOC) of 163 mg L(-1) to fulfill the discharge limits into the environment after

  14. Multistage Carcinogenesis Modelling of Low and Protracted Radiation Exposure for Risk Assessment

    Science.gov (United States)

    Brugmans, M. J. P.; Bijwaard, H.

    Exposure to cosmic radiation in space poses an increased risk for radiation-induced cancer later in life. Modelling is essential to quantify these excess risks from low and protracted exposures to a mixture of radiation types, since they cannot be determined directly in epidemiological studies. Multistage carcinogenesis models provide a mechanistic basis for the extrapolation of epidemiological data to the regime that is relevant for radiation protection. In recent years, we have exploited the well-known two-mutation carcinogenesis model to bridge the gap between radiobiology and epidemiology. We have fitted this model to a number of animal and epidemiological data sets, using dose-response relationships for the mutational steps that are well established in cellular radiobiology. The methodology and implications for radiation risks are illustrated with analyses of two radiation-induced tumours: bone cancer from internal (high-LET and low-LET) emitters and lung cancer after radon exposure. For the risks of bone-seeking radionuclides (Ra-226, Sr-90, Pu-239), model fits to beagle data show that the dose-effect relationship for bone cancer at low intakes is linear-quadratic. This is due to a combination of equally strong linear dose-effects in the two subsequent mutational steps in the model. This supra-linear dose-effect relationship is also found in a model analysis of bone cancer in radium dial painters. This implies that at low intakes the risks from bone seekers are significantly lower than estimated from a linear extrapolation from high doses. Model analyses of radon-exposed rats and uranium miners show that lung-cancer induction is dominated by a linear radiation effect in the first mutational step. For two miner cohorts with significantly different lung cancer baselines a uniform description of the effect of radon is obtained in a joint analysis. This demonstrates the possibility to model risk transfer across populations. In addition to biologically based risk

  15. A multistage chronobiologic intervention for the treatment of depression: a pilot study.

    Science.gov (United States)

    Moscovici, Lucian; Kotler, Moshe

    2009-08-01

    Most antidepressant medications in current use have several disadvantages: a delayed therapeutic effect, side effects, stigmatization and concerns about safety for the developing fetus during pregnancy. Several chronobiologic techniques which are free of these disadvantages were proposed as an alternative. The current article reports the design and the initial outcome results of a new chronobiologic multistage intervention (CMI) that is comprised of the following techniques: (i) partial sleep deprivation during the second half of the night (wake therapy--WT), (ii) medium (green) wavelength light in combination with dawn simulation (DS), (iii) bright light therapy (BLT), and (iv) sleep phase advance (SPA). The study was conducted as a set of 12 single-case designs with moderate-to-severe depressive volunteering patients. Depression, anxiety and tension measurements were taken on a daily basis beginning with a baseline measurement (T0), followed by a set of four consecutive morning measurements during the therapeutic intervention (T1-T4),and with a final measurement carried out at the end of 4 weeks of follow-up (T5). A clinically significant rapid improvement of the depressive symptoms was demonstrated and maintained for at least 4 weeks after the end of the intervention. No dropouts or compliance difficulties were observed. Patient satisfaction was high, and other than having to sleep for four nights at the Research and Development Unit, participants were not inconvenienced by the nature of the therapeutic design. Sleepiness in the late afternoon hours was reported by several of the participants, but did not reach a level that interfered with their ability to function. Levels of tension did not show a consistent improvement along the intervention procedure and were not maintained in follow-up. There was some unexpected improvement in the level of anxiety that persisted at follow-up. This latter finding requires further validation by additional studies. These

  16. Utilization of parallel processing in solving the inviscid form of the average-passage equation system for multistage turbomachinery

    Science.gov (United States)

    Mulac, Richard A.; Celestina, Mark L.; Adamczyk, John J.; Misegades, Kent P.; Dawson, Jef M.

    1987-01-01

    A procedure is outlined which utilizes parallel processing to solve the inviscid form of the average-passage equation system for multistage turbomachinery along with a description of its implementation in a FORTRAN computer code, MSTAGE. A scheme to reduce the central memory requirements of the program is also detailed. Both the multitasking and I/O routines referred to are specific to the Cray X-MP line of computers and its associated SSD (Solid-State Disk). Results are presented for a simulation of a two-stage rocket engine fuel pump turbine.

  17. The utilization of parallel processing in solving the inviscid form of the average-passage equation system for multistage turbomachinery

    Science.gov (United States)

    Mulac, Richard A.; Celestina, Mark L.; Adamczyk, John J.; Misegades, Kent P.; Dawson, Jef M.

    1987-01-01

    A procedure is outlined which utilizes parallel processing to solve the inviscid form of the average-passage equation system for multistage turbomachinery along with a description of its implementation in a FORTRAN computer code, MSTAGE. A scheme to reduce the central memory requirements of the program is also detailed. Both the multitasking and I/O routines referred to in this paper are specific to the Cray X-MP line of computers and its associated SSD (Solid-state Storage Device). Results are presented for a simulation of a two-stage rocket engine fuel pump turbine.

  18. Multi-stage pulse tube cryocooler with acoustic impedance constructed to reduce transient cool down time and thermal loss

    Science.gov (United States)

    Gedeon, David R. (Inventor); Wilson, Kyle B. (Inventor)

    2008-01-01

    The cool down time for a multi-stage, pulse tube cryocooler is reduced by configuring at least a portion of the acoustic impedance of a selected stage, higher than the first stage, so that it surrounds the cold head of the selected stage. The surrounding acoustic impedance of the selected stage is mounted in thermally conductive connection to the warm region of the selected stage for cooling the acoustic impedance and is fabricated of a high thermal diffusivity, low thermal radiation emissivity material, preferably aluminum.

  19. Applications of the Magnetocaloric Effect in Single-Stage, Multi-Stage and Continuous Adiabatic Demagnetization Refrigerators

    Science.gov (United States)

    Shirron, Peter J.

    2014-01-01

    Adiabatic demagnetization refrigerators (ADR), based on the magnetocaloric effect, are solid-state coolers that were the first to achieve cooling well into the sub-kelvin regime. Although supplanted by more powerful dilution refrigerators in the 1960s, ADRs have experienced a revival due to the needs of the space community for cooling astronomical instruments and detectors to temperatures below 100 mK. The earliest of these were single-stage refrigerators using superfluid helium as a heat sink. Their modest cooling power (magnetocaloric effect and its application in single-stage systems, and then describing the challenges and capabilities of multi-stage and continuous ADRs.

  20. Multi-stage IT project evaluation: The flexibility value obtained by implementing and resolving Berk, Green and Naik (2004) model

    Science.gov (United States)

    Abid, Fathi; Guermazi, Dorra

    2009-11-01

    In this paper, we evaluate a multi-stage information technology investment project, by implementing and resolving Berk, Green and Naik's (2004) model, which takes into account specific features of IT projects and considers the real option to suspend investment at each stage. We present a particular case of the model where the project value is the solution of an optimal control problem with a single state variable. In this case, the model is more intuitive and tractable. The case study confirms the practical potential of the model and highlights the importance of the real-option approach compared to classical discounted cash flow techniques in the valuation of IT projects.

  1. Approximate Solutions of Delay Differential Equations with Constant and Variable Coefficients by the Enhanced Multistage Homotopy Perturbation Method

    Directory of Open Access Journals (Sweden)

    D. Olvera

    2015-01-01

    Full Text Available We expand the application of the enhanced multistage homotopy perturbation method (EMHPM to solve delay differential equations (DDEs with constant and variable coefficients. This EMHPM is based on a sequence of subintervals that provide approximate solutions that require less CPU time than those computed from the dde23 MATLAB numerical integration algorithm solutions. To address the accuracy of our proposed approach, we examine the solutions of several DDEs having constant and variable coefficients, finding predictions with a good match relative to the corresponding numerical integration solutions.

  2. Human neural progenitors derived from integration-free iPSCs for SCI therapy

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2017-03-01

    Full Text Available As a potentially unlimited autologous cell source, patient induced pluripotent stem cells (iPSCs provide great capability for tissue regeneration, particularly in spinal cord injury (SCI. However, despite significant progress made in translation of iPSC-derived neural progenitor cells (NPCs to clinical settings, a few hurdles remain. Among them, non-invasive approach to obtain source cells in a timely manner, safer integration-free delivery of reprogramming factors, and purification of NPCs before transplantation are top priorities to overcome. In this study, we developed a safe and cost-effective pipeline to generate clinically relevant NPCs. We first isolated cells from patients' urine and reprogrammed them into iPSCs by non-integrating Sendai viral vectors, and carried out experiments on neural differentiation. NPCs were purified by A2B5, an antibody specifically recognizing a glycoganglioside on the cell surface of neural lineage cells, via fluorescence activated cell sorting. Upon further in vitro induction, NPCs were able to give rise to neurons, oligodendrocytes and astrocytes. To test the functionality of the A2B5+ NPCs, we grafted them into the contused mouse thoracic spinal cord. Eight weeks after transplantation, the grafted cells survived, integrated into the injured spinal cord, and differentiated into neurons and glia. Our specific focus on cell source, reprogramming, differentiation and purification method purposely addresses timing and safety issues of transplantation to SCI models. It is our belief that this work takes one step closer on using human iPSC derivatives to SCI clinical settings.

  3. Derivation, Expansion, and Motor Neuron Differentiation of Human-Induced Pluripotent Stem Cells with Non-Integrating Episomal Vectors and a Defined Xenogeneic-free Culture System.

    Science.gov (United States)

    Hu, Wentao; He, Yongpei; Xiong, Yongjie; Lu, Hong; Chen, Hong; Hou, Limin; Qiu, Zhandong; Fang, Yu; Zhang, Suming

    2016-04-01

    Induced pluripotent stem cells (iPSCs) generated from patient-derived somatic cells provides the opportunity for model development in order to study patient-specific disease states with the potential for drug discovery. However, use of lentivirus and exposure of iPSCs to animal-derived products limit their therapeutic utility and affect lineage differentiation and subsequent downstream functionality of iPSC derivatives. Within the context of this study, we describe a simple and practical protocol enabling the efficient reprogramming of terminally differentiated adult fibroblasts into integration-free human iPSCs (hiPSCs) using a combination of episomal plasmids with small molecules (SMs). Using this approach, there was a 10-fold increase in reprogramming efficiency over single plasmid vector-based methods. We obtained approximately 100 iPSCs colonies from 1 × 10(5) human adult dermal fibroblasts (HADFs) and achieved approximately 0.1% reprogramming efficiencies. Concurrently, we developed a highly conducive culture system using xeno-free media and human vitronectin. The resulting hiPSCs were free of DNA integration and had completely lost episomal vectors, maintained long-term self-renewal, featured a normal karyotype, expressed pluripotent stem cell markers, and possessed the capability of differentiating into components of all three germ layers in vivo. Finally, we demonstrate that the integration-free hiPSCs could be differentiated into motor neurons under xeno-free culture conditions. This induction method will promote the derivation of patient-specific integration-free and xeno-free iPSCs and improve the strategy for motor neuron derivation. Our approach provides a useful tool for human disease models, drug screen, and clinical applications.

  4. A MULTISTAGE GRADUAL NITROGENREDUCTION STRATEGY FOR INCREASED LIPID PRODUCTIVITY AND NITROGEN REMOVAL IN WASTEWATER USING Chlorella vulgaris AND Scenedesmus obliquus

    Directory of Open Access Journals (Sweden)

    J. C. Robles-Heredia

    2015-06-01

    Full Text Available AbstractChlorella vulgaris and Scenedesmus obliquuswere grown in artificial-wastewater using a new nitrogen-limitation strategy aimed at increasing lipid productivity. This strategy consisted in a multi-stage process with sequential reduction of N-NH4 concentration (from 90 to 60, 40, and 20 mg.L-1 to promote a balance between cell growth and lipid accumulation. Lipid productivity was compared against a reference process consisting of nitrogen reduction in two stages, where the nitrogen concentration was suddenly reduced from 90 mg.L-1 to three different concentrations (10, 20, and 30 mg.L-1. In the multi-stage mode, only C. vulgaris exhibited a net lipid-productivity increase. Lipid content of S. obliquus did not present a significant increase, thus decreasing lipid productivity. The highest lipid productivities were observed in the two-stage mode for both S. obliquus and C. vulgaris (194.9 and 133.5 mg.L-1.d-1, respectively, and these values are among the highest reported in the literature to date.

  5. Multi-Stage Control of Waste Heat Recovery from High Temperature Slags Based on Time Temperature Transformation Curves

    Directory of Open Access Journals (Sweden)

    Yongqi Sun

    2014-03-01

    Full Text Available This paper presents a significant method and a basic idea of waste heat recovery from high temperature slags based on Time Temperature Transformation (TTT curves. Three samples with a fixed CaO/SiO2 ratio of 1.05 and different levels of Al2O3 were designed and isothermal experiments were performed using a Single Hot Thermocouple Technique (SHTT. The TTT curves established through SHTT experiments described well the variation of slag properties during isothermal processes. In this study, we propose a multi-stage control method for waste heat recovery from high temperature slags, in which the whole temperature range from 1500 °C to 25 °C was divided into three regions, i.e., Liquid region, Crystallization region and Solid region, based on the TTT curves. Accordingly, we put forward an industrial prototype plant for the purpose of waste heat recovery and the potential of waste heat recovery was then calculated. The multi-stage control method provided not only a significant prototype, but also a basic idea to simultaneously extract high quality waste heat and obtain glassy phases on high temperature slags, which may fill the gap between slag properties and practical waste heat recovery processes.

  6. Multi area and multistage expansion-planning of electricity supply with sustainable energy development criteria: a multi objective model

    Energy Technology Data Exchange (ETDEWEB)

    Unsihuay-Vila, Clodomiro; Marangon-Lima, J.W.; Souza, A.C Zambroni de [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)], emails: clodomirounsihuayvila @gmail.com, marangon@unifei.edu.br, zambroni@unifei.edu.br; Perez-Arriaga, I.J. [Universidad Pontificia Comillas, Madrid (Spain)], email: ipa@mit.edu

    2010-07-01

    A novel multi objective, multi area and multistage model to long-term expansion-planning of integrated generation and transmission corridors incorporating sustainable energy developing is presented in this paper. The proposed MESEDES model is a multi-regional multi-objective and 'bottom-up' energy model which considers the electricity generation/transmission value-chain, i.e., power generation alternatives including renewable, nuclear and traditional thermal generation along with transmission corridors. The model decides the optimal location and timing of the electricity generation/transmission abroad the multistage planning horizon. The MESEDES model considers three objectives belonging to sustainable energy development criteria such as: a) the minimization of investments and operation costs of : power generation, transmission corridors, energy efficiency (demand side management (DSM) programs) considering CO2 capture technologies; b) minimization of Life Cycle Greenhouse Gas Emissions (LC GHG); c) maximization of the diversification of electricity generation mix. The proposed model consider aspects of the carbon abatement policy under the CDM - Clean Development Mechanism or European Union Greenhouse Gas Emission Trading Scheme. A case study is used to illustrate the proposed framework. (author)

  7. A Scenario Tree based Stochastic Programming Approach for Multi-Stage Weapon Equipment Mix Production Planning in Defense Manufacturing

    Directory of Open Access Journals (Sweden)

    Li Xuan

    2016-01-01

    Full Text Available The evolving military capability requirements (CRs must be meted continuously by the multi-stage weapon equipment mix production planning (MWEMPP. Meanwhile, the CRs possess complex uncertainties with the variant military tasks in the whole planning horizon. The mean-value deterministic programming technique is difficult to deal with the multi-period and multi-level uncertain decision-making problem in MWEMPP. Therefore, a multi-stage stochastic programming approach is proposed to solve this problem. This approach first uses the scenario tree to quantitatively describe the bi-level uncertainty of the time and quantity of the CRs, and then build the whole off-line planning alternatives assembles for each possible scenario, at last the optimal planning alternative is selected on-line to flexibly encounter the real scenario in each period. A case is studied to validate the proposed approach. The results confirm that the proposed approach can better hedge against each scenario of the CRs than the traditional mean-value deterministic technique.

  8. Flow Field Measurement in Multi-stage Axial Compressor Stator by Using Multi-hole Pneumatic Probes

    Science.gov (United States)

    Zhiqiang, Wang; Bo, Lu; Chenkai, Zhang; Jun, Hu

    2017-04-01

    In order to realize the stator's internal flow field measurement of the multi-stage axial compressor, many different lengths of L-type five-hole probes and one four-hole probe have been designed. The detailed 3D (three-dimensional) flow fields in the stator blade passage of original and modified large scale compressors have been measured with the probes traversed by a probe traverse mechanism. The objective of the study is to assess the measurement method of adopting multi-hole pneumatic probes to achieve the flow field of stator vane passage. Results clearly demonstrate the flow field characteristics of stator blade passage in original and modified compressors. Furthermore, the reliability of adopted multi-hole pneumatic probes is validated. Therefore, it is proved that the probe traverse mechanism drives the L-type five-hole probe or other probe method can be applied to internal flow field measurements for the stator of large scale multi-stage compressors.

  9. Optimum design of multi-layer K-edge filter and multi-stage detectors for triple energy bone densitometer

    Science.gov (United States)

    Mazoochi, Alireza; Rahmani, Faezeh; Abbasi Davani, Fereydoun; Ghaderi, Ruhollah

    2014-03-01

    Dual X-ray bone densitometry may cause some errors in diagnosis due to heterogeneous distribution of adipose tissue. It is necessary to develop a more accurate technique to consider the effects of fat. In this research, a triple energy X-ray method has been introduced and conceptual design of a system consisting of 160 kV X-ray tube, multi-layer K-edge filter and multi-stage detector has been presented. Design calculations have been performed using MCNP4C Monte Carlo code to select the type of filters and detectors with the best thicknesses for better distinguishing materials. The energy peaks (37 keV, 50 keV and 105 keV) can be separated optimally with a multi-layer filter composed of barium (170 μm) and gadolinium (100 μm) as the first and second layers, respectively which are coated on a 1 mm aluminum plate placed between the source and tissue. The transmitted photons have been counted by a multi-stage linear array of detectors consisting of ZnSe(Te) and CsI(Tl) with 400 μm and 5 mm thicknesses, respectively. Monte Carlo simulations show that the triple energy X-ray technique has better accuracy than that of the standard dual energy X-ray technique.

  10. Multistage continuous cultivation of blue-green alga Spirulina maxima in the flat tank photobioreactors with recycle

    Energy Technology Data Exchange (ETDEWEB)

    Samson, R.; Leduy, A.

    1985-02-01

    Spirulina maxima was continuously cultivated in four 64-liter flat tank photobioreactors in cascade, under continuous 30 Klx fluorescent light and nonaseptic condition, in an industrial grade synthetic medium which bubbled with atmospheric air. The increase in the number of stages resulted in the higher biomass concentration and allowed operation with a dilution rate D higher than the alga specific growth rate. However, multistage operation does not permit a significant increase in productivity. The recycling of the all culture medium with biomass increased the net productivity of the first two stages of the multistage system. The flat tank design offered great advantages over other geometrical configurations by occupying less space for indoor cultivation, minimizing the water loss by evaporation, and permitting a greater flexibility in construction, installation, and operation. This system was operating continuously for two years in our laboratory for indoor mass production of S. maxima biomass. The flat tank configuration gave the highest areal productivity Pa = 60.5 g/squared m.d and highest volumetric productivity Pv = 1.17 g/L.d when operated as a single stage continuous cultivation with high solid recycle. These values are the highest ever reported for any indoor or outdoor mass production system for S. maxima. 26 references.

  11. Research on Three-Dimensional Unsteady Turbulent Flow in Multistage Centrifugal Pump and Performance Prediction Based on CFD

    Directory of Open Access Journals (Sweden)

    Zhi-jian Wang

    2013-01-01

    Full Text Available The three-dimensional flow physical model of any stage of the 20BZ4 multistage centrifugal pump is built which includes inlet region, impeller flow region, guide-vane flow region and exit region. The three-dimensional unsteady turbulent flow numerical model is created based on Navier-Stoke solver and standard k-ε turbulent equations. The method of multireference frame (MRF and SIMPLE algorithm are used to simulate the flow in multistage centrifugal pump based on FLUENT software. The distributions of relative velocity, absolute velocity, static pressure, and total pressure in guide vanes and impellers under design condition are analyzed. The simulation results show that the flow in impeller is mostly uniform, without eddy, backflow, and separation flow, and jet-wake phenomenon appears only along individual blades. There is secondary flow at blade end and exit of guide vane. Due to the different blade numbers of guide vane and impeller, the total pressure distribution is asymmetric. This paper also simulates the flow under different working conditions to predict the hydraulic performances of centrifugal pump and external characteristics including flow-lift, flow-shaft power, and flow-efficiency are attained. The simulation results are compared with the experimental results, and because of the mechanical losses and volume loss ignored, there is a little difference between them.

  12. A new model of water-lubricated rubber bearings for vibration analysis of flexible multistage rotor systems

    Science.gov (United States)

    Liu, Shibing; Yang, Bingen

    2015-08-01

    Flexible multistage rotating systems that are supported or guided by long water-lubricated rubber bearings (WLRBs) have a variety of engineering applications. Vibration analysis of this type of machinery for performance and duality requires accurate modeling of WLRBs and related rotor-bearing assemblies. This work presents a new model of WLRBs, with attention given to the determination of bearing dynamic coefficients. Due to its large length-to-diameter ratio, a WLRB cannot be described by conventional pointwise bearing models with good fidelity. The bearing model proposed in this paper considers spatially distributed bearing forces. For the first time in the literature, the current study addresses the issue of mixed lubrication in the operation of WLRBs, which involves interactions of shaft vibration, elastic deformation of rubber material and fluid film pressure, and validates the WLRB model in experiments. Additionally, with the new bearing model, vibration analysis of WLRB-supported flexible multistage rotating systems is performed through use of a distributed transfer function method, which delivers accurate and closed-form analytical solutions of steady-state responses without discretization.

  13. Utilization of desulfurization gypsum to producing SO{sub 2} and CaO in multi-stage fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Zhu; Wang, Tao; Yang, Hairui; Zhang, Hai; Zhang, Zuyi [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Ministry of Education, Beijing (China). Key Lab. for Thermal Science and Power Engineering

    2013-07-01

    With emission control becomes more and more stringent, flue gas desulphurization (FGD) is commonly employed for desulfurization. However, the product of FGD, gypsum, causes the unexpected environmental problems. How to utilize the byproduct of FGD effectively and economically is a challenging task. This paper proposed the new technical process to produce SO{sub 2} and CaO by reducing the gypsum in multi-stage fluidized bed reactor with different atmosphere. In addition, some preliminary experiments were carried out in PTGA. The results show that CO concentration has little effect on the initial decomposing temperature, but affect the decomposing rate of phosphogypsum obviously. The decomposing product composed of CaS and CaO simultaneously. The ratio of the two products was determined by CO concentration. Lower CO content benefits to produce more CO product and more SO{sub 2}. The decomposition reaction of phosphogypsum in reducing atmosphere is parallel competition reaction. Therefore, it is necessary to eliminate the effect of CaS and other byproduct efficiently by the new technology, which utilize multi-atmosphere in multistage fluidized bed reactors.

  14. Application of multi-stage, multi-disk type downhole seismic source; Tadanshiki taso enbangata koseinai shingen no tekiyosei

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, N. [Japan National Oil Corp., Tokyo (Japan); Shoji, Y. [Oyo Corp., Tokyo (Japan)

    1997-05-27

    A multi-stage, multi-disk type seismic source was developed as a downhole seismic source. The seismic source is an improved version of the downhole seismic source of a system in which an elastic wave is generated by a weight accelerated by restitutive force of a spring striking the upper part of a laminated structure consisted of metal disks and elastic bodies installed in water in a well. Enhancing the vibration exciting efficiency requires impedance radiated from the disks to be increased. The multi-disk structure was adopted because of restrictions on the disk area under the limiting condition of being inside the well. Further limitation has still existed, which led to finally structuring the multi-disk type to a multi-stage construction to increase the radiated impedance. In order to increase average velocity on the radiation surface, mass relationship between the hammer and the anvil was sought so that the maximum velocity is achieved at the process of converting motion energies among the hammer, anvil and disks. The anvil mass may sufficiently be 50% to 100% of the hammer mass. The equipment was installed in an actual oil well for testing. This seismic source was verified to have sufficient applicability in the cross hole measurement. 5 refs., 7 figs., 1 tab.

  15. The influence of the "cage" effect on the mechanism of reversible bimolecular multistage chemical reactions proceeding from different sites in solutions.

    Science.gov (United States)

    Doktorov, Alexander B

    2016-08-28

    Manifestations of the "cage" effect at the encounters of reactants have been theoretically treated on the example of multistage reactions (including bimolecular exchange reactions as elementary stages) proceeding from different active sites in liquid solutions. It is shown that for reactions occurring near the contact of reactants, consistent consideration of quasi-stationary kinetics of such multistage reactions (possible in the framework of the encounter theory only) can be made on the basis of chemical concepts of the "cage complex," just as in the case of one-site model described in the literature. Exactly as in the one-site model, the presence of the "cage" effect gives rise to new channels of reactant transformation that cannot result from elementary event of chemical conversion for the given reaction mechanism. Besides, the multisite model demonstrates new (as compared to one-site model) features of multistage reaction course.

  16. Reverse engineering human neurodegenerative disease using pluripotent stem cell technology.

    Science.gov (United States)

    Liu, Ying; Deng, Wenbin

    2016-05-01

    With the technology of reprogramming somatic cells by introducing defined transcription factors that enables the generation of "induced pluripotent stem cells (iPSCs)" with pluripotency comparable to that of embryonic stem cells (ESCs), it has become possible to use this technology to produce various cells and tissues that have been difficult to obtain from living bodies. This advancement is bringing forth rapid progress in iPSC-based disease modeling, drug screening, and regenerative medicine. More and more studies have demonstrated that phenotypes of adult-onset neurodegenerative disorders could be rather faithfully recapitulated in iPSC-derived neural cell cultures. Moreover, despite the adult-onset nature of the diseases, pathogenic phenotypes and cellular abnormalities often exist in early developmental stages, providing new "windows of opportunity" for understanding mechanisms underlying neurodegenerative disorders and for discovering new medicines. The cell reprogramming technology enables a reverse engineering approach for modeling the cellular degenerative phenotypes of a wide range of human disorders. An excellent example is the study of the human neurodegenerative disease amyotrophic lateral sclerosis (ALS) using iPSCs. ALS is a progressive neurodegenerative disease characterized by the loss of upper and lower motor neurons (MNs), culminating in muscle wasting and death from respiratory failure. The iPSC approach provides innovative cell culture platforms to serve as ALS patient-derived model systems. Researchers have converted iPSCs derived from ALS patients into MNs and various types of glial cells, all of which are involved in ALS, to study the disease. The iPSC technology could be used to determine the role of specific genetic factors to track down what's wrong in the neurodegenerative disease process in the "disease-in-a-dish" model. Meanwhile, parallel experiments of targeting the same specific genes in human ESCs could also be performed to control

  17. A zircon vs titanite geochronometres by SHRIMP IIe as a tool in multistage magmatic intrusion problems

    Science.gov (United States)

    Wiszniewska, Janina; Krzemińska, Ewa

    2017-04-01

    reveal a relatively low uranium contents of about 11-30 ppm resulting in less precise U-Pb apparent ages overlapping 40 Ma (intercept age 1449 ±40 Ma). This age seems to be too young to be interpreted as a simple cooling age. The closure temperature (Tc) for the U-Pb system in titanite is assumed on the level of about 700°C. This younger and imprecise titanite age corresponds however with the youngest expressions of magmatism in this region, documented mostly within Lithuanian crystalline basement, where AMCG plutonic components are known from the Nemunas - Geluva granite suite with U-Pb (SIMS) zircon age in range of 1447 -1445±8Ma ( Skridalite et al. 2007). Dörr W., Belka Z., Marheine D., Schastok J., Valverde-Vaquero P., Wiszniewska J., 2002. U-Pb and Ar-Ar geochronology of anorogenic granite magmatism of the Mazury Complex, NE Poland. Precambrian Research, 119, 101-120. Skridlaite G. Whitehouse M. Rimsa A. 2007 Evidence for a pulse of 1.45 Ga anorthosite-mangerite-charnockite-granite (AMCG) plutonism in Lithuania: implications for the Mesoproterozoic evolution of the East European Craton, Terra Nova 19, 294-301. This is a contribution to the project; "Isotopic parameters of the Suwalki Anorthosite massif - an attempt to explain multistage Fe-Ti-V ore intrusion generation using titanite and apatite geochronometres by SHRIMP IIe " 61.2116.1601.09.0

  18. An investigation of rotor tip leakage flows in the rear-block of a multistage compressor

    Science.gov (United States)

    Brossman, John Richard

    measurements during this investigation. A detailed investigation and sensitivity analysis of the inlet flow field found the influence by the inlet total temperature profile was important to performance calculations. This finding was significant and original as previous investigations have been conducted on low-speed machines where there is minimal temperature rise. The steady state performance of the baseline 1.5% tip clearance case was outlined at design speed and three off-design speeds. The leakage flow from the rear seal, the inlet flow field and a thermal boundary condition over the casing was recorded at each operating point. Stage 1 was found to be the limiting stage independent of speed. Few datasets exist on multistage compressor performance with full boundary condition definitions, especially with off-design operating points presenting this as a unique dataset for CFD comparison. The detailed unsteady pressure measurements were conducted over Rotor 1 at design and a near-stall operating condition to characterize the leakage trajectory and position. The leakage flow initial point closer to the leading edge and trajectory angle increased at the higher loading condition. The over-the-rotor static pressure field on Rotor 1 indicated similar trends between the computational model and the leakage trajectory.

  19. An Experimental Characterization of Tip Leakage Flows and Corresponding Effects on Multistage Compressor Performance

    Science.gov (United States)

    Berdanier, Reid Adam

    The effect of rotor tip clearances in turbomachinery applications has been a primary research interest for nearly 80 years. Over that time, studies have shown increased tip clearance in axial flow compressors typically has a detrimental effect on overall pressure rise capability, isentropic efficiency, and stall margin. With modern engine designs trending toward decreased core sizes to increase propulsive efficiency (by increasing bypass ratio) or additional compression stages to increase thermal efficiency by increasing the overall pressure ratio, blade heights in the rear stages of the high pressure compressor are expected to decrease. These rear stages typically feature smaller blade aspect ratios, for which endwall flows are more important, and the rotor tip clearance height represents a larger fraction of blade span. As a result, data sets collected with large relative rotor tip clearance heights are necessary to facilitate these future small core design goals. This research seeks to characterize rotor tip leakage flows for three tip clearance heights in the Purdue three-stage axial compressor facility (1.5%, 3.0%, and 4.0% as a percentage of overall annulus height). The multistage environment of this compressor provides the unique opportunity to examine tip leakage flow effects due to stage matching, stator-rotor interactions, and rotor-rotor interactions. The important tip leakage flow effects which develop as a result of these interactions are absent for previous studies which have been conducted using single-stage machines or isolated rotors. A series of compressor performance maps comprise points at four corrected speeds for each of the three rotor tip clearance heights. Steady total pressure and total temperature measurements highlight the effects of tip leakage flows on radial profiles and wake shapes throughout the compressor. These data also evaluate tip clearance effects on efficiency, stall margin, and peak pressure rise capability. An emphasis of

  20. Statistics-enhanced multistage process models for integrated design &manufacturing of poly (vinyl alcohol) treated buckypaper

    Science.gov (United States)

    Wang, Kan

    Carbon nanotube (CNT) is considered a promising engineering material because of its exceptional mechanical, electrical, and thermal properties. Buckypaper (BP), a thin sheet of assembled CNTs, is an effective way to handle CNTs in macro scale. Pristine BP is a fragile material which is held together by weak van der Waals attractions among CNTs. This dissertation introduces a modified filtration based manufacturing process which uses poly (vinyl alcohol) (PVA) to treat BP. This treatment greatly improves the handleability of BP, reduces the spoilage during transferring, and shortens the production time. The multistage manufacturing process of PVA-treated BP is discussed in this dissertation, and process models are developed to predict the nanostructure of final products from the process parameters. Based on the nanostructure, a finite element based physical model for prediction of Young's modulus is also developed. This accuracy of this physical model is further improved by statistical methods. The aim of this study is to investigate and improve the scalability of the manufacturing process of PVA-treated BP. To achieve this goal, various statistical tools are employed. The unique issues in nanomanufacturing also motivate the development of new statistical tools and modification of existing tools. Those issues include the uncertainties in nanostructure characterization due to the scale, limited number experimental data due to high cost of raw materials, large variation in final product due to the random nature in structure, and the high complexity in physical models due to the small scale of structural building blocks. This dissertation addresses those issues by combining engineering field knowledge and statistical methods. The resulting statistics-enhanced physical model provides an approach to design the manufacturing process of PVA-treated BP for a targeting property and tailor the robustness of the final product by manipulating the process parameters. In addition

  1. Multi-stage 3D-2D registration for correction of anatomical deformation in image-guided spine surgery

    Science.gov (United States)

    Ketcha, M. D.; De Silva, T.; Uneri, A.; Jacobson, M. W.; Goerres, J.; Kleinszig, G.; Vogt, S.; Wolinsky, J.-P.; Siewerdsen, J. H.

    2017-06-01

    A multi-stage image-based 3D-2D registration method is presented that maps annotations in a 3D image (e.g. point labels annotating individual vertebrae in preoperative CT) to an intraoperative radiograph in which the patient has undergone non-rigid anatomical deformation due to changes in patient positioning or due to the intervention itself. The proposed method (termed msLevelCheck) extends a previous rigid registration solution (LevelCheck) to provide an accurate mapping of vertebral labels in the presence of spinal deformation. The method employs a multi-stage series of rigid 3D-2D registrations performed on sets of automatically determined and increasingly localized sub-images, with the final stage achieving a rigid mapping for each label to yield a locally rigid yet globally deformable solution. The method was evaluated first in a phantom study in which a CT image of the spine was acquired followed by a series of 7 mobile radiographs with increasing degree of deformation applied. Second, the method was validated using a clinical data set of patients exhibiting strong spinal deformation during thoracolumbar spine surgery. Registration accuracy was assessed using projection distance error (PDE) and failure rate (PDE  >  20 mm—i.e. label registered outside vertebra). The msLevelCheck method was able to register all vertebrae accurately for all cases of deformation in the phantom study, improving the maximum PDE of the rigid method from 22.4 mm to 3.9 mm. The clinical study demonstrated the feasibility of the approach in real patient data by accurately registering all vertebral labels in each case, eliminating all instances of failure encountered in the conventional rigid method. The multi-stage approach demonstrated accurate mapping of vertebral labels in the presence of strong spinal deformation. The msLevelCheck method maintains other advantageous aspects of the original LevelCheck method (e.g. compatibility with standard clinical workflow, large

  2. Multi-stage crustal growth and cratonization of the North China Craton

    Institute of Scientific and Technical Information of China (English)

    Mingguo Zhai

    2014-01-01

    The North China Craton (NCC) has a complicated evolutionary history with multi-stage crustal growth, recording nearly all important geological events in the early geotectonic history of the Earth. Our studies propose that the NCC can be divided into six micro-blocks with >w3.0e3.8 Ga old continental nuclei that are surrounded by Neoarchean greenstone belts (GRB). The micro-blocks are also termed as high-grade regions (HGR) and are mainly composed of orthogneisses with minor gabbros and BIF-bearing supracrustal beds or lenses, all of which underwent strong deformation and metamorphism of granu-lite-to high-grade amphibolite-facies. The micro-blocks are, in turn, from east to west, the Jiaoliao (JL), Qianhuai (QH), Ordos (ODS), Ji’ning (JN) and Alashan (ALS) blocks, and Xuchang (XCH) in the south. Recent studies led to a consensus that the basement of the NCC was composed of different blocks/ter-ranes that were finally amalgamated to form a coherent craton at the end of Neoarchean. Zircon U-Pb data show that TTG gneisses in the HGRs have two prominent age peaks at ca. 2.9e2.7 and 2.6e2.5 Ga which may correspond to the earliest events of major crustal growth in the NCC. Hafnium isotopic model ages range from ca. 3.8 to 2.5 Ga and mostly are in the range of 3.0e2.6 Ga with a peak at 2.82 Ga. Recent studies revealed a much larger volume of TTG gneisses in the NCC than previously considered, with a dominant ca. 2.7 Ga magmatic zircon ages. Most of the ca. 2.7 Ga TTG gneisses un-derwent metamorphism in 2.6e2.5 Ga as indicated by ubiquitous metamorphic rims around the cores of magmatic zircon in these rocks. Abundant ca. 2.6e2.5 Ga orthogneisses have Hf-in-zircon and Nd whole-rock model ages mostly around 2.9e2.7 Ga and some around 2.6e2.5 Ga, indicating the timing of pro-tolith formation or extraction of the protolith magma was from the mantle. Therefore, it is suggested that the 2.6e2.5 Ga TTGs probably represent a coherent event of continental accretion and major

  3. Simple multistage closed-(box+reservoir) models of chemical evolution: an application to the inner Galactic halo

    CERN Document Server

    Caimmi, R

    2010-01-01

    Simple closed-box (CB) models of chemical evolution are extended on two respects: (i) simple closed-(box+reservoir) (CBR) models allowing gas outflow from the box into the reservoir or gas inflow into the box from the reservoir with same composition as the preexisting gas and rate proportional to the star formation rate, and (ii) simple multistage closed-(box+reservoir) (MCBR) models allowing different stages of evolution characterized by different inflow or outflow rates. The stellar initial mass function is assumed to be universal, and mass conservation holds for the whole system (box+reservoir) while it is violated for each subsystem (box and reservoir). The theoretical differential oxygen abundance distribution (TDOD) predicted by the model, under the assumption of instantaneous recycling, is a continuous broken line, where different slopes are related to different inflow rates. For an application of the model (a) a fictitious sample is built up from two distinct samples and taken as representative of the...

  4. Evidence of Multi-Stage Hydrocarbon Charging and Biodegradation of the Silurian Asphaltic Sandstones in the Tarim Basin, China

    Institute of Scientific and Technical Information of China (English)

    刘洛夫

    2002-01-01

    Asphalts distributed widely in the Silurian sandstones of the Tarim Basin include dry asphalt, soft asphalt and heavy oil. These asphaltic sandstones underwent multi-episodic sedimentary and tectonic events, and their occurrence is diverse and complex, being mixed with normal oil usually. So far, very little work has been done on the asphaltic sandstone origin and hydrocarbon charging ages. After detailed study on the Silurian sandstones, the following highlights were obtained from the analytical results: distribution of the mixed asphalt, heavy oil and normal oil in the Silurian sandstones is the result of multi-stage hydrocarbon charging from the Lower Paleozoic marine source rocks; the characters of asphalts formed from oils of different charging ages are of difference; the most important process constraining.the asphaltic sandstone origin is thought to be biodegradation.

  5. Multiuser Detection Using Adaptive Multistage Matrix Wiener Filtering Schemes with Stage-Selection Criteria in DS-UWB

    Directory of Open Access Journals (Sweden)

    Hsuan-Yu Lin

    2008-11-01

    Full Text Available Adaptive reduced-rank (RR multistage matrix Wiener filtering (MMWF techniques, based on the minimum mean-square error (MMSE criterion, are proposed for direct-sequence (DS ultra-wideband (UWB communication systems. These RR-MMWF-based algorithms employ an adaptive fuzzy-inference determined filter stage. As a consequence, the proposed schemes achieve a substantial saving in complexity without compromising system performance and dynamic convergence/tracking capability. Additionally, the fuzzy-logic-controlled matrix conjugate gradient (MCG algorithm is developed for a robust and reduced-rank implementation of the full-rank MMWF. Simulations are conducted to illustrate the convergence/tracking superiority and to provide a comparative evaluation of the proposed algorithms with the MMWF-based schemes using other adaptive stage-selecting criteria.

  6. Flexible Design and Operation of Multi-Stage Flash (MSF Desalination Process Subject to Variable Fouling and Variable Freshwater Demand

    Directory of Open Access Journals (Sweden)

    Said Alforjani Said

    2013-10-01

    Full Text Available This work describes how the design and operation parameters of the Multi-Stage Flash (MSF desalination process are optimised when the process is subject to variation in seawater temperature, fouling and freshwater demand throughout the day. A simple polynomial based dynamic seawater temperature and variable freshwater demand correlations are developed based on actual data which are incorporated in the MSF mathematical model using gPROMS models builder 3.0.3. In addition, a fouling model based on stage temperature is considered. The fouling and the effect of noncondensable gases are incorporated into the calculation of overall heat transfer co-efficient for condensers. Finally, an optimisation problem is developed where the total daily operating cost of the MSF process is minimised by optimising the design (no of stages and the operating (seawater rejected flowrate and brine recycle flowrate parameters.

  7. Optimization of Realistic Multi-Stage Hybrid Flow Shop Scheduling Problems with Missing Operations Using Meta-Heuristics

    Directory of Open Access Journals (Sweden)

    M. Saravanan

    2014-03-01

    Full Text Available A Hybrid flow shop scheduling is characterized ‘n’ jobs ‘m’ machines with ‘M’ stages by unidirectional flow of work with a variety of jobs being processed sequentially in a single-pass manner. The paper addresses the multi-stage hybrid flow shop scheduling problems with missing operations. It occurs in many practical situations such as stainless steel manufacturing company. The essential complexity of the problem necessitates the application of meta-heuristics to solve hybrid flow shop scheduling. The proposed Simulated Annealing algorithm (SA compared with Particle Swarm Optimization (PSO with the objective of minimization of makespan. It is show that the SA algorithm is efficient in finding out good quality solutions for the hybrid flow shop problems with missing operations.

  8. A novel multi-stage subunit vaccine against paratuberculosis induces significant immunity and reduces bacterial burden in tissues (P4304)

    DEFF Research Database (Denmark)

    Thakur, Aneesh; Aagaard, Claus; Riber, Ulla;

    2013-01-01

    Effective control of paratuberculosis is hindered by lack of a vaccine preventing infection, transmission and without diagnostic interference with tuberculosis. We have developed a novel multi-stage recombinant subunit vaccine in which a fusion of four early expressed MAP antigens is combined...... with a MAP protein expressed in latent infection (FET11 vaccine). FET11 vaccine proteins were formulated with CAF01 adjuvant and injected to MAP challenged calves at two different ages. 28 calves divided into two FET11 vaccine groups, a commercial vaccine and a control group were used in the study...... and followed for a year. The FET11 vaccine induced a significant T cell response against constituent vaccine proteins characterized by a high percentage of CD4+ T cells and participation of polyfunctional CD4+ T cells. Of the two different age groups, late FET11 vaccination conferred protective immunity...

  9. Operational Modal Identification of Time-Varying Structures via a Vector Multistage Recursive Approach in Hybrid Time and Frequency Domain

    Directory of Open Access Journals (Sweden)

    Si-Da Zhou

    2015-01-01

    Full Text Available Real-time estimation of modal parameters of time-varying structures can conduct an obvious contribution to some specific applications in structural dynamic area, such as health monitoring, damage detection, and vibration control; the recursive algorithm of modal parameter estimation supplies one of fundamentals for acquiring modal parameters in real-time. This paper presents a vector multistage recursive method of modal parameter estimation for time-varying structures in hybrid time and frequency domain, including stages of recursive estimation of time-dependent power spectra, frozen-time modal parameter estimation, recursive modal validation, and continuous-time estimation of modal parameters. An experimental example validates the proposed method finally.

  10. PATIENT-CENTRED SCREENING FOR PRIMARY IMMUNODEFICIENCY, A MULTI-STAGE DIAGNOSTIC PROTOCOL DESIGNED FOR NONIMMUNOLOGISTS: 2011 UPDATE

    Directory of Open Access Journals (Sweden)

    E. de Vries

    2013-01-01

    Full Text Available Abstract. Members of the European Society for Immunodeficiencies (ESID and other colleagues have updated themulti-stage expert-opinion-based diagnostic protocol for non-immunologists incorporating newly defined primary immunodeficiency diseases (PIDs. The protocol presented here aims to increase the awareness of PIDs among doctors working in different fields. Prompt identification of PID is important for prognosis, but this may not be an easy task. The protocol therefore starts from the clinical presentation of the patient. Because PIDs may present at all ages, this protocol is aimed at both adult and paediatric physicians. The multi-stage design allows cost-effective screening for PID of the large number of potential cases in the early phases, with more expensive tests reserved for definitive classification in collaboration with a specialist in the field of immunodeficiency at a later stage.

  11. Effects of gear box vibration and mass imbalance on the dynamics of multi-stage gear transmissions

    Science.gov (United States)

    Choy, Fred K.; Tu, Yu K.; Zakrajsek, James J.; Townsend, Dennis P.

    1991-01-01

    The dynamic behavior of multistage gear transmission system, with the effects of gear-box-induced vibrations and rotor mass-imbalances is analyzed. The model method, using undamped frequencies and planar mode shapes, is used to reduce the degree-of-freedom of the system. The various rotor-bearing stages as well as lateral and torsional vibrations of each individual stage are coupled through localized gear-mesh-tooth interactions. Gear-box vibrations are coupled to the gear stage dynamics through bearing support forces. Transient and steady state dynamics of lateral and torsional vibrations of the geared system are examined in both time and frequency domain. A typical three-staged geared system is used as an example. Effects of mass-imbalance and gear box vibrations on the system dynamic behavior are presented in terms of modal excitation functions for both lateral and torsional vibrations. Operational characteristics and conclusions are drawn from the results presented.

  12. Aerodynamic design by jointly applying S2 flow surface calculation and modern optimization methods on multistage axial turbine

    Institute of Scientific and Technical Information of China (English)

    Honglei ZHAO; Songtao WANG; Wanjin HAN; Guotai FENG

    2008-01-01

    A three-stage axial turbine was redesigned by jointly applying S2 flow surface direct problem calculation methods and multistage local optimization methods. A genetic algorithm and artificial neural network were jointly adopted during optimization. A three-dimensional viscosity Navier-Stokes equation solver was applied for flow computation. H-O-H-topology grid was adopted as computation grid, that is, an H-topology grid was adopted for inlet and outlet segment, whereas an O-topology grid was adopted for stator zone and rotor zone. Through the optimization design, the total efficiency increases 1.1%, thus indicating that the total performance is improved and the design objective is achieved.

  13. Multi-stage optimization of decision and inhibitory trees for decision tables with many-valued decisions

    KAUST Repository

    Azad, Mohammad

    2017-06-16

    We study problems of optimization of decision and inhibitory trees for decision tables with many-valued decisions. As cost functions, we consider depth, average depth, number of nodes, and number of terminal/nonterminal nodes in trees. Decision tables with many-valued decisions (multi-label decision tables) are often more accurate models for real-life data sets than usual decision tables with single-valued decisions. Inhibitory trees can sometimes capture more information from decision tables than decision trees. In this paper, we create dynamic programming algorithms for multi-stage optimization of trees relative to a sequence of cost functions. We apply these algorithms to prove the existence of totally optimal (simultaneously optimal relative to a number of cost functions) decision and inhibitory trees for some modified decision tables from the UCI Machine Learning Repository.

  14. Modular Adaptive System Based on a Multi-Stage Neural Structure for Recognition of 2D Objects of Discontinuous Production

    Directory of Open Access Journals (Sweden)

    I. Topalova

    2008-11-01

    Full Text Available This is a presentation of a new system for invariant recognition of 2D objects with overlapping classes, that can not be effectively recognized with the traditional methods. The translation, scale and partial rotation invariant contour object description is transformed in a DCT spectrum space. The obtained frequency spectrums are decomposed into frequency bands in order to feed different BPG neural nets (NNs. The NNs are structured in three stages - filtering and full rotation invariance; partial recognition; general classification. The designed multi-stage BPG Neural Structure shows very good accuracy and flexibility when tested with 2D objects used in the discontinuous production. The reached speed and the opportunuty for an easy restructuring and reprogramming of the system makes it suitable for application in different applied systems for real time work.

  15. Multi-stage Continuous Culture Fermentation of Glucose-Xylose Mixtures to Fuel Ethanol using Genetically Engineered Saccharomyces cerevisiae 424A

    Science.gov (United States)

    Multi-stage continuous (chemostat) culture fermentation (MCCF) with variable fermentor volumes was carried out to study utilizing glucose and xylose for ethanol production by means of mixed sugar fermentation (MSF). Variable fermentor volumes were used to enable enhanced sugar u...

  16. High-dose rifampicin, moxifloxacin, and SQ109 for treating tuberculosis: a multi-arm, multi-stage randomised controlled trial

    NARCIS (Netherlands)

    Boeree, M.J.; Heinrich, N.; Aarnoutse, R.; Diacon, A.H.; Dawson, R.; Rehal, S.; Kibiki, G.S.; Churchyard, G.; Sanne, I.; Ntinginya, N.E.; Minja, L.T.; Hunt, R.D.; Charalambous, S.; Hanekom, M.; Semvua, H.H.; Mpagama, S.G.; Manyama, C.; Mtafya, B.; Reither, K.; Wallis, R.S.; Venter, A.; Narunsky, K.; Mekota, A.; Henne, S.; Colbers, A.; Balen, G.P. van; Gillespie, S.H.; Phillips, P.P.; Hoelscher, M.

    2017-01-01

    BACKGROUND: Tuberculosis is the world's leading infectious disease killer. We aimed to identify shorter, safer drug regimens for the treatment of tuberculosis. METHODS: We did a randomised controlled, open-label trial with a multi-arm, multi-stage design. The trial was done in seven sites in South A

  17. The gas-liquid mass transfer coefficient (k(L)a) in the gas-liquid Multi-stage Agitated Contactor (MAC)

    NARCIS (Netherlands)

    Breman, B.B; Beenackers, A.A C M; Bouma, M.J; VanderWerf, M.H.

    1996-01-01

    Data on the volumetric liquid-side gas-liquid mass transfer coefficient, k(L)a, in a Multi-stage Agitated Contractor (MAC) are reported for three gas-liquid systems (air-water, helium-n-octane, and air-Monoethylene Glycol (MEG)). k(L)a (s(-1)) was determined using a dynamic method with moderately so

  18. Multi-stage Continuous Culture Fermentation of Glucose-Xylose Mixtures to Fuel Ethanol using Genetically Engineered Saccharomyces cerevisiae 424A

    Science.gov (United States)

    Multi-stage continuous (chemostat) culture fermentation (MCCF) with variable fermentor volumes was carried out to study utilizing glucose and xylose for ethanol production by means of mixed sugar fermentation (MSF). Variable fermentor volumes were used to enable enhanced sugar u...

  19. A Multistage Longitudinal Comparative (MLC) Design Stage II: Evaluation of the Changing Lives Program (CLP)--The Possible Selves Questionnaire-Qualitative Extensions (PSQ-QE)

    Science.gov (United States)

    Kortsch, Gabrielle; Kurtines, William M.; Montgomery, Marilyn J.

    2008-01-01

    The study reported in this paper, a Multistage Longitudinal Comparative (MLC) Design Stage II evaluation conducted as a planned preliminary efficacy evaluation (psychometric evaluation of measures, short-term controlled outcome studies, etc.) of the Changing Lives Program (CLP), provided evidence for the reliability and validity of qualitative…

  20. A Multi-Stage Longitudinal Comparative Design Stage II Evaluation of the Changing Lives Program: The Life Course Interview (RDA-LCI)

    Science.gov (United States)

    Arango, Lisa Lewis; Kurtines, William M.; Montgomery, Marilyn J.; Ritchie, Rachel

    2008-01-01

    The study reported in this article, a Multi-Stage Longitudinal Comparative Design Stage II evaluation conducted as a planned preliminary efficacy evaluation (psychometric evaluation of measures, short-term controlled outcome studies, etc.) of the Changing Lives Program (CLP), provided evidence for the reliability and validity of the qualitative…

  1. Body Mass and Circumference of Upper Arm Are Associated with Race Performance in Ultraendurance Runners in a Multistage Race--The Isarrun 2006

    Science.gov (United States)

    Knechtle, Beat; Duff, Brida; Welzel, Ulrich; Kohler, Gotz

    2009-01-01

    In the present study, we investigated the association of anthropometric parameters with race performance in ultraendurance runners in a multistage ultraendurance run, in which athletes had to run 338 km within 5 consecutive days. In 17 male successful finishers, calculations of body mass, body height, skinfold thicknesses, extremity circumference,…

  2. The task of validation of gas-dynamic characteristics of a multistage centrifugal compressor for a natural gas booster compressor station

    Science.gov (United States)

    Danilishin, A. M.; Kozhukhov, Y. V.; Neverov, V. V.; Malev, K. G.; Mironov, Y. R.

    2017-08-01

    The aim of this work is the validation study for the numerical modeling of characteristics of a multistage centrifugal compressor for natural gas. In the research process was the analysis used grid interfaces and software systems. The result revealed discrepancies between the simulated and experimental characteristics and outlined the future work plan.

  3. The discriminative power of the Interval Shuttle Run Test and the Maximal Multistage Shuttle Run Test for playing level of soccer

    NARCIS (Netherlands)

    Lemmink, K.A.P.M.; Verheijen, R.; Visscher, C.

    2004-01-01

    AIM: The purpose of this study was to examine the discriminative power of the recently developed Interval Shuttle Run Test (ISRT) and the widely used Maximal Multistage 20 m Shuttle Run Test (MMSRT) for soccer players at different levels of competition. The main difference between the tests is that

  4. Do Human-Figure Drawings of Children and Adolescents Mirror Their Cognitive Style and Self-Esteem?

    Science.gov (United States)

    Dey, Anindita; Ghosh, Paromita

    2016-01-01

    The investigation probed relationships among human-figure drawing, field-dependent-independent cognitive style and self-esteem of 10-15 year olds. It also attempted to predict human-figure drawing scores of participants based on their field-dependence-independence and self-esteem. Area, stratified and multi-stage random sampling were used to…

  5. Do Human-Figure Drawings of Children and Adolescents Mirror Their Cognitive Style and Self-Esteem?

    Science.gov (United States)

    Dey, Anindita; Ghosh, Paromita

    2016-01-01

    The investigation probed relationships among human-figure drawing, field-dependent-independent cognitive style and self-esteem of 10-15 year olds. It also attempted to predict human-figure drawing scores of participants based on their field-dependence-independence and self-esteem. Area, stratified and multi-stage random sampling were used to…

  6. Multistage bioassociation of uranium onto an extremely halophilic archaeon revealed by a unique combination of spectroscopic and microscopic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bader, Miriam; Müller, Katharina; Foerstendorf, Harald; Drobot, Björn [Helmholtz-Zentrum Dresden – Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden (Germany); Schmidt, Matthias; Musat, Niculina [Helmholtz Centre for Environmental Research–UFZ, Department of Isotope Biogeochemistry, Permoserstraße 15, 04318 Leipzig (Germany); Swanson, Juliet S.; Reed, Donald T. [Los Alamos National Laboratory, Repository Science and Operations, 1400 University Drive, Carlsbad, NM, 88220 (United States); Stumpf, Thorsten [Helmholtz-Zentrum Dresden – Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden (Germany); Cherkouk, Andrea, E-mail: a.cherkouk@hzdr.de [Helmholtz-Zentrum Dresden – Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden (Germany)

    2017-04-05

    Highlights: • First prolonged kinetics study of uranium to halophilic archaea was performed. • An atypical time-dependent bioassociation behavior of uranium was observed. • Unique combination of spectroscopic and microscopic methods was used. • In situ ATR FT-IR showed association of U(VI) to phosphoryl and carboxylate groups. • Time-dependent changes of U(VI) localization could be monitored by SEM/EDX. - Abstract: The interactions of two extremely halophilic archaea with uranium were investigated at high ionic strength as a function of time, pH and uranium concentration. Halobacterium noricense DSM-15987 and Halobacterium sp. putatively noricense, isolated from the Waste Isolation Pilot Plant repository, were used for these investigations. The kinetics of U(VI) bioassociation with both strains showed an atypical multistage behavior, meaning that after an initial phase of U(VI) sorption, an unexpected interim period of U(VI) release was observed, followed by a slow reassociation of uranium with the cells. By applying in situ attenuated total reflection Fourier-transform infrared spectroscopy, the involvement of phosphoryl and carboxylate groups in U(VI) complexation during the first biosorption phase was shown. Differences in cell morphology and uranium localization become visible at different stages of the bioassociation process, as shown with scanning electron microscopy in combination with energy dispersive X-ray spectroscopy. Our results demonstrate for the first time that association of uranium with the extremely halophilic archaeon is a multistage process, beginning with sorption and followed by another process, probably biomineralization.

  7. Supergene neoformation of Pt-Ir-Fe-Ni alloys: multistage grains explain nugget formation in Ni-laterites

    Science.gov (United States)

    Aiglsperger, Thomas; Proenza, Joaquín A.; Font-Bardia, Mercè; Baurier-Aymat, Sandra; Galí, Salvador; Lewis, John F.; Longo, Francisco

    2016-11-01

    Ni-laterites from the Dominican Republic host rare but extremely platinum-group element (PGE)-rich chromitites (up to 17.5 ppm) without economic significance. These chromitites occur either included in saprolite (beneath the Mg discontinuity) or as `floating chromitites' within limonite (above the Mg discontinuity). Both chromitite types have similar iridium-group PGE (IPGE)-enriched chondrite normalized patterns; however, chromitites included in limonite show a pronounced positive Pt anomaly. Investigation of heavy mineral concentrates, obtained via hydroseparation techniques, led to the discovery of multistage PGE grains: (i) Os-Ru-Fe-(Ir) grains of porous appearance are overgrown by (ii) Ni-Fe-Ir and Ir-Fe-Ni-(Pt) phases which are overgrown by (iii) Pt-Ir-Fe-Ni mineral phases. Whereas Ir-dominated overgrowths prevail in chromitites from the saprolite, Pt-dominated overgrowths are observed within floating chromitites. The following formation model for multistage PGE grains is discussed: (i) hypogene platinum-group minerals (PGM) (e.g. laurite) are transformed to secondary PGM by desulphurization during serpentinization; (ii) at the stages of serpentinization and/or at the early stages of lateritization, Ir is mobilized and recrystallizes on porous surfaces of secondary PGM (serving as a natural catalyst) and (iii) at the late stages of lateritization, biogenic mediated neoformation (and accumulation) of Pt-Ir-Fe-Ni nanoparticles occurs. The evidence presented in this work demonstrates that in situ growth of Pt-Ir-Fe-Ni alloy nuggets of isometric symmetry is possible within Ni-laterites from the Dominican Republic.

  8. Total water production capacity inversion phenomenon in multi-stage direct contact membrane distillation: A theoretical study

    KAUST Repository

    Lee, Jung Gil

    2017-09-09

    The low thermal efficiency and low water production are among the major challenges that prevent membrane distillation (MD) process from being commercialized. In an effort to design an efficient multi-stage direct contact MD (DCMD) unit through mathematical simulation, a new phenomenon that we refer to as total water production capacity inversion (WPI) has been detected. It is represented by a decrease in the total water production beyond a number of stages or a certain module length. WPI phenomenon, which was confirmed by using two different mathematical models validated experimentally, was found to take place due to the decrease in water vapor flux across the membrane as well as the increase in heat loss by conduction as the membrane length increases. Therefore, WPI should be considered as a critical MD design-criterion, especially for large scale units. Investigations conducted for a simulated multi-stage DCMD process showed that inlet feed and permeate temperatures difference, feed and permeate flow rates, and feed salinity have different effects on WPI. The number of stages (or module length at constant width) that leads to a maximum water production has been determined for different operating parameters. Decreasing inlet feed and permeate temperatures difference, or inlet feed and permeate flow rates and increasing inlet feed temperature at constant temperature difference or inlet feed salinity cause the WPI to take place at lower number of stages. Even though the feed salinity affects negligibly the mean permeate flux, it was clearly shown that it can affect WPI. The results presented herein unveil a hidden phenomenon that is likely to occur during process scale-up procedures and should be considered by process engineers for a proper choice of system design and operating conditions.

  9. Optimization of Multistage Extraction of Olive Leaves for Recovery of Phenolic Compounds at Moderated Temperatures and Short Extraction Times

    Directory of Open Access Journals (Sweden)

    Konstantinos Stamatopoulos

    2013-12-01

    Full Text Available The aim of the present study was to improve the recovery of polyphenols from olive leaves (OL by optimizing a multistage extraction scheme; provided that the olive leaves have been previously steam blanched. The maximum total phenol content expressed in ppm caffeic acid equivalents was obtained at pH 2, particle size 0.315 mm, solid-liquid ratio 1:7 and aqueous ethanol concentration 70% (v/v. The optimum duration time of each extraction stage and the operation temperature, were chosen based on qualitative and quantitative analysis of oleuropein (OLE, verbascoside, luteolin-7-O-glucoside and apigenin-7-O-glucoside performed by high performance liquid chromatography with diode array detector (HPLC-DAD. The optimum conditions for multistage extraction were 30 min total extraction time (10 min × 3 stages at 85 °C. The 80% of the total yield of polyphenols was obtained at the 1st stage of the extraction. The total extraction yield of oleuropein was found 23 times higher (103.1 mg OLE/g dry weight (d.w. OL compared to the yield (4.6 mg OLE/g d.w. OL obtained by the conventional extraction method (40 °C, 48 h. However, from an energetic and hence from an economical point of view it is preferable to work at 40 °C, since the total extraction yield of polyphenolic compounds was only 17% higher for a double increase in the operating temperature (i.e., 85 °C.

  10. Design of a multi-stage microfluidics system for high-speed flow cytometry and closed system cell sorting for cytomics

    Science.gov (United States)

    Grafton, Meggie; Reece, Lisa M.; Irazoqui, Pedro P.; Jung, Byunghoo; Summers, Huw D.; Bashir, Rashid; Leary, James F.

    2008-02-01

    To produce a large increase in total throughput, a multi-stage microfluidics system (US Patent pending) is being developed for flow cytometry and closed system cell sorting. The multi-stage system provides for sorting and re-sorting of cohorts of cells beginning with multiple cells per sorting unit in the initial stages of the microfluidic device and achieving single cell sorting at subsequent stages. This design theoretically promises increases of 2- or 3-orders of magnitude in total cell throughput needed for cytomics applications involving gene chip or proteomics analyses of sorted cell subpopulations. Briefly, silicon wafers and CAD software were used with SU-8 soft photolithography techniques and used as a mold to create Y-shaped, multi-stage microfluidic PDMS chips. PDMS microfluidic chips were fabricated and tested using fluorescent microspheres driven through the chip by a microprocessor-controlled syringe drive and excited on an inverted Nikon fluorescence microscope. Inter-particle spacings were measured and used as experimental data for queuing theory models of multi-stage system performance. A miniaturized electronics system is being developed for a small portable instrument. A variety of LED light sources, waveguides, and APD detectors are being tested to find optimal combinations for creating an LED-APD configuration at the entry points of the Y-junctions for the multi-stage optical PDMS microfluidic chips. The LEDs, APDs, and PDMS chips are being combined into an inexpensive, small portable, closed system sorter suitable for operation inside a standard biohazard hood for both sterility and closed system cell sorting as an alternative to large, expensive, and conventional droplet-based cell sorters.

  11. The novel Candida albicans transporter Dur31 Is a multi-stage pathogenicity factor.

    Directory of Open Access Journals (Sweden)

    François L Mayer

    Full Text Available Candida albicans is the most frequent cause of oral fungal infections. However, the exact pathogenicity mechanisms that this fungus employs are largely unknown and many of the genes expressed during oral infection are uncharacterized. In this study we sought to functionally characterize 12 previously unknown function genes associated with oral candidiasis. We generated homozygous knockout mutants for all 12 genes and analyzed their interaction with human oral epithelium in vitro. Eleven mutants caused significantly less epithelial damage and, of these, deletion of orf19.6656 (DUR31 elicited the strongest reduction in pathogenicity. Interestingly, DUR31 was not only involved in oral epithelial damage, but in multiple stages of candidiasis, including surviving attack by human neutrophils, endothelial damage and virulence in vivo. In silico analysis indicated that DUR31 encodes a sodium/substrate symporter with 13 transmembrane domains and no human homologue. We provide evidence that Dur31 transports histatin 5. This is one of the very first examples of microbial driven import of this highly cytotoxic antimicrobial peptide. Also, in contrast to wild type C. albicans, dur31Δ/Δ was unable to actively increase local environmental pH, suggesting that Dur31 lies in the extracellular alkalinization hyphal auto-induction pathway; and, indeed, DUR31 was required for morphogenesis. In agreement with this observation, dur31Δ/Δ was unable to assimilate the polyamine spermidine.

  12. Non-integrating episomal plasmid-based reprogramming of human amniotic fluid stem cells into induced pluripotent stem cells in chemically defined conditions.

    Science.gov (United States)

    Slamecka, Jaroslav; Salimova, Lilia; McClellan, Steven; van Kelle, Mathieu; Kehl, Debora; Laurini, Javier; Cinelli, Paolo; Owen, Laurie; Hoerstrup, Simon P; Weber, Benedikt

    2016-01-01

    Amniotic fluid stem cells (AFSC) represent an attractive potential cell source for fetal and pediatric cell-based therapies. However, upgrading them to pluripotency confers refractoriness toward senescence, higher proliferation rate and unlimited differentiation potential. AFSC were observed to rapidly and efficiently reacquire pluripotency which together with their easy recovery makes them an attractive cell source for reprogramming. The reprogramming process as well as the resulting iPSC epigenome could potentially benefit from the unspecialized nature of AFSC. iPSC derived from AFSC also have potential in disease modeling, such as Down syndrome or β-thalassemia. Previous experiments involving AFSC reprogramming have largely relied on integrative vector transgene delivery and undefined serum-containing, feeder-dependent culture. Here, we describe non-integrative oriP/EBNA-1 episomal plasmid-based reprogramming of AFSC into iPSC and culture in fully chemically defined xeno-free conditions represented by vitronectin coating and E8 medium, a system that we found uniquely suited for this purpose. The derived AF-iPSC lines uniformly expressed a set of pluripotency markers Oct3/4, Nanog, Sox2, SSEA-1, SSEA-4, TRA-1-60, TRA-1-81 in a pattern typical for human primed PSC. Additionally, the cells formed teratomas, and were deemed pluripotent by PluriTest, a global expression microarray-based in-silico pluripotency assay. However, we found that the PluriTest scores were borderline, indicating a unique pluripotent signature in the defined condition. In the light of potential future clinical translation of iPSC technology, non-integrating reprogramming and chemically defined culture are more acceptable.

  13. Sarcoidosis-Associated Aortoesophageal Fistula-Multistage Interdisciplinary Surgical Therapy for a Rare and Life-Threatening Condition.

    Science.gov (United States)

    Gombert, Alexander; Grommes, Jochen; Schick, Guido; Binnebösel, Marcel; Klink, Christian; Jacobs, Michael J; Kotelis, Drosos

    2017-02-01

    Aortoesophageal fistulas (AEFs) are rare and life-threatening conditions. Till date, an association between an AEF and sarcoidosis has not been reported yet. The aim of this report is to demonstrate a case of AEF secondary to sarcoidosis and its multistage interdisciplinary surgical therapy. A 66-year-old male was diagnosed with sarcoidosis in 2014. He has been treated with glucocorticoids since then and no severe health restrictions due to the disease have occurred. In December 2015, the patient presented with acute thoracic pain and hematemesis: an esophagogastroscopy revealed an AEF. First, stent-graft implantation in the thoracic aorta was urgently performed as a "bridging" procedure. Second, esophagectomy and local debridement were performed, followed by explantation of the stent graft and reconstruction by means of xenograft replacement of the stented aorta in a third operation. Finally, retrosternal gastric pull-up was performed in a fourth operative procedure. Sixteen days after the last operation the patient could be discharged to a rehabilitation clinic. Follow-up is uneventful so far; the antibiotic therapy was stopped at the time of hospital discharge. The pathogenesis of sarcoidosis, a rare autoimmunological disease, has not been completely clarified yet. The diagnosis relies on clinical symptoms and radiological as well as histopathological findings. Many cases of sarcoidosis show spontaneous regression, but severe complications may occur. While tracheoesophageal fistulas have been described in the literature, AEFs related to sarcoidosis have not been mentioned yet. Despite surgical and antibiotic treatment, the morbidity and mortality rates of AEF are high. Because the endovascular treatment has been established for emergency procedures of the aorta, it is considered as an appropriate first-line "bridging" treatment option. To achieve good long-term results, surgical treatment has to involve esophagectomy with secondary reconstruction of the upper

  14. Low Energy Multi-Stage Atrial Defibrillation Therapy Terminates Atrial Fibrillation with Less Energy than a Single Shock

    Science.gov (United States)

    Li, Wenwen; Janardhan, Ajit H.; Fedorov, Vadim V.; Sha, Qun; Schuessler, Richard B.; Efimov, Igor R.

    2011-01-01

    Background Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multi-stage defibrillation therapy and tested it in a canine model of AF. Methods and Results AF was induced by burst pacing during vagus nerve stimulation. Our novel defibrillation therapy consisted of three stages: ST1 (1-4 low energy biphasic shocks), ST2 (6-10 ultra-low energy monophasic shocks), and ST3 (anti-tachycardia pacing). Firstly, ST1 testing compared single or multiple monophasic (MP) and biphasic (BP) shocks. Secondly, several multi-stage therapies were tested: ST1 versus ST1+ST3 versus ST1+ST2+ST3. Thirdly, three shock vectors were compared: superior vena cava to distal coronary sinus (SVC>CSd), proximal coronary sinus to left atrial appendage (CSp>LAA) and right atrial appendage to left atrial appendage (RAA>LAA). The atrial defibrillation threshold (DFT) of 1BP shock was less than 1MP shock (0.55 ± 0.1 versus 1.38 ± 0.31 J; p =0.003). 2-3 BP shocks terminated AF with lower peak voltage than 1BP or 1MP shock and with lower atrial DFT than 4 BP shocks. Compared to ST1 therapy alone, ST1+ST3 lowered the atrial DFT moderately (0.51 ± 0.46 versus 0.95 ± 0.32 J; p = 0.036) while a three-stage therapy, ST1+ST2+ST3, dramatically lowered the atrial DFT (0.19 ± 0.12 J versus 0.95 ± 0.32 J for ST1 alone, p=0.0012). Finally, the three-stage therapy ST1+ST2+ST3 was equally effective for all studied vectors. Conclusions Three-stage electrotherapy significantly reduces the AF defibrillation threshold and opens the door to low energy atrial defibrillation at or below the pain threshold. PMID:21980076

  15. Optimization of atrazine and imidacloprid removal from water using biochars: Designing single or multi-staged batch adsorption systems.

    Science.gov (United States)

    Mandal, Abhishek; Singh, Neera

    2017-05-01

    Contamination of surface and ground water by pesticides from agricultural runoff and industrial discharge is one of the main causes of aqueous contaminations world over. Biochar, agricultural waste derived highly aromatic substance produced after pyrolysis and carbonification of biomass have exhibited good adsorption capacity for pesticides and can be used to develop on-site bio-purification systems for organic contaminant removal from polluted waters. However, high amounts of adsorbent required in single stage-batch sorption plant increases the cost of water treatment; therefore, multistage plant systems were investigated. Normal (RSBC) and phosphoric acid treated (T-RSBC) rice straw biochars were evaluated for atrazine and imidacloprid sorption and data fitted to the Freundlich isotherm. The adsorption data was modelled to develop single or multi-staged adsorber plants for pesticide removal from water. Both biochars showed significantly high adsorption capacity for imidacloprid and atrazine. Modelling studies using the Freundlich adsorption parameters suggested that the amounts (kg/1000L) of RSBC and T-RSBC for 95% of atrazine removal (10mg/L) in single-, two- and three-staged adsorber plant models were 8.84, 2.44, 1.61kg and 4.47, 1.42, 0.98kg, respectively. Corresponding amounts for 95% imidacloprid removal (10mg/L) were 3.97, 1.22, 0.84kg and 3.98, 1.38, 0.96kg, respectively. Thus, the two-staged model suggested 65-72% reduction in amount of adsorbent required over the single stage model, while the three-staged model suggested 30-34% adsorbent saving over the two-staged plant model. Single and two-staged adsorber plant model findings were validated for atrazine removal using T-RSBC. Results suggested that amounts calculated using modelling studies were fairly accurate. Biochars, as low cost adsorbents for atrazine and imidacloprid removal from contaminated water, can be used to develop low cost adsorber plants based on multiple batch sorption systems for the

  16. Anti-NMDA-receptor encephalitis: a severe, multistage, treatable disorder presenting with psychosis.

    Science.gov (United States)

    Wandinger, Klaus-Peter; Saschenbrecker, Sandra; Stoecker, Winfried; Dalmau, Josep

    2011-02-01

    Anti-NMDA-receptor encephalitis is a severe, treatable and potentially reversible disorder presenting with memory deficits, psychiatric symptoms and seizures. Initially described in young patients with ovarian teratoma, the disease is meanwhile increasingly recognized also in women without tumours, in men and in children. The presence of anti-glutamate receptor (type NMDA) autoantibodies in serum or cerebrospinal fluid is specific for this novel and widely underdiagnosed disorder. Early recognition is crucial since prognosis largely depends on adequate immunotherapy and, in paraneoplastic cases, complete tumour removal. Indirect immunofluorescence using NMDA-type glutamate receptors recombinantly expressed in human cells is a highly competent method for diagnosing anti-NMDA-receptor encephalitis.

  17. Bioreactors for high cell density and continuous multi-stage cultivations: options for process intensification in cell culture-based viral vaccine production.

    Science.gov (United States)

    Tapia, Felipe; Vázquez-Ramírez, Daniel; Genzel, Yvonne; Reichl, Udo

    2016-03-01

    With an increasing demand for efficacious, safe, and affordable vaccines for human and animal use, process intensification in cell culture-based viral vaccine production demands advanced process strategies to overcome the limitations of conventional batch cultivations. However, the use of fed-batch, perfusion, or continuous modes to drive processes at high cell density (HCD) and overextended operating times has so far been little explored in large-scale viral vaccine manufacturing. Also, possible reductions in cell-specific virus yields for HCD cultivations have been reported frequently. Taking into account that vaccine production is one of the most heavily regulated industries in the pharmaceutical sector with tough margins to meet, it is understandable that process intensification is being considered by both academia and industry as a next step toward more efficient viral vaccine production processes only recently. Compared to conventional batch processes, fed-batch and perfusion strategies could result in ten to a hundred times higher product yields. Both cultivation strategies can be implemented to achieve cell concentrations exceeding 10(7) cells/mL or even 10(8) cells/mL, while keeping low levels of metabolites that potentially inhibit cell growth and virus replication. The trend towards HCD processes is supported by development of GMP-compliant cultivation platforms, i.e., acoustic settlers, hollow fiber bioreactors, and hollow fiber-based perfusion systems including tangential flow filtration (TFF) or alternating tangential flow (ATF) technologies. In this review, these process modes are discussed in detail and compared with conventional batch processes based on productivity indicators such as space-time yield, cell concentration, and product titers. In addition, options for the production of viral vaccines in continuous multi-stage bioreactors such as two- and three-stage systems are addressed. While such systems have shown similar virus titers compared to

  18. Thermal modelling of the multi-stage heating system with variable boundary conditions in the wafer based precision glass moulding process

    DEFF Research Database (Denmark)

    Sarhadi, Ali; Hattel, Jesper Henri; Hansen, Hans Nørgaard;

    2012-01-01

    of the heating system in the glass moulding process considering detailed heating mechanisms therefore plays an important part in optimizing the heating system and the subsequent pressing stage in the lens manufacturing process.The current paper deals with three-dimensional transient thermal modelling...... of the multi-stage heating system in a wafer based glass moulding process. In order to investigate the importance of the radiation from the interior and surface of the glass, a simple finite volume code is developed to model one dimensional radiation–conduction heat transfer in the glass wafer for an extreme...... pressures. Finally, the three-dimensional modelling of the multi-stage heating system in the wafer based glass moulding process is simulated with the FEM software ABAQUS for a particular industrial application for mobile phone camera lenses to obtain the temperature distribution in the glass wafer...

  19. Detection of Botnet Command and Control Traffic by the Multistage Trust Evaluation of Destination Identifiers

    Directory of Open Access Journals (Sweden)

    Pieter Burghouwt

    2015-10-01

    Full Text Available Network-based detection of botnet Command and Control communication is a difficult task if the traffic has a relatively low volume and if popular protocols, such as HTTP, are used to resemble normal traffic. We present a new network-based detection approach that is capable of detecting this type of Command and Control traffic in an enterprise network by estimating the trustworthiness of the traffic destinations. If the destination identifier of a traffic flow origins directly from: human input, prior traffic from a trusted destination, or a defined set of legitimate applications, the destination is trusted and its associated traffic is classified as normal. Advantages of this approach are: the ability of zero day malicious traffic detection, low exposure to malware by passive host-external traffic monitoring, and the applicability for real-time filtering. Experimental evaluation demonstrates successful detection of diverse types of Command and Control Traffic.

  20. Multi-Stage Feature Selection by Using Genetic Algorithms for Fault Diagnosis in Gearboxes Based on Vibration Signal

    Directory of Open Access Journals (Sweden)

    Mariela Cerrada

    2015-09-01

    Full Text Available There are growing demands for condition-based monitoring of gearboxes, and techniques to improve the reliability, effectiveness and accuracy for fault diagnosis are considered valuable contributions. Feature selection is still an important aspect in machine learning-based diagnosis in order to reach good performance in the diagnosis system. The main aim of this research is to propose a multi-stage feature selection mechanism for selecting the best set of condition parameters on the time, frequency and time-frequency domains, which are extracted from vibration signals for fault diagnosis purposes in gearboxes. The selection is based on genetic algorithms, proposing in each stage a new subset of the best features regarding the classifier performance in a supervised environment. The selected features are augmented at each stage and used as input for a neural network classifier in the next step, while a new subset of feature candidates is treated by the selection process. As a result, the inherent exploration and exploitation of the genetic algorithms for finding the best solutions of the selection problem are locally focused. The Sensors 2015, 15 23904 approach is tested on a dataset from a real test bed with several fault classes under different running conditions of load and velocity. The model performance for diagnosis is over 98%.

  1. New concepts in the management of diffuse low-grade glioma: Proposal of a multistage and individualized therapeutic approach.

    Science.gov (United States)

    Duffau, Hugues; Taillandier, Luc

    2015-03-01

    Diffuse low-grade glioma grows, migrates along white matter tracts, and progresses to high-grade glioma. Rather than a "wait and see" policy, an aggressive attitude is now recommended, with early surgery as the first therapy. Intraoperative mapping, with maximal resection according to functional boundaries, is associated with a longer overall survival (OS) while minimizing morbidity. However, most studies have investigated the role of only one specific treatment (surgery, radiotherapy, chemotherapy) without taking a global view of managing the cumulative time while preserving quality of life (QoL) versus time to anaplastic transformation. Our aim is to switch towards a more holistic concept based upon the anticipation of a personalized and long-term multistage therapeutic approach, with online adaptation of the strategy over the years using feedback from clinical, radiological, and histomolecular monitoring. This dynamic strategy challenges the traditional approach by proposing earlier therapy, by repeating treatments, and by reversing the classical order of therapies (eg, neoadjuvant chemotherapy when maximal resection is impossible, no early radiotherapy) to improve OS and QoL. New individualized management strategies should deal with the interactions between the course of this chronic disease, reaction brain remapping, and oncofunctional modulation elicited by serial treatments. This philosophy supports a personalized, functional, and preventive neuro-oncology. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Analysis of mixing conditions and multistage irradiation impact on NOx removal efficiency in the electron beam flue gas treatment process.

    Science.gov (United States)

    Pawelec, Andrzej; Dobrowolski, Andrzej

    2017-01-01

    In the process of electron beam flue gas treatment (EBFGT), most energy is spent on NOx removal. The dose distribution in the reactor is not uniform and the flue gas flow pattern plays an important role in the process efficiency. It was found that proper construction of the reactor may increase the energy efficiency of the process. The impact of the number of irradiation stages and mixing conditions on NOx removal efficiency was investigated for an ideal case and a practical solution was presented and compared with previously known EBFGT reactor constructions. The research was performed by means of computational fluid dynamics methods in combination with empirical Wittig formula. Two versions of dose distribution were taken for calculations. The results of the research show that for an ideal case, application of multistage irradiation and interstage mixing may reduce the energy consumption in the process by up to 39%. On the other side, simulation of reactor construction modification for two-stage irradiation results in 25% energy consumption reduction. The results of presented case study may be applied for improving the existing reactors and proper design of future installations.

  3. Free-face-Assisted Rock Breaking Method Based on the Multi-stage Tunnel Boring Machine (TBM) Cutterhead

    Science.gov (United States)

    Geng, Qi; Wei, Zhengying; Meng, Hao; Macias, Francisco Javier; Bruland, Amund

    2016-11-01

    In order to improve the rock breaking efficiency of hard rock tunnel boring, many innovative rock breaking methods have been proposed (e.g., the water jet cutting, the high-power laser cutting, the impact-rotary drilling, and the undercutting method). However, most of the methods are not applicable to TBMs due to some structural reasons. Aiming on this problem, a free-face-assisted rock breaking method based on the multi-stage TBM cutterhead has been proposed. Series of proof-of-concept tests includes (1) the static compression test with vertical free face and (2) the rotary cutting tests in different free surface conditions were designed and carried out. The results show that the rock breaking force and efficiency can be significantly reduced and improved, respectively, with the assistance of the free face, due to the failure of the rock close to the free face is tensile-dominated failure. The influencing distance of the free face in the radial direction is at least 330 mm which covers about 5 disk cutters. Finally, the general structure of a small two-stage cutterhead (4 m in diameter) was tentatively designed in order to provide a possible approach to apply the free-face effect to TBMs.

  4. Performance assessment and transient optimization of multi-stage solid desiccant air conditioning systems with building PV/T integration

    Science.gov (United States)

    Gadalla, Mohamed; Saghafifar, Mohammad

    2016-09-01

    One of the popular solar air conditioning technologies is desiccant air conditioning. Nonetheless, single stage desiccant air conditioning systems' coefficient of performance (COP) are relatively low. Therefore, multi-stage solid desiccant air conditioning systems are recommended. In this paper, an integrated double-stage desiccant air conditioning systems and PV/T collector is suggested for hot and humid climates such as the UAE. The results for the PV/T implementation in the double-stage desiccant cooling system are assessed against the PV/T results for a single-stage desiccant air conditioning system. In order to provide a valid comparative evaluation between the single and double stage desiccant air conditioning systems, an identical PV/T module, in terms of dimensions, is incorporated into these systems. The overall required auxiliary air heating is abated by 46.0% from 386.8 MWh to 209.0 MWh by replacing the single stage desiccant air conditioning system with the proposed double stage configuration during June to October. Moreover, the overall averaged solar share during the investigated months for the single and double stage systems are 36.5% and 43.3%.

  5. Hamilton–Jacobi–Bellman equations and dynamic programming for power-optimization of radiative law multistage heat engine system

    Directory of Open Access Journals (Sweden)

    Shaojun Xia, Lingen Chen, Fengrui Sun

    2012-01-01

    Full Text Available A multistage endoreversible Carnot heat engine system operating with a finite thermal capacity high-temperature black photon fluid reservoir and the heat transfer law is investigated in this paper. Optimal control theory is applied to derive the continuous Hamilton-Jacobi-Bellman (HJB equations, which determine the optimal fluid temperature configurations for maximum power output under the conditions of fixed initial time and fixed initial temperature of the driving fluid. Based on the general optimization results, the analytical solution for the case with pseudo-Newtonian heat transfer law is further obtained. Since there are no analytical solutions for the radiative heat transfer law, the continuous HJB equations are discretized and the dynamic programming (DP algorithm is adopted to obtain the complete numerical solutions, and the relationships among the maximum power output of the system, the process period and the fluid temperatures are discussed in detail. The optimization results obtained for the radiative heat transfer law are also compared with those obtained for pseudo-Newtonian heat transfer law and stage-by-stage optimization strategy. The obtained results can provide some theoretical guidelines for the optimal designs and operations of solar energy conversion and transfer systems.

  6. Developing optimum sample size and multistage sampling plans for Lobesia botrana (Lepidoptera: Tortricidae) larval infestation and injury in northern Greece.

    Science.gov (United States)

    Ifoulis, A A; Savopoulou-Soultani, M

    2006-10-01

    The purpose of this research was to quantify the spatial pattern and develop a sampling program for larvae of Lobesia botrana Denis and Schiffermüller (Lepidoptera: Tortricidae), an important vineyard pest in northern Greece. Taylor's power law and Iwao's patchiness regression were used to model the relationship between the mean and the variance of larval counts. Analysis of covariance was carried out, separately for infestation and injury, with combined second and third generation data, for vine and half-vine sample units. Common regression coefficients were estimated to permit use of the sampling plan over a wide range of conditions. Optimum sample sizes for infestation and injury, at three levels of precision, were developed. An investigation of a multistage sampling plan with a nested analysis of variance showed that if the goal of sampling is focusing on larval infestation, three grape clusters should be sampled in a half-vine; if the goal of sampling is focusing on injury, then two grape clusters per half-vine are recommended.

  7. Multi-stage ranking of emergency technology alternatives for water source pollution accidents using a fuzzy group decision making tool.

    Science.gov (United States)

    Qu, Jianhua; Meng, Xianlin; You, Hong

    2016-06-05

    Due to the increasing number of unexpected water source pollution events, selection of the most appropriate disposal technology for a specific pollution scenario is of crucial importance to the security of urban water supplies. However, the formulation of the optimum option is considerably difficult owing to the substantial uncertainty of such accidents. In this research, a multi-stage technical screening and evaluation tool is proposed to determine the optimal technique scheme, considering the areas of pollutant elimination both in drinking water sources and water treatment plants. In stage 1, a CBR-based group decision tool was developed to screen available technologies for different scenarios. Then, the threat degree caused by the pollution was estimated in stage 2 using a threat evaluation system and was partitioned into four levels. For each threat level, a corresponding set of technique evaluation criteria weights was obtained using Group-G1. To identify the optimization alternatives corresponding to the different threat levels, an extension of TOPSIS, a multi-criteria interval-valued trapezoidal fuzzy decision making technique containing the four arrays of criteria weights, to a group decision environment was investigated in stage 3. The effectiveness of the developed tool was elaborated by two actual thallium-contaminated scenarios associated with different threat levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. The effect of multistage nanovector targeting of VEGFR2 positive tumor endothelia on cell adhesion and local payload accumulation.

    Science.gov (United States)

    Martinez, Jonathan O; Evangelopoulos, Michael; Karun, Vivek; Shegog, Evan; Wang, Joshua A; Boada, Christian; Liu, Xuewu; Ferrari, Mauro; Tasciotti, Ennio

    2014-12-01

    Nanovectors are a viable solution to the formulation of poorly soluble anticancer drugs. Their bioaccumulation in the tumor parenchyma is mainly achieved exploiting the enhanced permeability and retention (EPR) effect of the leaky neovasculature. In this paper we demonstrate that multistage nanovectors (MSV) exhibit rapid tumoritropic homing independent of EPR, relying on particle geometry and surface adhesion. By studying endothelial cells overexpressing vascular endothelial growth factor receptor-2 (VEGFR2), we developed MSV able to preferentially target VEGFR2 expressing tumor-associated vessels. Static and dynamic targeting revealed that MSV conjugated with anti-VEGFR2 antibodies displayed greater than a 4-fold increase in targeting efficiency towards VEGFR2 expressing cells while exhibiting minimal adherence to control cells. Additionally, VEGFR2 conjugation bestowed MSV with a significant increase in breast tumor targeting and in the delivery of a model payload while decreasing their accumulation in the liver. Surface functionalization with an anti-VEGFR2 antibody provided enhanced affinity towards the tumor vascular endothelium, which promoted enhanced adhesion and tumoritropic accumulation of a reporter molecule released by the MSV. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Manmade target extraction based on multistage decision and its application for change detection in polarimetric synthetic aperture radar image

    Science.gov (United States)

    Cong, Runmin; Han, Ping; Li, Chongyi; He, Jiaji; Zhang, Zaiji

    2016-09-01

    Targets of interest are different in various applications in which manmade targets, such as aircraft, ships, and buildings, are given more attention. Manmade target extraction methods using synthetic aperture radar (SAR) images are designed in response to various demands, which include civil uses, business purposes, and military industries. This plays an increasingly vital role in monitoring, military reconnaissance, and precision strikes. Achieving accurate and complete results through traditional methods is becoming more challenging because of the scattered complexity of polarization in polarimetric synthetic aperture radar (PolSAR) image. A multistage decision-based method is proposed composed of power decision, dominant scattering mechanism decision, and reflection symmetry decision. In addition, the theories of polarimetric contrast enhancement, generalized Y decomposition, and maximum eigenvalue ratio are applied to assist the decision. Fully PolSAR data are adopted to evaluate and verify the approach. Experimental results show that the method can achieve an effective result with a lower false alarm rate and clear contours. Finally, on this basis, a universal framework of change detection for manmade targets is presented as an application of our method. Two sets of measured data are also used to evaluate and verify the effectiveness of the change-detection algorithm.

  10. Multistage amphiboles from the Galinge iron skarn deposit in Qiman Tagh, western China: evidence of igneous rocks replacement

    Science.gov (United States)

    Yu, M.; Feng, C.-Y.; Zhu, Y.-F.; Mao, J.-W.; Zhao, Y.-M.; Li, D.-X.

    2017-02-01

    Amphiboles from the Galinge skarn deposit, the largest iron (Fe) polymetallic skarn deposit in the Qiman Tagh metallogenic belt (western China), were formed by multistage fluid-rock interactions. Mineral analysis of the various amphiboles suggest that they were formed by the replacement of mafic to intermediate igneous rocks. The two alteration phases have formed three generations of compositionally distinct amphiboles: Amp-I: Ferro-edenitic hornblende (FE); Amp-II: Deep bluish-green magnesian-hastingsite (MH); Amp-III: Light greenish-beige ferro-actinolite (FA). The Amp-I preserves the primary igneous amphibole composition, and was subsequently replaced by Amp-II. The amphibole Cl content markedly increases from the FE (0.176 - 0.582 wt.%) to the MH (0.894 - 3.161 wt.%), and abruptly drops in the FA (0.017 - 0.039 wt.%). The Cl-rich MH contains the lowest concentration of Si [5.64 - 6.28 atoms per formula unit (apfu)], and the highest (K + Na) values (0.72 - 1.06 apfu) in the amphibole A-site with a high K/(K + Na) of 0.491 to 0.429. Both Mg and Fe contents of the MH and FA vary widely, possibly due to the interactions of magma-derived hydrothermal fluids with the basaltic / andesitic host rocks.

  11. Dynamic solar-powered multi-stage direct contact membrane distillation system: Concept design, modeling and simulation

    KAUST Repository

    Lee, Jung Gil

    2017-04-26

    This paper presents a theoretical analysis of the monthly average daily and hourly performances of a solar-powered multi-stage direct contact membrane distillation (SMDCMD) system with an energy recovery scheme and dynamic operating system. Mid-latitude meteorological data from Busan, Korea is employed, featuring large climate variation over the course of one year. The number of module stages used by the dynamic operating scheme changes dynamically based on the inlet feed temperature of the successive modules, which results in an improvement of the water production and thermal efficiency. The simulations of the SMDCMD system are carried out to investigate the spatial and temporal variations in the feed and permeate temperatures and permeate flux. The monthly average daily water production increases from 0.37m3/day to 0.4m3/day and thermal efficiency increases from 31% to 45% when comparing systems both without and with dynamic operation in December. The water production with respect to collector area ranged from 350m2 to 550m2 and the seawater storage tank volume ranged from 16m3 to 28.8m3, and the solar fraction at various desired feed temperatures from 50°C to 80°C have been investigated in October and December.

  12. A comparative analysis of multi-stage fracture stimulation treatments within the Bakken formation, Kisbey Area, SE Sask

    Energy Technology Data Exchange (ETDEWEB)

    Hassler, G.; Poohkay, P.; Jubinville, L. [Tristar Oil and Gas Ltd., Calgary, AB (Canada)

    2009-07-01

    Multi-stage stimulation treatments used in the Bakken formation were discussed in this presentation. The middle Bakken formation is comprised primarily of dolomitic siltstone with an oil saturation level of between 50 to 70 per cent. Original oil in place is estimated at between 4000 to 5000 mBbls. Porosity ranges between 15 and 5 per cent. Horizontal drilling techniques are used at the formation. This study compared production histories with various fracture treatment variations, wellbore lengths, and orientations. The study examined the impact of total tonnage on production wells of similar length, as well as the impact of increased fracture density on production rates. The aim of the study was to determine optimal well spacing, length and fracture design combinations. A total of 38 wells were studied with a variety of fracture treatments. Data were obtained for flush rates, production rates, and cumulative production rates. The study demonstrated that the range of fracture treatments used at the formation will not influence total fluid production rates over time. It was concluded that improvements in fracture design should focus on maximizing fracture conductivity within the reservoir while maximizing the number of fracture intervals per wellbore. tabs., figs.

  13. Analysis of oilfield produced waters and production chemicals by electrospray ionisation multi-stage mass spectrometry (ESI-MSn).

    Science.gov (United States)

    McCormack, P; Jones, P; Hetheridge, M J; Rowland, S J

    2001-10-01

    Large quantities of diverse polar organic chemicals are routinely discharged from oil production platforms in so-called produced waters. The environmental fate of many of these is unknown since few methods exist for their characterisation. Preliminary investigations into the use of multistage electrospray ionisation ion trap mass spectrometry (ESI-MSn) show its potential for the identification and quantification of compounds in specialty oilfield chemicals (corrosion inhibitors, scale inhibitors, biocides and demulsifiers) and produced waters. Multiple stage mass spectrometry (MSn) with both positive and negative ion detection allows high specificity detection and characterisation of a wide range of polar and charged molecules. For example, linear alkylbenzenesulfonates (LAS), alkyldimethylbenzylammonium compounds, 2-alkyl-1-ethylamine-2-imidazolines, 2-alkyl-1-[N-ethylalkylamide]-2-imidazolines and a di-[alkyldimethylammonium-ethyl]ether were all identified and characterised in commercial formulations and/or North Sea oilfield produced waters. The technique should allow the marine environmental effects and fates of some of these polar compounds to be studied.

  14. Multi-stage open peer review: scientific evaluation integrating the strengths of traditional peer review with the virtues of transparency and self-regulation

    Directory of Open Access Journals (Sweden)

    Ulrich ePöschl

    2012-07-01

    Full Text Available The traditional forms of scientific publishing and peer review do not live up to the demands of efficient communication and quality assurance in today’s highly diverse and rapidly evolving world of science. They need to be advanced and complemented by interactive and transparent forms of review, publication, and discussion that are open to the scientific community and to the public.The advantages of open access, public peer review and interactive discussion can be efficiently and flexibly combined with the strengths of traditional scientific peer review. Since 2001 the benefits and viability of this approach are clearly demonstrated by the highly successful interactive open access journal Atmo¬sphe¬ric Chemistry and Physics (ACP and a growing number of sister journals launched and operated by the European Geosciences Union (EGU and the open access publisher Copernicus.The interactive open access journals are practicing an integrative multi-stage process of publication and peer review combined with interactive public discussion, which effectively resolves the dilemma between rapid scientific exchange and thorough quality assurance. The high efficiency and predictive validity of multi-stage open peer review have been confirmed in a series of dedicated studies by evaluation experts from the social sciences, and the same or similar concepts have recently also been adopted in other disciplines, including the life sciences and economics. Multi-stage open peer review can be flexibly adjusted to the needs and peculiarities of different scientific communities. Due to the flexibility and compatibility with traditional structures of scientific publishing and peer review, the multi-stage open peer review concept enables efficient evolution in scientific communication and quality assurance. It has the potential for swift replacement of hidden peer review as the standard of scientific quality assurance, and it provides a basis for open evaluation in

  15. Evaluation of advanced turbomachinery for underground pumped hydroelectric storage. Part 3. Multistage unregulated pump/turbines for operating heads of 1000 to 1500 m

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, A.A.; Pistner, C.

    1980-08-01

    This is the final report in a series of three on studies of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. All three reports address Francis-type, reversible pump/turbines. The first report covered single-stage regulated units; the second report covered two-stage regulated units; the present report covers multistage unregulated units. Multistage unregulated pump/turbines offer an economically attractive option for heads of 1000 to 1500 m. The feasibility of developing such machines for capacities up to 500 MW and operating heads up to 1500 m has been evaluated. Preliminary designs have been generated for six multistage pump/turbines. The designs are for nominal capacities of 350 and 500 MW and for operating heads of 1000, 1250, and 1500 m. Mechanical, hydraulic, and economic analyses indicate that these machines will behave according to the criteria used to design them and that they can be built at a reasonable cost with no unsolvable problems. Efficiencies of 85.8% and 88.5% in the generating and pumping modes, respectively, can be expected for the 500-MW, 1500-m unit. Performances of the other five machines are at least comparable, and usually better. Over a 1000 to 1500-m head range, specific $/kW costs of the pump/turbines in mid-1978 US dollars vary from 19.0 to 23.1 for the 500-MW machines, and from 21.0 to 24.1 for the 350-MW machines.

  16. A multi-stage curing technique toward improved dimensional infidelity of curve-shaped composites manufactured with vacuum assisted resin transfer molding

    Science.gov (United States)

    Teoh, Kai Jin

    The occurrence of dimensional infidelity during the curing process is detected as curved composites are being released from the mold after full consolidation. On the other hand, the lengthy cure cycle, thermal spiking and non-uniform consolidation in thick composite manufacturing are often strong deterrents to widespread industrial implementation. Therefore, a multi-stage curing technique is implemented and its outcome toward the spring-in phenomenon is investigated in this research. The composite processing technique of stage curing is useful for assessing the effects of thermal spiking, non-uniform consolidation and fiber wrinkling on mechanical integrity for thick composite structures. However, the prediction of spring-in behavior for a multi-stage curing process is still a relatively unexplored area in engineering research. As a result, a compatibility model based on the residual stress that builds up at each curing stage is performed in our study. Since the resin provides a lubricant effect between each curing stage, a partial slipping interface factor w is introduced to our numerical simulation model. The newly developed multi-stage curing model shows good agreement with the experimental results under Vacuum Assisted Resin Transfer Molding (VARTM) process.

  17. Comparing a single-stage geocoding method to a multi-stage geocoding method: how much and where do they disagree?

    Directory of Open Access Journals (Sweden)

    Rice Kenneth

    2007-03-01

    Full Text Available Abstract Background Geocoding methods vary among spatial epidemiology studies. Errors in the geocoding process and differential match rates may reduce study validity. We compared two geocoding methods using 8,157 Washington State addresses. The multi-stage geocoding method implemented by the state health department used a sequence of local and national reference files. The single-stage method used a single national reference file. For each address geocoded by both methods, we measured the distance between the locations assigned by each method. Area-level characteristics were collected from census data, and modeled as predictors of the discordance between geocoded address coordinates. Results The multi-stage method had a higher match rate than the single-stage method: 99% versus 95%. Of 7,686 addresses were geocoded by both methods, 96% were geocoded to the same census tract by both methods and 98% were geocoded to locations within 1 km of each other by the two methods. The distance between geocoded coordinates for the same address was higher in sparsely populated and low poverty areas, and counties with local reference files. Conclusion The multi-stage geocoding method had a higher match rate than the single-stage method. An examination of differences in the location assigned to the same address suggested that study results may be most sensitive to the choice of geocoding method in sparsely populated or low-poverty areas.

  18. Design and Evaluation of Primaquine-Artemisinin Hybrids as a Multistage Antimalarial Strategy▿†

    Science.gov (United States)

    Capela, Rita; Cabal, Ghislain G.; Rosenthal, Philip J.; Gut, Jiri; Mota, Maria M.; Moreira, Rui; Lopes, Francisca; Prudêncio, Miguel

    2011-01-01

    It is widely accepted that the struggle against malaria depends on the development of new strategies to fight infection. The “magic bullet” thought to be necessary to reach eradication should not only provide treatment for all Plasmodium spp. that infect human red blood cells but should also eliminate the replicative and dormant liver forms of the parasite. Moreover, these goals should ideally be achieved by using different mechanisms of action so as to avoid the development of resistance. To that end, two hybrid molecules with covalently linked primaquine and artemisinin moieties were synthesized, and their effectiveness against the liver and blood stages of infection was compared in vitro and in vivo with those of the parent compounds. Both hybrids displayed enhanced in vitro activities, relative to those of the parent compounds, against Plasmodium berghei liver stages. Both compounds were about as potent as artemisinin against cultured Plasmodium falciparum (50% inhibitory concentration [IC50], ∼10 nM). When used to treat a murine P. berghei infection, one of the molecules displayed better efficacy than an equimolar mixture of the parent pharmacophores, leading to improved cure and survival rates. These results reveal a novel approach to the design and evaluation of antimalarials based on the covalent combination of molecules acting on different stages of the parasite life cycle. PMID:21807973

  19. Design and evaluation of primaquine-artemisinin hybrids as a multistage antimalarial strategy.

    Science.gov (United States)

    Capela, Rita; Cabal, Ghislain G; Rosenthal, Philip J; Gut, Jiri; Mota, Maria M; Moreira, Rui; Lopes, Francisca; Prudêncio, Miguel

    2011-10-01

    It is widely accepted that the struggle against malaria depends on the development of new strategies to fight infection. The "magic bullet" thought to be necessary to reach eradication should not only provide treatment for all Plasmodium spp. that infect human red blood cells but should also eliminate the replicative and dormant liver forms of the parasite. Moreover, these goals should ideally be achieved by using different mechanisms of action so as to avoid the development of resistance. To that end, two hybrid molecules with covalently linked primaquine and artemisinin moieties were synthesized, and their effectiveness against the liver and blood stages of infection was compared in vitro and in vivo with those of the parent compounds. Both hybrids displayed enhanced in vitro activities, relative to those of the parent compounds, against Plasmodium berghei liver stages. Both compounds were about as potent as artemisinin against cultured Plasmodium falciparum (50% inhibitory concentration [IC(50)], ∼10 nM). When used to treat a murine P. berghei infection, one of the molecules displayed better efficacy than an equimolar mixture of the parent pharmacophores, leading to improved cure and survival rates. These results reveal a novel approach to the design and evaluation of antimalarials based on the covalent combination of molecules acting on different stages of the parasite life cycle.

  20. Development of PIN and Prostate Adenocarcinoma Cell Lines: A Model System for Multistage Tumor Progression

    Directory of Open Access Journals (Sweden)

    Colin R. Soares

    2002-01-01

    Full Text Available Existing prostate cancer cell lines have been derived from late stages of human prostate cancer. In this paper, we present two cell lines generated from prostatic intraepithelial neoplasia (PIN, the precursor lesion for prostate adenocarcinoma. Pr-111 and Pr-117 were established from PIN lesions that developed in the C3(1/Tag transgenic model of prostate cancer. Pr-111 and Pr-117 cells express simian virus 40 large T antigen (SV40 Tag and are immortalized in culture, distinguishing them from normal prostate cells. The growth rates of these two cell lines are quite different; with Pr-111 cells growing much more slowly (doubling time approximately 40 hours compared to Pr-117 cells (doubling time approximately 22 hours, and also show significantly different growth rates in different media. Both prostate cell lines express cytokeratin and androgen receptor (AR with Pr-111 cells demonstrating androgen-dependent growth and Pr-117 cells exhibiting androgen-responsive growth characteristics. Athymic nude mice injected with Pr-111 cells either do not develop tumors or develop tumors after a long latency period of 14 weeks. Pr-117 cells, however, develop tumors by 3 to 6 weeks, suggesting that Pr-117 cells represent a later stage of tumor progression. These two novel cell lines will be useful for studying early stages of prostate tumor development and androgen responsiveness.

  1. Improvement of a multi-stage model for the modeling of a functionalized nursing bed as support for the sensor-assisted function-alization of furniture in the hospital and care sector

    Directory of Open Access Journals (Sweden)

    Kitzig Andreas

    2017-09-01

    Full Text Available Development of preparation-free functionalized furniture based patient monitoring systems for use in the area of home- or stationary- care is often empirically driven. In particular, functionalization of furniture by means of different sensors is strongly affected by this development methodology. As a result, the systems are often not extensive-ly extendable or cannot be optimized because basic mechanisms are not comprehensible. In order to support development or optimization, a modelling approach is often useful. Thus, using a more comprehensive approach the required sensitivity of the sensors as well as their position in the system can be derived from a simulation model. In order to solve this problem, a multi-stage model was introduced at the BMT conference in 2014 by the authors, which allows the designer to model the entire system. The model has been extended and improved in the meantime and the achieved progress is presented in this work. The presented modelling approach can be divided into three main components. These are the person under supervision, the furniture (in our case a nursing bed and the sensors (force measuring cells which are modelled separately. In this work the main focus will be on improving the modelling of the human movement process and its implementation. Furthermore, the modelling of the sensor behavior in the nursing bed is described in detail with regard to their oscillation behavior and the influence on the model.

  2. Multi-stage melt-rock interaction in the Mt. Maggiore (Corsica, France) ophiolitic peridotites: microstructural and geochemical evidence

    Science.gov (United States)

    Rampone, Elisabetta; Piccardo, Giovanni B.; Hofmann, Albrecht W.

    2008-10-01

    Spinel and plagioclase peridotites from the Mt.Maggiore (Corsica, France) ophiolitic massif record a composite asthenosphere-lithosphere history of partial melting and subsequent multi-stage melt-rock interaction. Cpx-poor spinel lherzolites are consistent with mantle residues after low-degree fractional melting ( F = 5-10%). Opx + spinel symplectites at the rims of orthopyroxene porphyroclasts indicate post-melting lithospheric cooling ( T = 970-1,100°C); this was followed by formation of olivine embayments within pyroxene porphyroclasts by melt-rock interaction. Enrichment in modal olivine (up to 85 wt%) at constant bulk Mg values, and variable absolute REE contents (at constant LREE/HREE) indicate olivine precipitation and pyroxene dissolution during reactive porous melt flow. This stage occurred at spinel-facies depths, after incorporation of the peridotites in the thermal lithosphere. Plagioclase-enriched peridotites show melt impregnation microtextures, like opx + plag intergrowths replacing exsolved cpx porphyroclasts and interstitial gabbronoritic veinlets. This second melt-rock interaction stage caused systematic chemical changes in clinopyroxene (e.g. Ti, REE, Zr, Y increase), related to the concomitant effects of local melt-rock interaction at decreasing melt mass, and crystallization of small (<3%) trapped melt fractions. LREE depletion in minerals of the gabbronoritic veinlets indicates that the impregnating melts were more depleted than normal MORB. Preserved microtextural evidence of previous melt-rock interaction in the impregnated peridotites suggests that they were progressively uplifted in response to lithosphere extension and thinning. Migrating melts were likely produced by mantle upwelling and melting related to extension; they were modified from olivine-saturated to opx-saturated compositions, and caused different styles of melt-rock interaction (reactive spinel harzburgites, vs. impregnated plagioclase peridotites) depending on the

  3. Multistage evolution of UHT granulites from the southernmost part of the Gföhl Nappe, Bohemian Massif, Lower Austria

    Science.gov (United States)

    Schantl, Philip; Hauzenberger, Christoph; Linner, Manfred

    2016-04-01

    A detailed petrological investigation has been undertaken in leucocratic kyanite-garnet bearing and mesocratic orthopyroxene bearing granulites from the Dunkelsteiner Wald, Pöchlarn-Wieselburg and Zöbing granulite bodies from the Moldanubian Zone in the Bohemian Massif (Austria). A combination of textural observations, conventional geothermobarometry, phase equilibrium modelling as well as major and trace element analyses in garnet enables us to confirm a multistage Variscan metamorphic history. Chemically homogenous garnet cores with near constant grossular-rich plateaus are considered to reflect garnet growth during an early HP/UHP metamorphic evolution. Crystallographically oriented rutile exsolutions restricted to those grossular-rich garnet cores point to a subsequent isothermal decompression of the HP/UHP rocks. Overgrowing garnet rims show a pronounced zonation and are interpreted as the result of dehydration melting reactions during an isobaric heating phase which could have taken place near the base of an overthickened continental crust, where the previously deeply subducted rocks were exhumed to. For this HP granulite facies event maximum PT conditions of ~1050 °C and 1.6 GPa have been estimated from leucocratic granulites comprising the peak mineral assemblage quartz, ternary feldspar, garnet, kyanite and rutile. The pronounced zoning of garnet rims indicates that the HP granulite facies event must have been short lived since diffusion in this temperature region is usually sufficient fast to homogenize a zoning pattern in garnet. A retrogressive metamorphic stage is documented in these rocks by the replacement of kyanite to sillimanite and the growth of biotite. This retrograde event took place within the granulite facies but at significantly lower pressures and temperatures with ~0.8 GPa and ~760 °C. This final stage of re-equilibration is thought to be linked with a second exhumation phase into middle crustal levels accompanied by intensive

  4. Multi-Stage 20-m Shuttle Run Fitness Test, Maximal Oxygen Uptake and Velocity at Maximal Oxygen Uptake.

    Science.gov (United States)

    Paradisis, Giorgos P; Zacharogiannis, Elias; Mandila, Dafni; Smirtiotou, Athanasia; Argeitaki, Polyxeni; Cooke, Carlton B

    2014-06-28

    The multi-stage 20-m shuttle run fitness test (20mMSFT) is a popular field test which is widely used to measure aerobic fitness by predicting maximum oxygen uptake (VO2max) and performance. However, the velocity at which VO2max occurs (vVO2max) is a better indicator of performance than VO2max, and can be used to explain inter-individual differences in performance that VO2max cannot. It has been reported as a better predictor for running performance and it can be used to monitor athletes' training for predicting optimal training intensity. This study investigated the validity and suitability of predicting VO2max and vVO2max of adult subjects on the basis of the performance of the 20mMST. Forty eight (25 male and 23 female) physical education students performed, in random order, a laboratory based continuous horizontal treadmill test to determine VO2max, vVO2max and a 20mMST, with an interval of 3 days between each test. The results revealed significant correlations between the number of shuttles in the 20mMSFT and directly determined VO2max (r = 0.87, pVO2max was y = 0.0276x + 27.504, whereas for vVO2max it was y = 0.0937x + 6.890. It can be concluded that the 20mMSFT can accurately predict VO2max and vVO2max and this field test can provide useful information regarding aerobic fitness of adults. The predicted vVO2max can be used in monitoring athletes, especially in determining optimal training intensity.

  5. Multi-Stage 20-m Shuttle Run Fitness Test, Maximal Oxygen Uptake and Velocity at Maximal Oxygen Uptake

    Directory of Open Access Journals (Sweden)

    Paradisis Giorgos P.

    2014-07-01

    Full Text Available The multi-stage 20-m shuttle run fitness test (20mMSFT is a popular field test which is widely used to measure aerobic fitness by predicting maximum oxygen uptake (VO2 max and performance. However, the velocity at which VO 2 max occurs (vVO 2 max is a better indicator of performance than VO 2 max, and can be used to explain inter-individual differences in performance that VO 2 max cannot. It has been reported as a better predictor for running performance and it can be used to monitor athletes’ training for predicting optimal training intensity. This study investigated the validity and suitability of predicting VO2max and vVO2max of adult subjects on the basis of the performance of the 20mMST. Forty eight (25 male and 23 female physical education students performed, in random order, a laboratory based continuous horizontal treadmill test to determine VO2max, vVO 2 max and a 20mMST, with an interval of 3 days between each test. The results revealed significant correlations between the number of shuttles in the 20mMSFT and directly determined VO 2 max (r = 0.87, p<0.05 and vVO 2 max (r = 0.93, p<0.05. The equation for prediction of VO 2 max was y = 0.0276x + 27.504, whereas for vVO 2 max it was y = 0.0937x + 6.890. It can be concluded that the 20mMSFT can accurately predict VO 2 max and vVO 2 max and this field test can provide useful information regarding aerobic fitness of adults. The predicted vVO 2 max can be used in monitoring athletes, especially in determining optimal training intensity.

  6. Analysis of a Multi-component Multi-stage Malaria Vaccine Candidate--Tackling the Cocktail Challenge.

    Directory of Open Access Journals (Sweden)

    Alexander Boes

    Full Text Available Combining key antigens from the different stages of the P. falciparum life cycle in the context of a multi-stage-specific cocktail offers a promising approach towards the development of a malaria vaccine ideally capable of preventing initial infection, the clinical manifestation as well as the transmission of the disease. To investigate the potential of such an approach we combined proteins and domains (11 in total from the pre-erythrocytic, blood and sexual stages of P. falciparum into a cocktail of four different components recombinantly produced in plants. After immunization of rabbits we determined the domain-specific antibody titers as well as component-specific antibody concentrations and correlated them with stage specific in vitro efficacy. Using purified rabbit immune IgG we observed strong inhibition in functional in vitro assays addressing the pre-erythrocytic (up to 80%, blood (up to 90% and sexual parasite stages (100%. Based on the component-specific antibody concentrations we calculated the IC50 values for the pre-erythrocytic stage (17-25 μg/ml, the blood stage (40-60 μg/ml and the sexual stage (1.75 μg/ml. While the results underline the feasibility of a multi-stage vaccine cocktail, the analysis of component-specific efficacy indicates significant differences in IC50 requirements for stage-specific antibody concentrations providing valuable insights into this complex scenario and will thereby improve future approaches towards malaria vaccine cocktail development regarding the selection of suitable antigens and the ratios of components, to fine tune overall and stage-specific efficacy.

  7. Experimental Results of the First Two Stages of an Advanced Transonic Core Compressor Under Isolated and Multi-Stage Conditions

    Science.gov (United States)

    Prahst, Patricia S.; Kulkarni, Sameer; Sohn, Ki H.

    2015-01-01

    NASA's Environmentally Responsible Aviation (ERA) Program calls for investigation of the technology barriers associated with improved fuel efficiency of large gas turbine engines. Under ERA the task for a High Pressure Ratio Core Technology program calls for a higher overall pressure ratio of 60 to 70. This mean that the HPC would have to almost double in pressure ratio and keep its high level of efficiency. The challenge is how to match the corrected mass flow rate of the front two supersonic high reaction and high corrected tip speed stages with a total pressure ratio of 3.5. NASA and GE teamed to address this challenge by using the initial geometry of an advanced GE compressor design to meet the requirements of the first 2 stages of the very high pressure ratio core compressor. The rig was configured to run as a 2 stage machine, with Strut and IGV, Rotor 1 and Stator 1 run as independent tests which were then followed by adding the second stage. The goal is to fully understand the stage performances under isolated and multi-stage conditions and fully understand any differences and provide a detailed aerodynamic data set for CFD validation. Full use was made of steady and unsteady measurement methods to isolate fluid dynamics loss source mechanisms due to interaction and endwalls. The paper will present the description of the compressor test article, its predicted performance and operability, and the experimental results for both the single stage and two stage configurations. We focus the detailed measurements on 97 and 100 of design speed at 3 vane setting angles.

  8. Determining quantitative road safety targets by applying statistical prediction techniques and a multi-stage adjustment procedure.

    Science.gov (United States)

    Wittenberg, P; Sever, K; Knoth, S; Sahin, N; Bondarenko, J

    2013-01-01

    Due to substantial progress made in road safety in the last ten years, the European Union (EU) renewed the ambitious agreement of halving the number of persons killed on the roads within the next decade. In this paper we develop a method that aims at finding an optimal target for each nation, in terms of being as achievable as possible, and with the cumulative EU target being reached. Targets as an important component in road safety policy are given as reduction rate or as absolute number of road traffic deaths. Determination of these quantitative road safety targets (QRST) is done by a top-down approach, formalized in a multi-stage adjustment procedure. Different QRST are derived under consideration of recent research. The paper presents a method to break the national target further down to regional targets in case of the German Federal States. Generalized linear models are fitted to data in the period 1991-2010. Our model selection procedure chooses various models for the EU and solely log-linear models for the German Federal States. If the proposed targets for the EU Member States are attained, the sum of fatalities should not exceed the total value of 15,465 per year by 2020. Both, the mean level and the range of mortality rates within the EU could be lowered from 28-113 in 2010 to 17-41 per million inhabitants in 2020. This study provides an alternative to the determination of safety targets by political commitments only, taking the history of road fatalities trends and population into consideration.

  9. Analysis of a Multi-component Multi-stage Malaria Vaccine Candidate—Tackling the Cocktail Challenge

    Science.gov (United States)

    Voepel, Nadja; Edgue, Gueven; Beiss, Veronique; Kapelski, Stephanie; Fendel, Rolf; Scheuermayer, Matthias; Pradel, Gabriele; Bolscher, Judith M.; Behet, Marije C.; Dechering, Koen J.; Hermsen, Cornelus C.; Sauerwein, Robert W.; Schillberg, Stefan; Reimann, Andreas; Fischer, Rainer

    2015-01-01

    Combining key antigens from the different stages of the P. falciparum life cycle in the context of a multi-stage-specific cocktail offers a promising approach towards the development of a malaria vaccine ideally capable of preventing initial infection, the clinical manifestation as well as the transmission of the disease. To investigate the potential of such an approach we combined proteins and domains (11 in total) from the pre-erythrocytic, blood and sexual stages of P. falciparum into a cocktail of four different components recombinantly produced in plants. After immunization of rabbits we determined the domain-specific antibody titers as well as component-specific antibody concentrations and correlated them with stage specific in vitro efficacy. Using purified rabbit immune IgG we observed strong inhibition in functional in vitro assays addressing the pre-erythrocytic (up to 80%), blood (up to 90%) and sexual parasite stages (100%). Based on the component-specific antibody concentrations we calculated the IC50 values for the pre-erythrocytic stage (17–25 μg/ml), the blood stage (40–60 μg/ml) and the sexual stage (1.75 μg/ml). While the results underline the feasibility of a multi-stage vaccine cocktail, the analysis of component-specific efficacy indicates significant differences in IC50 requirements for stage-specific antibody concentrations providing valuable insights into this complex scenario and will thereby improve future approaches towards malaria vaccine cocktail development regarding the selection of suitable antigens and the ratios of components, to fine tune overall and stage-specific efficacy. PMID:26147206

  10. Analysis of a Multi-component Multi-stage Malaria Vaccine Candidate--Tackling the Cocktail Challenge.

    Science.gov (United States)

    Boes, Alexander; Spiegel, Holger; Voepel, Nadja; Edgue, Gueven; Beiss, Veronique; Kapelski, Stephanie; Fendel, Rolf; Scheuermayer, Matthias; Pradel, Gabriele; Bolscher, Judith M; Behet, Marije C; Dechering, Koen J; Hermsen, Cornelus C; Sauerwein, Robert W; Schillberg, Stefan; Reimann, Andreas; Fischer, Rainer

    2015-01-01

    Combining key antigens from the different stages of the P. falciparum life cycle in the context of a multi-stage-specific cocktail offers a promising approach towards the development of a malaria vaccine ideally capable of preventing initial infection, the clinical manifestation as well as the transmission of the disease. To investigate the potential of such an approach we combined proteins and domains (11 in total) from the pre-erythrocytic, blood and sexual stages of P. falciparum into a cocktail of four different components recombinantly produced in plants. After immunization of rabbits we determined the domain-specific antibody titers as well as component-specific antibody concentrations and correlated them with stage specific in vitro efficacy. Using purified rabbit immune IgG we observed strong inhibition in functional in vitro assays addressing the pre-erythrocytic (up to 80%), blood (up to 90%) and sexual parasite stages (100%). Based on the component-specific antibody concentrations we calculated the IC50 values for the pre-erythrocytic stage (17-25 μg/ml), the blood stage (40-60 μg/ml) and the sexual stage (1.75 μg/ml). While the results underline the feasibility of a multi-stage vaccine cocktail, the analysis of component-specific efficacy indicates significant differences in IC50 requirements for stage-specific antibody concentrations providing valuable insights into this complex scenario and will thereby improve future approaches towards malaria vaccine cocktail development regarding the selection of suitable antigens and the ratios of components, to fine tune overall and stage-specific efficacy.

  11. Testing multistage gain and offset trimming in a single photon counting IC with a charge sharing elimination algorithm

    Science.gov (United States)

    Krzyżanowska, A.; Gryboś, P.; Szczygieł, R.; Maj, P.

    2015-12-01

    Designing a hybrid pixel detector readout electronics operating in a single photon counting mode is a very challenging process, where many main parameters are optimized in parallel (e.g. gain, noise, and threshold dispersion). Additional requirements for a smaller pixel size with extended functionality push designers to use new deep sub-micron technologies. Minimizing the channel size is possible, however, with a decreased pixel size, the charge sharing effect becomes a more important issue. To overcome this problem, we designed an integrated circuit prototype produced in CMOS 40 nm technology, which has an extended functionality of a single pixel. A C8P1 algorithm for the charge sharing effect compensation was implemented. In the algorithm's first stage the charge is rebuilt in a signal rebuilt hub fed by the CSA (charge sensitive amplifier) outputs from four neighbouring pixels. Then, the pixel with the biggest amount of charge is chosen, after a comparison with all the adjacent ones. In order to process the data in such a complicated way, a certain architecture of a single channel was proposed, which allows for: ṡ processing the signal with the possibility of total charge reconstruction (by connecting with the adjacent pixels), ṡ a comparison of certain pixel amplitude to its 8 neighbours, ṡ the extended testability of each block inside the channel to measure CSA gain dispersion, shaper gain dispersion, threshold dispersion (including the simultaneous generation of different pulse amplitudes from different pixels), ṡ trimming all the necessary blocks for proper operation. We present a solution for multistage gain and offset trimming implemented in the IC prototype. It allows for minimization of the total charge extraction errors, minimization of threshold dispersion in the pixel matrix and minimization of errors of comparison of certain pixel pulse amplitudes with all its neighbours. The detailed architecture of a single channel is presented together

  12. Multistage amphiboles from the Galinge iron skarn deposit in Qiman Tagh, western China: evidence of igneous rocks replacement

    Science.gov (United States)

    Yu, M.; Feng, C.-Y.; Zhu, Y.-F.; Mao, J.-W.; Zhao, Y.-M.; Li, D.-X.

    2016-08-01

    Amphiboles from the Galinge skarn deposit, the largest iron (Fe) polymetallic skarn deposit in the Qiman Tagh metallogenic belt (western China), were formed by multistage fluid-rock interactions. Mineral analysis of the various amphiboles suggest that they were formed by the replacement of mafic to intermediate igneous rocks. The two alteration phases have formed three generations of compositionally distinct amphiboles: Amp-I: Ferro-edenitic hornblende (FE); Amp-II: Deep bluish-green magnesian-hastingsite (MH); Amp-III: Light greenish-beige ferro-actinolite (FA). The Amp-I preserves the primary igneous amphibole composition, and was subsequently replaced by Amp-II. The amphibole Cl content markedly increases from the FE (0.176 - 0.582 wt.%) to the MH (0.894 - 3.161 wt.%), and abruptly drops in the FA (0.017 - 0.039 wt.%). The Cl-rich MH contains the lowest concentration of Si [5.64 - 6.28 atoms per formula unit (apfu)], and the highest (K + Na) values (0.72 - 1.06 apfu) in the amphibole A-site with a high K/(K + Na) of 0.491 to 0.429. Both Mg and Fe contents of the MH and FA vary widely, possibly due to the interactions of magma-derived hydrothermal fluids with the basaltic / andesitic host rocks. Formation of the Cl-rich MH may have been associated with the early high-temperature and high-saline hydrothermal fluids, meanwhile the Cl-poor FA may have formed from later low-temperature and low-saline hydrothermal fluids. The MH plays an important role for consuming Cl carried by hydrothermal fluids. The Cl-rich fluids may have mobilized some elements, such as Fe, Al, Mg, Ca and Ti from the host rocks. Considerable amounts of Ti, Al, Mg and Fe were incorporated into the sphene and Fe-Ti oxides that coexist with the MH.

  13. Optimizing for Large Planar Fractures in Multistage Horizontal Wells in Enhanced Geothermal Systems Using a Coupled Fluid and Geomechanics Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiexiaomen; Tutuncu, Azra; Eustes, Alfred; Augustine, Chad

    2017-05-01

    Enhanced Geothermal Systems (EGS) could potentially use technological advancements in coupled implementation of horizontal drilling and multistage hydraulic fracturing techniques in tight oil and shale gas reservoirs along with improvements in reservoir simulation techniques to design and create EGS reservoirs. In this study, a commercial hydraulic fracture simulation package, Mangrove by Schlumberger, was used in an EGS model with largely distributed pre-existing natural fractures to model fracture propagation during the creation of a complex fracture network. The main goal of this study is to investigate optimum treatment parameters in creating multiple large, planar fractures to hydraulically connect a horizontal injection well and a horizontal production well that are 10,000 ft. deep and spaced 500 ft. apart from each other. A matrix of simulations for this study was carried out to determine the influence of reservoir and treatment parameters on preventing (or aiding) the creation of large planar fractures. The reservoir parameters investigated during the matrix simulations include the in-situ stress state and properties of the natural fracture set such as the primary and secondary fracture orientation, average fracture length, and average fracture spacing. The treatment parameters investigated during the simulations were fluid viscosity, proppant concentration, pump rate, and pump volume. A final simulation with optimized design parameters was performed. The optimized design simulation indicated that high fluid viscosity, high proppant concentration, large pump volume and pump rate tend to minimize the complexity of the created fracture network. Additionally, a reservoir with 'friendly' formation characteristics such as large stress anisotropy, natural fractures set parallel to the maximum horizontal principal stress (SHmax), and large natural fracture spacing also promote the creation of large planar fractures while minimizing fracture complexity.

  14. THE MULTISTAGE METHODS FOR SOLVING SYMMETRIC POSITIVE DEFINITE TOEPLITZ SYSTEMS%对称正定Toeplitz方程组的多级迭代求解

    Institute of Scientific and Technical Information of China (English)

    刘仲云; 刘成志; 张育林

    2012-01-01

    The two-stage iterative methods are also called inner/outer iterative methods. The multistage iteration is nested by several two-stage iterations. Those methods are especially suitable for parallel computation, and can be viewed as extensions of classical iterative methods or as preconditioners for conjugate gradient methods. In this paper, we consider the multistage iterative methods for solving symmetric positive definite Toeplitz systems. Based on the Toeplitz structure, we first construct a multistage block Jacobi splitting, then we prove that the corresponding splitting at each level is P-regular, and show that the resulting method is convergent when the number of iteration at each level is even. At the end, we give some numerical examples to illustrate the effectiveness of our methods.%二级迭代法亦称内外迭代法.多级迭代法由多个二级迭代嵌套而成.这些方法特别适合于并行计算,同时可以理解为古典迭代法的延伸或共轭梯度法的预处理子.本文讨论了对称正定Toeplitz线性方程组多级迭代法.首先,基于Toeplitz矩阵的结构,我们给出了多级块Jacobi分裂,然后证明了每一级分裂均为P-正则分裂,并证明了当每一级内迭代次数均为偶数时,迭代法的收敛性.最后通过数值实例验证了此方法的有效性.

  15. Simulation of multi-stage nonlinear bone remodeling induced by fixed partial dentures of different configurations: a comparative clinical and numerical study.

    Science.gov (United States)

    Liao, Zhipeng; Yoda, Nobuhiro; Chen, Junning; Zheng, Keke; Sasaki, Keiichi; Swain, Michael V; Li, Qing

    2017-04-01

    This paper aimed to develop a clinically validated bone remodeling algorithm by integrating bone's dynamic properties in a multi-stage fashion based on a four-year clinical follow-up of implant treatment. The configurational effects of fixed partial dentures (FPDs) were explored using a multi-stage remodeling rule. Three-dimensional real-time occlusal loads during maximum voluntary clenching were measured with a piezoelectric force transducer and were incorporated into a computerized tomography-based finite element mandibular model. Virtual X-ray images were generated based on simulation and statistically correlated with clinical data using linear regressions. The strain energy density-driven remodeling parameters were regulated over the time frame considered. A linear single-stage bone remodeling algorithm, with a single set of constant remodeling parameters, was found to poorly fit with clinical data through linear regression (low [Formula: see text] and R), whereas a time-dependent multi-stage algorithm better simulated the remodeling process (high [Formula: see text] and R) against the clinical results. The three-implant-supported and distally cantilevered FPDs presented noticeable and continuous bone apposition, mainly adjacent to the cervical and apical regions. The bridged and mesially cantilevered FPDs showed bone resorption or no visible bone formation in some areas. Time-dependent variation of bone remodeling parameters is recommended to better correlate remodeling simulation with clinical follow-up. The position of FPD pontics plays a critical role in mechanobiological functionality and bone remodeling. Caution should be exercised when selecting the cantilever FPD due to the risk of overloading bone resorption.

  16. A multi-stage heuristic algorithm for matching problem in the modified miniload automated storage and retrieval system of e-commerce

    Science.gov (United States)

    Wang, Wenrui; Wu, Yaohua; Wu, Yingying

    2016-05-01

    E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center.

  17. 小孔径多级孔板组件节流效应仿真%Simulation for throttling effect of small aperture multistage orifice units

    Institute of Scientific and Technical Information of China (English)

    刘万龙; 梁国柱; 徐铭; 张化照

    2011-01-01

    对小孔径多级孔板组件(简称多级孔板)节流效应进行仿真研究,发现这类仿真对初场要求非常严格,初场不合理很容易产生伪平衡问题,通过迭代计算寻找合理初场的方法解决了该问题.同时对孔径0.1 mm、孔径比0.025的多级孔板进行了数值仿真,仿真结果表明孔板数是影响多级孔板流量系数的主要因素.根据仿真数据给出多级孔板流量系数拟合公式,可以应用于工程设计计算.%Throttling effect of small aperture multistage orifice units was studied through simulation method. It was found that strict initial flow field was needed in this kind of simulation, and the simulation would be dummy-balanced with irrational initial flow field. This problem was solved by iterative finding proper initial flow field. The multistage orifice units with 0.1 mm aperture and 0.025 aperture ratio were simulated. The simulation result shows that the number of the orifices is the major factor which influences the flow coefficients of the multistage orifice units. Fitted formulae for the flow coefficients were given depending on the simulation results. The fitted formulae can be applied to actual engineering design calculation.

  18. EOQ zone analysis based on multi-stage supply chain%基于多阶供应链的EOQ zone分析

    Institute of Scientific and Technical Information of China (English)

    张瑞夫

    2013-01-01

    This paper aimed at economic lot size problem for multi-stage supply chain study and made the total cost curve sensitivity greatly reduced in the total cost curve flat area in the EOQ model,but the scope of this area and how to use the flat suitability in multi-stage supply chain were the main considerations elements in making bulk supply chain decisions.Meanwhile,this paper divided the flat areas into two parts,i.e.the left and right.By contrast and dynamic analysis of multi-stage supply chain,found the best solution to resolving the problem of large-scale supply chain.%针对多阶供应链中经济批量问题展开研究,在EOQ模型中存在一个总成本曲线扁平区域,使得总成本曲线的敏感度大为降低,但这个区域的范围和扁平适用度如何在多阶供应链中得以运用,是我们进行供应链批量决策的主要考量要素.同时我们进一步把扁平区域分成左右两个部分,通过对比及对多阶供应链的动态分析,找到解决大规模供应链问题的最佳解.

  19. A Multi-Stage Ultra-Endurance Run over 1,200 KM Leads to a Continuous Accumulation of Total Body Water

    Science.gov (United States)

    Knechtle, Beat; Duff, Brida; Schulze, Ingo; Kohler, Götz

    2008-01-01

    We determined whether ultra-runners in a multi-stage ultra- endurance run lose body mass, fat mass, skeletal muscle mass or total body water in a descriptive field study at the ‘Deutschlandlauf’ 2007 a 1,200 km run within 17 consecutive days with 10 male non-professional Caucasian ultra-runners (mean ± SD, 43.8 ± 6.2 years, 73.8 ± 6.0 kg body mass, 1.77 ± 0.05 m body height, BMI 23.3 ± 1.8 kg·m-2). Body mass, fat mass, skeletal muscle mass, lean body mass and percent total body water were determined using bioelectrical impedance analysis and the anthropometric method before the race and after each stage. In addition, urinary specific gravity was measured in order to quantify hydration status. Fat mass (bioelectrical impedance analysis) decreased by 3.9 kg (p < 0.05), skeletal muscle mass (anthropometric method) decreased by 2.0 kg (p < 0.05) whereas percent total body water increased by 6.1 % (p < 0.05) by the end of the race. Ultra-runners in a multi-stage ultra-endurance event over 1,200 km, with 17 consecutive stages, showed a cumulative increase in percent total body water, a decrease in skeletal muscle mass and a decrease in fat mass, depending upon the method used. We presume that the eccentric component of running leads to damage of skeletal muscle, leading to rhabdomyolysis, with impaired renal function. Key pointsUltra-runners in a multi-stage ultra-endurance run over 1,200 km in 17 consecutive stages suffered a decrease in fat mass, skeletal muscle mass and an increase in total body water, whereas overall body mass showed no change. PMID:24149903

  20. Comparison between 30-15 Intermittent Fitness Test and Multistage Field Test on physiological responses in wheelchair basketball players

    Directory of Open Access Journals (Sweden)

    Thierry eWeissland

    2015-12-01

    Full Text Available The intermittent nature of wheelchair court sports suggests using a similar protocol to assess repeated shuttles and recovery abilities. This study aimed to compare performances, physiological responses and perceived rating exertion obtained from the continuous multistage field test (MFT and the 30-15 intermittent field test (30-15IFT. Eighteen trained wheelchair basketball players (WBP (WBP: 32.0±5.7y, IWBF classification: 2.9±1.1points performed both incremental field tests in randomized order. Time to exhaustion, maximal rolling velocity (MRV, VO2peak and the peak values of minute ventilation (VEpeak, respiratory frequency (RF and heart rate (HRpeak were measured throughout both tests; peak and net blood lactate (Δ [Lact-] = peak–rest values and perceived rating exertion (RPE values at the end of each exercise. No significant difference in VO2peak, VEpeak and RF was found between both tests. 30-15IFT was shorter (12.4±2.4 vs. 14.9±5.1min, P<0.05 but induced higher values of MRV and Δ [Lact-] compared to MFT (14.2±1.8 vs. 11.1±1.9km•h-1 and 8.3±4.2 vs. 6.9±3.3mmol•L-1, P<0.05. However, HRpeak and RPE values were higher during MFT than 30-15IFT (172.8±14.0 vs. 166.8±13.8bpm and 15.3±3.8 vs.13.8±3.5, respectively, P<0.05. The intermittent shuttles intercepted with rest period occurred during the 30-15IFT could explain a greater anaerobic solicitation. The higher HR and overall RPE values measured at the end of MFT could be explained by its longer duration and a continuous load stress compared to 30-15IFT. In conclusion, 30-15IFT has some advantages over MFT for assess in addition physical fitness and technical performance in WBP.

  1. Multistage late Cenozoic evolution of the Amargosa River drainage, southwestern Nevada and eastern California Society of America. All rights reserved

    Science.gov (United States)

    Menges, C.M.

    2008-01-01

    Stratigraphic and geomorphic analyses reveal that the regional drainage basin of the modern Amargosa River formed via multistage linkage of formerly isolated basins in a diachronous series of integration events between late Miocene and latest Pleistocene-Holocene time. The 275-km-long Amargosa River system drains generally southward across a large (15,540 km 2) watershed in southwestern Nevada and eastern California to its terminus in central Death Valley. This drainage basin is divided into four major subbasins along the main channel and several minor subbasins on tributaries; these subbasins contain features, including central valley lowlands surrounded by highlands that form external divides or internal paleodivides, which suggest relict individual physiographic-hydrologic basins. From north to south, the main subbasins along the main channel are: (1) an upper headwaters subbasin, which is deeply incised into mostly Tertiary sediments and volcanic rocks; (2) an unincised low-gradient section within the Amargosa Desert; (3) a mostly incised section centered on Tecopa Valley and tributary drainages; and (4) a west- to northwest-oriented mostly aggrading lower section along the axis of southern Death Valley. Adjoining subbasins are hydro-logically linked by interconnecting narrows or canyon reaches that are variably incised into formerly continuous paleodivides. The most important linkages along the main channel include: (1) the Beatty narrows, which developed across a Tertiary bedrock paleodivide between the upper and Amargosa Desert subbasins during a latest Miocene-early Pliocene to middle Pleistocene interval (ca. 4-0.5 Ma); (2) the Eagle Mountain narrows, which cut into a mostly alluvial paleodivide between the Amar-gosa Desert and Tecopa subbasins in middle to late Pleistocene (ca. 150-100 ka) time; and (3) the Amargosa Canyon, which formed in late middle Pleistocene (ca. 200140 ka) time through a breached, actively uplifting paleodivide between the Tecopa

  2. Triassic to Cenozoic multi-stage intra-plate deformation focused near the Bogd Fault system, Gobi Altai, Mongolia

    Institute of Scientific and Technical Information of China (English)

    Douwe J.J. van Hinsbergen; Dickson Cunningham; Gijsbert B. Straathof; Morgan Ganerød; Bart W.H. Hendriks; Arjan H. Dijkstra

    2015-01-01

    The Gobi Altai region of southern Mongolia has been in the Eurasian plate interior since the mid-Mesozoic, yet has experienced episodic phases of deformation since that time. In this paper, we docu-ment field evidence to characterize and date the intra-plate tectonic history of the Gobi Altai region from the Triassic to the present. To this end, we provide detailed mapping of the structure and stratigraphy of the eastern flanks of Mt. Ih Bogd that contains the widest variety of rock-time units in the area. We carry out geochronological analysis of basaltic lavas and basement granite in the area. We demonstrate that a crystalline basement with a 502 ? 8 Ma granitoid (U/Pb) underwent two phases of basin formation in the Mesozoic, which we date with new 40Ar/39Ar lava ages of 218.5 ? 1.5, 123.2 ? 0.7 and 124.8 ? 1.2 Ma, respectively. Both phases are linked to deposition of fluvio-lacustrine sediments and trap-like basaltic volcanics, with cumulative thicknesses of 1000e1500 m. Both basins were likely north-facing half-gra-bens that developed under wNeS extension, but were subsequently overthrusted by Paleozoic and older crystalline basement during a less well constrained, but likely mid-Cretaceous phase of NeS shortening and basin inversion. Our results are consistent with recent seismic imaging of rift basins w100 km to the NE of the study area where a similar history was reconstructed. The multiple phases of intra-plate deformation appear to have parallel structural trends, most likely due to reactivated Paleozoic base-ment structures created during the original terrane amalgamation of the Central Asian Orogenic Belt continental crust. This strong basement heterogeneity may predispose it to reactivation, and make it sensitive to changes in the overall stress field of the Eurasian plate driven by forces at its margins and base. Detailed study of Mongolia’s multi-stage tectonic history may thus provide a key proxy for the long-term dynamics of the Eurasian plate. In

  3. Spent-beam refocusing analysis and multistage depressed collector design for a 75-W, 59- to 64-GHz coupled-cavity traveling-wave tube

    Science.gov (United States)

    Wilson, Jeffrey D.; Ramins, Peter; Force, Dale A.

    1990-01-01

    A computational design technique for coupled-cavity tubes (TWTs) equipped with spent-beam refocusers (SBRs) and multistage depressed collectors (MDCs) is described. A large-signal multidimensional computer program was used to analyze the TWT-SBR performance and to generate the spent-beam models used for MDC design. The results of a design involving a 75-W, 59 to 64 GHz TWT are presented. The SBR and MDC designs are shown, and the computed TWT, SBR, and MDC performances are described. Collector efficiencies in excess of 94 percent led to projected overall TWT efficiencies in the 40-percent range.

  4. Multi-Stage Open Peer Review: Scientific Evaluation Integrating the Strengths of Traditional Peer Review with the Virtues of Transparency and Self-Regulation

    Science.gov (United States)

    Pöschl, Ulrich

    2012-01-01

    The traditional forms of scientific publishing and peer review do not live up to all demands of efficient communication and quality assurance in today’s highly diverse and rapidly evolving world of science. They need to be advanced and complemented by interactive and transparent forms of review, publication, and discussion that are open to the scientific community and to the public. The advantages of open access, public peer review, and interactive discussion can be efficiently and flexibly combined with the strengths of traditional scientific peer review. Since 2001 the benefits and viability of this approach are clearly demonstrated by the highly successful interactive open access journal Atmospheric Chemistry and Physics (ACP, www.atmos-chem-phys.net) and a growing number of sister journals launched and operated by the European Geosciences Union (EGU, www.egu.eu) and the open access publisher Copernicus (www.copernicus.org). The interactive open access journals are practicing an integrative multi-stage process of publication and peer review combined with interactive public discussion, which effectively resolves the dilemma between rapid scientific exchange and thorough quality assurance. Key features and achievements of this approach are: top quality and impact, efficient self-regulation and low rejection rates, high attractivity and rapid growth, low costs, and financial sustainability. In fact, ACP and the EGU interactive open access sister journals are by most if not all standards more successful than comparable scientific journals with traditional or alternative forms of peer review (editorial statistics, publication statistics, citation statistics, economic costs, and sustainability). The high efficiency and predictive validity of multi-stage open peer review have been confirmed in a series of dedicated studies by evaluation experts from the social sciences, and the same or similar concepts have recently also been adopted in other disciplines, including

  5. Dimensioning of 10 Gbit/s all-optical packet switched networks based on optical label swapping routers with multistage 2R regeneration.

    Science.gov (United States)

    Puerto, G; Ortega, B; Manzanedo, M D; Martínez, A; Pastor, D; Capmany, J; Kovacs, G

    2006-10-30

    This paper describes both the experimental and theoretical investigations on the cascadability of all-optical routers in optical label swapping networks incorporating a multistage wavelength conversion with 2R regeneration. A full description of a novel experimental setup allows the packet by packet measurement up to 16 hops with 10 Gb/s payload showing 1 dB penalty with 10(-12) bit error rate. Similarly, the simulations on the system allow a prediction on the cascadability of the router up to 64 hops.

  6. The method used for justification of engineering solutions for multistage plate-type mufflers attached to gas-air ducts of thermal power plants

    Science.gov (United States)

    Tupov, V. B.

    2013-08-01

    This paper describes technical and economic problems associated with the selection of designs of mufflers attached to gas-air ducts of thermal power plants. A method is suggested that makes it possible to determine the dimensions of each stage of plate-type mufflers on the basis of achieving the lowest total discounted costs in order to provide the required acoustical performance at a permissible aerodynamic resistance of a muffler. The condition of the lowest total discounted costs for a multistage muffler, which is valid for different types of mufflers, has been obtained.

  7. Synthetic TLR4 agonists enhance functional antibodies and CD4+ T-cell responses against the Plasmodium falciparum GMZ2.6C multi-stage vaccine antigen

    DEFF Research Database (Denmark)

    Baldwin, Susan L; Roeffen, Will; Singh, Susheel K;

    2016-01-01

    of the sexual-stage protein Pfs48/45-6C genetically fused to GMZ2, an asexual vaccine antigen in advanced clinical development. To select the most suitable vaccine formulation for downstream clinical studies, GMZ2.6C was tested with various immune modulators in different adjuvant formulations (stable emulsions......A subunit vaccine targeting both transmission and pathogenic asexual blood stages of Plasmodium falciparum, i.e., a multi-stage vaccine, could be a powerful tool to combat malaria. Here, we report production and characterization of the recombinant protein GMZ2.6C, which contains a fragment...

  8. Modifications of ORNL's computer programs MSF-21 and VTE-21 for the evaluation and rapid optimization of multistage flash and vertical tube evaporators

    Energy Technology Data Exchange (ETDEWEB)

    Glueckstern, P.; Wilson, J.V.; Reed, S.A.

    1976-06-01

    Design and cost modifications were made to ORNL's Computer Programs MSF-21 and VTE-21 originally developed for the rapid calculation and design optimization of multistage flash (MSF) and multieffect vertical tube evaporator (VTE) desalination plants. The modifications include additional design options to make possible the evaluation of desalting plants based on current technology (the original programs were based on conceptual designs applying advanced and not yet proven technological developments and design features) and new materials and equipment costs updated to mid-1975.

  9. Multi-stage open peer review: scientific evaluation integrating the strengths of traditional peer review with the virtues of transparency and self-regulation.

    Science.gov (United States)

    Pöschl, Ulrich

    2012-01-01

    The traditional forms of scientific publishing and peer review do not live up to all demands of efficient communication and quality assurance in today's highly diverse and rapidly evolving world of science. They need to be advanced and complemented by interactive and transparent forms of review, publication, and discussion that are open to the scientific community and to the public. The advantages of open access, public peer review, and interactive discussion can be efficiently and flexibly combined with the strengths of traditional scientific peer review. Since 2001 the benefits and viability of this approach are clearly demonstrated by the highly successful interactive open access journal Atmospheric Chemistry and Physics (ACP, www.atmos-chem-phys.net) and a growing number of sister journals launched and operated by the European Geosciences Union (EGU, www.egu.eu) and the open access publisher Copernicus (www.copernicus.org). The interactive open access journals are practicing an integrative multi-stage process of publication and peer review combined with interactive public discussion, which effectively resolves the dilemma between rapid scientific exchange and thorough quality assurance. Key features and achievements of this approach are: top quality and impact, efficient self-regulation and low rejection rates, high attractivity and rapid growth, low costs, and financial sustainability. In fact, ACP and the EGU interactive open access sister journals are by most if not all standards more successful than comparable scientific journals with traditional or alternative forms of peer review (editorial statistics, publication statistics, citation statistics, economic costs, and sustainability). The high efficiency and predictive validity of multi-stage open peer review have been confirmed in a series of dedicated studies by evaluation experts from the social sciences, and the same or similar concepts have recently also been adopted in other disciplines, including the

  10. Induced pluripotent stem cells (iPSCs) derived from a symptomatic carrier of a S305I mutation in the microtubule-associated protein tau (MAPT)-gene causing frontotemporal dementia

    DEFF Research Database (Denmark)

    Nimsanor, Natakarn; Jørring, Ida; Rasmussen, Mikkel A.

    2016-01-01

    Frontotemporal dementia with parkinsonism linked to chromosome 17q21.2 (FTDP-17) is an autosomal-dominant neurodegenerative disorder. Mutations in the gene coding the microtubule-associated protein tau (MAPT) can cause FTDP-17 but the underlying mechanisms of the disease are still unknown. Induce...... pluripotent stem cells (iPSCs) hold great promise to model FTDP-17 as such cells can be differentiated in vitro to the required neuronal cell type. Here, we report the generation of iPSCs from a 44-year-old symptomatic woman carrying a S305I mutation in the MAPT-gene....

  11. Induced pluripotent stem cells (iPSCs) derived from af pre-symptomatic carrier of a R406W mutation in microtubule-associated protein tau (MAPT) causing frontotemporal dementia

    DEFF Research Database (Denmark)

    Rasmussen, Mikkel A.; Hjermind, Lena Elisabeth; Hasholt, Lis Frydenreich

    2016-01-01

    Skin fibroblasts were obtained from a 28-year-old pre-symptomatic woman carrying a R406W mutation in microtubule-associated protein tau (MAPT), known to cause frontotemporal dementia. Induced pluripotent stem cell (iPSCs) were established by electroporation with episomal plasmids containing hOCT4...

  12. Effect of cooling rate after hot rolling and of multistage strain aging on the drawability of low-carbon-steel wire rod

    Science.gov (United States)

    Taheri, A. Karimi; Maccagno, T. M.; Jonas, J. J.

    1995-05-01

    Tensile testing was used to simulate the multistage strain aging occurring in low-C steel during the relatively short intervals between dies in a multiple-die wire-drawing machine. The effects were examined of three simulated post-hot-rolling cooling rates and three thermal treatments on the strain-aging susceptibility of a high- and a low-N steel. This was measured by applying a 6 pct tensile strain, followed by aging at either 65° or 100 °C for 20 seconds, and then pulling the specimen to failure at room temperature. Increases in flow stress and decreases in the elongation to fracture both indicated high susceptibility to strain aging. It was found that the nitrogen content, the cooling rate from the hot-rolling temperature to about 300 °C, as well as the cooling rate below 300 °C, all have dramatic effects on the strain-aging behavior. Moreover, multistage strain aging is more severe than single-stage strain aging. The implications of these observations on increasing the drawability of low-carbon-steel wire are discussed.

  13. Kinetics of the pyrolysis of arundo, sawdust, corn stover and switch grass biomass by thermogravimetric analysis using a multi-stage model.

    Science.gov (United States)

    Biney, Paul O; Gyamerah, Michael; Shen, Jiacheng; Menezes, Bruna

    2015-03-01

    A new multi-stage kinetic model has been developed for TGA pyrolysis of arundo, corn stover, sawdust and switch grass that accounts for the initial biomass weight (W0). The biomass were decomposed in a nitrogen atmosphere from 23°C to 900°C in a TGA at a single 20°C/min ramp rate in contrast with the isoconversion technique. The decomposition was divided into multiple stages based on the absolute local minimum values of conversion derivative, (dx/dT), obtained from DTG curves. This resulted in three decomposition stages for arundo, corn stover and sawdust and four stages for switch grass. A linearized multi-stage model was applied to the TGA data for each stage to determine the pre-exponential factor, activation energy, and reaction order. The activation energies ranged from 54.7 to 60.9 kJ/mol, 62.9 to 108.7 kJ/mol, and 18.4 to 257.9 kJ/mol for the first, second and the third decomposition stages respectively.

  14. Selection of the optimal completion of horizontal wells with multi-stage hydraulic fracturing of the low-permeable formation, field C

    Science.gov (United States)

    Bozoev, A. M.; Demidova, E. A.

    2016-03-01

    At the moment, many fields of Western Siberia are in the later stages of development. In this regard, the multilayer fields are actually involved in the development of hard to recover reserves by conducting well interventions. However, most of these assets may not to be economical profitable without application of horizontal drilling and multi-stage hydraulic fracturing treatment. Moreover, location of frac ports in relative to each other, number of stages, volume of proppant per one stage are the main issues due to the fact that the interference effect could lead to the loss of oil production. The optimal arrangement of horizontal wells with multi-stage hydraulic fracture was defined in this paper. Several analytical approaches have been used to predict the started oil flow rate and chose the most appropriate for field C reservoir J1. However, none of the analytical equations could not take into account the interference effect and determine the optimum number of fractures. Therefore, the simulation modelling was used. Finally, the universal equation is derived for this field C, the reservoir J1. This tool could be used to predict the flow rate of the horizontal well with hydraulic fracturing treatment on the qualitative level without simulation model.

  15. Pressure Transient Analysis and Flux Distribution for Multistage Fractured Horizontal Wells in Triple-Porosity Reservoir Media with Consideration of Stress-Sensitivity Effect

    Directory of Open Access Journals (Sweden)

    Jingjing Guo

    2015-01-01

    Full Text Available Triple-porosity model is usually adopted to describe reservoirs with multiscaled pore spaces, including matrix pores, natural fractures, and vugs. Multiple fractures created by hydraulic fracturing can effectively improve the connectivity between existing natural fractures and thus increase well deliverability. However, little work has been done on pressure transient behavior of multistage fractured horizontal wells in triple-porosity reservoirs. Based on source/sink function method, this paper presents a triple-porosity model to investigate the transient pressure dynamics and flux distribution for multistage fractured horizontal wells in fractured-vuggy reservoirs with consideration of stress-dependent natural fracture permeability. The model is semianalytically solved by discretizing hydraulic fractures and Pedrosa’s transformation, perturbation theory, and integration transformation method. Type curves of transient pressure dynamics are generated, and flux distribution among hydraulic fractures for a fractured horizontal well with constant production rate is also discussed. Parametric study shows that major influential parameters on transient pressure responses are parameters pertinent to reservoir properties, interporosity mass transfer, and hydraulic fractures. Analysis of flux distribution indicates that flux density gradually increases from the horizontal wellbore to fracture tips, and the flux contribution of outermost fractures is higher than that of inner fractures. The model can also be extended to optimize hydraulic fracture parameters.

  16. An analytic-geometric model of the effect of spherically distributed injection errors for Galileo and Ulysses spacecraft - The multi-stage problem

    Science.gov (United States)

    Longuski, James M.; Mcronald, Angus D.

    1988-01-01

    In previous work the problem of injecting the Galileo and Ulysses spacecraft from low earth orbit into their respective interplanetary trajectories has been discussed for the single stage (Centaur) vehicle. The central issue, in the event of spherically distributed injection errors, is what happens to the vehicle? The difficulties addressed in this paper involve the multi-stage problem since both Galileo and Ulysses will be utilizing the two-stage IUS system. Ulysses will also include a third stage: the PAM-S. The solution is expressed in terms of probabilities for total percentage of escape, orbit decay and reentry trajectories. Analytic solutions are found for Hill's Equations of Relative Motion (more recently called Clohessy-Wiltshire Equations) for multi-stage injections. These solutions are interpreted geometrically on the injection sphere. The analytic-geometric models compare well with numerical solutions, provide insight into the behavior of trajectories mapped on the injection sphere and simplify the numerical two-dimensional search for trajectory families.

  17. Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system

    Science.gov (United States)

    Azizi, Mohammad Ali; Brouwer, Jacob

    2017-10-01

    A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design. The multi-stage radial design of the compressor enhances the ability of the compressor to maintain air flow rate during transient step-load changes. These transient step-load changes are exhibited in many potential applications for SOFC/GT systems. The compressor provides sustained air flow rate during the mild stall/surge event that occurs due to the transient step-load change that is applied, indicating that this type of compressor is well-suited for this hybrid application.

  18. RGO/AuNR/HA-5FU nanocomposite with multi-stage release behavior and efficient antitumor activity for synergistic therapy.

    Science.gov (United States)

    Yang, Ying; Wang, Yunlong; Zhu, Manzhou; Chen, Yan; Xiao, Yazhong; Shen, Yuhua; Xie, Anjian

    2017-03-16

    A reduced graphene oxide (RGO)/gold nanorod (AuNR)/hydroxyapatite (HA) nanocomposite was designed and successfully synthesized for the first time. An anticancer drug, 5-fluorouracil (5FU), was chosen as a model drug to be loaded in RGO/AuNR/HA. The fabricated RGO/AuNR/HA-5FU showed robust, selective targeting and penetrating efficiency against HeLa cells due to the good compatibility and nontoxicity of HA, and showed excellent synergetic antitumor effects through combined chemotherapy (CT) by 5FU and photothermal therapy (PTT) by both RGO and AuNRs under near-infrared (NIR) laser irradiation. More importantly, this synergistic dual therapy based on RGO/AuNR/HA can also minimize side effects in normal cells and exhibits greater antitumor activity because of a multi-stage drug release ability triggered by the pH sensitivity of HA in the first stage and the combined photothermal conversion capabilities of RGO and AuNRs by means of the NIR laser irradiation in the second stage. This study suggests that the novel RGO/AuNR/HA multi-stage drug delivery system may represent a promising potential application of multifunctional composite materials in the biomedical field.

  19. Sustainable multistage process for enhanced productivity of bioplastics from waste remediation through aerobic dynamic feeding strategy: Process integration for up-scaling.

    Science.gov (United States)

    Amulya, K; Jukuri, Srinivas; Venkata Mohan, S

    2015-01-01

    Polyhydroxyalkanoates (PHA) production was evaluated in a multistage operation using food waste as a renewable feedstock. The first step involved the production of bio-hydrogen (bio-H2) via acidogenic fermentation. Volatile fatty acid (VFA) rich effluent from bio-H2 reactor was subsequently used for PHA production, which was carried out in two stages, Stage II (culture enrichment) and Stage III (PHA production). PHA-storing microorganisms were enriched in a sequencing batch reactor (SBR), operated at two different cycle lengths (CL-24; CL-12). Higher polymer recovery as well as VFA removal was achieved in CL-12 operation both in Stage II (16.3% dry cell weight (DCW); VFA removal, 84%) and Stage III (23.7% DCW; VFA removal, 88%). The PHA obtained was a co-polymer [P(3HB-co-3HV)] of PHB and PHV. The results obtained indicate that this integrated multistage process offers new opportunities to further leverage large scale PHA production with simultaneous waste remediation in the framework of biorefinery.

  20. Stemcell Information: SKIP000911 [SKIP Stemcell Database[Archive

    Lifescience Database Archive (English)

    Full Text Available ... 45 40-49 Female ... Yes No iPSCs derived from Alexander's disease patients. アレキサンダー病患者由来iPS細胞 human ES-li...16-0337-0 Modeling Alexander disease with patient iPSCs reveals cellular and mole