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Sample records for two-stage design procedures

  1. On Two-stage Seamless Adaptive Design in Clinical Trials

    Directory of Open Access Journals (Sweden)

    Shein-Chung Chow

    2008-12-01

    Full Text Available In recent years, the use of adaptive design methods in clinical research and development based on accrued data has become very popular because of its efficiency and flexibility in modifying trial and/or statistical procedures of ongoing clinical trials. One of the most commonly considered adaptive designs is probably a two-stage seamless adaptive trial design that combines two separate studies into one single study. In many cases, study endpoints considered in a two-stage seamless adaptive design may be similar but different (e.g. a biomarker versus a regular clinical endpoint or the same study endpoint with different treatment durations. In this case, it is important to determine how the data collected from both stages should be combined for the final analysis. It is also of interest to know how the sample size calculation/allocation should be done for achieving the study objectives originally set for the two stages (separate studies. In this article, formulas for sample size calculation/allocation are derived for cases in which the study endpoints are continuous, discrete (e.g. binary responses, and contain time-to-event data assuming that there is a well-established relationship between the study endpoints at different stages, and that the study objectives at different stages are the same. In cases in which the study objectives at different stages are different (e.g. dose finding at the first stage and efficacy confirmation at the second stage and when there is a shift in patient population caused by protocol amendments, the derived test statistics and formulas for sample size calculation and allocation are necessarily modified for controlling the overall type I error at the prespecified level.

  2. Two-Stage Fan I: Aerodynamic and Mechanical Design

    Science.gov (United States)

    Messenger, H. E.; Kennedy, E. E.

    1972-01-01

    A two-stage, highly-loaded fan was designed to deliver an overall pressure ratio of 2.8 with an adiabatic efficiency of 83.9 percent. At the first rotor inlet, design flow per unit annulus area is 42 lbm/sec/sq ft (205 kg/sec/sq m), hub/tip ratio is 0.4 with a tip diameter of 31 inches (0.787 m), and design tip speed is 1450 ft/sec (441.96 m/sec). Other features include use of multiple-circular-arc airfoils, resettable stators, and split casings over the rotor tip sections for casing treatment tests.

  3. Two-stage designs for cross-over bioequivalence trials.

    Science.gov (United States)

    Kieser, Meinhard; Rauch, Geraldine

    2015-07-20

    The topic of applying two-stage designs in the field of bioequivalence studies has recently gained attention in the literature and in regulatory guidelines. While there exists some methodological research on the application of group sequential designs in bioequivalence studies, implementation of adaptive approaches has focused up to now on superiority and non-inferiority trials. Especially, no comparison of the features and performance characteristics of these designs has been performed, and therefore, the question of which design to employ in this setting remains open. In this paper, we discuss and compare 'classical' group sequential designs and three types of adaptive designs that offer the option of mid-course sample size recalculation. A comprehensive simulation study demonstrates that group sequential designs can be identified, which show power characteristics that are similar to those of the adaptive designs but require a lower average sample size. The methods are illustrated with a real bioequivalence study example.

  4. Two-stage dental implants inserted in a one-stage procedure : a prospective comparative clinical study

    NARCIS (Netherlands)

    Heijdenrijk, Kees

    2002-01-01

    The results of this study indicate that dental implants designed for a submerged implantation procedure can be used in a single-stage procedure and may be as predictable as one-stage implants. Although one-stage implant systems and two-stage.

  5. Two-stage dental implants inserted in a one-stage procedure : a prospective comparative clinical study

    NARCIS (Netherlands)

    Heijdenrijk, Kees

    2002-01-01

    The results of this study indicate that dental implants designed for a submerged implantation procedure can be used in a single-stage procedure and may be as predictable as one-stage implants. Although one-stage implant systems and two-stage.

  6. Two-Stage Sampling Procedures for Comparing Means When Population Distributions Are Non-Normal.

    Science.gov (United States)

    Luh, Wei-Ming; Olejnik, Stephen

    Two-stage sampling procedures for comparing two population means when variances are heterogeneous have been developed by D. G. Chapman (1950) and B. K. Ghosh (1975). Both procedures assume sampling from populations that are normally distributed. The present study reports on the effect that sampling from non-normal distributions has on Type I error…

  7. Latent Inhibition as a Function of US Intensity in a Two-Stage CER Procedure

    Science.gov (United States)

    Rodriguez, Gabriel; Alonso, Gumersinda

    2004-01-01

    An experiment is reported in which the effect of unconditioned stimulus (US) intensity on latent inhibition (LI) was examined, using a two-stage conditioned emotional response (CER) procedure in rats. A tone was used as the pre-exposed and conditioned stimulus (CS), and a foot-shock of either a low (0.3 mA) or high (0.7 mA) intensity was used as…

  8. Two-stage liver transplantation: an effective procedure in urgent conditions.

    Science.gov (United States)

    Montalti, Roberto; Busani, Stefano; Masetti, Michele; Girardis, Massimo; Di Benedetto, Fabrizio; Begliomini, Bruno; Rompianesi, Gianluca; Rinaldi, Laura; Ballarin, Roberto; Pasetto, Alberto; Gerunda, Giorgio E

    2010-01-01

    Temporary portocaval shunt and total hepatectomy is a technique used in the presence of toxic liver syndrome because of fulminant hepatic failure, hepatic trauma, primary non-function (PNF), and eclampsia. We performed this technique on four patients. An indication for anhepatic state was severe hemodynamic instability in three of them. Etiologies of these three patients were as follows: PNF after liver transplantation, ischemic hepatitis after right hepatic artery embolization, and massive reperfusion syndrome during a liver transplantation. In the fourth patient, during the liver transplantation when hepatic artery was ligated, a kidney carcinoma in the donor graft was discovered. We decided to complete the hepatectomy and to construct a temporary portocaval shunt. Mean anhepatic phases were 19 h and 15 min. All patients survived the two-stage liver transplantation procedure without major complications. Our cases demonstrated that temporary portocaval shunt while awaiting urgent liver transplantation could be an effective "bridge" in selected patients who develop toxic liver syndrome; however, a short time between portocaval shunt and transplantation and careful intensive care managements are mandatory.

  9. Design and construction of the X-2 two-stage free piston driven expansion tube

    Science.gov (United States)

    Doolan, Con

    1995-01-01

    This report outlines the design and construction of the X-2 two-stage free piston driven expansion tube. The project has completed its construction phase and the facility has been installed in the new impulsive research laboratory where commissioning is about to take place. The X-2 uses a unique, two-stage driver design which allows a more compact and lower overall cost free piston compressor. The new facility has been constructed in order to examine the performance envelope of the two-stage driver and how well it couple to sub-orbital and super-orbital expansion tubes. Data obtained from these experiments will be used for the design of a much larger facility, X-3, utilizing the same free piston driver concept.

  10. Two-stage solar concentrators based on parabolic troughs: asymmetric versus symmetric designs.

    Science.gov (United States)

    Schmitz, Max; Cooper, Thomas; Ambrosetti, Gianluca; Steinfeld, Aldo

    2015-11-20

    While nonimaging concentrators can approach the thermodynamic limit of concentration, they generally suffer from poor compactness when designed for small acceptance angles, e.g., to capture direct solar irradiation. Symmetric two-stage systems utilizing an image-forming primary parabolic concentrator in tandem with a nonimaging secondary concentrator partially overcome this compactness problem, but their achievable concentration ratio is ultimately limited by the central obstruction caused by the secondary. Significant improvements can be realized by two-stage systems having asymmetric cross-sections, particularly for 2D line-focus trough designs. We therefore present a detailed analysis of two-stage line-focus asymmetric concentrators for flat receiver geometries and compare them to their symmetric counterparts. Exemplary designs are examined in terms of the key optical performance metrics, namely, geometric concentration ratio, acceptance angle, concentration-acceptance product, aspect ratio, active area fraction, and average number of reflections. Notably, we show that asymmetric designs can achieve significantly higher overall concentrations and are always more compact than symmetric systems designed for the same concentration ratio. Using this analysis as a basis, we develop novel asymmetric designs, including two-wing and nested configurations, which surpass the optical performance of two-mirror aplanats and are comparable with the best reported 2D simultaneous multiple surface designs for both hollow and dielectric-filled secondaries.

  11. Interval estimation of binomial proportion in clinical trials with a two-stage design.

    Science.gov (United States)

    Tsai, Wei-Yann; Chi, Yunchan; Chen, Chia-Min

    2008-01-15

    Generally, a two-stage design is employed in Phase II clinical trials to avoid giving patients an ineffective drug. If the number of patients with significant improvement, which is a binomial response, is greater than a pre-specified value at the first stage, then another binomial response at the second stage is also observed. This paper considers interval estimation of the response probability when the second stage is allowed to continue. Two asymptotic interval estimators, Wald and score, as well as two exact interval estimators, Clopper-Pearson and Sterne, are constructed according to the two binomial responses from this two-stage design, where the binomial response at the first stage follows a truncated binomial distribution. The mean actual coverage probability and expected interval width are employed to evaluate the performance of these interval estimators. According to the comparison results, the score interval is recommended for both Simon's optimal and minimax designs.

  12. Thermal design of two-stage evaporative cooler based on thermal comfort criterion

    Science.gov (United States)

    Gilani, Neda; Poshtiri, Amin Haghighi

    2017-04-01

    Performance of two-stage evaporative coolers at various outdoor air conditions was numerically studied, and its geometric and physical characteristics were obtained based on thermal comfort criteria. For this purpose, a mathematical model was developed based on conservation equations of mass, momentum and energy to determine heat and mass transfer characteristics of the system. The results showed that two-stage indirect/direct cooler can provide the thermal comfort condition when outdoor air temperature and relative humidity are located in the range of 34-54 °C and 10-60 %, respectively. Moreover, as relative humidity of the ambient air rises, two-stage evaporative cooler with the smaller direct and larger indirect cooler will be needed. In building with high cooling demand, thermal comfort may be achieved at a greater air change per hour number, and thus an expensive two-stage evaporative cooler with a higher electricity consumption would be required. Finally, a design guideline was proposed to determine the size of required plate heat exchangers at various operating conditions.

  13. Thermal design of two-stage evaporative cooler based on thermal comfort criterion

    Science.gov (United States)

    Gilani, Neda; Poshtiri, Amin Haghighi

    2016-09-01

    Performance of two-stage evaporative coolers at various outdoor air conditions was numerically studied, and its geometric and physical characteristics were obtained based on thermal comfort criteria. For this purpose, a mathematical model was developed based on conservation equations of mass, momentum and energy to determine heat and mass transfer characteristics of the system. The results showed that two-stage indirect/direct cooler can provide the thermal comfort condition when outdoor air temperature and relative humidity are located in the range of 34-54 °C and 10-60 %, respectively. Moreover, as relative humidity of the ambient air rises, two-stage evaporative cooler with the smaller direct and larger indirect cooler will be needed. In building with high cooling demand, thermal comfort may be achieved at a greater air change per hour number, and thus an expensive two-stage evaporative cooler with a higher electricity consumption would be required. Finally, a design guideline was proposed to determine the size of required plate heat exchangers at various operating conditions.

  14. A covariate adjusted two-stage allocation design for binary responses in randomized clinical trials.

    Science.gov (United States)

    Bandyopadhyay, Uttam; Biswas, Atanu; Bhattacharya, Rahul

    2007-10-30

    In the present work, we develop a two-stage allocation rule for binary response using the log-odds ratio within the Bayesian framework allowing the current allocation to depend on the covariate value of the current subject. We study, both numerically and theoretically, several exact and limiting properties of this design. The applicability of the proposed methodology is illustrated by using some data set. We compare this rule with some of the existing rules by computing various performance measures.

  15. Structural requirements and basic design concepts for a two-stage winged launcher system (Saenger)

    Science.gov (United States)

    Kuczera, H.; Keller, K.; Kunz, R.

    1988-10-01

    An evaluation is made of materials and structures technologies deemed capable of increasing the mass fraction-to-orbit of the Saenger two-stage launcher system while adequately addressing thermal-control and cryogenic fuel storage insulation problems. Except in its leading edges, nose cone, and airbreathing propulsion system air intakes, Ti alloy-based materials will be the basis of the airframe primary structure. Lightweight metallic thermal-protection measures will be employed. Attention is given to the design of the large lower stage element of Saenger.

  16. A stratified two-stage sampling design for digital soil mapping in a Mediterranean basin

    Science.gov (United States)

    Blaschek, Michael; Duttmann, Rainer

    2015-04-01

    The quality of environmental modelling results often depends on reliable soil information. In order to obtain soil data in an efficient manner, several sampling strategies are at hand depending on the level of prior knowledge and the overall objective of the planned survey. This study focuses on the collection of soil samples considering available continuous secondary information in an undulating, 16 km²-sized river catchment near Ussana in southern Sardinia (Italy). A design-based, stratified, two-stage sampling design has been applied aiming at the spatial prediction of soil property values at individual locations. The stratification based on quantiles from density functions of two land-surface parameters - topographic wetness index and potential incoming solar radiation - derived from a digital elevation model. Combined with four main geological units, the applied procedure led to 30 different classes in the given test site. Up to six polygons of each available class were selected randomly excluding those areas smaller than 1ha to avoid incorrect location of the points in the field. Further exclusion rules were applied before polygon selection masking out roads and buildings using a 20m buffer. The selection procedure was repeated ten times and the set of polygons with the best geographical spread were chosen. Finally, exact point locations were selected randomly from inside the chosen polygon features. A second selection based on the same stratification and following the same methodology (selecting one polygon instead of six) was made in order to create an appropriate validation set. Supplementary samples were obtained during a second survey focusing on polygons that have either not been considered during the first phase at all or were not adequately represented with respect to feature size. In total, both field campaigns produced an interpolation set of 156 samples and a validation set of 41 points. The selection of sample point locations has been done using

  17. Design and Characterization of two stage High-Speed CMOS Operational Amplifier

    Directory of Open Access Journals (Sweden)

    Rahul Chaudhari

    2014-03-01

    Full Text Available A method described in this paper is to design a Two Stage CMOS operational amplifier and analyze the effect of various aspect ratios on the characteristics of this Op-Amp, which operates at 1.8V power supply using tsmc 0.18μm CMOS technology. In this paper trade-off curves are computed between all characteristics such as Gain, PM, GBW, ICMRR, CMRR, Slew Rate etc. The OPAMP designed is a two-stage CMOS OPAMP. The OPAMP is designed to exhibit a unity gain frequency of 14MHz and exhibits a gain of 59.98dB with a 61.235 phase margin. Design has been carried out in Mentor graphics tools. Simulation results are verified using Model Sim Eldo and Design Architect IC. The task of CMOS operational amplifiers (Op-Amps design optimization is investigated in this work. This Paper focused on the optimization of various aspect ratios, which gave the result of different parameter. When this task is analyzed as a search problem, it can be translated into a multi-objective optimization application in which various Op-Amps’ specifications have to be taken into account, i.e., Gain, GBW (gain-bandwidth product, phase margin and others. The results are compared with respect to standard characteristics of the op-amp with the help of graph and table. Simulation results agree with theoretical predictions. Simulations confirm that the settling time can be further improved by increasing the value of GBW, the settling time is achieved 19ns. It has been demonstrated that when W/L increases the parameters GBW increases and settling time reduces.

  18. Surgical reconstruction of pressure ulcer defects: a single- or two-stage procedure?

    LENUS (Irish Health Repository)

    Laing, Tereze A

    2012-02-01

    BACKGROUND: The surgical management of pressure ulcers traditionally involved staged procedures, with initial debridement of necrotic or infected material followed by reconstruction at a later date when the wound was deemed viable and free of gross infection. However, over the past decade, it has been suggested that a single-stage procedure, combining initial debridement and definitive reconstruction, may provide advantages over staged surgery. We present our experience with the staged approach and review the current evidence for both methods. SUBJECTS AND SETTINGS: : We reviewed medical records of all patients referred to our service for pressure ulcer management between October 2001 and October 2007. The National Rehabilitation Hospital is the national center in Ireland for primary rehabilitation of adults and children suffering from spinal and brain injury, serving patients locally and from around the country. METHODS: All subjects who were managed surgically underwent a 2-stage procedure, with initial debridement and subsequent reconstruction. The main outcome measures were length of hospital stay, postoperative morbidity and mortality, and time to complete ulcer healing. RESULTS: Forty-one of 108 patients with 58 pressure ulcers were managed surgically. All patients underwent initial surgical debridement and 20 patients underwent subsequent pressure ulcer reconstruction. Postreconstructive complications occurred in 5 patients (20%). The mean time to complete ulcer healing was 17.4 weeks. Partial flap necrosis occurred in 3 patients, but there were no episodes of flap failure. CONCLUSIONS: We achieved favorable results with a 2-stage reconstruction technique and suggest that the paucity of evidence related to single-stage procedures does not support a change in surgical management.

  19. Precision and cost considerations for two-stage sampling in a panelized forest inventory design.

    Science.gov (United States)

    Westfall, James A; Lister, Andrew J; Scott, Charles T

    2016-01-01

    Due to the relatively high cost of measuring sample plots in forest inventories, considerable attention is given to sampling and plot designs during the forest inventory planning phase. A two-stage design can be efficient from a field work perspective as spatially proximate plots are grouped into work zones. A comparison between subsampling with units of unequal size (SUUS) and a simple random sample (SRS) design in a panelized framework assessed the statistical and economic implications of using the SUUS design for a case study in the Northeastern USA. The sampling errors for estimates of forest land area and biomass were approximately 1.5-2.2 times larger with SUUS prior to completion of the inventory cycle. Considerable sampling error reductions were realized by using the zones within a post-stratified sampling paradigm; however, post-stratification of plots in the SRS design always provided smaller sampling errors in comparison. Cost differences between the two designs indicated the SUUS design could reduce the field work expense by 2-7 %. The results also suggest the SUUS design may provide substantial economic advantage for tropical forest inventories, where remote areas, poor access, and lower wages are typically encountered.

  20. Two-stage re-estimation adaptive design: a simulation study

    Directory of Open Access Journals (Sweden)

    Francesca Galli

    2013-10-01

    Full Text Available Background: adaptive clinical trial design has been proposed as a promising new approach to improve the drug discovery process. Among the many options available, adaptive sample size re-estimation is of great interest mainly because of its ability to avoid a large ‘up-front’ commitment of resources. In this simulation study, we investigate the statistical properties of two-stage sample size re-estimation designs in terms of type I error control, study power and sample size, in comparison with the fixed-sample study.Methods: we simulated a balanced two-arm trial aimed at comparing two means of normally distributed data, using the inverse normal method to combine the results of each stage, and considering scenarios jointly defined by the following factors: the sample size re-estimation method, the information fraction, the type of group sequential boundaries and the use of futility stopping. Calculations were performed using the statistical software SAS™ (version 9.2.Results: under the null hypothesis, any type of adaptive design considered maintained the prefixed type I error rate, but futility stopping was required to avoid the unwanted increase in sample size. When deviating from the null hypothesis, the gain in power usually achieved with the adaptive design and its performance in terms of sample size were influenced by the specific design options considered.Conclusions: we show that adaptive designs incorporating futility stopping, a sufficiently high information fraction (50-70% and the conditional power method for sample size re-estimation have good statistical properties, which include a gain in power when trial results are less favourable than anticipated. 

  1. Two-Stage Experimental Design for Dose–Response Modeling in Toxicology Studies

    OpenAIRE

    Wang, Kai; Yang, Feng; Porter, Dale W; Wu, Nianqiang

    2013-01-01

    The efficient design of experiments (i.e., selection of experimental doses and allocation of animals) is important to establishing dose–response relationships in toxicology studies. The proposed procedure for design of experiments is distinct from those in the literature because it is able to adequately accommodate the special features of the dose–response data, which include non-normality, variance heterogeneity, possibly nonlinearity of the dose–response curve, and data scarcity. The design...

  2. Two-stage collaborative global optimization design model of the CHPG microgrid

    Science.gov (United States)

    Liao, Qingfen; Xu, Yeyan; Tang, Fei; Peng, Sicheng; Yang, Zheng

    2017-06-01

    With the continuous developing of technology and reducing of investment costs, renewable energy proportion in the power grid is becoming higher and higher because of the clean and environmental characteristics, which may need more larger-capacity energy storage devices, increasing the cost. A two-stage collaborative global optimization design model of the combined-heat-power-and-gas (abbreviated as CHPG) microgrid is proposed in this paper, to minimize the cost by using virtual storage without extending the existing storage system. P2G technology is used as virtual multi-energy storage in CHPG, which can coordinate the operation of electric energy network and natural gas network at the same time. Demand response is also one kind of good virtual storage, including economic guide for the DGs and heat pumps in demand side and priority scheduling of controllable loads. Two kinds of storage will coordinate to smooth the high-frequency fluctuations and low-frequency fluctuations of renewable energy respectively, and achieve a lower-cost operation scheme simultaneously. Finally, the feasibility and superiority of proposed design model is proved in a simulation of a CHPG microgrid.

  3. The role of the upper sample size limit in two-stage bioequivalence designs.

    Science.gov (United States)

    Karalis, Vangelis

    2013-11-01

    Two-stage designs (TSDs) are currently recommended by the regulatory authorities for bioequivalence (BE) assessment. The TSDs presented until now rely on an assumed geometric mean ratio (GMR) value of the BE metric in stage I in order to avoid inflation of type I error. In contrast, this work proposes a more realistic TSD design where sample re-estimation relies not only on the variability of stage I, but also on the observed GMR. In these cases, an upper sample size limit (UL) is introduced in order to prevent inflation of type I error. The aim of this study is to unveil the impact of UL on two TSD bioequivalence approaches which are based entirely on the interim results. Monte Carlo simulations were used to investigate several different scenarios of UL levels, within-subject variability, different starting number of subjects, and GMR. The use of UL leads to no inflation of type I error. As UL values increase, the % probability of declaring BE becomes higher. The starting sample size and the variability of the study affect type I error. Increased UL levels result in higher total sample sizes of the TSD which are more pronounced for highly variable drugs.

  4. Design and Analysis of a Split Deswirl Vane in a Two-Stage Refrigeration Centrifugal Compressor

    Directory of Open Access Journals (Sweden)

    Jeng-Min Huang

    2014-09-01

    Full Text Available This study numerically investigated the influence of using the second row of a double-row deswirl vane as the inlet guide vane of the second stage on the performance of the first stage in a two-stage refrigeration centrifugal compressor. The working fluid was R134a, and the turbulence model was the Spalart-Allmaras model. The parameters discussed included the cutting position of the deswirl vane, the staggered angle of two rows of vane, and the rotation angle of the second row. The results showed that the performance of staggered angle 7.5° was better than that of 15° or 22.5°. When the staggered angle was 7.5°, the performance of cutting at 1/3 and 1/2 of the original deswirl vane length was slightly different from that of the original vane but obviously better than that of cutting at 2/3. When the staggered angle was 15°, the cutting position influenced the performance slightly. At a low flow rate prone to surge, when the second row at a staggered angle 7.5° cutting at the half of vane rotated 10°, the efficiency was reduced by only about 0.6%, and 10% of the swirl remained as the preswirl of the second stage, which is generally better than other designs.

  5. A two-stage procedure for determining unsaturated hydraulic characteristics using a syringe pump and outflow observations

    DEFF Research Database (Denmark)

    Wildenschild, Dorthe; Jensen, Karsten Høgh; Hollenbeck, Karl-Josef;

    1997-01-01

    A fast two-stage methodology for determining unsaturated flow characteristics is presented. The procedure builds on direct measurement of the retention characteristic using a syringe pump technique, combined with inverse estimation of the hydraulic conductivity characteristic based on one......-step outflow experiments. The direct measurements are obtained with a commercial syringe pump, which continuously withdraws fluid from a soil sample at a very low and accurate how rate, thus providing the water content in the soil sample. The retention curve is then established by simultaneously monitoring......-step outflow data and the independently measured retention data are included in the objective function of a traditional least-squares minimization routine, providing unique estimates of the unsaturated hydraulic characteristics by means of numerical inversion of Richards equation. As opposed to what is often...

  6. The Design, Construction and Operation of a 75 kW Two-Stage Gasifier

    DEFF Research Database (Denmark)

    Henriksen, Ulrik Birk; Ahrenfeldt, Jesper; Jensen, Torben Kvist

    2003-01-01

    The Two-Stage Gasifier was operated for several weeks (465 hours) and of these 190 hours continuously. The gasifier is operated automatically unattended day and night, and only small adjustments of the feeding rate were necessary once or twice a day. The operation was successful, and the output a...... of the reactor had to be constructed in some other material....

  7. Some design aspects of a two-stage rail-to-rail CMOS op amp

    NARCIS (Netherlands)

    Gierkink, S.L.J.; Holzmann, Peter J.; Wiegerink, R.J.; Wassenaar, R.F.

    1999-01-01

    A two-stage low-voltage CMOS op amp with rail-to-rail input and output voltage ranges is presented. The circuit uses complementary differential input pairs to achieve the rail-to-rail common-mode input voltage range. The differential pairs operate in strong inversion, and the constant transconductan

  8. Two-stage culture procedure using thidiazuron for efficient micropropagation of Stevia rebaudiana, an anti-diabetic medicinal herb.

    Science.gov (United States)

    Singh, Pallavi; Dwivedi, Padmanabh

    2014-08-01

    Stevia rebaudiana Bertoni, member of Asteraceae family, has bio-active compounds stevioside and rebaudioside which taste about 300 times sweeter than sucrose. It regulates blood sugar, prevents hypertension and tooth decay as well as used in treatment of skin disorders having high medicinal values, and hence there is a need for generating the plant on large scale. We have developed an efficient micropropagation protocol on half strength Murashige and Skoog (MS) media, using two-stage culture procedures. Varying concentrations of cytokinins, i.e., benzylaminopurine, kinetin and thidiazuron (TDZ) were supplemented in the nutrient media to observe their effects on shoot development. All the cytokinins promoted shoot formation, however, best response was observed in the TDZ (0.5 mg/l). The shoots from selected induction medium were sub-cultured on the multiplication media. The media containing 0.01 mg/l TDZ produced maximum number of shoot (11.00 ± 0.40) with longer shoots (7.17 ± 0.16) and highest number of leaves (61.00 ± 1.29). Rooting response was best observed in one-fourth strength on MS media supplemented with indole-3-butyric acid (1.0 mg/l) and activated charcoal (50 mg/l) with (11.00 ± 0.40) number of roots. The plantlets thus obtained were hardened and transferred to the pots with soil and sand mixture, where the survival rate was 80 % after 2 months. Quantitative analysis of stevioside content in leaves of in vivo mother plant and in vitro plantlets was carried out by high performance liquid chromatography. A remarkable increase in stevioside content was noticed in the in vitro-raised plants as compared to in vivo grown plants. The protocol reported here might be useful in genetic improvement and high stevioside production.

  9. On Simon's two-stage design for single-arm phase IIA cancer clinical trials under beta-binomial distribution.

    Science.gov (United States)

    Liu, Junfeng; Lin, Yong; Shih, Weichung Joe

    2010-05-10

    Simon (Control. Clin. Trials 1989; 10:1-10)'s two-stage design has been broadly applied to single-arm phase IIA cancer clinical trials in order to minimize either the expected or the maximum sample size under the null hypothesis of drug inefficacy, i.e. when the pre-specified amount of improvement in response rate (RR) is not expected to be observed. This paper studies a realistic scenario where the standard and experimental treatment RRs follow two continuous distributions (e.g. beta distribution) rather than two single values. The binomial probabilities in Simon's (Control. Clin. Trials 1989; 10:1-10) design are replaced by prior predictive Beta-binomial probabilities that are the ratios of two beta functions and domain-restricted RRs involve incomplete beta functions to induce the null hypothesis acceptance probability. We illustrate that Beta-binomial mixture model based two-stage design retains certain desirable properties for hypothesis testing purpose. However, numerical results show that such designs may not exist under certain hypothesis and error rate (type I and II) setups within maximal sample size approximately 130. Furthermore, we give theoretical conditions for asymptotic two-stage design non-existence (sample size goes to infinity) in order to improve the efficiency of design search and to avoid needless searching.

  10. On the design of a low-voltage two-stage OTA using bulk-driven and positive feedback techniques

    Science.gov (United States)

    Khameh, Hassan; Shamsi, Hossein

    2012-09-01

    This article presents the design and simulation of a fully differential two-stage operational transconductance amplifier (OTA) in a 0.18 µm CMOS process with a 0.9 V supply voltage. For this purpose, both the bulk-driven and positive feedback techniques are employed. These techniques increase the DC gain by about 18.5 dB without consuming more power and changing the unity-gain bandwidth and phase margin of the OTA.

  11. A GRASP model in network design for two-stage supply chain

    Directory of Open Access Journals (Sweden)

    Hassan Javanshir

    2011-04-01

    Full Text Available We consider a capacitated facility location problem (CFLP which contains a production facility and distribution centers (DCs supplying retailers' demand. The primary purpose is to locate distribution centres in the network and the objective is the minimization of the sum of fixed facility location, pipeline inventory, safety stock and lost sales. We use Greedy randomized adaptive search procedures (GRASP to solve the model. The preliminary results indicate that the proposed method of this paper could provide competitive results in reasonable amount time.

  12. OPTIMIZING THE PRECISION OF TOXICITY THRESHOLD ESTIMATION USING A TWO-STAGE EXPERIMENTAL DESIGN

    Science.gov (United States)

    An important consideration for risk assessment is the existence of a threshold, i.e., the highest toxicant dose where the response is not distinguishable from background. We have developed methodology for finding an experimental design that optimizes the precision of threshold mo...

  13. Design of a Scalable Modular Production System for a Two-stage Food Service Franchise System

    Directory of Open Access Journals (Sweden)

    Matt

    2012-11-01

    industrial case. Information was collected through multiple site visits, workshops and semi‐structured interviews with the company’s key staff of the project, as well as examination of relevant company documentations. By means of a scenario for the Central European market, the model was reviewed in terms of its development potential and finally approved for implementation. However, research through case survey requires further empirical investigation to fully establish this approach as a valid and reliable design tool.

  14. A Two-Stage Layered Mixture Experiment Design for a Nuclear Waste Glass Application-Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, Scott K.; Piepel, Gregory F.; Gan, Hao; Kot, Wing; Pegg, Ian L.

    2003-12-01

    Part 1 (Cooley and Piepel, 2003a) describes the first stage of a two-stage experimental design to support property-composition modeling for high-level waste (HLW) glass to be produced at the Hanford Site in Washington state. Each stage used a layered design having an outer layer, an inner layer, a center point, and some replicates. However, the design variables and constraints defining the layers of the experimental glass composition region (EGCR) were defined differently for the second stage than for the first. The first-stage initial design involved 15 components, all treated as mixture variables. The second-stage augmentation design involved 19 components, with 14 treated as mixture variables and 5 treated as non-mixture variables. For each second-stage layer, vertices were generated and optimal design software was used to select alternative subsets of vertices for the design and calculate design optimality measures. A model containing 29 partial quadratic mixture terms plus 5 linear terms for the non-mixture variables was the basis for the optimal design calculations. Predicted property values were plotted for the alternative subsets of second-stage vertices and the first-stage design points. Based on the optimality measures and the predicted property distributions, a ''best'' subset of vertices was selected for each layer of the second-stage to augment the first-stage design.

  15. Investigation of two-stage air-cooled turbine suitable for flight at Mach number of 2.5 II : blade design

    Science.gov (United States)

    Miser, James W; Stewart, Warner L

    1957-01-01

    A blade design study is presented for a two-stage air-cooled turbine suitable for flight at a Mach number of 2.5 for which velocity diagrams have been previously obtained. The detailed procedure used in the design of the blades is given. In addition, the design blade shapes, surface velocity distributions, inner and outer wall contours, and other design data are presented. Of all the blade rows, the first-stage rotor has the highest solidity, with a value of 2.289 at the mean section. The second-stage stator also had a high mean-section solidity of 1.927, mainly because of its high inlet whirl. The second-stage rotor has the highest value of the suction-surface diffusion parameter, with a value of 0.151. All other blade rows have values for this parameter under 0.100.

  16. A Two-Stage Layered Mixture Experiment Design for a Nuclear Waste Glass Application-Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, Scott K.; Piepel, Gregory F.; Gan, Hao; Kot, Wing; Pegg, Ian L.

    2003-12-01

    A layered experimental design involving mixture variables was generated to support developing property-composition models for high-level waste (HLW) glasses. The design was generated in two stages, each having unique characteristics. Each stage used a layered design having an outer layer, an inner layer, a center point, and some replicates. The layers were defined by single- and multi-variable constraints. The first stage involved 15 glass components treated as mixture variables. For each layer, vertices were generated and optimal design software was used to select alternative subsets of vertices and calculate design optimality measures. Two partial quadratic mixture models, containing 25 terms for the outer layer and 30 terms for the inner layer, were the basis for the optimal design calculations. Distributions of predicted glass property values were plotted and evaluated for the alternative subsets of vertices. Based on the optimality measures and the predicted property distributions, a ''best'' subset of vertices was selected for each layer to form a layered design for the first stage. The design for the second stage was selected to augment the first-stage design. The discussion of the second-stage design begins in this Part 1 and is continued in Part 2 (Cooley and Piepel, 2003b).

  17. A two-stage algorithm for designing phase I cancer clinical trials for two new molecular entities.

    Science.gov (United States)

    Su, Zheng

    2010-01-01

    The continual reassessment method (CRM) and subsequent developments of the Bayesian approach provide important tools for the design of Phase I cancer clinical trials for a new molecular entity. In recent years the idea of developing a treatment composed of two molecular entities has been proposed. For example, for some tumor types there may be two signaling pathways, both of which need to be blocked simultaneously using two molecules to achieve therapeutic benefit. A two-stage Bayesian and likelihood based algorithm is introduced herein for designing Phase I cancer clinical trials for two new molecular entities. It starts with a modified CRM approach in the first stage and makes use of the accumulated data from the first stage to provide likelihood estimates of model parameters for use in the second stage. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  18. Accounting for uncertainty in the historical response rate of the standard treatment in single-arm two-stage designs based on Bayesian power functions.

    Science.gov (United States)

    Matano, Francesca; Sambucini, Valeria

    2016-11-01

    In phase II single-arm studies, the response rate of the experimental treatment is typically compared with a fixed target value that should ideally represent the true response rate for the standard of care therapy. Generally, this target value is estimated through previous data, but the inherent variability in the historical response rate is not taken into account. In this paper, we present a Bayesian procedure to construct single-arm two-stage designs that allows to incorporate uncertainty in the response rate of the standard treatment. In both stages, the sample size determination criterion is based on the concepts of conditional and predictive Bayesian power functions. Different kinds of prior distributions, which play different roles in the designs, are introduced, and some guidelines for their elicitation are described. Finally, some numerical results about the performance of the designs are provided and a real data example is illustrated. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Two-Stage Design Method for Enhanced Inductive Energy Transmission with Q-Constrained Planar Square Loops.

    Directory of Open Access Journals (Sweden)

    Akaa Agbaeze Eteng

    Full Text Available Q-factor constraints are usually imposed on conductor loops employed as proximity range High Frequency Radio Frequency Identification (HF-RFID reader antennas to ensure adequate data bandwidth. However, pairing such low Q-factor loops in inductive energy transmission links restricts the link transmission performance. The contribution of this paper is to assess the improvement that is reached with a two-stage design method, concerning the transmission performance of a planar square loop relative to an initial design, without compromise to a Q-factor constraint. The first stage of the synthesis flow is analytical in approach, and determines the number and spacing of turns by which coupling between similar paired square loops can be enhanced with low deviation from the Q-factor limit presented by an initial design. The second stage applies full-wave electromagnetic simulations to determine more appropriate turn spacing and widths to match the Q-factor constraint, and achieve improved coupling relative to the initial design. Evaluating the design method in a test scenario yielded a more than 5% increase in link transmission efficiency, as well as an improvement in the link fractional bandwidth by more than 3%, without violating the loop Q-factor limit. These transmission performance enhancements are indicative of a potential for modifying proximity HF-RFID reader antennas for efficient inductive energy transfer and data telemetry links.

  20. A two-stage Bayesian design with sample size reestimation and subgroup analysis for phase II binary response trials.

    Science.gov (United States)

    Zhong, Wei; Koopmeiners, Joseph S; Carlin, Bradley P

    2013-11-01

    Frequentist sample size determination for binary outcome data in a two-arm clinical trial requires initial guesses of the event probabilities for the two treatments. Misspecification of these event rates may lead to a poor estimate of the necessary sample size. In contrast, the Bayesian approach that considers the treatment effect to be random variable having some distribution may offer a better, more flexible approach. The Bayesian sample size proposed by (Whitehead et al., 2008) for exploratory studies on efficacy justifies the acceptable minimum sample size by a "conclusiveness" condition. In this work, we introduce a new two-stage Bayesian design with sample size reestimation at the interim stage. Our design inherits the properties of good interpretation and easy implementation from Whitehead et al. (2008), generalizes their method to a two-sample setting, and uses a fully Bayesian predictive approach to reduce an overly large initial sample size when necessary. Moreover, our design can be extended to allow patient level covariates via logistic regression, now adjusting sample size within each subgroup based on interim analyses. We illustrate the benefits of our approach with a design in non-Hodgkin lymphoma with a simple binary covariate (patient gender), offering an initial step toward within-trial personalized medicine. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. A Two-Stage Taguchi Design ExampleImage Quality Promotion in Miniature Camera/Cell-Phone Lens

    Directory of Open Access Journals (Sweden)

    Luke K. Wang

    2012-07-01

    Full Text Available A simple, practical manufacturing process, integrating manufacturing capability-oriented design (MCOD philosophy and Taguchi’s method, is presented to tackle the high resolution miniature camera/cell phone lens issues at the manufacturing phase. Meanwhile, we also use optical software to create an analytical simulation model to investigate the quality characteristics due to lens’ thickness, eccentricity, surface profile, and air lens’ gap; a single quality characteristics expressed in terms of modulation transfer function (MTF is defined. Optimal combination of process parameters in experimental scenario using Taguchi’s method is performed, and the results are judged and analyzed by the indices of signal-to-noise ratio (S/N and the analysis of variance (ANOVA. The key idea of the two-stage design is to utilize optical software to conduct the sensitivity analysis of MTF first; an analytical model, dependent on actual process parameters at manufacturing stage, is constructed next; and finally by substituting these outputs from the analytical model back to the optical software to verify the design criterion and do the modifications. By minimizing both the theoretical errors at design stage and the complexity in the manufacturing process, we are able to seeking for the most economical solution, simultaneously attain the optimal/suboptimal combination of process parameters or control factors in lens manufacturing issue.

  2. Experiences from the full-scale implementation of a new two-stage vertical flow constructed wetland design.

    Science.gov (United States)

    Langergraber, Guenter; Pressl, Alexander; Haberl, Raimund

    2014-01-01

    This paper describes the results of the first full-scale implementation of a two-stage vertical flow constructed wetland (CW) system developed to increase nitrogen removal. The full-scale system was constructed for the Bärenkogelhaus, which is located in Styria at the top of a mountain, 1,168 m above sea level. The Bärenkogelhaus has a restaurant with 70 seats, 16 rooms for overnight guests and is a popular site for day visits, especially during weekends and public holidays. The CW treatment system was designed for a hydraulic load of 2,500 L.d(-1) with a specific surface area requirement of 2.7 m(2) per person equivalent (PE). It was built in fall 2009 and started operation in April 2010 when the restaurant was re-opened. Samples were taken between July 2010 and June 2013 and were analysed in the laboratory of the Institute of Sanitary Engineering at BOKU University using standard methods. During 2010 the restaurant at Bärenkogelhaus was open 5 days a week whereas from 2011 the Bärenkogelhaus was open only on demand for events. This resulted in decreased organic loads of the system in the later period. In general, the measured effluent concentrations were low and the removal efficiencies high. During the whole period the ammonia nitrogen effluent concentration was below 1 mg/L even at effluent water temperatures below 3 °C. Investigations during high-load periods, i.e. events like weddings and festivals at weekends, with more than 100 visitors, showed a very robust treatment performance of the two-stage CW system. Effluent concentrations of chemical oxygen demand and NH4-N were not affected by these events with high hydraulic loads.

  3. Application of composite estimation in studies of animal population production with two-stage repeated sample designs.

    Science.gov (United States)

    Farver, T B; Holt, D; Lehenbauer, T; Greenley, W M

    1997-05-01

    This paper reports results from two example data sets of a two-stage sampling design where sampling (in panels) both farms and animals within selected farms increases the efficiency of parameter estimation from measurements recorded over time. With such a design, not only are farms replaced from time-to-time but also animals subsampled within retained farms are subject to replacement. Three general categories of parameters estimated for the population (the set of animals belonging to the universe of farms of interest) were (1) the total at each measurement occasion; (2) the difference between means or totals on successive measurement occasions; (3) the total over a sequence of successive measurement periods. Whereas several responses at the farm level were highly correlated over time (rho 1), the corresponding animal responses were less correlated over time (rho 2)-leading to only moderate gains in relative efficiency. Intraclass correlation values were too low in most cases to counteract the overall negative impact of rho 2. In general, sizeable gains in relative efficiency were observed for estimating change-confirming a previous result which showed this to be true provided that rho 1 was high (irrespective of rho 2).

  4. Advanced LIGO Two-Stage Twelve-Axis Vibration Isolation and Positioning Platform. Part 1: Design and Production Overview

    CERN Document Server

    Matichard, Fabrice; Mason, Kenneth; Mittleman, Richard; Abbott, Benjamin; Abbott, Samuel; Allwine, Eric; Barnum, Samuel; Birch, Jeremy; Biscans, Sebastien; Clark, Daniel; Coyne, Dennis; DeBra, Dan; DeRosa, Ryan; Foley, Stephany; Fritschel, Peter; Giaime, Joseph A; Gray, Corey; Grabeel, Gregory; Hanson, Joe; Hillard, Michael; Kissel, Jeffrey; Kucharczyk, Christopher; Roux, Adrien Le; Lhuillier, Vincent; Macinnis, Myron; OReilly, Brian; Ottaway, David; Paris, Hugo; Puma, Michael; Radkins, Hugh; Ramet, Celine; Robinson, Mitchell; Ruet, Laurent; Sareen, Pradeep; Shoemaker, Daivid; Stein, Andy; Thomas, Jeremy; Vargas, Michael; Warner, Jimmy

    2014-01-01

    New generations of gravity wave detectors require unprecedented levels of vibration isolation. This paper presents the final design of the vibration isolation and positioning platform used in Advanced LIGO to support the interferometers core optics. This five-ton two-and-half-meter wide system operates in ultra-high vacuum. It features two stages of isolation mounted in series. The stages are imbricated to reduce the overall height. Each stage provides isolation in all directions of translation and rotation. The system is instrumented with a unique combination of low noise relative and inertial sensors. The active control provides isolation from 0.1 Hz to 30 Hz. It brings the platform motion down to 10^(-11) m/Hz^(0.5) at 1 Hz. Active and passive isolation combine to bring the platform motion below 10^(-12) m/Hz^(0.5) at 10 Hz. The passive isolation lowers the motion below 10^(-13) m/Hz^(0.5) at 100 Hz. The paper describes how the platform has been engineered not only to meet the isolation requirements, but a...

  5. A two-stage strategy to accommodate general patterns of confounding in the design of observational studies.

    Science.gov (United States)

    Haneuse, Sebastien; Schildcrout, Jonathan; Gillen, Daniel

    2012-04-01

    Accommodating general patterns of confounding in sample size/power calculations for observational studies is extremely challenging, both technically and scientifically. While employing previously implemented sample size/power tools is appealing, they typically ignore important aspects of the design/data structure. In this paper, we show that sample size/power calculations that ignore confounding can be much more unreliable than is conventionally thought; using real data from the US state of North Carolina, naive calculations yield sample size estimates that are half those obtained when confounding is appropriately acknowledged. Unfortunately, eliciting realistic design parameters for confounding mechanisms is difficult. To overcome this, we propose a novel two-stage strategy for observational study design that can accommodate arbitrary patterns of confounding. At the first stage, researchers establish bounds for power that facilitate the decision of whether or not to initiate the study. At the second stage, internal pilot data are used to estimate key scientific inputs that can be used to obtain realistic sample size/power. Our results indicate that the strategy is effective at replicating gold standard calculations based on knowing the true confounding mechanism. Finally, we show that consideration of the nature of confounding is a crucial aspect of the elicitation process; depending on whether the confounder is positively or negatively associated with the exposure of interest and outcome, naive power calculations can either under or overestimate the required sample size. Throughout, simulation is advocated as the only general means to obtain realistic estimates of statistical power; we describe, and provide in an R package, a simple algorithm for estimating power for a case-control study.

  6. Mixed effect regression analysis for a cluster-based two-stage outcome-auxiliary-dependent sampling design with a continuous outcome.

    Science.gov (United States)

    Xu, Wangli; Zhou, Haibo

    2012-09-01

    Two-stage design is a well-known cost-effective way for conducting biomedical studies when the exposure variable is expensive or difficult to measure. Recent research development further allowed one or both stages of the two-stage design to be outcome dependent on a continuous outcome variable. This outcome-dependent sampling feature enables further efficiency gain in parameter estimation and overall cost reduction of the study (e.g. Wang, X. and Zhou, H., 2010. Design and inference for cancer biomarker study with an outcome and auxiliary-dependent subsampling. Biometrics 66, 502-511; Zhou, H., Song, R., Wu, Y. and Qin, J., 2011. Statistical inference for a two-stage outcome-dependent sampling design with a continuous outcome. Biometrics 67, 194-202). In this paper, we develop a semiparametric mixed effect regression model for data from a two-stage design where the second-stage data are sampled with an outcome-auxiliary-dependent sample (OADS) scheme. Our method allows the cluster- or center-effects of the study subjects to be accounted for. We propose an estimated likelihood function to estimate the regression parameters. Simulation study indicates that greater study efficiency gains can be achieved under the proposed two-stage OADS design with center-effects when compared with other alternative sampling schemes. We illustrate the proposed method by analyzing a dataset from the Collaborative Perinatal Project.

  7. Design and Characterization of Thin Stainless Steel Burst Disks for Increasing Two-Stage Light Gas Launcher Efficiency

    Science.gov (United States)

    Tylka, Jonathan M.; Johnson, Kenneth L.; Henderson, Donald; Rodriguez, Karen

    2012-01-01

    Laser etched 300 series Stainless Steel Burst Disks (SSBD) ranging between 0.178 mm (0.007-in.) and 0.508mm (0.020-in.) thick were designed for use in a 17-caliber two-stage light gas launcher. First, a disk manufacturing method was selected using a combination of wire electrical discharge machining (EDM) to form the blank disks and laser etching to define the pedaling fracture pattern. Second, a replaceable insert was designed to go between the SSDB and the barrel. This insert reduced the stress concentration between the SSBD and the barrel, providing a place for the petals of the SSDB to open, and protecting the rifling on the inside of the barrel. Thereafter, a design of experiments was implemented to test and characterize the burst characteristics of SSBDs. Extensive hydrostatic burst testing of the SSBDs was performed to complete the design of experiments study with one-hundred and seven burst tests. The experiment simultaneously tested the effects of the following: two SSBD material states (full hard, annealed); five SSBD thicknesses 0.178, 0.254, 0.305, 0.381 mm (0.007, 0.010, 0.012, 0.015, 0.020-in.); two grain directions relative); number of times the laser etch pattern was repeated (varies between 5-200 times); two heat sink configurations (with and without heat sink); and, two barrel configurations (with and without insert). These tests resulted in the quantification of the relationship between SSBD thickness, laser etch parameters, and desired burst pressure. Of the factors investigated only thickness and number of laser etches were needed to develop a mathematical relationship predicting hydrostatic burst pressure of disks using the same barrel configuration. The fracture surfaces of two representative SSBD bursts were then investigated with a scanning electron microscope, one burst hydrostatically in a fixture and another dynamically in the launcher. The fracture analysis verified that both burst conditions resulted in a ductile overload failure

  8. Studying feasibility and effects of a two-stage nursing staff training in residential geriatric care using a 30 month mixed-methods design [ISRCTN24344776

    Directory of Open Access Journals (Sweden)

    Hantikainen Virpi

    2011-05-01

    Full Text Available Abstract Background Transfer techniques and lifting weights often cause back pain and disorders for nurses in geriatric care. The Kinaesthetics care conception claims to be an alternative, yielding benefits for nurses as well as for clients. Starting a multi-step research program on the effects of Kinaesthetics, we assess the feasibility of a two-stage nursing staff training and a pre-post research design. Using quantitative and qualitative success criteria, we address mobilisation from the bed to a chair and backwards, walking with aid and positioning in bed on the staff level as well as on the resident level. In addition, effect estimates should help to decide on and to prepare a controlled trial. Methods/Design Standard basic and advanced Kinaesthetics courses (each comprising four subsequent days and an additional counselling day during the following four months are offered to n = 36 out of 60 nurses in a residential geriatric care home, who are in charge of 76 residents. N = 22 residents needing movement support are participating to this study. On the staff level, measurements include focus group discussions, questionnaires, physical strain self-assessment (Borg scale, video recordings and external observation of patient assistance skills using a specialised instrument (SOPMAS. Questionnaires used on the resident level include safety, comfort, pain, and level of own participation during mobilisation. A functional mobility profile is assessed using a specialised test procedure (MOTPA. Measurements will take place at baseline (T0, after basic training (T1, and after the advanced course (T2. Follow-up focus groups will be offered at T1 and 10 months later (T3. Discussion Ten criteria for feasibility success are established before the trial, assigned to resources (missing data, processes (drop-out of nurses and residents and science (minimum effects criteria. This will help to make rational decision on entering the next stage of the research

  9. Evaluation of single and two-stage adaptive sampling designs for estimation of density and abundance of freshwater mussels in a large river

    Science.gov (United States)

    Smith, D.R.; Rogala, J.T.; Gray, B.R.; Zigler, S.J.; Newton, T.J.

    2011-01-01

    Reliable estimates of abundance are needed to assess consequences of proposed habitat restoration and enhancement projects on freshwater mussels in the Upper Mississippi River (UMR). Although there is general guidance on sampling techniques for population assessment of freshwater mussels, the actual performance of sampling designs can depend critically on the population density and spatial distribution at the project site. To evaluate various sampling designs, we simulated sampling of populations, which varied in density and degree of spatial clustering. Because of logistics and costs of large river sampling and spatial clustering of freshwater mussels, we focused on adaptive and non-adaptive versions of single and two-stage sampling. The candidate designs performed similarly in terms of precision (CV) and probability of species detection for fixed sample size. Both CV and species detection were determined largely by density, spatial distribution and sample size. However, designs did differ in the rate that occupied quadrats were encountered. Occupied units had a higher probability of selection using adaptive designs than conventional designs. We used two measures of cost: sample size (i.e. number of quadrats) and distance travelled between the quadrats. Adaptive and two-stage designs tended to reduce distance between sampling units, and thus performed better when distance travelled was considered. Based on the comparisons, we provide general recommendations on the sampling designs for the freshwater mussels in the UMR, and presumably other large rivers.

  10. Design, Modelling and Simulation of Two-Phase Two-Stage Electronic System with Orthogonal Output for Supplying of Two-Phase ASM

    Directory of Open Access Journals (Sweden)

    Michal Prazenica

    2011-01-01

    Full Text Available This paper deals with the two-stage two-phase electronic systems with orthogonal output voltages and currents - DC/AC/AC. Design of two-stage DC/AC/AC high frequency converter with two-phase orthogonal output using single-phase matrix converter is also introduced. Output voltages of them are strongly nonharmonic ones, so they must be pulse-modulated due to requested nearly sinusoidal currents with low total harmonic distortion. Simulation experiment results of matrix converter for both steady and transient states for IM motors are given in the paper, also experimental verification under R-L load, so far. The simulation results confirm a very good time-waveform of the phase current and the system seems to be suitable for low-cost application in automotive/aerospace industries and application with high frequency voltage sources.

  11. Two-Stage Control Design of a Buck Converter/DC Motor System without Velocity Measurements via a Σ−Δ-Modulator

    OpenAIRE

    R. Silva-Ortigoza; García-Sánchez, J. R.; J. M. Alba-Martínez; Hernández-Guzmán, V. M.; Marcelino-Aranda, M.; Taud, H.; Bautista-Quintero, R.

    2013-01-01

    This paper presents a two-stage control design for the “Buck power converter/DC motor” system, which allows to perform the sensorless angular velocity trajectory tracking task. The differential flatness property of the DC-motor model is exploited in order to propose a first-stage controller, which is designed to achieve the desired angular velocity trajectory. This controller provides the voltage profiles that must be tracked by the Buck converter. Then, a second-stage controller is meant to ...

  12. Designing Flight Deck Procedures

    Science.gov (United States)

    Degani, Asaf; Wiener, Earl

    2005-01-01

    Three reports address the design of flight-deck procedures and various aspects of human interaction with cockpit systems that have direct impact on flight safety. One report, On the Typography of Flight- Deck Documentation, discusses basic research about typography and the kind of information needed by designers of flight deck documentation. Flight crews reading poorly designed documentation may easily overlook a crucial item on the checklist. The report surveys and summarizes the available literature regarding the design and typographical aspects of printed material. It focuses on typographical factors such as proper typefaces, character height, use of lower- and upper-case characters, line length, and spacing. Graphical aspects such as layout, color coding, fonts, and character contrast are discussed; and several cockpit conditions such as lighting levels and glare are addressed, as well as usage factors such as angular alignment, paper quality, and colors. Most of the insights and recommendations discussed in this report are transferable to paperless cockpit systems of the future and computer-based procedure displays (e.g., "electronic flight bag") in aerospace systems and similar systems that are used in other industries such as medical, nuclear systems, maritime operations, and military systems.

  13. Crystal Structures and Inhibition Kinetics Reveal a Two-Stage Catalytic Mechanism with Drug Design Implications for Rhomboid Proteolysis.

    Science.gov (United States)

    Cho, Sangwoo; Dickey, Seth W; Urban, Siniša

    2016-02-04

    Intramembrane proteases signal by releasing proteins from the membrane, but despite their importance, their enzymatic mechanisms remain obscure. We probed rhomboid proteases with reversible, mechanism-based inhibitors that allow precise kinetic analysis and faithfully mimic the transition state structurally. Unexpectedly, inhibition by peptide aldehydes is non-competitive, revealing that in the Michaelis complex, substrate does not contact the catalytic center. Structural analysis in a membrane revealed that all extracellular loops of rhomboid make stabilizing interactions with substrate, but mainly through backbone interactions, explaining rhomboid's broad sequence selectivity. At the catalytic site, the tetrahedral intermediate lies covalently attached to the catalytic serine alone, with the oxyanion stabilized by unusual tripartite interactions with the side chains of H150, N154, and the backbone of S201. We also visualized unexpected substrate-enzyme interactions at the non-essential P2/P3 residues. These "extra" interactions foster potent rhomboid inhibition in living cells, thereby opening avenues for rational design of selective rhomboid inhibitors. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Direct and two-stage data analysis procedures based on PCA, PLS-DA and ANN for ISE-based electronic tongue-Effect of supervised feature extraction.

    Science.gov (United States)

    Ciosek, P; Brzózka, Z; Wróblewski, W; Martinelli, E; Di Natale, C; D'Amico, A

    2005-09-15

    A novel strategy of data analysis for artificial taste and odour systems is presented in this work. It is demonstrated that using a supervised method also in feature extraction phase enhances fruit juice classification capability of sensor array developed at Warsaw University of Technology. Comparison of direct processing (raw data processed by Artificial Neural Network (ANN), raw data processed by Partial Least Squares-Discriminant Analysis (PLS-DA)) and two-stage processing (Principal Components Analysis (PCA) outputs processed by ANN, PLS-DA outputs processed by ANN) is presented. It is shown that considerable increase of classification capability occurred in the case of the new method proposed by the authors.

  15. Evaluating Public Health Interventions: 3. The Two-Stage Design for Confounding Bias Reduction-Having Your Cake and Eating It Two.

    Science.gov (United States)

    Spiegelman, Donna; Rivera-Rodriguez, Claudia L; Haneuse, Sebastien

    2016-07-01

    In public health evaluations, confounding bias in the estimate of the intervention effect will typically threaten the validity of the findings. It is a common misperception that the only way to avoid this bias is to measure detailed, high-quality data on potential confounders for every intervention participant, but this strategy for adjusting for confounding bias is often infeasible. Rather than ignoring confounding altogether, the two-phase design and analysis-in which detailed high-quality confounding data are obtained among a small subsample-can be considered. We describe the two-stage design and analysis approach, and illustrate its use in the evaluation of an intervention conducted in Dar es Salaam, Tanzania, of an enhanced community health worker program to improve antenatal care uptake.

  16. Two-Stage Control Design of a Buck Converter/DC Motor System without Velocity Measurements via a Σ−Δ-Modulator

    Directory of Open Access Journals (Sweden)

    R. Silva-Ortigoza

    2013-01-01

    differential flatness property of the DC-motor model is exploited in order to propose a first-stage controller, which is designed to achieve the desired angular velocity trajectory. This controller provides the voltage profiles that must be tracked by the Buck converter. Then, a second-stage controller is meant to assure the aforementioned. This controller is based on flatness property of the Buck power converter model, which provides the input voltage to the DC motor. Due to the fact that the two-stage controller proposed uses the average model of the system, as a practical and effective implementation of this controller, a Σ − Δ-modulator is employed. Finally, in order to verify the control performance of this approach, numerical simulations are included.

  17. A two staged treatment procedure for the difficult to treat bladder neck contractures with concomitant incontinence. In the search of a solution to a complex problem

    Directory of Open Access Journals (Sweden)

    Ioannis Adamakis

    2015-09-01

    Full Text Available Objective: To examine the efficacy of a two staged treating strategy with the use of a non-permanent urethral ALLIUM® stent for the management of recurrent bladder neck stenosis and subsequently the use of an artificial sphincter AUS800® by AMS for the management of the incontinence. Materials and Methods: We progressively identified patients eligible for the study creating a population of cases with recurrent bladder neck stenosis and concomitant incontinence occurring after the last intervention for the stenosis. Efficacy for the treatment of the stenosis was defined as no recurrence both prior and post to the sphincter placement and efficacy for the treatment of the incontinence was defined as continence (0-1pads after the sphincter placement. Results and Limitations: 14 white males with a mean age of 66.21, ranging from 59 to 73 years consisted the population of the study. All patients had severe stress incontinence following the last transurethral resection. The efficacy of the treatment of the bladder neck stenosis was 93% (13/14 while the efficacy for the treatment of the incontinence was 100%. A single patient had a recurrent bladder neck stenosis after the artificial sphincter placement and was treated with transurethral resection using a long pediatric 13 F resectoscope at 12 months. Our limitations is the absence of a control group and the small number of patients enrolled, with a relatively short time of follow up. Conclusions: In our series we propose the use of a non-permanent urethral ALLIUM® stent for 6 months in order to control the growth of fibrotic scar tissue, a further 6 months follow up for recurrence, and then placement of an artificial sphincter. The results are very promising both on stabilizing the vesicourethral stenosis, and on patient safety and tolerability.

  18. RELEASE OF GENTAMICIN FROM CEMENT SPACERS IN TWO-STAGE PROCEDURES FOR HIP AND KNEE PROSTHETIC INFECTION: AN IN VIVO PHARMACOKINETIC STUDY WITH CLINICAL FOLLOW-UP.

    Science.gov (United States)

    Balato, G; Ascione, T; Rosa, D; Pagliano, P; Solarino, G; Moretti, B; Mariconda, M

    2015-01-01

    Eighteen patients undergoing two-stage exchange arthroplasty for infected total hip or knee arthroplasty using gentamicin-loaded bone cement spacers (80g bone cement, 2 g gentamicin and 2 g clindamycin) were studied. The concentration of gentamicin eluted from the spacers was assessed on samples of blood, urine, and drainage fluid that were collected from each patient at set intervals during the 48 hours following the first-stage surgery. The hip and knee cement spacers showed similar curve of release over the first postoperative hours (early peak followed by slow release), but the mean gentamicin concentration in the drainage fluid was higher in patients with hip spacers compared to patients with knee spacers (30.61±19.47 mg/L vs 17.43±13,63 mg/L, p less than 0.05). In patients with hip spacers, the mean, maximum, and minimum concentration of gentamicin was higher with respect to the minimum inhibitory concentration (MIC) break point for Staphylococcus spp, Pseudomonas Aeruginosa and Enterobacteriaceae throughout the first postoperative 48 h. Conversely, in 25% of patients with a knee spacer a drug concentration below the MIC break point for Gram negative bacteria was found in the drainage fluid after 12 h. Gentamicin levels in the blood samples were negligible over the entire time interval and were steadily well below the renal toxicity reference. The highest urinary concentration of gentamicin was observed between 4 and 9 h postoperatively. Subsequently, it gradually declined until 48 h. Clinically, the rate of cure was 100% at a mean follow-up of 113 weeks (range 90-182). Gentamicin-loaded cement spacers offer the advantage of achieving early high concentrations of the antibiotic directly at the site of infection but especially in the knee a systemic antibiotic therapy must be given as a complement to the spacer implantation to eradicate periprosthetic joint infection (PJI).

  19. Estimation of infection prevalence and sensitivity in a stratified two-stage sampling design employing highly specific diagnostic tests when there is no gold standard.

    Science.gov (United States)

    Miller, Ezer; Huppert, Amit; Novikov, Ilya; Warburg, Alon; Hailu, Asrat; Abbasi, Ibrahim; Freedman, Laurence S

    2015-11-10

    In this work, we describe a two-stage sampling design to estimate the infection prevalence in a population. In the first stage, an imperfect diagnostic test was performed on a random sample of the population. In the second stage, a different imperfect test was performed in a stratified random sample of the first sample. To estimate infection prevalence, we assumed conditional independence between the diagnostic tests and develop method of moments estimators based on expectations of the proportions of people with positive and negative results on both tests that are functions of the tests' sensitivity, specificity, and the infection prevalence. A closed-form solution of the estimating equations was obtained assuming a specificity of 100% for both tests. We applied our method to estimate the infection prevalence of visceral leishmaniasis according to two quantitative polymerase chain reaction tests performed on blood samples taken from 4756 patients in northern Ethiopia. The sensitivities of the tests were also estimated, as well as the standard errors of all estimates, using a parametric bootstrap. We also examined the impact of departures from our assumptions of 100% specificity and conditional independence on the estimated prevalence. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Influence of timing of hard palate repair in a two-stage procedure on early language development in Danish children with cleft palate

    DEFF Research Database (Denmark)

    Willadsen, Elisabeth

    2012-01-01

    Objective: to investigate the influence of timing of hard palate closure on early language development from 18 months to 3 years of age. Design: a prospective, randomized clinical trial. Participants: thirty-four children with UCLP with velum closure at 4 months of age, and hard palate closure...... were transcribed according to the International Phonetic Alphabet. At 36 months a single word naming test was administered. Results: at 18 months, the LateHPU group produced fewer labial stops and more velar stops than the Early HPR group. Unlike the Early HPR group, the LateHPU group produced fewer...

  1. Coal pillar design procedures

    CSIR Research Space (South Africa)

    York, G

    2000-03-01

    Full Text Available . The 99 per cent confidence interval for the in situ contact friction angle is 21.0° to 24.8°. The results of these investigations have been put together to form the basis of a new methodology for pillar design. A pillar design flowchart has been... calculated using the Salamon & Munro equation and after adjusting for the effect of jointing................52 Figure 2-2 Graph showing the effect of discontinuity orientation and frequency on the strength of pillars with a width to height ratio of 2.0...

  2. Two-stage tubularized transverse preputial island flap and two-stage urethral plate reconstruction procedures in the treatment of severe hypospadias%分期管形包皮岛状皮瓣术式与分期尿道板重建卷管术式治疗重度尿道下裂的疗效比较

    Institute of Scientific and Technical Information of China (English)

    田军; 张潍平; 孙宁; 谢向辉; 李明磊; 宋宏程; 李宁; 黄澄如

    2016-01-01

    Objective To compare the treatment efficacy of severe hypospadias between two-stage urethral plate reconstruction procedure and two-stage tubularized transverse preputial island flap procedure. Methods From 2010 December to 2014 December, we retrospectively analyzed 82 cases with severe hypospadias, using two-stage urethral plate reconstruction and two-stage tubularized transverse preputial island flap urethroplasty, respectively.Their mean age in the first operation was 2.4 years, ranged from 2 to 3 years.Hypospadias were penoscrotal type in 32 cases, perineal type in 50 cases.In group A, 42 cases, including penoscrotal type in 15 cases, perineal type in 27 cases, with urethral plate reconstruction procedure underwent two-stage urethroplasty.The transected ventral penile urethral plate and to strip the ventral fibrous tissue were needed in correction of chordee of penis.The patients in group A were underwent the second urethroplasty with urethral plate reconstruction procedure 6-12 months later.In group B, 40 cases,including penoscrotal type in 17 cases, perineal type in 23 cases, who underwent one stage operation in the correction of chordee of penis, only with tubularized preputial island flap forming the part of the urethra.The patients in group B were underwent the second urethroplasty 6 ~12 months later.Results Patients were followed up for 1 to 5 years, mean 3.5 years.No recurrence of penis chordee was noticed.In group A, 6 cases (14.3%) had postoperative fistula.The second fistula repairing was perform 6 to 12 months after the second stage operation.However, still 3 cases were noticed the fistula recurrence, which was cured after the fourth operation.In group B, 3 cases (7.5%) developed fistula, which appeared in the second urethroplasty (P<0.01).They were all treated after the second repairing procedure.In group A, 4 cases were noticed urethral stricture, the urethral stricture rate was 9.5%.The stricture occurred 1 to 3 months after the second operation

  3. Influence of timing of hard palate repair in a two-stage procedure on early language development in Danish children with cleft palate

    DEFF Research Database (Denmark)

    Willadsen, Elisabeth

    2012-01-01

    Objective: to investigate the influence of timing of hard palate closure on early language development from 18 months to 3 years of age. Design: a prospective, randomized clinical trial. Participants: thirty-four children with UCLP with velum closure at 4 months of age, and hard palate closure...... vocalizations, consonants, and consonants permissible in word-initial position than the Early HPR group. In addition, both cleft palate groups had a smaller productive vocabulary than the Control group, but unlike the EarlyHPR group, the LateHPU group produced a smaller number of word tokens in social...... language development in cleft palate children. Key words: cleft palate, phonological development, lexical development, surgical timing....

  4. Design Procedure for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Tjelflaat, Per Olaf

    Mechanical and natural ventilation systems have developed separately during many years. The natural next step in this development is development of ventilation concepts that utilises and combines the best features from each system into a new type of ventilation system - Hybrid Ventilation....... Buildings with hybrid ventilation often include other sustainable technologies and an energy optimisation requires an integrated approach in the design of the building and its mechanical systems. Therefore, the hybrid ventilation design procedure differs from the design procedure for conventional HVAC....... The first ideas on a design procedure for hybrid ventilation is presented and the different types of design methods, that is needed in different phases of the design process, is discussed....

  5. Simulation, design and proof-of-concept of a two-stage continuous hydrothermal flow synthesis reactor for synthesis of functionalized nano-sized inorganic composite materials

    DEFF Research Database (Denmark)

    Zielke, Philipp; Xu, Yu; Simonsen, Søren Bredmose

    2016-01-01

    Computational fluid dynamics simulations were employed to evaluate several mixer geometries for a novel two-stage continuous hydrothermal flow synthesis reactor. The addition of a second stage holds the promise of allowing the synthesis of functionalized nano-materials as for example core...

  6. Two-stage sampling for acceptance testing

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, C.L.; Bryan, M.F.

    1992-09-01

    Sometimes a regulatory requirement or a quality-assurance procedure sets an allowed maximum on a confidence limit for a mean. If the sample mean of the measurements is below the allowed maximum, but the confidence limit is above it, a very widespread practice is to increase the sample size and recalculate the confidence bound. The confidence level of this two-stage procedure is rarely found correctly, but instead is typically taken to be the nominal confidence level, found as if the final sample size had been specified in advance. In typical settings, the correct nominal [alpha] should be between the desired P(Type I error) and half that value. This note gives tables for the correct a to use, some plots of power curves, and an example of correct two-stage sampling.

  7. Two-stage sampling for acceptance testing

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, C.L.; Bryan, M.F.

    1992-09-01

    Sometimes a regulatory requirement or a quality-assurance procedure sets an allowed maximum on a confidence limit for a mean. If the sample mean of the measurements is below the allowed maximum, but the confidence limit is above it, a very widespread practice is to increase the sample size and recalculate the confidence bound. The confidence level of this two-stage procedure is rarely found correctly, but instead is typically taken to be the nominal confidence level, found as if the final sample size had been specified in advance. In typical settings, the correct nominal {alpha} should be between the desired P(Type I error) and half that value. This note gives tables for the correct a to use, some plots of power curves, and an example of correct two-stage sampling.

  8. Designing Flightdeck Procedures: Literature Resources

    Science.gov (United States)

    Feldman, Jolene; Barshi, Immanuel; Degani, Asaf; Loukopoulou, Loukia; Mauro, Robert

    2017-01-01

    This technical publication contains the titles, abstracts, summaries, descriptions, and/or annotations of available literature sources on procedure design and development, requirements, and guidance. It is designed to provide users with an easy access to available resources on the topic of procedure design, and with a sense of the contents of these sources. This repository of information is organized into the following publication sources: Research (e.g., journal articles, conference proceedings), Manufacturers' (e.g., operation manuals, newsletters), and Regulatory and/or Government (e.g., advisory circulars, reports). An additional section contains synopses of Accident/Incident Reports involving procedures. This work directly supports a comprehensive memorandum by Barshi, Mauro, Degani, & Loukopoulou (2016) that summarizes the results of a multi-year project, partially funded by the FAA, to develop technical reference materials that support guidance on the process of developing cockpit procedures (see "Designing Flightdeck Procedures" https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160013263.pdf). An extensive treatment of this topic is presented in a forthcoming book by the same authors.

  9. Two-Stage Modelling Of Random Phenomena

    Science.gov (United States)

    Barańska, Anna

    2015-12-01

    The main objective of this publication was to present a two-stage algorithm of modelling random phenomena, based on multidimensional function modelling, on the example of modelling the real estate market for the purpose of real estate valuation and estimation of model parameters of foundations vertical displacements. The first stage of the presented algorithm includes a selection of a suitable form of the function model. In the classical algorithms, based on function modelling, prediction of the dependent variable is its value obtained directly from the model. The better the model reflects a relationship between the independent variables and their effect on the dependent variable, the more reliable is the model value. In this paper, an algorithm has been proposed which comprises adjustment of the value obtained from the model with a random correction determined from the residuals of the model for these cases which, in a separate analysis, were considered to be the most similar to the object for which we want to model the dependent variable. The effect of applying the developed quantitative procedures for calculating the corrections and qualitative methods to assess the similarity on the final outcome of the prediction and its accuracy, was examined by statistical methods, mainly using appropriate parametric tests of significance. The idea of the presented algorithm has been designed so as to approximate the value of the dependent variable of the studied phenomenon to its value in reality and, at the same time, to have it "smoothed out" by a well fitted modelling function.

  10. Residential Two-Stage Gas Furnaces - Do They Save Energy?

    Energy Technology Data Exchange (ETDEWEB)

    Lekov, Alex; Franco, Victor; Lutz, James

    2006-05-12

    Residential two-stage gas furnaces account for almost a quarter of the total number of models listed in the March 2005 GAMA directory of equipment certified for sale in the United States. Two-stage furnaces are expanding their presence in the market mostly because they meet consumer expectations for improved comfort. Currently, the U.S. Department of Energy (DOE) test procedure serves as the method for reporting furnace total fuel and electricity consumption under laboratory conditions. In 2006, American Society of Heating Refrigeration and Air-conditioning Engineers (ASHRAE) proposed an update to its test procedure which corrects some of the discrepancies found in the DOE test procedure and provides an improved methodology for calculating the energy consumption of two-stage furnaces. The objectives of this paper are to explore the differences in the methods for calculating two-stage residential gas furnace energy consumption in the DOE test procedure and in the 2006 ASHRAE test procedure and to compare test results to research results from field tests. Overall, the DOE test procedure shows a reduction in the total site energy consumption of about 3 percent for two-stage compared to single-stage furnaces at the same efficiency level. In contrast, the 2006 ASHRAE test procedure shows almost no difference in the total site energy consumption. The 2006 ASHRAE test procedure appears to provide a better methodology for calculating the energy consumption of two-stage furnaces. The results indicate that, although two-stage technology by itself does not save site energy, the combination of two-stage furnaces with BPM motors provides electricity savings, which are confirmed by field studies.

  11. Classification in two-stage screening.

    Science.gov (United States)

    Longford, Nicholas T

    2015-11-10

    Decision theory is applied to the problem of setting thresholds in medical screening when it is organised in two stages. In the first stage that involves a less expensive procedure that can be applied on a mass scale, an individual is classified as a negative or a likely positive. In the second stage, the likely positives are subjected to another test that classifies them as (definite) positives or negatives. The second-stage test is more accurate, but also more expensive and more involved, and so there are incentives to restrict its application. Robustness of the method with respect to the parameters, some of which have to be set by elicitation, is assessed by sensitivity analysis.

  12. Two stage gear tooth dynamics program

    Science.gov (United States)

    Boyd, Linda S.

    1989-01-01

    The epicyclic gear dynamics program was expanded to add the option of evaluating the tooth pair dynamics for two epicyclic gear stages with peripheral components. This was a practical extension to the program as multiple gear stages are often used for speed reduction, space, weight, and/or auxiliary units. The option was developed for either stage to be a basic planetary, star, single external-external mesh, or single external-internal mesh. The two stage system allows for modeling of the peripherals with an input mass and shaft, an output mass and shaft, and a connecting shaft. Execution of the initial test case indicated an instability in the solution with the tooth paid loads growing to excessive magnitudes. A procedure to trace the instability is recommended as well as a method of reducing the program's computation time by reducing the number of boundary condition iterations.

  13. LOGISTICS SCHEDULING: ANALYSIS OF TWO-STAGE PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Yung-Chia CHANG; Chung-Yee LEE

    2003-01-01

    This paper studies the coordination effects between stages for scheduling problems where decision-making is a two-stage process. Two stages are considered as one system. The system can be a supply chain that links two stages, one stage representing a manufacturer; and the other, a distributor.It also can represent a single manufacturer, while each stage represents a different department responsible for a part of operations. A problem that jointly considers both stages in order to achieve ideal overall system performance is defined as a system problem. In practice, at times, it might not be feasible for the two stages to make coordinated decisions due to (i) the lack of channels that allow decision makers at the two stages to cooperate, and/or (ii) the optimal solution to the system problem is too difficult (or costly) to achieve.Two practical approaches are applied to solve a variant of two-stage logistic scheduling problems. The Forward Approach is defined as a solution procedure by which the first stage of the system problem is solved first, followed by the second stage. Similarly, the Backward Approach is defined as a solution procedure by which the second stage of the system problem is solved prior to solving the first stage. In each approach, two stages are solved sequentially and the solution generated is treated as a heuristic solution with respect to the corresponding system problem. When decision makers at two stages make decisions locally without considering consequences to the entire system,ineffectiveness may result - even when each stage optimally solves its own problem. The trade-off between the time complexity and the solution quality is the main concern. This paper provides the worst-case performance analysis for each approach.

  14. The construction of two-stage tests

    NARCIS (Netherlands)

    Adema, Jos J.

    1988-01-01

    Although two-stage testing is not the most efficient form of adaptive testing, it has some advantages. In this paper, linear programming models are given for the construction of two-stage tests. In these models, practical constraints with respect to, among other things, test composition, administrat

  15. Two-stage local M-estimation of additive models

    Institute of Scientific and Technical Information of China (English)

    JIANG JianCheng; LI JianTao

    2008-01-01

    This paper studies local M-estimation of the nonparametric components of additive models. A two-stage local M-estimation procedure is proposed for estimating the additive components and their derivatives. Under very mild conditions, the proposed estimators of each additive component and its derivative are jointly asymptotically normal and share the same asymptotic distributions as they would be if the other components were known. The established asymptotic results also hold for two particular local M-estimations: the local least squares and least absolute deviation estimations. However,for general two-stage local M-estimation with continuous and nonlinear ψ-functions, its implementation is time-consuming. To reduce the computational burden, one-step approximations to the two-stage local M-estimators are developed. The one-step estimators are shown to achieve the same efficiency as the fully iterative two-stage local M-estimators, which makes the two-stage local M-estimation more feasible in practice. The proposed estimators inherit the advantages and at the same time overcome the disadvantages of the local least-squares based smoothers. In addition, the practical implementation of the proposed estimation is considered in details. Simulations demonstrate the merits of the two-stage local M-estimation, and a real example illustrates the performance of the methodology.

  16. Two-stage local M-estimation of additive models

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper studies local M-estimation of the nonparametric components of additive models.A two-stage local M-estimation procedure is proposed for estimating the additive components and their derivatives.Under very mild conditions,the proposed estimators of each additive component and its derivative are jointly asymptotically normal and share the same asymptotic distributions as they would be if the other components were known.The established asymptotic results also hold for two particular local M-estimations:the local least squares and least absolute deviation estimations.However,for general two-stage local M-estimation with continuous and nonlinear ψ-functions,its implementation is time-consuming.To reduce the computational burden,one-step approximations to the two-stage local M-estimators are developed.The one-step estimators are shown to achieve the same effciency as the fully iterative two-stage local M-estimators,which makes the two-stage local M-estimation more feasible in practice.The proposed estimators inherit the advantages and at the same time overcome the disadvantages of the local least-squares based smoothers.In addition,the practical implementation of the proposed estimation is considered in details.Simulations demonstrate the merits of the two-stage local M-estimation,and a real example illustrates the performance of the methodology.

  17. Composite likelihood and two-stage estimation in family studies

    DEFF Research Database (Denmark)

    Andersen, Elisabeth Anne Wreford

    2004-01-01

    In this paper register based family studies provide the motivation for linking a two-stage estimation procedure in copula models for multivariate failure time data with a composite likelihood approach. The asymptotic properties of the estimators in both parametric and semi-parametric models are d...

  18. 基于两段式水煤浆气化的IGCC系统变工况特性%Off-design Characteristics of IGCC System Based on Two-stage Coal-slurry Gasification Technology

    Institute of Scientific and Technical Information of China (English)

    刘耀鑫; 吴少华; 李振中; 王阳

    2012-01-01

    The integrated gasification combined cycle system(IGCC) is often operated at off-design condition.In order to learn the off-design characteristics of IGCC,the software ThermoFlex was used to establish the model of a 200 MW integrated gasification combined cycle(IGCC) system based on the two-stage coal-slurry gasification technology.The effects of gas turbine load,air separation unit integrated coefficient(Xas),atmosphere temperature and atmosphere pressure on the performance of IGCC system were investigated.The results show that gross and net electric efficiency increases at first and then decreases with atmosphere temperature increasing or gas turbine load decreasing.The gross electric efficiency decreases when the air separation unit integrated coefficient increases.Atmosphere pressure has little effect on system efficiency.The application of two-stage coal-slurry gasification technology has good availability to improve IGCC system performance under the above running conditions.The results will provide reference for design and operation of the IGCC power plant.%整体煤气化联合循环(integrated gasification combinedcycle,IGCC)机组在一定情况下处于非设计工况运行。为了研究IGCC系统变工况特性,采用ThermoFlex软件建立基于两段式水煤浆气化技术的200 MW级整体煤气化联合循环系统模型,主要考查燃气轮机负荷、整体空分系数Xas、大气温度、大气压力对系统性能的影响。研究结果表明,降低燃气轮机负荷或者提高大气温度系统效率均呈先升高而后降低的趋势。整体空分系数Xas增加,机组发电效率降低。大气压力对系统效率影响较小。上述条件下采用两段水煤浆气化技术,系统性能可以得到有效改善。研究结果可为采用两段式水煤浆气化技术的IGCC系统的设计、运行提供参考。

  19. Diesel with low sulfur content and high cetane number produced by two stages hydrotreating procedures; Diesel com baixos teores de enxofre e alto numero de cetano a partir de hidrotratamento em dois estagios

    Energy Technology Data Exchange (ETDEWEB)

    Zotin, J.L.; Pacheco, M.E.; Souza, V.P.; Belato, D.; Silva, R.M.S. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    According to the Brazilian specifications for diesel, lower sulfur content and higher cetane number can be expected in the near future, leading to an increased capacity of hydrotreating processes. PETROBRAS has proved technology for hydrotreating processes with 8 high pressure single stage units in operation. However, the production of ultra low sulfur diesel with high cetane number may require two stages processes, with conventional hydrotreating in the first step and deep aromatic saturation (HDA), with increase in the cetane number, in the second one. In this approach, noble metal catalysts, which are more active for hydrogenation but more sensitive to sulfur and nitrogen poisoning, can be used in the second stage. In the present work, the 2 stages approach was studied for maximizing cetane number of Brazilian gasoils. The influence of operating variables and the inhibition effect by sulfur and nitrogen were analyzed. Diesel with sulfur content below 10 ppm and high aromatic conversions at relatively mild conditions were obtained with noble metal catalysts, with a cetane number increase up to 6 points in the second stage. Sulfur compounds have a stronger inhibition effect than basic nitrogen compounds on hydrogenation reaction rates, but a synergetic effect was observed when both contaminants were present in high concentrations. (author)

  20. Simplified design procedure for base isolation system

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, Mineo; Tada, Hideyuki [Fukuoka Univ. (Japan). Faculty of Engineering

    1995-12-01

    This paper presents a simplified design procedure which incorporates an existing response prediction method for base isolated buildings into design methods for isolation devices (rubber bearings and hysteresis dampers). The procedure enables a designer to easily identify the relationship between tile seismic behavior of base-isolated buildings and the characteristics of isolation devices. The prediction method, proposed by Prof. Akiyama, is based on energy balance between the total input seismic energy and the energy absorbed by the isolation devices. The method is very accurate. The design methods for devices were developed by authors based on experimental and finite element analysis results.

  1. Design Procedure of 4-Bladed Propeller

    African Journals Online (AJOL)

    PROF. O. E. OSUAGWU

    2013-09-01

    Sep 1, 2013 ... experiments with small–scale propeller mode were made in ... experiments were used to verify the design calculations like ... extent, in their aim to satisfy a particular set of .... 5.5knots. 2. = Brake power B. P from equation 2 is calculated as follow: ..... A step by step design procedure for a 4-bladed propeller ...

  2. Reassessment of coal pillar design procedure

    CSIR Research Space (South Africa)

    Madden, BJ

    1995-12-01

    Full Text Available The SIMRAC project COL 021A entitled “a reassessment of coal pillar design procedures” set out to achieve a coal pillar design procedure that takes cognisance of different geological and structural factors as well as the influence...

  3. Dynamic Modelling of the Two-stage Gasification Process

    DEFF Research Database (Denmark)

    Gøbel, Benny; Henriksen, Ulrik B.; Houbak, Niels

    1999-01-01

    A two-stage gasification pilot plant was designed and built as a co-operative project between the Technical University of Denmark and the company REKA.A dynamic, mathematical model of the two-stage pilot plant was developed to serve as a tool for optimising the process and the operating conditions...... of the gasification plant.The model consists of modules corresponding to the different elements in the plant. The modules are coupled together through mass and heat conservation.Results from the model are compared with experimental data obtained during steady and unsteady operation of the pilot plant. A good...

  4. Design Procedure for Compact Folded Waveguide Filters

    DEFF Research Database (Denmark)

    Dong, Yunfeng; Johansen, Tom Keinicke; Zhurbenko, Vitaliy;

    Waveguide filters are widely used in communication systems due to low losses and high power handling capabilities. One drawback of the conventional waveguide filters is their large size, especially for low-frequency and high-order realizations. It has been shown that the footprint of conventional...... waveguide resonators can be reduced to one quarter by folding the electric and magnetic fields inside the cavity (J. S. Hong, Microwave Symposium Digest, 2004, Vol. 1, pp. 213-216). This paper presents a novel systematic procedure for designing compact low-loss bandpass filters by using folded waveguide...... resonators. As a design example, a scaled version of a filter specified for a TETRA (Terrestrial Trunked Radio) system has been considered. The folded waveguide filter is designed to fulfil specific requirements, and the design procedure can be easily applied to other folded waveguide filter designs...

  5. Reliability based fatigue design and maintenance procedures

    Science.gov (United States)

    Hanagud, S.

    1977-01-01

    A stochastic model has been developed to describe a probability for fatigue process by assuming a varying hazard rate. This stochastic model can be used to obtain the desired probability of a crack of certain length at a given location after a certain number of cycles or time. Quantitative estimation of the developed model was also discussed. Application of the model to develop a procedure for reliability-based cost-effective fail-safe structural design is presented. This design procedure includes the reliability improvement due to inspection and repair. Methods of obtaining optimum inspection and maintenance schemes are treated.

  6. FREE GRAFT TWO-STAGE URETHROPLASTY FOR HYPOSPADIAS REPAIR

    Institute of Scientific and Technical Information of China (English)

    Zhong-jin Yue; Ling-jun Zuo; Jia-ji Wang; Gan-ping Zhong; Jian-ming Duan; Zhi-ping Wang; Da-shan Qin

    2005-01-01

    Objective To evaluate the effectiveness of free graft transplantation two-stage urethroplasty for hypospadias repair.Methods Fifty-eight cases with different types of hypospadias including 10 subcoronal, 36 penile shaft, 9 scrotal, and 3 perineal were treated with free full-thickness skin graft or (and) buccal mucosal graft transplantation two-stage urethroplasty. Of 58 cases, 45 were new cases, 13 had history of previous failed surgeries. Operative procedure included two stages: the first stage is to correct penile curvature (chordee), prepare transplanting bed, harvest and prepare full-thickness skin graft, buccal mucosal graft, and perform graft transplantation. The second stage is to complete urethroplasty and glanuloplasty.Results After the first stage operation, 56 of 58 cases (96.6%) were successful with grafts healing well, another 2foreskin grafts got gangrened. After the second stage operation on 56 cases, 5 cases failed with newly formed urethras opened due to infection, 8 cases had fistulas, 43 (76.8%) cases healed well.Conclusions Free graft transplantation two-stage urethroplasty for hypospadias repair is a kind of effective treatment with broad indication, comparatively high success rate, less complicationsand good cosmatic results, indicative of various types of hypospadias repair.

  7. High Performance Gasification with the Two-Stage Gasifier

    DEFF Research Database (Denmark)

    Gøbel, Benny; Hindsgaul, Claus; Henriksen, Ulrik Birk

    2002-01-01

    Based on more than 15 years of research and practical experience, the Technical University of Denmark (DTU) and COWI Consulting Engineers and Planners AS present the two-stage gasification process, a concept for high efficiency gasification of biomass producing negligible amounts of tars. In the ......Based on more than 15 years of research and practical experience, the Technical University of Denmark (DTU) and COWI Consulting Engineers and Planners AS present the two-stage gasification process, a concept for high efficiency gasification of biomass producing negligible amounts of tars....... In the two-stage gasification concept, the pyrolysis and the gasification processes are physical separated. The volatiles from the pyrolysis are partially oxidized, and the hot gases are used as gasification medium to gasify the char. Hot gases from the gasifier and a combustion unit can be used for drying...... a cold gas efficiency exceeding 90% is obtained. In the original design of the two-stage gasification process, the pyrolysis unit consists of a screw conveyor with external heating, and the char unit is a fixed bed gasifier. This design is well proven during more than 1000 hours of testing with various...

  8. Two Stage Gear Tooth Dynamics Program

    Science.gov (United States)

    1989-08-01

    cordi - tions and associated iteration prooedure become more complex. This is due to both the increased number of components and to the time for a...solved for each stage in the two stage solution . There are (3 + ntrrber of planets) degrees of freedom fcr eacb stage plus two degrees of freedom...should be devised. It should be noted that this is not minor task. In general, each stage plus an input or output shaft will have 2 times (4 + number

  9. Chipless RFID design procedure and detection techniques

    CERN Document Server

    Rezaiesarlak, Reza

    2015-01-01

    This book examines the design of chipless RFID systems. The authors begin with the historical development of wireless identification systems and finally arrive at a representation of the chipless RFID system as a block diagram illustration. Chapter 2 is devoted to the theoretical bases for the design of chipless RFID tags and detection techniques in the reader. A rigorous mathematical formulation is presented based on the singularity expansion method (SEM) and characteristic mode theory (CMT) in order to study the scattered fields from an object in a general form. Th e authors attempt to explain some physical concepts behind the mathematical descriptions of the theories in this chapter. In Chapter 3, two design procedures based on complex natural resonance and CMT are presented for the design of the chipless RFID tag. By studying the effects of structural parameters on radiation and resonant behaviors of the tag, some design conclusions are presented in this chapter. Chapter 4 is dedicated to the time-frequen...

  10. Procedure Design to Fulfill Quality Management System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the application of the principle of PDCA, and dr awing on the experience of the process methods of the ISO9000 and the system met hods of management, the author analyses the basic requirement to fulfill quality management system in enterprises. Then the author inquires into the procedure t o establish the efficiency quality management system. Finally four stages (plan, do, check, action) and eight steps (decision, plan, analyze, design, do, check, improve, fulfill) are put forward to fulfill qualit...

  11. Condensate from a two-stage gasifier

    DEFF Research Database (Denmark)

    Bentzen, Jens Dall; Henriksen, Ulrik Birk; Hindsgaul, Claus

    2000-01-01

    that the organic compounds and the inhibition effect are very low even before treatment with activated carbon. The moderate inhibition effect relates to a high content of ammonia in the condensate. The nitrifiers become tolerant to the condensate after a few weeks of exposure. The level of organic compounds......Condensate, produced when gas from downdraft biomass gasifier is cooled, contains organic compounds that inhibit nitrifiers. Treatment with activated carbon removes most of the organics and makes the condensate far less inhibitory. The condensate from an optimised two-stage gasifier is so clean...

  12. Two Stage Sibling Cycle Compressor/Expander.

    Science.gov (United States)

    1994-02-01

    vol. 5, p. 424. 11. L. Bauwens and M.P. Mitchell, " Regenerator Analysis: Validation of the MS*2 Stirling Cycle Code," Proc. XVIIIth International...PL-TR--94-1051 PL-TR-- 94-1051 TWO STAGE SIBLING CYCLE COMPRESSOR/EXPANDER Matthew P. Mitchell . Mitchell/ Stirling Machines/Systems, Inc. No\\ 1995...ty. THIS PAGE IS UNCLASSIFIED PL-TR-94-1051 This final report was prepared byMitchell/ Stirling Machines/Systems, Inc., Berkeley, CA under Contract

  13. Measuring the Learning from Two-Stage Collaborative Group Exams

    CERN Document Server

    Ives, Joss

    2014-01-01

    A two-stage collaborative exam is one in which students first complete the exam individually, and then complete the same or similar exam in collaborative groups immediately afterward. To quantify the learning effect from the group component of these two-stage exams in an introductory Physics course, a randomized crossover design was used where each student participated in both the treatment and control groups. For each of the two two-stage collaborative group midterm exams, questions were designed to form matched near-transfer pairs with questions on an end-of-term diagnostic which was used as a learning test. For learning test questions paired with questions from the first midterm, which took place six to seven weeks before the learning test, an analysis using a mixed-effects logistic regression found no significant differences in learning-test performance between the control and treatment group. For learning test questions paired with questions from the second midterm, which took place one to two weeks prio...

  14. Simultaneous bile duct and portal venous branch ligation in two-stage hepatectomy

    Institute of Scientific and Technical Information of China (English)

    Hiroya Iida; Chiaki Yasui; Tsukasa Aihara; Shinichi Ikuta; Hidenori Yoshie; Naoki Yamanaka

    2011-01-01

    Hepatectomy is an effective surgical treatment for multiple bilobar liver metastases from colon cancer; however, one of the primary obstacles to completing surgical resection for these cases is an insufficient volume of the future remnant liver, which may cause postoperative liver failure. To induce atrophy of the unilateral lobe and hypertrophy of the future remnant liver, procedures to occlude the portal vein have been conventionally used prior to major hepatectomy. We report a case of a 50-year-old woman in whom two-stage hepatectomy was performed in combination with intraoperative ligation of the portal vein and the bile duct of the right hepatic lobe. This procedure was designed to promote the atrophic effect on the right hepatic lobe more effectively than the conventional technique, and to the best of our knowledge, it was used for the first time in the present case. Despite successful induction of liver volume shift as well as the following procedure, the patient died of subsequent liver failure after developing recurrent tumors. We discuss the first case in which simultaneous ligation of the portal vein and the biliary system was successfully applied as part of the first step of two-stage hepatectomy.

  15. Research and design of two - stage defensive system in network security%一种网络安全两级防御系统的研究与设计

    Institute of Scientific and Technical Information of China (English)

    杨玉新

    2012-01-01

    传统的单一防御产品难以构建一个安全的网络防御系统,在参照一些先进的网络安全解决方案的基础上,提出了一种两级防御体系结构模型。在整个防御系统中,设计了在Linux环境下以基于网络的入侵防御系统(NIPS:Network—based Intrusion Prevention System)为第一级入侵防御系统,以主机安全代理为第二级防御系统。两系统都与管理中心保持有密切的通信机制,其中主机安全代理不仅以软件的方式运行在内部网络的各个主机中,也可以安装在远程用户的便携机和托管服务器上。%The traditional single defensive products are difficult to construct a network security defense system. This paper propose a two - stage prevention system model by consulted advanced network security solutions, taking a network - based intrusion prevention system in Linux environment as the first stage and the host security agent system as the second stage. The two stages maintain close communication with the administration center, in which host security agent system not only operate in the various mainframe network by software, but also can be installed in the laptop and server care of remote users.

  16. A Two Stage Classification Approach for Handwritten Devanagari Characters

    CERN Document Server

    Arora, Sandhya; Nasipuri, Mita; Malik, Latesh

    2010-01-01

    The paper presents a two stage classification approach for handwritten devanagari characters The first stage is using structural properties like shirorekha, spine in character and second stage exploits some intersection features of characters which are fed to a feedforward neural network. Simple histogram based method does not work for finding shirorekha, vertical bar (Spine) in handwritten devnagari characters. So we designed a differential distance based technique to find a near straight line for shirorekha and spine. This approach has been tested for 50000 samples and we got 89.12% success

  17. Two-Stage Eagle Strategy with Differential Evolution

    CERN Document Server

    Yang, Xin-She

    2012-01-01

    Efficiency of an optimization process is largely determined by the search algorithm and its fundamental characteristics. In a given optimization, a single type of algorithm is used in most applications. In this paper, we will investigate the Eagle Strategy recently developed for global optimization, which uses a two-stage strategy by combing two different algorithms to improve the overall search efficiency. We will discuss this strategy with differential evolution and then evaluate their performance by solving real-world optimization problems such as pressure vessel and speed reducer design. Results suggest that we can reduce the computing effort by a factor of up to 10 in many applications.

  18. Runway Operations Planning: A Two-Stage Heuristic Algorithm

    Science.gov (United States)

    Anagnostakis, Ioannis; Clarke, John-Paul

    2003-01-01

    The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. From the perspective of departures, ROP solutions are aircraft departure schedules developed by optimally allocating runway time for departures given the time required for arrivals and crossings. In addition to the obvious objective of maximizing throughput, other objectives, such as guaranteeing fairness and minimizing environmental impact, can also be incorporated into the ROP solution subject to constraints introduced by Air Traffic Control (ATC) procedures. This paper introduces a two stage heuristic algorithm for solving the Runway Operations Planning (ROP) problem. In the first stage, sequences of departure class slots and runway crossings slots are generated and ranked based on departure runway throughput under stochastic conditions. In the second stage, the departure class slots are populated with specific flights from the pool of available aircraft, by solving an integer program with a Branch & Bound algorithm implementation. Preliminary results from this implementation of the two-stage algorithm on real-world traffic data are presented.

  19. Two-Stage Heuristic Algorithm for Aircraft Recovery Problem

    Directory of Open Access Journals (Sweden)

    Cheng Zhang

    2017-01-01

    Full Text Available This study focuses on the aircraft recovery problem (ARP. In real-life operations, disruptions always cause schedule failures and make airlines suffer from great loss. Therefore, the main objective of the aircraft recovery problem is to minimize the total recovery cost and solve the problem within reasonable runtimes. An aircraft recovery model (ARM is proposed herein to formulate the ARP and use feasible line of flights as the basic variables in the model. We define the feasible line of flights (LOFs as a sequence of flights flown by an aircraft within one day. The number of LOFs exponentially grows with the number of flights. Hence, a two-stage heuristic is proposed to reduce the problem scale. The algorithm integrates a heuristic scoring procedure with an aggregated aircraft recovery model (AARM to preselect LOFs. The approach is tested on five real-life test scenarios. The computational results show that the proposed model provides a good formulation of the problem and can be solved within reasonable runtimes with the proposed methodology. The two-stage heuristic significantly reduces the number of LOFs after each stage and finally reduces the number of variables and constraints in the aircraft recovery model.

  20. Composite likelihood and two-stage estimation in family studies

    DEFF Research Database (Denmark)

    Andersen, Elisabeth Anne Wreford

    2002-01-01

    Composite likelihood; Two-stage estimation; Family studies; Copula; Optimal weights; All possible pairs......Composite likelihood; Two-stage estimation; Family studies; Copula; Optimal weights; All possible pairs...

  1. On the robustness of two-stage estimators

    KAUST Repository

    Zhelonkin, Mikhail

    2012-04-01

    The aim of this note is to provide a general framework for the analysis of the robustness properties of a broad class of two-stage models. We derive the influence function, the change-of-variance function, and the asymptotic variance of a general two-stage M-estimator, and provide their interpretations. We illustrate our results in the case of the two-stage maximum likelihood estimator and the two-stage least squares estimator. © 2011.

  2. Alignment and characterization of the two-stage time delay compensating XUV monochromator

    CERN Document Server

    Eckstein, Martin; Kubin, Markus; Yang, Chung-Hsin; Frassetto, Fabio; Poletto, Luca; Vrakking, Marc J J; Kornilov, Oleg

    2016-01-01

    We present the design, implementation and alignment procedure for a two-stage time delay compensating monochromator. The setup spectrally filters the radiation of a high-order harmonic generation source providing wavelength-selected XUV pulses with a bandwidth of 300 to 600~meV in the photon energy range of 3 to 50~eV. XUV pulses as short as $12\\pm3$~fs are demonstrated. Transmission of the 400~nm (3.1~eV) light facilitates precise alignment of the monochromator. This alignment strategy together with the stable mechanical design of the motorized beamline components enables us to automatically scan the XUV photon energ in pump-probe experiments that require XUV beam pointing stability. The performance of the beamline is demonstrated by the generation of IR-assisted sidebands in XUV photoionization of argon atoms.

  3. Design procedure for optimizing CMOS low noise operational amplifiers

    Institute of Scientific and Technical Information of China (English)

    Li Zhiyuan; Ye Yizheng; Ma Jianguo

    2009-01-01

    This paper presents and experimentally verifies an optimized design procedure for a CMOS low noise operational amplifier.The design procedure focuses on the noise performance,which is the key requirement for low noise operational amplifiers.Based on the noise level and other specifications such as bandwidth,signal swing,slew rate,and power consumption,the device sizes and the biasing conditions are derived.In order to verify the proposed design procedure,a three-stage operational amplifier has been designed.The device parameters obtained from the proposed design procedure closely agree with the simulated results obtained by using HSPICE.

  4. A Two-Stage Waste Gasification Reactor for Mars In-Situ Resource Utilization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design, build, and test a two-stage waste processing reactor for space applications. Our proposed technology converts waste from space missions into...

  5. Two-stage reflective optical system for achromatic 10 nm x-ray focusing

    Science.gov (United States)

    Motoyama, Hiroto; Mimura, Hidekazu

    2015-12-01

    Recently, coherent x-ray sources have promoted developments of optical systems for focusing, imaging, and interferometers. In this paper, we propose a two-stage focusing optical system with the goal of achromatically focusing pulses from an x-ray free-electron laser (XFEL), with a focal width of 10 nm. In this optical system, the x-ray beam is expanded by a grazing-incidence aspheric mirror, and it is focused by a mirror that is shaped as a solid of revolution. We describe the design procedure and discuss the theoretical focusing performance. In theory, soft-XFEL lights can be focused to a 10 nm area without chromatic aberration and with high reflectivity; this creates an unprecedented power density of 1020 W cm-2 in the soft-x-ray range.

  6. DEVELOPMENT OF COLD CLIMATE HEAT PUMP USING TWO-STAGE COMPRESSION

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Rice, C Keith [ORNL; Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL

    2015-01-01

    This paper uses a well-regarded, hardware based heat pump system model to investigate a two-stage economizing cycle for cold climate heat pump applications. The two-stage compression cycle has two variable-speed compressors. The high stage compressor was modelled using a compressor map, and the low stage compressor was experimentally studied using calorimeter testing. A single-stage heat pump system was modelled as the baseline. The system performance predictions are compared between the two-stage and single-stage systems. Special considerations for designing a cold climate heat pump are addressed at both the system and component levels.

  7. DEVELOPMENT OF COLD CLIMATE HEAT PUMP USING TWO-STAGE COMPRESSION

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Rice, C Keith [ORNL; Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL

    2015-01-01

    This paper uses a well-regarded, hardware based heat pump system model to investigate a two-stage economizing cycle for cold climate heat pump applications. The two-stage compression cycle has two variable-speed compressors. The high stage compressor was modelled using a compressor map, and the low stage compressor was experimentally studied using calorimeter testing. A single-stage heat pump system was modelled as the baseline. The system performance predictions are compared between the two-stage and single-stage systems. Special considerations for designing a cold climate heat pump are addressed at both the system and component levels.

  8. Comparison of single-stage and a two-stage vertical flow constructed wetland systems for different load scenarios.

    Science.gov (United States)

    Langergraber, Guenter; Pressl, Alexander; Leroch, Klaus; Rohrhofer, Roland; Haberl, Raimund

    2010-01-01

    Constructed wetlands (CWs) are known to be robust wastewater treatment systems and are therefore very suitable for small villages and single households. When nitrification is required, vertical flow (VF) CWs are widely used. This contribution compares the behaviour and treatment efficiencies of a single-stage VF CW and a two-stage VF CW system under varying operating and loading conditions according to standardized testing procedures for small wastewater treatment plants as described in the European standard EN 12566-3. The single-stage VF CW is designed and operated according to the Austrian design standards with an organic load of 20 g COD m(-2) d(-1) (i.e. 4 m(2) per person equivalent (PE)) The two-stage VF CW system is operated with 40 g COD m(-2) d(-1) (i.e. 2 m(2) per PE). During the 48 week testing period the Austrian threshold effluent concentrations have not been exceeded in either system. The two-stage VF CW system showed to be more robust as compared to the single-stage VF CW especially during highly fluctuating loads at low temperatures.

  9. 40 CFR 240.201-2 - Recommended procedures: Design.

    Science.gov (United States)

    2010-07-01

    ... carcasses, automobile bodies, dewatered sludges from water treatment plants, and industrial process wastes. ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended procedures: Design. 240... § 240.201-2 Recommended procedures: Design. (a) Provision for storing, handling, and removing...

  10. Gas loading system for LANL two-stage gas guns

    Science.gov (United States)

    Gibson, Lee; Bartram, Brian; Dattelbaum, Dana; Lang, John; Morris, John

    2015-06-01

    A novel gas loading system was designed for the specific application of remotely loading high purity gases into targets for gas-gun driven plate impact experiments. The high purity gases are loaded into well-defined target configurations to obtain Hugoniot states in the gas phase at greater than ambient pressures. The small volume of the gas samples is challenging, as slight changing in the ambient temperature result in measurable pressure changes. Therefore, the ability to load a gas gun target and continually monitor the sample pressure prior to firing provides the most stable and reliable target fielding approach. We present the design and evaluation of a gas loading system built for the LANL 50 mm bore two-stage light gas gun. Targets for the gun are made of 6061 Al or OFHC Cu, and assembled to form a gas containment cell with a volume of approximately 1.38 cc. The compatibility of materials was a major consideration in the design of the system, particularly for its use with corrosive gases. Piping and valves are stainless steel with wetted seals made from Kalrez and Teflon. Preliminary testing was completed to ensure proper flow rate and that the proper safety controls were in place. The system has been used to successfully load Ar, Kr, Xe, and anhydrous ammonia with purities of up to 99.999 percent. The design of the system, and example data from the plate impact experiments will be shown. LA-UR-15-20521

  11. 二级驱动的串行TFT-LCD显示终端设计%Design of Serial TFT-LCD Display Terminal Based on Two-Stage Driving

    Institute of Scientific and Technical Information of China (English)

    石建国; 邓春健

    2011-01-01

    A kind of universal serial TFT-LCD display terminal with ATmegal28L as the 2nd driver is designed and implemented.SPI serial Flash is employed to store multiple sets of ASCII and GB2312 character matrix data and background images.High level display commands from external master controller could be received through RS232 or RS485 standard interface and trigger requested display operations.Actual applications reveal that this terminal could help to reduce display control burden for master controller and could be used as universal information output device for many kinds of microcontroller-based systems.%设计并实现了一种采用ATmegal28L作为二级驱动器的通用串行TFT-LCD显示终端,利用SPI串行Flash存储多套中英文字库和背景图片,对外提供RS232和RS485两种标准接口,可接收外部主控器串行发送的高级显示命令,实现其要求的显示效果.多个项目的应用实践表明,该显示终端有利于减轻主控器的显示处理负担,可作为多种单片机应用系统的通用信息输出设备.

  12. Design Transformations for Rule-based Procedural Modeling

    KAUST Repository

    Lienhard, Stefan

    2017-05-24

    We introduce design transformations for rule-based procedural models, e.g., for buildings and plants. Given two or more procedural designs, each specified by a grammar, a design transformation combines elements of the existing designs to generate new designs. We introduce two technical components to enable design transformations. First, we extend the concept of discrete rule switching to rule merging, leading to a very large shape space for combining procedural models. Second, we propose an algorithm to jointly derive two or more grammars, called grammar co-derivation. We demonstrate two applications of our work: we show that our framework leads to a larger variety of models than previous work, and we show fine-grained transformation sequences between two procedural models.

  13. Automated Procedure for Roll Pass Design

    Science.gov (United States)

    Lambiase, F.; Langella, A.

    2009-04-01

    The aim of this work has been to develop an automatic roll pass design method, capable of minimizing the number of roll passes. The adoption of artificial intelligence technologies, particularly expert systems, and a hybrid model for the surface profile evaluation of rolled bars, has allowed us to model the search for the minimal sequence with a tree path search. This approach permitted a geometrical optimization of roll passes while allowing automation of the roll pass design process. Moreover, the heuristic nature of the inferential engine contributes a great deal toward reducing search time, thus allowing such a system to be employed for industrial purposes. Finally, this new approach was compared with other recently developed automatic systems to validate and measure possible improvements among them.

  14. JSC Design and Procedural Standards, JSC-STD-8080

    Science.gov (United States)

    Punch, Danny T.

    2011-01-01

    This document provides design and procedural requirements appropriate for inclusion in specifications for any human spaceflight program, project, spacecraft, system, or end item. The term "spacecraft" as used in the standards includes launch vehicles, orbital vehicles, non-terrestrial surface vehicles, and modules. The standards are developed and maintained as directed by Johnson Space Center (JSC) Policy Directive JPD 8080.2, JSC Design and Procedural Standards for Human Space Flight Equipment. The Design and Procedural Standards contained in this manual represent human spacecraft design and operational knowledge applicable to a wide range of spaceflight activities. These standards are imposed on JSC human spaceflight equipment through JPD 8080.2. Designers shall comply with all design standards applicable to their design effort.

  15. Two-stage estimation in copula models used in family studies

    DEFF Research Database (Denmark)

    Andersen, Elisabeth Anne Wreford

    2005-01-01

    In this paper register based family studies provide the motivation for studying a two-stage estimation procedure in copula models for multivariate failure time data. The asymptotic properties of the estimators in both parametric and semi-parametric models are derived, generalising the approach by...

  16. Two-stage laparoscopic resection of colon cancer and metastatic liver tumour

    Directory of Open Access Journals (Sweden)

    Yukio Iwashita

    2012-01-01

    Full Text Available We report herein the case of 70-year-old woman in whom colon cancer and a synchronous metastatic liver tumour were successfully resected laparoscopically. The tumours were treated in two stages. Both post-operative courses were uneventful, and there has been no recurrence during the 8 months since the second procedure.

  17. Two-stage laparoscopic resection of colon cancer and metastatic liver tumour

    Directory of Open Access Journals (Sweden)

    Iwashita Yukio

    2005-01-01

    Full Text Available We report herein the case of 70-year-old woman in whom colon cancer and a synchronous metastatic liver tumour were successfully resected laparoscopically. The tumours were treated in two stages. Both postoperative courses were uneventful, and there has been no recurrence during the 8 months since the second procedure.

  18. Proven procedures guide cavity VCO design

    Science.gov (United States)

    Lefrak, F.

    1981-05-01

    The design of a high performance voltage-tuned cavity oscillator is discussed. The circuit is to be modeled with an equivalent inductance and capacitance. Close attention is to be given to the influence of cavity loading. Center frequency and impedance are computed on the basis of the model's L and C values. The last step is particularly important, since the size of a cavity-based oscillator, such as the Gunn/varactor version is directly related to operating frequency. Attention is given to the parallel L-C circuit representing the cavity, parameter relations concerning the height, higher-order TE modes, and effects of post inductance. The basic oscillator consists of a hollow cavity with metal walls, and diodes mounted on posts.

  19. Treatment of cadmium dust with two-stage leaching process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The treatment of cadmium dust with a two-stage leaching process was investigated to replace the existing sulphation roast-leaching processes. The process parameters in the first stage leaching were basically similar to the neutralleaching in zinc hydrometallurgy. The effects of process parameters in the second stage leaching on the extraction of zincand cadmium were mainly studied. The experimental results indicated that zinc and cadmium could be efficiently recoveredfrom the cadmium dust by two-stage leaching process. The extraction percentages of zinc and cadmium in two stage leach-ing reached 95% and 88% respectively under the optimum conditions. The total extraction percentage of Zn and Cdreached 94%.

  20. Acceptance and Divergence from Engineering Design Procedures Implicating Knowledge Flow

    DEFF Research Database (Denmark)

    Jensen, Ole Kjeldal; Ahmed, Saeema

    2009-01-01

    When developing procedures such as tools, methods and frameworks to support the development of new products, one of the challenges is ensuring their successful implementation. This paper describes a study of the development and use of such design-procedures with primary focus on the new product d...

  1. Factors affecting the design of instrument flight procedures

    Directory of Open Access Journals (Sweden)

    Ivan FERENCZ

    2008-01-01

    Full Text Available The article highlights factors, which might affect the design of instrument flight procedures. Ishikawa diagram is used to distribute individual factors into classes, as are People, Methods, Regulations, Tools, Data and Environment.

  2. Factors affecting the design of instrument flight procedures

    OpenAIRE

    Ivan FERENCZ; František JÚN; Dušan KEVICKÝ

    2008-01-01

    The article highlights factors, which might affect the design of instrument flight procedures. Ishikawa diagram is used to distribute individual factors into classes, as are People, Methods, Regulations, Tools, Data and Environment.

  3. Two-staged management for all types of congenital pouch colon

    Directory of Open Access Journals (Sweden)

    Rajendra K Ghritlaharey

    2013-01-01

    Full Text Available Background: The aim of this study was to review our experience with two-staged management for all types of congenital pouch colon (CPC. Patients and Methods: This retrospective study included CPC cases that were managed with two-staged procedures in the Department of Paediatric Surgery, over a period of 12 years from 1 January 2000 to 31 December 2011. Results: CPC comprised of 13.71% (97 of 707 of all anorectal malformations (ARM and 28.19% (97 of 344 of high ARM. Eleven CPC cases (all males were managed with two-staged procedures. Distribution of cases (Narsimha Rao et al.′s classification into types I, II, III, and IV were 1, 2, 6, and 2, respectively. Initial operative procedures performed were window colostomy (n = 6, colostomy proximal to pouch (n = 4, and ligation of colovesical fistula and end colostomy (n = 1. As definitive procedures, pouch excision with abdomino-perineal pull through (APPT of colon in eight, and pouch excision with APPT of ileum in three were performed. The mean age at the time of definitive procedures was 15.6 months (ranges from 3 to 53 months and the mean weight was 7.5 kg (ranges from 4 to 11 kg. Good fecal continence was observed in six and fair in two cases in follow-up periods, while three of our cases lost to follow up. There was no mortality following definitive procedures amongst above 11 cases. Conclusions: Two-staged procedures for all types of CPC can also be performed safely with good results. The most important fact that the definitive procedure is being done without protective stoma and therefore, it avoids stoma closure, stoma-related complications, related cost of stoma closure and hospital stay.

  4. Effect of Silica Fume on two-stage Concrete Strength

    Science.gov (United States)

    Abdelgader, H. S.; El-Baden, A. S.

    2015-11-01

    Two-stage concrete (TSC) is an innovative concrete that does not require vibration for placing and compaction. TSC is a simple concept; it is made using the same basic constituents as traditional concrete: cement, coarse aggregate, sand and water as well as mineral and chemical admixtures. As its name suggests, it is produced through a two-stage process. Firstly washed coarse aggregate is placed into the formwork in-situ. Later a specifically designed self compacting grout is introduced into the form from the lowest point under gravity pressure to fill the voids, cementing the aggregate into a monolith. The hardened concrete is dense, homogeneous and has in general improved engineering properties and durability. This paper presents the results from a research work attempt to study the effect of silica fume (SF) and superplasticizers admixtures (SP) on compressive and tensile strength of TSC using various combinations of water to cement ratio (w/c) and cement to sand ratio (c/s). Thirty six concrete mixes with different grout constituents were tested. From each mix twenty four standard cylinder samples of size (150mm×300mm) of concrete containing crushed aggregate were produced. The tested samples were made from combinations of w/c equal to: 0.45, 0.55 and 0.85, and three c/s of values: 0.5, 1 and 1.5. Silica fume was added at a dosage of 6% of weight of cement, while superplasticizer was added at a dosage of 2% of cement weight. Results indicated that both tensile and compressive strength of TSC can be statistically derived as a function of w/c and c/s with good correlation coefficients. The basic principle of traditional concrete, which says that an increase in water/cement ratio will lead to a reduction in compressive strength, was shown to hold true for TSC specimens tested. Using a combination of both silica fume and superplasticisers caused a significant increase in strength relative to control mixes.

  5. Basic Design Procedures for E-learning Courses

    NARCIS (Netherlands)

    Sloep, Peter; Hummel, Hans; Manderveld, Jocelyn

    2005-01-01

    Sloep, P., Hummel, H. & Manderveld, J. (2005). Basic Design Procedures for E-learning Courses. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 139-160). Berlin-Heidelberg: Springer Verlag.

  6. A procedure for design of hydrogen networks with multiple contaminants☆

    Institute of Scientific and Technical Information of China (English)

    Xuefei Wang; Zhe Wang; Huipeng Zhao; Zhiyong Liu

    2015-01-01

    It is necessary to reduce hydrogen consumption to meet increasingly strict environmental and product-quality regulations for refinery plants. In this paper, the concentration potential concepts proposed for design of water-using networks are extended to synthesis of hydrogen networks with multiple contaminants. In the de-sign procedure, the precedence of processes is determined by the values of concentration potential of demands. The usage of complementary source pair(s) to reduce utility consumption is investigated. Three case studies are presented to il ustrate the effectiveness of the method. It is shown that the design procedure has clear engineer-ing meaning.

  7. Two-stage unilateral versus one-stage bilateral single-port sympathectomy for palmar and axillary hyperhidrosis†

    Science.gov (United States)

    Ibrahim, Mohsen; Menna, Cecilia; Andreetti, Claudio; Ciccone, Anna Maria; D'Andrilli, Antonio; Maurizi, Giulio; Poggi, Camilla; Vanni, Camilla; Venuta, Federico; Rendina, Erino Angelo

    2013-01-01

    OBJECTIVES Video-assisted thoracoscopic sympathectomy is currently the best treatment for palmar and axillary hyperhidrosis. It can be performed through either one or two stages of surgery. This study aimed to evaluate the operative and postoperative results of two-stage unilateral vs one-stage bilateral thoracoscopic sympathectomy. METHODS From November 1995 to February 2011, 270 patients with severe palmar and/or axillary hyperhidrosis were recruited for this study. One hundred and thirty patients received one-stage bilateral, single-port video-assisted thoracoscopic sympathectomy (one-stage group) and 140, two-stage unilateral, single-port video-assisted thoracoscopic sympathectomy, with a mean time interval of 4 months between the procedures (two-stage group). RESULTS The mean postoperative follow-up period was 12.5 (range: 1–24 months). After surgery, hands and axillae of all patients were dry and warm. Sixteen (12%) patients of the one-stage group and 15 (11%) of the two-stage group suffered from mild/moderate pain (P = 0.8482). The mean operative time was 38 ± 5 min in the one-stage group and 39 ± 8 min in the two-stage group (P = 0.199). Pneumothorax occurred in 8 (6%) patients of the one-stage group and in 11 (8%) of the two-stage group. Compensatory sweating occurred in 25 (19%) patients of the one-stage group and in 6 (4%) of the two-stage group (P = 0.0001). No patients developed Horner's syndrome. CONCLUSIONS Both two-stage unilateral and one-stage bilateral single-port video-assisted thoracoscopic sympathectomies are effective, safe and minimally invasive procedures. Two-stage unilateral sympathectomy can be performed with a lower occurrence of compensatory sweating, improving permanently the quality of life in patients with palmar and axillary hyperhidrosis. PMID:23442937

  8. Two-stage unilateral versus one-stage bilateral single-port sympathectomy for palmar and axillary hyperhidrosis.

    Science.gov (United States)

    Ibrahim, Mohsen; Menna, Cecilia; Andreetti, Claudio; Ciccone, Anna Maria; D'Andrilli, Antonio; Maurizi, Giulio; Poggi, Camilla; Vanni, Camilla; Venuta, Federico; Rendina, Erino Angelo

    2013-06-01

    Video-assisted thoracoscopic sympathectomy is currently the best treatment for palmar and axillary hyperhidrosis. It can be performed through either one or two stages of surgery. This study aimed to evaluate the operative and postoperative results of two-stage unilateral vs one-stage bilateral thoracoscopic sympathectomy. From November 1995 to February 2011, 270 patients with severe palmar and/or axillary hyperhidrosis were recruited for this study. One hundred and thirty patients received one-stage bilateral, single-port video-assisted thoracoscopic sympathectomy (one-stage group) and 140, two-stage unilateral, single-port video-assisted thoracoscopic sympathectomy, with a mean time interval of 4 months between the procedures (two-stage group). The mean postoperative follow-up period was 12.5 (range: 1-24 months). After surgery, hands and axillae of all patients were dry and warm. Sixteen (12%) patients of the one-stage group and 15 (11%) of the two-stage group suffered from mild/moderate pain (P = 0.8482). The mean operative time was 38 ± 5 min in the one-stage group and 39 ± 8 min in the two-stage group (P = 0.199). Pneumothorax occurred in 8 (6%) patients of the one-stage group and in 11 (8%) of the two-stage group. Compensatory sweating occurred in 25 (19%) patients of the one-stage group and in 6 (4%) of the two-stage group (P = 0.0001). No patients developed Horner's syndrome. Both two-stage unilateral and one-stage bilateral single-port video-assisted thoracoscopic sympathectomies are effective, safe and minimally invasive procedures. Two-stage unilateral sympathectomy can be performed with a lower occurrence of compensatory sweating, improving permanently the quality of life in patients with palmar and axillary hyperhidrosis.

  9. PERFORMANCE STUDY OF A TWO STAGE SOLAR ADSORPTION REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    BAIJU. V

    2011-07-01

    Full Text Available The present study deals with the performance of a two stage solar adsorption refrigeration system with activated carbon-methanol pair investigated experimentally. Such a system was fabricated and tested under the conditions of National Institute of Technology Calicut, Kerala, India. The system consists of a parabolic solar concentrator,two water tanks, two adsorbent beds, condenser, expansion device, evaporator and accumulator. In this particular system the second water tank is act as a sensible heat storage device so that the system can be used during night time also. The system has been designed for heating 50 litres of water from 25oC to 90oC as well ascooling 10 litres of water from 30oC to 10oC within one hour. The performance parameters such as specific cooling power (SCP, coefficient of performance, solar COP and exergetic efficiency are studied. The dependency between the exergetic efficiency and cycle COP with the driving heat source temperature is also studied. The optimum heat source temperature for this system is determined as 72.4oC. The results show that the system has better performance during night time as compared to the day time. The system has a mean cycle COP of 0.196 during day time and 0.335 for night time. The mean SCP values during day time and night time are 47.83 and 68.2, respectively. The experimental results also demonstrate that the refrigerator has cooling capacity of 47 to 78 W during day time and 57.6 W to 104.4W during night time.

  10. STARS A Two Stage High Gain Harmonic Generation FEL Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    M. Abo-Bakr; W. Anders; J. Bahrdt; P. Budz; K.B. Buerkmann-Gehrlein; O. Dressler; H.A. Duerr; V. Duerr; W. Eberhardt; S. Eisebitt; J. Feikes; R. Follath; A. Gaupp; R. Goergen; K. Goldammer; S.C. Hessler; K. Holldack; E. Jaeschke; Thorsten Kamps; S. Klauke; J. Knobloch; O. Kugeler; B.C. Kuske; P. Kuske; A. Meseck; R. Mitzner; R. Mueller; M. Neeb; A. Neumann; K. Ott; D. Pfluckhahn; T. Quast; M. Scheer; Th. Schroeter; M. Schuster; F. Senf; G. Wuestefeld; D. Kramer; Frank Marhauser

    2007-08-01

    BESSY is proposing a demonstration facility, called STARS, for a two-stage high-gain harmonic generation free electron laser (HGHG FEL). STARS is planned for lasing in the wavelength range 40 to 70 nm, requiring a beam energy of 325 MeV. The facility consists of a normal conducting gun, three superconducting TESLA-type acceleration modules modified for CW operation, a single stage bunch compressor and finally a two-stage HGHG cascaded FEL. This paper describes the faciliy layout and the rationale behind the operation parameters.

  11. Design Guidance for Computer-Based Procedures for Field Workers

    Energy Technology Data Exchange (ETDEWEB)

    Oxstrand, Johanna [Idaho National Lab. (INL), Idaho Falls, ID (United States); Le Blanc, Katya [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bly, Aaron [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    Nearly all activities that involve human interaction with nuclear power plant systems are guided by procedures, instructions, or checklists. Paper-based procedures (PBPs) currently used by most utilities have a demonstrated history of ensuring safety; however, improving procedure use could yield significant savings in increased efficiency, as well as improved safety through human performance gains. The nuclear industry is constantly trying to find ways to decrease human error rates, especially human error rates associated with procedure use. As a step toward the goal of improving field workers’ procedure use and adherence and hence improve human performance and overall system reliability, the U.S. Department of Energy Light Water Reactor Sustainability (LWRS) Program researchers, together with the nuclear industry, have been investigating the possibility and feasibility of replacing current paper-based procedures with computer-based procedures (CBPs). PBPs have ensured safe operation of plants for decades, but limitations in paper-based systems do not allow them to reach the full potential for procedures to prevent human errors. The environment in a nuclear power plant is constantly changing, depending on current plant status and operating mode. PBPs, which are static by nature, are being applied to a constantly changing context. This constraint often results in PBPs that are written in a manner that is intended to cover many potential operating scenarios. Hence, the procedure layout forces the operator to search through a large amount of irrelevant information to locate the pieces of information relevant for the task and situation at hand, which has potential consequences of taking up valuable time when operators must be responding to the situation, and potentially leading operators down an incorrect response path. Other challenges related to use of PBPs are management of multiple procedures, place-keeping, finding the correct procedure for a task, and relying

  12. Development of a linear compressor for two-stage pulse tube cryocoolers

    Institute of Scientific and Technical Information of China (English)

    Peng-da YAN; Wei-li GAO; Guo-bang CHEN

    2009-01-01

    A valveless linear compressor was built up to drive a self-made two-stage pulse tube cryocooler. With a designed maximum swept volume of 60 cm~3, the compressor can provide the cryocooler with a pressure volume (PV) power of 400 W.Preliminary measurements of the compressor indicated that both an efficiency of 35%~55% and a pressure ratio of 1.3~1.4 could be obtained. The two-stage pulse tube cryocooler driven by this compressor achieved the lowest temperature of 14.2 K.

  13. Development of a heavy-duty diesel engine with two-stage turbocharging

    NARCIS (Netherlands)

    Sturm, L.; Kruithof, J.

    2001-01-01

    A mean value model was developed by using Matrixx/ Systembuild simulation tool for designing real-time control algorithms for the two-stage engine. All desired characteristics are achieved, apart from lower A/F ratio at lower engine speeds and Turbocharger matches calculations. The CANbus is used to

  14. Two-stage, dilute sulfuric acid hydrolysis of wood : an investigation of fundamentals

    Science.gov (United States)

    John F. Harris; Andrew J. Baker; Anthony H. Conner; Thomas W. Jeffries; James L. Minor; Roger C. Pettersen; Ralph W. Scott; Edward L Springer; Theodore H. Wegner; John I. Zerbe

    1985-01-01

    This paper presents a fundamental analysis of the processing steps in the production of methanol from southern red oak (Quercus falcata Michx.) by two-stage dilute sulfuric acid hydrolysis. Data for hemicellulose and cellulose hydrolysis are correlated using models. This information is used to develop and evaluate a process design.

  15. A Two-Stage Exercise on the Binomial Distribution Using Minitab.

    Science.gov (United States)

    Shibli, M. Abdullah

    1990-01-01

    Describes a two-stage experiment that was designed to explain binomial distribution to undergraduate statistics students. A manual coin flipping exercise is explained as the first stage; a computerized simulation using MINITAB software is presented as stage two; and output from the MINITAB exercises is included. (two references) (LRW)

  16. Analysis of performance and optimum configuration of two-stage semiconductor thermoelectric module

    Institute of Scientific and Technical Information of China (English)

    Li Kai-Zhen; Liang Rui-Sheng; Wei Zheng-Jun

    2008-01-01

    In this paper, the theoretical analysis and simulating calculation were conducted for a basic two-stage semiconductor thermoelectric module, which contains one thermocouple in the second stage and several thermocouples in the first stage. The study focused on the configuration of the two-stage semiconductor thermoelectric cooler, especially investigating the influences of some parameters, such as the current I1 of the first stage, the area A1 of every thermocouple and the number n of thermocouples in the first stage, on the cooling performance of the module. The obtained results of analysis indicate that changing the current I1 of the first stage, the area A1 of thcrmocouples and the number n of thermocouples in the first stage can improve the cooling performance of the module. These results can be used to optimize the configuration of the two-stage semiconductor thermoelectric module and provide guides for the design and application of thermoelectric cooler.

  17. Two-Stage Fuzzy Portfolio Selection Problem with Transaction Costs

    Directory of Open Access Journals (Sweden)

    Yanju Chen

    2015-01-01

    Full Text Available This paper studies a two-period portfolio selection problem. The problem is formulated as a two-stage fuzzy portfolio selection model with transaction costs, in which the future returns of risky security are characterized by possibility distributions. The objective of the proposed model is to achieve the maximum utility in terms of the expected value and variance of the final wealth. Given the first-stage decision vector and a realization of fuzzy return, the optimal value expression of the second-stage programming problem is derived. As a result, the proposed two-stage model is equivalent to a single-stage model, and the analytical optimal solution of the two-stage model is obtained, which helps us to discuss the properties of the optimal solution. Finally, some numerical experiments are performed to demonstrate the new modeling idea and the effectiveness. The computational results provided by the proposed model show that the more risk-averse investor will invest more wealth in the risk-free security. They also show that the optimal invested amount in risky security increases as the risk-free return decreases and the optimal utility increases as the risk-free return increases, whereas the optimal utility increases as the transaction costs decrease. In most instances the utilities provided by the proposed two-stage model are larger than those provided by the single-stage model.

  18. Efficient Two-Stage Group Testing Algorithms for DNA Screening

    CERN Document Server

    Huber, Michael

    2011-01-01

    Group testing algorithms are very useful tools for DNA library screening. Building on recent work by Levenshtein (2003) and Tonchev (2008), we construct in this paper new infinite classes of combinatorial structures, the existence of which are essential for attaining the minimum number of individual tests at the second stage of a two-stage disjunctive testing algorithm.

  19. A two-stage rank test using density estimation

    NARCIS (Netherlands)

    Albers, Willem/Wim

    1995-01-01

    For the one-sample problem, a two-stage rank test is derived which realizes a required power against a given local alternative, for all sufficiently smooth underlying distributions. This is achieved using asymptotic expansions resulting in a precision of orderm −1, wherem is the size of the first

  20. The construction of customized two-stage tests

    NARCIS (Netherlands)

    Adema, Jos J.

    1990-01-01

    In this paper mixed integer linear programming models for customizing two-stage tests are given. Model constraints are imposed with respect to test composition, administration time, inter-item dependencies, and other practical considerations. It is not difficult to modify the models to make them use

  1. A two-stage subsurface vertical flow constructed wetland for high-rate nitrogen removal.

    Science.gov (United States)

    Langergraber, Guenter; Leroch, Klaus; Pressl, Alexander; Rohrhofer, Roland; Haberl, Raimund

    2008-01-01

    By using a two-stage constructed wetland (CW) system operated with an organic load of 40 gCOD.m(-2).d(-1) (2 m2 per person equivalent) average nitrogen removal efficiencies of about 50% and average nitrogen elimination rates of 980 g N.m(-2).yr(-1) could be achieved. Two vertical flow beds with intermittent loading have been operated in series. The first stage uses sand with a grain size of 2-3.2 mm for the main layer and has a drainage layer that is impounded; the second stage sand with a grain size of 0.06-4 mm and a drainage layer with free drainage. The high nitrogen removal can be achieved without recirculation thus it is possible to operate the two-stage CW system without energy input. The paper shows performance data for the two-stage CW system regarding removal of organic matter and nitrogen for the two year operating period of the system. Additionally, its efficiency is compared with the efficiency of a single-stage vertical flow CW system designed and operated according to the Austrian design standards with 4 m2 per person equivalent. The comparison shows that a higher effluent quality could be reached with the two-stage system although the two-stage CW system is operated with the double organic load or half the specific surface area requirement, respectively. Another advantage is that the specific investment costs of the two-stage CW system amount to 1,200 EUR per person (without mechanical pre-treatment) and are only about 60% of the specific investment costs of the singe-stage CW system. IWA Publishing 2008.

  2. A Rapid Aerodynamic Design Procedure Based on Artificial Neural Networks

    Science.gov (United States)

    Rai, Man Mohan

    2001-01-01

    An aerodynamic design procedure that uses neural networks to model the functional behavior of the objective function in design space has been developed. This method incorporates several improvements to an earlier method that employed a strategy called parameter-based partitioning of the design space in order to reduce the computational costs associated with design optimization. As with the earlier method, the current method uses a sequence of response surfaces to traverse the design space in search of the optimal solution. The new method yields significant reductions in computational costs by using composite response surfaces with better generalization capabilities and by exploiting synergies between the optimization method and the simulation codes used to generate the training data. These reductions in design optimization costs are demonstrated for a turbine airfoil design study where a generic shape is evolved into an optimal airfoil.

  3. 17 CFR 38.3 - Procedures for designation.

    Science.gov (United States)

    2010-04-01

    ....3 Section 38.3 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION DESIGNATED... of this chapter) and any technical manuals, other guides or instructions for users of, or... description of the trading system, algorithm, security and access limitation procedures with a timeline for an...

  4. ON TIME-OPTIMAL PROCEDURE FOR ANALOG SYSTEM DESIGN

    Directory of Open Access Journals (Sweden)

    A. Zemliak

    2004-04-01

    Full Text Available The process of any analog system design has been formulated on the basis of the control theory application. Thisapproach produces many different design strategies inside the same optimization procedure and allowsdetermining the problem of the optimal design strategy existence from the computer time point of view. Differentkinds of system design strategies have been evaluated from the operations number. The general methodology forthe analog system design was formulated by means of the optimum control theory. The main equations for thisdesign methodology were elaborated. These equations include the special control functions that are introducedartificially. This approach generalizes the design process and generates an infinite number of the different designstrategies. The problem of the optimum design algorithm construction is defined as the minimum-time problem ofthe control theory. Numerical results of some electronic circuit design demonstrate the efficiency and perspectiveof the proposed methodology. These examples show that the computer time gain of the optimal design strategywith respect to the traditional design strategy increases when the size and complexity of the system increase. Anadditional acceleration effect of the design process has been discovered by the analysis of various design strategieswith the different initial points. This effect is displayed for all analyzed circuits and it reduces additionally the totalcomputer time for the system design.

  5. Two-stage data envelopment analysis technique for evaluating internal supply chain efficiency

    Directory of Open Access Journals (Sweden)

    Nisakorn Somsuk

    2014-12-01

    Full Text Available A two-stage data envelopment analysis (DEA which uses mathematical linear programming techniques is applied to evaluate the efficiency of a system composed of two relational sub-processes, by which the outputs from the first sub-process (as the intermediate outputs of the system are the inputs for the second sub-process. The relative efficiencies of the system and its sub-processes can be measured by applying the two-stage DEA. According to the literature review on the supply chain management, this technique can be used as a tool for evaluating the efficiency of the supply chain composed of two relational sub-processes. The technique can help to determine the inefficient sub-processes. Once the inefficient sub-process was improved its efficiency, it would result in better aggregate efficiency of the supply chain. This paper aims to present a procedure for evaluating the efficiency of the supply chain by using the two-stage DEA, under the assumption of constant returns to scale, with an example of internal supply chain efficiency measurement of insurance companies by applying the two-stage DEA for illustration. Moreover, in this paper the authors also present some observations on the application of this technique.

  6. Extraoral implants for orbit rehabilitation: a comparison between one-stage and two-stage surgeries.

    Science.gov (United States)

    de Mello, M C L M P; Guedes, R; de Oliveira, J A P; Pecorari, V A; Abrahão, M; Dib, L L

    2014-03-01

    The aim of the study was to compare the osseointegration success rate and time for delivery of the prosthesis among cases treated by two-stage or one-stage surgery for orbit rehabilitation between 2003 and 2011. Forty-five patients were included, 31 males and 14 females; 22 patients had two-stage surgery and 23 patients had one-stage surgery. A total 138 implants were installed, 42 (30.4%) on previously irradiated bone. The implant survival rate was 96.4%, with a success rate of 99.0% among non-irradiated patients and 90.5% among irradiated patients. Two-stage patients received 74 implants with a survival rate of 94.6% (four implants lost); one-stage surgery patients received 64 implants with a survival rate of 98.4% (one implant lost). The median time interval between implant fixation and delivery of the prosthesis for the two-stage group was 9.6 months and for the one-stage group was 4.0 months (P < 0.001). The one-stage technique proved to be reliable and was associated with few risks and complications; the rate of successful osseointegration was similar to those reported in the literature. The one-stage technique should be considered a viable procedure that shortens the time to final rehabilitation and facilitates appropriate patient follow-up treatment.

  7. PGSFR Core Thermal Design Procedure to Evaluate the Safety Margin

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sun Rock; Kim, Sang-Ji [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The Korea Atomic Energy Research Institute (KAERI) has performed a SFR design with the final goal of constructing a prototype plant by 2028. The main objective of the SFR prototype plant is to verify the TRU metal fuel performance, reactor operation, and transmutation ability of high-level wastes. The core thermal design is to ensure the safe fuel performance during the whole plant operation. Compared to the critical heat flux in typical light water reactors, nuclear fuel damage in SFR subassemblies arises from a creep induced failure. The creep limit is evaluated based on the maximum cladding temperature, power, neutron flux, and uncertainties in the design parameters, as shown in Fig. 1. In this work, the core thermal design procedures are compared to verify the present PGSFR methodology based on the nuclear plant design criteria/guidelines and previous SFR thermal design methods. The PGSFR core thermal design procedure is verified based on the nuclear plant design criteria/guidelines and previous methods in LWRs and SFRs. The present method aims to directly evaluate the fuel cladding failure and to assure more safety margin. The 2 uncertainty is similar to 95% one-side tolerance limit of 1.96 in LWRs. The HCFs, ITDP, and MCM reveal similar uncertainty propagation for cladding midwall temperature for typical SFR conditions. The present HCFs are mainly employed from the CRBR except the fuel-related uncertainty such as an incorrect fuel distribution. Preliminary PGSFR specific HCFs will be developed by the end of 2015.

  8. Procedural design of exterior lighting for buildings with complex constraints

    KAUST Repository

    Schwarz, Michael

    2014-09-23

    We present a system for the lighting design of procedurally modeled buildings. The design is procedurally specified as part of the ordinary modeling workflow by defining goals for the illumination that should be attained and locations where luminaires may be installed to realize these goals. Additionally, constraints can be modeled that make the arrangement of the installed luminaires respect certain aesthetic and structural considerations. From this specification, the system automatically generates a lighting solution for any concrete model instance. The underlying, intricate joint optimization and constraint satisfaction problem is approached with a stochastic scheme that operates directly in the complex subspace where all constraints are observed. To navigate this subspace efficaciously, the actual lighting situation is taken into account. We demonstrate our system on multiple examples spanning a variety of architectural structures and lighting designs. Copyright held by the Owner/Author.

  9. Health care planning and education via gaming-simulation: a two-stage experiment.

    Science.gov (United States)

    Gagnon, J H; Greenblat, C S

    1977-01-01

    A two-stage process of gaming-simulation design was conducted: the first stage of design concerned national planning for hemophilia care; the second stage of design was for gaming-simulation concerning the problems of hemophilia patients and health care providers. The planning design was intended to be adaptable to large-scale planning for a variety of health care problems. The educational game was designed using data developed in designing the planning game. A broad range of policy-makers participated in the planning game.

  10. An intracooling system for a novel two-stage sliding-vane air compressor

    Science.gov (United States)

    Murgia, Stefano; Valenti, Gianluca; Costanzo, Ida; Colletta, Daniele; Contaldi, Giulio

    2017-08-01

    Lube-oil injection is used in positive-displacement compressors and, among them, in sliding-vane machines to guarantee the correct lubrication of the moving parts and as sealing to prevent air leakage. Furthermore, lube-oil injection allows to exploit lubricant also as thermal ballast with a great thermal capacity to minimize the temperature increase during the compression. This study presents the design of a two-stage sliding-vane rotary compressor in which the air cooling is operated by high-pressure cold oil injection into a connection duct between the two stages. The heat exchange between the atomized oil jet and the air results in a decrease of the air temperature before the second stage, improving the overall system efficiency. This cooling system is named here intracooling, as opposed to intercooling. The oil injection is realized via pressure-swirl nozzles, both within the compressors and inside the intracooling duct. The design of the two-stage sliding-vane compressor is accomplished by way of a lumped parameter model. The model predicts an input power reduction as large as 10% for intercooled and intracooled two-stage compressors, the latter being slightly better, with respect to a conventional single-stage compressor for compressed air applications. An experimental campaign is conducted on a first prototype that comprises the low-pressure compressor and the intracooling duct, indicating that a significant temperature reduction is achieved in the duct.

  11. Square Kilometre Array station configuration using two-stage beamforming

    CERN Document Server

    Jiwani, Aziz; Razavi-Ghods, Nima; Hall, Peter J; Padhi, Shantanu; de Vaate, Jan Geralt bij

    2012-01-01

    The lowest frequency band (70 - 450 MHz) of the Square Kilometre Array will consist of sparse aperture arrays grouped into geographically-localised patches, or stations. Signals from thousands of antennas in each station will be beamformed to produce station beams which form the inputs for the central correlator. Two-stage beamforming within stations can reduce SKA-low signal processing load and costs, but has not been previously explored for the irregular station layouts now favoured in radio astronomy arrays. This paper illustrates the effects of two-stage beamforming on sidelobes and effective area, for two representative station layouts (regular and irregular gridded tile on an irregular station). The performance is compared with a single-stage, irregular station. The inner sidelobe levels do not change significantly between layouts, but the more distant sidelobes are affected by the tile layouts; regular tile creates diffuse, but regular, grating lobes. With very sparse arrays, the station effective area...

  12. Two stage sorption type cryogenic refrigerator including heat regeneration system

    Science.gov (United States)

    Jones, Jack A.; Wen, Liang-Chi; Bard, Steven

    1989-01-01

    A lower stage chemisorption refrigeration system physically and functionally coupled to an upper stage physical adsorption refrigeration system is disclosed. Waste heat generated by the lower stage cycle is regenerated to fuel the upper stage cycle thereby greatly improving the energy efficiency of a two-stage sorption refrigerator. The two stages are joined by disposing a first pressurization chamber providing a high pressure flow of a first refrigerant for the lower stage refrigeration cycle within a second pressurization chamber providing a high pressure flow of a second refrigerant for the upper stage refrigeration cycle. The first pressurization chamber is separated from the second pressurization chamber by a gas-gap thermal switch which at times is filled with a thermoconductive fluid to allow conduction of heat from the first pressurization chamber to the second pressurization chamber.

  13. Recursive algorithm for the two-stage EFOP estimation method

    Institute of Scientific and Technical Information of China (English)

    LUO GuiMing; HUANG Jian

    2008-01-01

    A recursive algorithm for the two-stage empirical frequency-domain optimal param-eter (EFOP) estimation method Was proposed. The EFOP method was a novel sys-tem identificallon method for Black-box models that combines time-domain esti-mation and frequency-domain estimation. It has improved anti-disturbance perfor-mance, and could precisely identify models with fewer sample numbers. The two-stage EFOP method based on the boot-strap technique was generally suitable for Black-box models, but it was an iterative method and takes too much computation work so that it did not work well online. A recursive algorithm was proposed for dis-turbed stochastic systems. Some simulation examples are included to demonstrate the validity of the new method.

  14. Two-stage approach to full Chinese parsing

    Institute of Scientific and Technical Information of China (English)

    Cao Hailong; Zhao Tiejun; Yang Muyun; Li Sheng

    2005-01-01

    Natural language parsing is a task of great importance and extreme difficulty. In this paper, we present a full Chinese parsing system based on a two-stage approach. Rather than identifying all phrases by a uniform model, we utilize a divide and conquer strategy. We propose an effective and fast method based on Markov model to identify the base phrases. Then we make the first attempt to extend one of the best English parsing models i.e. the head-driven model to recognize Chinese complex phrases. Our two-stage approach is superior to the uniform approach in two aspects. First, it creates synergy between the Markov model and the head-driven model. Second, it reduces the complexity of full Chinese parsing and makes the parsing system space and time efficient. We evaluate our approach in PARSEVAL measures on the open test set, the parsing system performances at 87.53% precision, 87.95% recall.

  15. Income and Poverty across SMSAs: A Two-Stage Analysis

    OpenAIRE

    1993-01-01

    Two popular explanations of urban poverty are the "welfare-disincentive" and "urban-deindustrialization" theories. Using cross-sectional Census data, we develop a two-stage model to predict an SMSAs median family income and poverty rate. The model allows the city's welfare level and industrial structure to affect its median family income and poverty rate directly. It also allows welfare and industrial structure to affect income and poverty indirectly, through their effects on family structure...

  16. A Two-stage Polynomial Method for Spectrum Emissivity Modeling

    OpenAIRE

    Qiu, Qirong; Liu, Shi; Teng, Jing; Yan, Yong

    2015-01-01

    Spectral emissivity is a key in the temperature measurement by radiation methods, but not easy to determine in a combustion environment, due to the interrelated influence of temperature and wave length of the radiation. In multi-wavelength radiation thermometry, knowing the spectral emissivity of the material is a prerequisite. However in many circumstances such a property is a complex function of temperature and wavelength and reliable models are yet to be sought. In this study, a two stages...

  17. An Extensive QFD and Evaluation Procedure for Innovative Design

    Directory of Open Access Journals (Sweden)

    Chang-Tzuoh Wu

    2013-01-01

    Full Text Available In this paper, a systematic innovation procedure has been developed based on quality function deployment and extension method. Besides, the evaluation method for design decision making has also been discussed and developed. The major procedure of QFD is to identify the customers’ needs for the product and then convert into appropriate technical measures to fulfill the needs based on the company’s competitive priorities. The priorities of product characteristics can be obtained by translating important technical measures. According to their characteristics, the prior engineering parameters will be identified and selected as the key requirements to redesign. This paper will focus on the integration of QFD and extension method. With the help of “matter element theory and extension method,” customer requirements (CRs can be transferred into product design attributes more comprehensively and deeply. According to the idea of loss function of Taguchi quality design method, the criteria for design decision making have also been developed in this paper. An innovative design case, bicycle, successfully demonstrates that the proposed design process is feasible and efficient.

  18. The Bracka two-stage repair for severe proximal hypospadias: A single center experience

    Directory of Open Access Journals (Sweden)

    Rakesh S Joshi

    2015-01-01

    Full Text Available Background: Surgical correction of severe proximal hypospadias represents a significant surgical challenge and single-stage corrections are often associated with complications and reoperations. Bracka two-stage repair is an attractive alternative surgical procedure with superior, reliable, and reproducible results. Purpose: To study the feasibility and applicability of Bracka two-stage repair for the severe proximal hypospadias and to analyze the outcomes and complications of this surgical technique. Materials and Methods: This prospective study was conducted from January 2011 to December 2013. Bracka two-stage repair was performed using inner preputial skin as a free graft in subjects with proximal hypospadias in whom severe degree of chordee and/or poor urethral plate was present. Only primary cases were included in this study. All subjects received three doses of intra-muscular testosterone 3 weeks apart before first stage. Second stage was performed 6 months after the first stage. Follow-up ranged from 6 months to 24 months. Results: A total of 43 patients operated for Bracka repair, out of which 30 patients completed two-stage repair. Mean age of the patients was 4 years and 8 months. We achieved 100% graft uptake and no revision was required. Three patients developed fistula, while two had metal stenosis. Glans dehiscence, urethral stricture and the residual chordee were not found during follow-up and satisfactory cosmetic results with good urinary stream were achieved in all cases. Conclusion: The Bracka two-stage repair is a safe and reliable approach in select patients in whom it is impractical to maintain the axial integrity of the urethral plate, and, therefore, a full circumference urethral reconstruction become necessary. This gives good results both in terms of restoration of normal function with minimal complication.

  19. On the design of flight-deck procedures

    Science.gov (United States)

    Degani, Asaf; Wiener, Earl L.

    1994-01-01

    In complex human-machine systems, operations, training, and standardization depend on a elaborate set of procedures which are specified and mandated by the operational management of the organization. The intent is to provide guidance to the pilots, to ensure a logical, efficient, safe, and predictable means of carrying out the mission objectives. In this report the authors examine the issue of procedure use and design from a broad viewpoint. The authors recommend a process which we call 'The Four P's:' philosophy, policies, procedures, and practices. We believe that if an organization commits to this process, it can create a set of procedures that are more internally consistent, less confusing, better respected by the flight crews, and that will lead to greater conformity. The 'Four-P' model, and the guidelines for procedural development in appendix 1, resulted from cockpit observations, extensive interviews with airline management and pilots, interviews and discussion at one major airframe manufacturer, and an examination of accident and incident reports. Although this report is based on airline operations, we believe that the principles may be applicable to other complex, high-risk systems, such as nuclear power production, manufacturing process control, space flight, and military operations.

  20. Forty-five-degree two-stage venous cannula: advantages over standard two-stage venous cannulation.

    Science.gov (United States)

    Lawrence, D R; Desai, J B

    1997-01-01

    We present a 45-degree two-stage venous cannula that confers advantage to the surgeon using cardiopulmonary bypass. This cannula exits the mediastinum under the transverse bar of the sternal retractor, leaving the rostral end of the sternal incision free of apparatus. It allows for lifting of the heart with minimal effect on venous return and does not interfere with the radially laid out sutures of an aortic valve replacement using an interrupted suture technique.

  1. Innovative two-stage anaerobic process for effective codigestion of cheese whey and cattle manure.

    Science.gov (United States)

    Bertin, Lorenzo; Grilli, Selene; Spagni, Alessandro; Fava, Fabio

    2013-01-01

    The valorisation of agroindustrial waste through anaerobic digestion represents a significant opportunity for refuse treatment and renewable energy production. This study aimed to improve the codigestion of cheese whey (CW) and cattle manure (CM) by an innovative two-stage process, based on concentric acidogenic and methanogenic phases, designed for enhancing performance and reducing footprint. The optimum CW to CM ratio was evaluated under batch conditions. Thereafter, codigestion was implemented under continuous-flow conditions comparing one- and two-stage processes. The results demonstrated that the addition of CM in codigestion with CW greatly improved the anaerobic process. The highest methane yield was obtained co-treating the two substrates at equal ratio by using the innovative two-stage process. The proposed system reached the maximum value of 258 mL(CH4) g(gv(-1), which was more than twice the value obtained by the one-stage process and 10% higher than the value obtained by the two-stage one.

  2. Two stage treatment of dairy effluent using immobilized Chlorella pyrenoidosa.

    Science.gov (United States)

    Yadavalli, Rajasri; Heggers, Goutham Rao Venkata Naga

    2013-12-19

    Dairy effluents contains high organic load and unscrupulous discharge of these effluents into aquatic bodies is a matter of serious concern besides deteriorating their water quality. Whilst physico-chemical treatment is the common mode of treatment, immobilized microalgae can be potentially employed to treat high organic content which offer numerous benefits along with waste water treatment. A novel low cost two stage treatment was employed for the complete treatment of dairy effluent. The first stage consists of treating the diary effluent in a photobioreactor (1 L) using immobilized Chlorella pyrenoidosa while the second stage involves a two column sand bed filtration technique. Whilst NH4+-N was completely removed, a 98% removal of PO43--P was achieved within 96 h of two stage purification processes. The filtrate was tested for toxicity and no mortality was observed in the zebra fish which was used as a model at the end of 96 h bioassay. Moreover, a significant decrease in biological oxygen demand and chemical oxygen demand was achieved by this novel method. Also the biomass separated was tested as a biofertilizer to the rice seeds and a 30% increase in terms of length of root and shoot was observed after the addition of biomass to the rice plants. We conclude that the two stage treatment of dairy effluent is highly effective in removal of BOD and COD besides nutrients like nitrates and phosphates. The treatment also helps in discharging treated waste water safely into the receiving water bodies since it is non toxic for aquatic life. Further, the algal biomass separated after first stage of treatment was highly capable of increasing the growth of rice plants because of nitrogen fixation ability of the green alga and offers a great potential as a biofertilizer.

  3. Two-stage series array SQUID amplifier for space applications

    Science.gov (United States)

    Tuttle, J. G.; DiPirro, M. J.; Shirron, P. J.; Welty, R. P.; Radparvar, M.

    We present test results for a two-stage integrated SQUID amplifier which uses a series array of d.c. SQUIDS to amplify the signal from a single input SQUID. The device was developed by Welty and Martinis at NIST and recent versions have been manufactured by HYPRES, Inc. Shielding and filtering techniques were employed during the testing to minimize the external noise. Energy resolution of 300 h was demonstrated using a d.c. excitation at frequencies above 1 kHz, and better than 500 h resolution was typical down to 300 Hz.

  4. Two-Stage Aggregate Formation via Streams in Myxobacteria

    Science.gov (United States)

    Alber, Mark; Kiskowski, Maria; Jiang, Yi

    2005-03-01

    In response to adverse conditions, myxobacteria form aggregates which develop into fruiting bodies. We model myxobacteria aggregation with a lattice cell model based entirely on short range (non-chemotactic) cell-cell interactions. Local rules result in a two-stage process of aggregation mediated by transient streams. Aggregates resemble those observed in experiment and are stable against even very large perturbations. Noise in individual cell behavior increases the effects of streams and result in larger, more stable aggregates. Phys. Rev. Lett. 93: 068301 (2004).

  5. Straw Gasification in a Two-Stage Gasifier

    DEFF Research Database (Denmark)

    Bentzen, Jens Dall; Hindsgaul, Claus; Henriksen, Ulrik Birk

    2002-01-01

    Additive-prepared straw pellets were gasified in the 100 kW two-stage gasifier at The Department of Mechanical Engineering of the Technical University of Denmark (DTU). The fixed bed temperature range was 800-1000°C. In order to avoid bed sintering, as observed earlier with straw gasification...... residues were examined after the test. No agglomeration or sintering was observed in the ash residues. The tar content was measured both by solid phase amino adsorption (SPA) method and cold trapping (Petersen method). Both showed low tar contents (~42 mg/Nm3 without gas cleaning). The particle content...

  6. Conceptual Design and Procedure for an Autonomous Intramyocardial Injection Catheter.

    Science.gov (United States)

    Cheng, Weyland; Law, Peter

    2016-12-07

    This article discusses existing catheter systems and proposes a conceptual design and procedure for an autonomous cellinjection catheter for the purpose of transferring committed myogenic or undifferentiated stem cells into the infarct boundary zones of the left ventricle. Operation of existing catheters used for cell delivery is far from optimal. Commercial injection catheters available are hand-held devices operated manually by means of tip deflection and torque capabilities. Interventionists require a hefty learning curve and often encounter difficulties in catheter stabilization and infarct detection, resulting in lengthy operation times and non-precise injections. We examined current technologies and proposed a design incorporating robotic positional control, feedback signals, and an adaptable operational sequence to overcome these problems. The design provides the basis for the construction of a robotic catheter that is able to autonomously assist the physician in transferring myogenic cells to the left ventricle infarct boundary zones.

  7. Two-stage perceptual learning to break visual crowding.

    Science.gov (United States)

    Zhu, Ziyun; Fan, Zhenzhi; Fang, Fang

    2016-01-01

    When a target is presented with nearby flankers in the peripheral visual field, it becomes harder to identify, which is referred to as crowding. Crowding sets a fundamental limit of object recognition in peripheral vision, preventing us from fully appreciating cluttered visual scenes. We trained adult human subjects on a crowded orientation discrimination task and investigated whether crowding could be completely eliminated by training. We discovered a two-stage learning process with this training task. In the early stage, when the target and flankers were separated beyond a certain distance, subjects acquired a relatively general ability to break crowding, as evidenced by the fact that the breaking of crowding could transfer to another crowded orientation, even a crowded motion stimulus, although the transfer to the opposite visual hemi-field was weak. In the late stage, like many classical perceptual learning effects, subjects' performance gradually improved and showed specificity to the trained orientation. We also found that, when the target and flankers were spaced too finely, training could only reduce, rather than completely eliminate, the crowding effect. This two-stage learning process illustrates a learning strategy for our brain to deal with the notoriously difficult problem of identifying peripheral objects in clutter. The brain first learned to solve the "easy and general" part of the problem (i.e., improving the processing resolution and segmenting the target and flankers) and then tackle the "difficult and specific" part (i.e., refining the representation of the target).

  8. Revised MITG design, fabrication procedure, and performance predictions

    Energy Technology Data Exchange (ETDEWEB)

    Schock, A.

    1983-01-01

    The design, analysis, and key features of the Modular Isotopic Thermoelectric Generator (MITG) were described in a 1981 IECEC paper; and the design, fabrication, testing, and post-test analysis of test assemblies simulating prototypical MITG modules were described in preceding papers in these proceedings. These analyses succeeded in identifying and explaining the principal causes of thermal-stress problems encountered in the tests, and in confirming the effectiveness of design changes for alleviating them. The present paper presents additional design improvements for solving these and other problems, and describes new thermoelectric material properties generated by independent laboratories over the past two years. Based on these changes and on a revised fabrication procedure, it presents a reoptimization of the MITG design and computes the power-to-weight ratio for the revised design. That ratio is appreciably lower than the 1981 prediction, primarily because of changes in material properties; but it is still much higher than the specific power of current-generation RTGs.

  9. Two-Stage Liver Transplantation with Temporary Porto-Middle Hepatic Vein Shunt

    Directory of Open Access Journals (Sweden)

    Giovanni Varotti

    2010-01-01

    Full Text Available Two-stage liver transplantation (LT has been reported for cases of fulminant liver failure that can lead to toxic hepatic syndrome, or massive hemorrhages resulting in uncontrollable bleeding. Technically, the first stage of the procedure consists of a total hepatectomy with preservation of the recipient's inferior vena cava (IVC, followed by the creation of a temporary end-to-side porto-caval shunt (TPCS. The second stage consists of removing the TPCS and implanting a liver graft when one becomes available. We report a case of a two-stage total hepatectomy and LT in which a temporary end-to-end anastomosis between the portal vein and the middle hepatic vein (TPMHV was performed as an alternative to the classic end-to-end TPCS. The creation of a TPMHV proved technically feasible and showed some advantages compared to the standard TPCS. In cases in which a two-stage LT with side-to-side caval reconstruction is utilized, TPMHV can be considered as a safe and effective alternative to standard TPCS.

  10. Criteria procedure development for tender in construction design

    Directory of Open Access Journals (Sweden)

    Malykha Galina Gennad’evna

    Full Text Available This article deals with the problem of criteria optimization in order to objectively evaluate the experience of an applicant (a project organization and the quality of a design product (project documentation. The methodology to be developed is based on introduction of new evaluation criteria (sub-criteria that in conjunction with the applicable criteria specified by the Law on the Contract System will allow developing the optimal procedure to evaluate competitive bids of the participants in tenders and determining the most appropriate candidate, with whom the contract will be further concluded. The article analyzes the existing criteria and their interaction with each other and describes the specifics of tenders for design in the form of open competition. The list decreases to three criteria, such as "contract price", "quality, functional and environmental characteristics of a procurement facility", "qualification of procurement participants, including availability of financial resources, equipment and other material resources necessary for the execution of the contract material resources, the presence of goodwill, professionals and other employees of a certain experience level". However, in order to upgrade the quality of assurance procedures for the design works to be performed, it was decided to apply new evaluation criteria (sub-criteria components, such as "availability of positive findings of the state out-of-departmental examination that are similar to the subject of competition, on a participant in placement of order", "availability of the certificate on approval of architectural and urban planning decisions that are similar to the subject of competition, on a participant in placement of order", "availability of the permit for the commissioning of facilities that are similar to the subject of competition, on a participant in placement of order", "availability of the contract for designer's supervision with a participant in placement of

  11. Two stage DOA and Fundamental Frequency Estimation based on Subspace Techniques

    DEFF Research Database (Denmark)

    Zhou, Zhenhua; Christensen, Mads Græsbøll; So, Hing-Cheung

    2012-01-01

    optimally weighted harmonic multiple signal classification (MCOW-HMUSIC) estimator is devised for the estimation of fundamental frequencies. Secondly, the spatio- temporal multiple signal classification (ST-MUSIC) estimator is proposed for the estimation of DOA with the estimated frequencies. Statistical......In this paper, the problem of fundamental frequency and direction-of-arrival (DOA) estimation for multi-channel harmonic sinusoidal signal is addressed. The estimation procedure consists of two stages. Firstly, by making use of the subspace technique and Markov-based eigenanalysis, a multi- channel...... evaluation with synthetic signals shows the high accuracy of the proposed methods compared with their non-weighting versions....

  12. Two-Stage Part-Based Pedestrian Detection

    DEFF Research Database (Denmark)

    Møgelmose, Andreas; Prioletti, Antonio; Trivedi, Mohan M.

    2012-01-01

    Detecting pedestrians is still a challenging task for automotive vision system due the extreme variability of targets, lighting conditions, occlusions, and high speed vehicle motion. A lot of research has been focused on this problem in the last 10 years and detectors based on classifiers has...... gained a special place among the different approaches presented. This work presents a state-of-the-art pedestrian detection system based on a two stages classifier. Candidates are extracted with a Haar cascade classifier trained with the DaimlerDB dataset and then validated through part-based HOG...... of several metrics, such as detection rate, false positives per hour, and frame rate. The novelty of this system rely in the combination of HOG part-based approach, tracking based on specific optimized feature and porting on a real prototype....

  13. A two-stage method for inverse medium scattering

    KAUST Repository

    Ito, Kazufumi

    2013-03-01

    We present a novel numerical method to the time-harmonic inverse medium scattering problem of recovering the refractive index from noisy near-field scattered data. The approach consists of two stages, one pruning step of detecting the scatterer support, and one resolution enhancing step with nonsmooth mixed regularization. The first step is strictly direct and of sampling type, and it faithfully detects the scatterer support. The second step is an innovative application of nonsmooth mixed regularization, and it accurately resolves the scatterer size as well as intensities. The nonsmooth model can be efficiently solved by a semi-smooth Newton-type method. Numerical results for two- and three-dimensional examples indicate that the new approach is accurate, computationally efficient, and robust with respect to data noise. © 2012 Elsevier Inc.

  14. Laparoscopic management of a two staged gall bladdertorsion

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Gall bladder torsion (GBT) is a relatively uncommonentity and rarely diagnosed preoperatively. A constantfactor in all occurrences of GBT is a freely mobilegall bladder due to congenital or acquired anomalies.GBT is commonly observed in elderly white females.We report a 77-year-old, Caucasian lady who wasoriginally diagnosed as gall bladder perforation butwas eventually found with a two staged torsion of thegall bladder with twisting of the Riedel's lobe (partof tongue like projection of liver segment 4A). Thistogether, has not been reported in literature, to thebest of our knowledge. We performed laparoscopiccholecystectomy and she had an uneventful postoperativeperiod. GBT may create a diagnostic dilemmain the context of acute cholecystitis. Timely diagnosisand intervention is necessary, with extra care whileoperating as the anatomy is generally distorted. Thefundus first approach can be useful due to alteredanatomy in the region of Calot's triangle. Laparoscopiccholecystectomy has the benefit of early recovery.

  15. Lightweight Concrete Produced Using a Two-Stage Casting Process

    Directory of Open Access Journals (Sweden)

    Jin Young Yoon

    2015-03-01

    Full Text Available The type of lightweight aggregate and its volume fraction in a mix determine the density of lightweight concrete. Minimizing the density obviously requires a higher volume fraction, but this usually causes aggregates segregation in a conventional mixing process. This paper proposes a two-stage casting process to produce a lightweight concrete. This process involves placing lightweight aggregates in a frame and then filling in the remaining interstitial voids with cementitious grout. The casting process results in the lowest density of lightweight concrete, which consequently has low compressive strength. The irregularly shaped aggregates compensate for the weak point in terms of strength while the round-shape aggregates provide a strength of 20 MPa. Therefore, the proposed casting process can be applied for manufacturing non-structural elements and structural composites requiring a very low density and a strength of at most 20 MPa.

  16. TWO-STAGE OCCLUDED OBJECT RECOGNITION METHOD FOR MICROASSEMBLY

    Institute of Scientific and Technical Information of China (English)

    WANG Huaming; ZHU Jianying

    2007-01-01

    A two-stage object recognition algorithm with the presence of occlusion is presented for microassembly. Coarse localization determines whether template is in image or not and approximately where it is, and fine localization gives its accurate position. In coarse localization, local feature, which is invariant to translation, rotation and occlusion, is used to form signatures. By comparing signature of template with that of image, approximate transformation parameter from template to image is obtained, which is used as initial parameter value for fine localization. An objective function, which is a function of transformation parameter, is constructed in fine localization and minimized to realize sub-pixel localization accuracy. The occluded pixels are not taken into account in objective function, so the localization accuracy will not be influenced by the occlusion.

  17. The hybrid two stage anticlockwise cycle for ecological energy conversion

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2016-01-01

    Full Text Available The anticlockwise cycle is commonly used for refrigeration, air conditioning and heat pumps applications. The application of refrigerant in the compression cycle is within the temperature limits of the triple point and the critical point. New refrigerants such as 1234yf or 1234ze have many disadvantages, therefore natural refrigerants application is favourable. The carbon dioxide and water can be applied only in the hybrid two stages cycle. The possibilities of this solutions are shown for refrigerating applications, as well some experimental results of the adsorption-compression double stages cycle, powered with solar collectors are shown. As a high temperature cycle the adsorption system is applied. The low temperature cycle is the compression stage with carbon dioxide as a working fluid. This allows to achieve relatively high COP for low temperature cycle and for the whole system.

  18. Two Stage Assessment of Thermal Hazard in An Underground Mine

    Science.gov (United States)

    Drenda, Jan; Sułkowski, Józef; Pach, Grzegorz; Różański, Zenon; Wrona, Paweł

    2016-06-01

    The results of research into the application of selected thermal indices of men's work and climate indices in a two stage assessment of climatic work conditions in underground mines have been presented in this article. The difference between these two kinds of indices was pointed out during the project entitled "The recruiting requirements for miners working in hot underground mine environments". The project was coordinated by The Institute of Mining Technologies at Silesian University of Technology. It was a part of a Polish strategic project: "Improvement of safety in mines" being financed by the National Centre of Research and Development. Climate indices are based only on physical parameters of air and their measurements. Thermal indices include additional factors which are strictly connected with work, e.g. thermal resistance of clothing, kind of work etc. Special emphasis has been put on the following indices - substitute Silesian temperature (TS) which is considered as the climatic index, and the thermal discomfort index (δ) which belongs to the thermal indices group. The possibility of the two stage application of these indices has been taken into consideration (preliminary and detailed estimation). Based on the examples it was proved that by the application of thermal hazard (detailed estimation) it is possible to avoid the use of additional technical solutions which would be necessary to reduce thermal hazard in particular work places according to the climate index. The threshold limit value for TS has been set, based on these results. It was shown that below TS = 24°C it is not necessary to perform detailed estimation.

  19. S-band gain-flattened EDFA with two-stage double-pass configuration

    Science.gov (United States)

    Fu, Hai-Wei; Xu, Shi-Chao; Qiao, Xue-Guang; Jia, Zhen-An; Liu, Ying-Gang; Zhou, Hong

    2011-11-01

    A gain-flattened S-band erbium-doped fiber amplifier (EDFA) using standard erbium-doped fiber (EDF) is proposed and experimentally demonstrated. The proposed amplifier with two-stage double-pass configuration employs two C-band suppressing filters to obtain the optical gain in S-band. The amplifier provides a maximum signal gain of 41.6 dB at 1524 nm with the corresponding noise figure of 3.8 dB. Furthermore, with a well-designed short-pass filter as a gain flattening filter (GFF), we are able to develop the S-band EDFA with a flattened gain of more than 20 dB in 1504-1524 nm. In the experiment, the two-stage double-pass amplifier configuration improves performance of gain and noise figure compared with the configuration of single-stage double-pass S-band EDFA.

  20. Performance of a highly loaded two stage axial-flow fan

    Science.gov (United States)

    Ruggeri, R. S.; Benser, W. A.

    1974-01-01

    A two-stage axial-flow fan with a tip speed of 1450 ft/sec (442 m/sec) and an overall pressure ratio of 2.8 was designed, built, and tested. At design speed and pressure ratio, the measured flow matched the design value of 184.2 lbm/sec (83.55kg/sec). The adiabatic efficiency at the design operating point was 85.7 percent. The stall margin at design speed was 10 percent. A first-bending-mode flutter of the second-stage rotor blades was encountered near stall at speeds between 77 and 93 percent of design, and also at high pressure ratios at speeds above 105 percent of design. A 5 deg closed reset of the first-stage stator eliminated second-stage flutter for all but a narrow speed range near 90 percent of design.

  1. 自然工质风冷太阳能双级喷射中低温空调制冷系统的设计及性能分析%Design and performance analysis of solar-powered air-cooled two-staged ejector cooling systems with natural refrigerants for middle and low temperature purpose

    Institute of Scientific and Technical Information of China (English)

    卢苇; 陈洪杰; 杨林; 曹聪

    2012-01-01

    依据中低温空调温度要求,分别以水、氨、R290和R600a为工质,设计了额定制冷量为10kW的风冷太阳能双级喷射制冷系统并对其进行变工况性能分析.在获得相同制冷量和室内温度的条件下,水系统最省材料,其次是氨和R290系统,且二者相当,R600a系统最耗材.4种工质系统均具有较强的变工况性能;综合考虑环境温度和太阳辐照度的影响,各系统制冷能力相当.水系统的COP较其他系统的高,且在低太阳辐照度时更明显;其余3个系统COP从高到低依次为氨、R290、R600a.在太阳辐照度较弱地区,使用水喷射制冷系统更合理.%According to the requirement of middle and low temperature air conditioning,the solar-powered air-cooled two-staged ejector cooling system with rated cooling capacity of 10 kW is designed,using water,ammonia,R290 and R600a as working fluids separately. The performance is analyzed. At certain cooling capacity and indoor temperature,the water system is the most material-saving system,followed by the ammonia and R290 ones with equivalent consumption,and the R600a system is the most material-consuming one. The four systems have relatively perfect off-design performance and their cooling capacities are almost the same on comprehensive consideration of the influences of ambient temperature and solar irradiance. Among the four systems,the water system presents higher COP value,the effect of which is more obvious under weaker solar irradiance,followed by ammonia system,R290 and R600a systems. A solar-powered air-cooled ejector refrigeration system with water as working fluid is more suitable for use in the regions with relatively weak solar irradiance.

  2. A design procedure and handling quality criteria for lateral directional flight control systems

    Science.gov (United States)

    Stein, G.; Henke, A. H.

    1972-01-01

    A practical design procedure for aircraft augmentation systems is described based on quadratic optimal control technology and handling-quality-oriented cost functionals. The procedure is applied to the design of a lateral-directional control system for the F4C aircraft. The design criteria, design procedure, and final control system are validated with a program of formal pilot evaluation experiments.

  3. New procedures of ergonomics design in a large oil company.

    Science.gov (United States)

    Alhadeff, Cynthia Mossé; Silva, Rosana Fernandes da; Reis, Márcia Sales dos

    2012-01-01

    This study presents the challenge involved in the negotiation and construction of a standard process in a major petroleum company that has the purpose of guiding the implementation of ergonomic studies in the development of projects, systemising the implementation of ergonomics design. The standard was created by a multi-disciplinary working group consisting of specialists in ergonomics, who work in a number of different areas of the company. The objective was to guide "how to" undertake ergonomics in all projects, taking into consideration the development of the ergonomic appraisals of work. It also established that all the process, in each project phase, should be accompanied by a specialist in ergonomics. This process as an innovation in the conception of projects in this company, signals a change of culture, and, for this reason requires broad dissemination throughout the several company leadership levels, and training of professionals in projects of ergonomics design. An implementation plan was also prepared and approved by the corporate governance, complementing the proposed challenge. In this way, this major oil company will implement new procedures of ergonomics design to promote health, safety, and wellbeing of the workforce, besides improving the performance and reliability of its systems and processes.

  4. Development of Two-Stage Stirling Cooler for ASTRO-F

    Science.gov (United States)

    Narasaki, K.; Tsunematsu, S.; Ootsuka, K.; Kyoya, M.; Matsumoto, T.; Murakami, H.; Nakagawa, T.

    2004-06-01

    A two-stage small Stirling cooler has been developed and tested for the infrared astronomical satellite ASTRO-F that is planned to be launched by Japanese M-V rocket in 2005. ASTRO-F has a hybrid cryogenic system that is a combination of superfluid liquid helium (HeII) and two-stage Stirling coolers. The mechanical cooler has a two-stage displacer driven by a linear motor in a cold head and a new linear-ball-bearing system for the piston-supporting structure in a compressor. The linear-ball-bearing supporting system achieves the piston clearance seal, the long piston-stroke operation and the low frequency operation. The typical cooling power is 200 mW at 20 K and the total input power to the compressor and the cold head is below 90 W without driver electronics. The engineering, the prototype and the flight models of the cooler have been fabricated and evaluated to verify the capability for ASTRO-F. This paper describes the design of the cooler and the results from verification tests including cooler performance test, thermal vacuum test, vibration test and lifetime test.

  5. A two-stage Stirling-type pulse tube cryocooler with a cold inertance tube

    Science.gov (United States)

    Gan, Z. H.; Fan, B. Y.; Wu, Y. Z.; Qiu, L. M.; Zhang, X. J.; Chen, G. B.

    2010-06-01

    A thermally coupled two-stage Stirling-type pulse tube cryocooler (PTC) with inertance tubes as phase shifters has been designed, manufactured and tested. In order to obtain a larger phase shift at the low acoustic power of about 2.0 W, a cold inertance tube as well as a cold reservoir for the second stage, precooled by the cold end of the first stage, was introduced into the system. The transmission line model was used to calculate the phase shift produced by the cold inertance tube. Effect of regenerator material, geometry and charging pressure on the performance of the second stage of the two-stage PTC was investigated based on the well known regenerator model REGEN. Experimental results of the two-stage PTC were carried out with an emphasis on the performance of the second stage. A lowest cooling temperature of 23.7 K and 0.50 W at 33.9 K were obtained with an input electric power of 150.0 W and an operating frequency of 40 Hz.

  6. Industrial demonstration plant for the gasification of herb residue by fluidized bed two-stage process.

    Science.gov (United States)

    Zeng, Xi; Shao, Ruyi; Wang, Fang; Dong, Pengwei; Yu, Jian; Xu, Guangwen

    2016-04-01

    A fluidized bed two-stage gasification process, consisting of a fluidized-bed (FB) pyrolyzer and a transport fluidized bed (TFB) gasifier, has been proposed to gasify biomass for fuel gas production with low tar content. On the basis of our previous fundamental study, an autothermal two-stage gasifier has been designed and built for gasify a kind of Chinese herb residue with a treating capacity of 600 kg/h. The testing data in the operational stable stage of the industrial demonstration plant showed that when keeping the reaction temperatures of pyrolyzer and gasifier respectively at about 700 °C and 850 °C, the heating value of fuel gas can reach 1200 kcal/Nm(3), and the tar content in the produced fuel gas was about 0.4 g/Nm(3). The results from this pilot industrial demonstration plant fully verified the feasibility and technical features of the proposed FB two-stage gasification process.

  7. Multiobjective Two-Stage Stochastic Programming Problems with Interval Discrete Random Variables

    Directory of Open Access Journals (Sweden)

    S. K. Barik

    2012-01-01

    Full Text Available Most of the real-life decision-making problems have more than one conflicting and incommensurable objective functions. In this paper, we present a multiobjective two-stage stochastic linear programming problem considering some parameters of the linear constraints as interval type discrete random variables with known probability distribution. Randomness of the discrete intervals are considered for the model parameters. Further, the concepts of best optimum and worst optimum solution are analyzed in two-stage stochastic programming. To solve the stated problem, first we remove the randomness of the problem and formulate an equivalent deterministic linear programming model with multiobjective interval coefficients. Then the deterministic multiobjective model is solved using weighting method, where we apply the solution procedure of interval linear programming technique. We obtain the upper and lower bound of the objective function as the best and the worst value, respectively. It highlights the possible risk involved in the decision-making tool. A numerical example is presented to demonstrate the proposed solution procedure.

  8. Characterization of component interactions in two-stage axial turbine

    Directory of Open Access Journals (Sweden)

    Adel Ghenaiet

    2016-08-01

    Full Text Available This study concerns the characterization of both the steady and unsteady flows and the analysis of stator/rotor interactions of a two-stage axial turbine. The predicted aerodynamic performances show noticeable differences when simulating the turbine stages simultaneously or separately. By considering the multi-blade per row and the scaling technique, the Computational fluid dynamics (CFD produced better results concerning the effect of pitchwise positions between vanes and blades. The recorded pressure fluctuations exhibit a high unsteadiness characterized by a space–time periodicity described by a double Fourier decomposition. The Fast Fourier Transform FFT analysis of the static pressure fluctuations recorded at different interfaces reveals the existence of principal harmonics and their multiples, and each lobed structure of pressure wave corresponds to the number of vane/blade count. The potential effect is seen to propagate both upstream and downstream of each blade row and becomes accentuated at low mass flow rates. Between vanes and blades, the potential effect is seen to dominate the quasi totality of blade span, while downstream the blades this effect seems to dominate from hub to mid span. Near the shroud the prevailing effect is rather linked to the blade tip flow structure.

  9. A continuous two stage solar coal gasification system

    Science.gov (United States)

    Mathur, V. K.; Breault, R. W.; Lakshmanan, S.; Manasse, F. K.; Venkataramanan, V.

    The characteristics of a two-stage fluidized-bed hybrid coal gasification system to produce syngas from coal, lignite, and peat are described. Devolatilization heat of 823 K is supplied by recirculating gas heated by a solar receiver/coal heater. A second-stage gasifier maintained at 1227 K serves to crack remaining tar and light oil to yield a product free from tar and other condensables, and sulfur can be removed by hot clean-up processes. CO is minimized because the coal is not burned with oxygen, and the product gas contains 50% H2. Bench scale reactors consist of a stage I unit 0.1 m in diam which is fed coal 200 microns in size. A stage II reactor has an inner diam of 0.36 m and serves to gasify the char from stage I. A solar power source of 10 kWt is required for the bench model, and will be obtained from a central receiver with quartz or heat pipe configurations for heat transfer.

  10. Characterization of component interactions in two-stage axial turbine

    Institute of Scientific and Technical Information of China (English)

    Adel Ghenaiet; Kaddour Touil

    2016-01-01

    This study concerns the characterization of both the steady and unsteady flows and the analysis of stator/rotor interactions of a two-stage axial turbine. The predicted aerodynamic perfor-mances show noticeable differences when simulating the turbine stages simultaneously or sepa-rately. By considering the multi-blade per row and the scaling technique, the Computational fluid dynamics (CFD) produced better results concerning the effect of pitchwise positions between vanes and blades. The recorded pressure fluctuations exhibit a high unsteadiness characterized by a space–time periodicity described by a double Fourier decomposition. The Fast Fourier Transform FFT analysis of the static pressure fluctuations recorded at different interfaces reveals the existence of principal harmonics and their multiples, and each lobed structure of pressure wave corresponds to the number of vane/blade count. The potential effect is seen to propagate both upstream and downstream of each blade row and becomes accentuated at low mass flow rates. Between vanes and blades, the potential effect is seen to dominate the quasi totality of blade span, while down-stream the blades this effect seems to dominate from hub to mid span. Near the shroud the prevail-ing effect is rather linked to the blade tip flow structure.

  11. Two stages kinetics of municipal solid waste inoculation composting processes

    Institute of Scientific and Technical Information of China (English)

    XI Bei-dou1; HUANG Guo-he; QIN Xiao-sheng; LIU Hong-liang

    2004-01-01

    In order to understand the key mechanisms of the composting processes, the municipal solid waste(MSW) composting processes were divided into two stages, and the characteristics of typical experimental scenarios from the viewpoint of microbial kinetics was analyzed. Through experimentation with advanced composting reactor under controlled composting conditions, several equations were worked out to simulate the degradation rate of the substrate. The equations showed that the degradation rate was controlled by concentration of microbes in the first stage. The degradation rates of substrates of inoculation Run A, B, C and Control composting systems were 13.61 g/(kg·h), 13.08 g/(kg·h), 15.671 g/(kg·h), and 10.5 g/(kg·h), respectively. The value of Run C is around 1.5 times higher than that of Control system. The decomposition rate of the second stage is controlled by concentration of substrate. Although the organic matter decomposition rates were similar to all Runs, inoculation could reduce the values of the half velocity coefficient and could be more efficient to make the composting stable. Particularly. For Run C, the decomposition rate is high in the first stage, and is low in the second stage. The results indicated that the inoculation was efficient for the composting processes.

  12. Two-stage vs single-stage management for concomitant gallstones and common bile duct stones

    Institute of Scientific and Technical Information of China (English)

    Jiong Lu; Yao Cheng; Xian-Ze Xiong; Yi-Xin Lin; Si-Jia Wu; Nan-Sheng Cheng

    2012-01-01

    AIM:To evaluate the safety and effectiveness of two-stage vs single-stage management for concomitant gallstones and common bile duct stones.METHODS:Four databases,including PubMed,Embase,the Cochrane Central Register of Controlled Trials and the Science Citation Index up to September 2011,were searched to identify all randomized controlled trials (RCTs).Data were extracted from the studies by two independent reviewers.The primary outcomes were stone clearance from the common bile duct,postoperative morbidity and mortality.The secondary outcomes were conversion to other procedures,number of procedures per patient,length of hospital stay,total operative time,hospitalization charges,patient acceptance and quality of life scores.RESULTS:Seven eligible RCTs [five trials (n =621)comparing preoperative endoscopic retrograde cholangiopancreatography (ERCP)/endoscopic sphincterotomy (EST) + laparoscopic cholecystectomy (LC) with LC +laparoscopic common bile duct exploration (LCBDE);two trials (n =166) comparing postoperative ERCP/EST + LC with LC + LCBDE],composed of 787 patients in total,were included in the final analysis.The metaanalysis detected no statistically significant difference between the two groups in stone clearance from the common bile duct [risk ratios (RR) =-0.10,95% confidence intervals (CI):-0.24 to 0.04,P =0.17],postoperative morbidity (RR =0.79,95% CI:0.58 to 1.10,P =0.16),mortality (RR =2.19,95% CI:0.33 to 14.67,P =0.42),conversion to other procedures (RR =1.21,95% CI:0.54 to 2.70,P =0.39),length of hospital stay (MD =0.99,95% CI:-1.59 to 3.57,P =0.45),total operative time (MD =12.14,95% CI:-1.83 to 26.10,P =0.09).Two-stage (LC + ERCP/EST) management clearly required more procedures per patient than single-stage (LC + LCBDE) management.CONCLUSION:Single-stage management is equivalent to two-stage management but requires fewer procedures.However,patient's condition,operator's expertise and local resources should be taken into account in

  13. Considerations Regarding Age at Surgery and Fistula Incidence Using One- and Two-stage Closure for Cleft Palate

    Directory of Open Access Journals (Sweden)

    Simona Stoicescu

    2013-12-01

    Full Text Available Introduction: Although cleft lip and palate (CLP is one of the most common congenital malformations, occurring in 1 in 700 live births, there is still no generally accepted treatment protocol. Numerous surgical techniques have been described for cleft palate repair; these techniques can be divided into one-stage (one operation cleft palate repair and two-stage cleft palate closure. The aim of this study is to present our cleft palate team experience in using the two-stage cleft palate closure and the clinical outcomes in terms of oronasal fistula rate. Material and methods: A retrospective analysis was performed on medical records of 80 patients who underwent palate repair over a five-year period, from 2008 to 2012. All cleft palate patients were incorporated. Information on patient’s gender, cleft type, age at repair, one- or two-stage cleft palate repair were collected and analyzed. Results: Fifty-three (66% and twenty-seven (34% patients underwent two-stage and one-stage repair, respectively. According to Veau classification, more than 60% of them were Veau III and IV, associating cleft lip to cleft palate. Fistula occurred in 34% of the two-stage repairs versus 7% of one-stage repairs, with an overall incidence of 24%. Conclusions: Our study has shown that a two-stage cleft palate closure has a higher rate of fistula formation when compared with the one-stage repair. Two-stage repair is the protocol of choice in wide complete cleft lip and palate cases, while one-stage procedure is a good option for cleft palate alone, or some specific cleft lip and palate cases (narrow cleft palate, older age at surgery

  14. Damage tolerance design procedures for an automotive composite

    Energy Technology Data Exchange (ETDEWEB)

    Corum, J.M.; Battiste, R.L.

    1998-11-01

    Among the durability issues of concern in the use of composites in automobile structures is the damaging effects that low-energy impacts (e.g., tool drops and roadway kickups) might have on strength and stiffness. This issue was experimentally investigated, and recommended design evaluation procedures were developed for a candidate automotive structural composite--a structural reaction injection-molded polyurethane reinforced with continuous strand, swirl-mat E-glass fibers. Two test facilities were built to cover the range of impacts of interest--a pendulum device to characterize the effects of relative heavy objects at low velocities and an air gun to characterize the effects of relatively light objects at higher velocities. In all cases, the test specimen was a 9 x 9 x 1/8-in.-thick plate clamped on an 8-in.-diam circle. Sixty-five impact tests were performed. Included were tests using various impactor sizes and weights, tests at {minus}40 F, and tests on specimens that has been presoaked in water or exposed to battery acid. Damage areas were determined using ultrasonic C-scans, and the resulting areas were found to correlate with the quantity impactor mass to a power times velocity. A design curve was derived from the correlation and validated using dropped brick tests. To evaluate strength and stiffness reductions, the impacted plate specimens were cut into tensile, compressive, and fatigue test specimens that were used to determine reductions as a function of damage area. It was found that for design purposes, the strength reduction could be determined by representing the damage area by a circular hole of equivalent area.

  15. Evaluation of vertical profiles to design continuous descent approach procedure

    Science.gov (United States)

    Pradeep, Priyank

    The current research focuses on predictability, variability and operational feasibility aspect of Continuous Descent Approach (CDA), which is among the key concepts of the Next Generation Air Transportation System (NextGen). The idle-thrust CDA is a fuel economical, noise and emission abatement procedure, but requires increased separation to accommodate for variability and uncertainties in vertical and speed profiles of arriving aircraft. Although a considerable amount of researches have been devoted to the estimation of potential benefits of the CDA, only few have attempted to explain the predictability, variability and operational feasibility aspect of CDA. The analytical equations derived using flight dynamics and Base of Aircraft and Data (BADA) Total Energy Model (TEM) in this research gives insight into dependency of vertical profile of CDA on various factors like wind speed and gradient, weight, aircraft type and configuration, thrust settings, atmospheric factors (deviation from ISA (DISA), pressure and density of the air) and descent speed profile. Application of the derived equations to idle-thrust CDA gives an insight into sensitivity of its vertical profile to multiple factors. This suggests fixed geometric flight path angle (FPA) CDA has higher degree of predictability and lesser variability at the cost of non-idle and low thrust engine settings. However, with optimized design this impact can be overall minimized. The CDA simulations were performed using Future ATM Concept Evaluation Tool (FACET) based on radar-track and aircraft type data (BADA) of the real air-traffic to some of the busiest airports in the USA (ATL, SFO and New York Metroplex (JFK, EWR and LGA)). The statistical analysis of the vertical profiles of CDA shows 1) mean geometric FPAs derived from various simulated vertical profiles are consistently shallower than 3° glideslope angle and 2) high level of variability in vertical profiles of idle-thrust CDA even in absence of

  16. SQL/JavaScript Hybrid Worms As Two-stage Quines

    CERN Document Server

    Orlicki, José I

    2009-01-01

    Delving into present trends and anticipating future malware trends, a hybrid, SQL on the server-side, JavaScript on the client-side, self-replicating worm based on two-stage quines was designed and implemented on an ad-hoc scenario instantiating a very common software pattern. The proof of concept code combines techniques seen in the wild, in the form of SQL injections leading to cross-site scripting JavaScript inclusion, and seen in the laboratory, in the form of SQL quines propa- gated via RFIDs, resulting in a hybrid code injection. General features of hybrid worms are also discussed.

  17. Performance of the SITP 35K two-stage Stirling cryocooler

    Science.gov (United States)

    Liu, Dongyu; Li, Ao; Li, Shanshan; Wu, Yinong

    2010-04-01

    This paper presents the design, development, optimization experiment and performance of the SITP two-stage Stirling cryocooler. The geometry size of the cooler, especially the diameter and length of the regenerator were analyzed. Operating parameters by experiments were optimized to maximize the second stage cooling performance. In the test the cooler was operated at various drive frequency, phase shift between displacer and piston, fill pressure. The experimental results indicate that the cryocooler has a higher efficiency with a performance of 0.85W at 35K with a compressor input power of 56W at a phase shift of 65°, an operating frequency of 40Hz, 1MPa fill pressure.

  18. Space Station Freedom carbon dioxide removal assembly two-stage rotary sliding vane pump

    Science.gov (United States)

    Matteau, Dennis

    1992-07-01

    The design and development of a positive displacement pump selected to operate as an essential part of the carbon dioxide removal assembly (CDRA) are described. An oilless two-stage rotary sliding vane pump was selected as the optimum concept to meet the CDRA application requirements. This positive displacement pump is characterized by low weight and small envelope per unit flow, ability to pump saturated gases and moderate amount of liquid, small clearance volumes, and low vibration. It is easily modified to accommodate several stages on a single shaft optimizing space and weight, which makes the concept ideal for a range of demanding space applications.

  19. Modelling of two-stage anaerobic digestion using the IWA Anaerobic Digestion Model No. 1 (ADM1).

    Science.gov (United States)

    Blumensaat, F; Keller, J

    2005-01-01

    The aim of the study presented was to implement a process model to simulate the dynamic behaviour of a pilot-scale process for anaerobic two-stage digestion of sewage sludge. The model implemented was initiated to support experimental investigations of the anaerobic two-stage digestion process. The model concept implemented in the simulation software package MATLAB/Simulink is a derivative of the IWA Anaerobic Digestion Model No.1 (ADM1) that has been developed by the IWA task group for mathematical modelling of anaerobic processes. In the present study the original model concept has been adapted and applied to replicate a two-stage digestion process. Testing procedures, including balance checks and 'benchmarking' tests were carried out to verify the accuracy of the implementation. These combined measures ensured a faultless model implementation without numerical inconsistencies. Parameters for both, the thermophilic and the mesophilic process stage, have been estimated successfully using data from lab-scale experiments described in literature. Due to the high number of parameters in the structured model, it was necessary to develop a customised procedure that limited the range of parameters to be estimated. The accuracy of the optimised parameter sets has been assessed against experimental data from pilot-scale experiments. Under these conditions, the model predicted reasonably well the dynamic behaviour of a two-stage digestion process in pilot scale.

  20. Model of Procedure Usage – Results from a Qualitative Study to Inform Design of Computer-Based Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Johanna H Oxstrand; Katya L Le Blanc

    2012-07-01

    The nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. As a step toward the goal of improving procedure use performance, researchers, together with the nuclear industry, have been looking at replacing the current paper-based procedures with computer-based procedure systems. The concept of computer-based procedures is not new by any means; however most research has focused on procedures used in the main control room. Procedures reviewed in these efforts are mainly emergency operating procedures and normal operating procedures. Based on lessons learned for these previous efforts we are now exploring a more unknown application for computer based procedures - field procedures, i.e. procedures used by nuclear equipment operators and maintenance technicians. The Idaho National Laboratory, the Institute for Energy Technology, and participants from the U.S. commercial nuclear industry are collaborating in an applied research effort with the objective of developing requirements and specifications for a computer-based procedure system to be used by field operators. The goal is to identify the types of human errors that can be mitigated by using computer-based procedures and how to best design the computer-based procedures to do this. The underlying philosophy in the research effort is “Stop – Start – Continue”, i.e. what features from the use of paper-based procedures should we not incorporate (Stop), what should we keep (Continue), and what new features or work processes should be added (Start). One step in identifying the Stop – Start – Continue was to conduct a baseline study where affordances related to the current usage of paper-based procedures were identified. The purpose of the study was to develop a model of paper based procedure use which will help to identify desirable features for computer based procedure prototypes. Affordances such as note taking, markups

  1. Two-stage estimation for multivariate recurrent event data with a dependent terminal event.

    Science.gov (United States)

    Chen, Chyong-Mei; Chuang, Ya-Wen; Shen, Pao-Sheng

    2015-03-01

    Recurrent event data arise in longitudinal follow-up studies, where each subject may experience the same type of events repeatedly. The work in this article is motivated by the data from a study of repeated peritonitis for patients on peritoneal dialysis. Due to the aspects of medicine and cost, the peritonitis cases were classified into two types: Gram-positive and non-Gram-positive peritonitis. Further, since the death and hemodialysis therapy preclude the occurrence of recurrent events, we face multivariate recurrent event data with a dependent terminal event. We propose a flexible marginal model, which has three characteristics: first, we assume marginal proportional hazard and proportional rates models for terminal event time and recurrent event processes, respectively; second, the inter-recurrences dependence and the correlation between the multivariate recurrent event processes and terminal event time are modeled through three multiplicative frailties corresponding to the specified marginal models; third, the rate model with frailties for recurrent events is specified only on the time before the terminal event. We propose a two-stage estimation procedure for estimating unknown parameters. We also establish the consistency of the two-stage estimator. Simulation studies show that the proposed approach is appropriate for practical use. The methodology is applied to the peritonitis cohort data that motivated this study. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Two-Stage Orthogonal Least Squares Methods for Neural Network Construction.

    Science.gov (United States)

    Zhang, Long; Li, Kang; Bai, Er-Wei; Irwin, George W

    2015-08-01

    A number of neural networks can be formulated as the linear-in-the-parameters models. Training such networks can be transformed to a model selection problem where a compact model is selected from all the candidates using subset selection algorithms. Forward selection methods are popular fast subset selection approaches. However, they may only produce suboptimal models and can be trapped into a local minimum. More recently, a two-stage fast recursive algorithm (TSFRA) combining forward selection and backward model refinement has been proposed to improve the compactness and generalization performance of the model. This paper proposes unified two-stage orthogonal least squares methods instead of the fast recursive-based methods. In contrast to the TSFRA, this paper derives a new simplified relationship between the forward and the backward stages to avoid repetitive computations using the inherent orthogonal properties of the least squares methods. Furthermore, a new term exchanging scheme for backward model refinement is introduced to reduce computational demand. Finally, given the error reduction ratio criterion, effective and efficient forward and backward subset selection procedures are proposed. Extensive examples are presented to demonstrate the improved model compactness constructed by the proposed technique in comparison with some popular methods.

  3. Right Axillary Sweating After Left Thoracoscopic Sypathectomy in Two-Stage Surgery

    Directory of Open Access Journals (Sweden)

    Berkant Ozpolat

    2013-06-01

    Full Text Available One stage bilateral or two stage unilateral video assisted thoracoscopic sympathectomy could be performed in the treatment of primary focal hyperhidrosis. Here we present a case with compensatory sweating of contralateral side after a two stage operation.

  4. The Two-stage Constrained Equal Awards and Losses Rules for Multi-Issue Allocation Situation

    NARCIS (Netherlands)

    Lorenzo-Freire, S.; Casas-Mendez, B.; Hendrickx, R.L.P.

    2005-01-01

    This paper considers two-stage solutions for multi-issue allocation situations.Characterisations are provided for the two-stage constrained equal awards and constrained equal losses rules, based on the properties of composition and path independence.

  5. Engineering Students Designing a Statistical Procedure for Quantifying Variability

    Science.gov (United States)

    Hjalmarson, Margret A.

    2007-01-01

    The study examined first-year engineering students' responses to a statistics task that asked them to generate a procedure for quantifying variability in a data set from an engineering context. Teams used technological tools to perform computations, and their final product was a ranking procedure. The students could use any statistical measures,…

  6. Using Errors to Teach through a Two-Staged, Structured Review: Peer-Reviewed Quizzes and "What's Wrong with Me?"

    Science.gov (United States)

    Coppola, Brian P.; Pontrello, Jason K.

    2014-01-01

    Using errors as a method of learning has been made explicit through a two-staged peer review and discussion. During organic chemistry discussion sessions, quizzes are followed by a structured peer review designed to help students identify and discuss student errors. After the face-to-face discussion, a second stage of review involves analyzing and…

  7. Two staged incentive contract focused on efficiency and innovation matching in critical chain project management

    Directory of Open Access Journals (Sweden)

    Min Zhang

    2014-09-01

    Full Text Available Purpose: The purpose of this paper is to define the relative optimal incentive contract to effectively encourage employees to improve work efficiency while actively implementing innovative behavior. Design/methodology/approach: This paper analyzes a two staged incentive contract coordinated with efficiency and innovation in Critical Chain Project Management using learning real options, based on principle-agent theory. The situational experiment is used to analyze the validity of the basic model. Finding: The two staged incentive scheme is more suitable for employees to create and implement learning real options, which will throw themselves into innovation process efficiently in Critical Chain Project Management. We prove that the combination of tolerance for early failure and reward for long-term success is effective in motivating innovation. Research limitations/implications: We do not include the individual characteristics of uncertain perception, which might affect the consistency of external validity. The basic model and the experiment design need to improve. Practical Implications: The project managers should pay closer attention to early innovation behavior and monitoring feedback of competition time in the implementation of Critical Chain Project Management. Originality/value: The central contribution of this paper is the theoretical and experimental analysis of incentive schemes for innovation in Critical Chain Project Management using the principal-agent theory, to encourage the completion of CCPM methods as well as imitative free-riding on the creative ideas of other members in the team.

  8. Two-Stage Exams Improve Student Learning in an Introductory Geology Course: Logistics, Attendance, and Grades

    Science.gov (United States)

    Knierim, Katherine; Turner, Henry; Davis, Ralph K.

    2015-01-01

    Two-stage exams--where students complete part one of an exam closed book and independently and part two is completed open book and independently (two-stage independent, or TS-I) or collaboratively (two-stage collaborative, or TS-C)--provide a means to include collaborative learning in summative assessments. Collaborative learning has been shown to…

  9. Heuristic for Critical Machine Based a Lot Streaming for Two-Stage Hybrid Production Environment

    Science.gov (United States)

    Vivek, P.; Saravanan, R.; Chandrasekaran, M.; Pugazhenthi, R.

    2017-03-01

    Lot streaming in Hybrid flowshop [HFS] is encountered in many real world problems. This paper deals with a heuristic approach for Lot streaming based on critical machine consideration for a two stage Hybrid Flowshop. The first stage has two identical parallel machines and the second stage has only one machine. In the second stage machine is considered as a critical by valid reasons these kind of problems is known as NP hard. A mathematical model developed for the selected problem. The simulation modelling and analysis were carried out in Extend V6 software. The heuristic developed for obtaining optimal lot streaming schedule. The eleven cases of lot streaming were considered. The proposed heuristic was verified and validated by real time simulation experiments. All possible lot streaming strategies and possible sequence under each lot streaming strategy were simulated and examined. The heuristic consistently yielded optimal schedule consistently in all eleven cases. The identification procedure for select best lot streaming strategy was suggested.

  10. A surrogate based multistage-multilevel optimization procedure for multidisciplinary design optimization

    NARCIS (Netherlands)

    Yao, W.; Chen, X.; Ouyang, Q.; Van Tooren, M.

    2011-01-01

    Optimization procedure is one of the key techniques to address the computational and organizational complexities of multidisciplinary design optimization (MDO). Motivated by the idea of synthetically exploiting the advantage of multiple existing optimization procedures and meanwhile complying with

  11. [Two-stage surgical treatment of urethral stenosis].

    Science.gov (United States)

    Aboutaieb, R; Joual, A; El Moussaoui, A; El Mrini, M; Benjelloun, S

    1995-01-01

    We analysed the results of two-operation procedures for cutaneous urethroplasty performed over a 10 year period. From 1983 to 1993, 44 patients had a Leadbetter urethroplasty. The indication in all cases was stenosis of the bulbal or bulbomenbranous urethra complicated by urethro-cutaneous fistula. After the first operation, 10 patients (22.7%) had a stenosis of one or both of the urethrostomy orifices, requiring one or more further procedures. The second operation concerned 18 patients (40.9%) and gave goods results in 10 (55.5%). Poor results were due to recurrence of the stenosis in 3 cases (16.6%), perineal suppuration in 1 (5.5%), failure of the skin plasty in 1 (5.5%) and formation of a stenosis by a tuft of hair in 1 (5.5%). Finally, 2 patients were lost to follow-up. Mean interval between operations was 8 months. It appears, despite the drawbacks and uncertain results, that sequential operations for cutaneous urethroplasty are indicated when stenosis of the urethra is complicated by fistulization or perineal infection.

  12. 48 CFR 36.301 - Use of two-phase design-build selection procedures.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Use of two-phase design... ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Two-Phase Design-Build Selection Procedures 36.301 Use of two-phase design-build selection procedures....

  13. 42 CFR 5.3 - Procedures for designation of health professional(s) shortage areas.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Procedures for designation of health professional(s) shortage areas. 5.3 Section 5.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS DESIGNATION OF HEALTH PROFESSIONAL(S) SHORTAGE AREAS § 5.3 Procedures for designation of health professional(s)...

  14. Two-stage high frequency pulse tube cooler for refrigeration at 25 K

    CERN Document Server

    Dietrich, M

    2009-01-01

    A two-stage Stirling-type U-shape pulse tube cryocooler driven by a 10 kW-class linear compressor was designed, built and tested. A special feature of the cold head is the absence of a heat exchanger at the cold end of the first stage, since the intended application requires no cooling power at an intermediate temperature. Simulations where done using Sage-software to find optimum operating conditions and cold head geometry. Flow-impedance matching was required to connect the compressor designed for 60 Hz operation to the 40 Hz cold head. A cooling power of 12.9 W at 25 K with an electrical input power of 4.6 kW has been achieved up to now. The lowest temperature reached is 13.7 K.

  15. a Remote Liquid Target Loading System for a Two-Stage Gas Gun

    Science.gov (United States)

    Gibson, L. L.; Bartram, B.; Dattelbaum, D. M.; Sheffield, S. A.; Stahl, D. B.

    2009-12-01

    A Remote Liquid Loading System (RLLS) was designed and tested for the application of loading high-hazard liquid materials into instrumented target cells for gas gun-driven plate impact experiments. These high hazard liquids tend to react with confining materials in a short period of time, degrading target assemblies and potentially building up pressure through the evolution of gas in the reactions. Therefore, the ability to load a gas gun target immediately prior to gun firing provides the most stable and reliable target fielding approach. We present the design and evaluation of an RLLS built for the LANL two-stage gas gun. The system has been used successfully to interrogate the shock initiation behavior of ˜98 wt% percent hydrogen peroxide (H2O2) solutions, using embedded electromagnetic gauges for measurement of shock wave profiles in-situ.

  16. Design Reconstitution Program Plan and procedures for K Basins

    Energy Technology Data Exchange (ETDEWEB)

    Laney, T.

    1995-01-12

    This document establishes a systematic program to establish, organize, and document the design basis and design requirement information for the K Basins where existing design information is inadequate. The Design Reconstitution Program involves identifying and retrieving design information from identified source documents; evaluating, verifying, and validating the design information; resolving discrepancies; regenerating missing critical design information; and preparing and issuing a summary document of the design information. Upon completion, the design requirements shall be evaluated with the facility as-found configuration to verify the adequacy of appropriate design requirements with the as-found configuration and to document and resolve any discovered discrepancies. Once the design requirement (design analysis, calculation, design basis) comparison is made and discrepancies resolved (dispositioned, implemented, and incorporated as required), the as-found condition of a drawing then becomes an as-built drawing that is released into the engineering release system. This as-built drawing is then the accurate accounting of the field configuration that is consistent with the design requirements (recovered through the design reconstitution program) and is used with high confidence to make valid engineering, operational, and maintenance decisions.

  17. A two-stage series diode for intense large-area moderate pulsed X rays production

    Science.gov (United States)

    Lai, Dingguo; Qiu, Mengtong; Xu, Qifu; Su, Zhaofeng; Li, Mo; Ren, Shuqing; Huang, Zhongliang

    2017-01-01

    This paper presents a method for moderate pulsed X rays produced by a series diode, which can be driven by high voltage pulse to generate intense large-area uniform sub-100-keV X rays. A two stage series diode was designed for Flash-II accelerator and experimentally investigated. A compact support system of floating converter/cathode was invented, the extra cathode is floating electrically and mechanically, by withdrawing three support pins several milliseconds before a diode electrical pulse. A double ring cathode was developed to improve the surface electric field and emission stability. The cathode radii and diode separation gap were optimized to enhance the uniformity of X rays and coincidence of the two diode voltages based on the simulation and theoretical calculation. The experimental results show that the two stage series diode can work stably under 700 kV and 300 kA, the average energy of X rays is 86 keV, and the dose is about 296 rad(Si) over 615 cm2 area with uniformity 2:1 at 5 cm from the last converter. Compared with the single diode, the average X rays' energy reduces from 132 keV to 88 keV, and the proportion of sub-100-keV photons increases from 39% to 69%.

  18. A separate two-stage pulse tube cooler working at liquid helium temperature

    Institute of Scientific and Technical Information of China (English)

    QIU Limin; HE Yonglin; GAN Zhihua; WAN Laihong; CHEN Guobang

    2005-01-01

    A novel 4 K separate two-stage pulse tube cooler (PTC) was designed and tested. The cooler consists of two separate pulse tube coolers, in which the cold end of the first stage regenerator is thermally connected with the middle part of the second regenerator. Compared to the traditional coupled multi-stage pulse tube cooler, the mutual interference between stages can be significantly eliminated. The lowest refrigeration temperature obtained at the first stage pulse tube was 13.8 K. This is a new record for single stage PTC. With two compressors and two rotary valves driving mode, the separate two-stage PTC obtained a refrigeration temperature of 2.5 K at the second stage. Cooling capacities of 508 mW at 4.2 K and 15 W at 37.5 K were achieved simultaneously. A one-compressor and one-rotary valve driving mode has been proposed to further simplify the structure of separate type PTC.

  19. Development and optimization of a two-stage gasifier for heat and power production

    Science.gov (United States)

    Kosov, V. V.; Zaichenko, V. M.

    2016-11-01

    The major methods of biomass thermal conversion are combustion in excess oxygen, gasification in reduced oxygen, and pyrolysis in the absence of oxygen. The end products of these methods are heat, gas, liquid and solid fuels. From the point of view of energy production, none of these methods can be considered optimal. A two-stage thermal conversion of biomass based on pyrolysis as the first stage and pyrolysis products cracking as the second stage can be considered the optimal method for energy production that allows obtaining synthesis gas consisting of hydrogen and carbon monoxide and not containing liquid or solid particles. On the base of the two stage cracking technology, there was designed an experimental power plant of electric power up to 50 kW. The power plant consists of a thermal conversion module and a gas engine power generator adapted for operation on syngas. Purposes of the work were determination of an optimal operation temperature of the thermal conversion module and an optimal mass ratio of processed biomass and charcoal in cracking chamber of the thermal conversion module. Experiments on the pyrolysis products cracking at various temperatures show that the optimum cracking temperature is equal to 1000 °C. From the results of measuring the volume of gas produced in different mass ratios of charcoal and wood biomass processed, it follows that the maximum volume of the gas in the range of the mass ratio equal to 0.5-0.6.

  20. Numerical simulation of municipal solid waste combustion in a novel two-stage reciprocating incinerator.

    Science.gov (United States)

    Huai, X L; Xu, W L; Qu, Z Y; Li, Z G; Zhang, F P; Xiang, G M; Zhu, S Y; Chen, G

    2008-01-01

    A mathematical model was presented in this paper for the combustion of municipal solid waste in a novel two-stage reciprocating grate furnace. Numerical simulations were performed to predict the temperature, the flow and the species distributions in the furnace, with practical operational conditions taken into account. The calculated results agree well with the test data, and the burning behavior of municipal solid waste in the novel two-stage reciprocating incinerator can be demonstrated well. The thickness of waste bed, the initial moisture content, the excessive air coefficient and the secondary air are the major factors that influence the combustion process. If the initial moisture content of waste is high, both the heat value of waste and the temperature inside incinerator are low, and less oxygen is necessary for combustion. The air supply rate and the primary air distribution along the grate should be adjusted according to the initial moisture content of the waste. A reasonable bed thickness and an adequate excessive air coefficient can keep a higher temperature, promote the burnout of combustibles, and consequently reduce the emission of dioxin pollutants. When the total air supply is constant, reducing primary air and introducing secondary air properly can enhance turbulence and mixing, prolong the residence time of flue gas, and promote the complete combustion of combustibles. This study provides an important reference for optimizing the design and operation of municipal solid wastes furnace.

  1. Configuration Consideration for Expander in Transcritical Carbon Dioxide Two-Stage Compression Cycle

    Institute of Scientific and Technical Information of China (English)

    MA Yitai; YANG Junlan; GUAN Haiqing; LI Minxia

    2005-01-01

    To investigate the configuration consideration of expander in transcritical carbon dioxide two-stage compression cycle, the best place in the cycle should be searched for to reinvest the recovery work so as to improve the system efficiency. The expander and the compressor are connected to the same shaft and integrated into one unit, with the latter being driven by the former, thus the transfer loss and leakage loss can be decreased greatly. In these systems, the expander can be either connected with the first stage compressor (shortened as DCDL cycle) or the second stage compressor (shortened as DCDH cycle), but the two configuration ways can get different performances. By setting up theoretical model for two kinds of expander configuration ways in the transcritical carbon dioxide two-stage compression cycle, the first and the second laws of thermodynamics are used to analyze the coefficient of performance, exergy efficiency, inter-stage pressure, discharge temperature and exergy losses of each component for the two cycles. From the model results, the performance of DCDH cycle is better than that of DCDL cycle. The analysis results are indispensable to providing a theoretical basis for practical design and operating.

  2. Two-stage coordination multi-radio multi-channel mac protocol for wireless mesh networks

    CERN Document Server

    Zhao, Bingxuan

    2011-01-01

    Within the wireless mesh network, a bottleneck problem arises as the number of concurrent traffic flows (NCTF) increases over a single common control channel, as it is for most conventional networks. To alleviate this problem, this paper proposes a two-stage coordination multi-radio multi-channel MAC (TSC-M2MAC) protocol that designates all available channels as both control channels and data channels in a time division manner through a two-stage coordination. At the first stage, a load balancing breadth-first-search-based vertex coloring algorithm for multi-radio conflict graph is proposed to intelligently allocate multiple control channels. At the second stage, a REQ/ACK/RES mechanism is proposed to realize dynamical channel allocation for data transmission. At this stage, the Channel-and-Radio Utilization Structure (CRUS) maintained by each node is able to alleviate the hidden nodes problem; also, the proposed adaptive adjustment algorithm for the Channel Negotiation and Allocation (CNA) sub-interval is ab...

  3. Design and optimisation of purification procedure for biodiesel washing

    Directory of Open Access Journals (Sweden)

    S.B. Glišić

    2009-09-01

    Full Text Available Almost complete methanolysis of triglycerides is usually not enough to fulfil the strict standards of biodiesel quality. A key step in this process is neutralization of alkali (catalyst followed by the washing procedure necessary for removing different impurities such as traces of catalyst and methanol and removal of soaps and glycerol from esters phase. The washing with hot water is still widely used in many industrial units for the biodiesel production. In this study, different procedures of biodiesel washing using hot water were investigated. The orto-phosphoric acid was suggested as the best compound for alkali catalyst (sodium hydroxide neutralization. The main goal of the performed analysis was to minimize the water usage in the washing-neutralization step during the biodiesel production. Such solution would make the process of biodiesel synthesis more economical taking into account the decrease of energy consumed for evaporation of water during the final product purification, as well as more acceptable procedure related to the impact on environment (minimal waste water release. Results of the performed simulation of the washing process supported by original experimental data suggested that neutralization after the optimized washing process of the methyl ester layer could be the best solution. The proposed washing procedure significantly decreases the amount of waste water giving at the same time the desired purity of final products (biodiesel and glycerol. The simulation of the process was performed using ASPEN plus software supported by ELCANTREL and UNIQUAC procedure of required properties calculation

  4. Improved Design of Crew Operation in Computerized Procedure System of APR1400

    Energy Technology Data Exchange (ETDEWEB)

    Seong, No Kyu; Jung, Yeon Sub; Sung, Chan Ho [KHNP, Daejeon (Korea, Republic of)

    2016-05-15

    The operators perform the paper-based procedures in analog-based conventional main control room (MCR) depending on only communications between operators except a procedure controller such as a Shift Supervisor (SS), however in digital-based MCR the operators can confirm the procedures simultaneously in own console when the procedure controller of computerized procedure (CP) opens the CP. The synchronization and a synchronization function between procedure controller and other operators has to be considered to support the function of crew operation. This paper suggests the improved design of crew operation in computerized procedure system of APR1400. This paper suggests the improved design of APR1400 CPS. These improvements can help operators perform the crew procedures more efficiently. And they reduce a burden of communication and misunderstanding of computerized procedures. These improvements can be applied to CPS after human factors engineering verification and validation.

  5. 47 CFR 68.418 - Procedure; designation of agents for service.

    Science.gov (United States)

    2010-10-01

    ... SERVICES (CONTINUED) CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK Complaint Procedures § 68... name or department designation, business address, telephone number, and, if available, TTY...

  6. Two Stage Battery System for the ROSETTA Lander

    Science.gov (United States)

    Debus, André

    2002-01-01

    The ROSETTA mission, lead by ESA, will be launched by Ariane V from Kourou in January 2003 and after a long trip, the spacecraft will reach the comet Wirtanen 46P in 2011. The mission includes a lander, built under the leadership of DLR, on which CNES has a large participation and is concerned by providing a part of the payload and some lander systems. Among these, CNES delivers a specific battery system in order to comply with the mission environment and the mission scenario, avoiding particularly the use of radio-isotopic heaters and radio-isotopic electrical generators usually used for such missions far from the Sun. The battery system includes : - a pack of primary batteries of lithium/thionyl chloride cells, this kind of generator - a secondary stage, including rechargeable lithium-ion cells, used as redundancy for the - a specific electronic system dedicated to the battery handling and to secondary battery - a mechanical and thermal (insulation, and heating devices) structures permitting the The complete battery system has been designed, built and qualified in order to comply with the trip and mission requirements, keeping within low mass and low volume limits. This battery system is presently integrated into the Rosetta Lander flight model and will leave the Earth at the beginning of next year. Such a development and experience could be re-used in the frame of cometary and planetary missions.

  7. An optimization-based design procedure for asymmetric bidirectional associative memories.

    Science.gov (United States)

    Park, J; Kwon, C H; Park, D

    2001-01-01

    In this letter, we consider the problem of designing asymmetric bidirectional associative memories (ABAM). Based on a newly derived theorem for the ABAM model, we propose an optimization-based design procedure for obtaining an ABAM that can store given bipolar vector pairs with certain error correction properties. Our design procedure consists of generalized eigenvalue problems, which can be efficiently solved by recently developed interior point methods. The validity of the proposed method is illustrated by a design example.

  8. Implementation of the AASHTO pavement design procedures into MULTI-PAVE.

    OpenAIRE

    Bekele, Abiy

    2011-01-01

    This thesis implements the empirical pavement design procedures for flexible as well as rigid pavement by American Association of State Highways and Transportation Officials (AASHTO) into two MATLAB modules of MULTI-PAVE. MULTI-PAVE was developed as a teaching tool that performs pavement thickness design for multiple design procedures using a common input file and a common output format. The AASHTO components were developed in accordance with the 1993 AASHTO Pavement Design Guide, and verifie...

  9. Experimental and modeling study of a two-stage pilot scale high solid anaerobic digester system.

    Science.gov (United States)

    Yu, Liang; Zhao, Quanbao; Ma, Jingwei; Frear, Craig; Chen, Shulin

    2012-11-01

    This study established a comprehensive model to configure a new two-stage high solid anaerobic digester (HSAD) system designed for highly degradable organic fraction of municipal solid wastes (OFMSW). The HSAD reactor as the first stage was naturally separated into two zones due to biogas floatation and low specific gravity of solid waste. The solid waste was retained in the upper zone while only the liquid leachate resided in the lower zone of the HSAD reactor. Continuous stirred-tank reactor (CSTR) and advective-diffusive reactor (ADR) models were constructed in series to describe the whole system. Anaerobic digestion model No. 1 (ADM1) was used as reaction kinetics and incorporated into each reactor module. Compared with the experimental data, the simulation results indicated that the model was able to well predict the pH, volatile fatty acid (VFA) and biogas production.

  10. Study of a two-stage photobase generator for photolithography in microelectronics.

    Science.gov (United States)

    Turro, Nicholas J; Li, Yongjun; Jockusch, Steffen; Hagiwara, Yuji; Okazaki, Masahiro; Mesch, Ryan A; Schuster, David I; Willson, C Grant

    2013-03-01

    The investigation of the photochemistry of a two-stage photobase generator (PBG) is described. Absorption of a photon by a latent PBG (1) (first step) produces a PBG (2). Irradiation of 2 in the presence of water produces a base (second step). This two-photon sequence (1 + hν → 2 + hν → base) is an important component in the design of photoresists for pitch division technology, a method that doubles the resolution of projection photolithography for the production of microelectronic chips. In the present system, the excitation of 1 results in a Norrish type II intramolecular hydrogen abstraction to generate a 1,4-biradiacal that undergoes cleavage to form 2 and acetophenone (Φ ∼ 0.04). In the second step, excitation of 2 causes cleavage of the oxime ester (Φ = 0.56) followed by base generation after reaction with water.

  11. STOCHASTIC DISCRETE MODEL OF TWO-STAGE ISOLATION SYSTEM WITH RIGID LIMITERS

    Institute of Scientific and Technical Information of China (English)

    HE Hua; FENG Qi; SHEN Rong-ying; WANG Yu

    2006-01-01

    The possible intermittent impacts of a two-stage isolation system with rigid limiters have been investigated. The isolation system is under periodic external excitation disturbed by small stationary Gaussian white noise after shock. The maximal impact Then in the period after shock, the zero order approximate stochastic discrete model and the first order approximate stochastic model are developed. The real isolation system of an MTU diesel engine is used to evaluate the established model. After calculating of the numerical example, the effects of noise excitation on the isolation system are discussed.The results show that the property of the system is complicated due to intermittent impact. The difference between zero order model and the first order model may be great.The effect of small noise is obvious. The results may be expected useful to the naval designers.

  12. Two-Stage Approach for Protein Superfamily Classification

    Directory of Open Access Journals (Sweden)

    Swati Vipsita

    2013-01-01

    Full Text Available We deal with the problem of protein superfamily classification in which the family membership of newly discovered amino acid sequence is predicted. Correct prediction is a matter of great concern for the researchers and drug analyst which helps them in discovery of new drugs. As this problem falls broadly under the category of pattern classification problem, we have made all efforts to optimize feature extraction in the first stage and classifier design in the second stage with an overall objective to maximize the performance accuracy of the classifier. In the feature extraction phase, Genetic Algorithm- (GA- based wrapper approach is used to select few eigenvectors from the principal component analysis (PCA space which are encoded as binary strings in the chromosome. On the basis of position of 1’s in the chromosome, the eigenvectors are selected to build the transformation matrix which then maps the original high-dimension feature space to lower dimension feature space. Using PCA-NSGA-II (non-dominated sorting GA, the nondominated solutions obtained from the Pareto front solve the trade-off problem by compromising between the number of eigenvectors selected and the accuracy obtained by the classifier. In the second stage, recursive orthogonal least square algorithm (ROLSA is used for training radial basis function network (RBFN to select optimal number of hidden centres as well as update the output layer weighting matrix. This approach can be applied to large data set with much lower requirements of computer memory. Thus, very small architectures having few number of hidden centres are obtained showing higher level of performance accuracy.

  13. HATS: A Design Procedure for Routine Business Documents.

    Science.gov (United States)

    Baker, William H.

    2001-01-01

    Describes an approach to teaching students a basic design process for routine business documents like memos, letters, and reports. Outlines the design principles of HATS (Headings, Access, Typography, and Spacing), how they apply in before-and-after fashion to various documents, and discusses an assignment in which students redesign an existing…

  14. The Production of High Purity Phycocyanin by Spirulina platensis Using Light-Emitting Diodes Based Two-Stage Cultivation.

    Science.gov (United States)

    Lee, Sang-Hyo; Lee, Ju Eun; Kim, Yoori; Lee, Seung-Yop

    2016-01-01

    Phycocyanin is a photosynthetic pigment found in photosynthetic cyanobacteria, cryptophytes, and red algae. In general, production of phycocyanin depends mainly on the light conditions during the cultivation period, and purification of phycocyanin requires expensive and complex procedures. In this study, we propose a new two-stage cultivation method to maximize the quantitative content and purity of phycocyanin obtained from Spirulina platensis using red and blue light-emitting diodes (LEDs) under different light intensities. In the first stage, Spirulina was cultured under a combination of red and blue LEDs to obtain the fast growth rate until reaching an absorbance of 1.4-1.6 at 680 nm. Next, blue LEDs were used to enhance the concentration and purity of the phycocyanin in Spirulina. Two weeks of the two-stage cultivation of Spirulina yielded 1.28 mg mL(-1) phycocyanin with the purity of 2.7 (OD620/OD280).

  15. An unit cost adjusting heuristic algorithm for the integrated planning and scheduling of a two-stage supply chain

    Directory of Open Access Journals (Sweden)

    Jianhua Wang

    2014-10-01

    Full Text Available Purpose: The stable relationship of one-supplier-one-customer is replaced by a dynamic relationship of multi-supplier-multi-customer in current market gradually, and efficient scheduling techniques are important tools of the dynamic supply chain relationship establishing process. This paper studies the optimization of the integrated planning and scheduling problem of a two-stage supply chain with multiple manufacturers and multiple retailers to obtain a minimum supply chain operating cost, whose manufacturers have different production capacities, holding and producing cost rates, transportation costs to retailers.Design/methodology/approach: As a complex task allocation and scheduling problem, this paper sets up an INLP model for it and designs a Unit Cost Adjusting (UCA heuristic algorithm that adjust the suppliers’ supplying quantity according to their unit costs step by step to solve the model.Findings: Relying on the contrasting analysis between the UCA and the Lingo solvers for optimizing many numerical experiments, results show that the INLP model and the UCA algorithm can obtain its near optimal solution of the two-stage supply chain’s planning and scheduling problem within very short CPU time.Research limitations/implications: The proposed UCA heuristic can easily help managers to optimizing the two-stage supply chain scheduling problems which doesn’t include the delivery time and batch of orders. For two-stage supply chains are the most common form of actual commercial relationships, so to make some modification and study on the UCA heuristic should be able to optimize the integrated planning and scheduling problems of a supply chain with more reality constraints.Originality/value: This research proposes an innovative UCA heuristic for optimizing the integrated planning and scheduling problem of two-stage supply chains with the constraints of suppliers’ production capacity and the orders’ delivering time, and has a great

  16. 23 CFR 636.202 - When are two-phase design-build selection procedures appropriate?

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false When are two-phase design-build selection procedures appropriate? 636.202 Section 636.202 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS DESIGN-BUILD CONTRACTING Selection Procedures, Award Criteria §...

  17. Anthropometric Procedures for Protective Equipment Sizing and Design

    Science.gov (United States)

    Hsiao, Hongwei

    2015-01-01

    Objectives This article presented four anthropometric theories (univariate, bivariate/probability distribution, multivariate, and shape-based methods) for protective equipment design decisions. Background While the significance of anthropometric information for product design is well recognized, designers continue to face challenges in selecting efficient anthropometric data processing methods and translating the acquired information into effective product designs. Methods For this study, 100 farm tractor operators, 3,718 respirator users, 951 firefighters, and 816 civilian workers participated in four studies on the design of tractor roll-over protective structures (ROPS), respirator test panels, fire truck cabs, and fall-arrest harnesses, respectively. Their anthropometry and participant-equipment interfaces were evaluated. Results Study 1 showed a need to extend the 90-cm vertical clearance for tractor ROPS in the current industrial standards to 98.3 to 101.3 cm. Study 2 indicated that current respirator test panel would have excluded 10% of the male firefighter population; a systematic adjustment to the boundaries of test panel cells was suggested. Study 3 provided 24 principal component analysis-based firefighter body models to facilitate fire truck cab design. Study 4 developed an improved gender-based fall-arrest harness sizing scheme to supplant the current unisex system. Conclusions This article presented four anthropometric approaches and a six-step design paradigm for ROPS, respirator test panel, fire truck cab, and fall-arrest harness applications, which demonstrated anthropometric theories and practices for defining protective equipment fit and sizing schemes. Applications The study provided a basis for equipment designers, standards writers, and industry manufacturers to advance anthropometric applications for product design and improve product efficacy. PMID:23516791

  18. Procedural guide for the design of transit stations and terminals

    Energy Technology Data Exchange (ETDEWEB)

    Demetsky, M.J.; Hoel, L.A.; Virkler, M.R.

    1977-06-01

    State-of-the-art concepts regarding the planning, design, and evaluation of passenger transportation stations are discussed. The material directs transportation planning teams to search for efficient station designs. The important stages and considerations in a comprehensive terminal analysis methodology are described. The transit station design process requires contributions from many disciplines and skills. The report given will help coordinate station development programs in accommodating inputs from the disciplines, and it highlights the elements of different stations to assure valid comparisons relative to performance and cost criteria.

  19. Design procedure for ritchey-chrétien corrector.

    Science.gov (United States)

    Howell, B J

    1969-03-01

    A four-lens corrector system to remove residual aberrations in a Ritchey-Chrétien telescope was selected as the means of studying the relative effectiveness of two design methods: a ray deviation error function and third order aberration theory. At several stages in the design, very significant improvements were made by switching from ray deviation results to aberration theory and then back to ray deviation design. The goal, a 300-cm focal length, f/10 diffraction-limited 1.2 degrees flat field telescope for white light, was achieved. Lens data and system performance, including computed spot diagrams, are given for eight versions.

  20. A gas-loading system for LANL two-stage gas guns

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, Lloyd Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bartram, Brian Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dattelbaum, Dana Mcgraw [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lang, John Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morris, John Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-01

    A novel gas loading system was designed for the specific application of remotely loading high purity gases into targets for gas-gun driven plate impact experiments. The high purity gases are loaded into well-defined target configurations to obtain Hugoniot states in the gas phase at greater than ambient pressures.The small volume of the gas samples is challenging, as slight changing in the ambient temperature result in measurable pressure changes. Therefore, the ability to load a gas gun target and continually monitor the sample pressure prior to firing provides the most stable and reliable target fielding approach. We present the design and evaluation of a gas loading system built for the LANL 50 mm bore two-stage light gas gun. Targets for the gun are made of 6061 Al or OFHC Cu, and assembled to form a gas containment cell with a volume of approximately 1.38 cc. The compatibility of materials was a major consideration in the design of the system, particularly for its use with corrosive gases. Piping and valves are stainless steel with wetted seals made from Kalrez® and Teflon®. Preliminary testing was completed to ensure proper flow rate and that the proper safety controls were in place. The system has been used to successfully load Ar, Kr, Xe, and anhydrous ammonia with purities of up to 99.999 percent. The design of the system and example data from the plate impact experiments will be shown.

  1. A gas-loading system for LANL two-stage gas guns

    Science.gov (United States)

    Gibson, L. L.; Bartram, B. D.; Dattelbaum, D. M.; Lang, J. M.; Morris, J. S.

    2017-01-01

    A novel gas loading system was designed for the specific application of remotely loading high purity gases into targets for gas-gun driven plate impact experiments. The high purity gases are loaded into well-defined target configurations to obtain Hugoniot states in the gas phase at greater than ambient pressures. The small volume of the gas samples is challenging, as slight changing in the ambient temperature result in measurable pressure changes. Therefore, the ability to load a gas gun target and continually monitor the sample pressure prior to firing provides the most stable and reliable target fielding approach. We present the design and evaluation of a gas loading system built for the LANL 50 mm bore two-stage light gas gun. Targets for the gun are made of 6061 Al or OFHC Cu, and assembled to form a gas containment cell with a volume of approximately 1.38 cc. The compatibility of materials was a major consideration in the design of the system, particularly for its use with corrosive gases. Piping and valves are stainless steel with wetted seals made from Kalrez® and Teflon®. Preliminary testing was completed to ensure proper flow rate and that the proper safety controls were in place. The system has been used to successfully load Ar, Kr, Xe, and anhydrous ammonia with purities of up to 99.999 percent. The design of the system and example data from the plate impact experiments will be shown.

  2. Anti-kindling Induced by Two-Stage Coordinated Reset Stimulation with Weak Onset Intensity

    Science.gov (United States)

    Zeitler, Magteld; Tass, Peter A.

    2016-01-01

    Abnormal neuronal synchrony plays an important role in a number of brain diseases. To specifically counteract abnormal neuronal synchrony by desynchronization, Coordinated Reset (CR) stimulation, a spatiotemporally patterned stimulation technique, was designed with computational means. In neuronal networks with spike timing–dependent plasticity CR stimulation causes a decrease of synaptic weights and finally anti-kindling, i.e., unlearning of abnormally strong synaptic connectivity and abnormal neuronal synchrony. Long-lasting desynchronizing aftereffects of CR stimulation have been verified in pre-clinical and clinical proof of concept studies. In general, for different neuromodulation approaches, both invasive and non-invasive, it is desirable to enable effective stimulation at reduced stimulation intensities, thereby avoiding side effects. For the first time, we here present a two-stage CR stimulation protocol, where two qualitatively different types of CR stimulation are delivered one after another, and the first stage comes at a particularly weak stimulation intensity. Numerical simulations show that a two-stage CR stimulation can induce the same degree of anti-kindling as a single-stage CR stimulation with intermediate stimulation intensity. This stimulation approach might be clinically beneficial in patients suffering from brain diseases characterized by abnormal neuronal synchrony where a first treatment stage should be performed at particularly weak stimulation intensities in order to avoid side effects. This might, e.g., be relevant in the context of acoustic CR stimulation in tinnitus patients with hyperacusis or in the case of electrical deep brain CR stimulation with sub-optimally positioned leads or side effects caused by stimulation of the target itself. We discuss how to apply our method in first in man and proof of concept studies. PMID:27242500

  3. Novel two-stage piezoelectric-based ocean wave energy harvesters for moored or unmoored buoys

    Science.gov (United States)

    Murray, R.; Rastegar, J.

    2009-03-01

    Harvesting mechanical energy from ocean wave oscillations for conversion to electrical energy has long been pursued as an alternative or self-contained power source. The attraction to harvesting energy from ocean waves stems from the sheer power of the wave motion, which can easily exceed 50 kW per meter of wave front. The principal barrier to harvesting this power is the very low and varying frequency of ocean waves, which generally vary from 0.1Hz to 0.5Hz. In this paper the application of a novel class of two-stage electrical energy generators to buoyant structures is presented. The generators use the buoy's interaction with the ocean waves as a low-speed input to a primary system, which, in turn, successively excites an array of vibratory elements (secondary system) into resonance - like a musician strumming a guitar. The key advantage of the present system is that by having two decoupled systems, the low frequency and highly varying buoy motion is converted into constant and much higher frequency mechanical vibrations. Electrical energy may then be harvested from the vibrating elements of the secondary system with high efficiency using piezoelectric elements. The operating principles of the novel two-stage technique are presented, including analytical formulations describing the transfer of energy between the two systems. Also, prototypical design examples are offered, as well as an in-depth computer simulation of a prototypical heaving-based wave energy harvester which generates electrical energy from the up-and-down motion of a buoy riding on the ocean's surface.

  4. Anti-kindling induced by two-stage coordinated reset stimulation with weak onset intensity

    Directory of Open Access Journals (Sweden)

    Magteld eZeitler

    2016-05-01

    Full Text Available Abnormal neuronal synchrony plays an important role in a number of brain diseases. To specifically counteract abnormal neuronal synchrony by desynchronization, Coordinated Reset (CR stimulation, a spatiotemporally patterned stimulation technique, was designed with computational means. In neuronal networks with spike timing–dependent plasticity CR stimulation causes a decrease of synaptic weights and finally anti-kindling, i.e. unlearning of abnormally strong synaptic connectivity and abnormal neuronal synchrony. Long-lasting desynchronizing aftereffects of CR stimulation have been verified in pre-clinical and clinical proof of concept studies. In general, for different neuromodulation approaches, both invasive and non-invasive, it is desirable to enable effective stimulation at reduced stimulation intensities, thereby avoiding side effects. For the first time, we here present a two-stage CR stimulation protocol, where two qualitatively different types of CR stimulation are delivered one after another, and the first stage comes at a particularly weak stimulation intensity. Numerical simulations show that a two-stage CR stimulation can induce the same degree of anti-kindling as a single-stage CR stimulation with intermediate stimulation intensity. This stimulation approach might be clinically beneficial in patients suffering from brain diseases characterized by abnormal neuronal synchrony where a first treatment stage should be performed at particularly weak stimulation intensities in order to avoid side effects. This might, e.g., be relevant in the context of acoustic CR stimulation in tinnitus patients with hyperacusis or in the case of electrical deep brain CR stimulation with sub-optimally positioned leads or side effects caused by stimulation of the target itself. We discuss how to apply our method in first in man and proof of concept studies.

  5. 40 CFR 240.203-2 - Recommended procedures: Design.

    Science.gov (United States)

    2010-07-01

    ..., easy to maintain, and consistent with the land use of the area. (d) Employee convenience facilities and... operating unit malfunctions. (j) Sampling capability should be designed into the facility so that each process stream can be sampled, and the utilities required to do so should be close at hand. The sampling...

  6. The Elaboration Theory's Procedure for Designing Instruction: A Conceptual Approach.

    Science.gov (United States)

    Reigeluth, Charles M.; Darwazeh, Afnan

    1982-01-01

    Describes the use of elaboration theory in selecting, sequencing, synthesizing, and summarizing instructional content that is predominantly conceptual in nature. The elaboration theory is summarized and the instructional design process based upon it is outlined. Six figures, a glossary, and a 27-item reference list are included. (Author/JL)

  7. Students' Design of a Biometric Procedure in Upper Secondary School

    Science.gov (United States)

    Marzin, Patricia; de Vries, Erica

    2013-01-01

    Making the connection between science and technology might be important for students to learn to identify and solve problems and to acquire scientific knowledge and skills. The research reported in this article concerned the development of a design situation in a science classroom and the study of students performing in this situation. More…

  8. User centered design of a digital procedure guidance component for nuclear power plant operation

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Paulo V.R. de; Santos, Isaac L. dos; Oliveira, Mauro V. de; Grecco, Claudio H.S.; Mol, Antonio C. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mails: paulov@ien.gov.br; luquetti@ien.gov.br; mvitor@ien.gov.br; grecco@ien.gov.br; mol@ien.gov.br

    2007-07-01

    The use of nuclear power plants to produce electric energy is a safety-critical process where ultimate operational decisions still relies with the control room operators. Thus it is important to provide the best possible decision support through effective supervisory control interfaces. A user centered design approach, based on cognitive task analysis methods, was used to observe the operators training on the nuclear power plant simulator of the Human System Interface Laboratory (LABIHS). We noted deficiencies in the integration between the computerized interfaces and the hardcopy (paper) procedures. An new prototype of digital procedures - the digital procedure component guidance (PCG) - was designed in PowerPoint as an alternative to the current hardcopy procedure manuals. The design improves upon the graphical layout of system information and provides better integration of procedures, automation, and alarm systems. The design was validated by expert opinion and a scenario-based comparison. Future implementation and testing of the redesign is suggested for further validation. (author)

  9. Preemptive scheduling in a two-stage supply chain to minimize the makespan

    NARCIS (Netherlands)

    Pei, Jun; Fan, Wenjuan; Pardalos, Panos M.; Liu, Xinbao; Goldengorin, Boris; Yang, Shanlin

    2015-01-01

    This paper deals with the problem of preemptive scheduling in a two-stage supply chain framework. The supply chain environment contains two stages: production and transportation. In the production stage jobs are processed on a manufacturer's bounded serial batching machine, preemptions are allowed,

  10. Development of a seismic design procedure for metal building systems

    OpenAIRE

    2007-01-01

    Metal building systems are widely used in low-rise (1- or 2-story) building construction for economic reasons. Maximum cost efficiency is usually achieved through optimization of steel weight and the fabrication process by adopting web-tapered members and bolted end-plate connections. However, the cyclic behavior of this kind of system has not been investigated, and no specific seismic design guidelines are available in the United States. Based on both experimental and analytical studies, thi...

  11. Remote liquid target loading system for LANL two-stage gas gun

    Science.gov (United States)

    Gibson, L. L.; Bartram, B.; Dattelbaum, D. M.; Sheffield, S. A.; Stahl, D. B.

    2009-06-01

    A Remote Liquid Loading System (RLLS) was designed to load high hazard liquid materials into targets for gas-gun driven impact experiments. These high hazard liquids tend to react with confining materials in a short period of time, degrading target assemblies and potentially building up pressure through the evolution of gas in the reactions. Therefore, the ability to load a gas gun target in place immediately prior to firing the gun, provides the most stable and reliable target fielding approach. We present the design and evaluation of a RLLS built for the LANL two-stage gas gun. Targets for the gun are made of PMMA and assembled to form a liquid containment cell with a volume of approximately 25 cc. The compatibility of materials was a major consideration in the design of the system, particularly for its use with highly concentrated hydrogen peroxide. Teflon and 304-stainless steel were the two most compatible materials with the materials to be tested. Teflon valves and tubing, as well as stainless steel tubing, were used to handle the liquid, along with a stainless steel reservoir. Preliminary testing was done to ensure proper flow rate and safety. The system has been used to successfully load 97.5 percent hydrogen peroxide into a target cell just prior to a successful multiple magnetic gauge experiment. TV cameras on the target verified the bubble-free filling operation.

  12. An annotated summary of the Information Model Design Procedure (IMDP)

    Energy Technology Data Exchange (ETDEWEB)

    Becker, S.D.

    1994-05-01

    This presentation documents the essential elements of the IMDP as applied at Sandia National Laboratories/New Mexico. The IMDP is an adaptation of the Natural-Language Information Analysis Methodology (NIAM) of G. M. Nijssen. The underlying purpose of both of these methodologies is to provide a formal, reproducible, and verifiable approach to specifying the information requirements of an information system. The IMDP spans the specification process from initial scoping; through verbalization of problem-domain facts, specification of constraints, and subtype analysis; and finally to application of a formal algorithm for developing a fifth-normal-form relational database design.

  13. Two-stage method for purification of ceruloplasmin based on its interaction with neomycin.

    Science.gov (United States)

    Sokolov, A V; Kostevich, V A; Romanico, D N; Zakharova, E T; Vasilyev, V B

    2012-06-01

    A two-stage chromatography that yields highly purified ceruloplasmin (CP) from human plasma and from rat and rabbit serum is described. The isolation procedure is based on the interaction of CP with neomycin, and it provides a high yield of CP. Constants of inhibition by gentamycin, kanamycin, and neomycin of oxidase activity of CP in its reaction with p-phenylenediamine were assayed. The lowest K(i) for neomycin (11 µM) corresponded to the highest specific adsorption of CP on neomycin-agarose (10 mg CP/ml of resin). Isolation of CP from 1.4 liters of human plasma using ion-exchange chromatography on UNO-Sphere Q and affinity chromatography on neomycin-agarose yields 348 mg of CP with 412-fold purification degree. Human CP preparation obtained with A(610)/A(280) ~ 0.052 contained neither immunoreactive prothrombin nor active thrombin. Upon storage at 37°C under sterile conditions, the preparation remained stable for two months. Efficient preparation of highly purified CP from rat and rabbit sera treated according to a similar protocol suggests the suitability of our method for isolation of CP from plasma and serum of other animals. The yield of CP in three separate purifications was no less than 78%.

  14. Artificial trachea reconstruction with two-stage approach using memory-alloy mesh

    Institute of Scientific and Technical Information of China (English)

    赵凤瑞; 张银合; 刘世民; 余建军

    2003-01-01

    @@ Artificial tracheal prosthesis is now a challenge to the entire surgical field all over the world. Previously, all kinds of prosthesis were "inner stent" that could not be integrated with native trachea. Since there is an interface between smooth surface of the prosthesis and living tissues, and the inner side of the prosthesis is not covered with living membrane, infections always happen around the prosthesis. We then developed a new technique, which combined memory-alloy mesh with traditional operative procedures. Memory-alloy mesh is extensible, flexible and can maintain the shape of a tube. It has very good compatibility with tissues and no antigenicity. Thus, it is the most desirable material nowadays that can be found to make the frame of an artificial trachea by using a two-stage approach. That is imbedding a pre-shaped memory-alloy mesh under skin or endothelium (pleura or peritoneum), and then making the "sandwich" pedicle skin and muscle flap to a pedicled artificial trachea anastomosed with native trachea. After a two-year experimental study, a patient received the artificial trachea replacement on April 18, 2002, with a good result.

  15. Inverse airfoil design procedure using a multigrid Navier-Stokes method

    Science.gov (United States)

    Malone, J. B.; Swanson, R. C.

    1991-01-01

    The Modified Garabedian McFadden (MGM) design procedure was incorporated into an existing 2-D multigrid Navier-Stokes airfoil analysis method. The resulting design method is an iterative procedure based on a residual correction algorithm and permits the automated design of airfoil sections with prescribed surface pressure distributions. The new design method, Multigrid Modified Garabedian McFadden (MG-MGM), is demonstrated for several different transonic pressure distributions obtained from both symmetric and cambered airfoil shapes. The airfoil profiles generated with the MG-MGM code are compared to the original configurations to assess the capabilities of the inverse design method.

  16. The Florey Adelaide Male Ageing Study (FAMAS: Design, procedures & participants

    Directory of Open Access Journals (Sweden)

    Middleton Sue M

    2007-06-01

    Full Text Available Abstract Background The Florey Adelaide Male Ageing Study (FAMAS examines the reproductive, physical and psychological health, and health service utilisation of the ageing male in Australia. We describe the rationale for the study, the methods used participant response rates, representativeness and attrition to date. Methods FAMAS is a longitudinal study involving approximately 1200 randomly selected men, aged 35–80 years and living in the north – west regions of Adelaide. Respondents were excluded at screening if they were considered incapable of participating because of immobility, language, or an inability to undertake the study procedures. Following a telephone call to randomly selected households, eligible participants were invited to attend a baseline clinic measuring a variety of biomedical and socio-demographic factors. Beginning in 2002, these clinics are scheduled to reoccur every five years. Follow-up questionnaires are completed annually. Participants are also invited to participate in sub-studies with selected collaborators. Results Of those eligible to participate, 45.1% ultimately attended a clinic. Non-responders were more likely to live alone, be current smokers, have a higheevalence of self-reported diabetes and stroke, and lower levels of hypercholesterolemia. Comparisons with the Census 2001 data showed that participants matched the population for most key demographics, although younger groups and never married men were under-represented and elderly participants were over-represented. To date, there has been an annual loss to follow-up of just over 1%. Conclusion FAMAS allows a detailed investigation into the effects of bio-psychosocial and behavioural factors on the health and ageing of a largely representative group of Australian men.

  17. Increasing spelling achievement: an analysis of treatment procedures utilizing an alternating treatments design.

    OpenAIRE

    Ollendick, T. H.; Matson, J L; Esveldt-Dawson, K; Shapiro, E S

    1980-01-01

    Two studies which examine the effectiveness of spelling remediation procedures are reported. In both studies, an alternating treatment design was employed. In the first study, positive practice overcorrection plus positive reinforcement was compared to positive practice alone and a no-remediation control condition. In the second study, positive practice plus positive reinforcement was compared to a traditional corrective procedure plus positive reinforcement and a traditional procedure when u...

  18. A Structural Design of Insulated and Heat Conduction Ceramic Plate Used in Two Stage Depressed Collectors%一种应用于两级降压收集极的绝缘导热瓷件的结构设计

    Institute of Scientific and Technical Information of China (English)

    骆岷; 杨定义; 周明干

    2012-01-01

    A structural design of insulated and heat conduction ceramic plate,which think about material choice, insulated space and so on. And the design results used in practice.%介绍了一种绝缘导热瓷件的结构设计,从材料的选择、绝缘距离的考虑等方面进行了考虑,给出了设计结果及实际应用情况.

  19. Decentralized combined heat and power production by two-stage biomass gasification and solid oxide fuel cells

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud; Elmegaard, Brian

    2013-01-01

    To investigate options for increasing the electrical efficiency of decentralized combined heat and power (CHP) plants fuelled with biomass compared to conventional technology, this research explored the performance of an alternative plant design based on thermal biomass gasification and solid oxide...... fuel cells (SOFC). Based on experimental data from a demonstrated 0.6 MWth two-stage gasifier, a model of the gasifier plant was developed and calibrated. Similarly, an SOFC model was developed using published experimental data. Simulation of a 3 MWth plant combining two-stage biomass gasification......, carbon conversion factor in the gasifier and the efficiency of the DC/AC inverter were the most influential parameters in the model. Thus, a detailed study of the practical values of these parameters was conducted to determine the performance of the plant with the lowest possible uncertainty. The SOFC...

  20. A Two-Stage State Recognition Method for Asynchronous SSVEP-Based Brain-Computer Interface System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zimu; DENG Zhidong

    2013-01-01

    A two-stage state recognition method is proposed for asynchronous SSVEP (steady-state visual evoked potential) based brain-computer interface (SBCI) system.The two-stage method is composed of the idle state (IS) detection and control state (CS) discrimination modules.Based on blind source separation and continuous wavelet transform techniques,the proposed method integrates functions of multi-electrode spatial filtering and feature extraction.In IS detection module,a method using the ensemble IS feature is proposed.In CS discrimination module,the ensemble CS feature is designed as feature vector for control intent classification.Further,performance comparisons are investigated among our IS detection module and other existing ones.Also the experimental results validate the satisfactory performance of our CS discrimination module.

  1. Two stage hydrolysis of corn stover at high solids content for mixing power saving and scale-up applications.

    Science.gov (United States)

    Liu, Ke; Zhang, Jian; Bao, Jie

    2015-11-01

    A two stage hydrolysis of corn stover was designed to solve the difficulties between sufficient mixing at high solids content and high power input encountered in large scale bioreactors. The process starts with the quick liquefaction to convert solid cellulose to liquid slurry with strong mixing in small reactors, then followed the comprehensive hydrolysis to complete saccharification into fermentable sugars in large reactors without agitation apparatus. 60% of the mixing energy consumption was saved by removing the mixing apparatus in large scale vessels. Scale-up ratio was small for the first step hydrolysis reactors because of the reduced reactor volume. For large saccharification reactors in the second step, the scale-up was easy because of no mixing mechanism was involved. This two stage hydrolysis is applicable for either simple hydrolysis or combined fermentation processes. The method provided a practical process option for industrial scale biorefinery processing of lignocellulose biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. 6 CFR 25.6 - Procedures for designation of qualified anti-terrorism technologies.

    Science.gov (United States)

    2010-01-01

    ...-terrorism technologies. 25.6 Section 25.6 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY REGULATIONS TO SUPPORT ANTI-TERRORISM BY FOSTERING EFFECTIVE TECHNOLOGIES § 25.6 Procedures for designation of qualified anti-terrorism technologies. (a) Application Procedure. Any person, firm or other...

  3. A CURRENT MIRROR BASED TWO STAGE CMOS CASCODE OP-AMP FOR HIGH FREQUENCY APPLICATION

    Directory of Open Access Journals (Sweden)

    RAMKRISHNA KUNDU

    2017-03-01

    Full Text Available This paper presents a low power, high slew rate, high gain, ultra wide band two stage CMOS cascode operational amplifier for radio frequency application. Current mirror based cascoding technique and pole zero cancelation technique is used to ameliorate the gain and enhance the unity gain bandwidth respectively, which is the novelty of the circuit. In cascading technique a common source transistor drive a common gate transistor. The cascoding is used to enhance the output resistance and hence improve the overall gain of the operational amplifier with less complexity and less power dissipation. To bias the common gate transistor, a current mirror is used in this paper. The proposed circuit is designed and simulated using Cadence analog and digital system design tools of 45 nanometer CMOS technology. The simulated results of the circuit show DC gain of 63.62 dB, unity gain bandwidth of 2.70 GHz, slew rate of 1816 V/µs, phase margin of 59.53º, power supply of the proposed operational amplifier is 1.4 V (rail-to-rail ±700 mV, and power consumption is 0.71 mW. This circuit specification has encountered the requirements of radio frequency application.

  4. A two-stage storage routing model for green roof runoff detention.

    Science.gov (United States)

    Vesuviano, Gianni; Sonnenwald, Fred; Stovin, Virginia

    2014-01-01

    Green roofs have been adopted in urban drainage systems to control the total quantity and volumetric flow rate of runoff. Modern green roof designs are multi-layered, their main components being vegetation, substrate and, in almost all cases, a separate drainage layer. Most current hydrological models of green roofs combine the modelling of the separate layers into a single process; these models have limited predictive capability for roofs not sharing the same design. An adaptable, generic, two-stage model for a system consisting of a granular substrate over a hard plastic 'egg box'-style drainage layer and fibrous protection mat is presented. The substrate and drainage layer/protection mat are modelled separately by previously verified sub-models. Controlled storm events are applied to a green roof system in a rainfall simulator. The time-series modelled runoff is compared to the monitored runoff for each storm event. The modelled runoff profiles are accurate (mean Rt(2) = 0.971), but further characterization of the substrate component is required for the model to be generically applicable to other roof configurations with different substrate.

  5. Multifunctional Solar Systems Based On Two-Stage Regeneration Absorbent Solution

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2015-04-01

    Full Text Available The concepts of multifunctional dehumidification solar systems, heat supply, cooling, and air conditioning based on the open absorption cycle with direct absorbent regeneration developed. The solar systems based on preliminary drainage of current of air and subsequent evaporated cooling. The solar system using evaporative coolers both types (direct and indirect. The principle of two-stage regeneration of absorbent used in the solar systems, it used as the basis of liquid and gas-liquid solar collectors. The main principle solutions are designed for the new generation of gas-liquid solar collectors. Analysis of the heat losses in the gas-liquid solar collectors, due to the mechanism of convection and radiation is made. Optimal cost of gas and liquid, as well as the basic dimensions and configuration of the working channel of the solar collector identified. Heat and mass transfer devices, belonging to the evaporative cooling system based on the interaction between the film and the gas stream and the liquid therein. Multichannel structure of the polymeric materials used to create the tip. Evaporative coolers of water and air both types (direct and indirect are used in the cooling of the solar systems. Preliminary analysis of the possibilities of multifunctional solar absorption systems made reference to problems of cooling media and air conditioning on the basis of experimental data the authors. Designed solar systems feature low power consumption and environmental friendliness.

  6. A Risk-Based Interval Two-Stage Programming Model for Agricultural System Management under Uncertainty

    Directory of Open Access Journals (Sweden)

    Ye Xu

    2016-01-01

    Full Text Available Nonpoint source (NPS pollution caused by agricultural activities is main reason that water quality in watershed becomes worse, even leading to deterioration. Moreover, pollution control is accompanied with revenue’s fall for agricultural system. How to design and generate a cost-effective and environmentally friendly agricultural production pattern is a critical issue for local managers. In this study, a risk-based interval two-stage programming model (RBITSP was developed. Compared to general ITSP model, significant contribution made by RBITSP model was that it emphasized importance of financial risk under various probabilistic levels, rather than only being concentrated on expected economic benefit, where risk is expressed as the probability of not meeting target profit under each individual scenario realization. This way effectively avoided solutions’ inaccuracy caused by traditional expected objective function and generated a variety of solutions through adjusting weight coefficients, which reflected trade-off between system economy and reliability. A case study of agricultural production management with the Tai Lake watershed was used to demonstrate superiority of proposed model. Obtained results could be a base for designing land-structure adjustment patterns and farmland retirement schemes and realizing balance of system benefit, system-failure risk, and water-body protection.

  7. Two-stage seasonal streamflow forecasts to guide water resources decisions and water rights allocation

    Science.gov (United States)

    Block, P. J.; Gonzalez, E.; Bonnafous, L.

    2011-12-01

    Decision-making in water resources is inherently uncertain producing copious risks, ranging from operational (present) to planning (season-ahead) to design/adaptation (decadal) time-scales. These risks include human activity and climate variability/change. As the risks in designing and operating water systems and allocating available supplies vary systematically in time, prospects for predicting and managing such risks become increasingly attractive. Considerable effort has been undertaken to improve seasonal forecast skill and advocate for integration to reduce risk, however only minimal adoption is evident. Impediments are well defined, yet tailoring forecast products and allowing for flexible adoption assist in overcoming some obstacles. The semi-arid Elqui River basin in Chile is contending with increasing levels of water stress and demand coupled with insufficient investment in infrastructure, taxing its ability to meet agriculture, hydropower, and environmental requirements. The basin is fed from a retreating glacier, with allocation principles founded on a system of water rights and markets. A two-stage seasonal streamflow forecast at leads of one and two seasons prescribes the probability of reductions in the value of each water right, allowing water managers to inform their constituents in advance. A tool linking the streamflow forecast to a simple reservoir decision model also allows water managers to select a level of confidence in the forecast information.

  8. Two-staged nuclear transfer can enhance the developmental ability of goat-sheep interspecies nuclear transfer embryos in vitro.

    Science.gov (United States)

    Ma, Li-Bing; Cai, Lu; Li, Jia-Jia; Chen, Xiu-Li; Ji, Feng-Yu

    2011-02-01

    The technique of interspecies somatic cell nuclear transfer, in which interspecies cloned embryos can be reconstructed by using domestic animal oocytes as nuclear recipients and endangered animal or human somatic cells as nuclear donors, can afford more opportunities in endangered animal rescue and human tissue transplantation, but the application of this technique is limited by extremely low efficiency which may be attributed to donor nucleus not fully reprogrammed by xenogenic cytoplasm. In this study, goat fetal fibroblasts (GFFs) were used as nuclear donors, in vitro-matured sheep oocytes were used as nuclear recipients, and a two-stage nuclear transfer procedure was performed to improve the developmental ability of goat-sheep interspecies clone embryos. In the first stage nuclear transfer (FSNT), GFFs were injected into the ooplasm of enucleated sheep metaphase-II oocytes, then non-activated reconstructed embryos were cultured in vitro, so that the donor nucleus could be exposed to the ooplasm for a period of time. Subsequently, in the second stage nuclear transfer, FSNT-derived non-activated reconstructed embryo was centrifuged, and the donor nucleus was then transferred into another freshly enucleated sheep oocyte. Compared with the one-stage nuclear transfer, two-stage nuclear transfer could significantly enhance the blastocyst rate of goat-sheep interspecies clone embryos, and this result indicated that longtime exposure to xenogenic ooplasm benefits the donor nucleus to be reprogrammed. The two-stage nuclear transfer procedure has two advantages, one is that the donor nucleus can be exposed to the ooplasm for a long time, the other is that the problem of oocyte aging can be solved.

  9. Thermodynamic analysis of small-scale dimethyl ether (DME) and methanol plants based on the efficient two-stage gasifier

    DEFF Research Database (Denmark)

    Clausen, Lasse Røngaard; Elmegaard, Brian; Ahrenfeldt, Jesper

    2011-01-01

    Models of dimethyl ether (DME) and methanol synthesis plants have been designed by combining the features of the simulation tools DNA and Aspen Plus. The plants produce DME or methanol by catalytic conversion of a syngas generated by gasification of woody biomass. Electricity is co......-produced in the plants by a gas engine utilizing the unconverted syngas. A two-stage gasifier with a cold gas efficiency of 93% is used, but because of the design of this type of gasifier, the plants have to be of small-scale (5 MWth biomass input). The plant models show energy efficiencies from biomass to DME/methanol...

  10. Numerical simulation of a step-piston type series two-stage pulse tube refrigerator

    Science.gov (United States)

    Zhu, Shaowei; Nogawa, Masafumi; Inoue, Tatsuo

    2007-09-01

    A two-stage pulse tube refrigerator has a great advantage in that there are no moving parts at low temperatures. The problem is low theoretical efficiency. In an ordinary two-stage pulse tube refrigerator, the expansion work of the first stage pulse tube is rather large, but is changed to heat. The theoretical efficiency is lower than that of a Stirling refrigerator. A series two-stage pulse tube refrigerator was introduced for solving this problem. The hot end of the regenerator of the second stage is connected to the hot end of the first stage pulse tube. The expansion work in the first stage pulse tube is part of the input work of the second stage, therefore the efficiency is increased. In a simulation result for a step-piston type two-stage series pulse tube refrigerator, the efficiency is increased by 13.8%.

  11. Theory and calculation of two-stage voltage stabilizer on zener diodes

    Directory of Open Access Journals (Sweden)

    G. S. Veksler

    1966-12-01

    Full Text Available Two-stage stabilizer is compared with one-stage. There have been got formulas, which give the possibility to make an engineering calculation. There is an example of the calculation.

  12. Two-stage fungal pre-treatment for improved biogas production from sisal leaf decortication residues

    National Research Council Canada - National Science Library

    Muthangya, Mutemi; Mshandete, Anthony Manoni; Kivaisi, Amelia Kajumulo

    2009-01-01

    .... Pre-treatment of the residue prior to its anaerobic digestion (AD) was investigated using a two-stage pre-treatment approach with two fungal strains, CCHT-1 and Trichoderma reesei in succession in anaerobic batch bioreactors...

  13. Experiment research on two-stage dry-fed entrained flow coal gasifier

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The process flow and the main devices of a new two-stage dry-fed coal gasification pilot plant with a throughout of 36 t/d are introduced in this paper. For comparison with the traditional one-stage gasifiers, the influences of the coal feed ratio between two stages on the performance of the gasifier are detailedly studied by a series of experiments. The results reveal that the two-stage gasification decreases the temperature of the syngas at the outlet of the gasifier, simplifies the gasification process, and reduces the size of the syngas cooler. Moreover, the cold gas efficiency of the gasifier can be improved by using the two-stage gasification. In our experiments, the efficiency is about 3%-6% higher than the existing one-stage gasifiers.

  14. TWO-STAGE CHARACTER CLASSIFICATION : A COMBINED APPROACH OF CLUSTERING AND SUPPORT VECTOR CLASSIFIERS

    NARCIS (Netherlands)

    Vuurpijl, L.; Schomaker, L.

    2000-01-01

    This paper describes a two-stage classification method for (1) classification of isolated characters and (2) verification of the classification result. Character prototypes are generated using hierarchical clustering. For those prototypes known to sometimes produce wrong classification results, a

  15. Controller tuning with evolutionary multiobjective optimization a holistic multiobjective optimization design procedure

    CERN Document Server

    Reynoso Meza, Gilberto; Sanchis Saez, Javier; Herrero Durá, Juan Manuel

    2017-01-01

    This book is devoted to Multiobjective Optimization Design (MOOD) procedures for controller tuning applications, by means of Evolutionary Multiobjective Optimization (EMO). It presents developments in tools, procedures and guidelines to facilitate this process, covering the three fundamental steps in the procedure: problem definition, optimization and decision-making. The book is divided into four parts. The first part, Fundamentals, focuses on the necessary theoretical background and provides specific tools for practitioners. The second part, Basics, examines a range of basic examples regarding the MOOD procedure for controller tuning, while the third part, Benchmarking, demonstrates how the MOOD procedure can be employed in several control engineering problems. The fourth part, Applications, is dedicated to implementing the MOOD procedure for controller tuning in real processes.

  16. Bayesian and frequentist two-stage treatment strategies based on sequential failure times subject to interval censoring.

    Science.gov (United States)

    Thall, Peter F; Wooten, Leiko H; Logothetis, Christopher J; Millikan, Randall E; Tannir, Nizar M

    2007-11-20

    For many diseases, therapy involves multiple stages, with the treatment in each stage chosen adaptively based on the patient's current disease status and history of previous treatments and clinical outcomes. Physicians routinely use such multi-stage treatment strategies, also called dynamic treatment regimes or treatment policies. We present a Bayesian framework for a clinical trial comparing two-stage strategies based on the time to overall failure, defined as either second disease worsening or discontinuation of therapy. Each patient is randomized among a set of treatments at enrollment, and if disease worsening occurs the patient is then re-randomized among a set of treatments excluding the treatment received initially. The goal is to select the two-stage strategy having the largest average overall failure time. A parametric model is formulated to account for non-constant failure time hazards, regression of the second failure time on the patient's first worsening time, and the complications that the failure time in either stage may be interval censored and there may be a delay between first worsening and the start of the second stage of therapy. Four different criteria, two Bayesian and two frequentist, for selecting a best strategy are considered. The methods are applied to a trial comparing two-stage strategies for treating metastatic renal cancer, and a simulation study in the context of this trial is presented. Advantages and disadvantages of this design compared to standard methods are discussed.

  17. A new multi-motor drive system based on two-stage direct power converter

    OpenAIRE

    Kumar, Dinesh

    2011-01-01

    The two-stage AC to AC direct power converter is an alternative matrix converter topology, which offers the benefits of sinusoidal input currents and output voltages, bidirectional power flow and controllable input power factor. The absence of any energy storage devices, such as electrolytic capacitors, has increased the potential lifetime of the converter. In this research work, a new multi-motor drive system based on a two-stage direct power converter has been proposed, with two motors c...

  18. Maximally efficient two-stage screening: Determining intellectual disability in Taiwanese military conscripts

    Directory of Open Access Journals (Sweden)

    Chia-Chang Chien

    2009-01-01

    Full Text Available Chia-Chang Chien1, Shu-Fen Huang1,2,3,4, For-Wey Lung1,2,3,41Department of Psychiatry, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan; 2Graduate Institute of Behavioral Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan; 3Department of Psychiatry, National Defense Medical Center, Taipei, Taiwan; 4Calo Psychiatric Center, Pingtung County, TaiwanObjective: The purpose of this study was to apply a two-stage screening method for the large-scale intelligence screening of military conscripts.Methods: We collected 99 conscripted soldiers whose educational levels were senior high school level or lower to be the participants. Every participant was required to take the Wisconsin Card Sorting Test (WCST and the Wechsler Adult Intelligence Scale-Revised (WAIS-R assessments.Results: Logistic regression analysis showed the conceptual level responses (CLR index of the WCST was the most significant index for determining intellectual disability (ID; FIQ ≤ 84. We used the receiver operating characteristic curve to determine the optimum cut-off point of CLR. The optimum one cut-off point of CLR was 66; the two cut-off points were 49 and 66. Comparing the two-stage window screening with the two-stage positive screening, the area under the curve and the positive predictive value increased. Moreover, the cost of the two-stage window screening decreased by 59%.Conclusion: The two-stage window screening is more accurate and economical than the two-stage positive screening. Our results provide an example for the use of two-stage screening and the possibility of the WCST to replace WAIS-R in large-scale screenings for ID in the future.Keywords: intellectual disability, intelligence screening, two-stage positive screening, Wisconsin Card Sorting Test, Wechsler Adult Intelligence Scale-Revised

  19. Two-Stage Conversion of Land and Marine Biomass for Biogas and Biohydrogen Production

    OpenAIRE

    Nkemka, Valentine

    2012-01-01

    The replacement of fossil fuels by renewable fuels such as biogas and biohydrogen will require efficient and economically competitive process technologies together with new kinds of biomass. A two-stage system for biogas production has several advantages over the widely used one-stage continuous stirred tank reactor (CSTR). However, it has not yet been widely implemented on a large scale. Biohydrogen can be produced in the anaerobic two-stage system. It is considered to be a useful fuel for t...

  20. Two-stage biofilter for effective NH3 removal from waste gases containing high concentrations of H2S.

    Science.gov (United States)

    Chung, Ying-Chien; Ho, Kuo-Ling; Tseng, Ching-Ping

    2007-03-01

    A high H2S concentration inhibits nitrification when H2S and NH3 are simultaneously treated in a single biofilter. To improve NH3 removal from waste gases containing concentrated H2S, a two-stage biofilter was designed to solve the problem. In this study, the first biofilter, inoculated with Thiobacillus thioparus, was intended mainly to remove H2S and to reduce the effect of H2S concentration on nitrification in the second biofilter, and the second biofilter, inoculated with Nitrosomonas europaea, was to remove NH3. Extensive studies, which took into account the characteristics of gas removal, the engineering properties of the two biofilters, and biological parameters, were conducted in a 210-day operation. The results showed that an average 98% removal efficiency for H2S and a 100% removal efficiency for NH3 (empty bed retention time = 23-180 sec) were achieved after 70 days. The maximum degradation rate for NH3 was measured as 2.35 g N day(-1) kg of dry granular activated carbon(-1). Inhibition of nitrification was not found in the biofilter. This two-stage biofilter also exhibited good adaptability to shock loading and shutdown periods. Analysis of metabolic product and observation of the bacterial community revealed no obvious acidification or alkalinity phenomena. In addition, a lower moisture content (approximately 40%) for microbial survival and low pressure drop (average 24.39 mm H2O m(-1)) for system operation demonstrated that the two-stage biofilter was energy saving and economic. Thus, the two-stage biofilter is a feasible system to enhance NH3 removal in the concentrated coexistence of H2S.

  1. A farm-scale pilot plant for biohydrogen and biomethane production by two-stage fermentation

    Directory of Open Access Journals (Sweden)

    R. Oberti

    2013-09-01

    Full Text Available Hydrogen is considered one of the possible main energy carriers for the future, thanks to its unique environmental properties. Indeed, its energy content (120 MJ/kg can be exploited virtually without emitting any exhaust in the atmosphere except for water. Renewable production of hydrogen can be obtained through common biological processes on which relies anaerobic digestion, a well-established technology in use at farm-scale for treating different biomass and residues. Despite two-stage hydrogen and methane producing fermentation is a simple variant of the traditional anaerobic digestion, it is a relatively new approach mainly studied at laboratory scale. It is based on biomass fermentation in two separate, seuqential stages, each maintaining conditions optimized to promote specific bacterial consortia: in the first acidophilic reactorhydrogen is produced production, while volatile fatty acids-rich effluent is sent to the second reactor where traditional methane rich biogas production is accomplished. A two-stage pilot-scale plant was designed, manufactured and installed at the experimental farm of the University of Milano and operated using a biomass mixture of livestock effluents mixed with sugar/starch-rich residues (rotten fruits and potatoes and expired fruit juices, afeedstock mixture based on waste biomasses directly available in the rural area where plant is installed. The hydrogenic and the methanogenic reactors, both CSTR type, had a total volume of 0.7m3 and 3.8 m3 respectively, and were operated in thermophilic conditions (55 2 °C without any external pH control, and were fully automated. After a brief description of the requirements of the system, this contribution gives a detailed description of its components and of engineering solutions to the problems encountered during the plant realization and start-up. The paper also discusses the results obtained in a first experimental run which lead to production in the range of previous

  2. Two-Stage Thoracoscopic Repair of Long-Gap Esophageal Atresia Using Internal Traction Is Safe and Feasible.

    Science.gov (United States)

    Tainaka, Takahisa; Uchida, Hiroo; Tanano, Akihide; Shirota, Chiyoe; Hinoki, Akinari; Murase, Naruhiko; Yokota, Kazuki; Oshima, Kazuo; Shirotsuki, Ryo; Chiba, Kosuke; Amano, Hizuru; Kawashima, Hiroshi; Tanaka, Yujiro

    2017-01-01

    The treatment of long-gap esophageal atresia remains an issue for pediatric surgeons. Many techniques for treating long-gap esophageal atresia have been proposed, but the optimal method has not been established. The thoracoscopic esophageal elongation technique has recently been developed. We previously reported a case in which two-stage thoracoscopic repair was performed using internal esophageal traction without esophageal tearing, and we retrospectively reviewed the outcomes of this procedure in this study. Five patients underwent thoracoscopic treatment involving internal esophageal traction for esophageal atresia involving a long gap or vascular ring over a 5-year period. Between November 2010 and November 2015, 5 patients were treated with thoracoscopic traction. All of these patients successfully underwent thoracoscopic-delayed primary anastomosis. Conversion to open thoracotomy was not required in any case. The postoperative complications experienced by the patients included minor anastomotic leakage in 2 cases, anastomotic stenosis in 1 case, gastroesophageal reflux (GER) in 4 cases, and a hiatal hernia in 1 case. None of the patients died. Two-stage thoracoscopic repair for esophageal atresia involving a long gap or vascular ring is a safe and feasible procedure; however, we must develop methods for treating minor anastomotic complications and GER due to esophageal traction in future.

  3. A Two-Stage Queue Model to Optimize Layout of Urban Drainage System considering Extreme Rainstorms

    Directory of Open Access Journals (Sweden)

    Xinhua He

    2017-01-01

    Full Text Available Extreme rainstorm is a main factor to cause urban floods when urban drainage system cannot discharge stormwater successfully. This paper investigates distribution feature of rainstorms and draining process of urban drainage systems and uses a two-stage single-counter queue method M/M/1→M/D/1 to model urban drainage system. The model emphasizes randomness of extreme rainstorms, fuzziness of draining process, and construction and operation cost of drainage system. Its two objectives are total cost of construction and operation and overall sojourn time of stormwater. An improved genetic algorithm is redesigned to solve this complex nondeterministic problem, which incorporates with stochastic and fuzzy characteristics in whole drainage process. A numerical example in Shanghai illustrates how to implement the model, and comparisons with alternative algorithms show its performance in computational flexibility and efficiency. Discussions on sensitivity of four main parameters, that is, quantity of pump stations, drainage pipe diameter, rainstorm precipitation intensity, and confidence levels, are also presented to provide guidance for designing urban drainage system.

  4. New Grapheme Generation Rules for Two-Stage Modelbased Grapheme-to-Phoneme Conversion

    Directory of Open Access Journals (Sweden)

    Seng Kheang

    2015-01-01

    Full Text Available The precise conversion of arbitrary text into its  corresponding phoneme sequence (grapheme-to-phoneme or G2P conversion is implemented in speech synthesis and recognition, pronunciation learning software, spoken term detection and spoken document retrieval systems. Because the quality of this module plays an important role in the performance of such systems and many problems regarding G2P conversion have been reported, we propose a novel two-stage model-based approach, which is implemented using an existing weighted finite-state transducer-based G2P conversion framework, to improve the performance of the G2P conversion model. The first-stage model is built for automatic conversion of words  to phonemes, while  the second-stage  model utilizes the input graphemes and output phonemes obtained from the first stage to determine the best final output phoneme sequence. Additionally, we designed new grapheme generation rules, which enable extra detail for the vowel and consonant graphemes appearing within a word. When compared with previous approaches, the evaluation results indicate that our approach using rules focusing on the vowel graphemes slightly improved the accuracy of the out-of-vocabulary dataset and consistently increased the accuracy of the in-vocabulary dataset.

  5. Cooperative Hierarchical PSO With Two Stage Variable Interaction Reconstruction for Large Scale Optimization.

    Science.gov (United States)

    Ge, Hongwei; Sun, Liang; Tan, Guozhen; Chen, Zheng; Chen, C L Philip

    2017-09-01

    Large scale optimization problems arise in diverse fields. Decomposing the large scale problem into small scale subproblems regarding the variable interactions and optimizing them cooperatively are critical steps in an optimization algorithm. To explore the variable interactions and perform the problem decomposition tasks, we develop a two stage variable interaction reconstruction algorithm. A learning model is proposed to explore part of the variable interactions as prior knowledge. A marginalized denoising model is proposed to construct the overall variable interactions using the prior knowledge, with which the problem is decomposed into small scale modules. To optimize the subproblems and relieve premature convergence, we propose a cooperative hierarchical particle swarm optimization framework, where the operators of contingency leadership, interactional cognition, and self-directed exploitation are designed. Finally, we conduct theoretical analysis for further understanding of the proposed algorithm. The analysis shows that the proposed algorithm can guarantee converging to the global optimal solutions if the problems are correctly decomposed. Experiments are conducted on the CEC2008 and CEC2010 benchmarks. The results demonstrate the effectiveness, convergence, and usefulness of the proposed algorithm.

  6. Autothermal two-stage gasification of low-density waste-derived fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hamel, Stefan [Universitaet Siegen, Institut fuer Energietechnik, Paul-Bonatz-Str. 9-11, D-57068 Siegen (Germany); Hasselbach, Holger [Universitaet Siegen, Institut fuer Energietechnik, Paul-Bonatz-Str. 9-11, D-57068 Siegen (Germany); Weil, Steffen [Universitaet Siegen, Institut fuer Energietechnik, Paul-Bonatz-Str. 9-11, D-57068 Siegen (Germany); Krumm, Wolfgang [Universitaet Siegen, Institut fuer Energietechnik, Paul-Bonatz-Str. 9-11, D-57068 Siegen (Germany)]. E-mail: w.krumm@et.mb.uni-siegen.de

    2007-02-15

    In order to increase the efficiency of waste utilization in thermal conversion processes, pre-treatment is advantageous. With the Herhof Stabilat[reg] process, residual domestic waste is upgraded to waste-derived fuel by means of biological drying and mechanical separation of inerts and metals. The dried and homogenized waste-derived Stabilat[reg] fuel has a relatively high calorific value and contains high volatile matter which makes it suitable for gasification. As a result of extensive mechanical treatment, the Stabilat[reg] produced is of a fluffy appearance with a low density. A two-stage gasifier, based on a parallel-arranged bubbling fluidized bed and a fixed bed reactor, has been developed to convert Stabilat[reg] into hydrogen-rich product gas. This paper focuses on the design and construction of the configured laboratory-scale gasifier and experience with its operation. The processing of low-density fluffy waste-derived fuel using small-scale equipment demands special technical solutions for the core components as well as for the peripheral equipment. These are discussed here. The operating results of Stabilat[reg] gasification are also presented.

  7. A two-stage visual tracking algorithm using dual-template

    Directory of Open Access Journals (Sweden)

    Yu Xia

    2016-10-01

    Full Text Available Template matching and updates are crucial steps in visual object tracking. In this article, we propose a two-stage object tracking algorithm using a dual-template. By design, the initial state of a target can be estimated using a prior fixed template at the first stage with a particle-filter-based tracking framework. The use of prior templates maintains the stability of an object tracking algorithm, because it consists of invariant and important features. In the second step, a mean shift is used to gain the optimal location of the object with the stage update template. The stage template improves the ability of target recognition using a classified update method. The complementary of dual-template improves the quality of template matching and the performance of object tracking. Experimental results demonstrate that the proposed algorithm improves the tracking performance in terms of accuracy and robustness, and it exhibits good results in the presence of deformation, noise and occlusion.

  8. TWO-STAGE PRODUCTION SCHEDULING WITH AN OPTION OF OUTSOURCING FROM A REMOTE SUPPLIER

    Institute of Scientific and Technical Information of China (English)

    Xiangtong QI

    2009-01-01

    This paper studies a two-stage production system with n job orders where each job needs two sequential operations. In addition to the two in-house production facilities, the manufacturer has another option of outsourcing some stage-one operations to a remote outside supplier. The jobs with their stage-one operations outsourced are subject to a batch transportation delay from the outside supplier before their respective stage-two operations can be started in-house. The problem is to design an integrated schedule that considers both the in-house production and the outsourcing with the aim of optimally balancing the outsourcing cost and the makespan. The problem is NP-hard. We have developed an optimal algorithm and a heuristic algorithm to solve the problem, and conducted computational experiments to validate our model and algorithms. Our modeling and algorithm framework can be extended to handle other more general cases such as when the outside supplier has a production facility with a different processing efficiency and when there are many outside suppliers on a spot market.

  9. 48 CFR 570.105-2 - Two-phase design-build selection procedures.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Two-phase design-build... ADMINISTRATION SPECIAL CONTRACTING PROGRAMS ACQUIRING LEASEHOLD INTERESTS IN REAL PROPERTY General 570.105-2 Two..., you must use the two-phase design-build selection procedures in section 303M of the Federal Property...

  10. Characterizing the Experimental Procedure in Science Laboratories: A Preliminary Step towards Students Experimental Design

    Science.gov (United States)

    Girault, Isabelle; d'Ham, Cedric; Ney, Muriel; Sanchez, Eric; Wajeman, Claire

    2012-01-01

    Many studies have stressed students' lack of understanding of experiments in laboratories. Some researchers suggest that if students design all or parts of entire experiment, as part of an inquiry-based approach, it would overcome certain difficulties. It requires that a procedure be written for experimental design. The aim of this paper is to…

  11. A Compact Two-Stage 120 W GaN High Power Amplifier for SweepSAR Radar Systems

    Science.gov (United States)

    Thrivikraman, Tushar; Horst, Stephen; Price, Douglas; Hoffman, James; Veilleux, Louise

    2014-01-01

    This work presents the design and measured results of a fully integrated switched power two-stage GaN HEMT high-power amplifier (HPA) achieving 60% power-added efficiency at over 120Woutput power. This high-efficiency GaN HEMT HPA is an enabling technology for L-band SweepSAR interferometric instruments that enable frequent repeat intervals and high-resolution imagery. The L-band HPA was designed using space-qualified state-of-the-art GaN HEMT technology. The amplifier exhibits over 34 dB of power gain at 51 dBm of output power across an 80 MHz bandwidth. The HPA is divided into two stages, an 8 W driver stage and 120 W output stage. The amplifier is designed for pulsed operation, with a high-speed DC drain switch operating at the pulsed-repetition interval and settles within 200 ns. In addition to the electrical design, a thermally optimized package was designed, that allows for direct thermal radiation to maintain low-junction temperatures for the GaN parts maximizing long-term reliability. Lastly, real radar waveforms are characterized and analysis of amplitude and phase stability over temperature demonstrate ultra-stable operation over temperature using integrated bias compensation circuitry allowing less than 0.2 dB amplitude variation and 2 deg phase variation over a 70 C range.

  12. CBR-Beta Design Procedure for Aggregate-Surfaced Airfield Pavements

    Science.gov (United States)

    2014-03-01

    ER D C/ G SL T R- 14 -6 CBR-Beta Design Procedure for Aggregate- Surfaced Airfield Pavements G eo te ch ni ca l a nd S tr uc tu re s...surfaces. The original flexible pavement design procedure of paved surfaces, which is based on the California Bearing Ratio (CBR) and the α-factor...Alpha-factor), was also extended and applied to the design and evaluation of aggregate-surfaced pavements . With the reformulation of the CBR-Alpha for

  13. TWO-STAGE SURGICAL TREATMENT OF A CHILD OF ONE YEAR FROM CONGENITAL HEART DISEASE AND BILIARY CIRRHOSIS

    Directory of Open Access Journals (Sweden)

    S. V. Gautier

    2014-01-01

    Full Text Available Aim: Clinical case of successful two-stage surgical treatment of a 1-year-old child with congenital heart disease and biliary cirrhosis is represented in this article. At the first day of life laparotomy was performed because of high intestinal obstruction. Kasai procedure and Roux-en-Y choledochojejunostomy were per- formed on 12th day and at the end of second month of life, respectively. Liver biopsy showed the signs of biliary cirrhosis. At the same time ventricular septal defect and atrial septal defect with pulmonary hyper- tension were diagnosed. The first step of treatment was the surgical septal defects closure. No complications during procedure, cardiopulmonary bypass and post-operative period were registered. There were no nega- tive effects on liver function after cardiac surgery. 11 months later living-donor liver transplantation was performed without any complications. Patient was discharged at 35th post-transplant day with stable graft function. 

  14. Automotic Recognition of Sleep Spindles Based on Two-Stage Classifier with Artificial Neural Networks and Support Vector Machines

    Directory of Open Access Journals (Sweden)

    MohammadHoseyn Khaksar

    2008-03-01

    Full Text Available Sleep spindles are one of the most important transient waveforms found in the sleep EEG signal. Here, we introduce a two-stage procedure based on artificial neural networks for the automatic recognition of sleep spindles (SS in a 19-channel electroencephalographic signal. In the first stage, a pre-processing perception is used for enhancing overall detection and also reducing computation time. In the second stage, the selected Sleep spindles (SS, classified with neural network post-classifier. Classifying tools in post-processing procedure were MLP and RBSVM that their operations are compared in the last section of the report. Visual inspection of 19-channel EEG from six subjects by one expert in this theme, showed that RBSVM operation is better than MLP with BP (Back propagation training, that SVM provided 91.4% average sensitivity and 3.85% average false detection rate.

  15. Procedure and information displays in advanced nuclear control rooms: experimental evaluation of an integrated design.

    Science.gov (United States)

    Chen, Yue; Gao, Qin; Song, Fei; Li, Zhizhong; Wang, Yufan

    2017-08-01

    In the main control rooms of nuclear power plants, operators frequently have to switch between procedure displays and system information displays. In this study, we proposed an operation-unit-based integrated design, which combines the two displays to facilitate the synthesis of information. We grouped actions that complete a single goal into operation units and showed these operation units on the displays of system states. In addition, we used different levels of visual salience to highlight the current unit and provided a list of execution history records. A laboratory experiment, with 42 students performing a simulated procedure to deal with unexpected high pressuriser level, was conducted to compare this design against an action-based integrated design and the existing separated-displays design. The results indicate that our operation-unit-based integrated design yields the best performance in terms of time and completion rate and helped more participants to detect unexpected system failures. Practitioner Summary: In current nuclear control rooms, operators frequently have to switch between procedure and system information displays. We developed an integrated design that incorporates procedure information into system displays. A laboratory study showed that the proposed design significantly improved participants' performance and increased the probability of detecting unexpected system failures.

  16. SUPPORTING THE INDUSTRY BY DEVELOPING A DESIGN GUIDANCE FOR COMPUTER-BASED PROCEDURES FOR FIELD WORKERS

    Energy Technology Data Exchange (ETDEWEB)

    Oxstrand, Johanna; LeBlanc, Katya

    2017-06-01

    The paper-based procedures currently used for nearly all activities in the commercial nuclear power industry have a long history of ensuring safe operation of the plants. However, there is potential to greatly increase efficiency and safety by improving how the human interacts with the procedures, which can be achieved through the use of computer-based procedures (CBPs). A CBP system offers a vast variety of improvements, such as context driven job aids, integrated human performance tools and dynamic step presentation. As a step toward the goal of improving procedure use performance, the U.S. Department of Energy Light Water Reactor Sustainability Program researchers, together with the nuclear industry, have been investigating the possibility and feasibility of replacing current paper-based procedures with CBPs. The main purpose of the CBP research conducted at the Idaho National Laboratory was to provide design guidance to the nuclear industry to be used by both utilities and vendors. After studying existing design guidance for CBP systems, the researchers concluded that the majority of the existing guidance is intended for control room CBP systems, and does not necessarily address the challenges of designing CBP systems for instructions carried out in the field. Further, the guidance is often presented on a high level, which leaves the designer to interpret what is meant by the guidance and how to specifically implement it. The authors developed a design guidance to provide guidance specifically tailored to instructions that are carried out in the field based.

  17. End-wall boundary layer measurements in a two-stage fan

    Science.gov (United States)

    Ball, C. L.; Reid, L.; Schmidt, J. F.

    1983-01-01

    Detailed flow measurements made in the casing boundary layer of a two-stage transonic fan are summarized. These measurements were taken at stations upstream of the fan, between all blade rows, and downstream of the last blade row. At the design tip speed of 429 m/sec the fan achieved a peak efficiency of 0.846 at a pressure ratio of 2.471. The boundary layer data were obtained at three weight flows at the design speed: one near choke flow, one near peak efficiency, and one near stall. Conventional boundary layer parameters were calculated from the data measured at each measuring station for each of the three flows. A classical two dimensional casing boundary layer was measured at the fan inlet and extended inward to approximately 15 percent of span. A highly three dimensional boundary layer was measured at the exit of each blade row and extended inward to approximately 10 percent of span. The steep radial gradient of axial velocity noted at the exit of the rotors was reduced substantially as the flow passed through the stators. This reduced gradient is attributed to flow mixing. The amount of flow mixing was reflected in the radial redistribution of total temperature as the flow passed through the stators. The data also show overturning of the tip flow at the stator exits that is consistent with the expected effect of the secondary flow field. The blockage factors calculated from the measured data show an increase in blockage across the rotors and a decrease across the stators.

  18. A Reconfigurable Architecture for Rotation Invariant Multi-View Face Detection Based on a Novel Two-Stage Boosting Method

    Directory of Open Access Journals (Sweden)

    Zhengbin Pang

    2009-01-01

    Full Text Available We present a reconfigurable architecture model for rotation invariant multi-view face detection based on a novel two-stage boosting method. A tree-structured detector hierarchy is designed to organize multiple detector nodes identifying pose ranges of faces. We propose a boosting algorithm for training the detector nodes. The strong classifier in each detector node is composed of multiple novelly designed two-stage weak classifiers. With a shared output space of multicomponents vector, each detector node deals with the multidimensional binary classification problems. The design of the hardware architecture which fully exploits the spatial and temporal parallelism is introduced in detail. We also study the reconfiguration of the architecture for finding an appropriate tradeoff among the hardware implementation cost, the detection accuracy, and speed. Experiments on FPGA show that high accuracy and marvelous speed are achieved compared with previous related works. The execution time speedups range from 14.68 to 20.86 for images with size of 160×120 up to 800×600 when our FPGA design (98 MHz is compared with software solution on PC (Pentium 4 2.8 GHz.

  19. Influence of one- or two-stage methods for polymerizing complete dentures on adaptation and teeth movements

    Directory of Open Access Journals (Sweden)

    Moises NOGUEIRA

    Full Text Available Abstract Introduction The quality of complete dentures might be influenced by the method of confection. Objective To evaluate the influence of two different methods of processing muco-supported complete dentures on their adaptation and teeth movements. Material and method Denture confection was assigned in two groups (n=10 for upper and lower arches according to polymerization method: 1 conventional one-stage - a wax trial base was made, teeth were arranged and polymerized; 2 two-stage method - the base was waxed and first polymerized. With the denture base polymerized, the teeth were arranged and then, performed the final polymerization. Teeth movements were evaluated in the distances between incisive (I-I, pre-molars (P-P, molars (M-M, left incisor to left molar (LI-LM and right incisor to right molar (RI-RM. For the adaptation analysis, dentures were cut in three different positions: (A distal face of canines, (B mesial face of the first molars, and (C distal face of second molars. Result Denture bases have shown a significant better adaptation when polymerized in the one-stage procedure for both the upper (p=0.000 and the lower (p=0.000 arches, with region A presenting significant better adaptation than region C. In the upper arch, significant reduction in the distance between I-I was observed in the one-stage technique, while the two-stage technique promoted significant reduction in the RI-RM distance. In the lower arch, one-stage technique promoted significant reduction in the distance for RI-RM and two-stage promoted significant reduction in the LI-LM distance. Conclusion Conventional one-stage method presented the better results for denture adaptation. Both fabrication methods presented some alteration in teeth movements.

  20. Enhancing the hydrolysis process of a two-stage biogas technology for the organic fraction of municipal solid waste

    DEFF Research Database (Denmark)

    Nasir, Zeeshan; Uellendahl, Hinrich

    2015-01-01

    The Danish company Solum A/S has developed a two-stage dry anaerobic digestion process labelled AIKAN® for the biological conversion of the organic fraction of municipal solid waste (OFMSW) into biogas and compost. In the AIKAN® process design the methanogenic (2nd) stage is separated from...... time, recirculation rate of percolate, ratio of admixing effluent from the anaerobic stage to the percolate, water submerge of waste) on the efficiency of the hydrolytic stage. •The effect of addition of adapted mixed cultures and specific hydrolytic microorganisms on the hydrolysis of the waste. •The...

  1. Two-stage plasma gun based on a gas discharge with a self-heating hollow emitter.

    Science.gov (United States)

    Vizir, A V; Tyunkov, A V; Shandrikov, M V; Oks, E M

    2010-02-01

    The paper presents the results of tests of a new compact two-stage bulk gas plasma gun. The plasma gun is based on a nonself-sustained gas discharge with an electron emitter based on a discharge with a self-heating hollow cathode. The operating characteristics of the plasma gun are investigated. The discharge system makes it possible to produce uniform and stable gas plasma in the dc mode with a plasma density up to 3x10(9) cm(-3) at an operating gas pressure in the vacuum chamber of less than 2x10(-2) Pa. The device features high power efficiency, design simplicity, and compactness.

  2. Method of oxygen-enriched two-stage underground coal gasification

    Institute of Scientific and Technical Information of China (English)

    Liu Hongtao; Chen Feng; Pan Xia; Yao Kai; Liu Shuqin

    2011-01-01

    Two-stage underground coal gasification was studied to improve the caloric value of the syngas and to extend gas production times. A model test using the oxygen-enriched two-stage coal gasification method was carried out. The composition of the gas produced, the time ratio of the two stages, and the role of the temperature field were analysed. The results show that oxygen-enriched two-stage gasification shortens the time of the first stage and prolongs the time of the second stage. Feed oxygen concentrations of 30%,35%, 40%, 45%, 60%, or 80% gave time ratios (first stage to second stage) of 1:0.12, 1:0.21, 1:0.51, 1:0.64,1:0.90, and 1:4.0 respectively. Cooling rates of the temperature field after steam injection decreased with time from about 19.1-27.4 ℃/min to 2.3-6.8 ℃/min. But this rate increased with increasing oxygen concentrations in the first stage. The caloric value of the syngas improves with increased oxygen concentration in the first stage. Injection of 80% oxygen-enriched air gave gas with the highest caloric value and also gave the longest production time. The caloric value of the gas obtained from the oxygenenriched two-stage gasification method lies in the range from 5.31 MJ/Nm3 to 10.54 MJ/Nm3.

  3. High magnetostriction parameters for low-temperature sintered cobalt ferrite obtained by two-stage sintering

    Energy Technology Data Exchange (ETDEWEB)

    Khaja Mohaideen, K.; Joy, P.A., E-mail: pa.joy@ncl.res.in

    2014-12-15

    From the studies on the magnetostriction characteristics of two-stage sintered polycrystalline CoFe{sub 2}O{sub 4} made from nanocrystalline powders, it is found that two-stage sintering at low temperatures is very effective for enhancing the density and for attaining higher magnetostriction coefficient. Magnetostriction coefficient and strain derivative are further enhanced by magnetic field annealing and relatively larger enhancement in the magnetostriction parameters is obtained for the samples sintered at lower temperatures, after magnetic annealing, despite the fact that samples sintered at higher temperatures show larger magnetostriction coefficients before annealing. A high magnetostriction coefficient of ∼380 ppm is obtained after field annealing for the sample sintered at 1100 °C, below a magnetic field of 400 kA/m, which is the highest value so far reported at low magnetic fields for sintered polycrystalline cobalt ferrite. - Highlights: • Effect of two-stage sintering on the magnetostriction characteristics of CoFe{sub 2}O{sub 4} is studied. • Two-stage sintering is very effective for enhancing the density and the magnetostriction parameters. • Higher magnetostriction for samples sintered at low temperatures and after magnetic field annealing. • Highest reported magnetostriction of 380 ppm at low fields after two-stage, low-temperature sintering.

  4. 13 K thermally coupled two-stage Stirling-type pulse tube refrigerator

    Institute of Scientific and Technical Information of China (English)

    TANG Ke; CHEN Guobang; THUMMES Günter

    2005-01-01

    Stirling-type pulse tube refrigerators have attracted academic and commercial interest in recent years due to their more compact configuration and higher efficiency than those of G-M type pulse tube refrigerators. In order to achieve a no-load cooling temperature below 20 K, a thermally coupled two-stage Stirling-type pulse tube refrigerator has been built. The thermally coupled arrangement was expected to minimize the interference between the two stages and to simplify the adjustment and optimization of the phase shifters. A no-load cooling temperature of 14.97 K has been realized with the two-stage cooler driven by one linear compressor of 200 W electric input. When the two stages are driven by two compressors respectively, with total electric input of 400 W, the prototype has attained a no-load cooling temperature of 12.96 K, which is the lowest temperature ever reported with two-stage Stirling-type pulse tube refrigerators.

  5. Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Ladan Jamshidy

    2016-01-01

    Full Text Available Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL regions by a stereomicroscope using a standard method. Results. The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion. The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique.

  6. A procedure for multi-objective optimization of tire design parameters

    Directory of Open Access Journals (Sweden)

    Nikola Korunović

    2015-04-01

    Full Text Available The identification of optimal tire design parameters for satisfying different requirements, i.e. tire performance characteristics, plays an essential role in tire design. In order to improve tire performance characteristics, formulation and solving of multi-objective optimization problem must be performed. This paper presents a multi-objective optimization procedure for determination of optimal tire design parameters for simultaneous minimization of strain energy density at two distinctive zones inside the tire. It consists of four main stages: pre-analysis, design of experiment, mathematical modeling and multi-objective optimization. Advantage of the proposed procedure is reflected in the fact that multi-objective optimization is based on the Pareto concept, which enables design engineers to obtain a complete set of optimization solutions and choose a suitable tire design. Furthermore, modeling of the relationships between tire design parameters and objective functions based on multiple regression analysis minimizes computational and modeling effort. The adequacy of the proposed tire design multi-objective optimization procedure has been validated by performing experimental trials based on finite element method.

  7. Power analysis for multivariate and repeated measures designs: a flexible approach using the SPSS MANOVA procedure.

    Science.gov (United States)

    D'Amico, E J; Neilands, T B; Zambarano, R

    2001-11-01

    Although power analysis is an important component in the planning and implementation of research designs, it is often ignored. Computer programs for performing power analysis are available, but most have limitations, particularly for complex multivariate designs. An SPSS procedure is presented that can be used for calculating power for univariate, multivariate, and repeated measures models with and without time-varying and time-constant covariates. Three examples provide a framework for calculating power via this method: an ANCOVA, a MANOVA, and a repeated measures ANOVA with two or more groups. The benefits and limitations of this procedure are discussed.

  8. Algorithmic Procedure to Design Water Utilization Systems Featuring Multiple Contaminants in Process Plants

    Institute of Scientific and Technical Information of China (English)

    王东明; 杨凤林; 张兴文

    2005-01-01

    This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utilization systems were first divided into three groups, then water-supply priority algorithm was proposed. The results of case studies showed that the water networks designed by this method gave water consumption lower than that estimated by other approaches. In addition, the procedure was subiect to no limitation on the problem scale.

  9. Two-stage open-loop velocity compensating method applied to multi-mass elastic transmission system

    Directory of Open Access Journals (Sweden)

    Zhang Deli

    2014-02-01

    Full Text Available In this paper, a novel vibration-suppression open-loop control method for multi-mass system is proposed, which uses two-stage velocity compensating algorithm and fuzzy I + P controller. This compensating method is based on model-based control theory in order to provide a damping effect on the system mechanical part. The mathematical model of multi-mass system is built and reduced to estimate the velocities of masses. The velocity difference between adjacent masses is calculated dynamically. A 3-mass system is regarded as the composition of two 2-mass systems in order to realize the two-stage compensating algorithm. Instead of using a typical PI controller in the velocity compensating loop, a fuzzy I + P controller is designed and its input variables are decided according to their impact on the system, which is different from the conventional fuzzy PID controller designing rules. Simulations and experimental results show that the proposed velocity compensating method is effective in suppressing vibration on a 3-mass system and it has a better performance when the designed fuzzy I + P controller is utilized in the control system.

  10. Effects of earthworm casts and zeolite on the two-stage composting of green waste.

    Science.gov (United States)

    Zhang, Lu; Sun, Xiangyang

    2015-05-01

    Because it helps protect the environment and encourages economic development, composting has become a viable method for organic waste disposal. The objective of this study was to investigate the effects of earthworm casts (EWCs) (at 0.0%, 0.30%, and 0.60%) and zeolite (clinoptilolite, CL) (at 0%, 15%, and 25%) on the two-stage composting of green waste. The combination of EWCs and CL improved the conditions of the composting process and the quality of the compost products in terms of the thermophilic phase, humification, nitrification, microbial numbers and enzyme activities, the degradation of cellulose and hemicellulose, and physico-chemical characteristics and nutrient contents of final composts. The compost matured in only 21days with the optimized two-stage composting method rather than in the 90-270days required for traditional composting. The optimal two-stage composting and the best quality compost were obtained with 0.30% EWCs and 25% CL.

  11. Two-Stage Revision Anterior Cruciate Ligament Reconstruction: Bone Grafting Technique Using an Allograft Bone Matrix.

    Science.gov (United States)

    Chahla, Jorge; Dean, Chase S; Cram, Tyler R; Civitarese, David; O'Brien, Luke; Moulton, Samuel G; LaPrade, Robert F

    2016-02-01

    Outcomes of primary anterior cruciate ligament (ACL) reconstruction have been reported to be far superior to those of revision reconstruction. However, as the incidence of ACL reconstruction is rapidly increasing, so is the number of failures. The subsequent need for revision ACL reconstruction is estimated to occur in up to 13,000 patients each year in the United States. Revision ACL reconstruction can be performed in one or two stages. A two-stage approach is recommended in cases of improper placement of the original tunnels or in cases of unacceptable tunnel enlargement. The aim of this study was to describe the technique for allograft ACL tunnel bone grafting in patients requiring a two-stage revision ACL reconstruction.

  12. The CSS and The Two-Staged Methods for Parameter Estimation in SARFIMA Models

    Directory of Open Access Journals (Sweden)

    Erol Egrioglu

    2011-01-01

    Full Text Available Seasonal Autoregressive Fractionally Integrated Moving Average (SARFIMA models are used in the analysis of seasonal long memory-dependent time series. Two methods, which are conditional sum of squares (CSS and two-staged methods introduced by Hosking (1984, are proposed to estimate the parameters of SARFIMA models. However, no simulation study has been conducted in the literature. Therefore, it is not known how these methods behave under different parameter settings and sample sizes in SARFIMA models. The aim of this study is to show the behavior of these methods by a simulation study. According to results of the simulation, advantages and disadvantages of both methods under different parameter settings and sample sizes are discussed by comparing the root mean square error (RMSE obtained by the CSS and two-staged methods. As a result of the comparison, it is seen that CSS method produces better results than those obtained from the two-staged method.

  13. Displacement-Based Seismic Design Procedure for Framed Buildings with Dissipative Braces Part II: Numerical Results

    Science.gov (United States)

    Mazza, Fabio; Vulcano, Alfonso

    2008-07-01

    For a widespread application of dissipative braces to protect framed buildings against seismic loads, practical and reliable design procedures are needed. In this paper a design procedure based on the Direct Displacement-Based Design approach is adopted, assuming the elastic lateral storey-stiffness of the damped braces proportional to that of the unbraced frame. To check the effectiveness of the design procedure, presented in an associate paper, a six-storey reinforced concrete plane frame, representative of a medium-rise symmetric framed building, is considered as primary test structure; this structure, designed in a medium-risk region, is supposed to be retrofitted as in a high-risk region, by insertion of diagonal braces equipped with hysteretic dampers. A numerical investigation is carried out to study the nonlinear static and dynamic responses of the primary and the damped braced test structures, using step-by-step procedures described in the associate paper mentioned above; the behaviour of frame members and hysteretic dampers is idealized by bilinear models. Real and artificial accelerograms, matching EC8 response spectrum for a medium soil class, are considered for dynamic analyses.

  14. Mapping hardwood forests through a two-stage unsupervised classification by integrating Landsat Thematic Mapper and forest inventory data

    Science.gov (United States)

    Shao, Gang; Pauli, Benjamin P.; Haulton, G. Scott; Zollner, Patrick A.; Shao, Guofan

    2014-01-01

    Sound forest management requires accurate forest maps at an appropriate scale. Forest cover data developed at a national scale may be too coarse for forest management at a local level. We demonstrated a two-stage unsupervised classification, integrating Continuous Forest Inventory (CFI) data and Landsat imageries, to classify forest types for Indiana State Forests (ISF) and 8-km surrounding areas. In the first stage, an automatic unsupervised classification assisted by CFI data was applied in ISF. In the second stage, the resultant forest cover information from the first stage was used to expand the classification area into the 8-km surrounding areas. Splitting the classification procedure into two stages made it possible to expand the classification area beyond the coverage of the CFI data. This data-aided unsupervised classification approach increased the repeatability of forest mapping. The resultant map contains five forest types: conifer, conifer-hardwood, maple, mixed hardwood, and oak-hickory forests. The overall accuracy was 81.9%, and the total disagreement was 0.176. The accuracies of conifer, conifer-hardwood, maple, mixed hardwood, and oak-hickory forests were 81.6, 63.4, 75.0, 33.3, and 90%, respectively. This forest mapping technique is suitable for automated mapping of forest areas where extensive plot data are available.

  15. Pilot plant testing of IGT`s two-stage fluidized-bed/cyclonic agglomerating combustor

    Energy Technology Data Exchange (ETDEWEB)

    Rehmat, A.; Mensinger, M.C. [Institute of Gas Technology, Chicago, IL (United States); Richardson, T.L. [Environmental Protection Agency, Cincinnati, OH (United States)

    1993-12-31

    The Institute of Gas Technology (IGT) is conducting a multi-year experimental program to develop and test, through pilot-scale operation, IGT`s two-stage fluidized-bed/cyclonic agglomerating combustor (AGGCOM). The AGGCOM process is based on combining the fluidized-bed agglomeration and gasification technology with the cyclonic combustion technology, both of which have been developed at IGT over many years. AGGCOM is a unique and extremely flexible combustor that can operate over a wide range of conditions in the fluidized-bed first stage from low temperature (desorption) to high temperature (agglomeration), including gasification of high-energy-content wastes. The ACCCOM combustor can easily and efficiently destroy solid, liquid, and gaseous organic wastes, while isolating solid inorganic contaminants within an essentially non-leachable glassy matrix, suitable for disposal in ordinary landfills. Fines elutriated from the first stage are captured by a high-efficiency cyclone and returned to the fluidized bed for ultimate incorporation into the agglomerates. Intense mixing in the second-stage cyclonic combustor ensures high destruction and removal efficiencies (DRE) for organic compounds that may be present in the feed material. This paper presents an overview of the experimental development of the AGGCOM process and progress made to date in designing, constructing, and operating the 6-ton/day AGGCOM pilot plant. Results of the bench-scale tests conducted to determine the operating conditions necessary to agglomerate a soil were presented at the 1991 Incineration Conference. On-site construction of the AGGCOM pilot plant was initiated in August 1992 and completed at the end of March 1993, with shakedown testing following immediately thereafter. The initial tests in the AGGCOM pilot plant will focus on the integrated operation of both stages of the combustor and will be conducted with ``clean`` topsoil.

  16. METHODOLOGY AND RESULTS OF MOBILE OBJECT PURSUIT PROBLEM SOLUTION WITH TWO-STAGE DYNAMIC SYSTEM

    Directory of Open Access Journals (Sweden)

    A. Kiselev Mikhail

    2017-01-01

    Full Text Available The experience of developing unmanned fighting vehicles indicates that the main challenge in this field reduces itself to creating the systems which can replace the pilot both as a sensor and as the operator of the flight. This problem can be partial- ly solved by introducing remote control, but there are certain flight segments where it can only be executed under fully inde- pendent control and data support due to various reasons, such as tight time, short duration, lack of robust communication, etc. Such stages also include close-range air combat maneuvering (CRACM - a key flight segment as far as the fighter's purpose is concerned, which also places the highest demands on the fighter's design. Until recently the creation of an unmanned fighter airplane has been a fundamentally impossible task due to the absence of sensors able to provide the necessary data support to control the fighter during CRACM. However, the development prospects of aircraft hardware (passive type flush antennae, op- tico-locating panoramic view stations are indicative of producing possible solutions to this problem in the nearest future. There- fore, presently the only fundamental impediment on the way to developing an unmanned fighting aircraft is the problem of cre- ating algorithms for automatic trajectory control during CRACM. This paper presents the strategy of automatic trajectory con- trol synthesis by a two-stage dynamic system aiming to reach the conditions specified with respect to an object in pursuit. It contains certain results of control algorithm parameters impact assessment in regards to the pursuit mission effectiveness. Based on the obtained results a deduction is drawn pertaining to the efficiency of the offered method and its possible utilization in au- tomated control of an unmanned fighting aerial vehicle as well as organizing group interaction during CRACM.

  17. Two-Stage Multi-Objective Collaborative Scheduling for Wind Farm and Battery Switch Station

    Directory of Open Access Journals (Sweden)

    Zhe Jiang

    2016-10-01

    Full Text Available In order to deal with the uncertainties of wind power, wind farm and electric vehicle (EV battery switch station (BSS were proposed to work together as an integrated system. In this paper, the collaborative scheduling problems of such a system were studied. Considering the features of the integrated system, three indices, which include battery swapping demand curtailment of BSS, wind curtailment of wind farm, and generation schedule tracking of the integrated system are proposed. In addition, a two-stage multi-objective collaborative scheduling model was designed. In the first stage, a day-ahead model was built based on the theory of dependent chance programming. With the aim of maximizing the realization probabilities of these three operating indices, random fluctuations of wind power and battery switch demand were taken into account simultaneously. In order to explore the capability of BSS as reserve, the readjustment process of the BSS within each hour was considered in this stage. In addition, the stored energy rather than the charging/discharging power of BSS during each period was optimized, which will provide basis for hour-ahead further correction of BSS. In the second stage, an hour-ahead model was established. In order to cope with the randomness of wind power and battery swapping demand, the proposed hour-ahead model utilized ultra-short term prediction of the wind power and the battery switch demand to schedule the charging/discharging power of BSS in a rolling manner. Finally, the effectiveness of the proposed models was validated by case studies. The simulation results indicated that the proposed model could realize complement between wind farm and BSS, reduce the dependence on power grid, and facilitate the accommodation of wind power.

  18. Study of high power, two-stage, TWT X-band amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P.; Golkowski, C.; Hayashi, Y.; Ivers, J.D.; Nation, J.A.; Schachter, L.

    1999-07-01

    A disk loaded slow wave structure with a cold wave phase (without electron beam) velocity of the TM{sub 01} wave greater than the speed of light (1.05c) is used as the electron bunching stage of a two stage X-band amplifier. The high phase velocity section produces well defined electron bunches. The second section, where the cold wave phase velocity is (0.84c), i.e., less than beam velocity of 0.91c, is used to generate the high output power microwave radiation. The tightly bunched beam from the high phase velocity section enhances the beam energy conversion into microwave radiation compared to that obtained with a synchronous electron-wave bunches. The amplifier is driven by a 7mm diameter 750 kV, 500A pencil electron beam. The structure, which has a 4 GHz bandwidth, produces an amplified output with a power in the range of 20--60 MW. At higher output powers (>60MW) pulse shortening develops. The authors suspect that the pulse shortening is a result of excitation of the hybrid mode, HEM{sub 11}, which overlaps (about 0.5 GHz separation) with the frequency domain of the desired TM{sub 0.1} mode. A new amplifier with similar phase velocity characteristics but with a 1 GHz bandwidth and an HEM{sub 11}, TM{sub 01} mode frequency separation of 3.3 GHz has been designed and constructed. The interaction frequency for the HEM mode is above the passband of the TM mode. Testing is in progress. The performance of the new amplifier will be compared with results obtained using the earlier configuration.

  19. The influence of Thomson effect in the performance optimization of a two stage thermoelectric cooler

    Science.gov (United States)

    Kaushik, S. C.; Manikandan, S.

    2015-12-01

    The exoreversible and irreversible thermodynamic models of a two stage thermoelectric cooler (TTEC) considering Thomson effect in conjunction with Peltier, Joule and Fourier heat conduction effects have been investigated using exergy analysis. New expressions for the interstage temperature, optimum current for the maximum cooling power, energy and exergy efficiency conditions, energy efficiency and exergy efficiency of a TTEC are derived as well. The number of thermocouples in the first and second stages of a TTEC for the maximum cooling power, energy and exergy efficiency conditions are optimized. The results show that the exergy efficiency is lower than the energy efficiency e.g., in an irreversible TTEC with total 30 thermocouples, heat sink temperature (TH) of 300 K and heat source temperature (TC) of 280 K, the obtained maximum cooling power, maximum energy and exergy efficiency are 20.37 W, 0.7147 and 5.10% respectively. It has been found that the Thomson effect increases the cooling power and energy efficiency of the TTEC system e.g., in the exoreversible TTEC the cooling power and energy efficiency increased from 14.87 W to 16.36 W and from 0.4079 to 0.4998 respectively for ΔTC of 40 K when Thomson effect is considered. It has also been found that the heat transfer area at the hot side of an irreversible TTEC should be higher than the cold side for maximum performance operation. This study will help in the designing of the actual multistage thermoelectric cooling systems.

  20. Methane production from sweet sorghum residues via a two-stage process

    Energy Technology Data Exchange (ETDEWEB)

    Stamatelatou, K.; Dravillas, K.; Lyberatos, G. [University of Patras (Greece). Department of Chemical Engineering, Laboratory of Biochemical Engineering and Environmental Technology

    2003-07-01

    The start-up of a two-stage reactor configuration for the anaerobic digestion of sweet sorghum residues was evaluated. The sweet sorghum residues were a waste stream originating from the alcoholic fermentation of sweet sorghum and the subsequent distillation step. This waste stream contained high concentration of solid matter (9% TS) and thus could be characterized as a semi-solid, not easily biodegradable wastewater with high COD (115 g/l). The application of the proposed two-stage configuration (consisting of one thermophilic hydrolyser and one mesophilic methaniser) achieved a methane production of 16 l/l wastewater under a hydraulic retention time of 19 d. (author)

  1. Two Stage Fully Differential Sample and Hold Circuit Using .18µm Technology

    Directory of Open Access Journals (Sweden)

    Dharmendra Dongardiye

    2014-05-01

    Full Text Available This paper presents a well-established Fully Differential sample & hold circuitry, implemented in 180-nm CMOS technology. In this two stage method the first stage give us very high gain and second stage gives large voltage swing. The proposed opamp provides 149MHz unity-gain bandwidth , 78 degree phase margin and a differential peak to peak output swing more than 2.4v. using the improved fully differential two stage operational amplifier of 76.7dB gain. Although the sample and hold circuit meets the requirements of SNR specifications.

  2. One-stage and two-stage penile buccal mucosa urethroplasty

    Directory of Open Access Journals (Sweden)

    G. Barbagli

    2016-03-01

    Full Text Available The paper provides the reader with the detailed description of current techniques of one-stage and two-stage penile buccal mucosa urethroplasty. The paper provides the reader with the preoperative patient evaluation paying attention to the use of diagnostic tools. The one-stage penile urethroplasty using buccal mucosa graft with the application of glue is preliminary showed and discussed. Two-stage penile urethroplasty is then reported. A detailed description of first-stage urethroplasty according Johanson technique is reported. A second-stage urethroplasty using buccal mucosa graft and glue is presented. Finally postoperative course and follow-up are addressed.

  3. Terephthalic acid wastewater treatment by using two-stage aerobic process

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Based on the tests between anoxic and aerobic process, the two-stage aerobic process with a biological selector was chosen to treat terephthalic acid wastewater (PTA). By adopting the two- stage aerobic process, the CODCr in PTA wastewater could be reduced from 4000-6000 mg/L to below 100 mg/L; the COD loading in the first aerobic tank could reach 7.0-8.0 kgCODCr/(m3.d) and that of the second stage was from 0.2 to 0.4 kgCODCr/(m3.d). Further researches on the kinetics of substrate degradation were carried out.

  4. Procedure for developing biological input for the design, location, or modification of water-intake structures

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, D.A.; McKenzie, D.H.

    1981-12-01

    To minimize adverse impact on aquatic ecosystems resulting from the operation of water intake structures, design engineers must have relevant information on the behavior, physiology and ecology of local fish and shellfish. Identification of stimulus/response relationships and the environmental factors that influence them is the first step in incorporating biological information in the design, location or modification of water intake structures. A procedure is presented in this document for providing biological input to engineers who are designing, locating or modifying a water intake structure. The authors discuss sources of stimuli at water intakes, historical approaches in assessing potential/actual impact and review biological information needed for intake design.

  5. Design, construction, and measurement of a dielectric single-mirror two-stage (DSMTS) photovoltaic concentrator

    Science.gov (United States)

    Mohedano Arroyo, Ruben; Benitez, Pablo; Minano, Juan C.; Bercero, Francisco; Lobato, Pablo

    2001-11-01

    The 30 X DSMTS is a trough-like photovoltaic concentrator, meant to track the sun in one axis, which has a mirror allocating two concentration stages and a secondary lens that increases its acceptance up to +/- 2.3 degrees. Provided that the sun subtends an angle of +/- 0.256 degrees, such acceptance seems excessive. However, thanks to it, we can relax requirements that often demand accuracy in systems of the kind. For instance, the shape of the mirror can be achieved by simply bending an aluminum sheet. To foresee the results we may expect of this strategy, we carried out some mechanical calculations, whose results are the boundary conditions that lead to a minimum standard deviation on the local slope of the elastic mirror with regards to the theoretical value. We checked by ray tracing that such an error actually provoked a small decrease on the acceptance. This fact persuaded us to carry out the manufacture of two elastic prototypes. In the test that have been performed so far with them we achieved an acceptance angle of +/- 1.63 degrees and a collection efficiency of 98 percent at a geometrical concentration of 30 times, results that can be considered as outstanding in the photovoltaics framework.

  6. A Two-Stage Intercontinental Ballistic Missile (ICBM) Design Optimization Study and Life Cycle Cost Analysis

    Science.gov (United States)

    1992-12-01

    dollars. 6.5 Summary of Results - The System Performance Matriz The results of the NEMESIS systems engineering study are summarized in Table 6.12. Note...Edition. Boston , MA: PWS Engineering, 1984. 43. Hall, A.D. "Three-Dimensional Morphology of Systems Engineering." IEEE Transactions on Systems, Science and

  7. First Law Analysis of a Two-stage Ejector-vapor Compression Refrigeration Cycle working with R404A

    National Research Council Canada - National Science Library

    Feiza Memet; Daniela-Elena Mitu

    2011-01-01

    The traditional two-stage vapor compression refrigeration cycle might be replaced by a two-stage ejector-vapor compression refrigeration cycle if it is aimed the decrease of irreversibility during expansion...

  8. Synthetic control charts with two-stage sampling for monitoring bivariate processes

    Directory of Open Access Journals (Sweden)

    Antonio F. B. Costa

    2007-04-01

    Full Text Available In this article, we consider the synthetic control chart with two-stage sampling (SyTS chart to control bivariate processes. During the first stage, one item of the sample is inspected and two correlated quality characteristics (x;y are measured. If the Hotelling statistic T1² for these individual observations of (x;y is lower than a specified value UCL1 the sampling is interrupted. Otherwise, the sampling goes on to the second stage, where the remaining items are inspected and the Hotelling statistic T2² for the sample means of (x;y is computed. When the statistic T2² is larger than a specified value UCL2, the sample is classified as nonconforming. According to the synthetic control chart procedure, the signal is based on the number of conforming samples between two neighbor nonconforming samples. The proposed chart detects process disturbances faster than the bivariate charts with variable sample size and it is from the practical viewpoint more convenient to administer.Este artigo apresenta um gráfico de controle com regra especial de decisão e amostragens em dois estágios para o monitoramento de processos bivariados. No primeiro estágio, um item da amostra é inspecionado e duas características de qualidade correlacionadas (x;y são medidas. Se a estatística de Hotelling T1² para as observações individuais de (x;y for menor que um valor especificado UCL1 a amostragem é interrompida. Caso contrário, a amostragem segue para o segundo estágio, onde os demais itens da amostra são inspecionados e a estatística de Hotelling T2² para as médias de (x;y é calculada. Quando a estatística T2² é maior que um valor especificado UCL2, a amostra é classificada como não conforme. De acordo com a regra especial de decisão, o alarme é baseado no número de amostras entre duas não conformes. O gráfico proposto é mais ágil e mais simples do ponto de vista operacional que o gráfico de controle bivariado com tamanho de amostras variável.

  9. Revisiting the Concepts "Approach", "Design" and "Procedure" According to the Richards and Rodgers (2011) Framework

    Science.gov (United States)

    Cumming, Brett

    2012-01-01

    The three concepts Approach, Design and Procedure as proposed in Rodgers' Framework are considered particularly effective as a framework in second language teaching with the specific aim of developing communication as well as for better understanding methodology in the use of communicative language use.

  10. The quality of procedures to assess and credit prior learning: Implications for design.

    NARCIS (Netherlands)

    Joosten-ten Brinke, Desirée; Sluijsmans, Dominique; Brand-Gruwel, Saskia; Jochems, Wim

    2008-01-01

    Joosten-ten Brinke, D., Sluijsmans, D. M. A., Brand-Gruwel, S., & Jochems, W. M. G. (2008). The quality of procedures to assess and credit prior learning: Implications for design. Educational Research Review, 3, 51-65. doi:10.1016/j.edurev.2007.08.001.

  11. Design of the exhale airway stents for emphysema (EASE) trial : an endoscopic procedure for reducing hyperinflation

    NARCIS (Netherlands)

    Shah, Pallav L.; Slebos, Dirk-Jan; Cardoso, Paulo F. G.; Cetti, Edward J.; Sybrecht, Gerhard W.; Cooper, Joel D.

    2011-01-01

    Background: Airway Bypass is a catheter-based, bronchoscopic procedure in which new passageways are created that bypass the collapsed airways, enabling trapped air to exit the lungs. The Exhale Airway Stents for Emphysema (EASE) Trial was designed to investigate whether Exhale (R) Drug-Eluting Stent

  12. DESIGN PROCEDURE OF SAFE LIFE AND PREDICTION OF DURABILITY OF MACHINES DETAILS AT FRICTION LOADING

    Directory of Open Access Journals (Sweden)

    В. Варюхно

    2011-04-01

    Full Text Available The aspects of prediction of durability of machines details are examined by friction loading. Onthe basis of used forecasts of change of object conditions the design procedure of safe life ofaviation engineering products, which works in conditions of friction loading. On the basis ofanalysis of the received results the theoretical model of prediction of the wear processes duringservice life is offered

  13. 28 CFR 54.135 - Designation of responsible employee and adoption of grievance procedures.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Designation of responsible employee and adoption of grievance procedures. 54.135 Section 54.135 Judicial Administration DEPARTMENT OF JUSTICE... equitable resolution of student and employee complaints alleging any action that would be prohibited...

  14. 24 CFR 3285.306 - Design procedures for concrete block piers.

    Science.gov (United States)

    2010-04-01

    ... piers less than 36 inches high are permitted to be constructed of single, open, or closed-cell concrete... shown in Figure A to this section. (3) The concrete blocks must be stacked with their hollow cells... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Design procedures for...

  15. A novel two-stage discrete crack method based on the screened Poisson equation and local mesh refinement

    Science.gov (United States)

    Areias, P.; Rabczuk, T.; de Sá, J. César

    2016-12-01

    We propose an alternative crack propagation algorithm which effectively circumvents the variable transfer procedure adopted with classical mesh adaptation algorithms. The present alternative consists of two stages: a mesh-creation stage where a local damage model is employed with the objective of defining a crack-conforming mesh and a subsequent analysis stage with a localization limiter in the form of a modified screened Poisson equation which is exempt of crack path calculations. In the second stage, the crack naturally occurs within the refined region. A staggered scheme for standard equilibrium and screened Poisson equations is used in this second stage. Element subdivision is based on edge split operations using a constitutive quantity (damage). To assess the robustness and accuracy of this algorithm, we use five quasi-brittle benchmarks, all successfully solved.

  16. Evaluating the impact of public subsidies on a firm’s performance: a two-stage quasi-experimental approach

    Directory of Open Access Journals (Sweden)

    Mauro Mediavilla

    2009-11-01

    Full Text Available In this paper we evaluate the effectiveness of regional R&D public programs in Catalonia (Spain with a two-stage procedure. Firstly, we compare the performance of publicly subsidised companies (treated with that of similar, but unsubsidised companies (non-treated. We use the Propensity Score Matching (PSM methodology to construct a control group which, with regard to its observable characteristics, is as similar as possible to the treated group, and that allows us to identify firms which maintain the same propensity to receive public subsidies. Secondly, and once a valid comparison group has been established, we compare the respective performance of each firm using regression techniques. As a result, we find that recipient firms, on average, seem to increase their value added as a direct result of public subsidy programs.

  17. Overcoming the bottlenecks of anaerobic digestion of olive mill solid waste by two-stage fermentation.

    Science.gov (United States)

    Stoyanova, Elitza; Lundaa, Tserennyam; Bochmann, Günther; Fuchs, Werner

    2017-02-01

    Two-stage anaerobic digestion (AD) of two-phase olive mill solid waste (OMSW) was applied for reducing the inhibiting factors by optimizing the acidification stage. Single-stage AD and co-fermentation with chicken manure were conducted coinstantaneous for direct comparison. Degradation of the polyphenols up to 61% was observed during the methanogenic stage. Nevertheless the concentration of phenolic substances was still high; the two-stage fermentation remained stable at OLR 1.5 kgVS/m³day. The buffer capacity of the system was twice as high, compared to the one-stage fermentation, without additives. The two-stage AD was a combined process - thermophilic first stage and mesophilic second stage, which pointed out to be the most profitable for AD of OMSW for the reduced hydraulic retention time (HRT) from 230 to 150 days, and three times faster than the single-stage and the co-fermentation start-up of the fermentation. The optimal HRT and incubation temperature for the first stage were determined to four days and 55°C. The performance of the two-stage AD concerning the stability of the process was followed by the co-digestion of OMSW with chicken manure as a nitrogen-rich co-substrate, which makes them viable options for waste disposal with concomitant energy recovery.

  18. Treatment of corn ethanol distillery wastewater using two-stage anaerobic digestion.

    Science.gov (United States)

    Ráduly, B; Gyenge, L; Szilveszter, Sz; Kedves, A; Crognale, S

    In this study the mesophilic two-stage anaerobic digestion (AD) of corn bioethanol distillery wastewater is investigated in laboratory-scale reactors. Two-stage AD technology separates the different sub-processes of the AD in two distinct reactors, enabling the use of optimal conditions for the different microbial consortia involved in the different process phases, and thus allowing for higher applicable organic loading rates (OLRs), shorter hydraulic retention times (HRTs) and better conversion rates of the organic matter, as well as higher methane content of the produced biogas. In our experiments the reactors have been operated in semi-continuous phase-separated mode. A specific methane production of 1,092 mL/(L·d) has been reached at an OLR of 6.5 g TCOD/(L·d) (TCOD: total chemical oxygen demand) and a total HRT of 21 days (5.7 days in the first-stage, and 15.3 days in the second-stage reactor). Nonetheless the methane concentration in the second-stage reactor was very high (78.9%); the two-stage AD outperformed the reference single-stage AD (conducted at the same reactor loading rate and retention time) by only a small margin in terms of volumetric methane production rate. This makes questionable whether the higher methane content of the biogas counterbalances the added complexity of the two-stage digestion.

  19. A two-stage ethanol-based biodiesel production in a packed bed reactor

    DEFF Research Database (Denmark)

    Xu, Yuan; Nordblad, Mathias; Woodley, John

    2012-01-01

    A two-stage enzymatic process for producing fatty acid ethyl ester (FAEE) in a packed bed reactor is reported. The process uses an experimental immobilized lipase (NS 88001) and Novozym 435 to catalyze transesterification (first stage) and esterification (second stage), respectively. Both stages...

  20. Two-Stage MAS Technique for Analysis of DRA Elements and Arrays on Finite Ground Planes

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2007-01-01

    A two-stage Method of Auxiliary Sources (MAS) technique is proposed for analysis of dielectric resonator antenna (DRA) elements and arrays on finite ground planes (FGPs). The problem is solved by first analysing the DRA on an infinite ground plane (IGP) and then using this solution to model the FGP...... problem....

  1. Use a Log Splitter to Demonstrate Two-Stage Hydraulic Pump

    Science.gov (United States)

    Dell, Timothy W.

    2012-01-01

    The two-stage hydraulic pump is commonly used in many high school and college courses to demonstrate hydraulic systems. Unfortunately, many textbooks do not provide a good explanation of how the technology works. Another challenge that instructors run into with teaching hydraulic systems is the cost of procuring an expensive real-world machine…

  2. Capacity Analysis of Two-Stage Production lines with Many Products

    NARCIS (Netherlands)

    M.B.M. de Koster (René)

    1987-01-01

    textabstractWe consider two-stage production lines with an intermediate buffer. A buffer is needed when fluctuations occur. For single-product production lines fluctuations in capacity availability may be caused by random processing times, failures and random repair times. For multi-product producti

  3. Kinetics analysis of two-stage austenitization in supermartensitic stainless steel

    DEFF Research Database (Denmark)

    Nießen, Frank; Villa, Matteo; Hald, John

    2017-01-01

    The martensite-to-austenite transformation in X4CrNiMo16-5-1 supermartensitic stainless steel was followed in-situ during isochronal heating at 2, 6 and 18 K min−1 applying energy-dispersive synchrotron X-ray diffraction at the BESSY II facility. Austenitization occurred in two stages, separated...

  4. Validation of Continuous CHP Operation of a Two-Stage Biomass Gasifier

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Jensen, Torben Kvist

    2006-01-01

    The Viking gasification plant at the Technical University of Denmark was built to demonstrate a continuous combined heat and power operation of a two-stage gasifier fueled with wood chips. The nominal input of the gasifier is 75 kW thermal. To validate the continuous operation of the plant, a 9-d...

  5. High rate treatment of terephthalic acid production wastewater in a two-stage anaerobic bioreactor

    NARCIS (Netherlands)

    Kleerebezem, R.; Beckers, J.; Pol, L.W.H.; Lettinga, G.

    2005-01-01

    The feasibility was studied of anaerobic treatment of wastewater generated during purified terephthalic acid (PTA) production in two-stage upflow anaerobic sludge blanket (UASB) reactor system. The artificial influent of the system contained the main organic substrates of PTA-wastewater: acetate, be

  6. ADM1-based modeling of methane production from acidified sweet sorghum extractin a two stage process

    DEFF Research Database (Denmark)

    Antonopoulou, Georgia; Gavala, Hariklia N.; Skiadas, Ioannis

    2012-01-01

    The present study focused on the application of the Anaerobic Digestion Model 1 οn the methane production from acidified sorghum extract generated from a hydrogen producing bioreactor in a two-stage anaerobic process. The kinetic parameters for hydrogen and volatile fatty acids consumption were...

  7. The rearrangement process in a two-stage broadcast switching network

    DEFF Research Database (Denmark)

    Jacobsen, Søren B.

    1988-01-01

    The rearrangement process in the two-stage broadcast switching network presented by F.K. Hwang and G.W. Richards (ibid., vol.COM-33, no.10, p.1025-1035, Oct. 1985) is considered. By defining a certain function it is possible to calculate an upper bound on the number of connections to be moved...

  8. Two-stage bargaining with coverage extension in a dual labour market

    DEFF Research Database (Denmark)

    Roberts, Mark A.; Stæhr, Karsten; Tranæs, Torben

    2000-01-01

    This paper studies coverage extension in a simple general equilibrium model with a dual labour market. The union sector is characterized by two-stage bargaining whereas the firms set wages in the non-union sector. In this model firms and unions of the union sector have a commonality of interest...

  9. Novel two-stage piezoelectric-based electrical energy generators for low and variable speed rotary machinery

    Science.gov (United States)

    Rastegar, J.; Murray, R.

    2010-04-01

    A novel class of two-stage piezoelectric-based electrical energy generators is presented for rotary machinery in which the input speed is low and varies significantly, even reversing. Applications include wind mills, turbo-machinery for harvesting tidal flows, etc. Current technology using magnet-and-coil rotary generators require gearing or similar mechanisms to increase the input speed and make the generation cycle efficient. Variable speed-control mechanisms are also usually needed to achieve high mechanical to electrical energy conversion efficiency. Presented here are generators that do not require gearing or speed control mechanisms, significantly reducing complexity and cost, especially pertaining to maintenance and service. Additionally, these new generators can expand the application of energy harvesting to much slower input speeds than current technology allows. The primary novelty of this technology is the two-stage harvesting system. The harvesting environment (e.g. wind) provides input to the primary system, which is then used to successively excite a secondary system of vibratory elements into resonance - like strumming a guitar. The key advantage is that by having two decoupled systems, the low-andvarying- speed input can be converted into constant and much higher frequency vibrations. Energy is then harvested from the secondary system's vibrating elements with high efficiency using piezoelectric elements or magnet-and-coil generators. These new generators are uncomplicated, and can efficiently operate at widely varying and even reversing input speeds. Conceptual designs are presented for a number of generators and subsystems (e.g. for passing mechanical energy from the primary to the secondary system). Additionally, analysis of a complete two-stage energy harvesting system is discussed with predictions of performance and efficiency.

  10. A comprehensive study of task coalescing for selecting parallelism granularity in a two-stage bidiagonal reduction

    KAUST Repository

    Haidar, Azzam

    2012-05-01

    We present new high performance numerical kernels combined with advanced optimization techniques that significantly increase the performance of parallel bidiagonal reduction. Our approach is based on developing efficient fine-grained computational tasks as well as reducing overheads associated with their high-level scheduling during the so-called bulge chasing procedure that is an essential phase of a scalable bidiagonalization procedure. In essence, we coalesce multiple tasks in a way that reduces the time needed to switch execution context between the scheduler and useful computational tasks. At the same time, we maintain the crucial information about the tasks and their data dependencies between the coalescing groups. This is the necessary condition to preserve numerical correctness of the computation. We show our annihilation strategy based on multiple applications of single orthogonal reflectors. Despite non-trivial characteristics in computational complexity and memory access patterns, our optimization approach smoothly applies to the annihilation scenario. The coalescing positively influences another equally important aspect of the bulge chasing stage: the memory reuse. For the tasks within the coalescing groups, the data is retained in high levels of the cache hierarchy and, as a consequence, operations that are normally memory-bound increase their ratio of computation to off-chip communication and become compute-bound which renders them amenable to efficient execution on multicore architectures. The performance for the new two-stage bidiagonal reduction is staggering. Our implementation results in up to 50-fold and 12-fold improvement (∼130 Gflop/s) compared to the equivalent routines from LAPACK V3.2 and Intel MKL V10.3, respectively, on an eight socket hexa-core AMD Opteron multicore shared-memory system with a matrix size of 24000 x 24000. Last but not least, we provide a comprehensive study on the impact of the coalescing group size in terms of cache

  11. Using automatic differentiation with the quasi-procedural method for multidisciplinary design optimaization

    Energy Technology Data Exchange (ETDEWEB)

    Altus, S.; Kroo, I. [Department of Aeronautics and Astronautics, Stanford Univ., Stanford, CA (United States); Bischof, C.; Hovland, P. [Mathematics and Computer Science Division, Argonne National Lab., Argonne, IL (United States)

    1996-02-01

    As computers have become increasingly powerful, the field of design optimization has moved toward higher fidelity models (involving many more variables) in the early stages of design. One way in which this movement has manifested itself is in the increasing popularity of multidisciplinary design optimization (MDO). Because the models used in MDO are large and very complicated, a modular design is desirable. Because there are many- design parameters to optimize, derivatives must be computed accurately and efficiently. This paper describes how the quasi-procedural program architecture developed by Takai and Kroo [9] and the technique of automatic differentiation [6] can be combined to effectively address these needs. The two techniques are explained, the manner in which they were integrated into a single framework is described, and the result of using this framework for an optimization problem in airplane design is presented.

  12. Research on the Procedure for Computer-Aided Pattern Design of Uygur's Flowered Hats

    Directory of Open Access Journals (Sweden)

    Shuxian Liu

    2013-05-01

    Full Text Available Xinjiang Uygur’s flowered hats is famous all over the world, it leads the world of headwear of variou nationalities within China by the variety of styles, the various ways of how to emroider pattern design and exquisite manufacture. It is unusual even in national costumes art of the world. The poupose of this study is to analyze Uygur's headwear, study the rules of Uygur's headwear pattern, analyze the characteristic of the basic pattern, research on the procedure for computer-aided pattern design of Uygur's flowered hat, explore the application of computer-aided design in traditional costume's pattern design and to realize application exploration of computer-aided design in designing of costume and dress adornment.

  13. Optimisation of two-stage screw expanders for waste heat recovery applications

    Science.gov (United States)

    Read, M. G.; Smith, I. K.; Stosic, N.

    2015-08-01

    It has previously been shown that the use of two-phase screw expanders in power generation cycles can achieve an increase in the utilisation of available energy from a low temperature heat source when compared with more conventional single-phase turbines. However, screw expander efficiencies are more sensitive to expansion volume ratio than turbines, and this increases as the expander inlet vapour dryness fraction decreases. For singlestage screw machines with low inlet dryness, this can lead to under expansion of the working fluid and low isentropic efficiency for the expansion process. The performance of the cycle can potentially be improved by using a two-stage expander, consisting of a low pressure machine and a smaller high pressure machine connected in series. By expanding the working fluid over two stages, the built-in volume ratios of the two machines can be selected to provide a better match with the overall expansion process, thereby increasing efficiency for particular inlet and discharge conditions. The mass flow rate though both stages must however be matched, and the compromise between increasing efficiency and maximising power output must also be considered. This research uses a rigorous thermodynamic screw machine model to compare the performance of single and two-stage expanders over a range of operating conditions. The model allows optimisation of the required intermediate pressure in the two- stage expander, along with the rotational speed and built-in volume ratio of both screw machine stages. The results allow the two-stage machine to be fully specified in order to achieve maximum efficiency for a required power output.

  14. Revised guideline for the approval procedure of package designs in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, F. [Federal Office for Radiation Protection, Salzgitter (Germany); Roedel, R. [Federal Inst. for Materials Research and Testing, Berlin (Germany)

    2004-07-01

    The IAEA Regulations for the Safe Transport of Radioactive Material, TS-R-1 are applied in Germany through the implementation of the Dangerous Goods Transport Regulations for class 7 of the International Modal Organisations (ADR, RID, IMDG-Code, ICAO-TI). Based on this the approval procedures for packages designs applied in Germany are in compliance with the provisions of TS-R-1. The Guideline R 003 issued by the Ministry of Transport, Building and Housing (BMVBW) in 1991 is the basis for the package design approval procedures in Germany. This Guideline has been reviewed and revised to reflect latest developments in the regulations as well as in the regulatory practice. In particular it has been extended to the approval procedures of Type C packages, packages subject to transitional arrangements, special form and low dispersible radioactive material and provides more detailed information to the applicant about the requested documentation. Publication of this revised guideline has been delayed but it is expected to take place in October 2004. The paper gives an overview about the main parts and provisions of this revised Guideline R 003 with the focus on package design approval procedures.

  15. Displacement-Based Seismic Design Procedure for Framed Buildings with Dissipative Braces Part I: Theoretical formulation

    Science.gov (United States)

    Mazza, Fabio; Vulcano, Alfonso

    2008-07-01

    The insertion of steel braces equipped with dissipative devices proves to be very effective in order to enhance the performance of a framed building under horizontal seismic loads. Multi-level design criteria were proposed according to the Performance-Based Design, in order to get, for a specific level of the seismic intensity, a designated performance objective of the building (e.g., an assigned damage level of either the framed structure or non-structural elements). In this paper a design procedure aiming to proportion braces with hysteretic dampers in order to attain, for a specific level of the seismic intensity, a designated performance level of the building is proposed. Exactly, a proportional stiffness criterion, which assumes the elastic lateral storey-stiffness due to the braces proportional to that of the unbraced frame, is combined with the Direct Displacement-Based Design, in which the design starts from target deformations. A computer code has been prepared for the nonlinear static and dynamic analyses, using a step-by-step procedure. Frame members and hysteretic dampers are idealized by bilinear models.

  16. Rock riprap design for protection of stream channels near highway structures; Volume 2, Evaluation of Riprap design procedures

    Science.gov (United States)

    Blodgett, J.C.; McConaughy, C.E.

    1986-01-01

    In volume 2, seven procedures now being used for design of rock riprap installations were evaluated using data from 26 field sites. Four basic types of riprap failures were identified: Particle erosion, translational slide, modified slump, and slump. Factors associated with riprap failure include stone size , bank side slope, size gradation, thickness, insufficient toe or endwall, failure of the bank material, overtopping during floods, and geomorphic changes in the channel. A review of field data and the design procedures suggests that estimates of hydraulic forces acting on the boundary based on flow velocity rather than shear stress are more reliable. Several adjustments for local conditions, such as channel curvature, superelevation, or boundary roughness, may be unwarranted in view of the difficulty in estimating critical hydraulic forces for which the riprap is to be designed. Success of the riprap is related not only to the appropriate procedure for selecting stone size, but also to the reliability of estimated hydraulic and channel factors applicable to the site. (See also W89-04910) (Author 's abstract)

  17. A New Soil Infiltration Technology for Decentralized Sewage Treatment: Two-Stage Anaerobic Tank and Soil Trench System

    Institute of Scientific and Technical Information of China (English)

    YE Chun; HU Zhan-Bo; KONG Hai-Nan; WANG Xin-Ze; HE Sheng-Bing

    2008-01-01

    The low removal efficiency of total nitrogen (TN) is one of the main disadvantages of traditional single stage subsurface infiltration system,which combines an anaerobic tank and a soil filter field.In this study,a full-scale,two-stage anaerobic tank and soil trench system was designed and operated to evaluate the feasibility and performances in treating sewage from a school campus for over a one-year monitoring period.The raw sewage was prepared and fed into the first anaerobic tank and second tank by 60% and 40%,respectively.This novel process could decrease chemical oxygen demand with the dichromate method by 89%-96%,suspended solids by 91%-97%,and total phosphorus by 91%-97%.The denitrification was satisfactory in the second stage soil trench,so the removals of TN as well as ammonia nitrogen (NH+4-N) reached 68%-75% and 96%-99%,respectively.It appeared that the removal efficiency of TN in this two-stage anaerobic tank and soil trench system was more effective than that in the single stage soil infiltration system.The effluent met the discharge standard for the sewage treatment plant (GB18918-2002) of China.

  18. ADM1-based modeling of methane production from acidified sweet sorghum extract in a two stage process.

    Science.gov (United States)

    Antonopoulou, Georgia; Gavala, Hariklia N; Skiadas, Ioannis V; Lyberatos, Gerasimos

    2012-02-01

    The present study focused on the application of the Anaerobic Digestion Model 1 on the methane production from acidified sorghum extract generated from a hydrogen producing bioreactor in a two-stage anaerobic process. The kinetic parameters for hydrogen and volatile fatty acids consumption were estimated through fitting of the model equations to the data obtained from batch experiments. The simulation of the continuous reactor performance at all HRTs tested (20, 15, and 10d) was very satisfactory. Specifically, the largest deviation of the theoretical predictions against the experimental data was 12% for the methane production rate at the HRT of 20d while the deviation values for the 15 and 10d HRT were 1.9% and 1.1%, respectively. The model predictions regarding pH, methane percentage in the gas phase and COD removal were in very good agreement with the experimental data with a deviation less than 5% for all steady states. Therefore, the ADM1 is a valuable tool for process design in the case of a two-stage anaerobic process as well.

  19. A two-stage approach for improved prediction of residue contact maps

    Directory of Open Access Journals (Sweden)

    Pollastri Gianluca

    2006-03-01

    Full Text Available Abstract Background Protein topology representations such as residue contact maps are an important intermediate step towards ab initio prediction of protein structure. Although improvements have occurred over the last years, the problem of accurately predicting residue contact maps from primary sequences is still largely unsolved. Among the reasons for this are the unbalanced nature of the problem (with far fewer examples of contacts than non-contacts, the formidable challenge of capturing long-range interactions in the maps, the intrinsic difficulty of mapping one-dimensional input sequences into two-dimensional output maps. In order to alleviate these problems and achieve improved contact map predictions, in this paper we split the task into two stages: the prediction of a map's principal eigenvector (PE from the primary sequence; the reconstruction of the contact map from the PE and primary sequence. Predicting the PE from the primary sequence consists in mapping a vector into a vector. This task is less complex than mapping vectors directly into two-dimensional matrices since the size of the problem is drastically reduced and so is the scale length of interactions that need to be learned. Results We develop architectures composed of ensembles of two-layered bidirectional recurrent neural networks to classify the components of the PE in 2, 3 and 4 classes from protein primary sequence, predicted secondary structure, and hydrophobicity interaction scales. Our predictor, tested on a non redundant set of 2171 proteins, achieves classification performances of up to 72.6%, 16% above a base-line statistical predictor. We design a system for the prediction of contact maps from the predicted PE. Our results show that predicting maps through the PE yields sizeable gains especially for long-range contacts which are particularly critical for accurate protein 3D reconstruction. The final predictor's accuracy on a non-redundant set of 327 targets is 35

  20. Matching tutor to student: rules and mechanisms for efficient two-stage learning in neural circuits

    CERN Document Server

    Tesileanu, Tiberiu; Balasubramanian, Vijay

    2016-01-01

    Existing models of birdsong learning assume that brain area LMAN introduces variability into song for trial-and-error learning. Recent data suggest that LMAN also encodes a corrective bias driving short-term improvements in song. These later consolidate in area RA, a motor cortex analogue downstream of LMAN. We develop a new model of such two-stage learning. Using a stochastic gradient descent approach, we derive how 'tutor' circuits should match plasticity mechanisms in 'student' circuits for efficient learning. We further describe a reinforcement learning framework with which the tutor can build its teaching signal. We show that mismatching the tutor signal and plasticity mechanism can impair or abolish learning. Applied to birdsong, our results predict the temporal structure of the corrective bias from LMAN given a plasticity rule in RA. Our framework can be applied predictively to other paired brain areas showing two-stage learning.

  1. HRI catalytic two-stage liquefaction (CTSL) process materials: chemical analysis and biological testing

    Energy Technology Data Exchange (ETDEWEB)

    Wright, C.W.; Later, D.W.

    1985-12-01

    This report presents data from the chemical analysis and biological testing of coal liquefaction materials obtained from the Hydrocarbon Research, Incorporated (HRI) catalytic two-stage liquefaction (CTSL) process. Materials from both an experimental run and a 25-day demonstration run were analyzed. Chemical methods of analysis included adsorption column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, low-voltage probe-inlet mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The biological activity was evaluated using the standard microbial mutagenicity assay and an initiation/promotion assay for mouse-skin tumorigenicity. Where applicable, the results obtained from the analyses of the CTSL materials have been compared to those obtained from the integrated and nonintegrated two-stage coal liquefaction processes. 18 refs., 26 figs., 22 tabs.

  2. Two-stage precipitation process of iron and arsenic from acid leaching solutions

    Institute of Scientific and Technical Information of China (English)

    N.J.BOLIN; J.E.SUNDKVIST

    2008-01-01

    A leaching process for base metals recovery often generates considerable amounts of impurities such as iron and arsenic into the solution.It is a challenge to separate the non-valuable metals into manageable and stable waste products for final disposal,without loosing the valuable constituents.Boliden Mineral AB has patented a two-stage precipitation process that gives a very clean iron-arsenic precipitate by a minimum of coprecipitation of base metals.The obtained product shows to have good sedimentation and filtration properties,which makes it easy to recover the iron-arsenic depleted solution by filtration and washing of the precipitate.Continuos bench scale tests have been done,showing the excellent results achieved by the two-stage precipitation process.

  3. Power Frequency Oscillation Suppression Using Two-Stage Optimized Fuzzy Logic Controller for Multigeneration System

    Directory of Open Access Journals (Sweden)

    Y. K. Bhateshvar

    2016-01-01

    Full Text Available This paper attempts to develop a linearized model of automatic generation control (AGC for an interconnected two-area reheat type thermal power system in deregulated environment. A comparison between genetic algorithm optimized PID controller (GA-PID, particle swarm optimized PID controller (PSO-PID, and proposed two-stage based PSO optimized fuzzy logic controller (TSO-FLC is presented. The proposed fuzzy based controller is optimized at two stages: one is rule base optimization and other is scaling factor and gain factor optimization. This shows the best dynamic response following a step load change with different cases of bilateral contracts in deregulated environment. In addition, performance of proposed TSO-FLC is also examined for ±30% changes in system parameters with different type of contractual demands between control areas and compared with GA-PID and PSO-PID. MATLAB/Simulink® is used for all simulations.

  4. A two-stage scheme for multi-view human pose estimation

    Science.gov (United States)

    Yan, Junchi; Sun, Bing; Liu, Yuncai

    2010-08-01

    We present a two-stage scheme integrating voxel reconstruction and human motion tacking. By combining voxel reconstruction with human motion tracking interactively, our method can work in a cluttered background where perfect foreground silhouettes are hardly available. For each frame, a silhouette-based 3D volume reconstruction method and hierarchical tracking algorithm are applied in two stages. In the first stage, coarse reconstruction and tracking results are obtained, and then the refinement for reconstruction is applied in the second stage. The experimental results demonstrate our approach is promising. Although our method focuses on the problem of human body voxel reconstruction and motion tracking in this paper, our scheme can be used to reconstruct voxel data and infer the pose of many specified rigid and articulated objects.

  5. Toward Improving Electrocardiogram (ECG) Biometric Verification using Mobile Sensors: A Two-Stage Classifier Approach.

    Science.gov (United States)

    Tan, Robin; Perkowski, Marek

    2017-02-20

    Electrocardiogram (ECG) signals sensed from mobile devices pertain the potential for biometric identity recognition applicable in remote access control systems where enhanced data security is demanding. In this study, we propose a new algorithm that consists of a two-stage classifier combining random forest and wavelet distance measure through a probabilistic threshold schema, to improve the effectiveness and robustness of a biometric recognition system using ECG data acquired from a biosensor integrated into mobile devices. The proposed algorithm is evaluated using a mixed dataset from 184 subjects under different health conditions. The proposed two-stage classifier achieves a total of 99.52% subject verification accuracy, better than the 98.33% accuracy from random forest alone and 96.31% accuracy from wavelet distance measure algorithm alone. These results demonstrate the superiority of the proposed algorithm for biometric identification, hence supporting its practicality in areas such as cloud data security, cyber-security or remote healthcare systems.

  6. Effect of two-stage aging on superplasticity of Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    LUO Zhi-hui; ZHANG Xin-ming; DU Yu-xuan; YE Ling-ying

    2006-01-01

    The effect of two-stage aging on the microstructures and superplasticity of 01420 Al-Li alloy was investigated by means of OM, TEM analysis and stretching experiment. The results demonstrate that the second phase particles distributed more uniformly with a larger volume fraction can be observed after the two-stage aging (120 ℃, 12 h+300 ℃, 36 h) compared with the single-aging(300 ℃, 48 h). After rolling and recrystallization annealing, fine grains with size of 8-10 μm are obtained, and the superplastic elongation of the specimens reaches 560% at strain rate of 8×10-4 s-1 and 480 ℃. Uniformly distributed fine particles precipitate both on grain boundaries and in grains at lower temperature. When the sheet is aged at high temperature, the particles become coarser with a large volume fraction.

  7. Two stage bioethanol refining with multi litre stacked microbial fuel cell and microbial electrolysis cell.

    Science.gov (United States)

    Sugnaux, Marc; Happe, Manuel; Cachelin, Christian Pierre; Gloriod, Olivier; Huguenin, Gérald; Blatter, Maxime; Fischer, Fabian

    2016-12-01

    Ethanol, electricity, hydrogen and methane were produced in a two stage bioethanol refinery setup based on a 10L microbial fuel cell (MFC) and a 33L microbial electrolysis cell (MEC). The MFC was a triple stack for ethanol and electricity co-generation. The stack configuration produced more ethanol with faster glucose consumption the higher the stack potential. Under electrolytic conditions ethanol productivity outperformed standard conditions and reached 96.3% of the theoretically best case. At lower external loads currents and working potentials oscillated in a self-synchronized manner over all three MFC units in the stack. In the second refining stage, fermentation waste was converted into methane, using the scale up MEC stack. The bioelectric methanisation reached 91% efficiency at room temperature with an applied voltage of 1.5V using nickel cathodes. The two stage bioethanol refining process employing bioelectrochemical reactors produces more energy vectors than is possible with today's ethanol distilleries.

  8. HRI catalytic two-stage liquefaction (CTSL) process materials: chemical analysis and biological testing

    Energy Technology Data Exchange (ETDEWEB)

    Wright, C.W.; Later, D.W.

    1985-12-01

    This report presents data from the chemical analysis and biological testing of coal liquefaction materials obtained from the Hydrocarbon Research, Incorporated (HRI) catalytic two-stage liquefaction (CTSL) process. Materials from both an experimental run and a 25-day demonstration run were analyzed. Chemical methods of analysis included adsorption column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, low-voltage probe-inlet mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The biological activity was evaluated using the standard microbial mutagenicity assay and an initiation/promotion assay for mouse-skin tumorigenicity. Where applicable, the results obtained from the analyses of the CTSL materials have been compared to those obtained from the integrated and nonintegrated two-stage coal liquefaction processes. 18 refs., 26 figs., 22 tabs.

  9. Performance measurement of insurance firms using a two-stage DEA method

    Directory of Open Access Journals (Sweden)

    Raha Jalili Sabet

    2013-01-01

    Full Text Available Measuring the relative performance of insurance firms plays an important role in this industry. In this paper, we present a two-stage data envelopment analysis to measure the performance of insurance firms, which were active over the period of 2006-2010. The proposed study of this paper performs DEA method in two stages where the first stage considers five inputs and three outputs while the second stage considers the outputs of the first stage as the inputs of the second stage and uses three different outputs for this stage. The results of our survey have indicated that while there were 4 efficient insurance firms most other insurances were noticeably inefficient. This means market was monopolized mostly by a limited number of insurance firms and competition was not fare enough to let other firms participate in economy, more efficiently.

  10. Direct Torque Control of Sensorless Induction Machine Drives: A Two-Stage Kalman Filter Approach

    Directory of Open Access Journals (Sweden)

    Jinliang Zhang

    2015-01-01

    Full Text Available Extended Kalman filter (EKF has been widely applied for sensorless direct torque control (DTC in induction machines (IMs. One key problem associated with EKF is that the estimator suffers from computational burden and numerical problems resulting from high order mathematical models. To reduce the computational cost, a two-stage extended Kalman filter (TEKF based solution is presented for closed-loop stator flux, speed, and torque estimation of IM to achieve sensorless DTC-SVM operations in this paper. The novel observer can be similarly derived as the optimal two-stage Kalman filter (TKF which has been proposed by several researchers. Compared to a straightforward implementation of a conventional EKF, the TEKF estimator can reduce the number of arithmetic operations. Simulation and experimental results verify the performance of the proposed TEKF estimator for DTC of IMs.

  11. Syme's two-stage amputation in insulin-requiring diabetics with gangrene of the forefoot.

    Science.gov (United States)

    Pinzur, M S; Morrison, C; Sage, R; Stuck, R; Osterman, H; Vrbos, L

    1991-06-01

    Thirty-five insulin-requiring adult diabetic patients underwent 38 Syme's Two-Stage amputations for gangrene of the forefoot with nonreconstructible peripheral vascular insufficiency. All had a minimum Doppler ischemic index of 0.5, serum albumin of 3.0 gm/dl, and total lymphocyte count of 1500. Thirty-one (81.6%) eventually healed and were uneventfully fit with a prosthesis. Regional anesthesia was used in all of the patients, with 22 spinal and 16 ankle block anesthetics. Twenty-seven (71%) returned to their preamputation level of ambulatory function. Six (16%) had major, and fifteen (39%) minor complications following the first stage surgery. The results of this study support the use of the Syme's Two-Stage amputation in adult diabetic patients with gangrene of the forefoot requiring amputation.

  12. Low-noise SQUIDs with large transfer: two-stage SQUIDs based on DROSs

    Science.gov (United States)

    Podt, M.; Flokstra, J.; Rogalla, H.

    2002-08-01

    We have realized a two-stage integrated superconducting quantum interference device (SQUID) system with a closed loop bandwidth of 2.5 MHz, operated in a direct voltage readout mode. The corresponding flux slew rate was 1.3×10 5Φ0/s and the measured white flux noise was 1.3 μ Φ0/√Hz at 4.2 K. The system is based on a conventional dc SQUID with a double relaxation oscillation SQUID (DROS) as the second stage. Because of the large flux-to-voltage transfer, the sensitivity of the system is completely determined by the sensor SQUID and not by the DROS or the room-temperature preamplifier. Decreasing the Josephson junction area enables a further improvement of the sensitivity of the two-stage SQUID systems.

  13. Experiment and surge analysis of centrifugal two-stage turbocharging system

    Institute of Scientific and Technical Information of China (English)

    Yituan HE; Chaochen MA

    2008-01-01

    To study a centrifugal two-stage turbocharging system's surge and influencing factors, a special test bench was set up and the system surge test was performed. The test results indicate that the measured parameters such as air mass flow and rotation speed of a high pressure (HP) stage compressor can be converted into corrected para-meters under a standard condition according to the Mach number similarity criterion, because the air flow in a HP stage compressor has entered the Reynolds number (Re) auto-modeling range. Accordingly, the reasons leading to a two-stage turbocharging system's surge can be analyzed according to the corrected mass flow characteristic maps and actual operating conditions of HP and low pressure (LP) stage compressors.

  14. Composite Motion Design Procedure for Vibration Assisted Small-Hole EDM Using One Voice Coil Motor

    Directory of Open Access Journals (Sweden)

    Jing Cui

    2016-01-01

    Full Text Available To address the problem of debris accumulation in small-hole electrical discharge machine (EDM and simplify the design of the spindle head, the paper proposes a novel composite motion design procedure integrated high frequency vibration and large stroke feed using one voice coil motor (VCM. Particularly, for the purposes of high servo accuracy and high frequency response of the composite motion, an improved zero-phase-error tracking controller (ZPETC algorithm decoupled with the feedback controller is developed for the process control, in which the feedback parameter adjustment is very simple to reduce the computation complexity. At last, the proposed procedure is validated by the experimental study of the established VCM positioning table; the results verify the efficiency of the proposed method.

  15. Hybrid staging of a Lysholm positive displacement engine with two Westinghouse two stage impulse Curtis turbines

    Energy Technology Data Exchange (ETDEWEB)

    Parker, D.A.

    1982-06-01

    The University of California at Berkeley has tested and modeled satisfactorly a hybrid staged Lysholm engine (positive displacement) with a two stage Curtis wheel turbine. The system operates in a stable manner over its operating range (0/1-3/1 water ratio, 120 psia input). Proposals are made for controlling interstage pressure with a partial admission turbine and volume expansion to control mass flow and pressure ratio for the Lysholm engine.

  16. Noncausal two-stage image filtration at presence of observations with anomalous errors

    Directory of Open Access Journals (Sweden)

    S. V. Vishnevyy

    2013-04-01

    Full Text Available Introduction. It is necessary to develop adaptive algorithms, which allow to detect such regions and to apply filter with respective parameters for suppression of anomalous noises for the purposes of image filtration, which consist of regions with anomalous errors. Development of adaptive algorithm for non-causal two-stage images filtration at pres-ence of observations with anomalous errors. The adaptive algorithm for noncausal two-stage filtration is developed. On the first stage the adaptive one-dimensional algorithm for causal filtration is used for independent processing along rows and columns of image. On the second stage the obtained data are united and a posteriori estimations are calculated. Results of experimental investigations. The developed adaptive algorithm for noncausal images filtration at presence of observations with anomalous errors is investigated on the model sample by means of statistical modeling on PC. The image is modeled as a realization of Gaussian-Markov random field. The modeled image is corrupted with uncorrelated Gaussian noise. Regions of image with anomalous errors are corrupted with uncorrelated Gaussian noise which has higher power than normal noise on the rest part of the image. Conclusions. The analysis of adaptive algorithm for noncausal two-stage filtration is done. The characteristics of accuracy of computed estimations are shown. The comparisons of first stage and second stage of the developed adaptive algorithm are done. Adaptive algorithm is compared with known uniform two-stage algorithm of image filtration. According to the obtained results the uniform algorithm does not suppress anomalous noise meanwhile the adaptive algorithm shows good results.

  17. Full noise characterization of a low-noise two-stage SQUID amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Falferi, P [Istituto di Fotonica e Nanotecnologie, CNR-Fondazione Bruno Kessler, 38100 Povo, Trento (Italy); Mezzena, R [INFN, Gruppo Collegato di Trento, Sezione di Padova, 38100 Povo, Trento (Italy); Vinante, A [INFN, Sezione di Padova, 35131 Padova (Italy)], E-mail: falferi@science.unitn.it

    2009-07-15

    From measurements performed on a low-noise two-stage SQUID amplifier coupled to a high- Q electrical resonator we give a complete noise characterization of the SQUID amplifier around the resonator frequency of 11 kHz in terms of additive, back action and cross-correlation noise spectral densities. The minimum noise temperature evaluated at 135 mK is 10 {mu}K and corresponds to an energy resolution of 18{Dirac_h}.

  18. Development of a Novel Type Catalyst SY-2 for Two-Stage Hydrogenation of Pyrolysis Gasoline

    Institute of Scientific and Technical Information of China (English)

    Wu Linmei; Zhang Xuejun; Zhang Zhihua; Wang Fucun

    2004-01-01

    By using the group ⅢB or groupⅦB metals and modulating the characteristics of electric charges on carrier surface, improving the catalyst preparation process and techniques for loading the active metal components, a novel type SY-2 catalyst earmarked for two-stage hydrogenation of pyrolysis gasoline has been developed. The catalyst evaluation results have indicated that the novel catalyst is characterized by a better hydrogenation reaction activity to give higher aromatic yield.

  19. Investigation on a two-stage solvay refrigerator with magnetic material regenerator

    Science.gov (United States)

    Chen, Guobang; Zheng, Jianyao; Zhang, Fagao; Yu, Jianping; Tao, Zhenshi; Ding, Cenyu; Zhang, Liang; Wu, Peiyi; Long, Yi

    This paper describes experimental results that the no-load temperature of a two-stage Solvay refrigerator has been reached in liquid helium temperature region from the original 11.5 K by using magnetic regenerative material instead of lead. The structure and technological characteristics of the prototype machine are presented. The effects of operating frequency and pressure on the refrigerating temperature have been discussed in this paper.

  20. Biological hydrogen production from olive mill wastewater with two-stage processes

    Energy Technology Data Exchange (ETDEWEB)

    Eroglu, Ela; Eroglu, Inci [Department of Chemical Engineering, Middle East Technical University, 06531, Ankara (Turkey); Guenduez, Ufuk; Yuecel, Meral [Department of Biology, Middle East Technical University, 06531, Ankara (Turkey); Tuerker, Lemi [Department of Chemistry, Middle East Technical University, 06531, Ankara (Turkey)

    2006-09-15

    In the present work two novel two-stage hydrogen production processes from olive mill wastewater (OMW) have been introduced. The first two-stage process involved dark-fermentation followed by a photofermentation process. Dark-fermentation by activated sludge cultures and photofermentation by Rhodobacter sphaeroides O.U.001 were both performed in 55ml glass vessels, under anaerobic conditions. In some cases of dark-fermentation, activated sludge was initially acclimatized to the OMW to provide the adaptation of microorganisms to the extreme conditions of OMW. The highest hydrogen production potential obtained was 29l{sub H{sub 2}}/l{sub OMW} after photofermentation with 50% (v/v) effluent of dark fermentation with activated sludge. Photofermentation with 50% (v/v) effluent of dark fermentation with acclimated activated sludge had the highest hydrogen production rate (0.008ll{sup -1}h{sup -1}). The second two-stage process involved a clay treatment step followed by photofermentation by R. sphaeroides O.U.001. Photofermentation with the effluent of the clay pretreatment process (4% (v/v)) gives the highest hydrogen production potential (35l{sub H{sub 2}}/l{sub OMW}), light conversion efficiency (0.42%) and COD conversion efficiency (52%). It was concluded that both pretreatment processes enhanced the photofermentative hydrogen production process. Moreover, hydrogen could be produced with highly concentrated OMW. Two-stage processes developed in the present investigation have a high potential for solving the environmental problems caused by OMW. (author)

  1. The two-stage aegean extension, from localized to distributed, a result of slab rollback acceleration

    OpenAIRE

    Brun, Jean-Pierre; Faccenna, Claudio; Gueydan, Frédéric; Sokoutis, Dimitrios; Philippon, Mélody; Kydonakis, Konstantinos; Gorini, Christian

    2016-01-01

    International audience; Back-arc extension in the Aegean, which was driven by slab rollback since 45 Ma, is described here for the first time in two stages. From Middle Eocene to Middle Miocene, deformation was localized leading to i) the exhumation of high-pressure metamorphic rocks to crustal depths, ii) the exhumation of high-temperature metamorphic rocks in core complexes and iii) the deposition of sedimentary basins. Since Middle Miocene, extension distributed over the whole Aegean domai...

  2. A Two-stage Discriminating Framework for Making Supply Chain Operation Decisions under Uncertainties

    OpenAIRE

    Gu, H; Rong, G

    2010-01-01

    This paper addresses the problem of making supply chain operation decisions for refineries under two types of uncertainties: demand uncertainty and incomplete information shared with suppliers and transport companies. Most of the literature only focus on one uncertainty or treat more uncertainties identically. However, we note that refineries have more power to control uncertainties in procurement and transportation than in demand in the real world. Thus, a two-stage framework for dealing wit...

  3. Low-noise SQUIDs with large transfer: two-stage SQUIDs based on DROSs

    NARCIS (Netherlands)

    Podt, M.; Flokstra, Jakob; Rogalla, Horst

    2002-01-01

    We have realized a two-stage integrated superconducting quantum interference device (SQUID) system with a closed loop bandwidth of 2.5 MHz, operated in a direct voltage readout mode. The corresponding flux slew rate was 1.3×105 Φ0/s and the measured white flux noise was 1.3 μΦ0/√Hz at 4.2 K. The

  4. Two stage dual gate MESFET monolithic gain control amplifier for Ka-band

    Science.gov (United States)

    Sokolov, V.; Geddes, J.; Contolatis, A.

    A monolithic two stage gain control amplifier has been developed using submicron gate length dual gate MESFETs fabricated on ion implanted material. The amplifier has a gain of 12 dB at 30 GHz with a gain control range of over 30 dB. This ion implanted monolithic IC is readily integrable with other phased array receiver functions such as low noise amplifiers and phase shifters.

  5. Exergy analysis of vapor compression refrigeration cycle with two-stage and intercooler

    Science.gov (United States)

    Kılıç, Bayram

    2012-07-01

    In this study, exergy analyses of vapor compression refrigeration cycle with two-stage and intercooler using refrigerants R507, R407c, R404a were carried out. The necessary thermodynamic values for analyses were calculated by Solkane program. The coefficient of performance, exergetic efficiency and total irreversibility rate of the system in the different operating conditions for these refrigerants were investigated. The coefficient of performance, exergetic efficiency and total irreversibility rate for alternative refrigerants were compared.

  6. Exergy analysis of vapor compression refrigeration cycle with two-stage and intercooler

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Bayram [Mehmet Akif Ersoy University, Bucak Emin Guelmez Vocational School, Bucak, Burdur (Turkey)

    2012-07-15

    In this study, exergy analyses of vapor compression refrigeration cycle with two-stage and intercooler using refrigerants R507, R407c, R404a were carried out. The necessary thermodynamic values for analyses were calculated by Solkane program. The coefficient of performance, exergetic efficiency and total irreversibility rate of the system in the different operating conditions for these refrigerants were investigated. The coefficient of performance, exergetic efficiency and total irreversibility rate for alternative refrigerants were compared. (orig.)

  7. Performance of Combined Water Turbine Darrieus-Savonius with Two Stage Savonius Buckets and Single Deflector

    OpenAIRE

    Sahim, Kaprawi; Santoso, Dyos; Sipahutar, Riman

    2016-01-01

    The objective of this study is to show the effect of single deflector plate on the performance of combined Darrieus-Savonius water turbine. In order to overcome the disadvantages of low torque of solo Darrieus turbine, a plate deflector mounted in front of returning Savonius bucket of combined water turbine composing of Darrieus and Savonius rotor has been proposed in this study. Some configurations of combined turbines with two stage Savonius rotors were experimentally tested in a river of c...

  8. Perceived Health Benefits and Soy Consumption Behavior: Two-Stage Decision Model Approach

    OpenAIRE

    Moon, Wanki; Balasubramanian, Siva K.; Rimal, Arbindra

    2005-01-01

    A two-stage decision model is developed to assess the effect of perceived soy health benefits on consumers' decisions with respect to soy food. The first stage captures whether or not to consume soy food, while the second stage reflects how often to consume. A conceptual/analytical framework is also employed, combining Lancaster's characteristics model and Fishbein's multi-attribute model. Results show that perceived soy health benefits significantly influence both decision stages. Further, c...

  9. High quantum efficiency mid-wavelength interband cascade infrared photodetectors with one and two stages

    Science.gov (United States)

    Zhou, Yi; Chen, Jianxin; Xu, Zhicheng; He, Li

    2016-08-01

    In this paper, we report on mid-wavelength infrared interband cascade photodetectors grown on InAs substrates. We studied the transport properties of the photon-generated carriers in the interband cascade structures by comparing two different detectors, a single stage detector and a two-stage cascade detector. The two-stage device showed quantum efficiency around 19.8% at room temperature, and clear optical response was measured even at a temperature of 323 K. The two detectors showed similar Johnson-noise limited detectivity. The peak detectivity of the one- and two-stage devices was measured to be 2.15 × 1014 cm·Hz1/02/W and 2.19 × 1014 cm·Hz1/02/W at 80 K, 1.21 × 109 cm·Hz1/02/W and 1.23 × 109 cm·Hz1/02/W at 300 K, respectively. The 300 K background limited infrared performance (BLIP) operation temperature is estimated to be over 140 K.

  10. Performance analysis of RDF gasification in a two stage fluidized bed-plasma process.

    Science.gov (United States)

    Materazzi, M; Lettieri, P; Taylor, R; Chapman, C

    2016-01-01

    The major technical problems faced by stand-alone fluidized bed gasifiers (FBG) for waste-to gas applications are intrinsically related to the composition and physical properties of waste materials, such as RDF. The high quantity of ash and volatile material in RDF can provide a decrease in thermal output, create high ash clinkering, and increase emission of tars and CO2, thus affecting the operability for clean syngas generation at industrial scale. By contrast, a two-stage process which separates primary gasification and selective tar and ash conversion would be inherently more forgiving and stable. This can be achieved with the use of a separate plasma converter, which has been successfully used in conjunction with conventional thermal treatment units, for the ability to 'polish' the producer gas by organic contaminants and collect the inorganic fraction in a molten (and inert) state. This research focused on the performance analysis of a two-stage fluid bed gasification-plasma process to transform solid waste into clean syngas. Thermodynamic assessment using the two-stage equilibrium method was carried out to determine optimum conditions for the gasification of RDF and to understand the limitations and influence of the second stage on the process performance (gas heating value, cold gas efficiency, carbon conversion efficiency), along with other parameters. Comparison with a different thermal refining stage, i.e. thermal cracking (via partial oxidation) was also performed. The analysis is supported by experimental data from a pilot plant.

  11. Continuous removal of endocrine disruptors by versatile peroxidase using a two-stage system.

    Science.gov (United States)

    Taboada-Puig, Roberto; Lu-Chau, Thelmo A; Eibes, Gemma; Feijoo, Gumersindo; Moreira, Maria T; Lema, Juan M

    2015-01-01

    The oxidant Mn(3+) -malonate, generated by the ligninolytic enzyme versatile peroxidase in a two-stage system, was used for the continuous removal of endocrine disrupting compounds (EDCs) from synthetic and real wastewaters. One plasticizer (bisphenol-A), one bactericide (triclosan) and three estrogenic compounds (estrone, 17β-estradiol, and 17α-ethinylestradiol) were removed from wastewater at degradation rates in the range of 28-58 µg/L·min, with low enzyme inactivation. First, the optimization of three main parameters affecting the generation of Mn(3+) -malonate (hydraulic retention time as well as Na-malonate and H2 O2 feeding rates) was conducted following a response surface methodology (RSM). Under optimal conditions, the degradation of the EDCs was proven at high (1.3-8.8 mg/L) and environmental (1.2-6.1 µg/L) concentrations. Finally, when the two-stage system was compared with a conventional enzymatic membrane reactor (EMR) using the same enzyme, a 14-fold increase of the removal efficiency was observed. At the same time, operational problems found during EDCs removal in the EMR system (e.g., clogging of the membrane and enzyme inactivation) were avoided by physically separating the stages of complex formation and pollutant oxidation, allowing the system to be operated for a longer period (∼8 h). This study demonstrates the feasibility of the two-stage enzymatic system for removing EDCs both at high and environmental concentrations.

  12. Rehabilitation outcomes in patients with early and two-stage reconstruction of flexor tendon injuries.

    Science.gov (United States)

    Sade, Ilgin; İnanir, Murat; Şen, Suzan; Çakmak, Esra; Kablanoğlu, Serkan; Selçuk, Barin; Dursun, Nigar

    2016-08-01

    [Purpose] The primary aim of this study was to assess rehabilitation outcomes for early and two-stage repair of hand flexor tendon injuries. The secondary purpose of this study was to compare the findings between treatment groups. [Subjects and Methods] Twenty-three patients were included in this study. Early repair (n=14) and two-stage repair (n=9) groups were included in a rehabilitation program that used hand splints. This retrospective evaluated patients according to their demographic characteristics, including age, gender, injured hand, dominant hand, cause of injury, zone of injury, number of affected fingers, and accompanying injuries. Pain, range of motion, and grip strength were evaluated using a visual analog scale, goniometer, and dynamometer, respectively. [Results] Both groups showed significant improvements in pain and finger flexion after treatment compared with baseline measurements. However, no significant differences were observed between the two treatment groups. Similar results were obtained for grip strength and pinch grip, whereas gross grip was better in the early tendon repair group. [Conclusion] Early and two-stage reconstruction of patients with flexor tendon injuries can be performed with similarly favorable responses and effective rehabilitation programs.

  13. A Comparison of Direct and Two-Stage Transportation of Patients to Hospital in Poland

    Directory of Open Access Journals (Sweden)

    Anna Rosiek

    2015-04-01

    Full Text Available Background: The rapid international expansion of telemedicine reflects the growth of technological innovations. This technological advancement is transforming the way in which patients can receive health care. Materials and Methods: The study was conducted in Poland, at the Department of Cardiology of the Regional Hospital of Louis Rydygier in Torun. The researchers analyzed the delay in the treatment of patients with acute coronary syndrome. The study was conducted as a survey and examined 67 consecutively admitted patients treated invasively in a two-stage transport system. Data were analyzed statistically. Results: Two-stage transportation does not meet the timeframe guidelines for the treatment of patients with acute myocardial infarction. Intervals for the analyzed group of patients were statistically significant (p < 0.0001. Conclusions: Direct transportation of the patient to a reference center with interventional cardiology laboratory has a significant impact on reducing in-hospital delay in case of patients with acute coronary syndrome. Perspectives: This article presents the results of two-stage transportation of the patient with acute coronary syndrome. This measure could help clinicians who seek to assess time needed for intervention. It also shows how time from the beginning of pain in chest is important and may contribute to patient disability, death or well-being.

  14. Two-stage residual inclusion estimation: addressing endogeneity in health econometric modeling.

    Science.gov (United States)

    Terza, Joseph V; Basu, Anirban; Rathouz, Paul J

    2008-05-01

    The paper focuses on two estimation methods that have been widely used to address endogeneity in empirical research in health economics and health services research-two-stage predictor substitution (2SPS) and two-stage residual inclusion (2SRI). 2SPS is the rote extension (to nonlinear models) of the popular linear two-stage least squares estimator. The 2SRI estimator is similar except that in the second-stage regression, the endogenous variables are not replaced by first-stage predictors. Instead, first-stage residuals are included as additional regressors. In a generic parametric framework, we show that 2SRI is consistent and 2SPS is not. Results from a simulation study and an illustrative example also recommend against 2SPS and favor 2SRI. Our findings are important given that there are many prominent examples of the application of inconsistent 2SPS in the recent literature. This study can be used as a guide by future researchers in health economics who are confronted with endogeneity in their empirical work.

  15. Study on two stage activated carbon/HFC-134a based adsorption chiller

    Science.gov (United States)

    >K Habib,

    2013-06-01

    In this paper, a theoretical analysis on the performance of a thermally driven two-stage four-bed adsorption chiller utilizing low-grade waste heat of temperatures between 50°C and 70°C in combination with a heat sink (cooling water) of 30°C for air-conditioning applications has been described. Activated carbon (AC) of type Maxsorb III/HFC-134a pair has been examined as an adsorbent/refrigerant pair. FORTRAN simulation program is developed to analyze the influence of operating conditions (hot and cooling water temperatures and adsorption/desorption cycle times) on the cycle performance in terms of cooling capacity and COP. The main advantage of this two-stage chiller is that it can be operational with smaller regenerating temperature lifts than other heat-driven single-stage chillers. Simulation results shows that the two-stage chiller can be operated effectively with heat sources of 50°C and 70°C in combination with a coolant at 30°C.

  16. Effects of earthworm casts and zeolite on the two-stage composting of green waste

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lu, E-mail: zhanglu1211@gmail.com; Sun, Xiangyang, E-mail: xysunbjfu@gmail.com

    2015-05-15

    Highlights: • Earthworm casts (EWCs) and clinoptilolite (CL) were used in green waste composting. • Addition of EWCs + CL improved physico-chemical and microbiological properties. • Addition of EWCs + CL extended the duration of thermophilic periods during composting. • Addition of EWCs + CL enhanced humification, cellulose degradation, and nutrients. • Combined addition of 0.30% EWCs + 25% CL reduced composting time to 21 days. - Abstract: Because it helps protect the environment and encourages economic development, composting has become a viable method for organic waste disposal. The objective of this study was to investigate the effects of earthworm casts (EWCs) (at 0.0%, 0.30%, and 0.60%) and zeolite (clinoptilolite, CL) (at 0%, 15%, and 25%) on the two-stage composting of green waste. The combination of EWCs and CL improved the conditions of the composting process and the quality of the compost products in terms of the thermophilic phase, humification, nitrification, microbial numbers and enzyme activities, the degradation of cellulose and hemicellulose, and physico-chemical characteristics and nutrient contents of final composts. The compost matured in only 21 days with the optimized two-stage composting method rather than in the 90–270 days required for traditional composting. The optimal two-stage composting and the best quality compost were obtained with 0.30% EWCs and 25% CL.

  17. A Two-stage injection-locked magnetron for accelerators with superconducting cavities

    CERN Document Server

    Kazakevich, Grigory; Flanagan, Gene; Marhauser, Frank; Neubauer, Mike; Yakovlev, Vyacheslav; Chase, Brian; Nagaitsev, Sergey; Pasquinelli, Ralph; Solyak, Nikolay; Tupikov, Vitali; Wolff, Daniel

    2013-01-01

    A concept for a two-stage injection-locked CW magnetron intended to drive Superconducting Cavities (SC) for intensity-frontier accelerators has been proposed. The concept considers two magnetrons in which the output power differs by 15-20 dB and the lower power magnetron being frequency-locked from an external source locks the higher power magnetron. The injection-locked two-stage CW magnetron can be used as an RF power source for Fermilab's Project-X to feed separately each of the 1.3 GHz SC of the 8 GeV pulsed linac. We expect output/locking power ratio of about 30-40 dB assuming operation in a pulsed mode with pulse duration of ~ 8 ms and repetition rate of 10 Hz. The experimental setup of a two-stage magnetron utilising CW, S-band, 1 kW tubes operating at pulse duration of 1-10 ms, and the obtained results are presented and discussed in this paper.

  18. Study on the Control Algorithm of Two-Stage DC-DC Converter for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Changhao Piao

    2014-01-01

    Full Text Available The fast response, high efficiency, and good reliability are very important characteristics to electric vehicles (EVs dc/dc converters. Two-stage dc-dc converter is a kind of dc-dc topologies that can offer those characteristics to EVs. Presently, nonlinear control is an active area of research in the field of the control algorithm of dc-dc converters. However, very few papers research on two-stage converter for EVs. In this paper, a fixed switching frequency sliding mode (FSFSM controller and double-integral sliding mode (DISM controller for two-stage dc-dc converter are proposed. And a conventional linear control (lag is chosen as the comparison. The performances of the proposed FSFSM controller are compared with those obtained by the lag controller. In consequence, the satisfactory simulation and experiment results show that the FSFSM controller is capable of offering good large-signal operations with fast dynamical responses to the converter. At last, some other simulation results are presented to prove that the DISM controller is a promising method for the converter to eliminate the steady-state error.

  19. Using mixed methods effectively in prevention science: designs, procedures, and examples.

    Science.gov (United States)

    Zhang, Wanqing; Watanabe-Galloway, Shinobu

    2014-10-01

    There is growing interest in using a combination of quantitative and qualitative methods to generate evidence about the effectiveness of health prevention, services, and intervention programs. With the emerging importance of mixed methods research across the social and health sciences, there has been an increased recognition of the value of using mixed methods for addressing research questions in different disciplines. We illustrate the mixed methods approach in prevention research, showing design procedures used in several published research articles. In this paper, we focused on two commonly used mixed methods designs: concurrent and sequential mixed methods designs. We discuss the types of mixed methods designs, the reasons for, and advantages of using a particular type of design, and the procedures of qualitative and quantitative data collection and integration. The studies reviewed in this paper show that the essence of qualitative research is to explore complex dynamic phenomena in prevention science, and the advantage of using mixed methods is that quantitative data can yield generalizable results and qualitative data can provide extensive insights. However, the emphasis of methodological rigor in a mixed methods application also requires considerable expertise in both qualitative and quantitative methods. Besides the necessary skills and effective interdisciplinary collaboration, this combined approach also requires an open-mindedness and reflection from the involved researchers.

  20. Dynamic Unfolding and the Conventions of Procedure: Geometric Proportioning Strategies in Gothic Architectural Design

    Directory of Open Access Journals (Sweden)

    Robert Bork

    2014-06-01

    Full Text Available This essay explores the proportioning strategies used by Gothic architects. It argues that Gothic design practice involved conventions of procedure, governing the dynamic unfolding of successive geometrical steps. Because this procedure proves difficult to capture in words, and because it produces forms with a qualitatively different kind of architectural order than the more familiar conventions of classical design, which govern the proportions of the final building rather than the logic of the steps used in creating it, Gothic design practice has been widely misunderstood since the Renaissance. Although some authors in the nineteenth and twentieth centuries attempted to sympathetically explain Gothic geometry, much of this work has been dismissed as unreliable, especially in the influential work of Konrad Hecht. This essay seeks to put the study of Gothic proportion onto a new and firmer foundation, by using computer-aided design software to analyze the geometry of carefully measured buildings and original design drawings. Examples under consideration include the parish church towers of Ulm and Freiburg, and the cross sections of the cathedrals of Reims, Prague, and Clermont-Ferrand, and of the Cistercian church at Altenberg. The sequence of images being analysed can be viewed as supplementary material at:http://dx.doi.org/10.5334/ah.bq.s1

  1. Two-stage urethroplasty is a better choice for proximal hypospadias with severe chordee after urethral plate transection: a single-center experience

    Science.gov (United States)

    Zheng, Da-Chao; Yao, Hai-Jun; Cai, Zhi-Kang; Da, Jun; Chen, Qi; Chen, Yan-Bo; Zhang, Ke; Xu, Ming-Xi; Lu, Mu-Jun; Wang, Zhong

    2015-01-01

    It is still debatable whether single- or two-stage urethroplasty is a more suitable technique for treating hypospadias with severe chordee after urethral plate transection. This retrospective study evaluated these two techniques. A total of 66 patients of proximal hypospadias with severe chordee were divided into two groups according to the techniques they underwent: 32 and 34 patients underwent single-stage (Duckett) or two-stage urethroplasty, respectively. Median ages at presentation were 7.5 years and 11.0 years in single-stage and two-stage repair groups, respectively. Median follow-ups were 28.5 months (20−60 months) and 35 months (18−60 months) in the single-stage and two-stage groups, respectively. The meatus of the neourethra was located at the top of the glans in all patients. No recurrence of chordee was found during follow-up, and all patients or parents were satisfied with the penile length and appearance. Complications were encountered in eight patients in both groups, with no statistically significant differences between the two techniques. The late complication rate of stricture was higher after the single-stage procedure (18.75% vs 0%). The complication rate after single-stage repairs was significantly lower in the prepubescent subgroup (10.52%) than in the postpubescent cohort (46.15%). These results indicate that the urethral plate transection effectively corrects severe chordee associated with proximal hypospadias during the intermediate follow-up period. Considering the higher rate of stricture after single-stage urethroplasty, two-stage urethroplasty is recommended for proximal hypospadias with severe chordee after urethral plate transection. PMID:25248656

  2. Robust parameter design for integrated circuit fabrication procedure with respect to categorical characteristic

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, S.Y

    1999-12-01

    We consider a robust parameter design of the process for forming contact windows in complementary metal-oxide semiconductor circuits. Robust design is often used to find the optimal levels of process conditions which would provide the output of consistent quality as close to a target value. In this paper, we analyze the results of the fractional factorial design of nine factors: mask dimension, viscosity, bake temperature, spin speed, bake time, aperture, exposure time, developing time, etch time, where the outcome of the experiment is measured in terms of a categorized window size with five categories. Random effect analysis is employed to model both the mean and variance of categorized window size as functions of some controllable factors as well as random errors. Empirical Bayes' procedures are then utilized to fit both the models, and to eventually find the robust design of CMOS circuit process by means of a Bootstrap resampling approach.

  3. PSP_MCSVM: brainstorming consensus prediction of protein secondary structures using two-stage multiclass support vector machines.

    Science.gov (United States)

    Chatterjee, Piyali; Basu, Subhadip; Kundu, Mahantapas; Nasipuri, Mita; Plewczynski, Dariusz

    2011-09-01

    Secondary structure prediction is a crucial task for understanding the variety of protein structures and performed biological functions. Prediction of secondary structures for new proteins using their amino acid sequences is of fundamental importance in bioinformatics. We propose a novel technique to predict protein secondary structures based on position-specific scoring matrices (PSSMs) and physico-chemical properties of amino acids. It is a two stage approach involving multiclass support vector machines (SVMs) as classifiers for three different structural conformations, viz., helix, sheet and coil. In the first stage, PSSMs obtained from PSI-BLAST and five specially selected physicochemical properties of amino acids are fed into SVMs as features for sequence-to-structure prediction. Confidence values for forming helix, sheet and coil that are obtained from the first stage SVM are then used in the second stage SVM for performing structure-to-structure prediction. The two-stage cascaded classifiers (PSP_MCSVM) are trained with proteins from RS126 dataset. The classifiers are finally tested on target proteins of critical assessment of protein structure prediction experiment-9 (CASP9). PSP_MCSVM with brainstorming consensus procedure performs better than the prediction servers like Predator, DSC, SIMPA96, for randomly selected proteins from CASP9 targets. The overall performance is found to be comparable with the current state-of-the art. PSP_MCSVM source code, train-test datasets and supplementary files are available freely in public domain at: http://sysbio.icm.edu.pl/secstruct and http://code.google.com/p/cmater-bioinfo/

  4. 23 CFR 636.210 - What requirements apply to projects which use the modified design-build procedure?

    Science.gov (United States)

    2010-04-01

    ... modified design-build procedure? 636.210 Section 636.210 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS DESIGN-BUILD CONTRACTING Selection Procedures, Award Criteria § 636.210 What requirements apply to projects which use the modified...

  5. 23 CFR 636.208 - May I use my existing prequalification procedures with design-build contracts?

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false May I use my existing prequalification procedures with design-build contracts? 636.208 Section 636.208 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS DESIGN-BUILD CONTRACTING Selection Procedures, Award...

  6. Identification of residual non-biodegradable organic compounds in wastewater effluent after two-stage biochemical treatment

    Directory of Open Access Journals (Sweden)

    Xuqing Liu

    2016-01-01

    Full Text Available The main non-biodegradable compounds (soluble microbial product – SMP of wastewater from the Maotai aromatic factories, located in the Chishui river region, were analyzed by UV spectroscopy, and by solid-phase extraction followed by gas chromatography coupled to mass spectrometry, after a two-stage biochemical treatment. The UV-Vis spectra revealed that the wastewater contained two double-bonds in conjugated systems (conjugated diene or α, β- unsaturated ketone, etc. and simple non-conjugated chromophores containing n electrons from carbonyl groups or the like. The residual organic non-biodegradable substances were identified using SPE-GC/MS analysis as complex polymers containing hydroxyl, carbonyl, and carboxyl functional groups with multiple connections to either benzene rings or heterocyclic rings. As these compounds are difficult to remove by conventional biochemical treatments, our findings provide a scientific basis for the design of efficient new strategies to remove SMP from wastewater.

  7. Economically efficient operation of two-stage fluidized-bed combustion systems; Wirtschaftliche Betriebsweise von zweistufigen Wirbelschicht-Verbrennungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, E. [Hoelter-ABT GmbH, Essen (Germany)

    1996-11-01

    Two-stage stationary fluidized-bed combustion is an efficient technology for thermal treatment of residues. This includes, e.g. sorted residues from industrial processes, materials soiled with coatings, varnishes or glues, biomass (wood, straw, hay) and packaging materials. A simple and robust design of the plant with few mobile parts ensures high availability, good performance, and low investment and operation cost. The modular structure contributes to this. (orig.) [Deutsch] Mit der gestuften stationaeren Wirbelschichtverbrennung stellt eine Technologie zur thermischen Verwertung von Reststoffen fuer vielfaeltige Einsatzbereiche zur Verfuegung. Dazu zaehlten zum Beispiel sortenreine Reststoffe aus der Industrieproduktion, durch Beschichtungen, Anstriche oder Klebstoffe verunreinigte Materialien, Biomassen (Holz, Stroh, Heu) und Verpackungsmittelrueckstaende. Ein einfacher und robuster Anlagenaufbau mit wenigen beweglichen Teilen gewaehrleistet eine hohe Betriebssicherheit sowie die Anlagenverfuegbarkeit und verringert gleichzeitig die Investitions- und Betriebskosten. Hierzu traegt auch der Aufbau aus verschiedenen, immer gleichartigen Funktionsmodulen bei. (orig.)

  8. A CFD Analysis of Steam Flow in the Two-Stage Experimental Impulse Turbine with the Drum Rotor Arrangement

    Science.gov (United States)

    Yun, Kukchol; Tajč, L.; Kolovratník, M.

    2016-03-01

    The aim of the paper is to present the CFD analysis of the steam flow in the two-stage turbine with a drum rotor and balancing slots. The balancing slot is a part of every rotor blade and it can be used in the same way as balancing holes on the classical rotor disc. The main attention is focused on the explanation of the experimental knowledge about the impact of the slot covering and uncovering on the efficiency of the individual stages and the entire turbine. The pressure and temperature fields and the mass steam flows through the shaft seals, slots and blade cascades are calculated. The impact of the balancing slots covering or uncovering on the reaction and velocity conditions in the stages is evaluated according to the pressure and temperature fields. We have also concentrated on the analysis of the seal steam flow through the balancing slots. The optimized design of the balancing slots has been suggested.

  9. An Application of Graphical Approach to Construct Multiple Testing Procedure in a Hypothetical Phase III Design

    Directory of Open Access Journals (Sweden)

    Naitee eTing

    2014-01-01

    Full Text Available Many multiple testing procedures (MTP have been developed in recent years. Among these new procedures, the graphical approach is flexible and easy to communicate with non-statisticians. A hypothetical Phase III clinical trial design is introduced in this manuscript to demonstrate how graphical approach can be applied in clinical product development. In this design, an active comparator is used. It is thought that this test drug under development could potentially be superior to this comparator. For comparison of efficacy, the primary endpoint is well established and widely accepted by regulatory agencies. However, an important secondary endpoint based on Phase II findings looks very promising. The target dose may have a good opportunity to deliver superiority to the comparator. Furthermore, a lower dose is included in case the target dose may demonstrate potential safety concerns. This Phase III study is designed as a non-inferiority trial with two doses, and two endpoints. This manuscript will illustrate how graphical approach is applied to this design in handling multiple testing issues.

  10. Development of the thermal behavior analysis code DIRAD and the fuel design procedure for LMFBR

    Science.gov (United States)

    Nakae, N.; Tanaka, K.; Nakajima, H.; Matsumoto, M.

    1992-06-01

    It is very important to increase the fuel linear heat rating for improvement of economy in LMFBR without any degradation in safety. A reduction of the design margin is helpful to achieve the high power operation. The development of a fuel design code and a design procedure is effective on the reduction of the design margin. The thermal behavior analysis code DIRAD has been developed with respect to fuel restructuring and gap conductance models. These models have been calibrated and revised using irradiation data of fresh fuel. It is, therefore, found that the code is applicable for the thermal analysis with fresh fuel. The uncertainties in fuel irradiation condition and fuel fabrication tolerance together with the uncertainty of the code prediction have major contributions to the design margin. In the current fuel design the first two uncertainties independently contribute to temperature increment. Another method which can rationally explain the effect of the uncertainties on the temperature increment is adopted here. Then, the design margin may be rationally reduced.

  11. Strength design of compliant towers including dynamic effects using an equivalent quasi-static design wave procedure

    Energy Technology Data Exchange (ETDEWEB)

    Vugts, J.H.; Dob, S.L.; Harland, L.A. [Delft Univ. of Technology, Civil Engineering Faculty, Delft (Netherlands)

    1997-12-31

    While there is great experience with the deterministic and quasi-static design wave method for the design of bottom founded offshore structures, the determination and inclusion of random dynamic effects in the design process is far less developed and only occasionally needed. An attractive procedure sometimes used is to determine an `inertial load set` that accounts for the effects of the dynamic response and to add this to the applied loading, after which the same design wave process could continue to be used. This engineering method is described and critically reviewed, after which it is applied to a conceptual design of a compliant tower in 600 m water depth West of the Shetlands Isles. This is a demanding test for the method and to verify the results these are compared with the results of random time domain simulations which serve as a reference. An ``inertial load set`` should only be expected to give satisfactory results for local responses when these remain to be governed by a predominant quasi-static contribution. (Author)

  12. Capacity expansion of stochastic power generation under two-stage electricity markets

    DEFF Research Database (Denmark)

    Pineda, Salvador; Morales González, Juan Miguel

    2016-01-01

    of stochastic power generating units. This framework includes the explicit representation of a day-ahead and a balancing market-clearing mechanisms to properly capture the impact of forecast errors of power production on the short-term operation of a power system. The proposed generation expansion problems...... are first formulated from the standpoint of a social planner to characterize a perfectly competitive market. We investigate the effect of two paradigmatic market designs on generation expansion planning: a day-ahead market that is cleared following a conventional cost merit-order principle, and an ideal...... market-clearing procedure that determines day-ahead dispatch decisions accounting for their impact on balancing operation costs. Furthermore, we reformulate the proposed models to determine the optimal expansion decisions that maximize the profit of a collusion of stochastic power producers in order...

  13. Two-Stage Power Factor Corrected Power Supplies: The Low Component-Stress Approach

    DEFF Research Database (Denmark)

    Petersen, Lars; Andersen, Michael Andreas E.

    2002-01-01

    The discussion concerning the use of single-stage contra two-stage PFC solutions has been going on for the last decade and it continues. The purpose of this paper is to direct the focus back on how the power is processed and not so much as to the number of stages or the amount of power processed....... The performance of the basic DC/DC topologies is reviewed with focus on the component stress. The knowledge obtained in this process is used to review some examples of the alternative PFC solutions and compare these solutions with the basic twostage PFC solution....

  14. Generalized Yule-walker and two-stage identification algorithms for dual-rate systems

    Institute of Scientific and Technical Information of China (English)

    Feng DING

    2006-01-01

    In this paper, two approaches are developed for directly identifying single-rate models of dual-rate stochastic systems in which the input updating frequency is an integer multiple of the output sampling frequency. The first is the generalized Yule-Walker algorithm and the second is a two-stage algorithm based on the correlation technique. The basic idea is to directly identify the parameters of underlying single-rate models instead of the lifted models of dual-rate systems from the dual-rate input-output data, assuming that the measurement data are stationary and ergodic. An example is given.

  15. Two-stage bargaining with coverage extension in a dual labour market

    DEFF Research Database (Denmark)

    Roberts, Mark A.; Stæhr, Karsten; Tranæs, Torben

    2000-01-01

    in extending coverage of a minimum wage to the non-union sector. Furthermore, the union sector does not seek to increase the non-union wage to a level above the market-clearing wage. In fact, it is optimal for the union sector to impose a market-clearing wage on the non-union sector. Finally, coverage......This paper studies coverage extension in a simple general equilibrium model with a dual labour market. The union sector is characterized by two-stage bargaining whereas the firms set wages in the non-union sector. In this model firms and unions of the union sector have a commonality of interest...

  16. Two-Stage Bulk Electron Heating in the Diffusion Region of Anti-Parallel Symmetric Reconnection

    CERN Document Server

    Le, Ari; Daughton, William

    2016-01-01

    Electron bulk energization in the diffusion region during anti-parallel symmetric reconnection entails two stages. First, the inflowing electrons are adiabatically trapped and energized by an ambipolar parallel electric field. Next, the electrons gain energy from the reconnection electric field as they undergo meandering motion. These collisionless mechanisms have been decribed previously, and they lead to highly-structured electron velocity distributions. Nevertheless, a simplified control-volume analysis gives estimates for how the net effective heating scales with the upstream plasma conditions in agreement with fully kinetic simulations and spacecraft observations.

  17. Use of two-stage membrane countercurrent cascade for natural gas purification from carbon dioxide

    Science.gov (United States)

    Kurchatov, I. M.; Laguntsov, N. I.; Karaseva, M. D.

    2016-09-01

    Membrane technology scheme is offered and presented as a two-stage countercurrent recirculating cascade, in order to solve the problem of natural gas dehydration and purification from CO2. The first stage is a single divider, and the second stage is a recirculating two-module divider. This scheme allows natural gas to be cleaned from impurities, with any desired degree of methane extraction. In this paper, the optimal values of the basic parameters of the selected technological scheme are determined. An estimation of energy efficiency was carried out, taking into account the energy consumption of interstage compressor and methane losses in energy units.

  18. Forecasting long memory series subject to structural change: A two-stage approach

    DEFF Research Database (Denmark)

    Papailias, Fotis; Dias, Gustavo Fruet

    2015-01-01

    A two-stage forecasting approach for long memory time series is introduced. In the first step, we estimate the fractional exponent and, by applying the fractional differencing operator, obtain the underlying weakly dependent series. In the second step, we produce multi-step-ahead forecasts...... for the weakly dependent series and obtain their long memory counterparts by applying the fractional cumulation operator. The methodology applies to both stationary and nonstationary cases. Simulations and an application to seven time series provide evidence that the new methodology is more robust to structural...... change and yields good forecasting results....

  19. Two-Stage Maximum Likelihood Estimation (TSMLE for MT-CDMA Signals in the Indoor Environment

    Directory of Open Access Journals (Sweden)

    Sesay Abu B

    2004-01-01

    Full Text Available This paper proposes a two-stage maximum likelihood estimation (TSMLE technique suited for multitone code division multiple access (MT-CDMA system. Here, an analytical framework is presented in the indoor environment for determining the average bit error rate (BER of the system, over Rayleigh and Ricean fading channels. The analytical model is derived for quadrature phase shift keying (QPSK modulation technique by taking into account the number of tones, signal bandwidth (BW, bit rate, and transmission power. Numerical results are presented to validate the analysis, and to justify the approximations made therein. Moreover, these results are shown to agree completely with those obtained by simulation.

  20. Two-Stage Electric Vehicle Charging Coordination in Low Voltage Distribution Grids

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    Increased environmental awareness in the recent years has encouraged rapid growth of renewable energy sources (RESs); especially solar PV and wind. One of the effective solutions to compensate intermittencies in generation from the RESs is to enable consumer participation in demand response (DR......). Being a sizable rated element, electric vehicles (EVs) can offer a great deal of demand flexibility in future intelligent grids. This paper first investigates and analyzes driving pattern and charging requirements of EVs. Secondly, a two-stage charging algorithm, namely local adaptive control...

  1. Influence of capacity- and time-constrained intermediate storage in two-stage food production systems

    DEFF Research Database (Denmark)

    Akkerman, Renzo; van Donk, Dirk Pieter; Gaalman, Gerard

    2007-01-01

    In food processing, two-stage production systems with a batch processor in the first stage and packaging lines in the second stage are common and mostly separated by capacity- and time-constrained intermediate storage. This combination of constraints is common in practice, but the literature hardly...... of systems like this. Contrary to the common sense in operations management, the LPT rule is able to maximize the total production volume per day. Furthermore, we show that adding one tank has considerable effects. Finally, we conclude that the optimal setup frequency for batches in the first stage...

  2. The global stability of a delayed predator-prey system with two stage-structure

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fengyan [College of Science, Jimei University, Xiamen Fujian 361021 (China)], E-mail: wangfy68@163.com; Pang Guoping [Department of Mathematics and Computer Science, Yulin Normal University, Yulin Guangxi 537000 (China)

    2009-04-30

    Based on the classical delayed stage-structured model and Lotka-Volterra predator-prey model, we introduce and study a delayed predator-prey system, where prey and predator have two stages, an immature stage and a mature stage. The time delays are the time lengths between the immature's birth and maturity of prey and predator species. Results on global asymptotic stability of nonnegative equilibria of the delay system are given, which generalize and suggest that good continuity exists between the predator-prey system and its corresponding stage-structured system.

  3. A Two-Stage Assembly-Type Flowshop Scheduling Problem for Minimizing Total Tardiness

    Directory of Open Access Journals (Sweden)

    Ju-Yong Lee

    2016-01-01

    Full Text Available This research considers a two-stage assembly-type flowshop scheduling problem with the objective of minimizing the total tardiness. The first stage consists of two independent machines, and the second stage consists of a single machine. Two types of components are fabricated in the first stage, and then they are assembled in the second stage. Dominance properties and lower bounds are developed, and a branch and bound algorithm is presented that uses these properties and lower bounds as well as an upper bound obtained from a heuristic algorithm. The algorithm performance is evaluated using a series of computational experiments on randomly generated instances and the results are reported.

  4. Biomass waste gasification - can be the two stage process suitable for tar reduction and power generation?

    Science.gov (United States)

    Sulc, Jindřich; Stojdl, Jiří; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiří; Vacek, Jiří; Skoblja, Siarhei; Buryan, Petr

    2012-04-01

    A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW(th). The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950°C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1-2 orders. On the other hand the two stage gasification (with overall ER=0.71) led to substantial reduction of gas heating value (LHV=3.15 MJ/Nm(3)), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950°C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the

  5. Two-stage continuous fermentation of Saccharomycopsis fibuligeria and Candida utilis.

    Science.gov (United States)

    Admassu, W; Korus, R A; Heimsch, R C

    1983-11-01

    Biomass production and carbohydrate reduction were determined for a two-stage continuous fermentation process with a simulated potato processing waste feed. The amylolytic yeast Saccharomycopsis fibuligera was grown in the first stage and a mixed culture of S. fibuligera and Candida utilis was maintained in the second stage. All conditions for the first and second stages were fixed except the flow of medium to the second stage was varied. Maximum biomass production occurred at a second stage dilution rate, D(2), of 0.27 h (-1). Carbohydrate reduction was inversely proportional to D(2), between 0.10 and 0.35 h (-1).

  6. Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis

    OpenAIRE

    Ladan Jamshidy; Hamid Reza Mozaffari; Payam Faraji; Roohollah Sharifi

    2016-01-01

    Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with ...

  7. An Investigation on the Formation of Carbon Nanotubes by Two-Stage Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    M. S. Shamsudin

    2012-01-01

    Full Text Available High density of carbon nanotubes (CNTs has been synthesized from agricultural hydrocarbon: camphor oil using a one-hour synthesis time and a titanium dioxide sol gel catalyst. The pyrolysis temperature is studied in the range of 700–900°C at increments of 50°C. The synthesis process is done using a custom-made two-stage catalytic chemical vapor deposition apparatus. The CNT characteristics are investigated by field emission scanning electron microscopy and micro-Raman spectroscopy. The experimental results showed that structural properties of CNT are highly dependent on pyrolysis temperature changes.

  8. FORMATION OF HIGHLY RESISTANT CARBIDE AND BORIDE COATINGS BY A TWO-STAGE DEPOSITION METHOD

    Directory of Open Access Journals (Sweden)

    W. I. Sawich

    2011-01-01

    Full Text Available A study was made of the aspects of forming highly resistant coatings in the surface zone of tool steels and solid carbide inserts by a two-stage method. at the first stage of the method, pure Ta or Nb coatings were electrodeposited on samples of tool steel and solid carbide insert in a molten salt bath containing Ta and Nb fluorides. at the second stage, the electrodeposited coating of Ta (Nb was subjected to carburizing or boriding to form carbide (TaC, NbC or boride (TaB, NbB cladding layers.

  9. Analysis and Design Procedure of LVLP Sub-bandgap Reference - Development and Results

    Directory of Open Access Journals (Sweden)

    T. Urban

    2011-04-01

    Full Text Available This work presents an thorough analysis and design of a low-voltage low-power voltage reference circuit with sub-bandgap output voltage. The outcome of the analysis and the resulting design rules are universal and it is supposed to be general and suitable for similar topologies with just minor modifications. The general analysis is followed by a selection of specific topology. The given topology is analyzed for particular parameters which are standard industrial circuit specifications. These parameters are mathematically expressed, some are simplified and equivalent circuits are used. The analysis and proposed design procedure focuses mainly on versatility of the IP block. The features of the circuit suit to low-voltage low-power design with less than 10μA supply current draw at 1.3V supply voltage. For testing purposes a complex transistor level design was created and verified in wide range of supply voltages (1.3 to 3.3V and temperatures (-45 to 95°C all in concrete 0.35μm IC design process using Mentor Graphics® and Cadence® software.

  10. Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process.

    Science.gov (United States)

    Grübel, Klaudiusz; Suschka, Jan

    2015-05-01

    The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning before applying hydrodynamic disintegration, as the pre-treatment procedure. Application of both processes as a hybrid disintegration sludge technology resulted in a higher organic matter release (soluble chemical oxygen demand (SCOD)) to the liquid sludge phase compared with the effects of processes conducted separately. The total SCOD after alkalization at 9 pH (pH in the range of 8.96-9.10, SCOD = 600 mg O2/L) and after hydrodynamic (SCOD = 1450 mg O2/L) disintegration equaled to 2050 mg/L. However, due to the synergistic effect, the obtained SCOD value amounted to 2800 mg/L, which constitutes an additional chemical oxygen demand (COD) dissolution of about 35 %. Similarly, the synergistic effect after alkalization at 10 pH was also obtained. The applied hybrid pre-hydrolysis technology resulted in a disintegration degree of 28-35%. The experiments aimed at selection of the most appropriate procedures in terms of optimal sludge digestion results, including high organic matter degradation (removal) and high biogas production. The analyzed soft hybrid technology influenced the effectiveness of mesophilic/thermophilic anaerobic digestion in a positive way and ensured the sludge minimization. The adopted pre-treatment technology (alkalization + hydrodynamic cavitation) resulted in 22-27% higher biogas production and 13-28% higher biogas yield. After two stages of anaerobic digestion (mesophilic conditions (MAD) + thermophilic anaerobic digestion (TAD)), the highest total solids (TS) reduction amounted to 45.6% and was received for the following sample at 7 days MAD + 17 days TAD. About 7% higher TS reduction was noticed compared with the sample after 9

  11. Efficiency and hardware comparison of analog control-based and digital control-based 70 W two-stage power factor corrector and DC-DC converters

    DEFF Research Database (Denmark)

    Török, Lajos; Munk-Nielsen, Stig

    2011-01-01

    A comparison of an analog and a digital controller driven 70 W two-stage power factor corrector converter is presented. Both controllers are operated in average current-mode-control for the PFC and peak current control for the DC-DC converter. Digital controller design and converter modeling is d...... is described. Results show that digital control can compete with the analog one in efficiency, PFC and THD.......A comparison of an analog and a digital controller driven 70 W two-stage power factor corrector converter is presented. Both controllers are operated in average current-mode-control for the PFC and peak current control for the DC-DC converter. Digital controller design and converter modeling...

  12. Evaluating procedural modelling for 3D models of informal settlements in urban design activities

    Directory of Open Access Journals (Sweden)

    Victoria Rautenbach

    2015-11-01

    Full Text Available Three-dimensional (3D modelling and visualisation is one of the fastest growing application fields in geographic information science. 3D city models are being researched extensively for a variety of purposes and in various domains, including urban design, disaster management, education and computer gaming. These models typically depict urban business districts (downtown or suburban residential areas. Despite informal settlements being a prevailing feature of many cities in developing countries, 3D models of informal settlements are virtually non-existent. 3D models of informal settlements could be useful in various ways, e.g. to gather information about the current environment in the informal settlements, to design upgrades, to communicate these and to educate inhabitants about environmental challenges. In this article, we described the development of a 3D model of the Slovo Park informal settlement in the City of Johannesburg Metropolitan Municipality, South Africa. Instead of using time-consuming traditional manual methods, we followed the procedural modelling technique. Visualisation characteristics of 3D models of informal settlements were described and the importance of each characteristic in urban design activities for informal settlement upgrades was assessed. Next, the visualisation characteristics of the Slovo Park model were evaluated. The results of the evaluation showed that the 3D model produced by the procedural modelling technique is suitable for urban design activities in informal settlements. The visualisation characteristics and their assessment are also useful as guidelines for developing 3D models of informal settlements. In future, we plan to empirically test the use of such 3D models in urban design projects in informal settlements.

  13. A flow channel design procedure for PEM fuel cells with effective water removal

    Science.gov (United States)

    Li, Xianguo; Sabir, Imran; Park, Jaewan

    Proper water management in polymer electrolyte membrane (PEM) fuel cells is critical to achieve the potential of PEM fuel cells. Membrane electrolyte requires full hydration in order to function as proton conductor, often achieved by fully humidifying the anode and cathode reactant gas streams. On the other hand, water is also produced in the cell due to electrochemical reaction. The combined effect is that liquid water forms in the cell structure and water flooding deteriorates the cell performance significantly. In the present study, a design procedure has been developed for flow channels on bipolar plates that can effectively remove water from the PEM fuel cells. The main design philosophy is based on the determination of an appropriate pressure drop along the flow channel so that all the liquid water in the cell is evaporated and removed from, or carried out of, the cell by the gas stream in the flow channel. At the same time, the gas stream in the flow channel is maintained fully saturated in order to prevent membrane electrolyte dehydration. Sample flow channels have been designed, manufactured and tested for five different cell sizes of 50, 100, 200, 300 and 441 cm 2. Similar cell performance has been measured for these five significantly different cell sizes, indicating that scaling of the PEM fuel cells is possible if liquid water flooding or membrane dehydration can be avoided during the cell operation. It is observed that no liquid water flows out of the cell at the anode and cathode channel exits for the present designed cells during the performance tests, and virtually no liquid water content in the cell structure has been measured by the neutron imaging technique. These measurements indicate that the present design procedure can provide flow channels that can effectively remove water in the PEM fuel cell structure.

  14. A flow channel design procedure for PEM fuel cells with effective water removal

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xianguo; Sabir, Imran; Park, Jaewan [Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2007-01-01

    Proper water management in polymer electrolyte membrane (PEM) fuel cells is critical to achieve the potential of PEM fuel cells. Membrane electrolyte requires full hydration in order to function as proton conductor, often achieved by fully humidifying the anode and cathode reactant gas streams. On the other hand, water is also produced in the cell due to electrochemical reaction. The combined effect is that liquid water forms in the cell structure and water flooding deteriorates the cell performance significantly. In the present study, a design procedure has been developed for flow channels on bipolar plates that can effectively remove water from the PEM fuel cells. The main design philosophy is based on the determination of an appropriate pressure drop along the flow channel so that all the liquid water in the cell is evaporated and removed from, or carried out of, the cell by the gas stream in the flow channel. At the same time, the gas stream in the flow channel is maintained fully saturated in order to prevent membrane electrolyte dehydration. Sample flow channels have been designed, manufactured and tested for five different cell sizes of 50, 100, 200, 300 and 441cm{sup 2}. Similar cell performance has been measured for these five significantly different cell sizes, indicating that scaling of the PEM fuel cells is possible if liquid water flooding or membrane dehydration can be avoided during the cell operation. It is observed that no liquid water flows out of the cell at the anode and cathode channel exits for the present designed cells during the performance tests, and virtually no liquid water content in the cell structure has been measured by the neutron imaging technique. These measurements indicate that the present design procedure can provide flow channels that can effectively remove water in the PEM fuel cell structure. (author)

  15. Research on the Procedure for Computer-Aided Pattern Design of Uygur's Flowered Hats

    OpenAIRE

    Shuxian Liu; Xiaohua Li

    2013-01-01

    Xinjiang Uygur’s flowered hats is famous all over the world, it leads the world of headwear of variou nationalities within China by the variety of styles, the various ways of how to emroider pattern design and exquisite manufacture. It is unusual even in national costumes art of the world. The poupose of this study is to analyze Uygur's headwear, study the rules of Uygur's headwear pattern, analyze the characteristic of the basic pattern, research on the procedure for computer-aided pattern d...

  16. Multiple testing procedures for identifying desirable dose combinations in bifactorial designs

    Directory of Open Access Journals (Sweden)

    Buchheister, Bettina

    2006-06-01

    Full Text Available Hung, Chi, and Lipicky proposed the AVE and MAX tests to analyse in a bifactorial design whether combinations of two drugs at several doses fulfil the desirable property of superiority to both their single drug components. These are global tests and do not identify the special combinations which are more effective than their respective single components. Here multiple testing procedures based on linear contrast tests and on the closed testing principle will be presented. They will be compared with simultaneous Min tests of Laska and Meisner. The performance of these approaches is investigated by simulation studies.

  17. Design and evaluation of computerized operating procedures in nuclear power plants.

    Science.gov (United States)

    Hwang, Fei-Hui; Hwang, Sheue-Ling

    2003-01-15

    A small-scale virtual system has been developed in this study to enhance operators' understanding and operating performance. For this, a computerized graphical interface based on Dynamic Work Causality Equation (DWCE) has been designed to transform the operating procedure into a flowchart. Furthermore, the Programmable Logic Controller (PLC) was installed to connect the signboard (proposed system) with the computerized graphical interface. An experiment was conducted to verify the effect of computerized graphic interface, indicating that the computerized system significantly decreases learning time and improves operational performance.

  18. Experimental Technique of Two-Stage Electric Gun%二级电炮加载技术研究

    Institute of Scientific and Technical Information of China (English)

    罗斌强; 赵剑衡; 孙承纬; 莫建军; 贺佳; 张兴卫; 王桂吉; 谭福利

    2012-01-01

    利用常规电炮发射金属飞片的实验技术,将Ф10mm×0.5mm、Ф10mm×0.3mm铝飞片分别发射到300、500m/s的速度且具有较好的平面度,有效拓展了电炮在相对较低的飞片发射速度和较低应变率下的加载能力(飞片速度约100m/s、应变率小于106 s-1),使之可以在更宽的应变率和加载压力下使用。利用二级电炮技术,对Zr51Ti5Ni10Cu25Al9块体非晶合金进行了平面撞击实验,获得了较好的结果,该工作对电炮加载技术的推广应用有着重要的作用。%A newly designed configuration based on an electric gun (namely two-stage electric gun) was used to launch metallic flyer,and dimension ofФ510 mm×0.5 mm,Ф510 mm×0.3 mm aluminum flyers can be accelerated to 300 m/s and 500 m/s, respectively. Using the two stage electric gun, dynamic response of Zr-based amorphous alloy was investigated under planar impact and good results were obtained. This work extended the capability of electric gun to contain wider range of planer flyer velocity(0. 1-10 km/s) and loading strain rates(10s-106 s Z),and it may be helpful to planer-impact experiments.

  19. Efficiency and hardware comparison of analog control-based and digital control-based 70 W two-stage power factor corrector and DC-DC converters

    DEFF Research Database (Denmark)

    Török, Lajos; Munk-Nielsen, Stig

    2011-01-01

    A comparison of an analog and a digital controller driven 70 W two-stage power factor corrector converter is presented. Both controllers are operated in average current-mode-control for the PFC and peak current control for the DC-DC converter. Digital controller design and converter modeling...... is described. Results show that digital control can compete with the analog one in efficiency, PFC and THD....

  20. Complex Dynamical Behavior of a Two-Stage Colpitts Oscillator with Magnetically Coupled Inductors

    Directory of Open Access Journals (Sweden)

    V. Kamdoum Tamba

    2014-01-01

    Full Text Available A five-dimensional (5D controlled two-stage Colpitts oscillator is introduced and analyzed. This new electronic oscillator is constructed by considering the well-known two-stage Colpitts oscillator with two further elements (coupled inductors and variable resistor. In contrast to current approaches based on piecewise linear (PWL model, we propose a smooth mathematical model (with exponential nonlinearity to investigate the dynamics of the oscillator. Several issues, such as the basic dynamical behaviour, bifurcation diagrams, Lyapunov exponents, and frequency spectra of the oscillator, are investigated theoretically and numerically by varying a single control resistor. It is found that the oscillator moves from the state of fixed point motion to chaos via the usual paths of period-doubling and interior crisis routes as the single control resistor is monitored. Furthermore, an experimental study of controlled Colpitts oscillator is carried out. An appropriate electronic circuit is proposed for the investigations of the complex dynamics behaviour of the system. A very good qualitative agreement is obtained between the theoretical/numerical and experimental results.

  1. Optimization of Two-Stage Peltier Modules: Structure and Exergetic Efficiency

    Directory of Open Access Journals (Sweden)

    Cesar Ramirez-Lopez

    2012-08-01

    Full Text Available In this paper we undertake the theoretical analysis of a two-stage semiconductor thermoelectric module (TEM which contains an arbitrary and different number of thermocouples, n1 and n2, in each stage (pyramid-styled TEM. The analysis is based on a dimensionless entropy balance set of equations. We study the effects of n1 and n2, the flowing electric currents through each stage, the applied temperatures and the thermoelectric properties of the semiconductor materials on the exergetic efficiency. Our main result implies that the electric currents flowing in each stage must necessarily be different with a ratio about 4.3 if the best thermal performance and the highest temperature difference possible between the cold and hot side of the device are pursued. This fact had not been pointed out before for pyramid-styled two stage TEM. The ratio n1/n2 should be about 8.

  2. Study on a high capacity two-stage free piston Stirling cryocooler working around 30 K

    Science.gov (United States)

    Wang, Xiaotao; Zhu, Jian; Chen, Shuai; Dai, Wei; Li, Ke; Pang, Xiaomin; Yu, Guoyao; Luo, Ercang

    2016-12-01

    This paper presents a two-stage high-capacity free-piston Stirling cryocooler driven by a linear compressor to meet the requirement of the high temperature superconductor (HTS) motor applications. The cryocooler system comprises a single piston linear compressor, a two-stage free piston Stirling cryocooler and a passive oscillator. A single stepped displacer configuration was adopted. A numerical model based on the thermoacoustic theory was used to optimize the system operating and structure parameters. Distributions of pressure wave, phase differences between the pressure wave and the volume flow rate and different energy flows are presented for a better understanding of the system. Some characterizing experimental results are presented. Thus far, the cryocooler has reached a lowest cold-head temperature of 27.6 K and achieved a cooling power of 78 W at 40 K with an input electric power of 3.2 kW, which indicates a relative Carnot efficiency of 14.8%. When the cold-head temperature increased to 77 K, the cooling power reached 284 W with a relative Carnot efficiency of 25.9%. The influences of different parameters such as mean pressure, input electric power and cold-head temperature are also investigated.

  3. Planning an Agricultural Water Resources Management System: A Two-Stage Stochastic Fractional Programming Model

    Directory of Open Access Journals (Sweden)

    Liang Cui

    2015-07-01

    Full Text Available Irrigation water management is crucial for agricultural production and livelihood security in many regions and countries throughout the world. In this study, a two-stage stochastic fractional programming (TSFP method is developed for planning an agricultural water resources management system under uncertainty. TSFP can provide an effective linkage between conflicting economic benefits and the associated penalties; it can also balance conflicting objectives and maximize the system marginal benefit with per unit of input under uncertainty. The developed TSFP method is applied to a real case of agricultural water resources management of the Zhangweinan River Basin China, which is one of the main food and cotton producing regions in north China and faces serious water shortage. The results demonstrate that the TSFP model is advantageous in balancing conflicting objectives and reflecting complicated relationships among multiple system factors. Results also indicate that, under the optimized irrigation target, the optimized water allocation rate of Minyou Channel and Zhangnan Channel are 57.3% and 42.7%, respectively, which adapts the changes in the actual agricultural water resources management problem. Compared with the inexact two-stage water management (ITSP method, TSFP could more effectively address the sustainable water management problem, provide more information regarding tradeoffs between multiple input factors and system benefits, and help the water managers maintain sustainable water resources development of the Zhangweinan River Basin.

  4. Two-Stage Single-Compartment Models to Evaluate Dissolution in the Lower Intestine.

    Science.gov (United States)

    Markopoulos, Constantinos; Vertzoni, Maria; Symillides, Mira; Kesisoglou, Filippos; Reppas, Christos

    2015-09-01

    The purpose was to propose two-stage single-compartment models for evaluating dissolution characteristics in distal ileum and ascending colon, under conditions simulating the bioavailability and bioequivalence studies in fasted and fed state by using the mini-paddle and the compendial flow-through apparatus (closed-loop mode). Immediate release products of two highly dosed active pharmaceutical ingredients (APIs), sulfasalazine and L-870,810, and one mesalamine colon targeting product were used for evaluating their usefulness. Change of medium composition simulating the conditions in distal ileum (SIFileum ) to a medium simulating the conditions in ascending colon in fasted state and in fed state was achieved by adding an appropriate solution in SIFileum . Data with immediate release products suggest that dissolution in lower intestine is substantially different than in upper intestine and is affected by regional pH differences > type/intensity of fluid convection > differences in concentration of other luminal components. Asacol® (400 mg/tab) was more sensitive to type/intensity of fluid convection. In all the cases, data were in line with available human data. Two-stage single-compartment models may be useful for the evaluation of dissolution in lower intestine. The impact of type/intensity of fluid convection and viscosity of media on luminal performance of other APIs and drug products requires further exploration.

  5. Metamodeling and Optimization of a Blister Copper Two-Stage Production Process

    Science.gov (United States)

    Jarosz, Piotr; Kusiak, Jan; Małecki, Stanisław; Morkisz, Paweł; Oprocha, Piotr; Pietrucha, Wojciech; Sztangret, Łukasz

    2016-06-01

    It is often difficult to estimate parameters for a two-stage production process of blister copper (containing 99.4 wt.% of Cu metal) as well as those for most industrial processes with high accuracy, which leads to problems related to process modeling and control. The first objective of this study was to model flash smelting and converting of Cu matte stages using three different techniques: artificial neural networks, support vector machines, and random forests, which utilized noisy technological data. Subsequently, more advanced models were applied to optimize the entire process (which was the second goal of this research). The obtained optimal solution was a Pareto-optimal one because the process consisted of two stages, making the optimization problem a multi-criteria one. A sequential optimization strategy was employed, which aimed for optimal control parameters consecutively for both stages. The obtained optimal output parameters for the first smelting stage were used as input parameters for the second converting stage. Finally, a search for another optimal set of control parameters for the second stage of a Kennecott-Outokumpu process was performed. The optimization process was modeled using a Monte-Carlo method, and both modeling parameters and computed optimal solutions are discussed.

  6. On bi-criteria two-stage transportation problem: a case study

    Directory of Open Access Journals (Sweden)

    Ahmad MURAD

    2010-01-01

    Full Text Available The study of the optimum distribution of goods between sources and destinations is one of the important topics in projects economics. This importance comes as a result of minimizing the transportation cost, deterioration, time, etc. The classical transportation problem constitutes one of the major areas of application for linear programming. The aim of this problem is to obtain the optimum distribution of goods from different sources to different destinations which minimizes the total transportation cost. From the practical point of view, the transportation problems may differ from the classical form. It may contain one or more objective function, one or more stage to transport, one or more type of commodity with one or more means of transport. The aim of this paper is to construct an optimization model for transportation problem for one of mill-stones companies. The model is formulated as a bi-criteria two-stage transportation problem with a special structure depending on the capacities of suppliers, warehouses and requirements of the destinations. A solution algorithm is introduced to solve this class of bi-criteria two-stage transportation problem to obtain the set of non-dominated extreme points and the efficient solutions accompanied with each one that enables the decision maker to choose the best one. The solution algorithm mainly based on the fruitful application of the methods for treating transportation problems, theory of duality of linear programming and the methods of solving bi-criteria linear programming problems.

  7. An integrated two-stage support vector machine approach to forecast inundation maps during typhoons

    Science.gov (United States)

    Jhong, Bing-Chen; Wang, Jhih-Huang; Lin, Gwo-Fong

    2017-04-01

    During typhoons, accurate forecasts of hourly inundation depths are essential for inundation warning and mitigation. Due to the lack of observed data of inundation maps, sufficient observed data are not available for developing inundation forecasting models. In this paper, the inundation depths, which are simulated and validated by a physically based two-dimensional model (FLO-2D), are used as a database for inundation forecasting. A two-stage inundation forecasting approach based on Support Vector Machine (SVM) is proposed to yield 1- to 6-h lead-time inundation maps during typhoons. In the first stage (point forecasting), the proposed approach not only considers the rainfall intensity and inundation depth as model input but also simultaneously considers cumulative rainfall and forecasted inundation depths. In the second stage (spatial expansion), the geographic information of inundation grids and the inundation forecasts of reference points are used to yield inundation maps. The results clearly indicate that the proposed approach effectively improves the forecasting performance and decreases the negative impact of increasing forecast lead time. Moreover, the proposed approach is capable of providing accurate inundation maps for 1- to 6-h lead times. In conclusion, the proposed two-stage forecasting approach is suitable and useful for improving the inundation forecasting during typhoons, especially for long lead times.

  8. The influence of partial oxidation mechanisms on tar destruction in TwoStage biomass gasification

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Egsgaard, Helge; Stelte, Wolfgang

    2013-01-01

    TwoStage gasification of biomass results in almost tar free producer gas suitable for multiple end-use purposes. In the present study, it is investigated to what extent the partial oxidation process of the pyrolysis gas from the first stage is involved in direct and in-direct tar destruction and ...... tar destruction and a high moisture content of the biomass enhances the decomposition of phenol and inhibits the formation of naphthalene. This enhances tar conversion and gasification in the char-bed, and thus contributes in-directly to the tar destruction.......TwoStage gasification of biomass results in almost tar free producer gas suitable for multiple end-use purposes. In the present study, it is investigated to what extent the partial oxidation process of the pyrolysis gas from the first stage is involved in direct and in-direct tar destruction...... and conversion. The study identifies the following major impact factors regarding tar content in the producer gas: oxidation temperature, excess air ratio and biomass moisture content. In a experimental setup, wood pellets were pyrolyzed and the resulting pyrolysis gas was transferred in a heated partial...

  9. Two stage heterotrophy/photoinduction culture of Scenedesmus incrassatulus: potential for lutein production.

    Science.gov (United States)

    Flórez-Miranda, Liliana; Cañizares-Villanueva, Rosa Olivia; Melchy-Antonio, Orlando; Jerónimo, Fernando Martínez-; Flores-Ortíz, Cesar Mateo

    2017-09-16

    A biomass production process including two stages, heterotrophy/photoinduction (TSHP), was developed to improve biomass and lutein production by the green microalgae Scenedesmus incrassatulus. To determine the effects of different nitrogen sources (yeast extract and urea) and temperature in the heterotrophic stage, experiments using shake flask cultures with glucose as the carbon source were carried out. The highest biomass productivity and specific pigment concentrations were reached using urea+vitamins (U+V) at 30°C. The first stage of the TSHP process was done in a 6L bioreactor, and the inductions in a 3L airlift photobioreactor. At the end of the heterotrophic stage, S. incrassatulus achieved the maximal biomass concentration, increasing from 7.22gL(-1) to 17.98gL(-1) with an increase in initial glucose concentration from 10.6gL(-1) to 30.3gL(-1). However, the higher initial glucose concentration resulted in a lower specific growth rate (μ) and lower cell yield (Yx/s), possibly due to substrate inhibition. After 24h of photoinduction, lutein content in S. incrassatulus biomass was 7 times higher than that obtained at the end of heterotrophic cultivation, and the lutein productivity was 1.6 times higher compared with autotrophic culture of this microalga. Hence, the two-stage heterotrophy/photoinduction culture is an effective strategy for high cell density and lutein production in S. incrassatulus. Copyright © 2017. Published by Elsevier B.V.

  10. Aerobic and two-stage anaerobic-aerobic sludge digestion with pure oxygen and air aeration.

    Science.gov (United States)

    Zupancic, Gregor D; Ros, Milenko

    2008-01-01

    The degradability of excess activated sludge from a wastewater treatment plant was studied. The objective was establishing the degree of degradation using either air or pure oxygen at different temperatures. Sludge treated with pure oxygen was degraded at temperatures from 22 degrees C to 50 degrees C while samples treated with air were degraded between 32 degrees C and 65 degrees C. Using air, sludge is efficiently degraded at 37 degrees C and at 50-55 degrees C. With oxygen, sludge was most effectively degraded at 38 degrees C or at 25-30 degrees C. Two-stage anaerobic-aerobic processes were studied. The first anaerobic stage was always operated for 5 days HRT, and the second stage involved aeration with pure oxygen and an HRT between 5 and 10 days. Under these conditions, there is 53.5% VSS removal and 55.4% COD degradation at 15 days HRT - 5 days anaerobic, 10 days aerobic. Sludge digested with pure oxygen at 25 degrees C in a batch reactor converted 48% of sludge total Kjeldahl nitrogen to nitrate. Addition of an aerobic stage with pure oxygen aeration to the anaerobic digestion enhances ammonium nitrogen removal. In a two-stage anaerobic-aerobic sludge digestion process within 8 days HRT of the aerobic stage, the removal of ammonium nitrogen was 85%.

  11. Dynamics of installation way for the actuator of a two-stage active vibration-isolator

    Institute of Scientific and Technical Information of China (English)

    HU Li; HUANG Qi-bai; HE Xue-song; YUAN Ji-xuan

    2008-01-01

    We investigated the behaviors of an active control system of two-stage vibration isolation with the actuator installed in parallel with either the upper passive mount or the lower passive isolation mount. We revealed the relationships between the active control force of the actuator and the parameters of the passive isolators by studying the dynamics of two-stage active vibration isolation for the actuator at the foregoing two positions in turn. With the actuator installed beside the upper mount, a small active force can achieve a very good isolating effect when the frequency of the stimulating force is much larger than the natural frequency of the upper mount; a larger active force is required in the low-frequency domain; and the active force equals the stimulating force when the upper mount works within the resonance region, suggesting an approach to reducing wobble and ensuring desirable installation accuracy by increasing the upper-mount stiffness. In either the low or the high frequency region far away from the resonance region, the active force is smaller when the actuator is beside the lower mount than beside the upper mount.

  12. Final Report on Two-Stage Fast Spectrum Fuel Cycle Options

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Won Sik [Purdue Univ., West Lafayette, IN (United States); Lin, C. S. [Purdue Univ., West Lafayette, IN (United States); Hader, J. S. [Purdue Univ., West Lafayette, IN (United States); Park, T. K. [Purdue Univ., West Lafayette, IN (United States); Deng, P. [Purdue Univ., West Lafayette, IN (United States); Yang, G. [Purdue Univ., West Lafayette, IN (United States); Jung, Y. S. [Purdue Univ., West Lafayette, IN (United States); Kim, T. K. [Argonne National Lab. (ANL), Argonne, IL (United States); Stauff, N. E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-30

    This report presents the performance characteristics of two “two-stage” fast spectrum fuel cycle options proposed to enhance uranium resource utilization and to reduce nuclear waste generation. One is a two-stage fast spectrum fuel cycle option of continuous recycle of plutonium (Pu) in a fast reactor (FR) and subsequent burning of minor actinides (MAs) in an accelerator-driven system (ADS). The first stage is a sodium-cooled FR fuel cycle starting with low-enriched uranium (LEU) fuel; at the equilibrium cycle, the FR is operated using the recovered Pu and natural uranium without supporting LEU. Pu and uranium (U) are co-extracted from the discharged fuel and recycled in the first stage, and the recovered MAs are sent to the second stage. The second stage is a sodium-cooled ADS in which MAs are burned in an inert matrix fuel form. The discharged fuel of ADS is reprocessed, and all the recovered heavy metals (HMs) are recycled into the ADS. The other is a two-stage FR/ADS fuel cycle option with MA targets loaded in the FR. The recovered MAs are not directly sent to ADS, but partially incinerated in the FR in order to reduce the amount of MAs to be sent to the ADS. This is a heterogeneous recycling option of transuranic (TRU) elements

  13. Hydrogen and methane production from household solid waste in the two-stage fermentation process

    DEFF Research Database (Denmark)

    Lui, D.; Liu, D.; Zeng, Raymond Jianxiong

    2006-01-01

    A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H-2/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH4/g VS....... Furthermore, this study also provided direct evidence in the dynamic fermentation process that, hydrogen production increase was reflected by acetate to butyrate ratio increase in liquid phase. (c) 2006 Elsevier Ltd. All rights reserved.......A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H-2/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH4/g VS...... added. This figure was 21% higher than the methane yield from the one-stage process, which was run as control. Sparging of the hydrogen reactor with methane gas resulted in doubling of the hydrogen production. PH was observed as a key factor affecting fermentation pathway in hydrogen production stage...

  14. Two-stage electrodialytic concentration of glyceric acid from fermentation broth.

    Science.gov (United States)

    Habe, Hiroshi; Shimada, Yuko; Fukuoka, Tokuma; Kitamoto, Dai; Itagaki, Masayuki; Watanabe, Kunihiko; Yanagishita, Hiroshi; Sakaki, Keiji

    2010-12-01

    The aim of this research was the application of a two-stage electrodialysis (ED) method for glyceric acid (GA) recovery from fermentation broth. First, by desalting ED, glycerate solutions (counterpart is Na+) were concentrated using ion-exchange membranes, and the glycerate recovery and energy consumption became more efficient with increasing the initial glycerate concentration (30 to 130 g/l). Second, by water-splitting ED, the concentrated glycerate was electroconverted to GA using bipolar membranes. Using a culture broth of Acetobacter tropicalis containing 68.6 g/l of D-glycerate, a final D-GA concentration of 116 g/l was obtained following the two-stage ED process. The total energy consumption for the D-glycerate concentration and its electroconversion to D-GA was approximately 0.92 kWh per 1 kg of D-GA. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. Occurrence of two-stage hardening in C-Mn steel wire rods containing pearlitic microstructure

    Science.gov (United States)

    Singh, Balbir; Sahoo, Gadadhar; Saxena, Atul

    2016-09-01

    The 8 and 10 mm diameter wire rods intended for use as concrete reinforcement were produced/ hot rolled from C-Mn steel chemistry containing various elements within the range of C:0.55-0.65, Mn:0.85-1.50, Si:0.05-0.09, S:0.04 max, P:0.04 max and N:0.006 max wt%. Depending upon the C and Mn contents the product attained pearlitic microstructure in the range of 85-93% with balance amount of polygonal ferrite transformed at prior austenite grain boundaries. The pearlitic microstructure in the wire rods helped in achieving yield strength, tensile strength, total elongation and reduction in area values within the range of 422-515 MPa, 790-950 MPa, 22-15% and 45-35%, respectively. On analyzing the tensile results it was revealed that the material experienced hardening in two stages separable by a knee strain value of about 0.05. The occurrence of two stage hardening thus in the steel with hardening coefficients of 0.26 and 0.09 could be demonstrated with the help of derived relationships existed between flow stress and the strain.

  16. Rules and mechanisms for efficient two-stage learning in neural circuits

    Science.gov (United States)

    Teşileanu, Tiberiu; Ölveczky, Bence; Balasubramanian, Vijay

    2017-01-01

    Trial-and-error learning requires evaluating variable actions and reinforcing successful variants. In songbirds, vocal exploration is induced by LMAN, the output of a basal ganglia-related circuit that also contributes a corrective bias to the vocal output. This bias is gradually consolidated in RA, a motor cortex analogue downstream of LMAN. We develop a new model of such two-stage learning. Using stochastic gradient descent, we derive how the activity in ‘tutor’ circuits (e.g., LMAN) should match plasticity mechanisms in ‘student’ circuits (e.g., RA) to achieve efficient learning. We further describe a reinforcement learning framework through which the tutor can build its teaching signal. We show that mismatches between the tutor signal and the plasticity mechanism can impair learning. Applied to birdsong, our results predict the temporal structure of the corrective bias from LMAN given a plasticity rule in RA. Our framework can be applied predictively to other paired brain areas showing two-stage learning. DOI: http://dx.doi.org/10.7554/eLife.20944.001 PMID:28374674

  17. Two-stage earth-to-orbit vehicles with dual-fuel propulsion in the Orbiter

    Science.gov (United States)

    Martin, J. A.

    1982-01-01

    Earth-to-orbit vehicle studies of future replacements for the Space Shuttle are needed to guide technology development. Previous studies that have examined single-stage vehicles have shown advantages for dual-fuel propulsion. Previous two-stage system studies have assumed all-hydrogen fuel for the Orbiters. The present study examined dual-fuel Orbiters and found that the system dry mass could be reduced with this concept. The possibility of staging the booster at a staging velocity low enough to allow coast-back to the launch site is shown to be beneficial, particularly in combination with a dual-fuel Orbiter. An engine evaluation indicated the same ranking of engines as did a previous single-stage study. Propane and RP-1 fuels result in lower vehicle dry mass than methane, and staged-combustion engines are preferred over gas-generator engines. The sensitivity to the engine selection is less for two-stage systems than for single-stage systems.

  18. Two-stage effects of awareness cascade on epidemic spreading in multiplex networks

    Science.gov (United States)

    Guo, Quantong; Jiang, Xin; Lei, Yanjun; Li, Meng; Ma, Yifang; Zheng, Zhiming

    2015-01-01

    Human awareness plays an important role in the spread of infectious diseases and the control of propagation patterns. The dynamic process with human awareness is called awareness cascade, during which individuals exhibit herd-like behavior because they are making decisions based on the actions of other individuals [Borge-Holthoefer et al., J. Complex Networks 1, 3 (2013), 10.1093/comnet/cnt006]. In this paper, to investigate the epidemic spreading with awareness cascade, we propose a local awareness controlled contagion spreading model on multiplex networks. By theoretical analysis using a microscopic Markov chain approach and numerical simulations, we find the emergence of an abrupt transition of epidemic threshold βc with the local awareness ratio α approximating 0.5 , which induces two-stage effects on epidemic threshold and the final epidemic size. These findings indicate that the increase of α can accelerate the outbreak of epidemics. Furthermore, a simple 1D lattice model is investigated to illustrate the two-stage-like sharp transition at αc≈0.5 . The results can give us a better understanding of why some epidemics cannot break out in reality and also provide a potential access to suppressing and controlling the awareness cascading systems.

  19. Development of a Two-Stage Microalgae Dewatering Process – A Life Cycle Assessment Approach

    Science.gov (United States)

    Soomro, Rizwan R.; Zeng, Xianhai; Lu, Yinghua; Lin, Lu; Danquah, Michael K.

    2016-01-01

    Even though microalgal biomass is leading the third generation biofuel research, significant effort is required to establish an economically viable commercial-scale microalgal biofuel production system. Whilst a significant amount of work has been reported on large-scale cultivation of microalgae using photo-bioreactors and pond systems, research focus on establishing high performance downstream dewatering operations for large-scale processing under optimal economy is limited. The enormous amount of energy and associated cost required for dewatering large-volume microalgal cultures has been the primary hindrance to the development of the needed biomass quantity for industrial-scale microalgal biofuels production. The extremely dilute nature of large-volume microalgal suspension and the small size of microalgae cells in suspension create a significant processing cost during dewatering and this has raised major concerns towards the economic success of commercial-scale microalgal biofuel production as an alternative to conventional petroleum fuels. This article reports an effective framework to assess the performance of different dewatering technologies as the basis to establish an effective two-stage dewatering system. Bioflocculation coupled with tangential flow filtration (TFF) emerged a promising technique with total energy input of 0.041 kWh, 0.05 kg CO2 emissions and a cost of $ 0.0043 for producing 1 kg of microalgae biomass. A streamlined process for operational analysis of two-stage microalgae dewatering technique, encompassing energy input, carbon dioxide emission, and process cost, is presented. PMID:26904075

  20. Two-stage image segmentation based on edge and region information

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A two-stage method for image segmentation based on edge and region information is proposed. Different deformation schemes are used at two stages for segmenting the object correctly in image plane. At the first stage, the contour of the model is divided into several segments hierarchically that deform respectively using affine transformation. After the contour is deformed to the approximate boundary of object, a fine match mechanism using statistical information of local region to redefine the external energy of the model is used to make the contour fit the object's boundary exactly. The algorithm is effective, as the hierarchical segmental deformation makes use of the globe and local information of the image, the affine transformation keeps the consistency of the model, and the reformative approaches of computing the internal energy and external energy are proposed to reduce the algorithm complexity. The adaptive method of defining the search area at the second stage makes the model converge quickly. The experimental results indicate that the proposed model is effective and robust to local minima and able to search for concave objects.

  1. Waste-gasification efficiency of a two-stage fluidized-bed gasification system.

    Science.gov (United States)

    Liu, Zhen-Shu; Lin, Chiou-Liang; Chang, Tsung-Jen; Weng, Wang-Chang

    2016-02-01

    This study employed a two-stage fluidized-bed gasifier as a gasification reactor and two additives (CaO and activated carbon) as the Stage-II bed material to investigate the effects of the operating temperature (700°C, 800°C, and 900°C) on the syngas composition, total gas yield, and gas-heating value during simulated waste gasification. The results showed that when the operating temperature increased from 700 to 900°C, the molar percentage of H2 in the syngas produced by the two-stage gasification process increased from 19.4 to 29.7mol% and that the total gas yield and gas-heating value also increased. When CaO was used as the additive, the molar percentage of CO2 in the syngas decreased, and the molar percentage of H2 increased. When activated carbon was used, the molar percentage of CH4 in the syngas increased, and the total gas yield and gas-heating value increased. Overall, CaO had better effects on the production of H2, whereas activated carbon clearly enhanced the total gas yield and gas-heating value. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  2. Two-stage numerical simulation for temperature profile in furnace of tangentially fired pulverized coal boiler

    Institute of Scientific and Technical Information of China (English)

    ZHOU Nai-jun; XU Qiong-hui; ZHOU Ping

    2005-01-01

    Considering the fact that the temperature distribution in furnace of a tangential fired pulverized coal boiler is difficult to be measured and monitored, two-stage numerical simulation method was put forward. First, multi-field coupling simulation in typical work conditions was carried out off-line with the software CFX-4.3, and then the expression of temperature profile varying with operating parameter was obtained. According to real-time operating parameters, the temperature at arbitrary point of the furnace can be calculated by using this expression. Thus the temperature profile can be shown on-line and monitoring for combustion state in the furnace is realized. The simul-ation model was checked by the parameters measured in an operating boiler, DG130-9.8/540. The maximum of relative error is less than 12% and the absolute error is less than 120 ℃, which shows that the proposed two-stage simulation method is reliable and able to satisfy the requirement of industrial application.

  3. A low-voltage sense amplifier with two-stage operational amplifier clamping for flash memory

    Science.gov (United States)

    Guo, Jiarong

    2017-04-01

    A low-voltage sense amplifier with reference current generator utilizing two-stage operational amplifier clamp structure for flash memory is presented in this paper, capable of operating with minimum supply voltage at 1 V. A new reference current generation circuit composed of a reference cell and a two-stage operational amplifier clamping the drain pole of the reference cell is used to generate the reference current, which avoids the threshold limitation caused by current mirror transistor in the traditional sense amplifier. A novel reference voltage generation circuit using dummy bit-line structure without pull-down current is also adopted, which not only improves the sense window enhancing read precision but also saves power consumption. The sense amplifier was implemented in a flash realized in 90 nm flash technology. Experimental results show the access time is 14.7 ns with power supply of 1.2 V and slow corner at 125 °C. Project supported by the National Natural Science Fundation of China (No. 61376028).

  4. Two-stage high temperature sludge gasification using the waste heat from hot blast furnace slags.

    Science.gov (United States)

    Sun, Yongqi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

    2015-12-01

    Nowadays, disposal of sewage sludge from wastewater treatment plants and recovery of waste heat from steel industry, become two important environmental issues and to integrate these two problems, a two-stage high temperature sludge gasification approach was investigated using the waste heat in hot slags herein. The whole process was divided into two stages, i.e., the low temperature sludge pyrolysis at ⩽ 900°C in argon agent and the high temperature char gasification at ⩾ 900°C in CO2 agent, during which the heat required was supplied by hot slags in different temperature ranges. Both the thermodynamic and kinetic mechanisms were identified and it was indicated that an Avrami-Erofeev model could best interpret the stage of char gasification. Furthermore, a schematic concept of this strategy was portrayed, based on which the potential CO yield and CO2 emission reduction achieved in China could be ∼1.92∗10(9)m(3) and 1.93∗10(6)t, respectively.

  5. A two-stage broadcast message propagation model in social networks

    Science.gov (United States)

    Wang, Dan; Cheng, Shun-Jun

    2016-11-01

    Message propagation in social networks is becoming a popular topic in complex networks. One of the message types in social networks is called broadcast message. It refers to a type of message which has a unique and unknown destination for the publisher, such as 'lost and found'. Its propagation always has two stages. Due to this feature, rumor propagation model and epidemic propagation model have difficulty in describing this message's propagation accurately. In this paper, an improved two-stage susceptible-infected-removed model is proposed. We come up with the concept of the first forwarding probability and the second forwarding probability. Another part of our work is figuring out the influence to the successful message transmission chance in each level resulting from multiple reasons, including the topology of the network, the receiving probability, the first stage forwarding probability, the second stage forwarding probability as well as the length of the shortest path between the publisher and the relevant destination. The proposed model has been simulated on real networks and the results proved the model's effectiveness.

  6. A two-stage method to determine optimal product sampling considering dynamic potential market.

    Science.gov (United States)

    Hu, Zhineng; Lu, Wei; Han, Bing

    2015-01-01

    This paper develops an optimization model for the diffusion effects of free samples under dynamic changes in potential market based on the characteristics of independent product and presents a two-stage method to figure out the sampling level. The impact analysis of the key factors on the sampling level shows that the increase of the external coefficient or internal coefficient has a negative influence on the sampling level. And the changing rate of the potential market has no significant influence on the sampling level whereas the repeat purchase has a positive one. Using logistic analysis and regression analysis, the global sensitivity analysis gives a whole analysis of the interaction of all parameters, which provides a two-stage method to estimate the impact of the relevant parameters in the case of inaccuracy of the parameters and to be able to construct a 95% confidence interval for the predicted sampling level. Finally, the paper provides the operational steps to improve the accuracy of the parameter estimation and an innovational way to estimate the sampling level.

  7. Selective capsulotomies of the expanded breast as a remodelling method in two-stage breast reconstruction.

    Science.gov (United States)

    Grimaldi, Luca; Campana, Matteo; Brandi, Cesare; Nisi, Giuseppe; Brafa, Anna; Calabrò, Massimiliano; D'Aniello, Carlo

    2013-06-01

    The two-stage breast reconstruction with tissue expander and prosthesis is nowadays a common method for achieving a satisfactory appearance in selected patients who had a mastectomy, but its most common aesthetic drawback is represented by an excessive volumetric increment of the superior half of the reconstructed breast, with a convexity of the profile in that area. A possible solution to limit this effect, and to fulfil the inferior pole, may be obtained by reducing the inferior tissue resistance by means of capsulotomies. This study reports the effects of various types of capsulotomies, performed in 72 patients after removal of the mammary expander, with the aim of emphasising the convexity of the inferior mammary aspect in the expanded breast. According to each kind of desired modification, possible solutions are described. On the basis of subjective and objective evaluations, an overall high degree of satisfaction has been evidenced. The described selective capsulotomies, when properly carried out, may significantly improve the aesthetic results in two-stage reconstructed breasts, with no additional scars, with minimal risks, and with little lengthening of the surgical time.

  8. The Design and Production of a Procedure Training Aid Using the Procedure Learning Format and the Computer Automated Page Layout (PLA) Routine. Technical Note 12-83.

    Science.gov (United States)

    Terrell, William R.; And Others

    This report describes a field application of the Computer Automated Page Layout (PLA) system to the development of a procedure training aid for the SH-3D/H Helicopter, as part of the Training Analysis and Evaluation Group's (TAEG) ongoing development effort to provide tools for the design and publication of technical training aids in a format…

  9. Design of an X-band accelerating structure using a newly developed structural optimization procedure

    Science.gov (United States)

    Huang, Xiaoxia; Fang, Wencheng; Gu, Qiang; Zhao, Zhentang

    2017-05-01

    An X-band high gradient accelerating structure is a challenging technology for implementation in advanced electron linear accelerator facilities. The present work discusses the design of an X-band accelerating structure for dedicated application to a compact hard X-ray free electron laser facility at the Shanghai Institute of Applied Physics, and numerous design optimizations are conducted with consideration for radio frequency (RF) breakdown, RF efficiency, short-range wakefields, and dipole/quadrupole field modes, to ensure good beam quality and a high accelerating gradient. The designed X-band accelerating structure is a constant gradient structure with a 4π/5 operating mode and input and output dual-feed couplers in a racetrack shape. The design process employs a newly developed effective optimization procedure for optimization of the X-band accelerating structure. In addition, the specific design of couplers providing high beam quality by eliminating dipole field components and reducing quadrupole field components is discussed in detail.

  10. Rapid Two-stage Versus One-stage Surgical Repair of Interrupted Aortic Arch with Ventricular Septal Defect in Neonates

    Directory of Open Access Journals (Sweden)

    Meng-Lin Lee

    2008-11-01

    Conclusion: The outcome of rapid two-stage repair is comparable to that of one-stage repair. Rapid two-stage repair has the advantages of significantly shorter cardiopulmonary bypass duration and AXC time, and avoids deep hypothermic circulatory arrest. LVOTO remains an unresolved issue, and postoperative aortic arch restenosis can be dilated effectively by percutaneous balloon angioplasty.

  11. Two-Stage Nerve Graft in Severe Scar: A Time-Course Study in a Rat Model

    Directory of Open Access Journals (Sweden)

    Shayan Zadegan

    2015-04-01

    According to the EPT and WRL, the two-stage nerve graft showed significant improvement (P=0.020 and P =0.017 respectively. The TOA showed no significant difference between the two groups. The total vascular index was significantly higher in the two-stage nerve graft group (P

  12. A general U-block model-based design procedure for nonlinear polynomial control systems

    Science.gov (United States)

    Zhu, Q. M.; Zhao, D. Y.; Zhang, Jianhua

    2016-10-01

    The proposition of U-model concept (in terms of 'providing concise and applicable solutions for complex problems') and a corresponding basic U-control design algorithm was originated in the first author's PhD thesis. The term of U-model appeared (not rigorously defined) for the first time in the first author's other journal paper, which established a framework for using linear polynomial control system design approaches to design nonlinear polynomial control systems (in brief, linear polynomial approaches → nonlinear polynomial plants). This paper represents the next milestone work - using linear state-space approaches to design nonlinear polynomial control systems (in brief, linear state-space approaches → nonlinear polynomial plants). The overall aim of the study is to establish a framework, defined as the U-block model, which provides a generic prototype for using linear state-space-based approaches to design the control systems with smooth nonlinear plants/processes described by polynomial models. For analysing the feasibility and effectiveness, sliding mode control design approach is selected as an exemplary case study. Numerical simulation studies provide a user-friendly step-by-step procedure for the readers/users with interest in their ad hoc applications. In formality, this is the first paper to present the U-model-oriented control system design in a formal way and to study the associated properties and theorems. The previous publications, in the main, have been algorithm-based studies and simulation demonstrations. In some sense, this paper can be treated as a landmark for the U-model-based research from intuitive/heuristic stage to rigour/formal/comprehensive studies.

  13. Defining System Requirements: a critical assessment of the Niam conceptual design procedure

    Directory of Open Access Journals (Sweden)

    Peta Darke

    1995-05-01

    Full Text Available Requirements definition is a fundamental activity within information systems development. Social and organisational issues are at the centre of many of the problems experienced during the development and implementation of information systems, and these need to be explored during requirements definition. The NIAM Conceptual Schema Design Procedure (CSDP is a method for identifying and describing information requirements using fact types. This paper discusses some limitations of the information requirements definition step of the CSDP which result from its lack of focus on the socio-organisational dimension of information systems development. Four different approaches to exploring the socio-organisational contexts of systems are discussed. It is proposed that one of these, viewpoint development, be incorporated into the NIAM CSDP to provide a means of exploring and understanding a system's socio organisational context and to ensure that contextual information is a major input to the requirements definition process. This results in an enhanced design procedure. Future and current research areas are identified.

  14. Reconstruction of an external hemipelvectomy defect with a two-stage fillet of leg-free flap.

    Science.gov (United States)

    Boehmler, James H; Francis, Stacey H; Grawe, Roxanne K; Mayerson, Joel L

    2010-05-01

    The defect created by external hemipelvectomy for bone and soft tissue tumor resection is a challenge to reconstruct because of the exposure of bone, neurovascular structures, and peritoneal contents, particularly in the setting of previous radiotherapy. In a nonsalvageable limb with extensive tumor involvement and radiation damage, a free fillet of leg flap can be used to provide the necessary large volume of tissue for reconstruction without donor site morbidity. Because of the lengthy operative time for the hemipelvectomy procedure, the fillet of leg flap may be subject to long ischemia time and a subsequently compromised outcome. A two-stage fillet of leg flap for a hemipelvectomy defect was performed with two goals: to decrease ischemia time and to allow the necessary resuscitation of the patient between operative stages. Stage one was dissection of a lower fillet of leg flap, transfer and anastomosis to the contralateral femoral vessels, and temporary inset in the groin. The patient and flap were observed in the intensive care unit for several days. The patient returned to the operating room 3 days later for staged external hemipelvectomy and inset of the viable fillet of leg flap. Throughout follow-up, the reconstructive results and functional outcome were excellent.

  15. Sulfur removal in advanced two-stage fluidized-bed combustion. [Quarterly] technical report, December 1, 1993--February 28, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Hill, A.H.; Wangerow, J.R.; Rue, D.M. [Inst. of Gas Technology, Chicago, IL (United States)

    1994-06-01

    The objective of this study is to obtain data on the rates of reaction between, hydrogen sulfide (H{sub 2}S) and uncalcined calcium-based sorbents under operating conditions relevant to first stage (carbonizer) of Advanced Two-Stage Pressurized Fluidized-Bed Combustors (PFBC). In these systems the CO{sub 2} partial pressure in the first stage generally exceeds the equilibrium value for calcium carbonate decomposition. Therefore, removal of sulfur compounds takes place through the reaction between H{sub 2}S and calcium carbonate. To achieve this objective the rates of reaction between hydrogen sulfide and uncalcined calcium-based sorbents will be determined by conducting tests in pressurized thermogravimetric analyzer (TGA) and high-pressure/high-temperature fluidized-bed reactor (HPTR) units. The effects of sorbent type, sorbent particle size, reactor temperature and pressure, and CO{sub 2} and H{sub 2}S partial pressures on the sulfidation reaction rate will be determined. During this quarter, the high-pressure thermogravimetric analyzer (HPTGA) unit was installed and the shakedown process was completed. Several tests were conducted in the HPTGA unit to establish the operating procedure and the repeatability of the experimental results. Sulfidation by conducting the baseline sulfidation tests. The results are currently being analyzed.

  16. FunSAV: predicting the functional effect of single amino acid variants using a two-stage random forest model.

    Directory of Open Access Journals (Sweden)

    Mingjun Wang

    Full Text Available Single amino acid variants (SAVs are the most abundant form of known genetic variations associated with human disease. Successful prediction of the functional impact of SAVs from sequences can thus lead to an improved understanding of the underlying mechanisms of why a SAV may be associated with certain disease. In this work, we constructed a high-quality structural dataset that contained 679 high-quality protein structures with 2,048 SAVs by collecting the human genetic variant data from multiple resources and dividing them into two categories, i.e., disease-associated and neutral variants. We built a two-stage random forest (RF model, termed as FunSAV, to predict the functional effect of SAVs by combining sequence, structure and residue-contact network features with other additional features that were not explored in previous studies. Importantly, a two-step feature selection procedure was proposed to select the most important and informative features that contribute to the prediction of disease association of SAVs. In cross-validation experiments on the benchmark dataset, FunSAV achieved a good prediction performance with the area under the curve (AUC of 0.882, which is competitive with and in some cases better than other existing tools including SIFT, SNAP, Polyphen2, PANTHER, nsSNPAnalyzer and PhD-SNP. The sourcecodes of FunSAV and the datasets can be downloaded at http://sunflower.kuicr.kyoto-u.ac.jp/sjn/FunSAV.

  17. The Assessment Supplement: A Faculty-Designed Addition to NCC's Manual, "Concepts & Procedures for Academic Assessment." First Edition.

    Science.gov (United States)

    Nassau Community Coll., Garden City, NY.

    This document is the first in a series of annual, faculty-designed supplements to Nassau Community College's (NCC's) (New York) manual, "Concepts & Procedures for Academic Assessment." The supplements are intended to provide faculty a forum through which they can communicate assessment designs and the impacts of those designs on…

  18. Two-stage atlas subset selection in multi-atlas based image segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Tingting, E-mail: tingtingzhao@mednet.ucla.edu; Ruan, Dan, E-mail: druan@mednet.ucla.edu [The Department of Radiation Oncology, University of California, Los Angeles, California 90095 (United States)

    2015-06-15

    Purpose: Fast growing access to large databases and cloud stored data presents a unique opportunity for multi-atlas based image segmentation and also presents challenges in heterogeneous atlas quality and computation burden. This work aims to develop a novel two-stage method tailored to the special needs in the face of large atlas collection with varied quality, so that high-accuracy segmentation can be achieved with low computational cost. Methods: An atlas subset selection scheme is proposed to substitute a significant portion of the computationally expensive full-fledged registration in the conventional scheme with a low-cost alternative. More specifically, the authors introduce a two-stage atlas subset selection method. In the first stage, an augmented subset is obtained based on a low-cost registration configuration and a preliminary relevance metric; in the second stage, the subset is further narrowed down to a fusion set of desired size, based on full-fledged registration and a refined relevance metric. An inference model is developed to characterize the relationship between the preliminary and refined relevance metrics, and a proper augmented subset size is derived to ensure that the desired atlases survive the preliminary selection with high probability. Results: The performance of the proposed scheme has been assessed with cross validation based on two clinical datasets consisting of manually segmented prostate and brain magnetic resonance images, respectively. The proposed scheme demonstrates comparable end-to-end segmentation performance as the conventional single-stage selection method, but with significant computation reduction. Compared with the alternative computation reduction method, their scheme improves the mean and medium Dice similarity coefficient value from (0.74, 0.78) to (0.83, 0.85) and from (0.82, 0.84) to (0.95, 0.95) for prostate and corpus callosum segmentation, respectively, with statistical significance. Conclusions: The authors

  19. Input torque balancing using a cam-based centrifugal pendulum: design procedure and example

    Science.gov (United States)

    Demeulenaere, Bram; Spaepen, Pieter; De Schutter, Joris

    2005-05-01

    Input torque balancing is a well-known way to reduce drive speed fluctuations in high-speed machinery and combustion engines. This paper introduces a cam-based centrifugal pendulum (CBCP) and a design procedure for it which results in quasi-perfect balancing of inertial torques for any drive speed. The CBCP combines the centrifugal pendulum vibration absorber, well-known in mechanical vibration literature, with a torque balancing principle well-known in mechanism literature, that is, the use of cams to generate arbitrary torques. For given design parameters (such as the link lengths and link inertial parameters), the cam design is governed by a nonlinear, second-order, explicit differential equation. This differential equation is numerically solved by reformulating it as a nonlinear least-squares problem. The design parameters themselves are determined by means of an optimization problem, the goal of which is to minimize the (constant) equivalent inertia of the combined system, consisting of the original mechanism to be balanced and the CBCP. Application of the CBCP to torque balance a high-speed, purely inertial cam-follower mechanism, driving the sley of a weaving loom, shows that the optimization results in a compact and technologically feasible mechanism.

  20. Numerical analysis of flow interaction of turbine system in two-stage turbocharger of internal combustion engine

    Science.gov (United States)

    Liu, Y. B.; Zhuge, W. L.; Zhang, Y. J.; Zhang, S. Y.

    2016-05-01

    To reach the goal of energy conservation and emission reduction, high intake pressure is needed to meet the demand of high power density and high EGR rate for internal combustion engine. Present power density of diesel engine has reached 90KW/L and intake pressure ratio needed is over 5. Two-stage turbocharging system is an effective way to realize high compression ratio. Because turbocharging system compression work derives from exhaust gas energy. Efficiency of exhaust gas energy influenced by design and matching of turbine system is important to performance of high supercharging engine. Conventional turbine system is assembled by single-stage turbocharger turbines and turbine matching is based on turbine MAP measured on test rig. Flow between turbine system is assumed uniform and value of outlet physical quantities of turbine are regarded as the same as ambient value. However, there are three-dimension flow field distortion and outlet physical quantities value change which will influence performance of turbine system as were demonstrated by some studies. For engine equipped with two-stage turbocharging system, optimization of turbine system design will increase efficiency of exhaust gas energy and thereby increase engine power density. However flow interaction of turbine system will change flow in turbine and influence turbine performance. To recognize the interaction characteristics between high pressure turbine and low pressure turbine, flow in turbine system is modeled and simulated numerically. The calculation results suggested that static pressure field at inlet to low pressure turbine increases back pressure of high pressure turbine, however efficiency of high pressure turbine changes little; distorted velocity field at outlet to high pressure turbine results in swirl at inlet to low pressure turbine. Clockwise swirl results in large negative angle of attack at inlet to rotor which causes flow loss in turbine impeller passages and decreases turbine

  1. Two-stage-six-objective calibration of a hydrodynamic-based sediment transport model for the Mekong Delta

    Science.gov (United States)

    Viet Dung, Nguyen; Van Manh, Nguyen; Merz, Bruno; Apel, Heiko

    2014-05-01

    formulate a two-stage calibration by firstly estimating parameters for the HD module to fit the three objective functions and then estimating the parameters for the AD module the fit the remaining three objective functions. We developed a wrapper code implementing the parallel version of NSGA II, controlling the whole calibration process of both stages. This reduces the computational time significantly and facilitates the calibration in due time. The calibration results imply that the proposed two-stage-six-objective calibration procedure provides meaningful parameter sets fulfilling the different objectives in a Pareto sense, even for such a large scale 2D quasi hydrodynamic-based sediment transport model within a highly complex study domain like the Mekong Delta.

  2. Hardware Design and Implementation of a Wavelet De-Noising Procedure for Medical Signal Preprocessing

    Directory of Open Access Journals (Sweden)

    Szi-Wen Chen

    2015-10-01

    Full Text Available In this paper, a discrete wavelet transform (DWT based de-noising with its applications into the noise reduction for medical signal preprocessing is introduced. This work focuses on the hardware realization of a real-time wavelet de-noising procedure. The proposed de-noising circuit mainly consists of three modules: a DWT, a thresholding, and an inverse DWT (IDWT modular circuits. We also proposed a novel adaptive thresholding scheme and incorporated it into our wavelet de-noising procedure. Performance was then evaluated on both the architectural designs of the software and. In addition, the de-noising circuit was also implemented by downloading the Verilog codes to a field programmable gate array (FPGA based platform so that its ability in noise reduction may be further validated in actual practice. Simulation experiment results produced by applying a set of simulated noise-contaminated electrocardiogram (ECG signals into the de-noising circuit showed that the circuit could not only desirably meet the requirement of real-time processing, but also achieve satisfactory performance for noise reduction, while the sharp features of the ECG signals can be well preserved. The proposed de-noising circuit was further synthesized using the Synopsys Design Compiler with an Artisan Taiwan Semiconductor Manufacturing Company (TSMC, Hsinchu, Taiwan 40 nm standard cell library. The integrated circuit (IC synthesis simulation results showed that the proposed design can achieve a clock frequency of 200 MHz and the power consumption was only 17.4 mW, when operated at 200 MHz.

  3. Two-stage dilute-acid and organic-solvent lignocellulosic pretreatment for enhanced bioprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Brodeur, G.; Telotte, J.; Stickel, J. J.; Ramakrishnan, S.

    2016-11-01

    A two stage pretreatment approach for biomass is developed in the current work in which dilute acid (DA) pretreatment is followed by a solvent based pretreatment (N-methyl morpholine N oxide -- NMMO). When the combined pretreatment (DAWNT) is applied to sugarcane bagasse and corn stover, the rates of hydrolysis and overall yields (>90%) are seen to dramatically improve and under certain conditions 48 h can be taken off the time of hydrolysis with the additional NMMO step to reach similar conversions. DAWNT shows a 2-fold increase in characteristic rates and also fractionates different components of biomass -- DA treatment removes the hemicellulose while the remaining cellulose is broken down by enzymatic hydrolysis after NMMO treatment to simple sugars. The remaining residual solid is high purity lignin. Future work will focus on developing a full scale economic analysis of DAWNT for use in biomass fractionation.

  4. Reconstruction of Gene Regulatory Networks Based on Two-Stage Bayesian Network Structure Learning Algorithm

    Institute of Scientific and Technical Information of China (English)

    Gui-xia Liu; Wei Feng; Han Wang; Lei Liu; Chun-guang Zhou

    2009-01-01

    In the post-genomic biology era, the reconstruction of gene regulatory networks from microarray gene expression data is very important to understand the underlying biological system, and it has been a challenging task in bioinformatics. The Bayesian network model has been used in reconstructing the gene regulatory network for its advantages, but how to determine the network structure and parameters is still important to be explored. This paper proposes a two-stage structure learning algorithm which integrates immune evolution algorithm to build a Bayesian network .The new algorithm is evaluated with the use of both simulated and yeast cell cycle data. The experimental results indicate that the proposed algorithm can find many of the known real regulatory relationships from literature and predict the others unknown with high validity and accuracy.

  5. The Application of Two-stage Structure Decomposition Technique to the Study of Industrial Carbon Emissions

    Institute of Scientific and Technical Information of China (English)

    Yanqiu HE

    2015-01-01

    The total carbon emissions control is the ultimate goal of carbon emission reduction, while industrial carbon emissions are the basic units of the total carbon emission. On the basis of existing research results, in this paper, a two-stage input-output structure decomposition method is creatively proposed for fully combining the input-output method with the structure decomposition technique. In this study, more comprehensive technical progress indicators were chosen in comparison with the previous studies and included the utilization efficiency of all kinds of intermediate inputs such as energy and non-energy products, and finally were positioned at the factors affecting the carbon emissions of different industries. Through analysis, the affecting rate of each factor on industrial carbon emissions was acquired. Thus, a theory basis and data support is provided for the total carbon emissions control of China from the perspective of industrial emissions.

  6. A two-stage metal valorisation process from electric arc furnace dust (EAFD

    Directory of Open Access Journals (Sweden)

    H. Issa

    2016-04-01

    Full Text Available This paper demonstrates possibility of separate zinc and lead recovery from coal composite pellets, composed of EAFD with other synergetic iron-bearing wastes and by-products (mill scale, pyrite-cinder, magnetite concentrate, through a two-stage process. The results show that in the first, low temp erature stage performed in electro-resistant furnace, removal of lead is enabled due to presence of chlorides in the system. In the second stage, performed at higher temperatures in Direct Current (DC plasma furnace, valorisation of zinc is conducted. Using this process, several final products were obtained, including a higher purity zinc oxide, which, by its properties, corresponds washed Waelz oxide.

  7. A wavelet-based two-stage near-lossless coder.

    Science.gov (United States)

    Yea, Sehoon; Pearlman, William A

    2006-11-01

    In this paper, we present a two-stage near-lossless compression scheme. It belongs to the class of "lossy plus residual coding" and consists of a wavelet-based lossy layer followed by arithmetic coding of the quantized residual to guarantee a given L(infinity) error bound in the pixel domain. We focus on the selection of the optimum bit rate for the lossy layer to achieve the minimum total bit rate. Unlike other similar lossy plus lossless approaches using a wavelet-based lossy layer, the proposed method does not require iteration of decoding and inverse discrete wavelet transform in succession to locate the optimum bit rate. We propose a simple method to estimate the optimal bit rate, with a theoretical justification based on the critical rate argument from the rate-distortion theory and the independence of the residual error.

  8. Two-Stage Over-the-Air (OTA Test Method for LTE MIMO Device Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Ya Jing

    2012-01-01

    Full Text Available With MIMO technology being adopted by the wireless communication standards LTE and HSPA+, MIMO OTA research has attracted wide interest from both industry and academia. Parallel studies are underway in COST2100, CTIA, and 3GPP RAN WG4. The major test challenge for MIMO OTA is how to create a repeatable scenario which accurately reflects the MIMO antenna radiation performance in a realistic wireless propagation environment. Different MIMO OTA methods differ in the way to reproduce a specified MIMO channel model. This paper introduces a novel, flexible, and cost-effective method for measuring MIMO OTA using a two-stage approach. In the first stage, the antenna pattern is measured in an anechoic chamber using a nonintrusive approach, that is without cabled connections or modifying the device. In the second stage, the antenna pattern is convolved with the chosen channel model in a channel emulator to measure throughput using a cabled connection.

  9. Two stages of parafoveal processing during reading: Evidence from a display change detection task.

    Science.gov (United States)

    Angele, Bernhard; Slattery, Timothy J; Rayner, Keith

    2016-08-01

    We used a display change detection paradigm (Slattery, Angele, & Rayner Human Perception and Performance, 37, 1924-1938 2011) to investigate whether display change detection uses orthographic regularity and whether detection is affected by the processing difficulty of the word preceding the boundary that triggers the display change. Subjects were significantly more sensitive to display changes when the change was from a nonwordlike preview than when the change was from a wordlike preview, but the preview benefit effect on the target word was not affected by whether the preview was wordlike or nonwordlike. Additionally, we did not find any influence of preboundary word frequency on display change detection performance. Our results suggest that display change detection and lexical processing do not use the same cognitive mechanisms. We propose that parafoveal processing takes place in two stages: an early, orthography-based, preattentional stage, and a late, attention-dependent lexical access stage.

  10. Enhanced biodiesel production in Neochloris oleoabundans by a semi-continuous process in two stage photobioreactors.

    Science.gov (United States)

    Yoon, Se Young; Hong, Min Eui; Chang, Won Seok; Sim, Sang Jun

    2015-07-01

    Under autotrophic conditions, highly productive biodiesel production was achieved using a semi-continuous culture system in Neochloris oleoabundans. In particular, the flue gas generated by combustion of liquefied natural gas and natural solar radiation were used for cost-effective microalgal culture system. In semi-continuous culture, the greater part (~80%) of the culture volume containing vegetative cells grown under nitrogen-replete conditions in a first photobioreactor (PBR) was directly transferred to a second PBR and cultured sequentially under nitrogen-deplete conditions for accelerating oil accumulation. As a result, in semi-continuous culture, the productivities of biomass and biodiesel in the cells were increased by 58% (growth phase) and 51% (induction phase) compared to the cells in batch culture, respectively. The semi-continuous culture system using two stage photobioreactors is a very efficient strategy to further improve biodiesel production from microalgae under photoautotrophic conditions.

  11. The Sources of Efficiency of the Nigerian Banking Industry: A Two- Stage Approach

    Directory of Open Access Journals (Sweden)

    Frances Obafemi

    2013-11-01

    Full Text Available The paper employed a two-stage Data Envelopment Analysis (DEA approach to examine the sources oftechnical efficiency in the Nigerian banking sub-sector. Using a cross sectionof commercial and merchant banks, the study showed that the Nigerian bankingindustry was not efficient both in the pre-and-post-liberalization era. Thestudy further revealed that market share was the strongest determinant oftechnical efficiency in the Nigerian banking Industry. Thus, appropriatemacroeconomic policy, institutional development and structural reforms mustaccompany financial liberalization to create the stable environment requiredfor it to succeed. Hence, the present bank consolidation and reforms by theCentral Bank of Nigeria, which started with Soludo and continued with Sanusi,are considered necessary, especially in the areas of e banking and reorganizingthe management of banks.

  12. Two-stage triolein breath test differentiates pancreatic insufficiency from other causes of malabsorption

    Energy Technology Data Exchange (ETDEWEB)

    Goff, J.S.

    1982-07-01

    In 24 patients with malabsorption, (/sup 14/C)triolein breath tests were conducted before and together with the administration of pancreatic enzymes (Pancrease, Johnson and Johnson, Skillman, N.J.). Eleven patients with pancreatic insufficiency had a significant rise in peak percent dose per hour /sup 14/CO/sub 2/ excretion after Pancrease, whereas 13 patients with other causes of malabsorption had no increase in /sup 14/CO/sub 2/ excretion (2.61 +/- 0.96 vs. 0.15 +/- 0.45, p less than 0.001). The two-stage (/sup 14/C)triolein breath test appears to be an accurate and simple noninvasive test of fat malabsorption that differentiates steatorrhea secondary to pancreatic insufficiency from other causes of steatorrhea.

  13. Product prioritization in a two-stage food production system with intermediate storage

    DEFF Research Database (Denmark)

    Akkerman, Renzo; van Donk, Dirk Pieter

    2007-01-01

    In the food-processing industry, usually a limited number of storage tanks for intermediate storage is available, which are used for different products. The market sometimes requires extremely short lead times for some products, leading to prioritization of these products, partly through the dedi......In the food-processing industry, usually a limited number of storage tanks for intermediate storage is available, which are used for different products. The market sometimes requires extremely short lead times for some products, leading to prioritization of these products, partly through...... the dedication of a storage tank. This type of situation has hardly been investigated, although planners struggle with it in practice. This paper aims at investigating the fundamental effect of prioritization and dedicated storage in a two-stage production system, for various product mixes. We show...

  14. ADM1-based modeling of methane production from acidified sweet sorghum extractin a two stage process

    DEFF Research Database (Denmark)

    Antonopoulou, Georgia; Gavala, Hariklia N.; Skiadas, Ioannis

    2012-01-01

    The present study focused on the application of the Anaerobic Digestion Model 1 οn the methane production from acidified sorghum extract generated from a hydrogen producing bioreactor in a two-stage anaerobic process. The kinetic parameters for hydrogen and volatile fatty acids consumption were...... estimated through fitting of the model equations to the data obtained from batch experiments. The simulation of the continuous reactor performance at all HRTs tested (20, 15 and 10d) was very satisfactory. Specifically, the largest deviation of the theoretical predictions against the experimental data...... was 12% for the methane production rate at the HRT of 20d while the deviation values for the 15 and 10 d HRT were 1.9% and 1.1%, respectively. The model predictions regarding pH, methane percentage in the gas phase and COD removal were in very good agreement with the experimental data with a deviation...

  15. A Two-Stage Diagnosis Framework for Wind Turbine Gearbox Condition Monitoring

    Directory of Open Access Journals (Sweden)

    Janet M. Twomey

    2013-01-01

    Full Text Available Advances in high performance sensing technologies enable the development of wind turbine condition monitoring system to diagnose and predict the system-wide effects of failure events. This paper presents a vibration-based two stage fault detection framework for failure diagnosis of rotating components in wind turbines. The proposed framework integrates an analytical defect detection method and a graphical verification method together to ensure the diagnosis efficiency and accuracy. The efficacy of the proposed methodology is demonstrated with a case study with the gearbox condition monitoring Round Robin study dataset provided by the National Renewable Energy Laboratory (NREL. The developed methodology successfully picked five faults out of seven in total with accurate severity levels without producing any false alarm in the blind analysis. The case study results indicated that the developed fault detection framework is effective for analyzing gear and bearing faults in wind turbine drive train system based upon system vibration characteristics.

  16. Nitrification and microalgae cultivation for two-stage biological nutrient valorization from source separated urine.

    Science.gov (United States)

    Coppens, Joeri; Lindeboom, Ralph; Muys, Maarten; Coessens, Wout; Alloul, Abbas; Meerbergen, Ken; Lievens, Bart; Clauwaert, Peter; Boon, Nico; Vlaeminck, Siegfried E

    2016-07-01

    Urine contains the majority of nutrients in urban wastewaters and is an ideal nutrient recovery target. In this study, stabilization of real undiluted urine through nitrification and subsequent microalgae cultivation were explored as strategy for biological nutrient recovery. A nitrifying inoculum screening revealed a commercial aquaculture inoculum to have the highest halotolerance. This inoculum was compared with municipal activated sludge for the start-up of two nitrification membrane bioreactors. Complete nitrification of undiluted urine was achieved in both systems at a conductivity of 75mScm(-1) and loading rate above 450mgNL(-1)d(-1). The halotolerant inoculum shortened the start-up time with 54%. Nitrite oxidizers showed faster salt adaptation and Nitrobacter spp. became the dominant nitrite oxidizers. Nitrified urine as growth medium for Arthrospira platensis demonstrated superior growth compared to untreated urine and resulted in a high protein content of 62%. This two-stage strategy is therefore a promising approach for biological nutrient recovery.

  17. A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    Due to the still increasing penetration of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid...... to achieve the power reserve. In this method, the solar irradiance and temperature measurements that have been used in conventional power reserve control schemes to estimate the available PV power are not required, and thereby being a sensorless approach with reduced cost. Experimental tests have been...... support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...

  18. Sensorless Reserved Power Control Strategy for Two-Stage Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    Due to still increasing penetration level of grid-connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A reserved power control, where the active power from the PV panels is reserved during operation, is required for grid...... to achieve the power reserve. In this method, the irradiance measurements that have been used in conventional control schemes to estimate the available PV power are not required, and thereby being a sensorless solution. Simulations and experimental tests have been performed on a 3-kW two-stage single...... support. In this paper, a cost-effective solution to realize the reserved power control for grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control...

  19. Prey-Predator Model with Two-Stage Infection in Prey: Concerning Pest Control

    Directory of Open Access Journals (Sweden)

    Swapan Kumar Nandi

    2015-01-01

    Full Text Available A prey-predator model system is developed; specifically the disease is considered into the prey population. Here the prey population is taken as pest and the predators consume the selected pest. Moreover, we assume that the prey species is infected with a viral disease forming into susceptible and two-stage infected classes, and the early stage of infected prey is more vulnerable to predation by the predator. Also, it is assumed that the later stage of infected pests is not eaten by the predator. Different equilibria of the system are investigated and their stability analysis and Hopf bifurcation of the system around the interior equilibriums are discussed. A modified model has been constructed by considering some alternative source of food for the predator population and the dynamical behavior of the modified model has been investigated. We have demonstrated the analytical results by numerical analysis by taking some simulated set of parameter values.

  20. Lossless and near-lossless digital angiography coding using a two-stage motion compensation approach.

    Science.gov (United States)

    dos Santos, Rafael A P; Scharcanski, Jacob

    2008-07-01

    This paper presents a two-stage motion compensation coding scheme for image sequences in hemodynamics. The first stage of the proposed method implements motion compensation, and the second stage corrects local pixel intensity distortions with a context adaptive linear predictor. The proposed method is robust to the local intensity distortions and the noise that often degrades these image sequences, providing lossless and near-lossless quality. Our experiments with lossless compression of 12bits/pixel studies indicate that, potentially, our approach can perform 3.8%, 2% and 1.6% better than JPEG-2000, JPEG-LS and the method proposed by Scharcanski [1], respectively. The performance tends to improve for near-lossless compression. Therefore, this work presents experimental evidence that for coding image sequences in hemodynamics, an adequate motion compensation scheme can be more efficient than the still-image coding methods often used nowadays.