Numerical simulations of single and multi-staged injection of H2 in a supersonic scramjet combustor

Directory of Open Access Journals (Sweden)

L. Abu-Farah

2014-12-01

Full Text Available Computational fluid dynamics (CFD simulations of a single staged injection of H2 through a central wedge shaped strut and a multi-staged injection through wall injectors are carried out by using Ansys CFX-12 code. Unstructured tetrahedral grids for narrow channel and quarter geometries of the combustor are generated by using ICEM CFD. Steady three-dimensional (3D Reynolds-averaged Navier-stokes (RANS simulations are carried out in the case of no H2 injection and compared with the simulations of single staged pilot and/or main H2 injections and multistage injection. Shear stress transport (SST based on k-ω turbulent model is adopted. Flow field visualization (complex shock waves interactions and static pressure distribution along the wall of the combustor are predicted and compared with the experimental schlieren images and measured wall static pressures for validation. A good agreement is found between the CFD predicted results and the measured data. The narrow and quarter geometries of the combustor give similar results with very small differences. Multi-staged injections of H2 enhance the turbulent H2/air mixing by forming vortices and additional shock waves (bow shocks.

Studying the effect of over-modulation on the output voltage of three-phase single-stage grid-connected boost inverter

Directory of Open Access Journals (Sweden)

A. Abbas Elserougi

2013-09-01

Full Text Available Voltage boosting is very essential issue in renewable-energy fed applications. The classical two-stage power conversion process is typically used to interface the renewable energy sources to the grid. For better efficiency, single-stage inverters are recommended. In this paper, the performance of single-stage three-phase grid-connected boost inverter is investigated when its gain is extended by employing over-modulation technique. Using of over-modulation is compared with the employment of third order harmonic injection. The latter method can increase the inverter gain by 15% without distorting the inverter output voltage. The performance of extended gain grid-connected boost inverter is also tested during normal operation as well as in the presence of grid side disturbances. Simulation and experimental results are satisfactory.

Mathematical modeling of a single stage ultrasonically assisted distillation process.

Science.gov (United States)

Mahdi, Taha; Ahmad, Arshad; Ripin, Adnan; Abdullah, Tuan Amran Tuan; Nasef, Mohamed M; Ali, Mohamad W

2015-05-01

The ability of sonication phenomena in facilitating separation of azeotropic mixtures presents a promising approach for the development of more intensified and efficient distillation systems than conventional ones. To expedite the much-needed development, a mathematical model of the system based on conservation principles, vapor-liquid equilibrium and sonochemistry was developed in this study. The model that was founded on a single stage vapor-liquid equilibrium system and enhanced with ultrasonic waves was coded using MATLAB simulator and validated with experimental data for ethanol-ethyl acetate mixture. The effects of both ultrasonic frequency and intensity on the relative volatility and azeotropic point were examined, and the optimal conditions were obtained using genetic algorithm. The experimental data validated the model with a reasonable accuracy. The results of this study revealed that the azeotropic point of the mixture can be totally eliminated with the right combination of sonication parameters and this can be utilized in facilitating design efforts towards establishing a workable ultrasonically intensified distillation system. Copyright © 2014 Elsevier B.V. All rights reserved.

85,000-GPM, single-stage, single-suction LMFBR intermediate centrifugal pump

International Nuclear Information System (INIS)

Fair, C.E.; Cook, M.E.; Huber, K.A.; Rohde, R.

1983-01-01

The mechanical and hydraulic design features of the 85,000-gpm, single-stage, single-suction pump test article, which is designed to circulate liquid-sodium coolant in the intermediate heat-transport system of a Large-Scale Liquid Metal Fast Breeder Reactor (LS-LMFBR), are described. The design and analytical considerations used to satisfy the pump performance and operability requirements are presented. The validation of pump hydraulic performance using a hydraulic scale-model pump is discussed, as is the featute test for the mechanical-shaft seal system

Methodology of theory of stage-by-stage long-term preparation of sportsmen in single combats

Directory of Open Access Journals (Sweden)

Arziutov G.

2010-04-01

Full Text Available Results over of researches are brought on methodology of theory of stage-by-stage preparation of sportsmen in single combats. The structuralness of theory lies in possibility simple verifications of its substantive provisions, principles and laws. Development of methodology enables to begin creation of map of trainer on the stages of long-term preparation. Laws, conformities to law, principles and rules, must be collected in a map. A map enables the trainers of reserve sport to use its content during all stages of preparation of sportsman.

Experimental Results of the First Two Stages of an Advanced Transonic Core Compressor Under Isolated and Multi-Stage Conditions

Science.gov (United States)

Prahst, Patricia S.; Kulkarni, Sameer; Sohn, Ki H.

2015-01-01

NASA's Environmentally Responsible Aviation (ERA) Program calls for investigation of the technology barriers associated with improved fuel efficiency of large gas turbine engines. Under ERA the task for a High Pressure Ratio Core Technology program calls for a higher overall pressure ratio of 60 to 70. This mean that the HPC would have to almost double in pressure ratio and keep its high level of efficiency. The challenge is how to match the corrected mass flow rate of the front two supersonic high reaction and high corrected tip speed stages with a total pressure ratio of 3.5. NASA and GE teamed to address this challenge by using the initial geometry of an advanced GE compressor design to meet the requirements of the first 2 stages of the very high pressure ratio core compressor. The rig was configured to run as a 2 stage machine, with Strut and IGV, Rotor 1 and Stator 1 run as independent tests which were then followed by adding the second stage. The goal is to fully understand the stage performances under isolated and multi-stage conditions and fully understand any differences and provide a detailed aerodynamic data set for CFD validation. Full use was made of steady and unsteady measurement methods to isolate fluid dynamics loss source mechanisms due to interaction and endwalls. The paper will present the description of the compressor test article, its predicted performance and operability, and the experimental results for both the single stage and two stage configurations. We focus the detailed measurements on 97 and 100 of design speed at 3 vane setting angles.

Single-session versus staged procedures for elective multivessel percutaneous coronary intervention.

Science.gov (United States)

Toyota, Toshiaki; Morimoto, Takeshi; Shiomi, Hiroki; Yamaji, Kyohei; Ando, Kenji; Ono, Koh; Shizuta, Satoshi; Saito, Naritatsu; Kato, Takao; Kaji, Shuichiro; Furukawa, Yutaka; Nakagawa, Yoshihisa; Kadota, Kazushige; Horie, Minoru; Kimura, Takeshi

2018-06-01

To clarify the effect of single-session multivessel percutaneous coronary intervention (PCI) strategy relative to the staged multivessel strategy on clinical outcomes in patients with stable coronary artery disease (CAD) or non-ST-elevation acute coronary syndrome. In the Coronary REvascularisation Demonstrating Outcome Study in Kyoto PCI/coronary artery bypass grafting registry cohort-2, there were 2018 patients who underwent elective multivessel PCI. Primary outcome measure was composite of all-cause death, myocardial infarction and stroke at 5-year follow-up. Single-session multivessel PCI and staged multivessel PCI were performed in 707 patients (35.0%) and 1311 patients (65.0%), respectively. The cumulative 5-year incidence of and adjusted risk for the primary outcome measure were not significantly different between the single-session and staged groups (26.7% vs 23.0%, p=0.45; HR 0.91, 95% CI 0.72 to 1.16, p=0.47). The 30-day incidence of all-cause death was significantly higher in the single-session group than in the staged group (1.1% vs 0.2%, p=0.009). However, the causes of death in 11 patients who died within 30 days were generally not related to the procedural complications, but related to the serious clinical status before PCI. For the subgroup analyses including age, gender, extent of CAD, severe chronic kidney disease and heart failure, there was no significant interaction between the subgroup factors and the effect of the single-session strategy relative to the staged strategy for the primary outcome measure. The single-session multivessel PCI strategy was associated with at least comparable 5-year clinical outcomes compared with the staged multivessel PCI, although the prevalence of the single-session strategy was low in the present study. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Single-stage accelerator mass spectrometer radiocarbon-interference identification and positive-ionisation characterisation

Energy Technology Data Exchange (ETDEWEB)

Wilcken, K.M., E-mail: klaus.wilcken@ansto.gov.au [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom); Freeman, S.P.H.T.; Xu, S.; Dougans, A. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom)

2013-01-15

A single-stage accelerator mass spectrometer (SSAMS) is a good alternative to conventional spectrometers based on tandem electrostatic acceleration for radiocarbon measurement and permits experimentation with both negative and positive carbon ions. However, such {sup 14}C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed {sup 13}C and {sup 16}O by improvising an additional Wien filter on our SSAMS deck. Also, {sup 14}C AMS might be improved by removing its dependency on negative-ionisation in a sputter ion source. This requires negative-ionisation of sample atoms elsewhere to suppress the {sup 14}N interference, which we accomplish by transmitting initially positive ions through a thin membrane. The ionisation dependence on ion-energy is found to be consistent with previous experimentation with vapours and thicker foils.

The Lifetime Estimate for ACSR Single-Stage Splice Connector Operating at Higher Temperatures

International Nuclear Information System (INIS)

Wang, Jy-An John; Graziano, Joe; Chan, John

2011-01-01

This paper is the continuation of Part I effort to develop a protocol of integrating analytical and experimental approaches to evaluate the integrity of a full tension single-stage splice connector (SSC) assembly during service at high operating temperature.1The Part II efforts are mainly focused on the thermal mechanical testing, thermal-cycling simulation and its impact on the effective lifetime of the SSC system. The investigation indicates that thermal cycling temperature and frequency, conductor cable tension loading, and the compressive residual stress field within a SSC system have significant impact on the SSC integrity and the associated effective lifetime.

Comparing a single-stage geocoding method to a multi-stage geocoding method: how much and where do they disagree?

Directory of Open Access Journals (Sweden)

Rice Kenneth

2007-03-01

Full Text Available Abstract Background Geocoding methods vary among spatial epidemiology studies. Errors in the geocoding process and differential match rates may reduce study validity. We compared two geocoding methods using 8,157 Washington State addresses. The multi-stage geocoding method implemented by the state health department used a sequence of local and national reference files. The single-stage method used a single national reference file. For each address geocoded by both methods, we measured the distance between the locations assigned by each method. Area-level characteristics were collected from census data, and modeled as predictors of the discordance between geocoded address coordinates. Results The multi-stage method had a higher match rate than the single-stage method: 99% versus 95%. Of 7,686 addresses were geocoded by both methods, 96% were geocoded to the same census tract by both methods and 98% were geocoded to locations within 1 km of each other by the two methods. The distance between geocoded coordinates for the same address was higher in sparsely populated and low poverty areas, and counties with local reference files. Conclusion The multi-stage geocoding method had a higher match rate than the single-stage method. An examination of differences in the location assigned to the same address suggested that study results may be most sensitive to the choice of geocoding method in sparsely populated or low-poverty areas.

Single-stage Acetabular Revision During Two-stage THA Revision for Infection is Effective in Selected Patients.

Science.gov (United States)

Fink, Bernd; Schlumberger, Michael; Oremek, Damian

2017-08-01

The treatment of periprosthetic infections of hip arthroplasties typically involves use of either a single- or two-stage (with implantation of a temporary spacer) revision surgery. In patients with severe acetabular bone deficiencies, either already present or after component removal, spacers cannot be safely implanted. In such hips where it is impossible to use spacers and yet a two-stage revision of the prosthetic stem is recommended, we have combined a two-stage revision of the stem with a single revision of the cup. To our knowledge, this approach has not been reported before. (1) What proportion of patients treated with single-stage acetabular reconstruction as part of a two-stage revision for an infected THA remain free from infection at 2 or more years? (2) What are the Harris hip scores after the first stage and at 2 years or more after the definitive reimplantation? Between June 2009 and June 2014, we treated all patients undergoing surgical treatment for an infected THA using a single-stage acetabular revision as part of a two-stage THA exchange if the acetabular defect classification was Paprosky Types 2B, 2C, 3A, 3B, or pelvic discontinuity and a two-stage procedure was preferred for the femur. The procedure included removal of all components, joint débridement, definitive acetabular reconstruction (with a cage to bridge the defect, and a cemented socket), and a temporary cemented femoral component at the first stage; the second stage consisted of repeat joint and femoral débridement and exchange of the femoral component to a cementless device. During the period noted, 35 patients met those definitions and were treated with this approach. No patients were lost to followup before 2 years; mean followup was 42 months (range, 24-84 months). The clinical evaluation was performed with the Harris hip scores and resolution of infection was assessed by the absence of clinical signs of infection and a C-reactive protein level less than 10 mg/L. All

Single stage three level grid interactive MPPT inverter for PV systems

International Nuclear Information System (INIS)

Ozdemir, Saban; Altin, Necmi; Sefa, Ibrahim

2014-01-01

Highlights: • A three phase three-level NPC inverter for grid interactive PV systems is proposed. • A novel MPPT algorithm is introduced for single stage systems. • The proposed algorithm is robust with respect to parameter variations of PV system. • THD level is measured as 3.45% and it meets the international standards (<5%). • Total system efficiency is measured as 93.08%. - Abstract: In this study, three-phase, single stage neutral point clamped grid interactive inverter is designed and implemented. The reference current of the voltage source inverter is determined by maximum power point tracking sub-program in order to obtain maximum power from photovoltaic modules instantaneously. Proposed control is realized via TMS320F28335 32-bit floating point processor. The modified incremental conductance method is applied for maximum power point tracking; the PI regulator is used to control the inverter output current shape and level. Galvanic isolation is provided by a line frequency transformer that matches inverter output voltage to the grid voltage level and prevents DC current injection into the grid. Experimental results show that the designed inverter imports energy to the grid with unity power factor, total harmonic distortion level is 3.45% and this value is in the limits of the international standards. In addition, the total efficiency of the system is measured as 93.08%. The proposed system gets the maximum power from photovoltaic module and dispatches into the grid without using additional DC/DC converter

Investigation of Advanced Propellants to Enable Single Stage to Orbit Launch Vehicles

National Research Council Canada - National Science Library

Mossman, Jason

2006-01-01

Single-Stage-To-Orbit (SSTO) launch vehicles designs offer the promise of reduced complexity and cost compared to multi-stage vehicles, as only one stage need be developed, produced, and maintained...

Single-Phase Single-Stage Grid Tied Solar PV System with Active Power Filtering Using Power Balance Theory

Science.gov (United States)

Singh, Yashi; Hussain, Ikhlaq; Singh, Bhim; Mishra, Sukumar

2018-03-01

In this paper, power quality features such as harmonics mitigation, power factor correction with active power filtering are addressed in a single-stage, single-phase solar photovoltaic (PV) grid tied system. The Power Balance Theory (PBT) with perturb and observe based maximum power point tracking algorithm is proposed for the mitigation of power quality problems in a solar PV grid tied system. The solar PV array is interfaced to a single phase AC grid through a Voltage Source Converter (VSC), which provides active power flow from a solar PV array to the grid as well as to the load and it performs harmonics mitigation using PBT based control. The solar PV array power varies with sunlight and due to this, the solar PV grid tied VSC works only 8-10 h per day. At night, when PV power is zero, the VSC works as an active power filter for power quality improvement, and the load active power is delivered by the grid to the load connected at the point of common coupling. This increases the effective utilization of a VSC. The system is modelled and simulated using MATLAB and simulated responses of the system at nonlinear loads and varying environmental conditions are also validated experimentally on a prototype developed in the laboratory.

Numerical Simulation of single-stage axial fan operation under dusty flow conditions

Science.gov (United States)

Minkov, L. L.; Pikushchak, E. V.

2017-11-01

Assessment of the aerodynamic efficiency of the single-stage axial flow fan under dusty flow conditions based on a numerical simulation using the computational package Ansys-Fluent is proposed. The influence of dust volume fraction on the dependences of the air volume flow rate and the pressure drop on the rotational speed of rotor is demonstrated. Matching functions for formulas describing a pressure drop and volume flow rate in dependence on the rotor speed and dust content are obtained by numerical simulation for the single-stage axial fan. It is shown that the aerodynamic efficiency of the single-stage axial flow fan decreases exponentially with increasing volume content of dust in the air.

Promising results after single-stage reconstruction of the nipple and areola complex

DEFF Research Database (Denmark)

Børsen-Koch, Mikkel; Bille, Camilla; Thomsen, Jørn B

2013-01-01

Introduction: Reconstruction of the nipple-areola complex (NAC) traditionally marks the end of breast reconstruction. Several different surgical techniques have been described, but most are staged procedures. This paper describes a simple single-stage approach. Material and Methods: We used...... reconstruction was 43 min. (30-50 min.). Conclusion: This simple single-stage NAC reconstruction seems beneficial for both patient and surgeon as it seems to be associated with faster reconstruction and reduced procedure-related time without compromising the aesthetic outcome or the morbidity associated...

Single-stage Modified Duhamel procedure for Hirschsprung′s disease : Our experience

Directory of Open Access Journals (Sweden)

Paras R Kothari

2012-01-01

Full Text Available Introduction: Primary single-stage pull-through for Hirschsprung′s disease (HD has been reported to give comparable surgical outcomes to staged operations with less morbidity. Herein, we present our experience with single-stage Modified Duhamel procedure for management of HD. Patients and Methods: This was a review of 48 cases of HD who underwent single-stage Modified Duhamel procedure without a protective colostomy. Results: The age at surgery ranged from 6 months to 10 years (median - 9 months, mean - 2.3 years. The average weight of the child was 7.2 kg (range, 4.9-22 kg. 38 (79.2% patients had classical rectosigmoid HD, the rest being long segment HD (the proximal most level being the splenic flexure. The average duration of surgery was 175 minutes (range, 130-245 minutes. The average blood loss was 45 ml. The average hospital stay was 7.2 days (range: 6-10 days. The major postoperative complications (n=3 included postoperative adhesive intestinal obstruction, anastomotic leak and persistent constipation due to residual aganglionosis. Each required a re-exploration. Minor complications included surgical site infection (n=3 and post-operative enterocolitis (n=3, which were managed conservatively. Six patients had constipation for a limited period post-operatively. All patients have a satisfactory functional outcome and normal development and growth. Conclusions: For HD, we recommend that single-stage Modified Duhamel procedure should be the preferred approach in view of its low morbidity, satisfactory functional outcome and avoidance of stoma, multiple surgeries and economic benefit in view of decreased hospital stay.

Lot-sizing for a single-stage single-product production system with rework of perishable production defectives

NARCIS (Netherlands)

Teunter, R.; Flapper, S.D.P.

2003-01-01

We consider a single-stage single-product production system. Produced units may be non-defective, reworkable defective, or non-reworkable defective. The system switches between production and rework. After producing a fixed number (N) of units, all reworkable defective units are reworked. Reworkable

A Single-Stage High-Power-Factor Light-Emitting Diode (LED Driver with Coupled Inductors for Streetlight Applications

Directory of Open Access Journals (Sweden)

Chun-An Cheng

2017-02-01

Full Text Available This paper presents and implements a single-stage high-power-factor light-emitting diode (LED driver with coupled inductors, suitable for streetlight applications. The presented LED driver integrates an interleaved buck-boost power factor correction (PFC converter with coupled inductors and a half-bridge-type series-resonant converter cascaded with a full-bridge rectifier into a single-stage power conversion circuit. Coupled inductors inside the interleaved buck-boost PFC converter sub-circuit are designed to operate in discontinuous conduction mode (DCM for achieving input-current shaping, and the half-bridge-type series resonant converter cascaded with a full-bridge rectifier is designed for obtaining zero-voltage switching (ZVS on two power switches to reduce their switching losses. Analysis of operational modes and design equations for the presented LED driver are described and included. In addition, the presented driver features a high power factor, low total harmonic distortion (THD of input current, and soft switching. Finally, a prototype driver is developed and implemented to supply a 165-W-rated LED streetlight module with utility-line input voltages ranging from 210 to 230 V. Experimental results demonstrate that high power factor (>0.99, low utility-line current THD (<7%, low-output voltage ripples (<1%, low-output current ripples (<10%, and high circuit efficiency (>90% are obtained in the presented single-stage driver for LED streetlight applications.

Single-stage versus two-stage anaerobic fluidized bed bioreactors in treating municipal wastewater: Performance, foulant characteristics, and microbial community.

Science.gov (United States)

Wu, Bing; Li, Yifei; Lim, Weikang; Lee, Shi Lin; Guo, Qiming; Fane, Anthony G; Liu, Yu

2017-03-01

This study examined the receptive performance, membrane foulant characteristics, and microbial community in the single-stage and two-stage anaerobic fluidized membrane bioreactor (AFMBR) treating settled raw municipal wastewater with the aims to explore fouling mechanisms and microbial community structure in both systems. Both AFMBRs exhibited comparable organic removal efficiency and membrane performances. In the single-stage AFMBR, less soluble organic substances were removed through biosorption by GAC and biodegradation than those in the two-stage AFMBR. Compared to the two-stage AFMBR, the formation of cake layer was the main cause of the observed membrane fouling in the single-stage AFMBR at the same employed flux. The accumulation rate of the biopolymers was linearly correlated with the membrane fouling rate. In the chemical-cleaned foulants, humic acid-like substances and silicon were identified as the predominant organic and inorganic fouants respectively. As such, the fluidized GAC particles might not be effective in removing these substances from the membrane surfaces. High-throughout pyrosequencing analysis further revealed that beta-Proteobacteria were predominant members in both AFMBRs, which contributed to the development of biofilms on the fluidized GAC and membrane surfaces. However, it was also noted that the abundance of the identified dominant in the membrane surface-associated biofilm seemed to be related to the permeate flux and reactor configuration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-disciplinary design optimization and performance evaluation of a single stage transonic axial compressor

International Nuclear Information System (INIS)

Lee, Sae Il; Lee, Dong Ho; Kim, Kyu Hong; Park, Tae Choon; Lim, Byeung Jun; Kang, Young Seok

2013-01-01

The multidisciplinary design optimization method, which integrates aerodynamic performance and structural stability, was utilized in the development of a single-stage transonic axial compressor. An approximation model was created using artificial neural network for global optimization within given ranges of variables and several design constraints. The genetic algorithm was used for the exploration of the Pareto front to find the maximum objective function value. The final design was chosen after a second stage gradient-based optimization process to improve the accuracy of the optimization. To validate the design procedure, numerical simulations and compressor tests were carried out to evaluate the aerodynamic performance and safety factor of the optimized compressor. Comparison between numerical optimal results and experimental data are well matched. The optimum shape of the compressor blade is obtained and compared to the baseline design. The proposed optimization framework improves the aerodynamic efficiency and the safety factor.

Effects of Hot Streak Shape on Rotor Heating in a High-Subsonic Single-Stage Turbine

Science.gov (United States)

Dorney, Daniel J.; Gundy-Burlet, Karen L.; Norvig, Peter (Technical Monitor)

1999-01-01

Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location (clocking) of the hot streak relative to the first-stage vane airfoils can be used to minimize the adverse effects of the hot streak. The effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils have also been evaluated. In the present investigation, three-dimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine operating in high subsonic flow. In addition to a simulation of the baseline turbine, simulations have been performed for circular and elliptical hot streaks of varying sizes in an effort to represent different combustor designs. The predicted results for the baseline simulation show good agreement with the available experimental data. The results of the hot streak simulations indicate: that a) elliptical hot streaks mix more rapidly than circular hot streaks, b) for small hot streak surface area the average rotor temperature is not a strong function of hot streak temperature ratio or shape, and c) hot streaks with larger surface area interact with the secondary flows at the rotor hub endwall, generating an additional high temperature region.

Single-stage anterior high sacrectomy for locally recurrent rectal cancer.

Science.gov (United States)

Fawaz, Khaled; Khaled, Fawaz; Smith, Myles J; Moises, Cukier; Smith, Andrew J; Yee, Albert J M

2014-03-01

A review of prospectively collected data on a consecutive series of patients undergoing single-stage anterior high sacrectomy for locally recurrent rectal carcinoma (LRRC). To determine the clinical outcome of patients who underwent anterior high sacrectomy for LRRC. High sacrectomy for oncological resection remains technically challenging. Surgery has the potential to achieve cure in carefully selected patients. Complete (R0) tumor excision in LRRC may require sacrectomy. High sacral resections (S3 and above) typically require a combined anterior/supine and posterior/prone procedure. We investigated our experience performing single-stage anterior high sacrectomy for LRRC. A consecutive series of patients with LRRC without systemic metastases who underwent resection with curative intent requiring high sacrectomy were identified. A review of a prospectively maintained colorectal and spine cancer database data was performed. An oblique dome high sacral osteotomy was performed during a single-stage anterior procedure. Outcome measures included surgical resection margin status, hospital length of stay, postoperative complications, physical functioning status, and overall survival. Nineteen consecutive patients were treated between 2002 and 2011. High sacrectomy was performed at sacral level S1-S2 in 4 patients, S2-S3 in 9 patients, and through S3 in 6 patients. An R0 resection margin was achieved histologically in all 19 cases. There was 1 early (<30 d) postoperative death (1/19, 5%). At median follow-up of 38 months, 13 patients had no evidence of residual disease, 1 was alive with disease, and 4 had died of disease. Morbidities occurred in 15 of the 19 patients (79%). Although high sacrectomy may require a combined anterior and posterior surgical approach, our series demonstrates the feasibility of performing single-stage anterior high sacrectomy in LRRC, with acceptable risks and outcomes compared with the literature. The procedure described by us for LRRC lessens

Development of the virtual experimental bench on the basis of modernized research centrifugal compressor stage test unit with the 3D impeller.

Science.gov (United States)

Aksenov, A. A.; Danilishin, A. M.; Dubenko, A. M.; Kozhukov, Y. V.

2017-08-01

Design modernization of the centrifugal compressor stage test bench with three dimensional impeller blades was carried out for the possibility of holding a series of experimental studies of different 3D impeller models. The studies relates to the problem of joint work of the impeller and the stationary channels of the housing when carrying out works on modernization with the aim of improving the parameters of the volumetric capacity or pressure in the presence of design constraints. The object of study is the experimental single end centrifugal compressor stage with the 3D impeller. Compressor stage consists of the 3D impeller, vaneless diffuser (VLD), outlet collector - folded side scroll and downstream pipe. The drive is a DC motor 75 kW. The increase gear (multiplier) was set between the compressor and DC motor, gear ratio is i = 9.8. To obtain the characteristics of the compressor and the flow area the following values were measured: total pressure, static pressure, direction (angles) of the stream in different cross sections. Additional pneumometric probes on the front wall of the VLD of the test bench have been installed. Total pressure probes and foster holes for the measurement of total and static pressure by the new drainage scheme. This allowed carrying out full experimental studies for two elements of centrifugal compressor stage. After the experimental tests the comprehensive information about the performance of model stage were obtained. Was measured geometric parameters and the constructed virtual model of the experimental bench flow part with the help of Creo Parametric 3.0 and ANSYS v. 16.2. Conducted CFD calculations and verification with experimental data. Identifies the steps for further experimental and virtual works.

Experimental studies of two-stage centrifugal dust concentrator

Science.gov (United States)

Vechkanova, M. V.; Fadin, Yu M.; Ovsyannikov, Yu G.

2018-03-01

The article presents data of experimental results of two-stage centrifugal dust concentrator, describes its design, and shows the development of a method of engineering calculation and laboratory investigations. For the experiments, the authors used quartz, ceramic dust and slag. Experimental dispersion analysis of dust particles was obtained by sedimentation method. To build a mathematical model of the process, dust collection was built using central composite rotatable design of the four factorial experiment. A sequence of experiments was conducted in accordance with the table of random numbers. Conclusion were made.

System and method for single-phase, single-stage grid-interactive inverter

Science.gov (United States)

Liu, Liming; Li, Hui

2015-09-01

The present invention provides for the integration of distributed renewable energy sources/storages utilizing a cascaded DC-AC inverter, thereby eliminating the need for a DC-DC converter. The ability to segment the energy sources and energy storages improves the maintenance capability and system reliability of the distributed generation system, as well as achieve wide range reactive power compensation. In the absence of a DC-DC converter, single stage energy conversion can be achieved to enhance energy conversion efficiency.

Evaluation of an automated single-channel sleep staging algorithm

Directory of Open Access Journals (Sweden)

Wang Y

2015-09-01

Full Text Available Ying Wang,1 Kenneth A Loparo,1,2 Monica R Kelly,3 Richard F Kaplan1 1General Sleep Corporation, Euclid, OH, 2Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, 3Department of Psychology, University of Arizona, Tucson, AZ, USA Background: We previously published the performance evaluation of an automated electroencephalography (EEG-based single-channel sleep–wake detection algorithm called Z-ALG used by the Zmachine® sleep monitoring system. The objective of this paper is to evaluate the performance of a new algorithm called Z-PLUS, which further differentiates sleep as detected by Z-ALG into Light Sleep, Deep Sleep, and Rapid Eye Movement (REM Sleep, against laboratory polysomnography (PSG using a consensus of expert visual scorers. Methods: Single night, in-lab PSG recordings from 99 subjects (52F/47M, 18–60 years, median age 32.7 years, including both normal sleepers and those reporting a variety of sleep complaints consistent with chronic insomnia, sleep apnea, and restless leg syndrome, as well as those taking selective serotonin reuptake inhibitor/serotonin–norepinephrine reuptake inhibitor antidepressant medications, previously evaluated using Z-ALG were re-examined using Z-PLUS. EEG data collected from electrodes placed at the differential-mastoids (A1–A2 were processed by Z-ALG to determine wake and sleep, then those epochs detected as sleep were further processed by Z-PLUS to differentiate into Light Sleep, Deep Sleep, and REM. EEG data were visually scored by multiple certified polysomnographic technologists according to the Rechtschaffen and Kales criterion, and then combined using a majority-voting rule to create a PSG Consensus score file for each of the 99 subjects. Z-PLUS output was compared to the PSG Consensus score files for both epoch-by-epoch (eg, sensitivity, specificity, and kappa and sleep stage-related statistics (eg, Latency to Deep Sleep, Latency to REM

Experimental techniques for single cell and single molecule biomechanics

International Nuclear Information System (INIS)

Lim, C.T.; Zhou, E.H.; Li, A.; Vedula, S.R.K.; Fu, H.X.

2006-01-01

Stresses and strains that act on the human body can arise either from external physical forces or internal physiological environmental conditions. These biophysical interactions can occur not only at the musculoskeletal but also cellular and molecular levels and can determine the health and function of the human body. Here, we seek to investigate the structure-property-function relationship of cells and biomolecules so as to understand their important physiological functions as well as establish possible connections to human diseases. With the recent advancements in cell and molecular biology, biophysics and nanotechnology, several innovative and state-of-the-art experimental techniques and equipment have been developed to probe the structural and mechanical properties of biostructures from the micro- down to picoscale. Some of these experimental techniques include the optical or laser trap method, micropipette aspiration, step-pressure technique, atomic force microscopy and molecular force spectroscopy. In this article, we will review the basic principles and usage of these techniques to conduct single cell and single molecule biomechanics research

Use of skin stretchers for single-stage bilateral mastectomies in a dog and a cat.

Science.gov (United States)

Miyazaki, Yuta; Aikawa, Takeshi; Shimatsu, Taichi; Nishimura, Masaaki; Sadahiro, Shigeo

2018-04-01

To describe the application of skin stretchers for closure of single-stage bilateral mastectomies in a dog and a cat. Clinical case report. A 12-year-old intact female Miniature Dachshund and a 13-year-old spayed female domestic short-hair cat. Skin stretchers were applied to the site of the skin adjacent to mammary glands for 2-4 days before surgery. Cable tension was adjusted every 6-8 hours to elongate the skin and to achieve primary closure of single-stage bilateral mastectomy without tension. Wound closure after single-stage bilateral mastectomy was achieved without tension or major complication in both animals. Use of skin stretchers allows primary closure of single-stage bilateral mastectomy in dogs and cats. © 2017 The American College of Veterinary Surgeons.

Investigation of different ethylenediamine-N,N'-disuccinic acid-enhanced washing configurations for remediation of a Cu-contaminated soil: process kinetics and efficiency comparison between single-stage and multi-stage configurations.

Science.gov (United States)

Ferraro, Alberto; Fabbricino, Massimiliano; van Hullebusch, Eric D; Esposito, Giovanni

2017-09-01

A comparison of Cu extraction yields for three different ethylenediamine-N,N'-disuccinic acid (EDDS)-enhanced washing configurations was performed on a Cu-contaminated soil. Batch experiments were used to simulate a single-stage continuous stirred tank reactor (CSTR) and a multi-stage (side feeding and counter-current) reactor. Single-stage CSTR conditions were simulated for various EDDS:(Cu + Cd + Pb + Co + Ni + Zn) molar ratio (EDDS:M ratio) (from 1 to 30) and liquid to soil (L/S) ratio (from 15 to 45). The highest Cu extraction yield (≃56%) was achieved with EDDS:M = 30. In contrast, a Cu extraction yield decrease was observed with increasing L/S ratio with highest extracted Cu achievement (≃48%) for L/S = 15. Side feeding configuration was tested in four experimental conditions through different fractionation mode of EDDS dose and treatment time at each washing step. Results from the four tests showed all enhanced Cu extraction (maximum values from ≃43 to ≃51%) achieved at lower treatment time and lower EDDS:M molar ratio compared to CSTR configuration with L/S = 25 and EDDS:M = 10. The counter-current washing was carried out through two washing flows achieving a process performance enhancement with 27% increase of extracted Cu compared to single-stage CSTR configuration. Higher Cu extraction percentage (36.8%) was observed in the first washing phase than in the second one (24.7%).

Experimental investigation on the initial expansion stage of vacuum arc on cup-shaped TMF contacts

Science.gov (United States)

Wang, Ting; Xiu, Shixin; Liu, Zixi; Zhang, Yanzhe; Feng, Dingyu

2018-02-01

Arc behavior and measures to control it directly affect the properties of vacuum circuit breakers. Nowadays, transverse magnetic field (TMF) contacts are widely used for medium voltages. A magnetic field perpendicular to the current direction between the TMF contacts makes the arc move, transmitting its energy to the whole contact and avoiding excessive local ablation. Previous research on TMF arc behavior concentrated mainly on the arc movement and less on the initial stage (from arc ignition to an unstable arc column). A significant amount of experiment results suggest that there is a short period of arc stagnation after ignition. The duration of this arc stagnation and the arc characteristics during this stage affect the subsequent arc motion and even the breaking property of interrupters. The present study is of the arc characteristics in the initial stage. Experiments were carried out in a demountable vacuum chamber with cup-shaped TMF contacts. Using a high-speed camera, both single-point arc ignition mode and multiple-point arc ignition (MPAI) mode were observed. The experimental data show that the probability of MPAI mode occurring is related to the arc current. The influences of arc-ignition mode, arc current, and contact diameter on the initial expansion process were investigated. In addition, simulations were performed to analyze the multiple arc expansion process mechanically. Based on the experimental phenomena and simulation results, the mechanism of the arc expansion motion was analyzed.

The efficacy of single-stage open intramedullary nailing of neglected femur fractures.

Science.gov (United States)

Boopalan, P R J V C; Sait, Azad; Jepegnanam, Thilak Samuel; Matthai, Thomas; Varghese, Viju Daniel

2014-02-01

Neglected femur fractures are not rare in the developing world. Treatment options include single-stage open reduction and intramedullary nailing, or open release, skeletal traction, and then second-stage open intramedullary nailing, with bone grafting. Single-stage procedures have the potential advantage of avoiding neurovascular complications secondary to acute lengthening, but they require a second operation, with potentially increased resource use and infection risk. We sought to determine the (1) likelihood of union, (2) complications and reoperations, and (3) functional results with single-stage open intramedullary nailing without bone grafting in patients with neglected femur fractures. Between January 2003 and December 2007, 17 consecutive patients presented to our practice with neglected femoral shaft fractures. All were treated with single-stage nailing without bone grafting. There were 15 men and two women with a median age of 27 years. The average time from fracture to treatment was 13 weeks (range, 4-44 weeks). Eleven patients underwent open nailing with interlocked nails and six were treated with cloverleaf Kuntscher nails. Patients were followed for a minimum of 6 months (mean, 33 months; range, 6-72 months). The mean preoperative ROM of the knee was 28° (range, 10°-150°) and femoral length discrepancy was 3.1 cm (range, 1-5 cm). All fractures united and the mean time to union was 16 weeks (range, 7-32 weeks). There were no neurologic complications secondary to acute lengthening. The mean postoperative ROM of the knee was 130° (range, 60°-150°). All patients were able to return to preinjury work. Sixteen patients regained their original femoral length. One-stage open intramedullary nailing of neglected femoral diaphyseal fractures without bone grafting was safe and effective, and obviated the need for a two-stage approach. Although the findings need to be replicated in larger numbers of patients, we believe this technique may be useful in

Early stage of deformation in tungsten, tantalum, and nickel single crystals

International Nuclear Information System (INIS)

Pinatti, D.G.

1977-01-01

High purity Tantalum, Tungsten and Nickel single crystals were tested in simple tension between 77 and 300 K. The Ta and W was oriented for maximum resolved shear stress on the [111] (101) system. Simultaneously microstrain and ultrasonic propagation measurements (attenuation and modulus defect) were performed at various stress bias in order to test details of theories concerning the preyield region and the flow stress in body-centered cubic refractory metals. The experimental retical predictions for the kink chain model over the string model for dislocation. It appears that double kink nucleation in non-screw dislocations has negligible effect in this domains. The results for annealed Ta exhibited no stress bias effect on the ultrasonic propagation measurements, which suggest that the strong influence of impurities mask our ability to discern this fine structure for dislocation motion. For prestrained W and Ta, it was found that double-kink nucleation on nonscrew dislocation plays an important role and revealed interesting results with respect to our understanding of the intrinsic dislocation structure in bcc metals. These results support the kink chain model for dislocation unambiguously. The experiments on the prestrained samples also exhibited experimental results which are qualitatively but not quantitatively in agreement with the theoretical predictions of Seeger and Sectak. The Ni single crystals were prestrained between 10 and 23 percent in stage II, and the microstrain damping loops have been studied as a function of stress amplitude, temperature and magnetic field. The predominant hysteretic contribution to the observed decrement was analyzed according to the model of Roberts (Al. 14, Al. 15), and good agreement between theory and experiment was found

The early stages of oxidation of magnesium single crystal surfaces

International Nuclear Information System (INIS)

Hayden, B.E.; Schweizer, E.; Koetz, R.; Bradshaw, A.M.

1981-01-01

The early stages of oxidation of Mg(001) and Mg(100) single crystal surfaces at 300 K have been investigated by LEED, ELS, work function and ellipsometric measurements. A sharp decrease in work function on both surfaces during the first 12 L exposure indicates the incorporation of oxygen in the earliest stages of the interaction. The incorporated oxygen on Mg(001) gives rise to a broadening of the integral order LEED spots for an exposure 3 L. (orig.)

Design of single piece sabot for a single stage gas gun

Science.gov (United States)

Vemparala, Vignesh; Mathew, Arun Tom; Rao Koka, Tirumala

2017-11-01

Single piece sabot is a vital part in single stage gas guns for impact testing in aerospace industries. Depending on the type of projectile used the design of sabot varies to accommodate the testing equipment. The velocity of the projectile exiting the barrel is dependent on the material and shape of the sabot used. The material selected for the design of sabot is rigid polyurethane foam, due to their low elastic modulus and low density. Two samples of rigid PU foam is taken and tests are performed to get their exact material properties. These properties are incorporated in numerical simulation to determine the best fit for practical use. Since the PU foams has a wide range of porosity which plays a prominent role in deciding the exit velocity and accuracy of the projectile coming out of the barrel. By optimisation, to the best suitable material sample can be determined.

Nitrite reduction and methanogenesis in a single-stage UASB reactor.

Science.gov (United States)

Borges, L I; López-Vazquez, C M; García, H; van Lier, J B

2015-01-01

In this study, nitrite reduction and methanogenesis in a single-stage upflow anaerobic sludge blanket (UASB) reactor was investigated, using high-strength synthetic domestic wastewater as substrate. To assess long-term effects and evaluate the mechanisms that allow successful nitrite reduction and methanogenesis in a single-stage UASB, sludge was exposed to relatively high nitrite loading rates (315 ± 13 mgNO(2)(-)-N/(l.d)), using a chemical oxygen demand (COD) to nitrogen ratio of 18 gCOD/gNO(2)(-)-N, and an organic loading rate of 5.4 ± 0.2 gCOD/(l.d). In parallel, the effects of sludge morphology on methanogenesis inhibition were studied by performing short-term batch activity tests at different COD/NO(2)(-)-N ratios with anaerobic sludge samples. In long-term tests, denitrification was practically complete and COD removal efficiency did not change significantly after nitrite addition. Furthermore, methane production only decreased by 13%, agreeing with the reducing equivalents requirement for complete NO(2)(-) reduction to N₂. Apparently, the spatial separation of denitrification and methanogenesis zones inside the UASB reactor allowed nitrite reduction and methanogenesis to occur at the same moment. Batch tests showed that granules seem to protect methanogens from nitrite inhibition, probably due to transport limitations. Combined COD and N removal via nitrite in a single-stage UASB reactor could be a feasible technology to treat high-strength domestic wastewater.

Experimental and numerical studies on two-stage combustion of biomass

Energy Technology Data Exchange (ETDEWEB)

Houshfar, Eshan

2012-07-01

In this thesis, two-stage combustion of biomass was experimentally/numerically investigated in a multifuel reactor. The following emissions issues have been the main focus of the work: 1- NOx and N2O 2- Unburnt species (CO and CxHy) 3- Corrosion related emissions.The study had a focus on two-stage combustion in order to reduce pollutant emissions (primarily NOx emissions). It is well known that pollutant emissions are very dependent on the process conditions such as temperature, reactant concentrations and residence times. On the other hand, emissions are also dependent on the fuel properties (moisture content, volatiles, alkali content, etc.). A detailed study of the important parameters with suitable biomass fuels in order to optimize the various process conditions was performed. Different experimental studies were carried out on biomass fuels in order to study the effect of fuel properties and combustion parameters on pollutant emissions. Process conditions typical for biomass combustion processes were studied. Advanced experimental equipment was used in these studies. The experiments showed the effects of staged air combustion, compared to non-staged combustion, on the emission levels clearly. A NOx reduction of up to 85% was reached with staged air combustion using demolition wood as fuel. An optimum primary excess air ratio of 0.8-0.95 was found as a minimizing parameter for the NOx emissions for staged air combustion. Air staging had, however, a negative effect on N2O emissions. Even though the trends showed a very small reduction in the NOx level as temperature increased for non-staged combustion, the effect of temperature was not significant for NOx and CxHy, neither in staged air combustion or non-staged combustion, while it had a great influence on the N2O and CO emissions, with decreasing levels with increasing temperature. Furthermore, flue gas recirculation (FGR) was used in combination with staged combustion to obtain an enhanced NOx reduction. The

NOFBX Single-Stage-to-Orbit Mars Ascent Vehicle Engine, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — We propose the continuation of our research and development of a Nitrous Oxide Fuel Blend (NOFBXTM) Single-Stage-to-Orbit (SSTO) monopropellant propulsion system for...

A Single-Stage LED Tube Lamp Driver with Power-Factor Corrections and Soft Switching for Energy-Saving Indoor Lighting Applications

Directory of Open Access Journals (Sweden)

Chun-An Cheng

2017-01-01

Full Text Available This paper presents a single-stage alternating current (AC/direct current (DC light-emitting diode (LED tube lamp driver for energy-saving indoor lighting applications; this driver features power-factor corrections and soft switching, and also integrates a dual buck-boost converter with coupled inductors and a half-bridge series resonant converter cascaded with a bridge rectifier into a single-stage power-conversion topology. The features of the presented driver are high efficiency (>91%, satisfying power factor (PF > 0.96, low input-current total-harmonic distortion (THD < 10%, low output voltage ripple factor (<7.5%, low output current ripple factor (<8%, and zero-voltage switching (ZVS obtained on both power switches. Operational principles are described in detail, and experimental results obtained from an 18 W-rated LED tube lamp for T8/T10 fluorescent lamp replacements with input utility-line voltages ranging from 100 V to 120 V have demonstrated the functionality of the presented driver suitable for indoor lighting applications.

Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation in surgical treatment for single-segment lumbar spinal tuberculosis

OpenAIRE

Zeng, Hao; Wang, Xiyang; Zhang, Penghui; Peng, Wei; Zhang, Yupeng; Liu, Zheng

2015-01-01

Objective: The aim of this study is to determine the feasibility and efficacy of surgical management of single-segment lumbar spinal tuberculosis (TB) by using single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation.Methods: Seventeen cases of single-segment lumbar TB were treated with single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reco...

Performance prediction method for a multi-stage Knudsen pump

Science.gov (United States)

Kugimoto, K.; Hirota, Y.; Kizaki, Y.; Yamaguchi, H.; Niimi, T.

2017-12-01

In this study, the novel method to predict the performance of a multi-stage Knudsen pump is proposed. The performance prediction method is carried out in two steps numerically with the assistance of a simple experimental result. In the first step, the performance of a single-stage Knudsen pump was measured experimentally under various pressure conditions, and the relationship of the mass flow rate was obtained with respect to the average pressure between the inlet and outlet of the pump and the pressure difference between them. In the second step, the performance of a multi-stage pump was analyzed by a one-dimensional model derived from the mass conservation law. The performances predicted by the 1D-model of 1-stage, 2-stage, 3-stage, and 4-stage pumps were validated by the experimental results for the corresponding number of stages. It was concluded that the proposed prediction method works properly.

Practical Considerations Concerning the Interleaved Transition Mode Single-stage Ballast

DEFF Research Database (Denmark)

Teodorescu, Remus; Kjær, Søren Bækhøj; Munk-Nielsen, Stig

2002-01-01

The aim of this paper is to present a novel single-stage interleaved ballast focusing on practical design aspects like: key current expression, overall losses, harmonic analysis of the differential-mode EMI current and preheating ballast function. A new preheating method is also presented. A PSPICE...

A portable high-power diode laser-based single-stage ceramic tile grout sealing system

Science.gov (United States)

Lawrence, J.; Schmidt, M. J. J.; Li, L.; Edwards, R. E.; Gale, A. W.

2002-02-01

By means of a 60 W high-power diode laser (HPDL) and a specially developed grout material the void between adjoining ceramic tiles has been successfully sealed. A single-stage process has been developed which uses a crushed ceramic tile mix to act as a tough, inexpensive bulk substrate and a glazed enamel surface to provide an impervious surface glaze. The single-stage ceramic tile grout sealing process yielded seals produced in normal atmospheric conditions that displayed no discernible cracks and porosities. The single-stage grout is simple to formulate and easy to apply. Tiles were successfully sealed with power densities as low as 200 kW/ mm2 and at rates of up to 600 mm/ min. Bonding of the enamel to the crushed ceramic tile mix was identified as being primarily due to van der Waals forces and, on a very small scale, some of the crushed ceramic tile mix material dissolving into the glaze. In terms of mechanical, physical and chemical characteristics, the single-stage ceramic tile grout was found to be far superior to the conventional epoxy tile grout and, in many instances, matched and occasionally surpassed that of the ceramic tiles themselves. What is more, the development of a hand-held HPDL beam delivery unit and the related procedures necessary to lead to the commercialisation of the single-stage ceramic tile grout sealing process are presented. Further, an appraisal of the potential hazards associated with the use of the HPDL in an industrial environment and the solutions implemented to ensure that the system complies with the relevant safety standards are given.

An experimentally validated simulation model for a four-stage spray dryer

DEFF Research Database (Denmark)

Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

2017-01-01

mathematical model is an index-1 differential algebraic equation (DAE) model with 12 states, 9 inputs, 8 disturbances, and 30 parameters. The parameters in the model are identified from well-excited experimental data obtained from the industrialtype spray dryer. The simulated outputs ofthe model are validated...... is divided into four consecutive stages: a primary spray drying stage, two heated fluid bed stages, and a cooling fluid bed stage. Each of these stages in the model is assumed ideally mixed and the dynamics are described by mass- and energy balances. These balance equations are coupled with constitutive...... equations such as a thermodynamic model, the water evaporation rate, the heat transfer rates, and an equation for the stickiness of the powder (glass transition temperature). Laboratory data is used to model the equilibrium moisture content and the glass transition temperature of the powder. The resulting...

Single-staged uniportal VATS in the supine position for simultaneous bilateral primary spontaneous pneumothorax.

Science.gov (United States)

Kim, Kyung Soo

2017-05-15

Simultaneous bilateral primary spontaneous pneumothorax (SBPSP) is rare, but requires surgery on both sides, in patients with definite bilateral bullae to prevent life-threatening conditions. Recently, uniportal video-assisted thoracoscopic surgery (VATS) has been widely accepted as a less invasive technique for the treatment of pneumothorax. Thus, we introduced single-staged uniportal VATS technique in the supine position, for the management of two cases of SBPSP. A 17-year-old boy presented with bilateral spontaneous pneumothorax and he underwent single-staged uniportal VATS in the supine position. Single wide draping in consecutive bilateral approaches removes the needs of changing patients' position. Whole thoracoscopic procedure for wedge resection of bullae lesions was conducted without difficulty. The total operation time took 65 min and the patient discharged 3 days after the operation. The patient was followed for 24 months without recurrence of both sides. Another 18-year-old boy was admitted with bilateral spontaneous pneumothorax and single-staged uniportal VATS was also performed in the supine position. The total operation time took 79 min and the patient discharged on postoperative day 4. He was followed for 19 months without recurrence of both sides. Single-staged uniportal VATS approach yielded satisfactory results from simplicity that not requires position change compared to conventional multi-ports VATS in the lateral position, and with better cosmetics. This technique is thought to be a feasible procedure in selective patients with SBPSP or with contralateral bullae for preventive role.

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.

Evidence for vacancy migration in stage III for copper

International Nuclear Information System (INIS)

Antesberger, G.; Sonnenberg, K.; Wienhold, P.; Coltman, R.R.; Klabunde, C.E.; Williams, J.M.

1975-01-01

Specimens doped with interstitial clusters and single vacancies have been annealed isochronally through the temperature range of stage III. Combining this annealing with a test irradiation after each annealing step reactions of mobile single test interstitials with the doping defects were studied. These reactions provide information about the variation of the doping defect structure during annealing. The experimental results suggest that vacancy clusters are formed in stage III

Pre-design stage of the intermediate heat exchanger for experimental fast reactor

International Nuclear Information System (INIS)

Luz, M.; Borges, E.M.; Braz Filho, F.A.; Hirdes, V.R.

1986-09-01

This report presents the outlines of a thermal-hydraulic calculation procedure for the pre-design stage of the Intermediate Heat Exchanger for a 5 MW Experimental Fast Reactor (EFR), which can be used in other similar projects, at the same stage of evolution. Heat transfer and heat loss computations for the preliminary design of the heat exchanger are presented. (author) [pt

Single-stage osseointegrated implants for nasal prosthodontic rehabilitation: A clinical report.

Science.gov (United States)

de Carvalho, Bruna M D F; Freitas-Pontes, Karina M; de Negreiros, Wagner A; Verde, Marcus A R L

2015-08-01

Malignant tumors in the nasal region may be treated by means of invasive surgical procedures, with large facial losses. Nasal prostheses, retained by osseointegrated facial implants, instead of plastic surgery, will, in most patients, offer good biomechanical and cosmetic results. This clinical report describes the prosthetic rehabilitation of a patient with nasal cancer who had the entire nasal vestibule removed in a single-stage surgical procedure in order to shorten the rehabilitation time. The nasal prosthesis was built on a 3-magnet bar and was made of platinum silicone with intrinsic pigmentation, thereby restoring the patient's appearance and self-esteem. The authors concluded that single-stage implants may reduce the rehabilitation time to as little as 1 month, and the correct use of materials and techniques may significantly improve the nasal prosthesis. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Recording single neurons' action potentials from freely moving pigeons across three stages of learning.

Science.gov (United States)

Starosta, Sarah; Stüttgen, Maik C; Güntürkün, Onur

2014-06-02

While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed single-neuron activity while animals are acquiring an operantly conditioned response, or when that response is extinguished. But even in these cases, observation periods usually encompass only a single stage of learning, i.e. acquisition or extinction, but not both (exceptions include protocols employing reversal learning; see Bingman et al.(1) for an example). However, acquisition and extinction entail different learning mechanisms and are therefore expected to be accompanied by different types and/or loci of neural plasticity. Accordingly, we developed a behavioral paradigm which institutes three stages of learning in a single behavioral session and which is well suited for the simultaneous recording of single neurons' action potentials. Animals are trained on a single-interval forced choice task which requires mapping each of two possible choice responses to the presentation of different novel visual stimuli (acquisition). After having reached a predefined performance criterion, one of the two choice responses is no longer reinforced (extinction). Following a certain decrement in performance level, correct responses are reinforced again (reacquisition). By using a new set of stimuli in every session, animals can undergo the acquisition-extinction-reacquisition process repeatedly. Because all three stages of learning occur in a single behavioral session, the paradigm is ideal for the simultaneous observation of the spiking output of multiple single neurons. We use pigeons as model systems, but the task can easily be adapted to any other species capable of conditioned discrimination learning.

Two-stage single-volume exchange transfusion in severe hemolytic disease of the newborn.

Science.gov (United States)

Abbas, Wael; Attia, Nayera I; Hassanein, Sahar M A

2012-07-01

Evaluation of two-stage single-volume exchange transfusion (TSSV-ET) in decreasing the post-exchange rebound increase in serum bilirubin level, with subsequent reduction of the need for repeated exchange transfusions. The study included 104 neonates with hyperbilirubinemia needing exchange transfusion. They were randomly enrolled into two equal groups, each group comprised 52 neonates. TSSV-ET was performed for the 52 neonates and the traditional single-stage double-volume exchange transfusion (SSDV-ET) was performed to 52 neonates. TSSV-ET significantly lowered rebound serum bilirubin level (12.7 ± 1.1 mg/dL), compared to SSDV-ET (17.3 ± 1.7 mg/dL), p < 0.001. Need for repeated exchange transfusions was significantly lower in TSSV-ET group (13.5%), compared to 32.7% in SSDV-ET group, p < 0.05. No significant difference was found between the two groups as regards the morbidity (11.5% and 9.6%, respectively) and the mortality (1.9% for both groups). Two-stage single-volume exchange transfusion proved to be more effective in reducing rebound serum bilirubin level post-exchange and in decreasing the need for repeated exchange transfusions.

Theoretical and experimental investigations on the cooling capacity distributions at the stages in the thermally-coupled two-stage Stirling-type pulse tube cryocooler without external precooling

Science.gov (United States)

Tan, Jun; Dang, Haizheng

2017-03-01

The two-stage Stirling-type pulse tube cryocooler (SPTC) has advantages in simultaneously providing the cooling powers at two different temperatures, and the capacity in distributing these cooling capacities between the stages is significant to its practical applications. In this paper, a theoretical model of the thermally-coupled two-stage SPTC without external precooling is established based on the electric circuit analogy with considering real gas effects, and the simulations of both the cooling performances and PV power distribution between stages are conducted. The results indicate that the PV power is inversely proportional to the acoustic impedance of each stage, and the cooling capacity distribution is determined by the cold finger cooling efficiency and the PV power into each stage together. The design methods of the cold fingers to achieve both the desired PV power and the cooling capacity distribution between the stages are summarized. The two-stage SPTC is developed and tested based on the above theoretical investigations, and the experimental results show that it can simultaneously achieve 0.69 W at 30 K and 3.1 W at 85 K with an electric input power of 330 W and a reject temperature of 300 K. The consistency between the simulated and the experimental results is observed and the theoretical investigations are experimentally verified.

Single-stage micro-scale solvent extraction in parallel microbore tubes using MDIMJ

International Nuclear Information System (INIS)

Darekar, Mayur; Singh, K.K.; Joshi, J.M.; Mukhopadhyay, S.; Shenoy, K.T.

2016-01-01

Single-stage micro-scale solvent extraction of U(VI) from simulated lean streams is explored using micro-scale contactor comprising of a MDIMJ (Monoblock Distributor with Integrated Microfluidic Junction) and PTFE microbore tubes. 30% (v/v) TBP in dodecane has been used as the extracting phase. The objective of the study is to demonstrate numbering up approach for scale-up of micro-scale extraction using indigenously conceptualized and fabricated MDIMJ. First the performance of MIDIMJ for equal flow distribution is tested. Then the effects of inlet flow rate and O/A ratio on stage efficiency and percentage extraction are studied. The experiments show that it is easy to scale-up single-stage micro-scale solvent extraction by using MDIMJ for numbering up approach. Maximum capacity tested is 4.8 LPH. With O/A = 2/1, more than 90% extraction is achieved in a very short contact time of less than 3s. The study thus demonstrates possibility of process intensification and easy scale-up of micro-scale solvent extraction

Experimental study on two-stage compression refrigeration/heat pump system with dual-cylinder rolling piston compressor

International Nuclear Information System (INIS)

Shuxue, Xu; Guoyuan, Ma

2014-01-01

A thermodynamically analytical model on the two-stage compression refrigeration/heat pump system with vapor injection was derived. The optimal volume ratio of the high-pressure cylinder to the low-pressure one has been discussed under both cooling and heating conditions. Based on the above research, the prototype was developed and its experimental setup established. A comprehensive experiments for the prototype have been conducted, and the results show that, compared with the single-stage compression heat pump system, the cooling capacity and cooling COP can increase 5%–15% and 10–12%, respectively. Also, the heating capacity with the evaporating temperature ranging from 0.3 to 3 °C is 92–95% of that under the rate condition with the evaporating temperature of 7 °C, and 58% when the evaporation temperature is between −28 °C and −24 °C. -- Highlights: • The volume ratio of the compressor is between 0.65 and 0.78 and the relative vapor injection mass ranges from 15% to 20%. • The cooling capacity and COP of the two-stage compression system can improve 5%–15% and 10%–12%. • The heating capacity can also be improved under low temperature condition

Analysis of honeybush tea (Cyclopia spp.) volatiles by comprehensive two-dimensional gas chromatography using a single-stage thermal modulator.

Science.gov (United States)

Ntlhokwe, Gaalebalwe; Tredoux, Andreas G J; Górecki, Tadeusz; Edwards, Matthew; Vestner, Jochen; Muller, Magdalena; Erasmus, Lené; Joubert, Elizabeth; Christel Cronje, J; de Villiers, André

2017-07-01

The applicability of comprehensive two-dimensional gas chromatography (GC×GC) using a single-stage thermal modulator was explored for the analysis of honeybush tea (Cyclopia spp.) volatile compounds. Headspace solid phase micro-extraction (HS-SPME) was used in combination with GC×GC separation on a non-polar × polar column set with flame ionisation (FID) detection for the analysis of fermented Cyclopia maculata, Cyclopia subternata and Cyclopia genistoides tea infusions of a single harvest season. Method optimisation entailed evaluation of the effects of several experimental parameters on the performance of the modulator, the choice of columns in both dimensions, as well as the HS-SPME extraction fibre. Eighty-four volatile compounds were identified by co-injection of reference standards. Principal component analysis (PCA) showed clear differentiation between the species based on their volatile profiles. Due to the highly reproducible separations obtained using the single-stage thermal modulator, multivariate data analysis was simplified. The results demonstrate both the complexity of honeybush volatile profiles and the potential of GC×GC separation in combination with suitable data analysis techniques for the investigation of the relationship between sensory properties and volatile composition of these products. The developed method therefore offers a fast and inexpensive methodology for the profiling of honeybush tea volatiles. Graphical abstract Surface plot obtained for the GC×GC-FID analysis of honeybush tea volatiles.

Callus Distraction Versus Single-Stage Lengthening With Bone Graft for Treatment of Brachymetatarsia: A Systematic Review.

Science.gov (United States)

Jones, Marc D; Pinegar, David M; Rincker, Sarah A

2015-01-01

Brachymetatarsia deformity is a cosmetically displeasing anomaly that can become physically symptomatic. The surgical techniques most commonly used to repair the anomaly include single-stage lengthening with a bone graft, callus distraction, or a combination of bone grafting and callus distraction. A systematic review of the published data was performed to compare the outcomes of these 3 surgical procedures. A total of 61 studies reporting the use of callus distraction or single-stage lengthening, or both, for the treatment of brachymetatarsia were included in the present review. The incidence of major postoperative complications after callus distraction, single-stage lengthening, and the combination procedure was 49 (12.62%), 13 (3.72%), and 3 (33.33%), respectively. The number of minor complications with callus distraction, single-stage lengthening, and the combination procedure was 152 (39.18%), 55 (15.76%), and 1 (11.11%); the mean percentage of the original length achieved was 37.36%, 25.98% and 36.00%; and the mean length achieved was 17.5, 13.2, and 14.0 mm, respectively. The healing index (mo/cm) and healing time was 2.31 and 16.04 weeks, 1.90 and 9.35 weeks, and 3.93 and 14.62 weeks for callus distraction, single-stage lengthening, and the combination procedure, respectively. Our findings indicate that the callus distraction technique is associated with greater length gained but results in greater complication rates and requires almost twice the time to heal. Single-stage lengthening with a bone graft was associated with fewer complications and faster healing times than callus distraction but with lesser gains in length. From the information reported in the studies we reviewed, the prevalence of bilateral brachymetatarsia was 44.52%, and the female/male ratio was 13.7:1. Both of these findings seem to contradict the usual data given (72% for bilateral brachymetatarsia and a female/male ratio of 25:1). Copyright © 2015 American College of Foot and

Determination of blade-to-coolant heat-transfer coefficients on a forced-convection, water-cooled, single-stage turbine

Science.gov (United States)

Freche, John C; Schum, Eugene F

1951-01-01

Blade-to-coolant convective heat-transfer coefficients were obtained on a forced-convection water-cooled single-stage turbine over a large laminar flow range and over a portion of the transition range between laminar and turbulent flow. The convective coefficients were correlated by the general relation for forced-convection heat transfer with laminar flow. Natural-convection heat transfer was negligible for this turbine over the Grashof number range investigated. Comparison of turbine data with stationary tube data for the laminar flow of heated liquids showed good agreement. Calculated average midspan blade temperatures using theoretical gas-to-blade coefficients and blade-to-coolant coefficients from stationary-tube data resulted in close agreement with experimental data.

Fill Rates of Single-Stage and Multistage Supply Systems

OpenAIRE

Matthew J. Sobel

2004-01-01

A supply system's fill rate is the fraction of demand that is met from on-hand inventory. This paper presents formulas for the fill rate of periodic review supply systems that use base-stock-level policies. The first part of the paper contains fill-rate formulas for a single-stage system and general distributions of demand. When demand is normally distributed, an exact expression uses only the standard normal distribution and density functions, and a good approximation uses only the standard ...

Single Stage String Inverter for Gridconnected Photovoltaic System with Modified Perturb and Observe (P&O Fuzzy Logic Control(FLC-based MPPT Technique

Directory of Open Access Journals (Sweden)

S.Z.Mohammad Noor

2016-06-01

Full Text Available This paper presents an implementation of Single-phase Single stage String inverter for Grid connected Photovoltaic (PV system. The proposed system uses Modified Perturb and Observe (P&O algorithm implemented using Fuzzy Logic Control (FLC as Maximum Power Point Tracking (MPPT. The inverter is designed for 340W system using two series of STP170s24/Ac PV modules. The MPPT unit keeps tracking the maximum power from the PV array by changing the modulation index and the phase angle of inverter’s output voltage. The simulation model is developed using Matlab/Simulink to evaluate the performance of the converter. Selected experimental results are also presented in this paper.

High peak-power kilohertz laser system employing single-stage multi-pass amplification

Science.gov (United States)

Shan, Bing; Wang, Chun; Chang, Zenghu

2006-05-23

The present invention describes a technique for achieving high peak power output in a laser employing single-stage, multi-pass amplification. High gain is achieved by employing a very small "seed" beam diameter in gain medium, and maintaining the small beam diameter for multiple high-gain pre-amplification passes through a pumped gain medium, then leading the beam out of the amplifier cavity, changing the beam diameter and sending it back to the amplifier cavity for additional, high-power amplification passes through the gain medium. In these power amplification passes, the beam diameter in gain medium is increased and carefully matched to the pump laser's beam diameter for high efficiency extraction of energy from the pumped gain medium. A method of "grooming" the beam by means of a far-field spatial filter in the process of changing the beam size within the single-stage amplifier is also described.

Theoretical evaluation of the efficiency of gas single-stage reciprocating compressor medium pressure units

Science.gov (United States)

Busarov, S. S.; Vasil'ev, V. K.; Busarov, I. S.; Titov, D. S.; Panin, Ju. N.

2017-08-01

Developed earlier and tested in such working fluid as air, the technology of calculating the operating processes of slow-speed long-stroke reciprocating stages let the authors to obtain successful results concerning compression of gases to medium pressures in one stage. In this connection, the question of the efficiency of the application of slow-speed long-stroke stages in various fields of technology and the national economy, where the working fluid is other gas or gas mixture, is topical. The article presents the results of the efficiency evaluation of single-stage compressor units on the basis of such stages for cases when ammonia, hydrogen, helium or propane-butane mixture is used as the working fluid.

Mass-transfer in extraction and reextraction as a single-stage process

International Nuclear Information System (INIS)

Rodriguez del Cerro, M.; Trilleros, J.A.; Otero de la Gandara, J.L.

1987-01-01

The rate of mass transfer between water and naftenic acid and threebutilphosphate in kerosen are studied in the two possibilities to or from water. The two insoluble phases are brought in to intimate contact with dispersed phase droplets, in a single-stage process. The evolution of the equilibrium distribution of solute is taken in consideration. (author)

Millijoule Pulse Energy Second Harmonic Generation With Single-Stage Photonic Bandgap Rod Fiber Laser

DEFF Research Database (Denmark)

Laurila, Marko; Saby, Julien; Alkeskjold, Thomas Tanggaard

2011-01-01

In this paper, we demonstrate, for the first time, a single-stage Q-switched single-mode (SM) ytterbium-doped rod fiber laser delivering record breaking pulse energies at visible and UV light. We use a photonic bandgap rod fiber with a mode field diameter of 59μm based on a new distributed...

A high-order positivity-preserving single-stage single-step method for the ideal magnetohydrodynamic equations

Science.gov (United States)

Christlieb, Andrew J.; Feng, Xiao; Seal, David C.; Tang, Qi

2016-07-01

We propose a high-order finite difference weighted ENO (WENO) method for the ideal magnetohydrodynamics (MHD) equations. The proposed method is single-stage (i.e., it has no internal stages to store), single-step (i.e., it has no time history that needs to be stored), maintains a discrete divergence-free condition on the magnetic field, and has the capacity to preserve the positivity of the density and pressure. To accomplish this, we use a Taylor discretization of the Picard integral formulation (PIF) of the finite difference WENO method proposed in Christlieb et al. (2015) [23], where the focus is on a high-order discretization of the fluxes (as opposed to the conserved variables). We use the version where fluxes are expanded to third-order accuracy in time, and for the fluid variables space is discretized using the classical fifth-order finite difference WENO discretization. We use constrained transport in order to obtain divergence-free magnetic fields, which means that we simultaneously evolve the magnetohydrodynamic (that has an evolution equation for the magnetic field) and magnetic potential equations alongside each other, and set the magnetic field to be the (discrete) curl of the magnetic potential after each time step. In this work, we compute these derivatives to fourth-order accuracy. In order to retain a single-stage, single-step method, we develop a novel Lax-Wendroff discretization for the evolution of the magnetic potential, where we start with technology used for Hamilton-Jacobi equations in order to construct a non-oscillatory magnetic field. The end result is an algorithm that is similar to our previous work Christlieb et al. (2014) [8], but this time the time stepping is replaced through a Taylor method with the addition of a positivity-preserving limiter. Finally, positivity preservation is realized by introducing a parameterized flux limiter that considers a linear combination of high and low-order numerical fluxes. The choice of the free

The Integrity of ACSR Full Tension Single-Stage Splice Connector at Higher Operation Temperature

Energy Technology Data Exchange (ETDEWEB)

Wang, Jy-An John [ORNL; Lara-Curzio, Edgar [ORNL; King Jr, Thomas J [ORNL

2008-10-01

Due to increases in power demand and limited investment in new infrastructure, existing overhead power transmission lines often need to operate at temperatures higher than those used for the original design criteria. This has led to the accelerated aging and degradation of splice connectors. It is manifested by the formation of hot-spots that have been revealed by infrared imaging during inspection. The implications of connector aging is two-fold: (1) significant increases in resistivity of the splice connector (i.e., less efficient transmission of electricity) and (2) significant reductions in the connector clamping strength, which could ultimately result in separation of the power transmission line at the joint. Therefore, the splice connector appears to be the weakest link in electric power transmission lines. This report presents a protocol for integrating analytical and experimental approaches to evaluate the integrity of full tension single-stage splice connector assemblies and the associated effective lifetime at high operating temperature.

Stall inception and warning in a single-stage transonic axial compressor with axial skewed slot casing treatment

International Nuclear Information System (INIS)

Lim, Byeung Jun; Kwon, Se Jin; Park, Tae Choon

2014-01-01

Characteristic changes in the stall inception in a single-stage transonic axial compressor with an axial skewed slot casing treatment were investigated experimentally. A rotating stall occurred intermittently in a compressor with an axial skewed slot, whereas spike-type rotating stalls occurred in the case of smooth casing. The axial skewed slot suppressed stall cell growth and increased the operating range. A mild surge, the frequency of which is the Helmholtz frequency of the compressor system, occurred with the rotating stall. The irregularity in the pressure signals at the slot bottom increased decreasing flow rate. An autocorrelation-based stall warning method was applied to the measured pressure signals. Results estimate and warn against the stall margin in a compressor with an axial skewed slot.

Numerical and experimental modelling of the centrifugal compressor stage - setting the model of impellers with 2D blades

Science.gov (United States)

Matas, Richard; Syka, Tomáš; Luňáček, Ondřej

The article deals with a description of results from research and development of a radial compressor stage. The experimental compressor and used numerical models are briefly described. In the first part, the comparisons of characteristics obtained experimentally and by numerical simulations for stage with vaneless diffuser are described. In the second part, the results for stage with vanned diffuser are presented. The results are relevant for next studies in research and development process.

Wind-driven SEIG supplying DC microgrid through a single-stage power converter

Directory of Open Access Journals (Sweden)

Vellapatchi Nayanar

2016-09-01

Full Text Available Nowadays, there is an increased emphasis on utilizing the renewable energy sources and selection of suitable power converters for supplying dc microgrid. Among the various renewable energy sources, wind energy stands first in terms of installed capacity. So, an attempt is made in this paper for supplying dc microgrid utilizing wind energy. A self-excited induction generator has been used in the proposed wind energy conversion system (WECS. A single-stage power converter, namely, semi-converter is connected between the SEIG and dc grid terminals for closed-loop control of the proposed system. A perturb and observe (P&O based maximum power point tracking (MPPT algorithm has been developed and implemented using a dsPIC30F4011 digital controller. In this MPPT algorithm, the firing angle of the converter is adjusted by continuously monitoring the dc grid current for a given wind velocity. For analyzing the proposed system, a MATLAB/Simulink model has been developed by selecting the various components starting from wind-turbine model to the power converter supplying dc microgrid. Successful working of the proposed WECS has also been shown through experimental results obtained on a prototype model developed in the laboratory.

Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation in surgical treatment for single-segment lumbar spinal tuberculosis.

Science.gov (United States)

Zeng, Hao; Wang, Xiyang; Zhang, Penghui; Peng, Wei; Liu, Zheng; Zhang, Yupeng

2015-01-01

The aim of this study is to determine the feasibility and efficacy of surgical management of single-segment lumbar spinal tuberculosis (TB) by using single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation. Seventeen cases of single-segment lumbar TB were treated with single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation. The mean follow-up was 36.9 months (range: 24-62 months). The kyphotic angle ranged from 15.2-35.1° preoperatively, with an average measurement of 27.8°. The American Spinal Injury Association (ASIA) score system was used to evaluate the neurological deficits and erythrocyte sedimentation rate (ESR) used to judge the activity of TB. Spinal TB was completely cured in all 17 patients. There was no recurrent TB infection. The postoperative kyphotic angle was 6.6-10.2°, 8.1° in average, and there was no significant loss of the correction at final follow-up. Solid fusion was achieved in all cases. Neurological condition in all patients was improved after surgery. Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation can be a feasible and effective method the in treatment of single-segment lumbar spinal TB.

Automatic sleep stage classification of single-channel EEG by using complex-valued convolutional neural network.

Science.gov (United States)

Zhang, Junming; Wu, Yan

2018-03-28

Many systems are developed for automatic sleep stage classification. However, nearly all models are based on handcrafted features. Because of the large feature space, there are so many features that feature selection should be used. Meanwhile, designing handcrafted features is a difficult and time-consuming task because the feature designing needs domain knowledge of experienced experts. Results vary when different sets of features are chosen to identify sleep stages. Additionally, many features that we may be unaware of exist. However, these features may be important for sleep stage classification. Therefore, a new sleep stage classification system, which is based on the complex-valued convolutional neural network (CCNN), is proposed in this study. Unlike the existing sleep stage methods, our method can automatically extract features from raw electroencephalography data and then classify sleep stage based on the learned features. Additionally, we also prove that the decision boundaries for the real and imaginary parts of a complex-valued convolutional neuron intersect orthogonally. The classification performances of handcrafted features are compared with those of learned features via CCNN. Experimental results show that the proposed method is comparable to the existing methods. CCNN obtains a better classification performance and considerably faster convergence speed than convolutional neural network. Experimental results also show that the proposed method is a useful decision-support tool for automatic sleep stage classification.

Adaptive kanban control mechanism for a single-stage hybrid system

Science.gov (United States)

Korugan, Aybek; Gupta, Surendra M.

2002-02-01

In this paper, we consider a hybrid manufacturing system with two discrete production lines. Here the output of either production line can satisfy the demand for the same type of product without any penalties. The interarrival times for demand occurrences and service completions are exponentially distributed i.i.d. variables. In order to control this type of manufacturing system we suggest a single stage pull type control mechanism with adaptive kanbans and state independent routing of the production information.

Disturbance estimation and compensation for planar motors on the long-stroke stage of a wafer stage

Directory of Open Access Journals (Sweden)

Bizhong Xia

2015-04-01

Full Text Available This article presents a data-based method to estimate and compensate low-frequency disturbance in planar motors on the long-stroke stage of a wafer stage, which is a typical multiple-input multiple-output system. First, a data-based method is introduced to decouple the multiple-input multiple-output system into multi-single-input single-output system, which is crucial for the design of controller and the correction of disturbance estimation in the scanning direction. Second, dominant low-frequency disturbances in the long-stroke stage are analyzed. Third, estimation and compensation method under moving condition is proposed. The compensation method is based on three feedforward tables, and the tables are indexed by trajectory parameters, including velocity and position instead of time in the iterative learning control method. Finally, experiments are performed on the long-stroke stage of a wafer stage to verify the proposed method. Experimental results show that the proposed method can effectively improve the servo performance by reducing the tracking errors by nearly 1/2 in the forward direction and 1/3 in the backward direction and lowering error difference between the forward and backward directions from 5.1 to 1.2 µm.

New current control based MPPT technique for single stage grid connected PV systems

International Nuclear Information System (INIS)

Jain, Sachin; Agarwal, Vivek

2007-01-01

This paper presents a new maximum power point tracking algorithm based on current control for a single stage grid connected photovoltaic system. The main advantage of this algorithm comes from its ability to predict the approximate amplitude of the reference current waveform or power that can be derived from the PV array with the help of an intermediate variable β. A variable step size for the change in reference amplitude during initial tracking helps in fast tracking. It is observed that if the reference current amplitude is greater than the array capacity, the system gets unstable (i.e. moves into the positive slope region of the p-v characteristics of the array). The proposed algorithm prevents the PV system from entering the positive slope region of the p-v characteristics. It is also capable of restoring stability if the system goes unstable due to a sudden environmental change. The proposed algorithm has been tested on a new single stage grid connected PV configuration recently developed by the authors to feed sinusoidal current into the grid. The system is operated in a continuous conduction mode to realize advantages such as low device current stress, high efficiency and low EMI. A fast MPPT tracker with single stage inverter topology operating in CCM makes the overall system highly efficient. Specific cases of the system, operating in just discontinuous current mode and discontinuous current mode and their relative merits and demerits are also discussed

Compressed gas combined single- and two-stage light-gas gun

Science.gov (United States)

Lamberson, L. E.; Boettcher, P. A.

2018-02-01

With more than 1 trillion artificial objects smaller than 1 μm in low and geostationary Earth orbit, space assets are subject to the constant threat of space debris impact. These collisions occur at hypervelocity or speeds greater than 3 km/s. In order to characterize material behavior under this extreme event as well as study next-generation materials for space exploration, this paper presents a unique two-stage light-gas gun capable of replicating hypervelocity impacts. While a limited number of these types of facilities exist, they typically are extremely large and can be costly and dangerous to operate. The design presented in this paper is novel in two distinct ways. First, it does not use a form of combustion in the first stage. The projectile is accelerated from a pressure differential using air and inert gases (or purely inert gases), firing a projectile in a nominal range of 1-4 km/s. Second, the design is modular in that the first stage sits on a track sled and can be pulled back and used in itself to study lower speed impacts without any further modifications, with the first stage piston as the impactor. The modularity of the instrument allows the ability to investigate three orders of magnitude of impact velocities or between 101 and 103 m/s in a single, relatively small, cost effective instrument.

Reactive Power Control of Single-Stage Three-Phase Photovoltaic System during Grid Faults Using Recurrent Fuzzy Cerebellar Model Articulation Neural Network

Directory of Open Access Journals (Sweden)

Faa-Jeng Lin

2014-01-01

Full Text Available This study presents a new active and reactive power control scheme for a single-stage three-phase grid-connected photovoltaic (PV system during grid faults. The presented PV system utilizes a single-stage three-phase current-controlled voltage-source inverter to achieve the maximum power point tracking (MPPT control of the PV panel with the function of low voltage ride through (LVRT. Moreover, a formula based on positive sequence voltage for evaluating the percentage of voltage sag is derived to determine the ratio of the injected reactive current to satisfy the LVRT regulations. To reduce the risk of overcurrent during LVRT operation, a current limit is predefined for the injection of reactive current. Furthermore, the control of active and reactive power is designed using a two-dimensional recurrent fuzzy cerebellar model articulation neural network (2D-RFCMANN. In addition, the online learning laws of 2D-RFCMANN are derived according to gradient descent method with varied learning-rate coefficients for network parameters to assure the convergence of the tracking error. Finally, some experimental tests are realized to validate the effectiveness of the proposed control scheme.

The Incidence of Complications in Single-stage Endoscopic Stone Removal for Patients with Common Bile Duct Stones: A Propensity Score Analysis.

Science.gov (United States)

Saito, Hirokazu; Kadono, Yoshihiro; Kamikawa, Kentaro; Urata, Atsushi; Imamura, Haruo; Matsushita, Ikuo; Kakuma, Tatsuyuki; Tada, Shuji

2018-02-15

Objective Single-stage endoscopic stone removal for choledocholithiasis is an advantageous approach because it is associated with a shorter hospital stay; however, few studies have reported the incidence of complications related to this procedure in detail. The aim of this study was to examine the incidence of complications and efficacy of this procedure. Methods This retrospective study investigated the incidence of complications in 345 patients with naive papilla who underwent therapeutic endoscopic retrograde cholangiopancreatography (ERCP) for choledocholithiasis at three institutions between April 2014 and March 2016 by a propensity score analysis. The efficacy of single-stage endoscopic stone removal was assessed based on a hospital stay of within 7 days and the number of ERCP attempts. Results Among 114 patients who underwent single-stage endoscopic stone removal, 15 patients (13.2%) experienced complications. Among the remaining 231 patients in the two-stage endoscopic stone removal group, complications were observed in 17 patients (7.4%). The propensity score analysis, which was adjusted for confounding factors, revealed that single-stage endoscopic stone removal was not a significant risk factor for complications (p=0.52). In patients in whom >10 min was required for deep cannulation, single-stage endoscopic stone removal was not a significant risk factor for complications in the propensity score analysis (p=0.37). In the single-stage group, the proportion of patients with a hospital stay of within 7 days was significantly higher and the number of ERCP attempts was significantly lower in comparison to the two-stage group (p <0.0001 and <0.0001, respectively). Conclusion Single-stage endoscopic stone removal did not increase the incidence of complications associated with ERCP and was effective for reducing the hospital stay and the number of ERCP attempts.

A tetrad of bicuspid aortic valve association: A single-stage repair

Science.gov (United States)

Barik, Ramachandra; Patnaik, A. N.; Mishra, Ramesh C.; Kumari, N. Rama; Gulati, A. S.

2012-01-01

We report a 27 years old male who presented with a combination of both congenital and acquired cardiac defects. This syndrome complex includes congenital bicuspid aortic valve, Seller's grade II aortic regurgitation, juxta- subclavian coarctation, stenosis of ostium of left subclavian artery and ruptured sinus of Valsalva aneurysm without any evidence of infective endocarditis. This type of constellation is extremely rare. Neither coarctation of aorta with left subclavian artery stenosis nor the rupture of sinus Valsalva had a favorable pathology for percutaneus intervention. Taking account into morbidity associated with repeated surgery and anesthesia patient underwent a single stage surgical repair of both the defects by two surgical incisions. The approaches include median sternotomy for rupture of sinus of Valsalva and lateral thoracotomy for coarctation with left subclavian artery stenosis. The surgery was uneventful. After three months follow up echocardiography showed mild residual gradient across the repaired coarctation segment, mild aortic regurgitation and no residual left to right shunt. This patient is under follow up. This is an extremely rare case of single stage successful repair of coarctation and rupture of sinus of Valsalva associated with congenital bicuspid aortic valve. PMID:22629035

Large Conization and Laparoendoscopic Single-Port Pelvic Lymphadenectomy in Early-Stage Cervical Cancer for Fertility Preservation

Directory of Open Access Journals (Sweden)

Polat Dursun

2013-01-01

Full Text Available Fertility preservation in early-stage cervical cancer is a hot topic in gynecologic oncology. Although radical vaginal trachelectomy (RVT is suggested as a fertility preserving approach, there are some serious concerns like cervical stenosis, second trimester loss, preterm delivery in survivors, and lack of residual tumor in the majority of the surgical specimens. Therefore, less radical surgical operations have been proposed in early-stage cervical carcinomas. On the other hand, single-incision laparoscopic surgery (SILS is an evolving endoscopic approach for minimal access surgery. In this report, we present a case with early-stage cervical cancer who wishes to preserve fertility. We successfully performed single-port pelvic lymphadenectomy and large conization to preserve fertility potential of the patient. We think that combination of less radical approach like conization and single-port pelvic lymphadenectomy might be less minimally invasive and is still an effective surgical approach in well-selected cases with cervical carcinomas. Incorporation of single-port laparoscopy into the minimally invasive fertility sparing management of the cervical cancer will improve patients outcome with less complications and better cosmesis. Further studies are needed to reach a clear conclusion.

experimental implementation of single-phase, three-level, sinusoidal

African Journals Online (AJOL)

Page 1 ... of many multilevel inverter configurations. This paper presents an experimental report of a simplified topology for single-phase, SPWM, three-level voltage source inverter wit R-L load. To keep the power circuit ... employed in many industrial applications such as variable speed drives, uninterruptible power sup-.

Grid Integration of Single Stage Solar PV System using Three-level Voltage Source Converter

Science.gov (United States)

Hussain, Ikhlaq; Kandpal, Maulik; Singh, Bhim

2016-08-01

This paper presents a single stage solar PV (photovoltaic) grid integrated power generating system using a three level voltage source converter (VSC) operating at low switching frequency of 900 Hz with robust synchronizing phase locked loop (RS-PLL) based control algorithm. To track the maximum power from solar PV array, an incremental conductance algorithm is used and this maximum power is fed to the grid via three-level VSC. The use of single stage system with three level VSC offers the advantage of low switching losses and the operation at high voltages and high power which results in enhancement of power quality in the proposed system. Simulated results validate the design and control algorithm under steady state and dynamic conditions.

The pathogenesis of single experimental infections with Strongylus vulgaris in foals.

Science.gov (United States)

Duncan, J L; Pirie, H M

1975-01-01

The clinical signs, pathology and clinical pathology associated with single experimental infections of Strongylus vulgaris in worm-free pony foals are described. The major clinical signs which became apparent in the infected foals during the first three weeks were pyrexia, anorexia, dullness and abdominal pain. Within the first two weeks of infection lesions were confined to the intestine and terminal branches of the intestinal arteries and consisted of mucosal, submucosal and serosal haemorrhage together with arteritis of submucosal and serosal arteries and also a marked inflammatory reaction. The main lesion seen three weeks after infection was gross thrombosis of the anterior mesenteric artery or one of its major branches. On section these affected arteries showed marked intimal thickening with infiltration of plasma cells, lymphocytes, macrophages and neutrophils. Between one and four months after infection the gross lesions were predominantly in the arteries and consisted of fibrous thickening of the arterial wall and thrombosis associated with the presence of developing fourth stage larvae. Four months after infection the arterial lesions were still prominent and microscopically there was fibrosis of the wall of the affected artery with wide-spread disruption of the intima. In the adventitia organised thrombi were apparent in the vasa vasorum and resulted in the obliteration of their lumina. The typical lesion associated with the return of fifth stage larvae to the intestine was nodule formation in close proximity to thrombosed terminal intestinal arteries and sections of parasites were seen in the intestinal wall surrounded by neutrophils and necrotic debris. By nine months after infection the arterial lesion had healed, but histologically there was fibrosis of the intima and macrophages containing haemosiderin were seen in the arterial wall. The most significant haematological findings during the experimental period were a marked polymorphonuclear

Experimental study and numerical simulation of the plastic deformation of zirconium single crystals

International Nuclear Information System (INIS)

Lebon, C.

2011-01-01

There is only few experimental data in the literature on the zirconium single crystals and no constitutive laws for this single crystal material are provided. The goal of this work is then to create an experimental database like the Critical Resolved Shear Stress (CRSS) for the prismatic slip, the strain-hardening, the activation of the prismatic glide system and the activation volumes. We determine theses parameters from image correlation method. Then, we develop a new multi-scale approach using dislocations dynamics concept and finite element computations. Finally, a first single crystal constitutive law for the zirconium is proposed and a good agreement with the experimental data is obtained. (author) [fr

Attainability and minimum energy of single-stage membrane and membrane/distillation hybrid processes

KAUST Repository

Alshehri, Ali

2014-12-01

As an energy-efficient separation method, membrane technology has attracted more and more attentions in many challenging separation processes. The attainability and the energy consumption of a membrane process are the two basic fundamental questions that need to be answered. This report aims to use process simulations to find: (1) at what conditions a single-stage membrane process can meet the separation task that is defined by product purity and recovery ratio and (2) what are the most important parameters that determine the energy consumption. To perform a certain separation task, it was found that both membrane selectivity and pressure ratio exhibit a minimum value that is defined only by product purity and recovery ratio. The membrane/distillation hybrid system was used to study the energy consumption. A shortcut method was developed to calculate the minimum practical separation energy (MPSE) of the membrane process and the distillation process. It was found that the MPSE of the hybrid system is only determined by the membrane selectivity and the applied transmembrane pressure ratio in three stages. At the first stage when selectivity is low, the membrane process is not competitive to the distillation process. Adding a membrane unit to a distillation tower will not help in reducing energy. At the second medium selectivity stage, the membrane/distillation hybrid system can help reduce the energy consumption, and the higher the membrane selectivity, the lower is the energy. The energy conservation is further improved as pressure ratio increases. At the third stage when both selectivity and pressure ratio are high, the hybrid system will change to a single-stage membrane unit and this change will cause significant reduction in energy consumption. The energy at this stage keeps decreasing with selectivity at slow rate, but slightly increases with pressure ratio. Overall, the higher the membrane selectivity, the more the energy is saved. Therefore, the two

Fueling of magnetically confined plasmas by single- and two-stage repeating pneumatic pellet injectors

International Nuclear Information System (INIS)

Gouge, M.J.; Combs, S.K.; Foust, C.R.; Milora, S.L.

1990-01-01

Advanced plasma fueling systems for magnetic fusion confinement experiments are under development at Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogenic pellets to speeds in the kilometer-per-second range using single shot and repetitive pneumatic (light-gas gun) pellet injectors. The millimeter-to-centimeter size pellets enter the plasma and continuously ablate because of the plasma electron heat flux, depositing fuel atoms along the pellet trajectory. This fueling method allows direct fueling in the interior of the hot plasma and is more efficient than the alternative method of injecting room temperature fuel gas at the wall of the plasma vacuum chamber. Single-stage pneumatic injectors based on the light-gas gun concept have provided hydrogenic fuel pellets in the speed range of 1--2 km/s in single-shot injector designs. Repetition rates up to 5 Hz have been demonstrated in repetitive injector designs. Future fusion reactor-scale devices may need higher pellet velocities because of the larger plasma size and higher plasma temperatures. Repetitive two-stage pneumatic injectors are under development at ORNL to provide long-pulse plasma fueling in the 3--5 km/s speed range. Recently, a repeating, two-stage light-gas gun achieved repetitive operation at 1 Hz with speeds in the range of 2--3 km/s

A numerical investigation on the unstable flow in a single stage of an axial compressors

CERN Document Server

Farhanieh, B; Ghorbanian, K

2003-01-01

An unsteady two-dimensional finite-volume solver was developed based on Van Leer's flux splitting algorithm in conjunction with sup M onotonic Upstream Scheme for Conservation Laws sup l imiters to improve the order of accuracy and the two-layer Baldwin-Lomax turbulence model was also implemented. Two test cases were prepared to validate the solver. The computed results were compared with the experimental data and a good agreement validated the solver. Finally, the solver was used for the flow through a multi-blade stage of an axial compressor in its off-design condition. The computed results showed a rotating stall-like instability with a periodic behavior. To investigate the flow properties during the instability condition, the flow pattern, vortex properties and the axial velocity were studied. It was concluded that the instability vortices in the multi-blade cascade do not have the same generation history of the separated vortices over a single body.

Temperature-phased anaerobic digestion of food waste: A comparison with single-stage digestions based on performance and energy balance.

Science.gov (United States)

Xiao, Benyi; Qin, Yu; Zhang, Wenzhe; Wu, Jing; Qiang, Hong; Liu, Junxin; Li, Yu-You

2018-02-01

The temperature-phased anaerobic digestion (TPAD) of food waste was studied for the purpose of comparing with single-stage mesophilic and thermophilic anaerobic digestion. The biogas and methane yields in the TPAD during the steady period were 0.759 ± 0.115 L/g added VS and 0.454 ± 0.201 L/g added VS, which were lower than those in the two single-stage anaerobic digestion. The improper sludge retention time may be the reason for the lower biogas and methane production in TPAD. The removal of volatile solids in the TPAD was 78.55 ± 4.59% and the lowest among the three anaerobic digestion processes. The reaction ratios of the four anaerobic digestion steps in the TPAD were all lower than those in the two single-stage anaerobic digestion. The energy conversion efficiency of the degraded substrate in the TPAD was similar with those in single-stage mesophilic and thermophilic anaerobic digestion systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Numerical and experimental modelling of the centrifugal compressor stage – setting the model of impellers with 2D blades

Directory of Open Access Journals (Sweden)

Matas Richard

2017-01-01

Full Text Available The article deals with a description of results from research and development of a radial compressor stage. The experimental compressor and used numerical models are briefly described. In the first part, the comparisons of characteristics obtained experimentally and by numerical simulations for stage with vaneless diffuser are described. In the second part, the results for stage with vanned diffuser are presented. The results are relevant for next studies in research and development process.

Hydrodeoxygenation of oils from cellulose in single and two-stage hydropyrolysis

Energy Technology Data Exchange (ETDEWEB)

Rocha, J.D.; Snape, C.E. [Strathclyde Univ., Glasgow (United Kingdom); Luengo, C.A. [Universidade Estadual de Campinas, SP (Brazil). Dept. de Fisica Aplicada

1996-09-01

To investigate the removal of oxygen (hydrodeoxygenation) during the hydropyrolysis of cellulose, single and two-stage experiments on pure cellulose have been carried out using hydrogen pressures up to 10 MPa and temperatures over the range 300-520{sup o}C. Carbon, oxygen and aromaticity balances have been determined from the product yields and compositions. For the two-stage tests, the primary oils were passed through a bed of commercial Ni/Mo {gamma}-alumina-supported catalyst (Criterion 424, presulphided) at 400{sup o}C. Raising the hydrogen pressure from atmospheric to 10 MPa increased the carbon conversion by 10 mole % which was roughly equally divided between the oil and hydrocarbon gases. The oxygen content of the primary oil was reduced by over 10% to below 20% w/w. The addition of a dispersed iron sulphide catalyst further increased the oil yield at 10 MPa and reduces the oxygen content of the oil by a further 10%. The effect of hydrogen pressure on oil yields was most pronounced at low flow rates where it is beneficial in helping to overcome diffusional resistances. Unlike the dispersed iron sulphide in the first stage, the use of the Ni-Mo catalyst in the second stage reduced both the oxygen content and aromaticity of the oils. (Author)

Effects of catecholamine agonists and antagonists on alcohol uptake in rats with different stages of experimental alcoholism

Energy Technology Data Exchange (ETDEWEB)

Burov, Yu V; Varov, A I

1985-02-01

The effects of various catecholamine agonists and antagonists on 15% ethanol ingestion by outbred albino rats were studied in relation to the stage of experimental alcoholism. In animals with stage I and II alcoholism, alcohol intake was most profoundly inhibited by administration of alpha-adrenoblockers (AA), klofelin, and alpha-methyl-DOPA (AMD), while L-DOPA and cocaine stimulated a significant increase in ethanol ingestion. In stage III alcoholism, both AA and L-DOPA depressed alcohol intake, while AMD and haloperidol had a stimulatory effect. It appears, therefore, that different neurochemical mechanisms are involved in alcohol dependence in different stages of experimental alcoholism in the rat. Furthermore, it seems evident that alpha-adrenergic receptors have a key function in maintaining alcohol dependence. In well-established physical dependence, the importance of the noradrenergic system seems to diminish and dopaminergic mechanisms appear to become predominant. Consequently, in the initial stages of alcoholism, agents which depress the noradrenergic system seem indicated, while at the stage of physical dependence agents which normalize noradrenergic mechanisms and depress dopaminergic mechanisms should be considered. 13 references.

Genomic Prediction of Single Crosses in the Early Stages of a Maize Hybrid Breeding Pipeline

Directory of Open Access Journals (Sweden)

Dnyaneshwar C. Kadam

2016-11-01

Full Text Available Prediction of single-cross performance has been a major goal of plant breeders since the beginning of hybrid breeding. Recently, genomic prediction has shown to be a promising approach, but only limited studies have examined the accuracy of predicting single-cross performance. Moreover, no studies have examined the potential of predicting single crosses among random inbreds derived from a series of biparental families, which resembles the structure of germplasm comprising the initial stages of a hybrid maize breeding pipeline. The main objectives of this study were to evaluate the potential of genomic prediction for identifying superior single crosses early in the hybrid breeding pipeline and optimize its application. To accomplish these objectives, we designed and analyzed a novel population of single crosses representing the Iowa Stiff Stalk synthetic/non-Stiff Stalk heterotic pattern commonly used in the development of North American commercial maize hybrids. The performance of single crosses was predicted using parental combining ability and covariance among single crosses. Prediction accuracies were estimated using cross-validation and ranged from 0.28 to 0.77 for grain yield, 0.53 to 0.91 for plant height, and 0.49 to 0.94 for staygreen, depending on the number of tested parents of the single cross and genomic prediction method used. The genomic estimated general and specific combining abilities showed an advantage over genomic covariances among single crosses when one or both parents of the single cross were untested. Overall, our results suggest that genomic prediction of single crosses in the early stages of a hybrid breeding pipeline holds great potential to redesign hybrid breeding and increase its efficiency.

Experimental Setups for Single Event Effect Studies

OpenAIRE

N. H. Medina; V. A. P. Aguiar; N. Added; F. Aguirre; E. L. A. Macchione; S. G. Alberton; M. A. G. Silveira; J. Benfica; F. Vargas; B. Porcher

2016-01-01

Experimental setups are being prepared to test and to qualify electronic devices regarding their tolerance to Single Event Effect (SEE). A multiple test setup and a new beam line developed especially for SEE studies at the São Paulo 8 UD Pelletron accelerator were prepared. This accelerator produces proton beams and heavy ion beams up to 107Ag. A Super conducting Linear accelerator, which is under construction, may fulfill all of the European Space Agency requirements to qualify electronic...

A two-phase inspection model for a single component system with three-stage degradation

International Nuclear Information System (INIS)

Wang, Huiying; Wang, Wenbin; Peng, Rui

2017-01-01

This paper presents a two-phase inspection schedule and an age-based replacement policy for a single plant item contingent on a three-stage degradation process. The two phase inspection schedule can be observed in practice. The three stages are defined as the normal working stage, low-grade defective stage and critical defective stage. When an inspection detects that an item is in the low-grade defective stage, we may delay the preventive replacement action if the time to the age-based replacement is less than or equal to a threshold level. However, if it is above this threshold level, the item will be replaced immediately. If the item is found in the critical defective stage, it is replaced immediately. A hybrid bee colony algorithm is developed to find the optimal solution for the proposed model which has multiple decision variables. A numerical example is conducted to show the efficiency of this algorithm, and simulations are conducted to verify the correctness of the model. - Highlights: • A two-phase inspection model is studied. • The failure process has three stages. • The delayed replacement is considered.

Experimental research on single phase convection heat transfer in micro-fin tube

International Nuclear Information System (INIS)

Fan Guangming; Sun Zhongning; Zhu Sheng

2011-01-01

An experimental investigation of heat transfer and flow resistance characteristics of single phase water in three micro-fin tubes with different fin height was conducted. At the same time, the efficiency of micro-fin tubes within the experimental scope was evaluated and the optimal working region was determined. Based on the experimental data in the optimal working region, correlations for predicting the heat transfer and flow resistance were also given by multiple regression method. The result indicates that the micro-fin tubes can greatly enhance the single-phase heat transfer in turbulent flow, and the increase of heat transfer coefficient is higher than the increase of flow resistance. The accuracy of the correlation is very high, of which the deviation from the experimental value is very small. (authors)

Plasma gasification of refuse derived fuel in a single-stage system using different gasifying agents.

Science.gov (United States)

Agon, N; Hrabovský, M; Chumak, O; Hlína, M; Kopecký, V; Masláni, A; Bosmans, A; Helsen, L; Skoblja, S; Van Oost, G; Vierendeels, J

2016-01-01

The renewable evolution in the energy industry and the depletion of natural resources are putting pressure on the waste industry to shift towards flexible treatment technologies with efficient materials and/or energy recovery. In this context, a thermochemical conversion method of recent interest is plasma gasification, which is capable of producing syngas from a wide variety of waste streams. The produced syngas can be valorized for both energetic (heat and/or electricity) and chemical (ammonia, hydrogen or liquid hydrocarbons) end-purposes. This paper evaluates the performance of experiments on a single-stage plasma gasification system for the treatment of refuse-derived fuel (RDF) from excavated waste. A comparative analysis of the syngas characteristics and process yields was done for seven cases with different types of gasifying agents (CO2+O2, H2O, CO2+H2O and O2+H2O). The syngas compositions were compared to the thermodynamic equilibrium compositions and the performance of the single-stage plasma gasification of RDF was compared to that of similar experiments with biomass and to the performance of a two-stage plasma gasification process with RDF. The temperature range of the experiment was from 1400 to 1600 K and for all cases, a medium calorific value syngas was produced with lower heating values up to 10.9 MJ/Nm(3), low levels of tar, high levels of CO and H2 and which composition was in good agreement to the equilibrium composition. The carbon conversion efficiency ranged from 80% to 100% and maximum cold gas efficiency and mechanical gasification efficiency of respectively 56% and 95%, were registered. Overall, the treatment of RDF proved to be less performant than that of biomass in the same system. Compared to a two-stage plasma gasification system, the produced syngas from the single-stage reactor showed more favourable characteristics, while the recovery of the solid residue as a vitrified slag is an advantage of the two-stage set-up. Copyright �

Experimental Study of Thermal Field Evolution in the Short-Impending Stage Before Earthquakes

Science.gov (United States)

Ren, Yaqiong; Ma, Jin; Liu, Peixun; Chen, Shunyun

2017-08-01

Phenomena at critical points are vital for identifying the short-impending stage prior to earthquakes. The peak stress is a critical point when stress is converted from predominantly accumulation to predominantly release. We call the duration between the peak stress and instability "the meta-instability stage", which refers to the short-impending stage of earthquakes. The meta-instability stage consists of a steady releasing quasi-static stage and an accelerated releasing quasi-dynamic stage. The turning point of the above two stages is the remaining critical point. To identify the two critical points in the field, it is necessary to study the characteristic phenomena of various physical fields in the meta-instability stage in the laboratory, and the strain and displacement variations were studied. Considering that stress and relative displacement can be detected by thermal variations and peculiarities in the full-field observations, we employed a cooled thermal infrared imaging system to record thermal variations in the meta-instability stage of stick slip events generated along a simulated, precut planer strike slip fault in a granodiorite block on a horizontally bilateral servo-controlled press machine. The experimental results demonstrate the following: (1) a large area of decreasing temperatures in wall rocks and increasing temperatures in sporadic sections of the fault indicate entrance into the meta-instability stage. (2) The rapid expansion of regions of increasing temperatures on the fault and the enhancement of temperature increase amplitude correspond to the turning point from the quasi-static stage to the quasi-dynamic stage. Our results reveal thermal indicators for the critical points prior to earthquakes that provide clues for identifying the short-impending stage of earthquakes.

Investigation of Advanced Propellants to Enable Single Stage to Orbit Launch Vehicles

Science.gov (United States)

2006-10-30

ERS-PAS-2006-205) 13. SUPPLEMENTARY NOTES Graduate work for California State University, Fresno 14. ABSTRACT Single-Stage-To-Orbit ( SSTO ...and maintained. Despite well-funded development efforts, no SSTO vehicles have been fielded to date. Existing chemical rocket and vehicle...technologies do not enable feasible SSTO designs. In the future, new propellants with advanced properties could enable SSTO launch vehicles. A parametric

Single-stage soft tissue reconstruction and orbital fracture repair for complex facial injuries.

Science.gov (United States)

Wu, Peng Sen; Matoo, Reshvin; Sun, Hong; Song, Li Yuan; Kikkawa, Don O; Lu, Wei

2017-02-01

Orbital fractures with open periorbital wounds cause significant morbidity. Timing of debridement with fracture repair and soft tissue reconstruction is controversial. This study focuses on the efficacy of early single-stage repair in combined bony and soft tissue injuries. Retrospective review. Twenty-three patients with combined open soft tissue wounds and orbital fractures were studied for single-stage orbital reconstruction and periorbital soft tissue repair. Inclusion criteria were open soft tissue wounds with clinical and radiographic evidence of orbital fractures and repair performed within 48 h after injury. Surgical complications and reconstructive outcomes were assessed over 6 months. The main outcome measures were enophthalmos, pre- and post-CT imaging of orbits, scar evaluation, presence of diplopia, and eyelid position. Enophthalmos was corrected in 16/19 cases and improved in 3/19 cases. 3D reconstruction of CT images showed markedly improved orbital alignment with objective measurements of the optic foramen to cornea distance (mm) in reconstructed orbits relative to intact orbits of 0.66, 95% confidence interval [CI] (lower 0.33, upper 0.99) mm. The mean baseline of Stony Brook Scar Evaluation Scale was 0.6, 95%CI (0.30-0.92), and for 6 months, the mean score was 3.4, 95%CI (3.05-3.73). Residual diplopia in secondary gazes was present in two patients; one patient had ectropion. Complications included one case of local wound infection. An early single-stage repair of combined soft tissue and orbital fractures yields satisfactory functional and aesthetic outcomes. Complications are low and likely related to trauma severity. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

The μ-RWELL: A compact, spark protected, single amplification-stage MPGD

Science.gov (United States)

Poli Lener, M.; Bencivenni, G.; de Olivera, R.; Felici, G.; Franchino, S.; Gatta, M.; Maggi, M.; Morello, G.; Sharma, A.

2016-07-01

In this work we present two innovative architectures of resistive MPGDs based on the WELL-amplification concept: - the micro-Resistive WELL (μ-RWELL) is a compact spark-protected single amplification-stage Micro-Pattern Gas Detector (MPGD). The amplification stage, realized with a structure very similar to a GEM foil (called WELL), is embedded through a resistive layer in the readout board. A cathode electrode, defining the gas conversion/drift gap, completes the detector mechanics. The new architecture, showing an excellent space resolution, 50 μm, is a very compact device, robust against discharges and exhibiting a large gain (>104), simple to construct and easy for engineering and then suitable for large area tracking devices as well as digital calorimeters. - the Fast Timing Micro-pattern (FTM): a new device with an architecture based on a stack of several coupled full-resistive layers where drift and multiplication stages (WELL type) alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings, providing a signal with a gain of 104-105. The main advantage of this new device is the improvement of the timing provided by the competition of the ionization processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as for applications like medical imaging.

Theoretical and experimental study of single particle tracking in extreme conditions: single photon imaging

International Nuclear Information System (INIS)

Cajgfinger, T.

2012-10-01

This manuscript presents my thesis on the high frame rate (500 frames / second) single-photon detector electron-bombarded CMOS (ebCMOS). The first section compares three ultra-sensitive detectors and their methods for improving photon sensitivity: the CMOS low noise (sCMOS), the electron-multiplying CCD (emCCD) with signal multiplication by pixel and the ebCMOS with amplification by applied electric field. The method developed to detect single photon impacts with intra-pixel resolution on the ebCMOS sensor is presented. The second section compares the localization accuracy of these detectors in extreme conditions of very low photon flux (<10 photons/frame). First the theoretical limit is calculated using the Cramer-Rao lower bound for significant parameter sets. An experimental comparison of the detectors is then described. The setup provides one or more point sources controlled in position, signal and background noise. The results allow a comparison of the experimental effectiveness, purity and localization accuracy. The last section describes two experiments with the ebCMOS camera. The first aims at tracking hundreds of quantum dots simultaneously at the Nanoptec center. The second focuses on the swimming of bacteria at the surface at the Joliot Curie Institute. The point sources tracking algorithm using single photons and the Kalman filter implementation developed for these experiments is also described. (author)

Comparison of feature and classifier algorithms for online automatic sleep staging based on a single EEG signal

NARCIS (Netherlands)

Radha, M.; Garcia Molina, G.; Poel, M.; Tononi, G.

2014-01-01

Automatic sleep staging on an online basis has recently emerged as a research topic motivated by fundamental sleep research. The aim of this paper is to find optimal signal processing methods and machine learning algorithms to achieve online sleep staging on the basis of a single EEG signal. The

DeepSleepNet: A Model for Automatic Sleep Stage Scoring Based on Raw Single-Channel EEG.

Science.gov (United States)

Supratak, Akara; Dong, Hao; Wu, Chao; Guo, Yike

2017-11-01

This paper proposes a deep learning model, named DeepSleepNet, for automatic sleep stage scoring based on raw single-channel EEG. Most of the existing methods rely on hand-engineered features, which require prior knowledge of sleep analysis. Only a few of them encode the temporal information, such as transition rules, which is important for identifying the next sleep stages, into the extracted features. In the proposed model, we utilize convolutional neural networks to extract time-invariant features, and bidirectional-long short-term memory to learn transition rules among sleep stages automatically from EEG epochs. We implement a two-step training algorithm to train our model efficiently. We evaluated our model using different single-channel EEGs (F4-EOG (left), Fpz-Cz, and Pz-Oz) from two public sleep data sets, that have different properties (e.g., sampling rate) and scoring standards (AASM and R&K). The results showed that our model achieved similar overall accuracy and macro F1-score (MASS: 86.2%-81.7, Sleep-EDF: 82.0%-76.9) compared with the state-of-the-art methods (MASS: 85.9%-80.5, Sleep-EDF: 78.9%-73.7) on both data sets. This demonstrated that, without changing the model architecture and the training algorithm, our model could automatically learn features for sleep stage scoring from different raw single-channel EEGs from different data sets without utilizing any hand-engineered features.

The resistive plate WELL detector as a single stage thick gaseous multiplier detector

Energy Technology Data Exchange (ETDEWEB)

Bressler, Shikma; Breskin, Amos; Moleri, Luca; Kumar, Ashwini; Pitt, Michael [Department of Particle Physics and Astrophysics, Weizmann Institute of Science (WIS) (Israel); Kudella, Simon [Institut fuer Experimentelle Kernphysik (IEKP), KIT (Germany)

2015-07-01

Gaseous Electron Multiplier (GEM) detector use high electric fields inside the h ole of a foil to achieve a high charge multiplication. As a thicker version of G EMs based on printed circuit board (PCB) structures, Thick Gaseous Electron Multiplier (THGEM) detectors combine the high gain of a GEM foil with the robustness, stability and low production costs of a PCB and allow a large quantity of applications that require the coverage of a large area at low cost and moderate spatial resolution. One application the Weizmann Institute of Science (WIS) develops as a member of the RD51 framework is the Resistive Plate WELL (RPWELL) detector. This single stage detector allows a very stable, discharge free operation at high gain (10{sup 5}). The single stage operation allows a low total height and make s the RPWELL a candidate for the Digital Hadronic Calorimeter (DHCAL) of the International Large Detector (ILD) at the International Linear Collider (ILC). The talk gives an insight into the way the RPWELL works and shows results from the last test beam.

Experimental study on the performance of single screw expanders by gap adjustment

International Nuclear Information System (INIS)

Wang, Wei; Wu, Yu-ting; Ma, Chong-fang; Xia, Guo-dong; Wang, Jing-fu

2013-01-01

Improving thermodynamic efficiency of prime movers is the key issue for efficient utilization of low-temperature heat resources. Single screw expander may be a good candidate because of its many good characteristics. Precisions in manufacture and assembly are very important factors to the performance of single screw expanders. In this paper, the shaft efficiency, volumetric efficiency and gas consumption rate of the single screw expander prototypes were tested and discussed. We have manufactured three prototypes with different gaps to investigate their performance. The first prototype (A) has the largest gap, and the second one (B) has the smallest gap, the third prototype (C) has the medium gap configuration. Experimental result of the prototypes was obtained. From the experimental data of prototype A, the power output was about 5 kW, the gas consumption rate was above 105 kg/kWh and the volumetric efficiency was below 20%, the shaft efficiency was only 34%. From experimental data of prototype B, the mass flow rate was significantly decreased. The power output was only 1.4 kW and the volumetric efficiency was slightly lower than prototype A. The gas consumption rate was much more than that of prototype A. From the experimental data of prototype C, the power output was about 4.5 kW, but the mass flow rate was sharply decreased. The gas consumption rate was about 65 kg/kWh, the maximum volumetric efficiency was about 66%, and the shaft efficiency was about 60%. The experimental results indicated that prototype C of single screw expanders had the best overall performance, which may be further improved by optimizing its configuration. - Highlights: • The experiment for three single screw expander prototypes at different gaps was carried out. • Maximum shaft efficiency is about 60%. • Minimum gas consumption rate is about 65 kg/kWh. • Maximum volumetric efficiency is about 66%. • Leaked gas still has part of working capability

Clinical Outcomes and Risks of Single-stage Bilateral Unicompartmental Knee Arthroplasty via Oxford Phase III

Directory of Open Access Journals (Sweden)

Tong Ma

2015-01-01

Full Text Available Background: Osteoarthritis often affects the joint bilaterally, and the single-stage (SS unicompartmental knee arthroplasty (UKA is advantageous in terms of a single anesthesia administration, a short hospital stay, lower medical costs, and enhanced patient convenience. However, the complication risk of SS UKA continues to be debated. The aim of this article was to evaluate the clinical effectiveness, complications, and functional recovery of SS and two-stage (TS UKA. Methods: From January 2008 to December 2013, we compared a series of 36 SS UKA with 45 TS UKA for osteoarthritis. The mean age was 65.4 years (range: 55-75 years. The mean body mass index was 25.2 kg/m 2 (range: 22-29 kg/m 2 . The pre- and post-operative Oxford Knee Scores (OKSs, complications, operative times, tourniquet times, the amount of drainage, and hemoglobin (Hb were evaluated. The Chi-square test, Fisher′s exact test, and paired and grouped t-tests were used in this study. Results: The mean follow-up was 50 months. No complications of death, fat embolism, deep vein thrombosis, and prosthetic infection were reported. Patients who underwent SS UKA had a shorter cumulative anesthesia time (113.5 vs. 133.0 min, P 0.05. At the final follow-up, the mean OKS improved from 39.48 ± 5.69 to 18.83 ± 3.82 (P 0.05. Patients who underwent SS UKA had a faster recovery. Conclusions: The single-staged UKA offers the benefits of a single anesthesia administration, reduced total anesthetic time, decreased overall rehabilitation time, and absence of an increase in perioperative mortality or complications compared with the TS bilateral UKA.

Modeling condom-use stage of change in low-income, single, urban women.

Science.gov (United States)

Morrison-Beedy, Dianne; Carey, Michael P; Lewis, Brian P

2002-04-01

This study was undertaken to identify and test a model of the cognitive antecedents to condom use stage of change in low-income, single, urban women. A convenience sample of 537 women (M=30 years old) attending two urban primary health care settings in western New York State anonymously completed questionnaires based primarily on two leading social-cognitive models, the transtheoretical model and the information-motivation-behavioral skills model. We used structural equation modeling to examine the direct and indirect effects of HIV-related knowledge, social norms of discussing HIV risk and prevention, familiarity with HIV-infected persons, general readiness to change sexual behaviors, perceived vulnerability to HIV, and pros and cons of condom use on condom-use stage of change. The results indicated two models that differ by partner type. Condom-use stage of change in women with steady main partners was influenced most by social norms and the pros of condom use. Condom-use stage of change in women with "other" types (multiple, casual, or new) of sexual partners was influenced by HIV-related knowledge, general readiness to change sexual behaviors, and the pros of condom use. These findings suggest implications for developing gender-relevant HIV-prevention interventions. Copyright 2002 Wiley Periodicals, Inc.

Propulsion requirements for reusable single-stage-to-orbit rocket vehicles

Science.gov (United States)

Stanley, Douglas O.; Engelund, Walter C.; Lepsch, Roger

1994-05-01

The conceptual design of a single-stage-to-orbit (SSTO) vehicle using a wide variety of evolutionary technologies has recently been completed as a part of NASA's Advanced Manned Launch System (AMLS) study. The employment of new propulsion system technologies is critical to the design of a reasonably sized, operationally efficient SSTO vehicle. This paper presents the propulsion system requirements identified for this near-term AMLS SSTO vehicle. Sensitivities of the vehicle to changes in specific impulse and sea-level thrust-to-weight ratio are examined. The results of a variety of vehicle/propulsion system trades performed on the near-term AMLS SSTO vehicle are also presented.

Single Stage Contactor Testing Of The Next Generation Solvent Blend

Energy Technology Data Exchange (ETDEWEB)

Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

2014-01-06

The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

Single-Stage Step up/down Driver for Permanent-Magnet Synchronous Machines

Science.gov (United States)

Chen, T. R.; Juan, Y. L.; Huang, C. Y.; Kuo, C. T.

2017-11-01

The two-stage circuit composed of a step up/down dc converter and a three-phase voltage source inverter is usually adopted as the electric vehicle’s motor driver. The conventional topology is more complicated. Additional power loss resulted from twice power conversion would also cause lower efficiency. A single-stage step up/down Permanent-Magnet Synchronous Motor driver for Brushless DC (BLDC) Motor is proposed in this study. The number components and circuit complexity are reduced. The low frequency six-step square-wave control is used to reduce the switching losses. In the proposed topology, only one active switch is gated with a high frequency PWM signal for adjusting the rotation speed. The rotor position signals are fed back to calculate the motor speed for digital close-loop control in a MCU. A 600W prototype circuit is constructed to drive a BLDC motor with rated speed 3000 rpm, and can control the speed of six sections.

Single Ion transient-IBIC analyses of semiconductor devices using a cryogenic temperature stage

International Nuclear Information System (INIS)

Laird, J.S.; Bardos, R.; Legge, G.J.F.; Jagadish, C.

1998-01-01

A new Transient - IBIC data acquisition and analysis system at MARC is described. A discussion on the need for single ion control and temperature control is also given. The recorded signal is used as the trigger for beam pulsing. The new cryostatic temperature control stage is introduced. Data is presented on line profiles across the edge of a Au-Si junction collected over the temperature range of 25-300K using a developed C-V and I-V variable temperature stage incorporating a liquid helium cryostat. It demonstrates the potential improvements in spatial resolution in materials of long lifetime by mapping on timing windows around the prompt charge component in the charge transient

Effects of Stator Shroud Injection on the Aerodynamic Performance of a Single-Stage Transonic Axial Compressor

Energy Technology Data Exchange (ETDEWEB)

Dinh, Cong-Truong; Ma, Sang-Bum; Kim, Kwang Yong [Inha Univ., Incheon (Korea, Republic of)

2017-01-15

In this study, stator shroud injection in a single-stage transonic axial compressor is proposed. A parametric study of the effect of stator shroud injection on aerodynamic performances was conducted using the three-dimensional Reynolds-averaged Navier-Stokes equations. The curvature, length, width, and circumferential angle of the stator shroud injector and the air injection mass flow rate were selected as the test parameters. The results of the parametric study show that the aerodynamic performances of the single-stage transonic axial compressor were improved by stator shroud injection. The aerodynamic performances were the most sensitive to the injection mass flow rate. Further, the total pressure ratio and adiabatic efficiency were the maximum when the ratio of circumferential angle was 10%.

Effects of Stator Shroud Injection on the Aerodynamic Performance of a Single-Stage Transonic Axial Compressor

International Nuclear Information System (INIS)

Dinh, Cong-Truong; Ma, Sang-Bum; Kim, Kwang Yong

2017-01-01

In this study, stator shroud injection in a single-stage transonic axial compressor is proposed. A parametric study of the effect of stator shroud injection on aerodynamic performances was conducted using the three-dimensional Reynolds-averaged Navier-Stokes equations. The curvature, length, width, and circumferential angle of the stator shroud injector and the air injection mass flow rate were selected as the test parameters. The results of the parametric study show that the aerodynamic performances of the single-stage transonic axial compressor were improved by stator shroud injection. The aerodynamic performances were the most sensitive to the injection mass flow rate. Further, the total pressure ratio and adiabatic efficiency were the maximum when the ratio of circumferential angle was 10%.

Single-stage-to-orbit: Meeting the challenge

Science.gov (United States)

Freeman, Delma C., Jr.; Talay, Theodore A.; Austin, Robert Eugene

1995-10-01

There has been and continues to be significant discussion about the viability of fully reusable, single-stage-to-orbit (SSTO) concepts for delivery of payloads to orbit. Often, these discussions have focused in detail on performance and technology requirements relating to the technical feasibility of the concept, with only broad generalizations on how the SSTO will achieve its economic goals of greatly reduced vehicle ground and flight operations costs. With the current industry and NASA Reusable Launch Vehicle Technology Program efforts underway to mature and demonstrate technologies leading to a viable commercial launch system that also satisfies national needs, achieving acceptable recurring costs becomes a significant challenge. This paper reviews the current status of the Reusable Launch Vehicle Technology Program including the DC-XA, X-33, and X-34 flight systems and associated technology programs. The paper also examines lessons learned from the recently completed DC-X reusable rocket demonstrator program. It examines how these technologies and flight systems address the technical and operability challenges of SSTO whose solutions are necessary to reduce costs. The paper also discusses the management and operational approaches that address the challenge of a new cost-effective, reusable launch vehicle system.

Experimental analysis of humidification process by air passing through seawater

International Nuclear Information System (INIS)

El-Agouz, S.A.; Abugderah, M.

2008-01-01

An experimental investigation of humidification process by air passing through seawater is presented. The main objective of this work was to determine the humid air behaviour through single-stage of heating-humidifying processes. This experimental work studied the influence of the operating conditions such as the water temperature, the headwater difference, the air velocity and the inlet air temperature to evaporator chamber on the vapour content difference and humidification efficiency. Two cases of different inlet conditions of ambient and heated air cases are studied. The experimental results show that, the vapour content difference and the humidification efficiency of the system is strongly affected by the saline water temperature in the evaporator chamber, headwater difference and the air velocity. The inlet air temperature to evaporator chamber variation was found to have a small affect on the vapour content difference. The obtained maximum vapour content difference of the air was about 222 gr w /kg a at 75 deg. C for water and air. The obtained vapour content is high compared to that obtained in literature for single-stage and very similar for multi-stage

Publishing Single-Case Research Design Studies That Do Not Demonstrate Experimental Control

Science.gov (United States)

Tincani, Matt; Travers, Jason

2018-01-01

Demonstration of experimental control is considered a hallmark of high-quality single-case research design (SCRD). Studies that fail to demonstrate experimental control may not be published because researchers are unwilling to submit these papers for publication and journals are unlikely to publish negative results (i.e., the file drawer effect).…

Advances in single- and multi-stage Stirling-type pulse tube cryocoolers for space applications in NLIP/SITP/CAS

Science.gov (United States)

Dang, Haizheng; Tan, Jun; Zha, Rui; Li, Jiaqi; Zhang, Lei; Zhao, Yibo; Gao, Zhiqian; Bao, Dingli; Li, Ning; Zhang, Tao; Zhao, Yongjiang; Zhao, Bangjian

2017-12-01

This paper presents a review of recent advances in single- and multi-stage Stirling-type pulse tube cryocoolers (SPTCs) for space applications developed at the National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences (NLIP/SITP/CAS). A variety of single-stage SPTCs operating at 25-150 K have been developed, including several mid-sized ones operating at 80-110 K. Significant progress has been achieved in coolers operating at 30-40 K which use common stainless steel meshes as regenerator matrices. Another important advance is the micro SPTCs with an overall mass of 300-800 g operating at high frequencies varying from 100 Hz to 400 Hz. The main purpose of developing two-stage SPTCs is to simultaneously acquire cooling capacities at both stages, obviating the need for auxiliary precooling in various applications. The three-stage SPTCs are developed mainly for applications at around 10 K, which are also used for precooling the J-T coolers to achieve further lower temperatures. The four-stage SPTCs are developed to directly achieve the liquid helium temperature for cooling space low-Tc superconducting devices and for the deep space exploration as well. Several typical development programs are described and an overview of the cooler performances is presented.

Experimental study of single event burnout and single event gate rupture in power MOSFETs and IGBT

International Nuclear Information System (INIS)

Tang Benqi; Wang Yanping; Geng Bin

2001-01-01

An experimental study was carried out to determine the single event burnout and single event gate rupture sensitivities in power MOSFETs and IGBT which were exposed to heavy ions from 252 Cf source. The test method, test results, a description of observed burnout current waveforms and a discussion of a possible failure mechanism were presented. Current measurements have been performed with a specially designed circuit. The test results include the observed dependence upon applied drain or gate to source bias and versus with external capacitors and limited resistors

Computational/experimental studies of isolated, single component droplet combustion

Science.gov (United States)

Dryer, Frederick L.

1993-01-01

Isolated droplet combustion processes have been the subject of extensive experimental and theoretical investigations for nearly 40 years. The gross features of droplet burning are qualitatively embodied by simple theories and are relatively well understood. However, there remain significant aspects of droplet burning, particularly its dynamics, for which additional basic knowledge is needed for thorough interpretations and quantitative explanations of transient phenomena. Spherically-symmetric droplet combustion, which can only be approximated under conditions of both low Reynolds and Grashof numbers, represents the simplest geometrical configuration in which to study the coupled chemical/transport processes inherent within non-premixed flames. The research summarized here, concerns recent results on isolated, single component, droplet combustion under microgravity conditions, a program pursued jointly with F.A. Williams of the University of California, San Diego. The overall program involves developing and applying experimental methods to study the burning of isolated, single component droplets, in various atmospheres, primarily at atmospheric pressure and below, in both drop towers and aboard space-based platforms such as the Space Shuttle or Space Station. Both computational methods and asymptotic methods, the latter pursued mainly at UCSD, are used in developing the experimental test matrix, in analyzing results, and for extending theoretical understanding. Methanol, and the normal alkanes, n-heptane, and n-decane, have been selected as test fuels to study time-dependent droplet burning phenomena. The following sections summarizes the Princeton efforts on this program, describe work in progress, and briefly delineate future research directions.

NASA Glenn's Single-Stage Axial Compressor Facility Upgraded

Science.gov (United States)

Brokopp, Richard A.

2004-01-01

NASA Glenn Research Center's Single-Stage Axial Compressor Facility was upgraded in fiscal year 2003 to expand and improve its research capabilities for testing high-speed fans and compressors. The old 3000-hp drive motor and gearbox were removed and replaced with a refurbished 7000-hp drive motor and gearbox, with a maximum output speed of 21,240 rpm. The higher horsepower rating permits testing of fans and compressors with higher pressure ratio or higher flow. A new inline torquemeter was installed to provide an alternate measurement of fan and compressor efficiency, along with the standard pressure and temperature measurements. A refurbished compressor bearing housing was also installed with bidirectional rotation capability, so that a variety of existing hardware could be tested. Four new lubrication modules with backup capability were installed for the motor, gearbox, torquemeter, and compressor bearing housing, so that in case the primary pump fails, the backup will prevent damage to the rotating hardware. The combustion air supply line for the facility inlet air system was activated to provide dry air for repeatable inlet conditions. New flow conditioning hardware was installed in the facility inlet plenum tank, which greatly reduced the inlet turbulence. The new inlet can also be easily modified to accommodate 20- or 22-in.-diameter fans and compressors, so a variety of existing hardware from other facilities (such as Glenn's 9- by 15-Foot Low-Speed Wind Tunnel) can be tested in the Single-Stage Axial Compressor Facility. An exhaust line was also installed to provide bleed capability to remove the inlet boundary layer. To improve the operation and control of the facility, a new programmable logic controller (PLC) was installed to upgrade from hardwired relay logic to software logic. The PLC also enabled the usage of human-machine interface software to allow for easier operation of the facility and easier reconfiguration of the facility controls when

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

Directory of Open Access Journals (Sweden)

Liogienė Tatjana

2016-07-01

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

Effect of Single and Double Stage Chemically Treated Kenaf Fibers on Mechanical Properties of Polyvinyl Alcohol Film

Directory of Open Access Journals (Sweden)

Md Ershad Ali

2014-12-01

Full Text Available The physico-mechanical properties of lignocellulosic kenaf fiber reinforced polyvinyl alcohol (PVA biocomposite films were investigated. To improve the properties of the biocomposite, kenaf fibers were chemically treated separately in a single stage (with Cr2(SO4312(H2O and double stages (with CrSO4 and NaHCO3 to improve the adhesion and compatibility between the kenaf fiber and PVA matrix. PVA was reinforced with various compositions of chemically treated kenaf fiber by using a solution casting technique. Microstructural analyses and mechanical tests were subsequently conducted. Scanning electron microscopic analysis indicated that chemical treatment improved the uniformity distribution of kenaf fiber within the PVA matrix. FTIR and XRD analyses confirmed the presence of chromium on the fiber surface. The tensile strength of PVA reinforced with chemical treated kenaf fiber was found to be higher than those reinforced with untreated kenaf. The Young’s modulus, flexural strength, and flexural modulus increased with fiber loading for both untreated and treated kenaf fiber reinforced PVA films. The double stage treated kenaf fiber showed better mechanical properties and lower moisture uptake than the single stage treated kenaf fiber.

Single-stage three-phase AC to DC conversion with isolation and Bi-directional power flow

NARCIS (Netherlands)

Vermulst, B.J.D.; Duarte, J.L.; Wijnands, C.G.E.; Lomonova, E.A.

2014-01-01

An approach for three-phase AC to DC conversion is proposed, which consists of a single-stage while offering galvanic isolation, soft-switching, bi-directional power flow and a significant reduction of inductive and capacitive energy storage. Two elements enable this approach, namely a neutral

Simulation model of a single-stage lithium bromide-water absorption cooling unit

Science.gov (United States)

Miao, D.

1978-01-01

A computer model of a LiBr-H2O single-stage absorption machine was developed. The model, utilizing a given set of design data such as water-flow rates and inlet or outlet temperatures of these flow rates but without knowing the interior characteristics of the machine (heat transfer rates and surface areas), can be used to predict or simulate off-design performance. Results from 130 off-design cases for a given commercial machine agree with the published data within 2 percent.

Experimental investigation of submerged single jet impingement using Cu–water nanofluid

International Nuclear Information System (INIS)

Li Qiang; Xuan Yimin; Yu Feng

2012-01-01

Jet impingement cooling is a vital technique for thermal management of electronic devices of high-heat-flux by impinging fluid on a heater surface due to its high local heat transfer rates. In this paper, two types of Cu–water nanofluids (Cu particles with 25 nm diameter or 100 nm) are introduced into submerged single jet impingement cooling system as the working fluid. The heat transfer features of the nanofluids were experimentally investigated. The effects of the nanoparticle concentration, Reynolds number, nozzle-to-plate distance, fluid temperature, and nanoparticle diameter on the heat transfer performances of the jet impingement of nanofluids are discussed. The experimental results show that the suspended nanoparticles remarkably increase the convective heat transfer coefficient of the base fluid. The convective heat transfer coefficient of Cu–water nanofluid with the volume fraction of 3.0% has 52% higher than the pure water. The experiments also revealed that the suspended nanoparticles brought almost no extra addition of pressure drop in both submerged single jet impingement. In addition, by considering the effects of the suspended nanoparticles as well as the condition of impinging jet, a new heat transfer correlation of nanofluids for the submerged single jet impingement has been proposed. - Highlights: ► Cu–water nanofluids are introduced into submerged single jet impingement. ► The affecting parameters on the heat transfer performances of nanofluids are discussed. ► New heat transfer correlation of nanofluid for single jet impingement is proposed.

Single-stage MPPT control realization for Aalborg inverter in photovoltaic system

DEFF Research Database (Denmark)

Zhang, Shuai; Wu, Weimin; Wang, Houqing

2017-01-01

In this paper, the single-stage Maximum Power Point Tracking (MPPT) control strategy for the Aalborg photovoltaic inverter is presented. Aalborg inverter has many advantages, such as high efficiency, wide range of input voltage, minimum voltage drop of the filtering inductors, etc. Nevertheless......, it is essentially a “half-bridge” inverter with two input sources, where one source works in MPPT mode, the other is out of control. If without the reasonable parameter design and the proper control, the bus-voltage of this inverter may change greatly, resulting in the serious power oscillation around maximum power...

Stage 2: dismantling of reactor case of the experimental F.B.R. Rapsodie

International Nuclear Information System (INIS)

Roger, J.

1994-01-01

This document defines the main objectives of stage 2 dismantling of the Rapsodie experimental fast neutron reactor and specifies its time schedule. The work already in progress consists in containing the reactor vessel and its internal equipment, as well as the neutron protection concrete, inside the two leak-tight barriers, and in dismantling all the systems and equipment systems contaminated by sodium. This work, which includes the destruction of 37 metric tons of contaminated sodium from the primary system, was begun in 1987 and will be completed in 1994. The duration of the waiting period for complete dismantling (stage 3) has not been defined. However, the containment and monitoring means implemented should allow a safe waiting period of several decades. (author). 4 figs

The techniques of quality operations computational and experimental researches of the launch vehicles in the drawing-board stage

Science.gov (United States)

Rozhaeva, K.

2018-01-01

The aim of the researchis the quality operations of the design process at the stage of research works on the development of active on-Board system of the launch vehicles spent stages descent with liquid propellant rocket engines by simulating the gasification process of undeveloped residues of fuel in the tanks. The design techniques of the gasification process of liquid rocket propellant components residues in the tank to the expense of finding and fixing errors in the algorithm calculation to increase the accuracy of calculation results is proposed. Experimental modelling of the model liquid evaporation in a limited reservoir of the experimental stand, allowing due to the false measurements rejection based on given criteria and detected faults to enhance the results reliability of the experimental studies; to reduce the experiments cost.

Direct experimental observation of nonclassicality in ensembles of single-photon emitters

Science.gov (United States)

Moreva, E.; Traina, P.; Forneris, J.; Degiovanni, I. P.; Ditalia Tchernij, S.; Picollo, F.; Brida, G.; Olivero, P.; Genovese, M.

2017-11-01

In this work we experimentally demonstrate a recently proposed criterion addressed to detect nonclassical behavior in the fluorescence emission of ensembles of single-photon emitters. In particular, we apply the method to study clusters of nitrogen-vacancy centers in diamond characterized with single-photon-sensitive confocal microscopy. Theoretical considerations on the behavior of the parameter at any arbitrary order in the presence of Poissonian noise are presented and, finally, the opportunity of detecting manifold coincidences is discussed.

Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop

International Nuclear Information System (INIS)

Ribando, R.J.

1979-01-01

A comparison is made between computed results and experimental data for single-phase natural convection in an experimental sodium loop. The tests were conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) Facility, an engineering-scale high temperature sodium facility at the Oak Ridge National Laboratory used for thermal-hydraulic testing of simulated LMFBR subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during these tests was typical of decay heat levels. Tests were conducted both with zero initial forced flow and with a small initial forced flow. The bypass line was closed in most tests, but open in one. The computer code used to analyze these tests [LONAC (LOw flow and NAtural Convection)] is an ORNL-developed, fast running, one-dimensional, single-phase finite difference model for simulating forced and free convection transients in the THORS loop

Tranexamic acid for control of blood loss in bilateral total knee replacement in a single stage

Directory of Open Access Journals (Sweden)

Mandeep S Dhillon

2011-01-01

Full Text Available Background: Tranexamic acid (TEA reduces blood loss and red cell transfusions in patients undergoing unilateral total knee arthroplasty (TKA. However, there is not much literature regarding the use of TEA in patients undergoing bilateral TKA in a single stage and the protocols for administration of TEA in such patients are ill-defined. Materials and Methods: We carried out a case control study evaluating the effect of TEA on postoperative hemoglobin (Hb, total drain output, and number of blood units transfused in 52 patients undergoing bilateral TKA in a single stage, and compared it with 56 matched controls who did not receive TEA. Two doses of TEA were administered in doses of 10 mg / kg each (slow intravenous (IV infusion, with the first dose given just before tourniquet release of the first knee and the second dose three hours after the first one. Results: A statistically significant reduction in the total drain output and requirement of allogenic blood transfusion in cases who received TEA, as compared to the controls was observed. The postoperative Hb and Hb at the time of discharge were found to be lower in the control group, and this result was found to be statistically significant. Conclusion: TEA administered in patients undergoing single stage bilateral TKA helped reduce total blood loss and decreased allogenic blood transfusion requirements. This might be particularly relevant, where facilities such as autologous reinfusion might not be available.

Feasibility study of generating ultra-high harmonic radiation with a single stage echo-enabled harmonic generation scheme

Energy Technology Data Exchange (ETDEWEB)

Zhou, Kaishang, E-mail: zhoukaishang@sinap.ac.cn; Feng, Chao, E-mail: fengchao@sinap.ac.cn; Wang, Dong, E-mail: wangdong@sinap.ac.cn

2016-10-21

The echo enabled harmonic generation (EEHG) scheme holds the ability for the generation of fully coherent soft x-ray free-electron laser (FEL) pulses directly from external UV seeding sources. In this paper, we study the feasibility of using a single stage EEHG to generate coherent radiation in the “water window” and beyond. Using the high-order operating modes of the EEHG scheme, intensive numerical simulations have been performed considering various three-dimensional effects. The simulation results demonstrated that coherent soft x-ray radiation at 150th harmonic (1.77 nm) of the seed can be produced by a single stage EEHG. The decreasing of the final bunching factor at the desired harmonic caused by intra beam scattering (IBS) effect has also been analyzed.

Analysis of U and Pu resin bead samples with a single stage mass spectrometer

International Nuclear Information System (INIS)

Smith, D.H.; Walker, R.L.; Bertram, L.K.; Carter, J.A.

1979-01-01

Resin bead sampling enables the shipment of nanogram U and Pu quantities for analysis. Application of this sampling technique to safeguards was investigated with a single-stage mass spectrometer. Standards gave results in good agreement with NBS certified values. External precisions of +-0.5% were obtained on isotopic ratios of approx. 0.01; precisions on quantitative measurements are +-1.0%

MR diffusion weighted imaging experimental study on early stages of articular cartilage degeneration of knee

International Nuclear Information System (INIS)

Dai Jingru; Dai Shipeng; Pang Jun; Xu Xiaokun; Wang Yuexin; Zhang Zhigang

2008-01-01

Objective: To study the appearance of MR diffusion weighted imaging in early stages of cartilage degeneration and to detect its values. Methods: In 20 goat left knees, intra- articular injection of 5 units of papain was performed causing a loss of cartilage proteoglycan. Twenty right knees were used as control group. MR diffusion weighted imaging was performed at 24 hours after intra-articular injection of papain. ADC of each part of articular cartilage was measured and compared with each other. The proteoglycan content was measured biochemically and histochemically. Routine MRI and DWI were performed in 100 patients with osteoarthritis and 20 healthy people. The ADC of each interested part of articular cartilage was measured and compared with each other. Results: In experimental control group, the ADCav of articular cartilage was (14.2±2.3) x 10 -4 mm 2 /s. In early stages of cartilage degeneration group, the ADCav of articular cartilage was (17.5±4.2) x 10 -4 mm 2 /s. The ADCav of the control group was lower than that of the early stages of cartilage degeneration group (t=2.709; P=0.016). The proteloglycan content of articular cartilage was 4.22 x 10 6 μg/kg in control group, and 0.82 x 10 6 μg/kg in experimental group at 24 hours after injection of papain. The difference between control group and experimental group was significant (t=2.705, P=0.018). In healthy people, the ADCav of articular cartilage was (7.6±2.2) x 10 -4 mm 2 /s. In osteoarthritis group, the ADCav of articular cartilage was (10.3±4.2) x 10 -4 mm 2 /s. The ADCav in the healthy group was significantly lower than that in the osteoarthritis group (t=2.609,P=0.014). Conclusion: DWI is an useful method in detecting early stages of cartilage degeneration which can not be showed on routine sequences. (authors)

Single-stage revision for fungal peri-prosthetic joint infection: a single-centre experience.

Science.gov (United States)

Klatte, T O; Kendoff, D; Kamath, A F; Jonen, V; Rueger, J M; Frommelt, L; Gebauer, M; Gehrke, T

2014-04-01

Fungal peri-prosthetic infections of the knee and hip are rare but likely to result in devastating complications. In this study we evaluated the results of their management using a single-stage exchange technique. Between 2001 and 2011, 14 patients (ten hips, four knees) were treated for a peri-prosthetic fungal infection. One patient was excluded because revision surgery was not possible owing to a large acetabular defect. One patient developed a further infection two months post-operatively and was excluded from the analysis. Two patients died of unrelated causes. After a mean of seven years (3 to 11) a total of ten patients were available for follow-up. One patient, undergoing revision replacement of the hip, had a post-operative dislocation. Another patient, undergoing revision replacement of the knee, developed a wound infection and required revision 29 months post-operatively following a peri-prosthetic femoral fracture. The mean Harris hip score increased to 74 points (63 to 84; p prosthetic infection is feasible, with an acceptable rate of a satisfactory outcome.

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

KAUST Repository

Lee, Jung Gil

2016-10-24

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

Fault Diagnosis for Engine Based on Single-Stage Extreme Learning Machine

Directory of Open Access Journals (Sweden)

Fei Gao

2016-01-01

Full Text Available Single-Stage Extreme Learning Machine (SS-ELM is presented to dispose of the mechanical fault diagnosis in this paper. Based on it, the traditional mapping type of extreme learning machine (ELM has been changed and the eigenvectors extracted from signal processing methods are directly regarded as outputs of the network’s hidden layer. Then the uncertainty that training data transformed from the input space to the ELM feature space with the ELM mapping and problem of the selection of the hidden nodes are avoided effectively. The experiment results of diesel engine fault diagnosis show good performance of the SS-ELM algorithm.

Single-staged vs. two-staged implant placement using bone ring technique in vertically deficient alveolar ridges - Part 1: histomorphometric and micro-CT analysis.

Science.gov (United States)

Nakahara, Ken; Haga-Tsujimura, Maiko; Sawada, Kosaku; Kobayashi, Eizaburo; Mottini, Matthias; Schaller, Benoit; Saulacic, Nikola

2016-11-01

Simultaneous implant placement with bone grafting shortens the overall treatment period, but might lead to the peri-implant bone loss or even implant failure. The aim of this study was to compare the single-staged to two-staged implant placement using the bone ring technique. Four standardized alveolar bone defects were made in the mandibles of nine dogs. Dental implants (Straumann BL ® , Basel, Switzerland) were inserted simultaneously with bone ring technique in test group and after 6 months of healing period in control group. Animals of both groups were euthanized at 3 and 6 months of osseointegration period. The harvested samples were analyzed by means of histology and micro-CT. The amount of residual bone decreased while the amount of new bone increased up to 9 months of healing period. All morphometric parameters remained stable between 3 and 6 months of osseointegration period within groups. Per a given time point, median area of residual bone graft was higher in test group and area of new bone in control group. The volume of bone ring was greater in test than in control group, reaching the significance at 6 months of osseointegration period (P = 0.002). In the present type of bone defect, single-staged implant placement may be potentially useful to shorten an overall treatment period. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Strain preservation of experimental animals: vitrification of two-cell stage embryos for multiple mouse strains.

Science.gov (United States)

Eto, Tomoo; Takahashi, Riichi; Kamisako, Tsutomu

2015-04-01

Strain preservation of experimental animals is crucial for experimental reproducibility. Maintaining complete animal strains, however, is costly and there is a risk for genetic mutations as well as complete loss due to disasters or illness. Therefore, the development of effective vitrification techniques for cryopreservation of multiple experimental animal strains is important. We examined whether a vitrification method using cryoprotectant solutions, P10 and PEPeS, is suitable for preservation of multiple inbred and outbred mouse strains. First, we investigated whether our vitrification method using cryoprotectant solutions was suitable for two-cell stage mouse embryos. In vitro development of embryos exposed to the cryoprotectant solutions was similar to that of fresh controls. Further, the survival rate of the vitrified embryos was extremely high (98.1%). Next, we collected and vitrified two-cell stage embryos of 14 mouse strains. The average number of embryos obtained from one female was 7.3-33.3. The survival rate of vitrified embryos ranged from 92.8% to 99.1%, with no significant differences among mouse strains. In vivo development did not differ significantly between fresh controls and vitrified embryos of each strain. For strain preservation using cryopreserved embryos, two offspring for inbred lines and one offspring for outbred lines must be produced from two-cell stage embryos collected from one female. The expected number of surviving fetuses obtained from embryos collected from one female of either the inbred or outbred strains ranged from 2.9 to 19.5. The findings of the present study indicated that this vitrification method is suitable for strain preservation of multiple mouse strains. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Advanteges of using Two-Switch Forward in Single-Stage Power Factor Corrected Power Supplies

DEFF Research Database (Denmark)

Petersen, Lars

2000-01-01

A single-Stage power factor corrected power supply using a two-switch forward is proposed to increase efficiency. The converter is operated in the DCM (Discontinues Conduction Mode). This will insure the intermediate DC-bus to be controlled only by means of circuit parameters and therefore...... power supply has been implemented. The measured efficiency and power factor are about 87% and 0.96 respectively....

Single stage buck-boost DC-AC neutral point clamped inverter

DEFF Research Database (Denmark)

Mo, Wei; Loh, Poh Chiang; Andrew, A.

2012-01-01

This paper proposes a new single stage buck-boost DC-AC neutral point clamped inverter topology which integrates the cascaded configurations of recently introduced inductor-capacitor-capacitor-transformer impedance source network (by Adamowicz) and classic NPC configuration. As a consequence......, it has enhanced buck-boost functionality and low output voltage distortions compared to the traditional Z-source inverter; it has continuous input current which reduces the source stress and inverter noise; it also contains two built-in capacitors which can block the DC current in the transformer...... windings thus preventing the core from saturation; lowers the voltage stresses and power losses of inverter switches and reduces the sizes of filtering devices and as well as obtains better output performance compared to the original two-level Z-source inverters. A phase disposition pulse width modulation...

Performance and genome-centric metagenomics of thermophilic single and two-stage anaerobic digesters treating cheese wastes

DEFF Research Database (Denmark)

Fontana, Alessandra; Campanaro, Stefano; Treu, Laura

2018-01-01

-depth characterization of the microbial community structure using genome-centric metagenomics. Both reactor configurations showed acidification problems under the tested organic loading rates (OLRs) of 3.6 and 2.4 g COD/L-reactor day and the hydraulic retention time (HRT) of 15 days. However, the two-stage design...... of the main population genomes highlighted specific metabolic pathways responsible for the AD process and the mechanisms of main intermediates production. Particularly, the acetate accumulation experienced by the single stage configuration was mainly correlated to the low abundant syntrophic acetate oxidizer...

New results for single stage low energy carbon AMS

International Nuclear Information System (INIS)

Klody, G.M.; Schroeder, J.B.; Norton, G.A.; Loger, R.L.; Kitchen, R.L.; Sundquist, M.L.

2005-01-01

A new configuration of the NEC single stage, low energy carbon AMS system (U.S. Patent 6,815,666 B2) has been built and tested. The injector includes two 40-sample ion sources, electrostatic and magnetic analysis, and fast sequential injection. The gas stripper, analyzing magnet, electrostatic analyzer, and detector are on an open air 250 kV deck. Both 12 C and 13 C currents are measured on the deck after the stripper, and an SSB detector is used for 14 C counting. Injected 12 C and mass 13 ( 13 C and 12 CH) currents are also measured. Automated controls follow a user-specified run list for unattended operation. Initial test results show precision for 14 C/ 12 C ratios of better than 5 per mil, and backgrounds for unprocessed graphite of less than 0.005 x modern. We will report final results for precision, background, and throughput and discuss related design features

Possible two-stage 87Sr evolution in the Stockdale Rhyolite

International Nuclear Information System (INIS)

Compston, W.; McDougall, I.; Wyborn, D.

1982-01-01

The Rb-Sr total-rock data for the Stockdale Rhyolite, of significance for the Palaeozoic time scale, are more scattered about a single-stage isochron than expected from experimental error. Two-stage 87 Sr evolution for several of the samples is explored to explain this, as an alternative to variation in the initial 87 Sr/ 86 Sr which is customarily used in single-stage dating models. The deletion of certain samples having very high Rb/Sr removes most of the excess scatter and leads to an estimate of 430 +- 7 m.y. for the age of extrusion. There is a younger alignment of Rb-Sr data within each sampling site at 412 +- 7 m.y. We suggest that the Stockdale Rhyolite is at least 430 m.y. old, that its original range in Rb/Sr was smaller than now observed, and that it experienced a net loss in Sr during later hydrothermal alteration at ca. 412 m.y. (orig.)

Experimental Validation of a Permeability Model for Enrichment Membranes

International Nuclear Information System (INIS)

Orellano, Pablo; Brasnarof, Daniel; Florido Pablo

2003-01-01

An experimental loop with a real scale diffuser, in a single enrichment-stage configuration, was operated with air at different process conditions, in order to characterize the membrane permeability.Using these experimental data, an analytical geometric-and-morphologic-based model was validated.It is conclude that a new set of independent measurements, i.e. enrichment, is necessary in order to fully characterize diffusers, because of its internal parameters are not univocally determinated with permeability experimental data only

Experimental single-chip color HDTV image acquisition system with 8M-pixel CMOS image sensor

Science.gov (United States)

Shimamoto, Hiroshi; Yamashita, Takayuki; Funatsu, Ryohei; Mitani, Kohji; Nojiri, Yuji

2006-02-01

We have developed an experimental single-chip color HDTV image acquisition system using 8M-pixel CMOS image sensor. The sensor has 3840 × 2160 effective pixels and is progressively scanned at 60 frames per second. We describe the color filter array and interpolation method to improve image quality with a high-pixel-count single-chip sensor. We also describe an experimental image acquisition system we used to measured spatial frequency characteristics in the horizontal direction. The results indicate good prospects for achieving a high quality single chip HDTV camera that reduces pseudo signals and maintains high spatial frequency characteristics within the frequency band for HDTV.

Single-stage-to-orbit — Meeting the challenge

Science.gov (United States)

Freeman, Delma C.; Talay, Theodore A.; Austin, Robert Eugene

1996-02-01

There has been and continues to be significant discussion about the viability of fully reusable, single-stage-to-orbit (SSTO) concepts for delivery of payloads to orbit. Often, these discussions have focused in detail on performance and technology requirements relating to the technical feasibility of the concept, with only broad generalizations on how the SSTO will achieve its economic goals of greatly reduced vehicle ground and flight operations costs. With the current industry and NASA Reusable Launch Vehicle Technology Program efforts underway to mature and demonstrate technologies leading to a viable commercial launch system that also satisfies national needs, achieving acceptable recurring costs becomes a significant challenge. This paper reviews the current status of the Reusable Launch Vehicle Technology Program including the DC-XA, X-33, X-34 flight systems and associated technology programs. The paper also examines lessons learned from the recently completed DC-X reusable rocket demonstrator program. It examines how these technologies and flight systems address the technical and operability challenges of SSTO whose solutions are necessary to reduce costs. The paper also discusses the management and operational approaches that address the challenge of a new cost-effective, reusable launch vehicle system.

CMOS single-stage input-powered bridge rectifier with boost switch and duty cycle control

Science.gov (United States)

Radzuan, Roskhatijah; Mohd Salleh, Mohd Khairul; Hamzah, Mustafar Kamal; Ab Wahab, Norfishah

2017-06-01

This paper presents a single-stage input-powered bridge rectifier with boost switch for wireless-powered devices such as biomedical implants and wireless sensor nodes. Realised using CMOS process technology, it employs a duty cycle switch control to achieve high output voltage using boost technique, leading to a high output power conversion. It has only six external connections with the boost inductance. The input frequency of the bridge rectifier is set at 50 Hz, while the switching frequency is 100 kHz. The proposed circuit is fabricated on a single 0.18-micron CMOS die with a space area of 0.024 mm2. The simulated and measured results show good agreement.

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

Science.gov (United States)

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

2016-12-15

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

Neurologic Injury and Cerebral Blood Flow In Single Ventricles Throughout Staged Surgical Reconstruction

Science.gov (United States)

Fogel, Mark A.; Li, Christine; Elci, Okan U.; Pawlowski, Tom; Schwab, Peter J.; Wilson, Felice; Nicolson, Susan C.; Montenegro, Lisa M.; Diaz, Laura; Spray, Thomas L.; Gaynor, J William; Fuller, Stephanie; Mascio, Christopher; Keller, Marc S.; Harris, Matthew A.; Whitehead, Kevin K.; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J.

2017-01-01

Background Single ventricle patients experience a high rate of brain injury and adverse neurodevelopmental outcome, however, the incidence of brain abnormalities throughout surgical reconstruction and its relationship with cerebral blood flow, oxygen delivery and carbon dioxide reactivity remains unknown. Methods Single ventricle patients were studied with MRI scans immediately prior to bidirectional Glenn (pre-BDG), prior to Fontan and then 3–9 months after Fontan reconstruction. Results One hundred and sixty eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age 4.8+1.7 months), 118 BDG (2.9+1.4 years) and 54 after Fontan (2.4+1.0 years). Non-acute ischemic white matter changes on T2 weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontans compared to pre-BDG (P<0.05). BDG patients has significantly higher CBF than Fontan patients. The odds of discovering brain injury adjusting for surgical stage as well as 2 or more co-existing lesions within a patient all decreased (63–75% and 44% respectively) with increasing amount of cerebral blood flow (P<0.05). In general, there was no association of oxygen delivery (with the exception of ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury. Conclusion Significant brain abnormalities are commonly present in single ventricle patients and detection of these lesions increase as children progress through staged surgical reconstruction with multiple co-existing lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater CBF than Fontan patients and that there exists an inverse association of various indices of CBF with these brain lesions, however, CO2 reactivity, oxygen delivery (with one exception) were not associated with brain lesion development. PMID:28031423

Control of a Two-Stage Direct Power Converter with a Single Voltage Sensor Mounted in the Intermediary Circuit

DEFF Research Database (Denmark)

Klumpner, Christian; Wheeler, P.; Blaabjerg, Frede

2004-01-01

Controlling a converter requires not only a powerful processors but also accurate voltage and current sensors and fast and precise analogue-digital converters, which increase the cost per kW of the assembly, especially in the low power range. A matrix converter requires less transducers than a back...... converters but in two stages (AC/DC/AC) without using energy storage in the intermediary circuit. They also offer the possibility to reduce the number of switches compared to the standard single-stage matrix converter. This paper presents a new method to control a two-stage DPC providing sine-wave in sine...

Single-stage laparoscopic common bile duct exploration and cholecystectomy versus two-stage endoscopic stone extraction followed by laparoscopic cholecystectomy for patients with concomitant gallbladder stones and common bile duct stones: a randomized controlled trial.

Science.gov (United States)

Bansal, Virinder Kumar; Misra, Mahesh C; Rajan, Karthik; Kilambi, Ragini; Kumar, Subodh; Krishna, Asuri; Kumar, Atin; Pandav, Chandrakant S; Subramaniam, Rajeshwari; Arora, M K; Garg, Pramod Kumar

2014-03-01

The ideal method for managing concomitant gallbladder stones and common bile duct (CBD) stones is debatable. The currently preferred method is two-stage endoscopic stone extraction followed by laparoscopic cholecystectomy (LC). This prospective randomized trial compared the success and cost effectiveness of single- and two-stage management of patients with concomitant gallbladder and CBD stones. Consecutive patients with concomitant gallbladder and CBD stones were randomized to either single-stage laparoscopic CBD exploration and cholecystectomy (group 1) or endoscopic retrograde cholangiopancreatography (ERCP) for endoscopic extraction of CBD stones followed by LC (group 2). Success was defined as complete clearance of CBD and cholecystectomy by the intended method. Cost effectiveness was measured using the incremental cost-effectiveness ratio. Intention-to-treat analysis was performed to compare outcomes. From February 2009 to October 2012, 168 patients were randomized: 84 to the single-stage procedure (group 1) and 84 to the two-stage procedure (group 2). Both groups were matched with regard to demographic and clinical parameters. The success rates of laparoscopic CBD exploration and ERCP for clearance of CBD were similar (91.7 vs. 88.1 %). The overall success rate also was comparable: 88.1 % in group 1 and 79.8 % in group 2 (p = 0.20). Direct choledochotomy was performed in 83 of the 84 patients. The mean operative time was significantly longer in group 1 (135.7 ± 36.6 vs. 72.4 ± 27.6 min; p ≤ 0.001), but the overall hospital stay was significantly shorter (4.6 ± 2.4 vs. 5.3 ± 6.2 days; p = 0.03). Group 2 had a significantly greater number of procedures per patient (p gallbladder and CBD stones had similar success and complication rates, but the single-stage strategy was better in terms of shorter hospital stay, need for fewer procedures, and cost effectiveness.

Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 1; Fan Stage Design and Experimental Results

Science.gov (United States)

Suder, Kenneth L.; Prahst, Patricia S.; Thorp, Scott A.

2011-01-01

NASA s Fundamental Aeronautics Program is investigating turbine-based combined cycle (TBCC) propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. To this end, National Aeronautics and Space Administration (NASA) and General Electric (GE) teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10 ), fan speed (7 ), inlet mass flow (3.5 ), inlet pressure (8 ), and inlet temperature (3 ). In this paper, NASA has set out to characterize a TBCC engine fan stage aerodynamic performance and stability limits over a wide operating range including power-on and hypersonic-unique "windmill" operation. Herein, we will present the fan stage design, and the experimental test results of the fan stage operating from 15 to 100 percent corrected design speed. Whereas, in the companion paper, we will provide an assessment of NASA s APNASA code s ability to predict the fan stage performance and operability over a wide range of speed and bypass ratio.

Experimental study on an innovative multifunction heat pipe type heat recovery two-stage sorption refrigeration system

International Nuclear Information System (INIS)

Li, T.X.; Wang, R.Z.; Wang, L.W.; Lu, Z.S.

2008-01-01

An innovative multifunction heat pipe type sorption refrigeration system is designed, in which a two-stage sorption thermodynamic cycle based on two heat recovery processes was employed to reduce the driving heat source temperature, and the composite sorbent of CaCl 2 and activated carbon was used to improve the mass and heat transfer performances. For this test unit, the heating, cooling and heat recovery processes between two reactive beds are performed by multifunction heat pipes. The aim of this paper is to investigate the cycled characteristics of two-stage sorption refrigeration system with heat recovery processes. The two sub-cycles of a two-stage cycle have different sorption platforms though the adsorption and desorption temperatures are equivalent. The experimental results showed that the pressure evolutions of two beds are nearly equivalent during the first stage, and desorption pressure during the second stage is large higher than that in the first stage while the desorption temperatures are same during the two operation stages. In comparison with conventional two-stage cycle, the two-stage cycle with heat recovery processes can reduce the heating load for desorber and cooling load for adsorber, the coefficient of performance (COP) has been improved more than 23% when both cycles have the same regeneration temperature of 103 deg. C and the cooling water temperature of 30 deg. C. The advanced two-stage cycle provides an effective method for application of sorption refrigeration technology under the condition of low-grade temperature heat source or utilization of renewable energy

Performance Improvement for Two-Stage Single-Phase Grid-Connected Converters Using a Fast DC Bus Control Scheme and a Novel Synchronous Frame Current Controller

Directory of Open Access Journals (Sweden)

Bingzhang Li

2017-03-01

Full Text Available Two-stage single-phase grid-connected converters are widely used in renewable energy applications. Due to the presence of a second harmonic ripple across the DC bus voltage, it is very challenging to design the DC bus voltage control scheme in single-phase grid-connected inverters. The DC bus voltage controller must filter the ripple and balance a tradeoff between low harmonic distortion and high bandwidth. This paper presents a fast DC bus voltage controller, which uses a second order digital finite impulse response (FIR notch filter in conjunction with input power feedforward scheme to ensure the steady-state and dynamic performance. To gain the input power without extra hardware, a Kalman filter is incorporated to estimate the DC bus input current. At the same time, a modulation compensation strategy is implemented to eliminate the nonlinearity of the grid current control loop, which is caused by the DC bus voltage ripple. Moreover, a novel synchronous frame current controller for single-phase systems is also introduced, and its equivalent model in stationary frame has been derived. Simulation and experimental results are provided to verify the effective of the proposed control scheme.

Lengthening Temporalis Myoplasty for Single-Stage Smile Reconstruction in Children with Facial Paralysis.

Science.gov (United States)

Panossian, Andre

2016-04-01

Free muscle transfer for dynamic smile reanimation in facial paralysis is not always predictable with regard to cosmesis. Hospital stays range from 5 to 7 days. Prolonged operative times, longer hospital stays, and excessive cheek bulk are associated with free flap options. Lengthening temporalis myoplasty offers single-stage smile reanimation with theoretical advantages over free tissue transfer. From 2012 to 2014, 18 lengthening temporalis myoplasties were performed in 14 children for smile reconstruction. A retrospective chart review was completed for demographics, operative times, length of hospital stay, and perioperative complications. Fourteen consecutive patients with complete facial paralysis were included. Four patients underwent single-stage bilateral reconstruction, and 10 underwent unilateral procedures. Diagnoses included Möbius syndrome (n = 5), posterior cranial fossa tumors (n = 4), posttraumatic (n = 2), hemifacial microsomia (n = 1), and idiopathic (n = 2). Average patient age was 10.1 years. Average operative time was 410 minutes (499 minutes for bilateral lengthening temporalis myoplasty and 373 for unilateral lengthening temporalis myoplasty). Average length of stay was 3.3 days (4.75 days for bilateral lengthening temporalis myoplasty and 2.8 for unilateral lengthening temporalis myoplasty). Nine patients required minor revisions. Lengthening temporalis myoplasty is a safe alternative to free tissue transfer for dynamic smile reconstruction in children with facial paralysis. Limited donor-site morbidity, shorter operative times, and shorter hospital stays are some benefits over free flap options. However, revisions are required frequently secondary to tendon avulsions and adhesions. Therapeutic, IV.

Hearing rehabilitation with single-stage bilateral vibroplasty in a child with Franceschetti syndrome.

Science.gov (United States)

Sargsyan, Sona; Rahne, Torsten; Kösling, Sabrina; Eichler, Gerburg; Plontke, Stefan K

2014-05-01

Hearing is of utmost importance for normal speech and social development. Even children who have mild or unilateral permanent hearing loss may experience difficulties with understanding speech, as well as problems with educational and psycho-social development. The increasing advantages of middle-ear implant technologies are opening new perspectives for restoring hearing. Active middle-ear implants can be used in children and adolescents with hearing loss. In addition to the well-documented results for improving speech intelligibility and quality of hearing in sensorineural hearing loss active middle-ear implants are now successfully used in patients with conductive and mixed hearing loss. In this article we present a case of successful, single-stage vibroplasty, on the right side with the fixation of the FMT on the stapes and PORP CLiP vibroplasty on the left side in a 6-year-old girl with bilateral mixed hearing loss and multiple dyslalia associated with Franceschetti syndrome (mandibulofacial dysostosis). CT revealed bilateral middle-ear malformations as well as an atretic right and stenotic left external auditory canal. Due to craniofacial dysmorphia airway and (post)operative, management is significantly more difficult in patients with a Franceschetti syndrome which in this case favoured a single-stage bilateral procedure. No intra- or postoperative surgical complications were reported. The middle-ear implants were activated 4 weeks after surgery. In the audiological examination 6 months after surgery, the child showed 100% speech intelligibility with activated implants on each side.

QuantifyMe: An Open-Source Automated Single-Case Experimental Design Platform

Directory of Open Access Journals (Sweden)

Sara Taylor

2018-04-01

Full Text Available Smartphones and wearable sensors have enabled unprecedented data collection, with many products now providing feedback to users about recommended step counts or sleep durations. However, these recommendations do not provide personalized insights that have been shown to be best suited for a specific individual. A scientific way to find individualized recommendations and causal links is to conduct experiments using single-case experimental design; however, properly designed single-case experiments are not easy to conduct on oneself. We designed, developed, and evaluated a novel platform, QuantifyMe, for novice self-experimenters to conduct proper-methodology single-case self-experiments in an automated and scientific manner using their smartphones. We provide software for the platform that we used (available for free on GitHub, which provides the methodological elements to run many kinds of customized studies. In this work, we evaluate its use with four different kinds of personalized investigations, examining how variables such as sleep duration and regularity, activity, and leisure time affect personal happiness, stress, productivity, and sleep efficiency. We conducted a six-week pilot study (N = 13 to evaluate QuantifyMe. We describe the lessons learned developing the platform and recommendations for its improvement, as well as its potential for enabling personalized insights to be scientifically evaluated in many individuals, reducing the high administrative cost for advancing human health and wellbeing.

QuantifyMe: An Open-Source Automated Single-Case Experimental Design Platform.

Science.gov (United States)

Taylor, Sara; Sano, Akane; Ferguson, Craig; Mohan, Akshay; Picard, Rosalind W

2018-04-05

Smartphones and wearable sensors have enabled unprecedented data collection, with many products now providing feedback to users about recommended step counts or sleep durations. However, these recommendations do not provide personalized insights that have been shown to be best suited for a specific individual. A scientific way to find individualized recommendations and causal links is to conduct experiments using single-case experimental design; however, properly designed single-case experiments are not easy to conduct on oneself. We designed, developed, and evaluated a novel platform, QuantifyMe, for novice self-experimenters to conduct proper-methodology single-case self-experiments in an automated and scientific manner using their smartphones. We provide software for the platform that we used (available for free on GitHub), which provides the methodological elements to run many kinds of customized studies. In this work, we evaluate its use with four different kinds of personalized investigations, examining how variables such as sleep duration and regularity, activity, and leisure time affect personal happiness, stress, productivity, and sleep efficiency. We conducted a six-week pilot study ( N = 13) to evaluate QuantifyMe. We describe the lessons learned developing the platform and recommendations for its improvement, as well as its potential for enabling personalized insights to be scientifically evaluated in many individuals, reducing the high administrative cost for advancing human health and wellbeing.

Area G perimeter surface-soil and single-stage water sampling. Environmental surveillance for fiscal year 95. Progress report

International Nuclear Information System (INIS)

Childs, M.; Conrad, R.

1997-09-01

ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory (LANL) during FY 95 to characterize possible radionuclide movement out of Area G through surface water and entrained sediment runoff. Soil samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. The single-stage water samples were analyzed for tritium and plutonium isotopes. All radiochemical data was compared with analogous samples collected during FY 93 and 94 and reported in LA-12986 and LA-13165-PR. Six surface soils were also submitted for metal analyses. These data were included with similar data generated for soil samples collected during FY 94 and compared with metals in background samples collected at the Area G expansion area

Single-stage-to-orbit performance enhancement from take-off thrust augmentation

Science.gov (United States)

Galati, Terence; Elkins, Travis

1997-01-01

Thrust augmentation offers the Single Stage to Orbit (SSTO) space launch vehicle improved payload capability while reducing vehicle weight and cost. Optimization of vehicle configuration and flight profile are studied. Using a 612,000 kg Gross Lift Off Weight (GLOW) SSTO with three Castor® strap-on motors, payloads in excess of 18,000 kg to Low Earth Orbit (LEO) are achievable. Emphasis is placed on finding vehicle optimums in the 9,000 kg payload range to capture over 80% of commercial payloads. Strap-on boosters allow a small SSTO vehicle to fly with a mass fraction of only 0.88 and LOX/H2 engines operating at 445 sec vacuum specific impulse. Payload sensitivity due to variations of mass fraction, Isp and pitch rate are quantified.

Numerical Investigation and Experimental Demonstration of Chaos from Two-Stage Colpitts Oscillator in the Ultrahigh Frequency Range

DEFF Research Database (Denmark)

Bumeliene, S.; Tamasevicius, A.; Mykolaitis, G.

2006-01-01

A hardware prototype of the two-stage Colpitts oscillator employing the microwave BFG520 type transistors with the threshold frequency of 9 GHz and designed to operate in the ultrahigh frequency range (300–1000 MHz) is described. The practical circuit in addition to the intrinsic two-stage oscill......A hardware prototype of the two-stage Colpitts oscillator employing the microwave BFG520 type transistors with the threshold frequency of 9 GHz and designed to operate in the ultrahigh frequency range (300–1000 MHz) is described. The practical circuit in addition to the intrinsic two......-stage oscillator contains an emitter follower acting as a buffer and minimizing the influence of the load. The circuit is investigated both numerically and experimentally. Typical phase portraits, Lyapunov exponents, Lyapunov dimension and broadband continuous power spectra are presented. The main advantage...

Possible two-stage /sup 87/Sr evolution in the Stockdale Rhyolite

Energy Technology Data Exchange (ETDEWEB)

Compston, W.; McDougall, I. (Australian National Univ., Canberra. Research School of Earth Sciences); Wyborn, D. (Department of Minerals and Energy, Canberra (Australia). Bureau of Mineral Resources)

1982-12-01

The Rb-Sr total-rock data for the Stockdale Rhyolite, of significance for the Palaeozoic time scale, are more scattered about a single-stage isochron than expected from experimental error. Two-stage /sup 87/Sr evolution for several of the samples is explored to explain this, as an alternative to variation in the initial /sup 87/Sr//sup 86/Sr which is customarily used in single-stage dating models. The deletion of certain samples having very high Rb/Sr removes most of the excess scatter and leads to an estimate of 430 +- 7 m.y. for the age of extrusion. There is a younger alignment of Rb-Sr data within each sampling site at 412 +- 7 m.y. We suggest that the Stockdale Rhyolite is at least 430 m.y. old, that its original range in Rb/Sr was smaller than now observed, and that it experienced a net loss in Sr during later hydrothermal alteration at ca. 412 m.y.

Tissue Expansion Using Hyaluronic Acid Filler for Single-Stage Ear Reconstruction: A Novel Concept for Difficult Areas.

Science.gov (United States)

Inbal, Amir; Lemelman, Benjamin T; Millet, Eran; Greensmith, Andrew

2017-10-16

Auricular reconstruction is one of the most challenging procedures in plastic surgery. An adequate skin envelope is essential for cartilage framework coverage, yet few good options exist without additional surgery. We propose a novel method for minimally invasive tissue expansion, using hyaluronic acid (HA) filler to allow for single-stage ear reconstruction. To introduce the novel concept of HA filler for tissue expansion in ear reconstruction, and as an alternative to traditional expansion techniques. Macrolane is a large particle HA gel developed for large volume restoration. Expansion of the non-hair-bearing mastoid skin was performed in our clinic weekly or every other week. Final expansion was completed one week prior to reconstructive surgery. Tissue from one patient's expanded pocket was sent for histological analysis. Ten patients underwent single-stage auricular reconstruction with preoperative expansion. Injection sessions ranged from 7 to 13 (mean, 9.7). Mean injected volume per session was 2.03 mL per patient, for an average total of 19.8 mL (range, 14.5-30 mL). There were no major complications. One minor complication required removal of exposed wire from the antihelix in the office. Hematoxylin and eosin stain revealed similar histology to that seen with traditional expanders. This novel expansion technique using serial HA injections allowed for optimized skin coverage in single-stage ear reconstruction. The concept of tissue expansion using HA filler is a new frontier for research that may be applicable to other arenas of reconstruction. 4. © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

IL-6 is Upregulated in Late-Stage Disease in Monkeys Experimentally Infected with Trypanosoma brucei rhodesiense

Directory of Open Access Journals (Sweden)

Dawn Nyawira Maranga

2013-01-01

Full Text Available The management of human African trypanosomiasis (HAT is constrained by lack of simple-to-use diagnostic, staging, and treatment tools. The search for novel biomarkers is, therefore, essential in the fight against HAT. The current study aimed at investigating the potential of IL-6 as an adjunct parameter for HAT stage determination in vervet monkey model. Four adult vervet monkeys (Chlorocebus aethiops were experimentally infected with Trypanosoma brucei rhodesiense and treated subcuratively at 28 days after infection (dpi to induce late stage disease. Three noninfected monkeys formed the control group. Cerebrospinal fluid (CSF and blood samples were obtained at weekly intervals and assessed for various biological parameters. A typical HAT-like infection was observed. The late stage was characterized by significant (P<0.05 elevation of CSF IL-6, white blood cell count, and total protein starting 35 dpi with peak levels of these parameters coinciding with relapse parasitaemia. Brain immunohistochemical staining revealed an increase in brain glial fibrillary acidic protein expression indicative of reactive astrogliosis in infected animals which were euthanized in late-stage disease. The elevation of IL-6 in CSF which accompanied other HAT biomarkers indicates onset of parasite neuroinvasion and show potential for use as an adjunct late-stage disease biomarker in the Rhodesian sleeping sickness.

Interpretation of recovery Stage III in gold: a comment on the paper of A. Seeger and W. Frank

Energy Technology Data Exchange (ETDEWEB)

Sonnenberg, K.; Dedek, U.; Ehrhart, P.; Schilling, W. (Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Festkoerperforschung)

1983-09-01

The attempt of Seeger and Frank to reinterpret the annealing in recovery Stage III in gold in terms of the mobile single interstitial is discussed. Considering the experimental data of Stage III in irradiated samples and for the annealing stage observed in quenching samples around room temperature, it is concluded that the assignment of the recovery in these two stages to two different elementary defects is unjustified. It is further demonstrated that the interpretation of recovery Stage III by interstitial migration is in conflict with the direct observations of vacancies migrating in this stage and that the interpretation of the recovery measurements in radiation doped gold by the two interstitial model leads to inconsistencies. The attempt to interpret recovery Stage III in gold by interstitial migration must therefore be rejected and the activation energy of 0.71 eV measured for this stage must be attributed to the migration energy of single vacancies.

Experimental and numerical study on single-phase flow characteristics of natural circulation system with heated narrow rectangular channel under rolling motion condition

International Nuclear Information System (INIS)

Yu, Shengzhi; Wang, Jianjun; Yan, Ming; Yan, Changqi; Cao, Xiaxin

2017-01-01

Highlights: • The phasic difference between flow rate and frictional pressure drop is negligible. • Effect mechanism of rolling motion on flow behaviors of NC is interpreted. • The startup model is proposed and verified. • Steady-state correlations are feasible to predict transient resistance. • The in-house code can simulate instantaneous flow behaviors of NC correctly. - Abstract: Effects of rolling motion on flow characteristics in a natural circulation system were investigated experimentally and numerically. The numerical results from validated code were mainly used to provide detailed information for the discussion and analysis of experimental results. The results indicate that under rolling motion condition, the phasic difference between flow rate and frictional pressure drop of narrow rectangular channel is negligible. Angular acceleration is the eigenvalue for the effects of rolling motion on flow rate under single-phase natural circulation condition. When angular acceleration is approximately equal, even though either the angle or the period of rolling motion is different, peak, trough and time-averaged values of flow rate are approximately equal. Under rolling motion and single-phase natural circulation conditions, the phenomenon that dimensionless time-averaged mass flow rate is smaller than that under steady state condition is controlled by the nonlinear relationship between mass flow rate and the resistance of loop. The factor also causes the result that the absolute difference of dimensionless flow rate between peak and steady state is smaller than that between trough and steady state. The startup model which is proposed in present paper can be used to predict the flow characteristics of single-phase natural circulation system at startup stage of rolling motion favorably. The self-developed code can simulate instantaneous flow characteristics of single-phase natural circulation system under rolling motion and steady state conditions

Experimental investigation of shaping disturbance observer design for motion control of precision mechatronic stages with resonances

Science.gov (United States)

Yang, Jin; Hu, Chuxiong; Zhu, Yu; Wang, Ze; Zhang, Ming

2017-08-01

In this paper, shaping disturbance observer (SDOB) is investigated for precision mechatronic stages with middle-frequency zero/pole type resonance to achieve good motion control performance in practical manufacturing situations. Compared with traditional standard disturbance observer (DOB), in SDOB a pole-zero cancellation based shaping filter is cascaded to the mechatronic stage plant to meet the challenge of motion control performance deterioration caused by actual resonance. Noting that pole-zero cancellation is inevitably imperfect and the controller may even consequently become unstable in practice, frequency domain stability analysis is conducted to find out how each parameter of the shaping filter affects the control stability. Moreover, the robust design criterion of the shaping filter, and the design procedure of SDOB, are both proposed to guide the actual design and facilitate practical implementation. The SDOB with the proposed design criterion is applied to a linear motor driven stage and a voice motor driven stage, respectively. Experimental results consistently validate the effectiveness nature of the proposed SDOB scheme in practical mechatronics motion applications. The proposed SDOB design actually could be an effective unit in the controller design for motion stages of mechanical manufacture equipments.

Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop

International Nuclear Information System (INIS)

Ribando, R.J.

1979-01-01

A comparison is made between computed results and experimental data for a single-phase natural convection test in an experimental sodium loop. The test was conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) facility, an engineering-scale high temperature sodium loop at the Oak Ridge National Laboratory (ORNL) used for thermal-hydraulic testing of simulated Liquid Metal Fast Breeder Reactor (LMFBR) subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during the test was typical of decay heat levels. The test chosen for analysis in this paper was one of seven natural convection runs conducted in the facility using a variety of initial conditions and testing parameters. Specifically, in this test the bypass line was open to simulate a parallel heated assembly and the test was begun with a pump coastdown from a small initial forced flow. The computer program used to analyze the test, LONAC (LOw flow and NAtural Convection) is an ORNL-developed, fast-running, one-dimensional, single-phase, finite-difference model used for simulating forced and free convection transients in the THORS loop

Experimental quantum tossing of a single coin

International Nuclear Information System (INIS)

Nguyen, A T; Frison, J; Massar, S; Huy, K Phan

2008-01-01

The cryptographic protocol of coin tossing consists of two parties, Alice and Bob, who do not trust each other, but want to generate a random bit. If the parties use a classical communication channel and have unlimited computational resources, one of them can always cheat perfectly. If the parties use a quantum communication channel, there exist protocols such that neither party can cheat perfectly, although they may be able to significantly bias the coin. Here, we analyze in detail how the performance of a quantum coin tossing experiment should be compared to classical protocols, taking into account the inevitable experimental imperfections. We then report an all-optical fiber experiment in which a single coin is tossed whose randomness is higher than achievable by any classical protocol and present some easily realizable cheating strategies by Alice and Bob

A 5.4mW GPS CMOS quadrature front-end based on a single-stage LNA-mixer-VCO

DEFF Research Database (Denmark)

Liscidini, Amtonio; Mazzanti, Andrea; Tonietto, Riccardo

2006-01-01

A GPS RF front-end combines the LNA, mixer, and VCO in a single stage and can operate from a 1.2V supply. The chip is implemented in a 0.13um CMOS process and occupies 1.5mm2 active area. It consumes 5.4mW with a 4.8dB NF, 36dB gain, and a P1dB of -31dBm.......A GPS RF front-end combines the LNA, mixer, and VCO in a single stage and can operate from a 1.2V supply. The chip is implemented in a 0.13um CMOS process and occupies 1.5mm2 active area. It consumes 5.4mW with a 4.8dB NF, 36dB gain, and a P1dB of -31dBm....

A clinical case of single-stage correction of penetration combined orofacial defect with two microsurgical autografts

Directory of Open Access Journals (Sweden)

A. D. Kaprin

2015-01-01

Full Text Available After surgical treatment for locally advanced oral tumors with resection of soft tissues, mucosal membrane, and facial skeletal structures, there are penetration combined defects, removal of which is a challenge for reconstructive surgeons. Mandibular repair is one of the problems in the correction of combined oral defects. Surgeons use different grafts to remove mandibular defects. One-flap transplantation does not always solve all reconstruction problems and ensure the repair of the mucosal membrane, a soft-tissue component, skin integuments, and facial skeleton.The authors describe a clinical case of successful single-stage correction of penetration combined orofacial defect after resection of the tongue, mouth floor, en bloc resection of the lower jaw and mental soft tissues, bilateral cervical supramyochoroidal lymphadenectomy, stage LCL CM mandibular defect formation after J. Boyd, by using two microsurgical autografts (a peroneal skin-muscle-skin autograft and a radial skin-fascia one in a 39-year-old female patient clinically diagnosed with carcinoma of the left mandibular alveolar ridge mucosa, Stage IVA (T4аN0M0.The Department of Microsurgery, P.A. Herzen Moscow Oncology Research Institute, Ministry of Health of Russia, has gained experience in comprehensively correcting extensive combined maxillofacial defects with two or more grafts in 27 patients who underwent autografting with a total of 73 flaps. The most functionally incapacitating and life-incompatible defect was removed at Stage 1 of reconstructive treatment. Delayed reconstruction was made after a complex of specialized antitumor therapy and assessment of treatment results in the absence of progressive growth. A great problem during multi-stage defect correction is presented by the lack of recipient vessels after cervical lymphadenectomy, the presence of soft tissue scar changes, trismus, temporomandibular joint ankylosis, contractures and displacement of the edges of the

Maximizing the performance of a multiple-stage variable-throat venturi scrubber for particle collection

Science.gov (United States)

Muir, D. M.; Akeredolu, F.

The high collection efficiencies that are required nowadays to meet the stricter pollution control standards necessitate the use of high-energy scrubbers, such as the venturi scrubber, for the arrestment of fine particulate matter from exhaust gas streams. To achieve more energy-efficient particle collection, several venturi stages may be used in series. This paper is principally a theoretical investigation of the performance of a multiple-stage venturi scrubber, the main objective of the study being to establish the best venturi design configuration for any given set of operating conditions. A mathematical model is used to predict collection efficiency vs pressure drop relationships for particle sizes in the range 0.2-5.0 μm for one-, two-, three- and four-stage scrubbers. The theoretical predictions are borne out qualitatively by experimental work. The paper shows that the three-stage venturi produces the highest collection efficiencies over the normal operating range except for the collection of very fine particles at low pressure drops, when the single-stage venturi is best. The significant improvement in performance achieved by the three-stage venturi when compared with conventional single-stage operation increases as both the particle size and system pressure drop increase.

The first preliminary experiments on an 84 GHz gyrotron with a single-stage depressed collector

International Nuclear Information System (INIS)

Shimozuma, T.; Sato, M.; Takita, Y.

1997-10-01

We fabricated and tested an 84GHz gyrotron with a single-stage depressed collector. The gyrotron has a high-voltage insulating section made of a low loss silicon nitride composite. In this preliminary experiment in the depressed collector configuration, we obtained 591kW, 41% operation with a depression voltage of 22.5kV. Access to the higher efficiency region was inhibited by an increase in anode current. (author)

Single-stage intraoperative transhepatic biliary stenting in patients with unresectable hepatobiliary pancreatic tumors.

Science.gov (United States)

Iwasaki, Yoshimi; Kubota, Keiichi; Kita, Junji; Katoh, Masato; Shimoda, Mitsugi; Sawada, Tokihiko; Iso, Yukihiro

2013-02-01

The current study was conducted to evaluate the safety and utility of intraoperative transhepatic biliary stenting (ITBS) in patients with unresectable malignant biliary obstruction (UMBO) diagnosed intraoperatively. In this study, 50 patients who underwent ITBS for UMBO between April 2001 and May 2009 were retrospectively reviewed. For 26 patients who underwent preoperative percutaneous transhepatic biliary drainage (PTBD), the expandable metallic stent (EMS) was inserted intraoperatively by the PTBD route in a single stage. For 24 patients, the intrahepatic bile ducts were intentionally dilated by injection of saline via the endoscopic nasobiliary drainage or the percutaneous transhepatic gallbladder drainage route, and the puncture was performed under intraoperative ultrasound guidance followed by guidewire and catheter insertion. Thereafter, the EMS was placed in the same manner. The initial postoperative complications and long-term results of ITBS were evaluated. In all cases, ITBS was technically successful. Stenting alone was performed in 22 patients and stenting combined with other procedures in 28 patients. Hospital mortality occurred for three patients (6 %), and complication-related mortality occurred in two cases (4 %). There were nine cases (18 %) of postoperative complications. The median survival time was 179 days, and the EMS patency time was 137 days. During the follow-up period, EMS occlusion occurred in 23 cases (46 %). Best supportive care was a significant independent risk factor for early mortality within 100 days after ITBS (p = 0.020, odds ratio, 9.398). Single-stage ITBS is feasible for palliation of UMBO and seems to have a low complication rate.

Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction.

Science.gov (United States)

Fogel, Mark A; Li, Christine; Elci, Okan U; Pawlowski, Tom; Schwab, Peter J; Wilson, Felice; Nicolson, Susan C; Montenegro, Lisa M; Diaz, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Mascio, Christopher; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2017-02-14

Patients with a single ventricle experience a high rate of brain injury and adverse neurodevelopmental outcome; however, the incidence of brain abnormalities throughout surgical reconstruction and their relationship with cerebral blood flow, oxygen delivery, and carbon dioxide reactivity remain unknown. Patients with a single ventricle were studied with magnetic resonance imaging scans immediately prior to bidirectional Glenn (pre-BDG), before Fontan (BDG), and then 3 to 9 months after Fontan reconstruction. One hundred sixty-eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age, 4.8±1.7 months), 118 BDG (2.9±1.4 years), and 54 after Fontan (2.4±1.0 years). Nonacute ischemic white matter changes on T2-weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontan compared with pre-BDG patients ( P <0.05). BDG patients had significantly higher cerebral blood flow than did Fontan patients. The odds of discovering brain injury with adjustment for surgical stage as well as ≥2 coexisting lesions within a patient decreased (63%-75% and 44%, respectively) with increasing amount of cerebral blood flow ( P <0.05). In general, there was no association of oxygen delivery (except for ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury. Significant brain abnormalities are commonly present in patients with a single ventricle, and detection of these lesions increases as children progress through staged surgical reconstruction, with multiple coexisting lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater cerebral blood flow than did Fontan patients and that an inverse association exists of various indexes of cerebral blood flow with these brain lesions. However, CO 2 reactivity and oxygen delivery (with 1 exception) were not associated with brain lesion development. URL: http

Quality Appraisal of Single-Subject Experimental Designs: An Overview and Comparison of Different Appraisal Tools

Science.gov (United States)

Wendt, Oliver; Miller, Bridget

2012-01-01

Critical appraisal of the research literature is an essential step in informing and implementing evidence-based practice. Quality appraisal tools that assess the methodological quality of experimental studies provide a means to identify the most rigorous research suitable for evidence-based decision-making. In single-subject experimental research,…

Experimental and kinetics studies of aromatic hydrogenation in a two-stage hydrotreating process using NiMo/Al{sub 2}O{sub 3} and NiW/Al{sub 2}O{sub 3} catalysts

Energy Technology Data Exchange (ETDEWEB)

Owusu-Boakye, A.; Dalai, A.K.; Ferdous, D. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemical Engineering, Catalysis and Chemical Reaction Engineering Laboratories; Adjaye, J. [Syncrude Canada Ltd., Edmonton, AB (Canada)

2006-10-15

The degree of hydrogenation of aromatics in light gas oil (LGO) feed from Athabasca bitumen was examined using a two-stage process. Experiments were conducted in a trickle-bed reactor using 2 catalysts, namely nickel molybdenum alumina (NiMo/Al{sub 2}O{sub 3}) in stage one and nickel tungsten alumina (NiW/Al{sub 2}O{sub 3}) in the second stage. NiMo/Al{sub 2}O{sub 3} was used in the first stage in order to remove nitrogen and sulphur containing heteroatoms. NiW/Al{sub 2}O{sub 3} was used in the second stage for saturation of the aromatic rings in the hydrocarbon species. The catalysts were used under a range of temperature and pressure condition. Temperature and liquid hourly space velocity ranged from 350 to 390 degrees C and 1.0 to 1.5 per hour, respectively. Pressure was kept constant at 11.0 MPa for all experiments. Reaction time results from the two-stage process were compared with those from a single-stage where hydrotreating was performed over NiMo/AL{sub 2}O{sub 3}. Product samples from different feedstocks were analyzed with respect to sulfur, nitrogen and aromatic content. Gasoline selectivity and kinetic parameters for hydrodesulphurization (HDS) or hydrodenitrogenation (HDN) reactions for the feed materials were also compared. The effect of hydrogen sulphide (H{sub 2}S) inhibition on aromatics hydrogenation (HDA) was also kinetically modelled using the Langmuir-Hinshelwood approach. Kinetic analysis of the single-stage hydrotreating process showed that HDA and HDS activities were slowed by the presence of hydrogen sulphide that is produced as a by-product of the HDS process. However, with inter-stage removal of hydrogen sulphide in the two-stage process, significant improvement of the HDA and HDS activities were noted. It was concluded that the experimental data was successfully predicted by the Langmuir-Hinshelwood kinetic models. 27 refs., 4 tabs., 8 figs.

Self-Excited Single-Stage Power Factor Correction Driving Circuit for LED Lighting

Directory of Open Access Journals (Sweden)

Yong-Nong Chang

2014-01-01

Full Text Available This pa\tper proposes a self-excited single-stage high power factor LED lighting driving circuit. Being featured with power factor correction capability without needing any control devices, the proposed circuit structure is with low cost and suitable for commercial production. The power factor correction function is accomplished by using inductor in combination with a half-bridge quasi resonant converter to achieve active switching and yield out voltage regulation according to load requirement. Furthermore, the zero-voltage switching in the half-bridge converter can be attained to promote the overall performance efficiency of the proposed circuit. Finally, the validity and production availability of the proposed circuit will be verified as well.

Spectral Characteristic Based on Fabry—Pérot Laser Diode with Two-Stage Optical Feedback

International Nuclear Information System (INIS)

Wu Jian-Wei; Nakarmi Bikash

2013-01-01

An optical device, consisting of a multi-mode Fabry—Pérot laser diode (MMFP-LD) with two-stage optical feedback, is proposed and experimentally demonstrated. The results show that the single-mode output with side-mode suppression ratio (SMSR) of ∼21.7 dB is attained by using the first-stage feedback. By using the second-stage feedback, the SMSR of single-mode operation could be increased to ∼28.5 dB while injection feedback power of −29 dBm is introduced into the laser diode. In the case of up to −29 dBm feedback power, the outcome SMSR is rapidly decayed to a very low level so that an obvious multi-mode operation in the output spectrum could be achieved at the feedback power level of −15.5 dBm. Thus, a transition between single- and multi-mode operations could be flexibly controlled by adjusting the injected power in the second-stage feedback system. Additionally, in the case of injection locking, the outcome SMSR and output power at the locked wavelength are as high as ∼50 dB and ∼5.8 dBm, respectively

Shape Optimization of the Assisted Bi-directional Glenn surgery for stage-1 single ventricle palliation

Science.gov (United States)

Verma, Aekaansh; Shang, Jessica; Esmaily-Moghadam, Mahdi; Wong, Kwai; Marsden, Alison

2016-11-01

Babies born with a single functional ventricle typically undergo three open-heart surgeries starting as neonates. The first of these stages (BT shunt or Norwood) has the highest mortality rates of the three, approaching 30%. Proceeding directly to a stage-2 Glenn surgery has historically demonstrated inadequate pulmonary flow (PF) & high mortality. Recently, the Assisted Bi-directional Glenn (ABG) was proposed as a promising means to achieve a stable physiology by assisting the PF via an 'ejector pump' from the systemic circulation. We present preliminary parametrization and optimization results for the ABG geometry, with the goal of increasing PF. To limit excessive pressure increases in the Superior Vena Cava (SVC), the SVC pressure is included as a constraint. We use 3-D finite element flow simulations coupled with a single ventricle lumped parameter network to evaluate PF & the pressure constraint. We employ a derivative free optimization method- the Surrogate Management Framework, in conjunction with the OpenDIEL framework to simulate multiple simultaneous evaluations. Results show that nozzle diameter is the most important design parameter affecting ABG performance. The application of these results to patient specific situations will be discussed. This work was supported by an NSF CAREER award (OCI1150184) and by the XSEDE National Computing Resource.

Experimental investigations on solar heating/heat pump systems for single family houses

DEFF Research Database (Denmark)

Andersen, Elsa; Perers, Bengt

In the period 2013-2017 the project “Experimental investigations on solar heat pump systems for single family houses” is carried out at Department of Civil Engineering, Technical University of Denmark. The aim of this project is to increase the knowledge of the heat and mass transfer in the combi...

An operational protocol for facilitating start-up of single-stage autotrophic nitrogen-removing reactors based on process stoichiometry

DEFF Research Database (Denmark)

Mutlu, Ayten Gizem; Vangsgaard, Anna Katrine; Sin, Gürkan

2013-01-01

Start-up and operation of single-stage nitritation–anammox sequencing batch reactors (SBRs) for completely autotrophic nitrogen removal can be challenging and far from trivial. In this study, a step-wise procedure is developed based on stoichiometric analysis of the process performance from...

The sublimation kinetics of GeSe single crystals

Science.gov (United States)

Irene, E. A.; Wiedemeier, H.

1975-01-01

The sublimation kinetics of (001) oriented GeSe single crystal platelets was studied by high-temperature mass spectroscopy, quantitative vacuum microbalance techniques, and hot stage optical microscopy. For a mean experimental temperature of 563 K, the activation enthalpy and entropy are found to equal 32.3 kcal/mole and 19.1 eu, respectively. The vaporization coefficient is less than unity for the range of test temperatures, and decreases with increasing temperature. The combined experimental data are correlated by means of a multistep surface adsorption mechanism.

Experimental investigation of two-stage thermoelectric generator system integrated with phase change materials

DEFF Research Database (Denmark)

Ahmadi Atouei, Saeed; Ranjbar, Ali Akbar; Rezaniakolaei, Alireza

2017-01-01

this amount of voltage just for 2100 s. Therefore, the proposed design makes TEG systems more suitable for wireless sensor applications when the heat source does not provide steady thermal energy. In this study, four different patterns of thermal power applied to the TTEG system are considered. These patterns...... experimentally. In the first stage, a TEG module installed between a phase change material (PCM) heat sink, as cooling system, and an electrical heater, as the heat source. Because of the inherent characteristics of PCMs to save the thermal energy as latent heat, the PCM heat sink is used as the heat source...

Experimental research of inclined-micro-fin flat tube on single phase convection heat transfer

International Nuclear Information System (INIS)

Fan Guangming; Sun Zhongning; Wang Meng

2011-01-01

The experimental research of heat transfer and flow resistance characteristics of single phase water in four inclined-micro-fin flat tubes with different physical dimensions was conducted. At the same time,suitable criteria were selected to evaluate the efficiency of inclined-micro-fin flat tubes within the experimental scope and the optimal working region was determined. The results indicate that inclined-micro-fin flat tubes can greatly enhance the single-phase heat transfer in turbulent flow and the maximum heat transfer coefficient attains to 5.9 times of that in smooth tube. The quantities of heat transfer for inclined-micro-fin flat tubes are three times higher than that of smooth tube with the same of heat exchange area and pump power. (authors)

Effects of commonly used chemical fertilizers on development of free-living stages of Haemonchus contortus in experimentally infected pasture

Directory of Open Access Journals (Sweden)

Tapas Kumar Roul

2017-07-01

Full Text Available Aim: The effects of N-P-K fertilizers in the form of urea, single super phosphate and muriate of potash on development of free-living stages of Haemonchus contortus were studied. Materials and Methods: Five parasite free experimental plots of 1 mx1 m area, each of paddy leaves (15-day-old and an equal number of Cynodon dactylon grass were infested with about 10x104 eggs/ml phosphate buffer saline along with the application of the calculated amount of fertilizers solution. On the 10th day of posttreatment, the pasture was cut, processed, larvae recovered by Baermann method and counted, which was expressed as number of L3 per kg dry matter (DM of pasture. Results: The average recovered population of L3 of H. contortus per kg DM varied significantly (p0.05. Conclusion: This study shown that when N-P-K fertilizers administered at recommended level, significantly reduced larval translation of H. contortus minimizing pasture infectivity for the free range grazing animals.

Experimental test of the strongly nonclassical character of a noisy squeezed single-photon state

DEFF Research Database (Denmark)

Jezek, M.; Tipsmark, A.; Dong, R.

2012-01-01

We experimentally verify the quantum non-Gaussian character of a conditionally generated noisy squeezed single-photon state with a positive Wigner function. Employing an optimized witness based on probabilities of squeezed vacuum and squeezed single-photon states, we prove that the state cannot...... be expressed as a mixture of Gaussian states. In our experiment, the non-Gaussian state is generated by conditional subtraction of a single photon from a squeezed vacuum state. The state is probed with a homodyne detector and the witness is determined by averaging a suitable pattern function over the measured...

An operation protocol for facilitating start-up of single-stage autotrophic nitrogen removing reactors based on process stoichiometry

DEFF Research Database (Denmark)

Mutlu, A. Gizem; Vangsgaard, Anna Katrine; Sin, Gürkan

2012-01-01

Start-up and operation of single-stage nitritation/anammox reactor employing complete autotrophic nitrogen can be difficult. Keeping the performance criteria and monitoring the microbial community composition may not be easy or fast enough to take action on time. In this study, a control strategy...

Experimental Evidence for Quantum Interference and Vibrationally Induced Decoherence in Single-Molecule Junctions

Science.gov (United States)

Ballmann, Stefan; Härtle, Rainer; Coto, Pedro B.; Elbing, Mark; Mayor, Marcel; Bryce, Martin R.; Thoss, Michael; Weber, Heiko B.

2012-08-01

We analyze quantum interference and decoherence effects in single-molecule junctions both experimentally and theoretically by means of the mechanically controlled break junction technique and density-functional theory. We consider the case where interference is provided by overlapping quasidegenerate states. Decoherence mechanisms arising from electronic-vibrational coupling strongly affect the electrical current flowing through a single-molecule contact and can be controlled by temperature variation. Our findings underline the universal relevance of vibrations for understanding charge transport through molecular junctions.

The effectiveness of a single-stage versus traditional three-staged protocol of hospital disinfection at eradicating vancomycin-resistant Enterococci from frequently touched surfaces.

Science.gov (United States)

Friedman, N Deborah; Walton, Aaron L; Boyd, Sarah; Tremonti, Christopher; Low, Jillian; Styles, Kaylene; Harris, Owen; Alfredson, David; Athan, Eugene

2013-03-01

Environmental contamination is a reservoir for vancomycin-resistant enterococcus (VRE) in hospitals. Environmental sampling of surfaces was undertaken anytime before disinfection and 1 hour after disinfection utilizing a sodium dichloroisocyanurate-based, 3-staged protocol (phase 1) or benzalkonium chloride-based, single-stage clean (phase 2). VRE colonization and infection rates are presented from 2010 to 2011, and audits of cleaning completeness were also analyzed. Environmental samples collected before disinfection were significantly more likely to be contaminated with VRE during phase 1 than phase 2: 25.2% versus 4.6%, respectively; odds ratio (OR), 7.01 (P benzalkonium chloride-based product for disinfection. This reduction in VRE may be due to a new disinfection product, more attention to the thoroughness of cleaning, or other supplementary efforts in our institution. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Vaginal Radical Trachelectomy for early stage cervical cancer. Results of the Danish National Single Center Strategy

DEFF Research Database (Denmark)

Hauerberg, L; Høgdall, C; Loft, A

2015-01-01

OBJECTIVE: To present and evaluate an unselected national single center strategy with fertility preserving trachelectomy in cervical cancer. In 2003 nationwide single-center referral of women for trachelectomies was agreed upon between all Danish departments performing cervical cancer surgery...... a total of 77 pregnancies. Of the 72 women 40 were referred to fertility treatment. First and second trimester miscarriage rates were 21.6% and 2.7%, respectively. A total of 53 children were born of which 41 were delivered after gestational week 34. CONCLUSION: This unselected national single center...... of 120 unselected consecutive VRTs were assessed. To obtain complete follow-up about fertility treatment, pregnancy and obstetric outcome the women filled out an electronic questionnaire. Median follow-up: 55.7 months. RESULTS: 85.8% of the patients had stage IB1 disease, 68.3% squamous cell carcinomas...

Design and analysis of a single stage to orbit nuclear thermal rocket reactor engine

Energy Technology Data Exchange (ETDEWEB)

Labib, Satira, E-mail: Satira.Labib@duke-energy.com; King, Jeffrey, E-mail: kingjc@mines.edu

2015-06-15

Graphical abstract: - Highlights: • Three NTR reactors are optimized for the single stage launch of 1–15 MT payloads. • The proposed rocket engines have specific impulses in excess of 700 s. • Reactivity and submersion criticality requirements are satisfied for each reactor. - Abstract: Recent advances in the development of high power density fuel materials have renewed interest in nuclear thermal rockets (NTRs) as a viable propulsion technology for future space exploration. This paper describes the design of three NTR reactor engines designed for the single stage to orbit launch of payloads from 1 to 15 metric tons. Thermal hydraulic and rocket engine analyses indicate that the proposed rocket engines are able to reach specific impulses in excess of 800 s. Neutronics analyses performed using MCNP5 demonstrate that the hot excess reactivity, shutdown margin, and submersion criticality requirements are satisfied for each NTR reactor. The reactors each consist of a 40 cm diameter core packed with hexagonal tungsten cermet fuel elements. The core is surrounded by radial and axial beryllium reflectors and eight boron carbide control drums. The 40 cm long reactor meets the submersion criticality requirements (a shutdown margin of at least $1 subcritical in all submersion scenarios) with no further modifications. The 80 and 120 cm long reactors include small amounts of gadolinium nitride as a spectral shift absorber to keep them subcritical upon submersion in seawater or wet sand following a launch abort.

Design and analysis of a single stage to orbit nuclear thermal rocket reactor engine

International Nuclear Information System (INIS)

Labib, Satira; King, Jeffrey

2015-01-01

Graphical abstract: - Highlights: • Three NTR reactors are optimized for the single stage launch of 1–15 MT payloads. • The proposed rocket engines have specific impulses in excess of 700 s. • Reactivity and submersion criticality requirements are satisfied for each reactor. - Abstract: Recent advances in the development of high power density fuel materials have renewed interest in nuclear thermal rockets (NTRs) as a viable propulsion technology for future space exploration. This paper describes the design of three NTR reactor engines designed for the single stage to orbit launch of payloads from 1 to 15 metric tons. Thermal hydraulic and rocket engine analyses indicate that the proposed rocket engines are able to reach specific impulses in excess of 800 s. Neutronics analyses performed using MCNP5 demonstrate that the hot excess reactivity, shutdown margin, and submersion criticality requirements are satisfied for each NTR reactor. The reactors each consist of a 40 cm diameter core packed with hexagonal tungsten cermet fuel elements. The core is surrounded by radial and axial beryllium reflectors and eight boron carbide control drums. The 40 cm long reactor meets the submersion criticality requirements (a shutdown margin of at least $1 subcritical in all submersion scenarios) with no further modifications. The 80 and 120 cm long reactors include small amounts of gadolinium nitride as a spectral shift absorber to keep them subcritical upon submersion in seawater or wet sand following a launch abort

QuantifyMe: An Open-Source Automated Single-Case Experimental Design Platform †

Science.gov (United States)

Sano, Akane; Ferguson, Craig; Mohan, Akshay; Picard, Rosalind W.

2018-01-01

Smartphones and wearable sensors have enabled unprecedented data collection, with many products now providing feedback to users about recommended step counts or sleep durations. However, these recommendations do not provide personalized insights that have been shown to be best suited for a specific individual. A scientific way to find individualized recommendations and causal links is to conduct experiments using single-case experimental design; however, properly designed single-case experiments are not easy to conduct on oneself. We designed, developed, and evaluated a novel platform, QuantifyMe, for novice self-experimenters to conduct proper-methodology single-case self-experiments in an automated and scientific manner using their smartphones. We provide software for the platform that we used (available for free on GitHub), which provides the methodological elements to run many kinds of customized studies. In this work, we evaluate its use with four different kinds of personalized investigations, examining how variables such as sleep duration and regularity, activity, and leisure time affect personal happiness, stress, productivity, and sleep efficiency. We conducted a six-week pilot study (N = 13) to evaluate QuantifyMe. We describe the lessons learned developing the platform and recommendations for its improvement, as well as its potential for enabling personalized insights to be scientifically evaluated in many individuals, reducing the high administrative cost for advancing human health and wellbeing. PMID:29621133

Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop. [LMFBR

Energy Technology Data Exchange (ETDEWEB)

Ribando, R.J.

1979-01-01

A comparison is made between computed results and experimental data for a single-phase natural convection test in an experimental sodium loop. The test was conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) facility, an engineering-scale high temperature sodium loop at the Oak Ridge National Laboratory (ORNL) used for thermal-hydraulic testing of simulated Liquid Metal Fast Breeder Reactor (LMFBR) subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during the test was typical of decay heat levels. The test chosen for analysis in this paper was one of seven natural convection runs conducted in the facility using a variety of initial conditions and testing parameters. Specifically, in this test the bypass line was open to simulate a parallel heated assembly and the test was begun with a pump coastdown from a small initial forced flow. The computer program used to analyze the test, LONAC (LOw flow and NAtural Convection) is an ORNL-developed, fast-running, one-dimensional, single-phase, finite-difference model used for simulating forced and free convection transients in the THORS loop.

Two-stage single-phase grid-connected photovoltaic system with reduced complexity

Science.gov (United States)

da Silva, Cintia S.; Motta, Filipe R.; Tofoli, Fernando L.

2011-06-01

This article presents a grid-connected photovoltaic (PV) system using the classical DC-DC buck converter, which is responsible for stepping down the resulting voltage from several series-connected panels. Besides, the structure provides high power factor operation by injecting a quasi-sinusoidal current into the grid, with near no displacement in relation to the line voltage at the point of common coupling among the PV system and the loads. A CSI employing thyristors is cascaded with the DC-DC stage so that AC voltage results. The inverter output voltage level is adjusted by using a low-frequency transformer, which also provides galvanic isolation. The proposed system is described as mathematical approach and design guidelines are presented, providing an overview of the topology. An experimental prototype is also implemented, and relevant results to validate the proposal are discussed.

Design and cold-air test of single-stage uncooled turbine with high work output

Science.gov (United States)

Moffitt, T. P.; Szanca, E. M.; Whitney, W. J.; Behning, F. P.

1980-01-01

A solid version of a 50.8 cm single stage core turbine designed for high temperature was tested in cold air over a range of speed and pressure ratio. Design equivalent specific work was 76.84 J/g at an engine turbine tip speed of 579.1 m/sec. At design speed and pressure ratio, the total efficiency of the turbine was 88.6 percent, which is 0.6 point lower than the design value of 89.2 percent. The corresponding mass flow was 4.0 percent greater than design.

Modified classification and single-stage microsurgical repair of posttraumatic infected massive bone defects in lower extremities.

Science.gov (United States)

Yang, Yun-fa; Xu, Zhong-he; Zhang, Guang-ming; Wang, Jian-wei; Hu, Si-wang; Hou, Zhi-qi; Xu, Da-chuan

2013-11-01

Posttraumatic infected massive bone defects in lower extremities are difficult to repair because they frequently exhibit massive bone and/or soft tissue defects, serious bone infection, and excessive scar proliferation. This study aimed to determine whether these defects could be classified and repaired at a single stage. A total of 51 cases of posttraumatic infected massive bone defect in lower extremity were included in this study. They were classified into four types on the basis of the conditions of the bone defects, soft tissue defects, and injured limb length, including Type A (without soft tissue defects), Type B (with soft tissue defects of 10 × 20 cm or less), Type C (with soft tissue defects of 10 × 20 cm or more), and Type D (with the limb shortening of 3 cm or more). Four types of single-stage microsurgical repair protocols were planned accordingly and implemented respectively. These protocols included the following: Protocol A, where vascularized fibular graft was implemented for Type A; Protocol B, where vascularized fibular osteoseptocutaneous graft was implemented for Type B; Protocol C, where vascularized fibular graft and anterior lateral thigh flap were used for Type C; and Protocol D, where limb lengthening and Protocols A, B, or C were used for Type D. There were 12, 33, 4, and 2 cases of Types A, B, C, and D, respectively, according to this classification. During the surgery, three cases of planned Protocol B had to be shifted into Protocol C; however, all microsurgical repairs were completed. With reference to Johner-Wruhs evaluation method, the total percentage of excellent and good results was 82.35% after 6 to 41 months of follow-up. It was concluded that posttraumatic massive bone defects could be accurately classified into four types on the basis of the conditions of bone defects, soft tissue coverage, and injured limb length, and successfully repaired with the single-stage repair protocols after thorough debridement. Thieme Medical

The influence of the design matrix on treatment effect estimates in the quantitative analyses of single-subject experimental design research.

Science.gov (United States)

Moeyaert, Mariola; Ugille, Maaike; Ferron, John M; Beretvas, S Natasha; Van den Noortgate, Wim

2014-09-01

The quantitative methods for analyzing single-subject experimental data have expanded during the last decade, including the use of regression models to statistically analyze the data, but still a lot of questions remain. One question is how to specify predictors in a regression model to account for the specifics of the design and estimate the effect size of interest. These quantitative effect sizes are used in retrospective analyses and allow synthesis of single-subject experimental study results which is informative for evidence-based decision making, research and theory building, and policy discussions. We discuss different design matrices that can be used for the most common single-subject experimental designs (SSEDs), namely, the multiple-baseline designs, reversal designs, and alternating treatment designs, and provide empirical illustrations. The purpose of this article is to guide single-subject experimental data analysts interested in analyzing and meta-analyzing SSED data. © The Author(s) 2014.

A single blood test adjusted for different liver fibrosis targets improves fibrosis staging and especially cirrhosis diagnosis.

Science.gov (United States)

Calès, Paul; Boursier, Jérôme; Oberti, Frédéric; Moal, Valérie; Fouchard Hubert, Isabelle; Bertrais, Sandrine; Hunault, Gilles; Rousselet, Marie Christine

2018-04-01

Fibrosis blood tests are usually developed using significant fibrosis, which is a unique diagnostic target; however, these tests are employed for other diagnostic targets, such as cirrhosis. We aimed to improve fibrosis staging accuracy by simultaneously targeting biomarkers for several diagnostic targets. A total of 3,809 patients were included, comprising 1,012 individuals with chronic hepatitis C (CHC) into a derivation population and 2,797 individuals into validation populations of different etiologies (CHC, chronic hepatitis B, human immunodeficiency virus/CHC, nonalcoholic fatty liver disease, alcohol) using Metavir fibrosis stages as reference. FibroMeter biomarkers were targeted for different fibrosis-stage combinations into classical scores by logistic regression. Independent scores were combined into a single score reflecting Metavir stages by linear regression and called Multi-FibroMeter Version Second Generation (V2G). The primary objective was to combine the advantages of a test targeted for significant fibrosis (FibroMeter V2G ) with those of a test targeted for cirrhosis (CirrhoMeter V2G ). In the derivation CHC population, we first compared Multi-FibroMeter V2G to FibroMeter V2G and observed significant increases in the cirrhosis area under the receiver operating characteristic curve (AUROC), Obuchowski index (reflecting all fibrosis-stage AUROCs), and classification metric (six classes expressed as a correctly classified percentage) and a nonsignificant increase in significant fibrosis AUROC. Thereafter, we compared it to CirroMeter V2G and observed a nonsignificant increase in the cirrhosis AUROC. In all 3,809 patients, respective accuracies for Multi-FibroMeter V2G and FibroMeter V2G were the following: cirrhosis AUROC, 0.906 versus 0.878 ( P fibrosis AUROC, 0.833 versus 0.832 ( P = 0.366). Multi-FibroMeter V2G had the highest correlation with the area of portoseptal fibrosis and the highest reproducibility over time. Correct classification rates

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.

Experimental study on heavy-ion single event effect on nanometer DDR SRAM

International Nuclear Information System (INIS)

Luo Yinhong; Zhang Fengqi; Guo Hongxia; Zhou Hui; Wang Yanping; Zhang Keying

2013-01-01

Single event effect experimental study on 90 nm and 65 nm DDR SRAM were carried out, single event upset (SEU) cross section was discussed as a function of several parameters such as feature size, test pattern, incidence angle, supply voltage. Key influence factors and effect rule were analyzed. Feasibility of the current test method was discussed. Results indicate that, SEU cross section reduces as technologies scale down; the influence of test pattern and power supply on SEU cross section is small; tilt angle increases SEU cross section due to multiple upset increasement. The applicability of cosine tilt test method is correlative to ion species and linear energy transfer (LET) values. (authors)

3 kW single stage all-fiber Yb-doped single-mode fiber laser for highly reflective and highly thermal conductive materials processing

Science.gov (United States)

Ikoma, S.; Nguyen, H. K.; Kashiwagi, M.; Uchiyama, K.; Shima, K.; Tanaka, D.

2017-02-01

A 3 kW single stage all-fiber Yb-doped single-mode fiber laser with bi-directional pumping configuration has been demonstrated. Our newly developed high-power LD modules are employed for a high available pump power of 4.9 kW. The length of the delivery fiber is 20 m which is long enough to be used in most of laser processing machines. An output power of 3 kW was achieved at a pump power of 4.23 kW. The slope efficiency was 70%. SRS was able to be suppressed at the same output power by increasing ratio of backward pump power. The SRS level was improved by 5dB when 57% backward pump ratio was adopted compared with the case of 50%. SRS was 35dB below the laser power at the output power of 3 kW even with a 20-m delivery fiber. The M-squared factor was 1.3. Single-mode beam quality was obtained. To evaluate practical utility of the 3 kW single-mode fiber laser, a Bead-on-Plate (BoP) test onto a pure copper plate was executed. The BoP test onto a copper plate was made without stopping or damaging the laser system. That indicates our high power single-mode fiber lasers can be used practically in processing of materials with high reflectivity and high thermal conductivity.

Experimental study of the single electron response of the DELPHI Barrel RICH MWPC's

International Nuclear Information System (INIS)

Dracos, M.

1989-01-01

We present herewith the results of an experimental study of the multiwire proportionnal chambers (MWPC's) used in the Barrel RICH particle identifier of the LEP-DELPHI experiment. Emphasis is given to the problem of detection efficiency and to the measurements of the charge induced by a single photoelectron

Randomization and Data-Analysis Items in Quality Standards for Single-Case Experimental Studies

Science.gov (United States)

Heyvaert, Mieke; Wendt, Oliver; Van den Noortgate, Wim; Onghena, Patrick

2015-01-01

Reporting standards and critical appraisal tools serve as beacons for researchers, reviewers, and research consumers. Parallel to existing guidelines for researchers to report and evaluate group-comparison studies, single-case experimental (SCE) researchers are in need of guidelines for reporting and evaluating SCE studies. A systematic search was…

Dynamic variability of the heading-flowering stages of single rice in China based on field observations and NDVI estimations.

Science.gov (United States)

Zhang, Zhao; Song, Xiao; Chen, Yi; Wang, Pin; Wei, Xing; Tao, Fulu

2015-05-01

Although many studies have indicated the consistent impact of warming on the natural ecosystem (e.g., an early flowering and prolonged growing period), our knowledge of the impacts on agricultural systems is still poorly understood. In this study, spatiotemporal variability of the heading-flowering stages of single rice was detected and compared at three different scales using field-based methods (FBMs) and satellite-based methods (SBMs). The heading-flowering stages from 2000 to 2009 with a spatial resolution of 1 km were extracted from the SPOT/VGT NDVI time series data using the Savizky-Golay filtering method in the areas in China dominated by single rice of Northeast China (NE), the middle-lower Yangtze River Valley (YZ), the Sichuan Basin (SC), and the Yunnan-Guizhou Plateau (YG). We found that approximately 52.6 and 76.3 % of the estimated heading-flowering stages by a SBM were within ±5 and ±10 days estimation error (a root mean square error (RMSE) of 8.76 days) when compared with those determined by a FBM. Both the FBM data and the SBM data had indicated a similar spatial pattern, with the earliest annual average heading-flowering stages in SC, followed by YG, NE, and YZ, which were inconsistent with the patterns reported in natural ecosystems. Moreover, diverse temporal trends were also detected in the four regions due to different climate conditions and agronomic factors such as cultivar shifts. Nevertheless, there were no significant differences (p > 0.05) between the FBM and the SBM in both the regional average value of the phenological stages and the trends, implying the consistency and rationality of the SBM at three scales.

Experimental study of single-electron loss by Ar+ ions in rare-gas atoms

Science.gov (United States)

Reyes, P. G.; Castillo, F.; Martínez, H.

2001-04-01

Absolute differential and total cross sections for single-electron loss were measured for Ar+ ions on rare-gas atoms in the laboratory energy range of 1.5 to 5.0 keV. The electron loss cross sections for all the targets studied are found to be in the order of magnitude between 10-19 and 10-22 cm2, and show a monotonically increasing behaviour as a function of the incident energy. The behaviour of the total single-electron loss cross sections with the atomic target number, Zt, shows different dependences as the collision energy increases. In all cases the present results display experimental evidence of saturation in the single-electron loss cross section as the atomic number of the target increases.

Evaluation of single-stage adjustable strabismus surgery under conscious sedation

Directory of Open Access Journals (Sweden)

Sharma Pradeep

2009-01-01

Full Text Available Purpose: To evaluate the feasibility and stability of ocular alignment after single-stage adjustable strabismus surgery (SSASS performed under topical anesthesia. Materials and Methods: Forty-five patients of concomitant exodeviations were randomized into three groups of 15 cases each and were operated with three different techniques: Group I - conventional surgery, Group II - two-stage adjustable suture technique with suture adjustment performed 6h postoperatively and Group III- SSASS under topical anesthesia and intravenous conscious sedation with midazolam and fentanyl. Intraoperative suture adjustment was done by giving a cross target to the patient on the ceiling at the end of the procedure. Surgical results were compared among the three groups at three months follow-up. Intraoperative hemodynamic parameters and patients′ experience of the surgery (by questionnaire were also compared. Results: Mean preoperative deviation for distance in Groups I, II, III was -41.67 prism diopter (pd ±9.0, -38.93 pd ±11.05 and -41.87 pd ±8.91 ( P =0.6 respectively. At three months, mean correction achieved for distance was +31.87 pd ±11.71, +35.47 pd ±10.86 and +42.80 pd ±10.71 respectively which was significantly different between Group III and Group I ( P =0.03. Intraoperatively all hemodynamic parameters remained stable and comparable ( P =0. 5 in all groups. Intraoperative pain ( P < 0.001 and time taken for surgery ( P < 0.001 was more in the SSASS group. Amount of exodrift was 10-12 pd, comparable in all three groups ( P = 0.5. Conclusions: SSASS, performed under topical anesthesia, is safe and has better outcomes than conventional recession-resection surgery for concomitant exodeviation. An overcorrection of about 10-12 pd is recommended to check the exodrift and achieve stable alignment.

A Proposal Of Simulation Model Of A Wind-Steering System For Sailing Yachts, Based On Single-Stage Servo-Pendulum Coupled With Main Rudder

Directory of Open Access Journals (Sweden)

Piętak Andrzej

2015-04-01

Full Text Available The aim of this study was to investigate possible application of fast design prototyping methods for wind-steering systems used in offshore sailing yachts. The development of such methods would help to speed up the construction work and reduce the scope of necessary experimental research, prior to implementation of the system. In the present work, based on an analysis of existing designs of windvane systems, a preliminary selection of the system configuration has been undertaken, in terms of a compromise between efficiency, performance, and design complexity. Construction design of a single-stage, servo – pendulum system, has been developed by using the Autodesk Inventor design package. Next, based on the design data, a simulation model of the system, has been produced by using Matlab - Simulink software and SimMechanics library. The model was further verified in terms of kinematics mapping with the use of Matlab visualization tools.

Alterations in biomechanical properties and microstructure of colon wall in early-stage experimental colitis.

Science.gov (United States)

Gong, Xiaohui; Xu, Xiaojuan; Lin, Sisi; Cheng, Yu; Tong, Jianhua; Li, Yongyu

2017-08-01

The aim of the current study was to investigate the effects of early-stage dextran sodium sulfate (DSS)-induced mouse colitis on the biomechanical properties and microstructure of colon walls. In the present study, colitis was induced in 8-week-old mice by the oral administration of DSS, and then 10 control and 10 experimental colitis samples were harvested. Uniaxial tensile tests were performed to measure the ultimate tensile strength and ultimate stretches of colon tissues. In addition, histological investigations were performed to characterize changes in the microstructure of the colon wall following treatment. The results revealed that the ultimate tensile stresses were 232±33 and 183±25 kPa for the control and DSS groups, respectively (P=0.001). Ultimate stretches at rupture for the control and DSS groups were 1.43±0.04 and 1.51±0.06, respectively (P=0.006). However, there was no statistically significant difference in tissue stiffness between the two groups. Histological analysis demonstrated high numbers of inflammatory cells infiltrated into the stroma in the DSS group, leading to significant submucosa edema. Hyperplasia was also identified in the DSS-treated submucosa, causing a disorganized microstructure within the colon wall. Furthermore, a large number of collagen fibers in the DSS-treated muscular layer were disrupted, and fiber bundles were thinner when compared with the control group. In conclusion, early-stage experimental colitis alters the mechanical properties and microstructural characteristics of the colon walls, further contributing to tissue remodeling in the pathological process.

High efficiency 40 K single-stage Stirling-type pulse tube cryocooler

Science.gov (United States)

Wu, X. L.; Chen, L. B.; Pan, C. Z.; Cui, C.; Wang, J. J.; Zhou, Y.

2017-12-01

A high efficiency single-stage Stirling-type coaxial pulse tube cryocooler (SPTC) operating at around 40 K has been designed, built and tested. The double-inlet and the inertance tubes together with the gas reservoir were adopted as the phase shifters. Under the conditions of 2.5 MPa charging pressure and 30 Hz operating frequency, the prototype has achieved a no-load temperature of 23.8 K with 330 W of electric input power at a rejection temperature of 279 K. When the input power increases to 400 W, it can achieve a cooling capacity of 4.7 W/40 K while rejecting heat at 279 K yielding an efficiency of 7.02% relative to Carnot. It achieves a cooling capacity of 5 W/40 K with an input power of 450 W. It takes 10 minutes for the SPTC to cool to its no-load temperature of 40 K from 295 K.

First experimental observation of double-photon Compton scattering using single gamma detector

International Nuclear Information System (INIS)

Sandhu, B.S.; Saddi, M.B.; Singh, B.; Ghumman, B.S.

2003-01-01

Full text: The phenomenon of double-photon Compton scattering has been successfully observed using single gamma detector, a technique avoiding the use of complicated slow-fast coincidence set-up used till now for observing this higher order process. Here doubly differentiated collision cross-section integrated over direction of one of the two final photons, the direction of other one being kept fixed, has been measured experimentally for 0.662 MeV incident gamma photons. The energy spectra of the detected photons are observed as a long tail to the single-photon Compton line on the lower side of the full energy peak in the recorded scattered energy spectrum. The present results are in agreement with theory of this process

Single Stage To Orbit Minimum Requirements Through Numerical Simulation

Science.gov (United States)

Teixeira, E.

It is widely known that producing a single stage to orbit spacecraft is no easy task. It is also understood that it will be the first steady step towards spacecraft that operate in much the same way as today's airliners. This, in turn is believed to decrease the economical cost of reaching space through more efficient use of a single vehicle and higher launch rates. Space is then open to the common man, either through tourism or as a transportation medium. This paper is yet another study on the physical requirements of a SSTO spacecraft. It will begin with simple assumptions and gradually build up accuracy until reaching the use of a numerical simulation tool, so as to provide the necessary insight into it. The curvature of the Earth, its gravitational field, the exhaust pressure loss and atmospheric drag are a few of the considerations that the simulation takes into account. No attention was give to the actual details of the spacecraft such as propulsion type(s), winged or lifting body (aerodynamics), active or passive cooling (thermodynamics), stability and control. All these subsystems are considered to be included into the construction mass. The drag model is a simple textbook approximation and the propulsion force is given by a hypothetical propellant and engine so as to produce the assumed range of specific impulse. Even the construction mass is supposed to be futuristic so as to reach the lowest specified values. Not only vertical take-off will be simulated but also horizontal launching from altitude (from a towing aircraft, for example). The result of the paper shows the relationship between the construction mass and the specific impulse of a given spacecraft if it is to reach low earth orbit. This paper thus aims at bringing some light to the controversial discussion of how to make these vehicles a reality. The simulation program (Matlab) is available to students.

No Randomization? No Problem: Experimental Control and Random Assignment in Single Case Research

Science.gov (United States)

Ledford, Jennifer R.

2018-01-01

Randomization of large number of participants to different treatment groups is often not a feasible or preferable way to answer questions of immediate interest to professional practice. Single case designs (SCDs) are a class of research designs that are experimental in nature but require only a few participants, all of whom receive the…

Bias Corrections for Standardized Effect Size Estimates Used with Single-Subject Experimental Designs

Science.gov (United States)

Ugille, Maaike; Moeyaert, Mariola; Beretvas, S. Natasha; Ferron, John M.; Van den Noortgate, Wim

2014-01-01

A multilevel meta-analysis can combine the results of several single-subject experimental design studies. However, the estimated effects are biased if the effect sizes are standardized and the number of measurement occasions is small. In this study, the authors investigated 4 approaches to correct for this bias. First, the standardized effect…

Experimental demonstration of a simple displacement sensor based on a bent single-mode–multimode–single-mode fiber structure

International Nuclear Information System (INIS)

Wu, Qiang; Semenova, Yuliya; Wang, Pengfei; Hatta, Agus Muhamad; Farrell, Gerald

2011-01-01

A simple displacement sensor based on a bent single-mode–multimode–single-mode (SMS) fiber structure is proposed and experimentally investigated. The sensor offers a wider displacement range, not limited by the risk of fiber breakage, as well as a three-fold increase in displacement sensitivity by comparison with a straight SMS structure sensor. This sensor can be interrogated by either an optical spectral analyzer (OSA) or a ratiometric interrogation system: (1) if interrogated by an OSA assuming a resolution of 1 pm, it has a sensitivity of 28.2 nm for a displacement measurement range from 0 to 280 µm; (2) if interrogated by a ratiometric interrogation system, it has worst and best case resolutions of 556 and 38 nm, respectively, for a displacement measurement range from 0 to 520 µm

Experimental investigation of a two-step transport refrigerator with R744; Experimentelle Untersuchung einer zweistufigen Trans-portkaelteanlage mit R744

Energy Technology Data Exchange (ETDEWEB)

Moehlenkamp, A.; Lemke, N.; Koehler, J. [TU Braunschweig (Germany). Inst. fuer Thermodynamik

2012-07-01

Until now, predominantly closed, single-stage refrigeration cycles are used in the transport refrigeration. Two-stage cooling circuits facilitate new circuit variations and result in a significant increase in the energy efficiency in comparison to single-stage refrigeration cycles. This is especially true for the natural refrigerant R744 (carbon dioxide). Due to the thermodynamic features in the range of transport refrigeration R744 provides an alternative to the predominantly used synthetic refrigerants R404A and R410A with an enhanced global warming potential.The authors of the contribution under consideration report on a two-stage laboratory system which enables experimental investigations of transport refrigeration and is operated with the coolant R744. This two-stage laboratory system with an internal heat exchanger on a medium-pressure level continuously supplies coldness for normal refrigeration and deep-freezing. The design of the laboratory plant is based on a reference system for motor vehicles and thus corresponds to the practical conditions. First experimental results at an ambient temperature of 30 Celsius are presented and discussed.

Wide-bandwidth bilateral control using two-stage actuator system

International Nuclear Information System (INIS)

Kokuryu, Saori; Izutsu, Masaki; Kamamichi, Norihiro; Ishikawa, Jun

2015-01-01

This paper proposes a two-stage actuator system that consists of a coarse actuator driven by a ball screw with an AC motor (the first stage) and a fine actuator driven by a voice coil motor (the second stage). The proposed two-stage actuator system is applied to make a wide-bandwidth bilateral control system without needing expensive high-performance actuators. In the proposed system, the first stage has a wide moving range with a narrow control bandwidth, and the second stage has a narrow moving range with a wide control bandwidth. By consolidating these two inexpensive actuators with different control bandwidths in a complementary manner, a wide bandwidth bilateral control system can be constructed based on a mechanical impedance control. To show the validity of the proposed method, a prototype of the two-stage actuator system has been developed and basic performance was evaluated by experiment. The experimental results showed that a light mechanical impedance with a mass of 10 g and a damping coefficient of 2.5 N/(m/s) that is an important factor to establish good transparency in bilateral control has been successfully achieved and also showed that a better force and position responses between a master and slave is achieved by using the proposed two-stage actuator system compared with a narrow bandwidth case using a single ball screw system. (author)

MRI-guided single fraction ablative radiotherapy for early-stage breast cancer : a brachytherapy versus volumetric modulated arc therapy dosimetry study

NARCIS (Netherlands)

Charaghvandi, Ramona K; den Hartogh, Mariska D; van Ommen, Anne-Mar L N; de Vries, Wilfred J H; Scholten, Vincent; Moerland, Rien; Philippens, Mariëlle E P; Schokker, Rogier I; van Vulpen, Marco; van Asselen, B; van den Bongard, Desirée H J G

2015-01-01

BACKGROUND AND PURPOSE: A radiosurgical treatment approach for early-stage breast cancer has the potential to minimize the patient's treatment burden. The dosimetric feasibility for single fraction ablative radiotherapy was evaluated by comparing volumetric modulated arc therapy (VMAT) with an

Experimental study of micro-milling mechanism and surface quality of a nickel-based single crystal superalloy

Energy Technology Data Exchange (ETDEWEB)

Gao, Qi; Gong, Yadong; Zhou, Yun Guang; Wen, Xue Long [School of Mechanical Engineering and Automation, Northeastern University, Shenyang (China)

2017-01-15

Micro-milling is widely used as a method for machining of micro-parts with high precision and efficiency. Taking the nickel-based single-crystal superalloy DD98 as the research object, the crystal characteristics of single-crystal materials were analysed, and the removal mechanism of single-crystal micro-milled parts was described. Based on molecular dynamics, a simulation model for nickel-based single-crystal superalloy DD98 micro-milling was established. Based on the response surface method of central composite design, the influences of spindle speed, feed rate, and milling depth on the surface roughness were examined, and a second-order regression model of the DD98 surface roughness was established. Using analysis of variance and the residuals of the model, a significant influence on surface roughness was found in the following order from large to small: Feed rate, spindle speed, and milling depth. Comparisons were conducted between the micro-milling experimental values and the predicted model values for different process parameters. The results show that the model fit is relatively high, and the adaptability is good. Scanning electron microscopy analysis of the micro-milling surfaces was performed to verify the slip and the removal mechanism of single-crystal materials. These results offer a theoretical reference and experimental basis for micro-milling of single-crystal materials.

Investigation of a bistable dual-stage vibration isolator under harmonic excitation

International Nuclear Information System (INIS)

Yang, Kai; Huang, Hai; Harne, R L; Wang, K W

2014-01-01

This study explores the steady-state performance of a dual-stage vibration isolator, which is configured by a bistable oscillator and a linear oscillator. The potential force of the bistable stage comprises negative linear and positive cubic nonlinear stiffnesses such that the two restoring force contributions may counterbalance to minimize dynamic force transmission. By applying a first-order harmonic balance, it is predicted that the bistable dual-stage isolator may significantly outperform an equivalent pure linear dual-stage isolator. This conclusion is verified through a series of numerical investigations. Following a parametric study, design guidelines are detailed to achieve performance improvements. Then, the ‘valley’ response, which is the special phenomenon of the bistable dual-stage isolator due to the counterbalance of the negative linear and positive nonlinear potential forces, is revealed and quantitatively explained. Numerical studies demonstrate the role of initial conditions, and it is shown that the likelihood of beneficial single periodic valley and intra-well responses for isolation purposes can be increased by greater bistable stage damping. Finally, a bistable dual-stage isolator prototype is developed and tested, and the numerical and experimental results verify the theoretical predictions. (paper)

Optics of two-stage photovoltaic concentrators with dielectric second stages

Science.gov (United States)

Ning, Xiaohui; O'Gallagher, Joseph; Winston, Roland

1987-04-01

Two-stage photovoltaic concentrators with Fresnel lenses as primaries and dielectric totally internally reflecting nonimaging concentrators as secondaries are discussed. The general design principles of such two-stage systems are given. Their optical properties are studied and analyzed in detail using computer ray trace procedures. It is found that the two-stage concentrator offers not only a higher concentration or increased acceptance angle, but also a more uniform flux distribution on the photovoltaic cell than the point focusing Fresnel lens alone. Experimental measurements with a two-stage prototype module are presented and compared to the analytical predictions.

Optics of two-stage photovoltaic concentrators with dielectric second stages.

Science.gov (United States)

Ning, X; O'Gallagher, J; Winston, R

1987-04-01

Two-stage photovoltaic concentrators with Fresnel lenses as primaries and dielectric totally internally reflecting nonimaging concentrators as secondaries are discussed. The general design principles of such two-stage systems are given. Their optical properties are studied and analyzed in detail using computer ray trace procedures. It is found that the two-stage concentrator offers not only a higher concentration or increased acceptance angle, but also a more uniform flux distribution on the photovoltaic cell than the point focusing Fresnel lens alone. Experimental measurements with a two-stage prototype module are presented and compared to the analytical predictions.

Nucleation Mechanisms of Aromatic Polyesters, PET, PBT, and PEN, on Single-Wall Carbon Nanotubes: Early Nucleation Stages

Directory of Open Access Journals (Sweden)

Adriana Espinoza-Martínez

2012-01-01

Full Text Available Nucleation mechanisms of poly(ethylene terephthalate (PET, poly(butylene terephthalate (PBT, and poly(ethylene naphthalate (PEN on single-wall carbon nanotubes (SWNTs are proposed, based on experimental evidence, theoretical epitaxy analysis, and semiempirical quantum chemical calculations. In order to elucidate early nucleation stages polyester-coated nanotubes were obtained from highly diluted solutions. High-resolution transmission electron microscopy (HRTEM revealed helical morphologies for PET/SWNTs and PEN/SWNTs and the formation of lobules with different orientations for PBT/SWNTs. To explain the morphological behavior one model was proposed based on crystallographic interactions, that is, epitaxy. Theoretical epitaxy calculations indicated that epitaxy is not possible from the strict epitaxy point of view. Instead, aromatic self-assembly mechanism was proposed based on π-π interactions and the chirality of the nanotube. It was proposed that the mechanism implies two steps to produce helical or lobular morphologies with different orientations. In the first step polymer chains were approached, aligned parallel to the nanotube axis and adsorbed due to electrostatic interactions and the flexibility of the molecule. However, due to π-π interactions between the aromatic rings of the polymer and the nanotube, in the second step chains reoriented on the nanotube surface depending on the chirality of the nanotube. The mechanism was supported by semi-empirical calculations.

Metoidioplasty as a single stage sex reassignment surgery in female transsexuals: Belgrade experience.

Science.gov (United States)

Djordjevic, Miroslav L; Stanojevic, Dusan; Bizic, Marta; Kojovic, Vladimir; Majstorovic, Marko; Vujovic, Svetlana; Milosevic, Alexandar; Korac, Gradimir; Perovic, Sava V

2009-05-01

Metoidioplasty represents one of the variants of phalloplasty in female transsexuals. Its main characteristic is that it is a one-stage procedure. It involves lengthening and straightening of hypertrophied clitoris to create a neophallus, urethral lengthening to enable voiding while standing, and scrotal reconstruction with insertion of testicle prostheses. Our aim is to describe our technique and highlight its advantages. Between September 2002 and April 2007, 82 female transsexuals, aged 18-54 years (mean age 31) underwent one-stage metoidioplasty. Clitoris is lengthened and straightened by division of clitoral ligaments and short urethral plate. Urethroplasty is done with combined buccal mucosa graft and genital skin flaps. Scrotum is created from labia majora in which two testicle prostheses are inserted. Simultaneously, female genitalia are removed. Patients' personal satisfaction about sensitivity and length of neophallus, possibility to void in standing position, real length of reconstructed urethra as well as complication rate comparing to other published data. The median follow-up was 32 months (range 14-69). The mean neophallic length was 5.7 cm (range 4-10). Voiding in standing position was reported in all patients, while dribbling and spraying were noticed in 23 cases and solved spontaneously. There were two urethral strictures and seven fistulas that required secondary minor revision. All patients reported preserved sensation and normal postoperative erection. Testicle prostheses rejection was not observed in any of the patients. Metoidioplasty is a single-stage and time-saving procedure. It could be an alternative to total phalloplasty in female transsexuals who do not wish to have sexual intercourse. Also, it represents a first step in cases where additional augmentation phalloplasty is required.

Iodine-125 seed brachytherapy for early stage prostate cancer: a single-institution review

International Nuclear Information System (INIS)

Zuber, Simon; Weiß, Susan; Baaske, Dieter; Schöpe, Michael; Stevens, Simon; Bodis, Stephan; Zwahlen, Daniel R

2015-01-01

We are reporting the five-year biochemical control, toxicity profile and dosimetric parameters using iodine-125 low dose rate brachytherapy (BT) as monotherapy for early stage prostate cancer at a single institution. Between April 2006 and December 2010, 169 men with early stage prostate cancer were treated with BT. Biochemical failure was defined using the Phoenix definition (nadir + 2 ng/mL). Treatment-related morbidities, including urinary, rectal and sexual function, were measured, applying the International Prostate Symptom Score (IPSS), the 7-grade Quality of Life Scale (QoL) and medical status, the International Consultation on Incontinence Modular Questionnaire (ICIQ), the International Index of Erectile Function (IIEF-5) and the Common Terminology Criteria for Adverse Events (CTCAE v4.03). Seed migration and loss, dosimetric parameters and learning effects were also analyzed. Medium follow-up time was 50 months (range, 1–85 months). The five-year biochemical failure rate was 7%. Acute proctitis rates were 19% (grade 1) and 1% (grade 2), respectively. The overall incidence of incontinence was 19% (mild), 16% (moderate) and < 1% (severe). An increase in IPSS ≥ 5 points was detected in 59% of patients, with 38% regaining their baseline. Seed dislocation was found in 24% of patients and correlated with D90 and V100. A learning curve was found for seed migration, D90 and V100. QoL correlated with the general health condition of patient, incontinence symptoms and IPSS. BT for early stage prostate cancer offers excellent five-year biochemical control with low toxicities. QoL aspects are favorable. A learning curve was detected for procedural aspects but its impact on patient relevant endpoints remains inconclusive

Evaluation of the therapeutic effect of potassium permanganate at early stages of an experimental acute infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus)

Science.gov (United States)

The efficacy of potassium permanganate (KMnO4) against early stages of an experimental acute infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus) was evaluated. Fish were experimentally challenged, by waterborne exposure for 2 h to F. columnare after cutaneous abrasion, an...

Experimental determination of entanglement with a single measurement.

Science.gov (United States)

Walborn, S P; Souto Ribeiro, P H; Davidovich, L; Mintert, F; Buchleitner, A

2006-04-20

Nearly all protocols requiring shared quantum information--such as quantum teleportation or key distribution--rely on entanglement between distant parties. However, entanglement is difficult to characterize experimentally. All existing techniques for doing so, including entanglement witnesses or Bell inequalities, disclose the entanglement of some quantum states but fail for other states; therefore, they cannot provide satisfactory results in general. Such methods are fundamentally different from entanglement measures that, by definition, quantify the amount of entanglement in any state. However, these measures suffer from the severe disadvantage that they typically are not directly accessible in laboratory experiments. Here we report a linear optics experiment in which we directly observe a pure-state entanglement measure, namely concurrence. Our measurement set-up includes two copies of a quantum state: these 'twin' states are prepared in the polarization and momentum degrees of freedom of two photons, and concurrence is measured with a single, local measurement on just one of the photons.

BAGHEERA: A new experimental facility at CEA / Valduc for actinides studies under high dynamic loading

Science.gov (United States)

Roy, G.; Llorca, F.; Lanier, G.; Lamalle, S.; Beaulieu, J.; Antoine, P.; Martinuzzi, P.

2006-08-01

This paper is a technical presentation about a new experimental facility recently developed at CEA/Valduc, BAGHEERA, a French acronym for “Hopkinson And High Speed Experiments Glove Box”. This facility is used since mid-2003 to characterize the physical and mechanical behaviour of actinides under high dynamic loadings. For this purpose, four basic experimental devices are confined inside a single glove box: a 50 mm bore diameter single stage light gas gun, two compression and torsion split Hopkinson bars (SHPB and TSHB respectively) and a Taylor test device (TTD). Design and technical data on the experimental equipment are addressed, with a particular emphasis on the gas gun specific features due to actinide applications.

Single-gene prognostic signatures for advanced stage serous ovarian cancer based on 1257 patient samples.

Science.gov (United States)

Zhang, Fan; Yang, Kai; Deng, Kui; Zhang, Yuanyuan; Zhao, Weiwei; Xu, Huan; Rong, Zhiwei; Li, Kang

2018-04-16

We sought to identify stable single-gene prognostic signatures based on a large collection of advanced stage serous ovarian cancer (AS-OvCa) gene expression data and explore their functions. The empirical Bayes (EB) method was used to remove the batch effect and integrate 8 ovarian cancer datasets. Univariate Cox regression was used to evaluate the association between gene and overall survival (OS). The Database for Annotation, Visualization and Integrated Discovery (DAVID) tool was used for the functional annotation of genes for Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The batch effect was removed by the EB method, and 1257 patient samples were used for further analysis. We selected 341 single-gene prognostic signatures with FDR matrix organization, focal adhesion and DNA replication which are closely associated with cancer. We used the EB method to remove the batch effect of 8 datasets, integrated these datasets and identified stable prognosis signatures for AS-OvCa.

EXPERIMENTAL RESEARCH OF REGENERATIVE FEATURES IN BONE TISSUES AROUND IMPLANTS AFTER ONE-STAGE BILATERAL TOTAL HIP REPLACEMENT

Directory of Open Access Journals (Sweden)

V. M. Mashkov

2012-01-01

Full Text Available Objective: to research the specific features of regenerative processes of bone tissue around implants after one-stage bilateral total hip replacement in experiment. Material and methods: 27 total hip replacement operations have been performed in 18 rabbits of breed "chinchilla" to which bipolar femoral endoprosthesis made of titanic alloy PT-38, one type-size, with friction pair metal-on-metal and neck-shaft angle 165 degrees have been implanted: total unilateral hip replacement operations have been performed in 9 animals (control group, one-stage bilateral total hip replacement operations have been performed in 9 animals (experimental group. During research they have been on radiological and clinical checking-up. After the experiment the animals had histological tests of the tissues around endoprosthesis components. Results and conclusions: After one-stage bilateral total hip replacement in early terms of research more expressed changes of bone tissue in the form of its thinning and decompaction were found around implants. One-stage bilateral total hip replacement did not essentially influence on the speed of osteogenesis around endoprothesis components in comparison with unilateral total hip replacement, so in late terms of observation in both groups the fixing of endoprothesis components did not differ.

Performance Enhancement in L-Band Edfa Through Dual Stage Technique

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S. W. Harun and H. Ahmad

2012-10-01

Full Text Available An experiment on gain enhancement in the long wavelength band erbium doped fiber amplifier (L-band EDFA is demonstrated. It uses a dual stage technique with dual forward pumping scheme. Compared to a conventional single stage amplifier, the small signal gain for 1580nm signal can be improved by 5.5dB without paying much noise figure penalty. The corresponding noise figure penalty was 0.3dB due to the insertion loss of the optical isolator. The optimum pump power ratio for the first pump is experimentally determined to be 33%. The maximum gain improvement of 8.3dB was obtained at a signal wavelength of 1568nm while signal and total pump powers were fixed at -30dBm and 92mW, respectively. The employment of dual stage amplifier system seems to play an important role in the development of practical L-band EDFA from the perspective of economical usage of pump power.Key Words:  erbium doped fibre; optical amplifier; L-band EDFA; dual stage EDFA; amplified spontaneous emission

Symposium on single cell analysis and genomic approaches, Experimental Biology 2017 Chicago, Illinois, April 23, 2017.

Science.gov (United States)

Coller, Hilary A

2017-09-01

Emerging technologies for the analysis of genome-wide information in single cells have the potential to transform many fields of biology, including our understanding of cell states, the response of cells to external stimuli, mosaicism, and intratumor heterogeneity. At Experimental Biology 2017 in Chicago, Physiological Genomics hosted a symposium in which five leaders in the field of single cell genomics presented their recent research. The speakers discussed emerging methodologies in single cell analysis and critical issues for the analysis of single cell data. Also discussed were applications of single cell genomics to understanding the different types of cells within an organism or tissue and the basis for cell-to-cell variability in response to stimuli. Copyright © 2017 the American Physiological Society.

A CFD Analysis of Steam Flow in the Two-Stage Experimental Impulse Turbine with the Drum Rotor Arrangement

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Yun Kukchol

2016-01-01

Full Text Available 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.

COOLING STAGES OF CRYOGENIC SYSTEMS

OpenAIRE

Троценко, А. В.

2011-01-01

The formalized definition for cooling stage of low temperature system is done. Based on existing information about the known cryogenic unit cycles the possible types of cooling stages are single out. From analyses of these stages their classification by various characteristics is suggested. The results of thermodynamic optimization of final throttle stage of cooling, which are used as working fluids helium, hydrogen and nitrogen, are shown.

In vivo effect of single oral dose of artemether against early juvenile stages of Schistosoma mansoni Egyptian strain.

Science.gov (United States)

El-Beshbishi, Samar N; Taman, Amira; El-Malky, Mohamed; Azab, Manar S; El-Hawary, Amira K; El-Tantawy, Dina A

2013-10-01

The current treatment and control of schistosomiasis, rely on a single drug, praziquantel, although, it has minor activity against juvenile stages of the parasite. Studies have shown that artemether (ART) exhibits effects against juveniles of Schistosoma mansoni Liberian and Puerto Rican strains, Schistosoma japonicum and Schistosoma haematobium. Aiming to assess the in vivo activity of single oral dose of ART against early juvenile stages of S. mansoni Egyptian strain, this study was established. Mice were treated with ART (400 mg/kg) at two time points evenly spaced over the period of larval development (7 and 21 days post-infection; pi), and a third treatment point (day 49 pi) was included to elucidate when susceptibility decreases. Administration of ART on day 7 pi reduced the total worm burden by 85.94%. The greatest reductions were seen when treatment was given on day 21 pi, with total and female worm burden reductions of 91.52% and 90.57%, respectively, and cessation of oviposition. Similar dose given on day 49 pi reduced total worm burden by 55.17% and female worm burden by 66.51%. Moreover, it induced significant reduction in the tissue egg load and significant alterations in the oogram pattern with decreased immature eggs and increased dead eggs. Antipathological activities were evident in significant reductions in granulomata count and diameter. In conclusion, ART exhibits major in vivo schistosomicidal effects against the early larval migratory stages of S. mansoni Egyptian strain, mainly the 21-day old schistosomula, hence preventing disease progression and morbidity. Copyright © 2013 Elsevier Inc. All rights reserved.

Design and construction of a single unit multi-function optical encoder for a six-degree-of-freedom motion error measurement in an ultraprecision linear stage

International Nuclear Information System (INIS)

Lee, ChaBum; Kim, Gyu Ha; Lee, Sun-Kyu

2011-01-01

This paper presents the method of a six-degree-of-freedom (DOF) posture measurement in a linear stage by employing a single unit of an optical encoder. The proposed optical encoder was constructed to simultaneously measure the posture along the traveling axis; angular errors, pitch, yaw and roll; and translational errors, ΔX, ΔY and ΔZ. It consists of a diffractive optical element, a corner cube, four separate two-dimensional position-sensitive detectors, four photodiodes and auxiliary optics components. The circularly polarizing interferometric technique was integrated to measure the displacement of the stage along the traveling axis in a robust manner and the resolution was estimated to be less than 0.4 nm. Two types of stages were employed for the measurement implementation, the piezoelectric transducer-driven and the ballscrew-driven, and they were feedback-controlled for the traveling axis, respectively. With a single travel of the stage, it provided a six-DOF motion error with a high resolution, less than 0.03 arcsec, 20 nm and 0.4 nm for angular errors, ΔY and ΔZ, and ΔX, respectively, at the same time. As a result, it was seen that motion errors of the stage have relevance to the driving mechanism and the whole construction of the stage

Outcomes of single-stage total arch replacement via clamshell incision

Directory of Open Access Journals (Sweden)

Ishizaka Toru

2011-09-01

Full Text Available Abstract Background Treatment of complex aortic pathologies involving the transverse arch with extensive involvement of the descending aorta remains a surgical challenge. Since clamshell incision provides superior exposure of the entire thoracic aorta, we evaluated the use of this technique for single-stage total arch replacement by arch vessel reconstruction. Methods The arch-first technique combined with clamshell incision was used in 38 cases of aneurysm and aortic disease in 2008 and 2009. Extensive total arch replacement was used with clamshell incision for reconstruction of arch vessels under deep hypothermic circulatory arrest. Results Overall 30-day mortality was 13%. The mean operating time was approximately 8 hours. Deep hypothermia resulted in mean CPB time exceeding 4.5 hours and mean duration of circulatory arrest was 25 minutes. The overall postoperative temporary and permanent neurologic dysfunction rates were 3% and 3% for elective and 3% and 0% for emergency surgery, respectively. All patients except the five who died in hospital were discharged without nursing care after an average post-operative hospital stay of 35 days. Conclusions The arch-first technique, combined with clamshell incision, provides expeditious replacement of the thoracic aorta with an acceptable duration of hypothermic circulatory arrest and minimizes the risk of retrograde atheroembolism by using antegrade perfusion.

Experimental study of single-electron loss by Ar{sup +} ions in rare-gas atoms

Energy Technology Data Exchange (ETDEWEB)

Reyes, P.G. [Facultad de Ciencias, UNAM, Coyoacan (Mexico); Castillo, F. [Instituto de Ciencias Nucleares, UNAM, Coyoacan (Mexico); Martinez, H. [Centro de Ciencias Fisicas, UNAM, Cuernavaca, Morelos (Mexico)]. E-mail: hm@fis.unam.mx

2001-04-28

Absolute differential and total cross sections for single-electron loss were measured for Ar{sup +} ions on rare-gas atoms in the laboratory energy range of 1.5 to 5.0 keV. The electron loss cross sections for all the targets studied are found to be in the order of magnitude between 10{sup -19} and 10{sup -22} cm{sup 2}, and show a monotonically increasing behaviour as a function of the incident energy. The behaviour of the total single-electron loss cross sections with the atomic target number, Z{sub t}, shows different dependences as the collision energy increases. In all cases the present results display experimental evidence of saturation in the single-electron loss cross section as the atomic number of the target increases. (author)

Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 1993

International Nuclear Information System (INIS)

Conrad, R.; Childs, M.; Rivera-Dirks, C.; Coriz, F.

1995-07-01

Area G, in Technical Area 54, has been the principle facility at Los Alamos National Laboratory for the storage and disposal of low-level and transuranic (TRU) radioactive wastes since 1957. The current environmental investigation consisted of ESH-19 personnel who collected soil and single-stage water samples around the perimeter of Area G to characterize possible contaminant movement through surface-water runoff. These samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241 (soil only), and cesium 137. The metals, mercury, lead, and barium, were analyzed using x-ray fluorescence

Experimental and analytical parametric study of single-crystal unimorph beams for vibration energy harvesting.

Science.gov (United States)

Karami, M Amin; Bilgen, Onur; Inman, Daniel J; Friswell, Michael I

2011-07-01

This research presents an experimental and theoretical energy harvesting characterization of beam-like, uniform cross-section, unimorph structures employing single-crystal piezoelectrics. Different piezoelectric materials, substrates, and configurations are examined to identify the best design configuration for lightweight energy harvesting devices for low-power applications. Three types of piezoelectrics (singlecrystal PMN-PZT, polycrystalline PZT-5A, and PZT-5H-type monolithic ceramics) are evaluated in a unimorph cantilevered beam configuration. The devices have been excited by harmonic base acceleration. All of the experimental characteristics have been used to validate an exact electromechanical model of the harvester. The study shows the optimum choice of substrate material for single-crystal piezoelectric energy harvesting. Comparison of energy scavengers with stainless steel substrates reveals that single-crystal harvesters produce superior power compared with polycrystalline devices. To further optimize the power harvesting, we study the relation between the thickness of the substrate and the power output for different substrate materials. The relation between power and substrate thickness profoundly varies among different substrate materials. The variation is understood by examining the change of mechanical transmissibility and the variations of the coupling figure of merit of the harvesters with thickness ratio. The investigation identifies the optimal thickness of the substrate for different substrate materials. The study also shows that the densities of the substrates and their mechanical damping coefficients have significant effects on the power output.

Experimental Results for Direction of Arrival Estimation with a Single Acoustic Vector Sensor in Shallow Water

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Alper Bereketli

2015-01-01

Full Text Available We study the performances of several computationally efficient and simple techniques for estimating direction of arrival (DOA of an underwater acoustic source using a single acoustic vector sensor (AVS in shallow water. Underwater AVS is a compact device, which consists of one hydrophone and three accelerometers in a packaged form, measuring scalar pressure and three-dimensional acceleration simultaneously at a single position. A very controlled experimental setup is prepared to test how well-known techniques, namely, arctan-based, intensity-based, time domain beamforming, and frequency domain beamforming methods, perform in estimating DOA of a source in different circumstances. Experimental results reveal that for almost all cases beamforming techniques perform best. Moreover, arctan-based method, which is the simplest of all, provides satisfactory results for practical purposes.

A dual-stage sodium thermal electrochemical converter (Na-TEC)

Science.gov (United States)

Limia, Alexander; Ha, Jong Min; Kottke, Peter; Gunawan, Andrey; Fedorov, Andrei G.; Lee, Seung Woo; Yee, Shannon K.

2017-12-01

The sodium thermal electrochemical converter (Na-TEC) is a heat engine that generates electricity through the isothermal expansion of sodium ions. The Na-TEC is a closed system that can theoretically achieve conversion efficiencies above 45% when operating between thermal reservoirs at 1150 K and 550 K. However, thermal designs have confined previous single-stage devices to thermal efficiencies below 20%. To mitigate some of these limitations, we consider dividing the isothermal expansion into two stages; one at the evaporator temperature (1150 K) and another at an intermediate temperature (650 K-1050 K). This dual-stage Na-TEC takes advantage of regeneration and reheating, and could be amenable to better thermal management. Herein, we demonstrate how the dual-stage device can improve the efficiency by up to 8% points over the best performing single-stage device. We also establish an application regime map for the single- and dual-stage Na-TEC in terms of the power density and the total thermal parasitic loss. Generally, a single-stage Na-TEC should be used for applications requiring high power densities, whereas a dual-stage Na-TEC should be used for applications requiring high efficiency.

Unconditional and Conditional QTL Mapping for Tiller Numbers at Various Stages with Single Segment Substitution Lines in Rice (Oryza sativa L.)

Institute of Scientific and Technical Information of China (English)

ZHAO Fang-ming; LIU Gui-fu; ZHU Hai-tao; DING Xiao-hua; ZENG Rui-zhen; ZHANG Ze-min; LI Wen-tao; ZHANG Gui-quan

2008-01-01

Tiller is one of the most important agronomic traits which influences quantity and quality of effective panicles and finally influences yield in rice.It is important to understand "static" and "dynamic" information of the QTLs for tillers in rice.This work was the first time to simultaneously map unconditional and conditional QTLs for tiller numbers at various stages by using single segment substitution lines in rice.Fourteen QTLs for tiller number,distributing on the corresponding substitution segments of chromosomes 1,2,3,4,6,7 and 8 were detected.Both the number and the effect of the QTLs for tiller number were various at different stages,from 6 to 9 in the number and from 1.49 to 3.49 in the effect,respectively. Tiller number QTLs expressed in a time order,mainly detected at three stages of 0-7d,14-21d and 35-42d after transplanting with 6 positive,9 random and 6 negative expressing QTLs,respectively.Each of the QTLs expressed one time at least during the whole duration of rice.The tiller number at a specific stage was determined by sum of QTL effects estimated by the unconditional method,while the increasing or decreasing number in a given time interval was controlled by the total of QTL effects estimated by the conditional method.These results demonstrated that it is highly effective and accurate for mapping of the QTLs by using single segment substitution lines and the conditional analysis methodology.

Satisfactory knee function after single-stage posterolateral corner reconstruction in the multi-ligament injured/dislocated knee using the anatomic single-graft technique.

Science.gov (United States)

Sanders, Thomas L; Johnson, Nick R; Pareek, Ayoosh; Krych, Aaron J; Marx, Robert G; Stuart, Michael J; Levy, Bruce A

2018-04-01

Increasing importance has been placed on the posterolateral corner (PLC) in maintaining varus and rotational stability of the knee. The goal of this study was to evaluate knee function and clinical stability following a single-graft PLC reconstruction technique and identify factors associated with poor knee function. This study identified patients with a multi-ligament knee injury between 2006 and 2013. Patients who received a single-graft fibular collateral ligament and PLC reconstruction with a single-stage surgery during the study period and had a minimum follow-up of 2 years after surgery were included. Functional outcomes were assessed using Lysholm and IKDC scores. Varus and rotational knee laxity and range of motion were assessed using physical examination. The final study cohort included 61 patients who underwent PLC reconstruction using a single-graft technique. The mean IKDC score was 74.1 (± 22.3) and the mean Lysholm score was 80.3 (± 21.8) at mean follow-up of 3.8 years (range 2-9 years). Mean range of motion at final follow-up measured from 0° to 126° [range flexion: 95-145, range extension: 0-5]. Fifty-eight patients (95%) had grade 0 varus laxity in full knee extension, and 54 patients (88.5%) had grade 0 varus laxity at 30° of knee flexion. Female gender was associated with a lower postoperative IKDC score (p = 0.04). Surgical treatment of the PLC using a single-graft technique can result in satisfactory knee function and stable physical examination findings at minimum 2 years after surgery. Female gender was predictive of poor knee function after PLC reconstruction. Surgical treatment of PLC injuries should be individualized based on the timing of surgery, specific injured knee structures, and physical examination findings. This study helps validate the use of a single-graft technique for PLC reconstruction and can be used to help counsel patients about expected knee function after surgical treatment of PLC injuries. Level of evidence

Cerebral staging of lung cancer: is one single contrast-enhanced T1-weighted three-dimensional gradient-echo sequence sufficient?

Energy Technology Data Exchange (ETDEWEB)

Ohana, Mickael; Jeung, Mi-Young; Roy, Catherine [Nouvel Hopital Civil-Hopitaux Universitaires de Strasbourg, Service de Radiologie B/Radiology Department, Strasbourg (France); Bazille, Gauthier [Clinique Saint Anne-Groupe Radiologique MIM, Strasbourg (France)

2014-08-15

Gadolinium-enhanced magnetic resonance imaging (MRI) is the gold standard for cerebral staging in thoracic oncology. We hypothesize that a minimalist examination, consisting of a single contrast-enhanced T1-weighted three-dimensional gradient-echo sequence (CE 3D-GRE), would be sufficient for the cerebral staging of nonsymptomatic lung cancer patients. Seventy nonsymptomatic patients (50 % men; 62 years ± 10.2) referred for cerebral staging of a lung cancer were retrospectively included. All underwent a standard 3 T MRI examination with T1, FLAIR, T2* GRE, diffusion, and CE 3D-GRE sequences, for a total examination time of 20 min. The sole CE 3D-GRE (acquisition time: 6 min) was extracted and blindly interpreted by two radiologists in search of brain metastases. Hemorrhagic features of potential lesions and relevant incidental findings were also noted. Discrepant cases were reviewed by a third reader. The full MRI examination and follow-up studies were used as a reference to calculate sensitivity and specificity of the sole CE 3D-GRE. Thirty-eight point six percent (27 out of 70) of the patients had brain metastases. Performances and reader's agreement with the sole CE 3D-GRE sequence were excellent for the diagnosis of brain metastases (sensitivity = 96.3 %, specificity = 100 %, κ = 0.91) and incidental findings (sensitivity = 85.7 %, specificity = 100 %, κ = 0.62) but insufficient for the identification of hemorrhages within the metastases (sensitivity = 33.3 %, specificity = 85.7 %, κ = 0.47). In the specific case of lung cancer, cerebral staging in nonsymptomatic patients can be efficiently achieved with a minimalistic protocol consisting of a single CE 3D-GRE sequence, completed if positive with a T2* sequence for hemorrhagic assessment, thus halving appointment delays. (orig.)

Two-Stage Centrifugal Fan

Science.gov (United States)

Converse, David

2011-01-01

Fan designs are often constrained by envelope, rotational speed, weight, and power. Aerodynamic performance and motor electrical performance are heavily influenced by rotational speed. The fan used in this work is at a practical limit for rotational speed due to motor performance characteristics, and there is no more space available in the packaging for a larger fan. The pressure rise requirements keep growing. The way to ordinarily accommodate a higher DP is to spin faster or grow the fan rotor diameter. The invention is to put two radially oriented stages on a single disk. Flow enters the first stage from the center; energy is imparted to the flow in the first stage blades, the flow is redirected some amount opposite to the direction of rotation in the fixed stators, and more energy is imparted to the flow in the second- stage blades. Without increasing either rotational speed or disk diameter, it is believed that as much as 50 percent more DP can be achieved with this design than with an ordinary, single-stage centrifugal design. This invention is useful primarily for fans having relatively low flow rates with relatively high pressure rise requirements.

Performance analysis of the single-stage absorption heat transformer using a new working pair composed of ionic liquid and water

International Nuclear Information System (INIS)

Zhang Xiaodong; Hu Dapeng

2012-01-01

The performance simulation of a single-stage absorption heat transformer using a new working pair composed of ionic liquids, 1-ethyl-3-methylimidazolium dimethylphosphate, and water (H 2 O + [EMIM][DMP]), was performed based on the thermodynamic properties of the new working pair and on the mass and energy balance for each component of the system. In order to evaluate the new working pair, the simulation results were compared with those of aqueous solution of lithium bromide (H 2 O + LiBr), Trifluoroethanol (TFE) + tetraethylenglycol dimethylether (E181). The results indicate that when generation, evaporation, condensing and absorption temperatures are 90 °C, 90 °C, 35 °C and 130 °C, the coefficients of performance of the single-stage absorption heat transformer using H 2 O + LiBr, H 2 O + [EMIM][DMP] and TFE + E181 as working pairs will reach 0.494, 0.481 and 0.458 respectively. And the corresponding exergy efficiency will reach 0.64, 0.62 and 0.59, respectively. Meanwhile the available heat outputs for per unit mass of refrigerant are 2466 kJ/kg, 2344 kJ/kg and 311 kJ/kg, respectively. The above excellent cycle performance together with the advantages of negligible vapor pressure, no crystallization and more weak corrosion tendency to iron-steel materials may make the new working pair better suited for the industrial absorption heat transformer. - Highlights: ► The cycle performance of the single-stage absorption heat transformer was simulated. ► Water and 1-ethyl-3-methylimidazolium dimethylphosphate was used as new working pair. ► Water and 1-ethyl-3-methylimidazolium dimethylphosphate are entirely miscible. ► The COP and exergy efficiency for this new working pairs were 0.481 and 0.62. ► The new working pairs has potential application to absorption heat transformer.

A New Three-Dimensional High-Accuracy Automatic Alignment System For Single-Mode Fibers

Science.gov (United States)

Yun-jiang, Rao; Shang-lian, Huang; Ping, Li; Yu-mei, Wen; Jun, Tang

1990-02-01

In order to achieve the low-loss splices of single-mode fibers, a new three-dimension high-accuracy automatic alignment system for single -mode fibers has been developed, which includes a new-type three-dimension high-resolution microdisplacement servo stage driven by piezoelectric elements, a new high-accuracy measurement system for the misalignment error of the fiber core-axis, and a special single chip microcomputer processing system. The experimental results show that alignment accuracy of ±0.1 pin with a movable stroke of -±20μm has been obtained. This new system has more advantages than that reported.

Multi-staging for extraction of cesium from nitric acid by a single liquid-liquid countercurrent centrifugal extractor with Taylor vortices

International Nuclear Information System (INIS)

Nakase, Masahiko; Kinuhata, Hiroshi; Takeshita, Kenji

2013-01-01

Fission products that emit considerable decay heat and radioactivity, such as 137 Cs, have a large impact on waste management. Small and high-performance extractor is desirable for separating such nuclei. In this study, we implemented the continuous extraction of Cs from nitric acid in a single liquid-liquid countercurrent centrifugal extractor with Taylor Vortices by calix arene-bis(t-octylbenzo-crown-6)(BOBCalixC6) as an extractant with trioctylamine(TOA) as a suppressant and with 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) as a phase modifier. Because of slow extraction kinetics of this process, extraction with multiple theoretical stages by just replacing conventional extractors into the single centrifugal extractor is difficult. Hence, we improved the dispersion of organic phase by an inner rotor made of lipophilic epoxy resin and elevating the solution temperature to lower the viscosity. Higher temperature was not appropriate from the aspect of chemical equilibrium in this process, but extraction with multiple theoretical stages was found to be possible. (author)

Two-Stage n-PSK Partitioning Carrier Phase Recovery Scheme for Circular mQAM Coherent Optical Systems

Directory of Open Access Journals (Sweden)

Jaime Rodrigo Navarro

2016-06-01

Full Text Available A novel two-stage n-PSK partitioning carrier phase recovery (CPR scheme for circular multilevel quadrature amplitude modulation (C-mQAM constellations is presented. The first stage of the algorithm provides an initial rough estimation of the received constellation, which is utilized in the second stage for CPR. The performance of the proposed algorithm is studied through extensive simulations at the forward error correction bit error rate targets of 3.8 × 10−3 and 1 × 10−2 and is compared with different CPR algorithms. A significant improvement in the combined linewidth symbol duration product (ΔνTs tolerance is achieved compared to the single-stage n-PSK partitioning scheme. Superior performance in the ΔνTs tolerance compared to the blind phase search algorithm is also reported. The relative improvements with respect to other CPR schemes are also validated experimentally for a 28-Gbaud C-16QAM back-to-back transmission system. The computational complexity of the proposed CPR scheme is studied, and reduction factors of 24.5 | 30.1 and 59.1 | 63.3 are achieved for C-16QAM and C-64QAM, respectively, compared to single-stage BPS in the form of multipliers | adders.

Repetitive, small-bore two-stage light gas gun

International Nuclear Information System (INIS)

Combs, S.K.; Foust, C.R.; Fehling, D.T.; Gouge, M.J.; Milora, S.L.

1991-01-01

A repetitive two-stage light gas gun for high-speed pellet injection has been developed at Oak Ridge National Laboratory. In general, applications of the two-stage light gas gun have been limited to only single shots, with a finite time (at least minutes) needed for recovery and preparation for the next shot. The new device overcomes problems associated with repetitive operation, including rapidly evacuating the propellant gases, reloading the gun breech with a new projectile, returning the piston to its initial position, and refilling the first- and second-stage gas volumes to the appropriate pressure levels. In addition, some components are subjected to and must survive severe operating conditions, which include rapid cycling to high pressures and temperatures (up to thousands of bars and thousands of kelvins) and significant mechanical shocks. Small plastic projectiles (4-mm nominal size) and helium gas have been used in the prototype device, which was equipped with a 1-m-long pump tube and a 1-m-long gun barrel, to demonstrate repetitive operation (up to 1 Hz) at relatively high pellet velocities (up to 3000 m/s). The equipment is described, and experimental results are presented. 124 refs., 6 figs., 5 tabs

Single-Staged Compared With Multi-Staged PCI in Multivessel NSTEMI Patients: The SMILE Trial.

Science.gov (United States)

Sardella, Gennaro; Lucisano, Luigi; Garbo, Roberto; Pennacchi, Mauro; Cavallo, Erika; Stio, Rocco Edoardo; Calcagno, Simone; Ugo, Fabrizio; Boccuzzi, Giacomo; Fedele, Francesco; Mancone, Massimo

2016-01-26

A lack of clarity exists about the role of complete coronary revascularization in patients presenting with non-ST-segment elevation myocardial infarction. The aim of our study was to compare long-term outcomes in terms of major adverse cardiovascular and cerebrovascular events of 2 different complete coronary revascularization strategies in patients with non-ST-segment elevation myocardial infarction and multivessel coronary artery disease: 1-stage percutaneous coronary intervention (1S-PCI) during the index procedure versus multistage percutaneous coronary intervention (MS-PCI) complete coronary revascularization during the index hospitalization. In the SMILE (Impact of Different Treatment in Multivessel Non ST Elevation Myocardial Infarction Patients: One Stage Versus Multistaged Percutaneous Coronary Intervention) trial, 584 patients were randomly assigned in a 1:1 manner to 1S-PCI or MS-PCI. The primary study endpoint was the incidence of major adverse cardiovascular and cerebrovascular events, which were defined as cardiac death, death, reinfarction, rehospitalization for unstable angina, repeat coronary revascularization (target vessel revascularization), and stroke at 1 year. The occurrence of the primary endpoint was significantly lower in the 1-stage group (1S-PCI: n = 36 [13.63%] vs. MS-PCI: n = 61 [23.19%]; hazard ratio [HR]: 0.549 [95% confidence interval (CI): 0.363 to 0.828]; p = 0.004). The 1-year rate of target vessel revascularization was significantly higher in the MS-PCI group (1S-PCI: n = 22 [8.33%] vs. MS-PCI: n = 40 [15.20%]; HR: 0.522 [95% CI: 0.310 to 0.878]; p = 0.01; p log-rank = 0.013). When the analyses were limited to cardiac death (1S-PCI: n = 9 [3.41%] vs. MS-PCI: n = 14 [5.32%]; HR: 0.624 [95% CI: 0.270 to 1.441]; p = 0.27) and myocardial infarction (1S-PCI: n = 7 [2.65%] vs. MS-PCI: n = 10 [3.80%]; HR: 0.678 [95% CI: 0.156 to 2.657]; p = 0.46), no significant differences were observed between groups. In multivessel

Experimental study of a staged combustion system for stationary gas turbine applications

Science.gov (United States)

Lamont, Warren G.

Two optically accessible experimental test rigs were designed and constructed to investigate a staged or distributed combustion system for stationary gas turbine applications. The test rigs were fuelled with natural gas and featured two combustion zones: the main combustion zone (MCZ) and the secondary combustion zone (SCZ). The MCZ is a swirl stabilized dump combustor and the SCZ, which is axially downstream from the MCZ, is formed by a transverse jet injecting a premixed fuel/air mixture into the vitiated stream. After installing and commissioning the test rig, an emission survey was conducted to investigate the SCZ conditions, equivalence ratio and momentum ratio, that produce low NOx emissions and give a higher temperature rise before a simulated high pressure turbine than firing only the MCZ. The emission survey found several operating conditions that show the benefit of combustion staging. These beneficial conditions had an SCZ equivalence ratio between 0.41 and 1.12. The data from the emission survey was then used to create an artificial neural network (ANN). The ANN used a multi-layer feed-forward network architecture and was trained with experimental data using the backpropagation training algorithm. The ANN was then used to create performance maps and optimum operational regions were sought. Lastly, optical diagnostics were used to obtain information on the nature of the SCZ reactive jet. The diagnostics included high speed CH* chemiluminescence, OH planar laser induced fluorescence (PLIF) and dual-pump coherent anti-Stokes Raman scattering (CARS). The chemiluminescence and PLIF were used to qualitatively determine the size and shape of the transverse jet reaction zone. Dual-pump CARS was used to quantitatively determine the temperature and H2/N2 concentration ratio profile at the mid-plane of the transverse jet. Dual-pump CARS data was collected for four operating conditions but only one is presented in this dissertation. For the condition presented, the

Experimental Verification of the Transient Model in an Enrichment Circuit

International Nuclear Information System (INIS)

Fernandino, Maria; Brasnarof, Daniel; Delmastro, Dario

2003-01-01

In the present work an experimental closed loop representing a single stage of an uranium gaseous diffusion enrichment cascade is described, loop that is used to experimentally validate an analytical model that describes the dynamics inside such a loop.The conditions established inside the experimental loop after a few working hours were reproduced by the analytical model, leaving the slower thermal phenomena taking place for future studies.Two kinds of perturbations were experimentally introduced: a change in the range of operation of one of the compressors and the addition of mass into the loop.Numerical and experimental results are compared and presented in this work. The analytical model proposed was verified against these two changes, with very good agreement in the time response and measured values.This analytical model allows us to determine the characteristic time response of the system

Aeration Strategies To Mitigate Nitrous Oxide Emissions from Single-Stage Nitritation/Anammox Reactors

DEFF Research Database (Denmark)

Domingo Felez, Carlos; Mutlu, A. Gizem; Jensen, Marlene Mark

2014-01-01

Autotrophic nitrogen removal is regarded as a resource efficient process to manage nitrogen-rich residual streams. However, nitrous oxide emissions of these processes are poorly documented and strategies to mitigate emissions unknown. In this study, two sequencing batch reactors performing single...... was noted when the duration of aeration was increased while decreasing air flow rate (10.9 +/- 3.2% Delta N2O/Delta TN). The extant ammonium oxidation activity (mgNH(4)(+)-N/gVSS.min) positively correlated with the specific N2O production rate (mgN(2)O-N/gVSS.min) of the systems. Operating under conditions......-stage nitritation/anammox were operated under different aeration strategies, gradually adjusted over six months. At constant but limiting oxygen loading, synthetic reject water was fed (0.75g-N/L.d) and high nitrogen removal efficiencies (83 +/- 5 and 88 +/- 2%) obtained. Dynamics of liquid phase nitrous (N2O...

Experimental characterization of diesel ignition and lift-off length using a single-hole ECN injector

International Nuclear Information System (INIS)

Benajes, Jesús; Payri, Raúl; Bardi, Michele; Martí-Aldaraví, Pedro

2013-01-01

In this work, lift-off length and ignition delay have been measured via chemiluminescence techniques in a wide range of conditions for a single-hole injector from the Engine Combustion Network (ECN) dataset and using a single component fuel (n-dodecane). In addition, Schlieren technique was used to characterize the ignition event using a new developed post-processing methodology capable of characterizing the “disappearance” phenomenon linked to the start of cool flames. Experiments have been carried out in a novel constant-pressure flow facility able of reproducing engine-like thermodynamic conditions. Results show that oxygen concentration seems to have a negligible impact on the start of cool flames. Empirical correlations have been obtained for the three measured parameters and they manifest similar trends of other previously published correlations for lift-off length and second stage ignition. These correlations also underline that the effect of oxygen concentration and ambient density is caught differently by chemiluminescence and Schlieren techniques, even though the absolute value of the measurements remains close. -- Highlights: • Ignition delay and LOL of an ECN injector are measured using the ECN standard diagnostics. • A novel processing is developed for Schlieren images to determine first and second stage ignition. • A sweep of injection pressure, density, temperature and oxygen concentration is performed. • A statistical analysis is done to provide an analytical description of the results

Single-staged resections and 3D reconstructions of the nasion, glabella, medial orbital wall, and frontal sinus and bone: Long-term outcome and review of the literature.

Science.gov (United States)

Ciporen, Jeremy; Lucke-Wold, Brandon P; Mendez, Gustavo; Chen, Anton; Banerjee, Amit; Akins, Paul T; Balough, Ben J

2016-01-01

Aesthetic facial appearance following neurosurgical ablation of frontal fossa tumors is a primary concern for patients and neurosurgeons alike. Craniofacial reconstruction procedures have drastically evolved since the development of three-dimensional computed tomography imaging and computer-assisted programming. Traditionally, two-stage approaches for resection and reconstruction were used; however, these two-stage approaches have many complications including cerebrospinal fluid leaks, necrosis, and pneumocephalus. We present two successful cases of single-stage osteoma resection and craniofacial reconstruction in a 26-year-old female and 65-year-old male. The biopolymer implants were preselected and contoured based on imaging prior to surgery. The ideal selection of appropriate flaps for reconstruction was imperative. The flaps were well vascularized and included a pedicle for easy translocation. Using a titanium mesh biopolymer implant for reconstruction in conjunction with a forehead flap proved advantageous, and the benefits of single-stage approaches were apparent. The patients recovered quickly after the surgery with complete resection of the osteoma and good aesthetic appearance. The flap adhered to the biopolymer implant, and the cosmetic appearance years after surgery remained decent. The gap between the bone and implant was less than 2 mm. The patients are highly satisfied with the symmetrical appearance of the reconstruction. Advances in technology are allowing neurosurgeons unprecedented opportunities to design complex yet feasible single-stage craniofacial reconstructions that improve a patient's quality of life by enhancing facial contours, aesthetics, and symmetry.

Detection of Brucella melitensis and Brucella abortus strains using a single-stage PCR method

Directory of Open Access Journals (Sweden)

Alamian, S.

2015-04-01

Full Text Available Brucella melitensis and Brucella abortus are of the most important causes of brucellosis, an infectious disease which is transmitted either directly or indirectly including consuming unpasteurized dairy products. Both strains are considered endemic in Iran. Common diagnostic methods such as bacteriologic cultures are difficult and time consuming regarding the bacteria. The aim of this study was to suggest a single-stage PCR method using a pair of primers to detect both B. melitensis and B. abortus. The primers were named UF1 and UR1 and the results showed that the final size of PCR products were 84 bp and 99 bp for B. melitensis and B. abortus, respectively. Therefore the method could be useful for rapid detection of B. melitensis and B. abortus simultaneously.

An experimental study on improvement of Savonius rotor performance

Directory of Open Access Journals (Sweden)

N.H. Mahmoud

2012-03-01

In this work different geometries of Savonius wind turbine are experimentally studied in order to determine the most effective operation parameters. It was found that, the two blades rotor is more efficient than three and four ones. The rotor with end plates gives higher efficiency than those of without end plates. Double stage rotors have higher performance compared to single stage rotors. The rotors without overlap ratio (β are better in operation than those with overlap. The results show also that the power coefficient increases with rising the aspect ratio (α. The conclusions from the measurements of the static torque for each rotor at different wind speeds verify the above summarized results of this work.

SU-E-T-480: Radiobiological Dose Comparison of Single Fraction SRS, Multi-Fraction SRT and Multi-Stage SRS of Large Target Volumes Using the Linear-Quadratic Formula

International Nuclear Information System (INIS)

Ding, C; Hrycushko, B; Jiang, S; Meyer, J; Timmerman, R

2014-01-01

Purpose: To compare the radiobiological effect on large tumors and surrounding normal tissues from single fraction SRS, multi-fractionated SRT, and multi-staged SRS treatment. Methods: An anthropomorphic head phantom with a centrally located large volume target (18.2 cm 3 ) was scanned using a 16 slice large bore CT simulator. Scans were imported to the Multiplan treatment planning system where a total prescription dose of 20Gy was used for a single, three staged and three fractionated treatment. Cyber Knife treatment plans were inversely optimized for the target volume to achieve at least 95% coverage of the prescription dose. For the multistage plan, the target was segmented into three subtargets having similar volume and shape. Staged plans for individual subtargets were generated based on a planning technique where the beam MUs of the original plan on the total target volume are changed by weighting the MUs based on projected beam lengths within each subtarget. Dose matrices for each plan were export in DICOM format and used to calculate equivalent dose distributions in 2Gy fractions using an alpha beta ratio of 10 for the target and 3 for normal tissue. Results: Singe fraction SRS, multi-stage plan and multi-fractionated SRT plans had an average 2Gy dose equivalent to the target of 62.89Gy, 37.91Gy and 33.68Gy, respectively. The normal tissue within 12Gy physical dose region had an average 2Gy dose equivalent of 29.55Gy, 16.08Gy and 13.93Gy, respectively. Conclusion: The single fraction SRS plan had the largest predicted biological effect for the target and the surrounding normal tissue. The multi-stage treatment provided for a more potent biologically effect on target compared to the multi-fraction SRT treatments with less biological normal tissue than single-fraction SRS treatment

The Pathological Changes of Stomach in Experimental Rats following Single Irradiation of Supervoltage

International Nuclear Information System (INIS)

Choi, Myung Sun; Suh, Won Hyuck

1984-01-01

The pathological changes of stomach of the rat following 1,000 rad and 1,800 rad single exposure by Cobalt-60 has been made with 50 experimental rats. The dose of 1,000 rad and 6,000 rad in 6 weeks. Following single exposure, the groups of rat were terminated in 1, 2, 4, 8, 12 weeks intervals and the stomach were fixed to formalin solution immediately after dissection. The pathological changes were as follows: 1. Following 1,000 rad single exposure, the stomach show only mild to moderate submucosal edema in 4, 8, 12 weeks group. 1 and 2 weeks group show no changes. 2. Following 1,800 rad single exposure, 32%(8/25) of rats were dead by radiation effect and all other groups of stomach revealed variable pathological changes such as submucosal edema, squamous dysplasia, squamous papilloma as well as squamous cell carcinoma. 3. Optimal tolerance dose to the stomach was 4,500-5,000 rad when irradiation given by supervoltage. The entire stomach was included within the irradiation field, the dose to the stomach should not exceed 6,000 rad. 4. In conclusion, the radiation injury to the stomach were more direct radiation effects to the gastric mucosa rather than secondary changes of radiation injured vessels

A Cost-Effective Power Ramp-Rate Control Strategy for Single-Phase Two-Stage Grid-Connected Photovoltaic Systems

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

2016-01-01

In the case of a wide-scale adoption of grid-connected Photovoltaic (PV) systems, more fluctuated power will be injected into the grid due to the intermittency of solar PV energy. A sudden change in the PV power can potentially induce grid voltage fluctuations, and thus challenge the stability......-point. Experiments conducted on a 3-kW single-phase two-stage grid-connected PV system have verified that the proposed solution can accomplish fast dynamics, high accuracy, and high robustness in the power ramp-rate control for PV systems....

An approach to eliminate stepped features in multistage incremental sheet forming process: Experimental and FEA analysis

Energy Technology Data Exchange (ETDEWEB)

Nirala, Harish Kumar; Jain, Prashant K.; Tandon, Puneet [PDPM Indian Institute of Information Technology, Design and Manufacturing Jabalpur Jabalpur-482005, Madhya Pradesh (India); Roy, J. J.; Samal, M. K. [Bhabha Atomic Research Centre, Mumbai (India)

2017-02-15

Incremental sheet forming (ISF) is a recently developed manufacturing technique. In ISF, forming is done by applying deformation force through the motion of Numerically controlled (NC) single point forming tool on the clamped sheet metal blank. Single Point Incremental sheet forming (SPISF) is also known as a die-less forming process because no die is required to fabricate any component by using this process. Now a day it is widely accepted for rapid manufacturing of sheet metal components. The formability of SPISF process improves by adding some intermediate stages into it, which is known as Multi-stage SPISF (MSPISF) process. However during forming in MSPISF process because of intermediate stages stepped features are generated. This paper investigates the generation of stepped features with simulation and experimental results. An effective MSPISF strategy is proposed to remove or eliminate this generated undesirable stepped features.

An experimental and numerical study of developed single phase axial turbulent flow in a smooth rod bundle

International Nuclear Information System (INIS)

Hooper, J.D.

1977-01-01

A combined experimental and numerical model of a turbulent single phase coolant, flowing axially along the fuel pins of a nuclear reactor, was developed. The experimental rig represented two interconnected subchannels of a square array at a pitch/diameter ratio of 1.193. Air was the working fluid, and measurements were made of the mean radial velocity profiles, wall shear stress variation, turbulence velocity spectra and intensities. The numerically predicted wall shear distribution and mean velocity profiles, obtained using an empirical two-dimensional mixing length and eddy diffusivity concept to represent fluid turbulence, showed good agreement with the experimental results. (Author)

Single-stage anaerobic treatment of non-settled slaughterhouse waste water using a fixed-bed reactor. Einstufige anaerobe Behandlung von nicht abgesetztem Schlachthofabwasser in einem Festbettreaktor

Energy Technology Data Exchange (ETDEWEB)

Tritt, W.P. (Bundesforschungsanstalt fuer Landwirtschaft, Braunschweig (Germany). Inst. fuer Technologie); Meyer-Jacob, H.

1992-01-01

Along with the determination of the degree of acidification during an intermediate storage of the crude slaughterhouse wastewater and deriving a single-stage or two-stage process, the start-up behaviour of the fixed-bed reactor, its degradation rates in upflow and downflow operation is descirbed. With regard to a subsequent biological denitrification the COD/N ratio of anaerobically treated wastewater is given. (orig.).

Impact of interstitial iron on the study of meta-stable B-O defects in Czochralski silicon: Further evidence of a single defect

Science.gov (United States)

Kim, Moonyong; Chen, Daniel; Abbott, Malcolm; Nampalli, Nitin; Wenham, Stuart; Stefani, Bruno; Hallam, Brett

2018-04-01

We explore the influence of interstitial iron (Fei) on lifetime spectroscopy of boron-oxygen (B-O) related degradation in p-type Czochralski silicon. Theoretical and experimental evidence presented in this study indicate that iron-boron pair (Fe-B) related reactions could have influenced several key experimental results used to derive theories on the fundamental properties of the B-O defect. Firstly, the presence of Fei can account for higher apparent capture cross-section ratios (k) of approximately 100 observed in previous studies during early stages of B-O related degradation. Secondly, the association of Fe-B pairs can explain the initial stage of a two-stage recovery of carrier lifetime with dark annealing after partial degradation. Thirdly, Fei can result in high apparent k values after the permanent deactivation of B-O defects. Subsequently, we show that a single k value can describe the recombination properties associated with B-O defects throughout degradation, that the recovery during dark annealing occurs with a single-stage, and both the fast- and slow-stage B-O related degradation can be permanently deactivated during illuminated annealing. Accounting for the recombination activity of Fei provides further evidence that the B-O defect is a single defect, rather than two separate defects normally attributed to fast-forming recombination centers and slow-forming recombination centers. Implications of this finding for the nature of the B-O defect are also discussed.

Simulation and Experimental Characterization of Microscopically Accessible Hydrodynamic Microvortices

Directory of Open Access Journals (Sweden)

Deirdre R. Meldrum

2012-06-01

Full Text Available Single-cell studies of phenotypic heterogeneity reveal more information about pathogenic processes than conventional bulk-cell analysis methods. By enabling high-resolution structural and functional imaging, a single-cell three-dimensional (3D imaging system can be used to study basic biological processes and to diagnose diseases such as cancer at an early stage. One mechanism that such systems apply to accomplish 3D imaging is rotation of a single cell about a fixed axis. However, many cell rotation mechanisms require intricate and tedious microfabrication, or fail to provide a suitable environment for living cells. To address these and related challenges, we applied numerical simulation methods to design new microfluidic chambers capable of generating fluidic microvortices to rotate suspended cells. We then compared several microfluidic chip designs experimentally in terms of: (1 their ability to rotate biological cells in a stable and precise manner; and (2 their suitability, from a geometric standpoint, for microscopic cell imaging. We selected a design that incorporates a trapezoidal side chamber connected to a main flow channel because it provided well-controlled circulation and met imaging requirements. Micro particle-image velocimetry (micro-PIV was used to provide a detailed characterization of flows in the new design. Simulated and experimental results demonstrate that a trapezoidal side chamber represents a viable option for accomplishing controlled single cell rotation. Further, agreement between experimental and simulated results confirms that numerical simulation is an effective method for chamber design.

Multi Stage Strategies for Single Point Incremental Forming of a Cup

DEFF Research Database (Denmark)

Skjødt, Martin; Bay, Niels; Endelt, Benny

2008-01-01

A five stage forming strategy for forming of a circular cylindrical cup with a height/radius ratio of one is presented. Geometrical relations are discussed and theoretical strains are calculated. The influence of forming direction (upwards or downwards) is investigated for the second stage...... comparing explicit FE analysis with experiments. Good agreement is found between calculated and measured thickness distribution, overall geometry and strains. Using the proposed multi stage strategy it is shown possible to produce a cup with a height close to the radius and side parallel to the symmetry...

Behavior of single lap composite bolted joint under traction loading: Experimental investigation

Science.gov (United States)

Awadhani, L. V.; Bewoor, Anand

2018-04-01

Composite bolted joints are preferred connection in the composite structures to facilitate the dismantling for the replacements/ maintenance work. The joint behavior under tractive forces has been studied in order to understand the safety of the structure designed. The main objective of this paper is to investigate the behavior of single-lap joints in carbon fiber reinforced epoxy composites under traction loading conditions. The experiments were designed to identify the effect of bolt diameter, stacking sequence and loading rate on the properties of the joint. The experimental results show that the parameters influence the joint performance significantly.

EXPERIMENTAL DETERMINATION OF LONGITUDINAL COMPONENT OF MAGNETIC FLUX IN FERROMAGNETIC WIRE OF SINGLE-CORE POWER CABLE ARMOUR

Directory of Open Access Journals (Sweden)

I.A. Kostiukov

2014-12-01

Full Text Available A problem of determination of effective longitudinal magnetic permeability of single core power cable armour is defined. A technique for experimental determination of longitudinal component of magnetic flux in armour spiral ferromagnetic wire is proposed.

Optimal dynamic performance for high-precision actuators/stages

International Nuclear Information System (INIS)

Preissner, C.; Lee, S.-H.; Royston, T. J.; Shu, D.

2002-01-01

System dynamic performance of actuator/stage groups, such as those found in optical instrument positioning systems and other high-precision applications, is dependent upon both individual component behavior and the system configuration. Experimental modal analysis techniques were implemented to determine the six degree of freedom stiffnesses and damping for individual actuator components. These experimental data were then used in a multibody dynamic computer model to investigate the effect of stage group configuration. Running the computer model through the possible stage configurations and observing the predicted vibratory response determined the optimal stage group configuration. Configuration optimization can be performed for any group of stages, provided there is stiffness and damping data available for the constituent pieces

Experiments for Multi-Stage Processes

DEFF Research Database (Denmark)

Tyssedal, John; Kulahci, Murat

2015-01-01

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

Modeling single ventricle physiology: review of engineering tools to study first stage palliation of hypoplastic left heart syndrome.

Science.gov (United States)

Biglino, Giovanni; Giardini, Alessandro; Hsia, Tain-Yen; Figliola, Richard; Taylor, Andrew M; Schievano, Silvia

2013-10-30

First stage palliation of hypoplastic left heart syndrome, i.e., the Norwood operation, results in a complex physiological arrangement, involving different shunting options (modified Blalock-Taussig, RV-PA conduit, central shunt from the ascending aorta) and enlargement of the hypoplastic ascending aorta. Engineering techniques, both computational and experimental, can aid in the understanding of the Norwood physiology and their correct implementation can potentially lead to refinement of the decision-making process, by means of patient-specific simulations. This paper presents some of the available tools that can corroborate clinical evidence by providing detailed insight into the fluid dynamics of the Norwood circulation as well as alternative surgical scenarios (i.e., virtual surgery). Patient-specific anatomies can be manufactured by means of rapid prototyping and such models can be inserted in experimental set-ups (mock circulatory loops) that can provide a valuable source of validation data as well as hydrodynamic information. Such models can be tuned to respond to differing the patient physiologies. Experimental set-ups can also be compatible with visualization techniques, like particle image velocimetry and cardiovascular magnetic resonance, further adding to the knowledge of the local fluid dynamics. Multi-scale computational models include detailed three-dimensional (3D) anatomical information coupled to a lumped parameter network representing the remainder of the circulation. These models output both overall hemodynamic parameters while also enabling to investigate the local fluid dynamics of the aortic arch or the shunt. As an alternative, pure lumped parameter models can also be employed to model Stage 1 palliation, taking advantage of a much lower computational cost, albeit missing the 3D anatomical component. Finally, analytical techniques, such as wave intensity analysis, can be employed to study the Norwood physiology, providing a mechanistic

Experimental investigation of a multi-stage humidification-dehumidification desalination system heated directly by a cylindrical Fresnel lens solar concentrator

International Nuclear Information System (INIS)

Wu, Gang; Zheng, Hongfei; Ma, Xinglong; Kutlu, Cagri; Su, Yuehong

2017-01-01

Highlights: • A solar desalination system heated directly by curved Fresnel lens concentrator. • Desalination system is based on the humidification-dehumidification process. • Four-stage multi-effect desalination system is proposed. • Condensation latent heat and residual heat in the brine are recycled and reutilized. • The maximum yield and GOR of the unit can reach 3.4 kg/h and 2.1, respectively. - Abstract: This study demonstrates a multi-stage humidification-dehumidification (HDH) solar desalination system heated directly by a cylindrical Fresnel lens concentrator. In this novel system, the solar radiation is sent directly into desalination unit. That is to say, the solar receiver and the evaporator of the system are a whole in which the black fillers in seawater directly absorb the concentrated solar lights to heat the seawater film to produce the evaporation. The configuration and working processes of the proposed design are described in detail. In order to analyze its performance, a small solar desalination prototype unit incorporated with a cylindrical Fresnel lens concentrator was designed and built in our laboratory. Using three-stage isothermal tandem heating mode, the variation of the fresh water yield rate and the absorber temperature with time were measured experimentally and were compared with theoretical calculations. The experimental results show that the maximum yield of the unit is about 3.4 kg/h, the maximum gained output ratio (GOR) is about 2.1, when the average intensity of solar radiation is about 867 W/m"2. This study indicates that the proposed system has the characteristics of compact structure and GOR high. It still can be improved when the design and operation are optimized further.

Pre-irradiation testing of experimental fuel elements

International Nuclear Information System (INIS)

Basova, B.G.; Davydov, E.F.; Dvoretskij, V.G.; Ivanov, V.B.; Syuzev, V.N.; Timofeev, G.A.; Tsykanov, V.A.

1979-01-01

The problems of testing of experimental fuel elements of nuclear reactors on the basis of complex accountancy of the factors defining operating capacity of the fuel elements are considered. The classification of the parameters under control and the methods of initial technological testing, including testing of the fuel product, cladding and fished fuel element, is given. The requirements to the apparatus used for complex testing are formulated. One of the possible variants of representation of the information obtained in the form of the input certificate of a single fuel element under study is proposed. The processing flowsheet of the gathered information using the computer is given. The approach under consideration is a methodological basis of investigation of fuel element operating life at the testing stage of the experimental fuel elements

Probability Judgements in Multi-Stage Problems : Experimental Evidence of Systematic Biases

NARCIS (Netherlands)

Gneezy, U.

1996-01-01

We report empirical evidence that in problems of random walk with positive drift, bounded rationality leads individuals to under-estimate the probability of success in the long run.In particular, individuals who were given the stage by stage probability distribution failed to aggregate this

Damage threshold of lithium niobate crystal under single and multiple femtosecond laser pulses: theoretical and experimental study

International Nuclear Information System (INIS)

Meng, Qinglong; Zhang, Bin; Zhong, Sencheng; Zhu, Liguo

2016-01-01

The damage threshold of lithium niobate crystal under single and multiple femtosecond laser pulses has been studied theoretically and experimentally. Firstly, the model for the damage threshold prediction of crystal materials based on the improved rate equation has been proposed. Then, the experimental measure method of the damage threshold of crystal materials has been given in detail. On the basis, the variation of the damage threshold of lithium niobate crystal with the pulse duration has also been analyzed quantitatively. Finally, the damage threshold of lithium niobate crystal under multiple laser pulses has been measured and compared to the theoretical results. The results show that the transmittance of lithium niobate crystal is almost a constant when the laser pulse fluence is relative low, whereas it decreases linearly with the increase in the laser pulse fluence below the damage threshold. The damage threshold of lithium niobate crystal increases with the increase in the duration of the femtosecond laser pulse. And the damage threshold of lithium niobate crystal under multiple laser pulses is obviously lower than that irradiated by a single laser pulse. The theoretical data fall in good agreement with the experimental results. (orig.)

Two-Stage n-PSK Partitioning Carrier Phase Recovery Scheme for Circular mQAM Coherent Optical Systems

DEFF Research Database (Denmark)

Rodrigo Navarro, Jaime; Kakkar, Aditya; Pang, Xiaodan

2016-01-01

(ΔνTs) tolerance is achieved compared to the single-stage n-PSK partitioning scheme. Superior performance in the ΔνTs tolerance compared to the blind phase search algorithm is also reported. The relative improvements with respect to other CPR schemes are also validated experimentally for a 28-Gbaud C......A novel two-stage n-PSK partitioning carrier phase recovery (CPR) scheme for circular multilevel quadrature amplitude modulation (C-mQAM) constellations is presented. The first stage of the algorithm provides an initial rough estimation of the received constellation, which is utilized in the second...... stage for CPR. The performance of the proposed algorithm is studied through extensive simulations at the forward error correction bit error rate targets of 3.8 × 10−3 and 1 × 10−2 and is compared with different CPR algorithms. A significant improvement in the combined linewidth symbol duration product...

Mathematical modeling of a continuous alcoholic fermentation process in a two-stage tower reactor cascade with flocculating yeast recycle.

Science.gov (United States)

de Oliveira, Samuel Conceição; de Castro, Heizir Ferreira; Visconti, Alexandre Eliseu Stourdze; Giudici, Reinaldo

2015-03-01

Experiments of continuous alcoholic fermentation of sugarcane juice with flocculating yeast recycle were conducted in a system of two 0.22-L tower bioreactors in series, operated at a range of dilution rates (D 1 = D 2 = 0.27-0.95 h(-1)), constant recycle ratio (α = F R /F = 4.0) and a sugar concentration in the feed stream (S 0) around 150 g/L. The data obtained in these experimental conditions were used to adjust the parameters of a mathematical model previously developed for the single-stage process. This model considers each of the tower bioreactors as a perfectly mixed continuous reactor and the kinetics of cell growth and product formation takes into account the limitation by substrate and the inhibition by ethanol and biomass, as well as the substrate consumption for cellular maintenance. The model predictions agreed satisfactorily with the measurements taken in both stages of the cascade. The major differences with respect to the kinetic parameters previously estimated for a single-stage system were observed for the maximum specific growth rate, for the inhibition constants of cell growth and for the specific rate of substrate consumption for cell maintenance. Mathematical models were validated and used to simulate alternative operating conditions as well as to analyze the performance of the two-stage process against that of the single-stage process.

Characteristics and Sampling Efficiencies of Two Impactor Bioaerosol Samplers: MAS-100(Registered) (Microbial Air Monitoring System) and Single-Stage Andersen Viable Microbial Samplers

National Research Council Canada - National Science Library

Hottell, K

2004-01-01

.... A petri dish with agar is used as the impaction surface for these samplers. The MAS-l00 is a single-stage impactor that aspirates air through a 400-hole perforated entry plate onto an agar plate at an airflow rate of 100 L/min...

Comparison of CFD-calculations of centrifugal compressor stages by NUMECA Fine Turbo and ANSYS CFX programs

Science.gov (United States)

Galerkin, Y. B.; Voinov, I. B.; Drozdov, A. A.

2017-08-01

Computational Fluid Dynamics (CFD) methods are widely used for centrifugal compressors design and flow analysis. The calculation results are dependent on the chosen software, turbulence models and solver settings. Two of the most widely applicable programs are NUMECA Fine Turbo and ANSYS CFX. The objects of the study were two different stages. CFD-calculations were made for a single blade channel and for full 360-degree flow paths. Stage 1 with 3D impeller and vaneless diffuser was tested experimentally. Its flow coefficient is 0.08 and loading factor is 0.74. For stage 1 calculations were performed with different grid quality, a different number of cells and different models of turbulence. The best results have demonstrated the Spalart-Allmaras model and mesh with 1.854 million cells. Stage 2 with return channel, vaneless diffuser and 3D impeller with flow coefficient 0.15 and loading factor 0.5 was designed by the known Universal Modeling Method. Its performances were calculated by the well identified Math model. Stage 2 performances by CFD calculations shift to higher flow rate in comparison with design performances. The same result was obtained for stage 1 in comparison with measured performances. Calculated loading factor is higher in both cases for a single blade channel. Loading factor performance calculated for full flow path (“360 degrees”) by ANSYS CFX is in satisfactory agreement with the stage 2 design performance. Maximum efficiency is predicted accurately by the ANSYS CFX “360 degrees” calculation. “Sector” calculation is less accurate. Further research is needed to solve the problem of performances mismatch.

Experimental-theoretical approach to carbon monoxide density calculation at the incipient stage of the fire indoors

Science.gov (United States)

Puzach, S. V.; Suleykin, E. V.; Akperov, R. G.; Nguyen, T. D.

2017-11-01

A new experimental-theoretical approach to the toxic gases concentrations assessment in case of fire indoors is offered. The analytical formulas for calculation of CO average volume density are received. These formulas do not contain the geometrical sizes of the room and surfaces dimensions of combustible materials and, therefore, are valid under conditions of as a small-scale fire as a large-scale fire. A small-scale experimental installation for modeling fire thermal and gas dynamics in the closed or open thermodynamic system has been designed. The results of the experiments on determining dependencies of CO average volume density from average volume temperature and oxygen average volume density as well as dependencies of specific coefficients of CO emission and specific mass rates of the combustible material gasification from the time of tests during the burning of wood, transformer oil and PVC cables shield are presented. The results of numerical experiments on CO density calculation in small and large scale rooms using the proposed analytical solutions, integral, zone and field models for calculation of fire thermal and gas dynamics are presented. The comparison with the experimental data obtained by the authors and given in the literature has been performed. It is shown that CO density calculation in the full-scale room at the incipient stage of the fire can be carried out taking into account only the experimental dependences of CO from temperature or O2 density, that have been obtained from small-scale experiments. Therefore the solution of the equation of carbon monoxide mass conservation law is not necessary.

Single-Stage Treatment of Osteomyelitis for Digital Salvage by Using an Antibiotic-Eluting, Methylmethacrylate Joint-Spanning Spacer.

Science.gov (United States)

Aimé, Victoria L; Kidwell, John T; Webb, Leland H

2017-06-01

Osteomyelitis of the digit is a challenging problem that can result in amputation. We describe 13 cases of osteomyelitis involving bones of the hand managed with a novel technique. We reviewed records of 12 patients (13 digits) who had joint-spanning, antibiotic-eluting (tobramycin or vancomycin), methylmethacrylate spacers placed as definitive, single-stage treatment for digital osteomyelitis. The primary outcome was digit salvage. Secondary outcomes were infection eradication (no recurrence at 3 months) and spacer removal. Patients were followed up until the infection resolved (ie, no cutaneous signs of infection, including pain, erythema, or swelling). At a mean of 24 months, 10 of 13 infections had successful one-stage treatment. One patient required a second operation to revise a soft tissue flap but the spacer remained in place. Two spacers were removed because of malalignment. An antibiotic-eluting methylmethacrylate spacer is an innovative treatment for digital osteomyelitis. In 12 consecutive patients (13 digits), we successfully salvaged the digit. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Feasibility of a single-stage tracheostomy decannulation protocol with endoscopy in adult patients.

Science.gov (United States)

Cohen, Oded; Tzelnick, Sharon; Lahav, Yonatan; Stavi, Dekel; Shoffel-Havakuk, Hagit; Hain, Moshe; Halperin, Doron; Adi, Nimrod

2016-09-01

Gradual decrease in tube size and tube capping are considered the standard of care for tracheostomy decannulation. Both of these actions result in increased airway resistance. Immediate decannulation may offer a more tolerable approach. To assess the feasibility of immediate tracheostomy decannulation compared with the traditional decannulation methods. This study is a single institute, case-control retrospective study of patients between the years 2009 to 2014. The study group included all patients who underwent immediate decannulation, whereas the control group comprised patients who underwent traditional staged decannulation. An immediate decannulation protocol included admission to the intensive care unit, a comprehensive evaluation, decannulation, 24 hours of monitoring, and observation until discharge. Twenty-nine patients were included in the study group and 20 in the control group. No significant statistical difference was found between the two groups in the patients' medical history and tracheostomy data, except for the Acute Physiology and Chronic Health Evaluation II score and duration of the deflated cuff, which were significantly higher in the control group. A significant difference was found in the complication rate between the groups. In the staged decannulation group, four patients failed decannulation and required reinsertion of the tracheostomy cannula, whereas there were no such failures in the immediate decannulation group. Hospitalization duration after decannulation of the study group patients was significantly shorter than that of the control group. Immediate decannulation may offer a safe alternative for weaning from tracheostomy. It may also reduce the duration of the weaning process and hospitalization. 3b Laryngoscope, 126:2057-2062, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Reducing the Entrainment of Gangue Fines in Low Grade Microcrystalline Graphite Ore Flotation Using Multi-Stage Grinding-Flotation Process

Directory of Open Access Journals (Sweden)

Xiaoqing Weng

2017-03-01

Full Text Available A suitable grinding fineness and flow-sheet could potentially reduce the mechanical entrainment of gangue minerals in the flotation process of microcrystalline graphite. In this study, the suitable grinding fineness of a commercial graphite ore was estimated by mineralogy analysis and laboratory grind-flotation tests. The target grind size of this ore should be 92% passing 74 μm based on the mineralogical evaluation and the flotation performance. A comparison of a single-stage and a three-stage grinding circuit was conducted. Experimental results demonstrated that the three-stage grinding circuit could effectively improve the separation effect, which was attributed to the reduction of slimes. In the end, a more desirable beneficiation result was obtained with the application of three-stage grinding-flotation process by minimizing gangue entrainment.

Design and control of a decoupled two degree of freedom translational parallel micro-positioning stage.

Science.gov (United States)

Lai, Lei-Jie; Gu, Guo-Ying; Zhu, Li-Min

2012-04-01

This paper presents a novel decoupled two degrees of freedom (2-DOF) translational parallel micro-positioning stage. The stage consists of a monolithic compliant mechanism driven by two piezoelectric actuators. The end-effector of the stage is connected to the base by four independent kinematic limbs. Two types of compound flexure module are serially connected to provide 2-DOF for each limb. The compound flexure modules and mirror symmetric distribution of the four limbs significantly reduce the input and output cross couplings and the parasitic motions. Based on the stiffness matrix method, static and dynamic models are constructed and optimal design is performed under certain constraints. The finite element analysis results are then given to validate the design model and a prototype of the XY stage is fabricated for performance tests. Open-loop tests show that maximum static and dynamic cross couplings between the two linear motions are below 0.5% and -45 dB, which are low enough to utilize the single-input-single-out control strategies. Finally, according to the identified dynamic model, an inversion-based feedforward controller in conjunction with a proportional-integral-derivative controller is applied to compensate for the nonlinearities and uncertainties. The experimental results show that good positioning and tracking performances are achieved, which verifies the effectiveness of the proposed mechanism and controller design. The resonant frequencies of the loaded stage at 2 kg and 5 kg are 105 Hz and 68 Hz, respectively. Therefore, the performance of the stage is reasonably good in term of a 200 N load capacity. © 2012 American Institute of Physics

Experimental assessment of pre-turbo aftertreatment configurations in a single stage turbocharged diesel engine. Part 1: Steady-state operation

OpenAIRE

Luján, José M.; Bermúdez, Vicente; Piqueras, P.; Garcia Afonso, Oscar

2015-01-01

Diesel oxidation catalysts and diesel particulate filters are standard aftertreatment systems in Diesel engines which are traditionally placed downstream of the turbine. However, pre-turbo aftertreatment configurations are being approached as a way to improve the aftertreatment performance in terms of light-off and passive regeneration. This exhaust line architecture can also benefit fuel economy. The objective of this work is to analyse experimentally how the pre-turbo aftertreatment placeme...

Open-Lake Experimental Investigation of Azimuth Angle Estimation Using a Single Acoustic Vector Sensor

Directory of Open Access Journals (Sweden)

Anbang Zhao

2018-01-01

Full Text Available Five well-known azimuth angle estimation methods using a single acoustic vector sensor (AVS are investigated in open-lake experiments. A single AVS can measure both the acoustic pressure and acoustic particle velocity at a signal point in space and output multichannel signals. The azimuth angle of one source can be estimated by using a single AVS in a passive sonar system. Open-lake experiments are carried out to evaluate how these different techniques perform in estimating azimuth angle of a source. The AVS that was applied in these open-lake experiments is a two-dimensional accelerometer structure sensor. It consists of two identical uniaxial velocity sensors in orthogonal orientations, plus a pressure sensor—all in spatial collocation. These experimental results indicate that all these methods can effectively realize the azimuth angle estimation using only one AVS. The results presented in this paper reveal that AVS can be applied in a wider range of application in distributed underwater acoustic systems for passive detection, localization, classification, and so on.

Rating the methodological quality of single-subject designs and n-of-1 trials: introducing the Single-Case Experimental Design (SCED) Scale.

Science.gov (United States)

Tate, Robyn L; McDonald, Skye; Perdices, Michael; Togher, Leanne; Schultz, Regina; Savage, Sharon

2008-08-01

Rating scales that assess methodological quality of clinical trials provide a means to critically appraise the literature. Scales are currently available to rate randomised and non-randomised controlled trials, but there are none that assess single-subject designs. The Single-Case Experimental Design (SCED) Scale was developed for this purpose and evaluated for reliability. Six clinical researchers who were trained and experienced in rating methodological quality of clinical trials developed the scale and participated in reliability studies. The SCED Scale is an 11-item rating scale for single-subject designs, of which 10 items are used to assess methodological quality and use of statistical analysis. The scale was developed and refined over a 3-year period. Content validity was addressed by identifying items to reduce the main sources of bias in single-case methodology as stipulated by authorities in the field, which were empirically tested against 85 published reports. Inter-rater reliability was assessed using a random sample of 20/312 single-subject reports archived in the Psychological Database of Brain Impairment Treatment Efficacy (PsycBITE). Inter-rater reliability for the total score was excellent, both for individual raters (overall ICC = 0.84; 95% confidence interval 0.73-0.92) and for consensus ratings between pairs of raters (overall ICC = 0.88; 95% confidence interval 0.78-0.95). Item reliability was fair to excellent for consensus ratings between pairs of raters (range k = 0.48 to 1.00). The results were replicated with two independent novice raters who were trained in the use of the scale (ICC = 0.88, 95% confidence interval 0.73-0.95). The SCED Scale thus provides a brief and valid evaluation of methodological quality of single-subject designs, with the total score demonstrating excellent inter-rater reliability using both individual and consensus ratings. Items from the scale can also be used as a checklist in the design, reporting and critical

Single-virus tracking approach to reveal the interaction of Dengue virus with autophagy during the early stage of infection

Science.gov (United States)

Chu, Li-Wei; Huang, Yi-Lung; Lee, Jin-Hui; Huang, Long-Ying; Chen, Wei-Jun; Lin, Ya-Hsuan; Chen, Jyun-Yu; Xiang, Rui; Lee, Chau-Hwang; Ping, Yueh-Hsin

2014-01-01

Dengue virus (DENV) is one of the major infectious pathogens worldwide. DENV infection is a highly dynamic process. Currently, no antiviral drug is available for treating DENV-induced diseases since little is known regarding how the virus interacts with host cells during infection. Advanced molecular imaging technologies are powerful tools to understand the dynamics of intracellular interactions and molecular trafficking. This study exploited a single-virus particle tracking technology to address whether DENV interacts with autophagy machinery during the early stage of infection. Using confocal microscopy and three-dimensional image analysis, we showed that DENV triggered the formation of green fluorescence protein-fused microtubule-associated protein 1A/1B-light chain 3 (GFP-LC3) puncta, and DENV-induced autophagosomes engulfed DENV particles within 15-min postinfection. Moreover, single-virus particle tracking revealed that both DENV particles and autophagosomes traveled together during the viral infection. Finally, in the presence of autophagy suppressor 3-methyladenine, the replication of DENV was inhibited and the location of DENV particles spread in cytoplasma. In contrast, the numbers of newly synthesized DENV were elevated and the co-localization of DENV particles and autophagosomes was detected while the cells were treated with autophagy inducer rapamycin. Taken together, we propose that DENV particles interact with autophagosomes at the early stage of viral infection, which promotes the replication of DENV.

Advantages of using a two-switch forward in single-stage power factor corrected power supplies

DEFF Research Database (Denmark)

Petersen, Lars

2000-01-01

A single-stage power factor corrected power supply using a two-switch forward is proposed to increase efficiency. The converter is operated in the DCM (discontinues conduction mode) and it is shown that this operation mode ensures the intermediate DC-bus to be controlled only by means of circuit...... supply has been implemented. The measured efficiency is between 85% and 88.5% in the range 30 W-500 W and the measured power factor at full load is 0.95....... parameters and therefore independent of load variations. The DCM operation often has a diminishing effect on the efficiency but by use of the two-switch topology high efficiency with minimum circuit complexity can be achieved in this mode. A 500 W 70 V prototype of the two-switch boost-forward PFC power...

Performance study of a heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system

International Nuclear Information System (INIS)

Zhang, Ning; Yin, Shao-You; Zhang, Li-Zhi

2016-01-01

Graphical abstract: A heat pump driven, hollow fiber membrane-based two-stage liquid desiccant air dehumidification system. - Highlights: • A two-stage hollow fiber membrane based air dehumidification is proposed. • It is heat pump driven liquid desiccant system. • Performance is improved 20% upon single stage system. • The optimal first to second stage dehumidification area ratio is 1.4. - Abstract: A novel compression heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system is presented. The liquid desiccant droplets are prevented from crossing over into the process air by the semi-permeable membranes. The isoenthalpic processes are changed to quasi-isothermal processes by the two-stage dehumidification processes. The system is set up and a model is proposed for simulation. Heat and mass capacities in the system, including the membrane modules, the condenser, the evaporator and the heat exchangers are modeled in detail. The model is also validated experimentally. Compared with a single-stage dehumidification system, the two-stage system has a lower solution concentration exiting from the dehumidifier and a lower condensing temperature. Thus, a better thermodynamic system performance is realized and the COP can be increased by about 20% under the typical hot and humid conditions in Southern China. The allocations of heat and mass transfer areas in the system are also investigated. It is found that the optimal regeneration to dehumidification area ratio is 1.33. The optimal first to second stage dehumidification area ratio is 1.4; and the optimal first to second stage regeneration area ratio is 1.286.

Experimental setup for Single Event Effects at the São Paulo 8UD Pelletron Accelerator

Science.gov (United States)

Aguiar, V. A. P.; Added, N.; Medina, N. H.; Macchione, E. L. A.; Tabacniks, M. H.; Aguirre, F. R.; Silveira, M. A. G.; Santos, R. B. B.; Seixas, L. E.

2014-08-01

In this work we present an experimental setup mounted in one of the beam lines at the São Paulo 8UD Pelletron Accelerator in order to study Single Event Effects in electronic devices. The basic idea is to use elastic scattering collisions to achieve a low-flux with a high-uniformity ion beam to irradiate several devices. 12C, 16O, 28Si, 35Cl and 63Cu beams were used to test the experimental setup. In this system it is possible to use efficiently LET values of 17 MeV/mg/cm2 for an external beam arrangement and up to 32 MeV/mg/cm2 for in-vacuum irradiation.

Experimental Evaluation of a Method for Turbocharging Four-Stroke, Single Cylinder, Internal Combustion Engines

Science.gov (United States)

Buchman, Michael; Winter, Amos

2015-11-01

Turbocharging an engine increases specific power, improves fuel economy, reduces emissions, and lowers cost compared to a naturally aspirated engine of the same power output. These advantages make turbocharging commonplace for multi-cylinder engines. Single cylinder engineers are not commonly turbocharged due to the phase lag between the exhaust stroke, which powers the turbocharger, and the intake stroke, when air is pumped into the engine. Our proposed method of turbocharging single cylinder engines is to add an ``air capacitor'' to the intake manifold, an additional volume that acts as a buffer to store compressed air between the exhaust and intake strokes, and smooth out the pressure pulses from the turbocharger. This talk presents experimental results from a single cylinder, turbocharged diesel engine fit with various sized air capacitors. Power output from the engine was measured using a dynamometer made from a generator, with the electrical power dissipated with resistive heating elements. We found that intake air density increases with capacitor size as theoretically predicted, ranging from 40 to 60 percent depending on heat transfer. Our experiment was able to produce 29 percent more power compared to using natural aspiration. These results validated that an air capacitor and turbocharger may be a simple, cost effective means of increasing the power density of single cylinder engines.

Numerical simulation of radial compressor stage

Science.gov (United States)

Syka, T.; Luňáček, O.

2013-04-01

Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

Numerical simulation of radial compressor stage

OpenAIRE

Luňáček O.; Syka T.

2013-01-01

Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

Experimental study of single-phase pressure drops in coarse particle beds

Energy Technology Data Exchange (ETDEWEB)

Clavier, R., E-mail: remi.clavier@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Chikhi, N., E-mail: nourdine.chikhi@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Fichot, F., E-mail: florian.fichot@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Quintard, M., E-mail: Michel.Quintard@imft.fr [Université de Toulouse, Allée Camille Soula, F-31400 Toulouse (France); INPT, UPS, Allée Camille Soula, F-31400 Toulouse (France); IMFT (Institut de Mécanique des Fluides de Toulouse), Allée Camille Soula, F-31400 Toulouse (France); CNRS, F-31400 Toulouse (France)

2017-02-15

Motivated by uncertainty reduction in nuclear debris beds coolability, experiments have been conducted on the CALIDE facility in order to investigate single-phase pressure losses in representative debris beds, i.e., high sphericity (>80%) particle beds with small size dispersion (from 1 mm to 10 mm), for which no validated model exists. In this paper, experimental results are presented and analyzed in order to identify a simple correlation for single-phase flow pressure losses generated in this kind of porous media in reflooding flowing conditions, which cover Darcy to weakly turbulent regimes. In the literature, it has been observed that their behavior can be accurately described by a Darcy–Forchheimer law, involving the sum of a linear term and a quadratic non-linear deviation, with respect to the filtration velocity. Expressions for the coefficients of the linear and quadratic terms are determined by assessing the possibility to evaluate equivalent diameters, i.e., characteristic lengths allowing correct predictions of the linear and quadratic terms by the Ergun equation. It has been observed that the Sauter diameter of particles allows a very precise prediction of the linear term, while the quadratic term can be predicted using the product of the Sauter diameter and a sphericity coefficient as an equivalent diameter.

Experimental study and modelisation of a pulse tube refrigerator

International Nuclear Information System (INIS)

Ravex, A.; Rolland, P.; Liang, J.

1992-01-01

A test bench for pulse tube refrigerator characterization has been built. In various configurations (basic pulse tube, orifice pulse tube and double inlet pulse tube), the ultimate temperature and the cooling power have been measured as a function of pressure wave amplitude and frequency for various geometries. A lowest temperature of 28 K has been achieved in a single staged double inlet configuration. A modelisation taking into account wall heat pumping, enthalpy flow and regenerator inefficiency is under development. Preliminary calculation results are compared with experimental data

Single stage: dorsolateral onlay buccal mucosal urethroplasty for long anterior urethral strictures using perineal route

Directory of Open Access Journals (Sweden)

Vikram Prabha

2016-06-01

Full Text Available ABSTRACT Objective To assess the outcome of single stage dorsolateral onlay buccal mucosal urethroplasty for long anterior urethral strictures (>4cm long using a perineal incision. Materials and Methods From August 2010 to August 2013, 20 patients underwent BMG urethroplasty. The cause of stricture was Lichen sclerosis in 12 cases (60%, Instrumentation in 5 cases (25%, and unknown in 3 cases (15%. Strictures were approached through a perineal skin incision and penis was invaginated into it to access the entire urethra. All the grafts were placed dorsolaterally, preserving the bulbospongiosus muscle, central tendon of perineum and one-sided attachement of corpus spongiosum. Procedure was considered to be failure if the patient required instrumentation postoperatively. Results Mean stricture length was 8.5cm (range 4 to 12cm. Mean follow-up was 22.7 months (range 12 to 36 months. Overall success rate was 85%. There were 3 failures (meatal stenosis in 1, proximal stricture in 1 and whole length recurrent stricture in 1. Other complications included wound infection, urethrocutaneous fistula, brownish discharge per urethra and scrotal oedema. Conclusion Dorsolateral buccal mucosal urethroplasty for long anterior urethral strictures using a single perineal incision is simple, safe and easily reproducible by urologists with a good outcome.

The influence of magnetic field strength in ionization stage on ion transport between two stages of a double stage Hall thruster

International Nuclear Information System (INIS)

Yu Daren; Song Maojiang; Li Hong; Liu Hui; Han Ke

2012-01-01

It is futile for a double stage Hall thruster to design a special ionization stage if the ionized ions cannot enter the acceleration stage. Based on this viewpoint, the ion transport under different magnetic field strengths in the ionization stage is investigated, and the physical mechanisms affecting the ion transport are analyzed in this paper. With a combined experimental and particle-in-cell simulation study, it is found that the ion transport between two stages is chiefly affected by the potential well, the potential barrier, and the potential drop at the bottom of potential well. With the increase of magnetic field strength in the ionization stage, there is larger plasma density caused by larger potential well. Furthermore, the potential barrier near the intermediate electrode declines first and then rises up while the potential drop at the bottom of potential well rises up first and then declines as the magnetic field strength increases in the ionization stage. Consequently, both the ion current entering the acceleration stage and the total ion current ejected from the thruster rise up first and then decline as the magnetic field strength increases in the ionization stage. Therefore, there is an optimal magnetic field strength in the ionization stage to guide the ion transport between two stages.

Orbital single particle tracking on a commercial confocal microscope using piezoelectric stage feedback

International Nuclear Information System (INIS)

Lanzanò, L; Gratton, E

2014-01-01

Single Particle Tracking (SPT) is a technique used to locate fluorescent particles with nanometer precision. In the orbital tracking method the position of a particle is obtained analyzing the distribution of intensity along a circular orbit scanned around the particle. In combination with an active feedback this method allows tracking of particles in 2D and 3D with millisecond temporal resolution. Here we describe a SPT setup based on a feedback approach implemented with minimal modification of a commercially available confocal laser scanning microscope, the Zeiss LSM 510, in combination with an external piezoelectric stage scanner. The commercial microscope offers the advantage of a user-friendly software interface and pre-calibrated hardware components. The use of an external piezo-scanner allows the addition of feedback into the system but also represents a limitation in terms of its mechanical response. We describe in detail this implementation of the orbital tracking method and discuss advantages and limitations. As an example of application to live cell experiments we perform the 3D tracking of acidic vesicles in live polarized epithelial cells. (paper)

Theoretical modelling and experimental investigation of single-phase and two-phase flow division at a tee-junction

International Nuclear Information System (INIS)

Lemonnier, H.; Hervieu, E.

1991-01-01

Phase separation in a tee-junction is modelled in the particular case of bubbly-flow. The model is based on a two-dimensional approach and hence, uses local equations. The first step consists in modelling the single-phase flow in the tee-junction. The free streamline theory is used to predict the flow of the continuous phase. The two recirculation zones which are presented in this case are predicted by the model. The second step consists in predicting the gas bubble paths as a result of the actions of the single-phase flow. Finally, the trajectories of gas bubbles are used to predict the separation characteristics of the tee-junction. Each step of the modelling procedure has been carefully tested by an in-depth experimental investigation. Excellent quantitative agreement is obtained between experimental results and model predictions. Moreover, the phase separation phenomenon is found to be clearly described by the model. (orig.)

A review of findings of a study of rocket based combined cycle engines applied to extensively axisymmetric single stage to orbit vehicles

Science.gov (United States)

Foster, Richard W.

1992-01-01

Extensively axisymmetric and non-axisymmetric Single Stage To Orbit (SSTO) vehicles are considered. The information is presented in viewgraph form and the following topics are presented: payload comparisons; payload as a percent of dry weight - a system hardware cost indicator; life cycle cost estimations; operations and support costs estimation; selected engine type; and rocket engine specific impulse calculation.

Single-stage multilevel soft-tissue surgery in the lower limbs with spastic cerebral palsy: Experience from a rehabilitation unit

Directory of Open Access Journals (Sweden)

Gupta Anupam

2008-01-01

Full Text Available Background: To assess the effect of single-stage multilevel soft-tissue surgery (Single Event Multiple Level Resections, SEMLR on deformities and locomotion in patients with cerebral palsy (CP with static contracture(s in lower limbs. Patients and Methods: Study included 34 patients (M:F, 23:11 with mean age of 9.53 ± 3.92 years (4-16 years. Among them 22 had diplegia and four each had quadriplegia and right and left hemiplegia. Fourteen patients (41.2% had their intelligence quotient (IQ in the normal range (IQ ≥ 80, while others had mental retardation (MR of varying severity: borderline MR (IQ = 70-79 in 12, mild MR (IQ = 50-69 in 5, and moderate MR (IQ = 35-49 in patients 3. All patients underwent surgery (total number of procedures 153, average 4.5 procedures/patient over a period of 30 months (April 2005 to September 2007. Improvement in functional abilities and locomotion was assessed using Gross Motor Functional Classification Scale (GMFCS scores and by physical examination. Results: Significant improvement in function was observed ( P = 0.000 after surgery when comparing the preoperative and postoperative GMFCS scores. All patients were maintaining ambulation at a mean follow-up duration of 13.12 ± 6.07 months (3-24 months, with five patients using knee-ankle-foot orthoses (KAFO, 22 using ankle-foot orthoses (AFO, and six patients using knee gaiters. Sixteen patients were using walker, and two were using crutches as assistive devices. Conclusion: This study suggests that CP patients with good trunk control and static contractures at multiple joints in the lower limbs can be made ambulant with single-stage multilevel soft-tissue surgery. It has to be a team effort of the surgeon and the rehabilitation team in the postoperative period for the attainment of satisfactory goal.

Numerical simulation of radial compressor stage

Directory of Open Access Journals (Sweden)

Luňáček O.

2013-04-01

Full Text Available Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

Oxygen uptake during peak graded exercise and single-stage fatigue tests of wheelchair propulsion in manual wheelchair users and the able-bodied.

Science.gov (United States)

Keyser, R E; Rodgers, M M; Gardner, E R; Russell, P J

1999-10-01

To determine if a single-stage, submaximal fatigue test on a wheelchair ergometer would result in higher than expected energy expenditure. An experimental survey design contrasting physiologic responses during peak graded exercise tests and fatigue tests. A rehabilitation science laboratory that included a prototypical wheelchair ergometer, open-circuit spirometry system, and heart rate monitor. Nine able-bodied non-wheelchair users (the NWC group: 6 men and 3 women, mean +/- SD age 30 +/- 7yrs) and 15 manual wheelchair users (the WC group: 12 men and 3 women, age 40 +/- 9yrs, time in wheelchair 16 +/- 9yrs). No subject had any disease, medication regimen, or upper body neurologic, orthopedic, or other condition that would limit wheelchair exercise. Peak oxygen uptake (VO2) for graded exercise testing and during fatigue testing, using a power output corresponding to 75% peak aerobic capacity on graded exercise test. In the WC group, VO2 at 6 minutes of fatigue testing was not significantly different from peak VO2. In the NWC group, VO2 was similar to the expected level throughout fatigue testing. Energy expenditure was higher than expected in the WC group but not in the NWC group. Fatigue testing may provide a useful evaluation of cardiorespiratory status in manual wheelchair users.

Analysis, Design, and Experimental Verification of A Synchronous Reference Frame Voltage Control for Single-Phase Inverters

DEFF Research Database (Denmark)

Monfared, Mohammad; Golestan, Saeed; Guerrero, Josep M.

2014-01-01

Control of three-phase power converters in the synchronous reference frame is now a mature and well developed research topic. However, for single-phase converters, it is not as well-established as three-phase applications. This paper deals with the design of a synchronous reference frame multi-lo...... on a frequency response approach is presented. Finally, the theoretical achievements are supported by experimental results.......-loop control strategy for single phase inverter-based islanded distributed generation (DG) systems. The proposed controller uses a synchronous reference frame PI (SRFPI) controller to regulate the instantaneous output voltage, a capacitor current shaping loop in the stationary reference frame to provide active...

Creep in single crystals of γ single phase Ni-20Cr alloy and evolution of dynamic recrystallization

International Nuclear Information System (INIS)

Matsuo, T.; Terada, Y.; Takahashi, S.; Ishiwari, Y.

2000-01-01

The creep rate - time and the creep rate - strain curves of the single crystals of γ single phase Ni-20 mass%Cr alloy have been investigated at 1173 K under the wide stress range of 19.6 to 98 MPa, and compared with those of polycrystals. The orientation corresponding to the stress axis of the single crystals were chosen within the standard stereographic triangle. The creep curve in the Ni-20 mass%Cr single crystal consists of a transient stage and an accelerating stage without a steady state stage. The transient stage has two steps. In the first step, the creep rate slightly decreases, and in the second step, the decrease in creep rate becomes prominent with increasing the testing time. With decreasing the stress, the extension of transient stage becomes prominent, and by this extension, the decreasing ratio of the creep rate in transient stage is enlarged. At the lowest stress of 19.6 MPa, the most prominent extension of transient stage and the more than two order decrease in creep rate in transient stage are detected. The creep interrupting tests have been conducted at the stress of 29.4 MPa in the strain range of 0.1 to 0.6 to examine the appearance of dynamically recrystallized grains. At the strain of 0.1 corresponding to the end of the first step in transient stage, a straight subboundary parallel to slip plane appears in a wide distance of a few hundreds micrometers. With increasing the strain, the straight subboundary turns to waved one. At the strain showing the minimum creep rate, a lot of evolved subgrains appear. At the strain corresponding to the early stage of accelerating creep, dynamically recrystallized grains appear. It is confirmed that the onset of accelerating creep well corresponds to the appearance of dynamically recrystallized grains. In the single crystal creep ruptured, the whole gage portion turns to polycrystal with equiaxed grains having a diameter of 150 μm. (orig.)

Single stage reduction and stabilization of basilar invagination after failed prior fusion surgery in children with Down's syndrome.

Science.gov (United States)

Hedequist, Daniel; Bekelis, Kimon; Emans, John; Proctor, Mark R

2010-02-15

We describe an innovative single-stage reduction and stabilization technique using modern cervical instrumentation. We hypothesis modern instrumentation has made more aggressive surgical corrections possible and has reduced the need for transoral resection of the odontoid and traction reduction in children with basilar invagination. Craniocervical junction abnormalities, including atlantoaxial instability and progressive basilar invagination, are relatively common phenomenon in Down's syndrome patients, and can lead to chronic progressive neurologic deficits, catastrophic injury, and death. This patient population also can be a difficult one in which to perform successful stabilization and fusion. We reviewed the records and films on 2 children with Down's syndrome and atlantoaxial instability who had undergone prior occipital-cervical fusion and then presented with symptomatic progressive basilar invagination due to atlantoaxial displacement. In both cases, the children had progressive symptoms of spinal cord and brain stem compression. Multiple approaches for surgical correction, including preoperative traction and transoral odontoid resection, were considered, but ultimately it was elected to perform a single stage posterior operation. In both patients, we performed fusion takedown, intraoperative realignment with reduction of the basilar invagination, and stabilization using modern occipito-cervical instrumentation. In both children, excellent cranio-cervical realignment was achieved; along with successful fusion and improvement in clinical symptoms. In this article we will discuss the clinical cases and review the background of craniocervical junction abnormalities in Down's syndrome patients. We hypothesis modern instrumentation has made more aggressive surgical corrections possible and has reduced the need for transoral resection of the odontoid and traction reduction in children with basilar invagination.

A novel, fast and efficient single-sensor automatic sleep-stage classification based on complementary cross-frequency coupling estimates.

Science.gov (United States)

Dimitriadis, Stavros I; Salis, Christos; Linden, David

2018-04-01

Limitations of the manual scoring of polysomnograms, which include data from electroencephalogram (EEG), electro-oculogram (EOG), electrocardiogram (ECG) and electromyogram (EMG) channels have long been recognized. Manual staging is resource intensive and time consuming, and thus considerable effort must be spent to ensure inter-rater reliability. As a result, there is a great interest in techniques based on signal processing and machine learning for a completely Automatic Sleep Stage Classification (ASSC). In this paper, we present a single-EEG-sensor ASSC technique based on the dynamic reconfiguration of different aspects of cross-frequency coupling (CFC) estimated between predefined frequency pairs over 5 s epoch lengths. The proposed analytic scheme is demonstrated using the PhysioNet Sleep European Data Format (EDF) Database with repeat recordings from 20 healthy young adults. We validate our methodology in a second sleep dataset. We achieved very high classification sensitivity, specificity and accuracy of 96.2 ± 2.2%, 94.2 ± 2.3%, and 94.4 ± 2.2% across 20 folds, respectively, and also a high mean F1 score (92%, range 90-94%) when a multi-class Naive Bayes classifier was applied. High classification performance has been achieved also in the second sleep dataset. Our method outperformed the accuracy of previous studies not only on different datasets but also on the same database. Single-sensor ASSC makes the entire methodology appropriate for longitudinal monitoring using wearable EEG in real-world and laboratory-oriented environments. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Experimental setup for Single Event Effects at the São Paulo 8UD Pelletron Accelerator

Energy Technology Data Exchange (ETDEWEB)

Aguiar, V.A.P. [Instituto de Física da Universidade de São Paulo, São Paulo, SP (Brazil); Added, N., E-mail: nemitala@if.usp.br [Instituto de Física da Universidade de São Paulo, São Paulo, SP (Brazil); Medina, N.H.; Macchione, E.L.A.; Tabacniks, M.H.; Aguirre, F.R. [Instituto de Física da Universidade de São Paulo, São Paulo, SP (Brazil); Silveira, M.A.G.; Santos, R.B.B. [Centro Universitário da FEI, São Bernardo do Campo, SP (Brazil); Seixas, L.E. [Centro de Tecnologia da Informação Renato Archer, Campinas, SP (Brazil)

2014-08-01

In this work we present an experimental setup mounted in one of the beam lines at the São Paulo 8UD Pelletron Accelerator in order to study Single Event Effects in electronic devices. The basic idea is to use elastic scattering collisions to achieve a low-flux with a high-uniformity ion beam to irradiate several devices. {sup 12}C, {sup 16}O, {sup 28}Si, {sup 35}Cl and {sup 63}Cu beams were used to test the experimental setup. In this system it is possible to use efficiently LET values of 17 MeV/mg/cm{sup 2} for an external beam arrangement and up to 32 MeV/mg/cm{sup 2} for in-vacuum irradiation.

A Rocket Powered Single-Stage-to-Orbit Launch Vehicle With U.S. and Soviet Engineers

Science.gov (United States)

MacConochie, Ian O.; Stnaley, Douglas O.

1991-01-01

A single-stage-to-orbit launch vehicle is used to assess the applicability of Soviet Energia high-pressure-hydrocarbon engine to advanced U.S. manned space transportation systems. Two of the Soviet engines are used with three Space Shuttle Main Engines. When applied to a baseline vehicle that utilized advanced hydrocarbon engines, the higher weight of the Soviet engines resulted in a 20 percent loss of payload capability and necessitated a change in the crew compartment size and location from mid-body to forebody in order to balance the vehicle. Various combinations of Soviet and Shuttle engines were evaluated for comparison purposes, including an all hydrogen system using all Space Shuttle Main Engines. Operational aspects of the baseline vehicle are also discussed. A new mass properties program entitles Weights and Moments of Inertia (WAMI) is used in the study.

Single cell analysis facilitates staging of Blimp1-dependent primordial germ cells derived from mouse embryonic stem cells.

Directory of Open Access Journals (Sweden)

John J Vincent

Full Text Available The cell intrinsic programming that regulates mammalian primordial germ cell (PGC development in the pre-gonadal stage is challenging to investigate. To overcome this we created a transgene-free method for generating PGCs in vitro (iPGCs from mouse embryonic stem cells (ESCs. Using labeling for SSEA1 and cKit, two cell surface molecules used previously to isolate presumptive iPGCs, we show that not all SSEA1+/cKit+ double positive cells exhibit a PGC identity. Instead, we determined that selecting for cKit(bright cells within the SSEA1+ fraction significantly enriches for the putative iPGC population. Single cell analysis comparing SSEA1+/cKit(bright iPGCs to ESCs and embryonic PGCs demonstrates that 97% of single iPGCs co-express PGC signature genes Blimp1, Stella, Dnd1, Prdm14 and Dazl at similar levels to e9.5-10.5 PGCs, whereas 90% of single mouse ESC do not co-express PGC signature genes. For the 10% of ESCs that co-express PGC signature genes, the levels are significantly lower than iPGCs. Microarray analysis shows that iPGCs are transcriptionally distinct from ESCs and repress gene ontology groups associated with mesoderm and heart development. At the level of chromatin, iPGCs contain 5-methyl cytosine bases in their DNA at imprinted and non-imprinted loci, and are enriched in histone H3 lysine 27 trimethylation, yet do not have detectable levels of Mvh protein, consistent with a Blimp1-positive pre-gonadal PGC identity. In order to determine whether iPGC formation is dependent upon Blimp1, we generated Blimp1 null ESCs and found that loss of Blimp1 significantly depletes SSEA1/cKit(bright iPGCs. Taken together, the generation of Blimp1-positive iPGCs from ESCs constitutes a robust model for examining cell-intrinsic regulation of PGCs during the Blimp1-positive stage of development.

The effect of seasonal harvesting on a single-species discrete population model with stage structure and birth pulses

International Nuclear Information System (INIS)

Gao Shujing; Chen Lansun

2005-01-01

In this paper, we propose an exploited single-species discrete model with stage structure for the dynamics in a fish population for which births occur in a single pulse once per time period. Using the stroboscopic map, we obtain an exact cycle of the system, and obtain the threshold conditions for its stability. Bifurcation diagrams are constructed with the birth rate as the bifurcation parameter, and these are observed to display complex dynamic behaviors, including chaotic bands with period windows, pitch-fork and tangent bifurcation. This suggests that birth pulse provides a natural period or cyclicity that makes the dynamical behavior more complex. Moreover, we show that the timing of harvesting has a strong impact on the persistence of the fish population, on the volume of mature fish stock and on the maximum annual-sustainable yield. An interesting result is obtained that, after the birth pulse, the earlier culling the mature fish, the larger harvest can tolerate

Many-Objective Particle Swarm Optimization Using Two-Stage Strategy and Parallel Cell Coordinate System.

Science.gov (United States)

Hu, Wang; Yen, Gary G; Luo, Guangchun

2017-06-01

It is a daunting challenge to balance the convergence and diversity of an approximate Pareto front in a many-objective optimization evolutionary algorithm. A novel algorithm, named many-objective particle swarm optimization with the two-stage strategy and parallel cell coordinate system (PCCS), is proposed in this paper to improve the comprehensive performance in terms of the convergence and diversity. In the proposed two-stage strategy, the convergence and diversity are separately emphasized at different stages by a single-objective optimizer and a many-objective optimizer, respectively. A PCCS is exploited to manage the diversity, such as maintaining a diverse archive, identifying the dominance resistant solutions, and selecting the diversified solutions. In addition, a leader group is used for selecting the global best solutions to balance the exploitation and exploration of a population. The experimental results illustrate that the proposed algorithm outperforms six chosen state-of-the-art designs in terms of the inverted generational distance and hypervolume over the DTLZ test suite.

Single-stage Kanban system with deterioration failures and condition-based preventive maintenance

International Nuclear Information System (INIS)

Xanthopoulos, A.S.; Koulouriotis, D.E.; Botsaris, P.N.

2015-01-01

Despite the fact that the fields of pull type production control policies and condition-based preventive maintenance have much in common contextually, they have evolved independently up to now. In this investigation, an attempt is made to bridge the gap between these two branches of knowledge by introducing the single-stage Kanban system with deterioration failures and condition-based preventive maintenance. The formalism of continuous time Markov chains is used to model the system and expressions for eight performance metrics are derived. Two important, from a managerial perspective, constrained optimization problems for the proposed model are defined where the objective is the simultaneous optimization of the Kanban policy, the preventive maintenance policy and the inspection schedule under conflicting performance criteria. Multiple instances of each optimization problem are solved by means of the augmented Lagrangian genetic algorithm. The results from the optimization trials coupled by the results from extensive numerical examples facilitate the thorough investigation of the system’s behaviour. - Highlights: • Kanban system with deterioration failures and preventive maintenance is introduced. • The system is modeled as a continuous time Markov chain. • Expressions for eight performance metrics are derived. • The behavior of the system is studied through numerical examples. • Optimization results for selected performance metrics are presented

Scour around bridge piers in the stage hydrograph

Energy Technology Data Exchange (ETDEWEB)

Ahn, Sang Jin; Kim, Ung Yong [Chungbuk National University, Chongju (Korea, Republic of); Yon, Kee Seuk; Kim, Jong Sub [Taejon University of Technology, Taejon (Korea, Republic of)

1997-08-31

This study aims at examining closely the scour around a pier due to irregular water stage changes during flood. At the Sangye bridge is located lowermost downstream of the Bocheong stream in the Kum River, the IHP experimental watershed. For this purpose, we have analyzed the change of scour depths due to stage hydrographs of experimental basin by a simulation. To examine the scour phenomenon around a pier due to irregular stage change in flood, we have analyzed the change of scour depth corresponding to stage hydrograph of field watershed after verification of model channel. From this study, the following conclusions are made: First, in case of predicting the maximum scour depth around a pier with stage hydrograph in the state of steady flow, we should choose the highest stage. Second, after increasing the stage, the equilibrium scour depth became smaller than the maximum scour depth. therefore, in case of estimating the maximum scour depth in rivers, it is recommended that we should consider additional scour depth which is reduced by infilling the sediments. (author). 25 refs., 6 tabs., 11 figs.

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

International Nuclear Information System (INIS)

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

2003-01-01

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)

An experimental two-stage rat model of lung carcinoma initiated by radon exposure

International Nuclear Information System (INIS)

Poncy, J.L.; Laroque, P.; Fritsch, P.; Monchaux, G.; Masse, R.; Chameaud, J.

1992-01-01

We present the results of a two-stage biological model of lung carcinogenesis in rats. The histogenesis of these tumors was examined, and DNA content of lung cells was measured by flow cytometry during the evolving neoplastic stage. Tumors were induced in rat lungs after radon inhalation (1600 WLM) followed by a promoter treatment; six intramuscular injections of 5,6-benzoflavone (25 mg/kg of body weight/injection) every 2 wk. Less than 3 mo after the first injection of benzoflavone, squamous cell carcinoma was observed in the lungs of all rats exposed to radon. The preneoplastic lesions gradually developed as follows: hyperplastic bronchiolar-type cells migrated to the alveoli from cells that proliferated in bronchioles and alveolar ducts; initial lesions were observed in almost all respiratory bronchioles. From some hyperplasias, epidermoid metaplasias arose distally, forming nodular epidermoid lesions in alveoli, which progressed to form squamous papilloma and, finally, epidermoid carcinomas. The histogenesis of these experimentally induced epidermoid carcinomas showed the bronchioloalveolar origin of the tumor. This factor must be considered when comparing these with human lesions; in humans, lung epidermoid carcinomas are thought to arise mainly in the first bronchial generations. The labeling index of pulmonary tissue after incorporation of 3 H-thymidine by the cells was 0.2% in control rats. This index reached a value of 1 to 2% in the hyperplastic area of the bronchioles and 10 to 15% in epidermoid nodules and epidermoid tumors, respectively. DNA cytometric analysis was performed on cell suspensions obtained after enzymatic treatment of paraffin sections of lungs from rats sacrificed during different stags of neoplastic transformations. Data showed the early appearance of a triploid cell population that grew during the evolution of nodular epidermoid lesions to epidermoid carcinomas

Analysis of a single-atom dipole trap

International Nuclear Information System (INIS)

Weber, Markus; Volz, Juergen; Saucke, Karen; Kurtsiefer, Christian; Weinfurter, Harald

2006-01-01

We describe a simple experimental technique which allows us to store a single 87 Rb atom in an optical dipole trap. Due to light-induced two-body collisions during the loading stage of the trap the maximum number of captured atoms is locked to one. This collisional blockade effect is confirmed by the observation of photon antibunching in the detected fluorescence light. The spectral properties of single photons emitted by the atom were studied with a narrow-band scanning cavity. We find that the atomic fluorescence spectrum is dominated by the spectral width of the exciting laser light field. In addition we observe a spectral broadening of the atomic fluorescence light due to the Doppler effect. This allows us to determine the mean kinetic energy of the trapped atom corresponding to a temperature of 105 μK. This simple single-atom trap is the key element for the generation of atom-photon entanglement required for future applications in quantum communication and a first loophole-free test of Bell's inequality

Optimized design and performance of a shared pump single clad 2 μm TDFA

Science.gov (United States)

Tench, Robert E.; Romano, Clément; Delavaux, Jean-Marc

2018-05-01

We report the design, experimental performance, and simulation of a single stage, co- and counter-pumped Tm-doped fiber amplifier (TDFA) in the 2 μm signal wavelength band with an optimized 1567 nm shared pump source. We investigate the dependence of output power, gain, and efficiency on pump coupling ratio and signal wavelength. Small signal gains of >50 dB, an output power of 2 W, and small signal noise figures of performance agree well with the experimental data. We also discuss performance tradeoffs with respect to amplifier topology for this simple and efficient TDFA.

Therapy with granulocyte colony-stimulating factor in the chronic stage, but not in the acute stage, improves experimental autoimmune myocarditis in rats via nitric oxide.

Science.gov (United States)

Shimada, Kana; Okabe, Taka-aki; Mikami, Yu; Hattori, Miki; Fujita, Masatoshi; Kishimoto, Chiharu

2010-09-01

We systematically investigated serial efficacy of granulocyte colony-stimulating factor (G-CSF) therapy upon experimental autoimmune myocarditis (EAM) in rats treated with and without the inhibition of nitric oxide (NO) with the analyses of tissue regeneration. G-CSF could mobilize multipotent progenitor cells of bone marrow into the peripheral blood and may improve ventricular function. A rat model of porcine myosin-induced EAM was used. After the immunization of myosin, G-CSF (10 microg/kg/day) or saline was injected intraperitoneally on days 0-21 in experiment 1 and on days 21-42 in experiment 2. Additional myosin-immunized rats were orally given 25 mg/kg/day of N(G)-nitro-L-arginine methylester (L-NAME), an inhibitor of nitric oxide synthase (NOS), in each experiment (each group; n=8-21). Serum cytokines and peripheral blood cell counts were measured in each group. In experiment 1, G-CSF treatment aggravated cardiac pathology associated with increased macrophage inflammatory protein-2 (MIP-2) and interleukin-6 (IL-6) levels and enhanced superoxide production. In experiment 2, G-CSF treatment reduced the severity of myocarditis with increased capillary density and improved left ventricular ejection fraction. In the rats with EAM treated with G-CSF associated with oral L-NAME treatment in experiment 2, the severity of myocarditis was not reduced. Myocardial c-kit(+) cells were demonstrated only in G-CSF-treated group in experiment 2 but not in other groups. G-CSF has differential effects on EAM in rats associated with the modulation of cytokine network. The overwhelming superoxide production by G-CSF administration in the acute stage may worsen the disease. G-CSF therapy improved cardiac function via NO system in a rat model of myocarditis in the chronic stage, but not in the acute stage, possibly through the myocardial regeneration and acceleration of healing process. Copyright 2010 Elsevier Ltd. All rights reserved.

Bagheera: A new experimental facility at Cea / Valduc for actinides studies under high dynamic loading

International Nuclear Information System (INIS)

Roy, G.; Llorca, F.; Lanier, G.; Lamalle, S.; Beaulieu, J.; Antoine, P.; Martinuzzi, P.

2006-01-01

This paper is a technical presentation about a new experimental facility recently developed at CEA/Valduc, BAGHEERA, a French acronym for 'Hopkinson And High Speed Experiments Glove Box'. This facility is used since mid-2003 to characterize the physical and mechanical behaviour of actinides under high dynamic loadings. For this purpose, four basic experimental devices are confined inside a single 10 m long, 3 m high and 1.5 m large glove box: a 50 mm bore diameter single stage light gas gun, two compression and torsion split Hopkinson bars (SHPB and TSHB respectively) and a Taylor test device (TTD). A unique highly automated system drives all devices. The overall architecture of the facility takes into account the useful ability to carry out symmetrical and reverse experiments with the gas gun, that is actinide to actinide impact and actinide to inert material impact. Design and technical data on the experimental equipment are addressed, with a particular emphasis on the gas gun specific features due to actinide applications

Fibrosis-Related Gene Expression in Single Ventricle Heart Disease.

Science.gov (United States)

Nakano, Stephanie J; Siomos, Austine K; Garcia, Anastacia M; Nguyen, Hieu; SooHoo, Megan; Galambos, Csaba; Nunley, Karin; Stauffer, Brian L; Sucharov, Carmen C; Miyamoto, Shelley D

2017-12-01

To evaluate fibrosis and fibrosis-related gene expression in the myocardium of pediatric subjects with single ventricle with right ventricular failure. Real-time quantitative polymerase chain reaction was performed on explanted right ventricular myocardium of pediatric subjects with single ventricle disease and controls with nonfailing heart disease. Subjects were divided into 3 groups: single ventricle failing (right ventricular failure before or after stage I palliation), single ventricle nonfailing (infants listed for primary transplantation with normal right ventricular function), and stage III (Fontan or right ventricular failure after stage III). To evaluate subjects of similar age and right ventricular volume loading, single ventricle disease with failure was compared with single ventricle without failure and stage III was compared with nonfailing right ventricular disease. Histologic fibrosis was assessed in all hearts. Mann-Whitney tests were performed to identify differences in gene expression. Collagen (Col1α, Col3) expression is decreased in single ventricle congenital heart disease with failure compared with nonfailing single ventricle congenital heart disease (P = .019 and P = .035, respectively), and is equivalent in stage III compared with nonfailing right ventricular heart disease. Tissue inhibitors of metalloproteinase (TIMP-1, TIMP-3, and TIMP-4) are downregulated in stage III compared with nonfailing right ventricular heart disease (P = .0047, P = .013 and P = .013, respectively). Matrix metalloproteinases (MMP-2, MMP-9) are similar between nonfailing single ventricular heart disease and failing single ventricular heart disease, and between stage III heart disease and nonfailing right ventricular heart disease. There is no difference in the prevalence of right ventricular fibrosis by histology in subjects with single ventricular failure heart disease with right ventricular failure (18%) compared with those with normal right

Staged regenerative sorption heat pump

Science.gov (United States)

Jones, Jack A. (Inventor)

1995-01-01

A regenerative adsorbent heat pump process and system for cooling and heating a space. A sorbent is confined in a plurality of compressors of which at least four are first stage and at least four are second stage. The first stage operates over a first pressure region and the second stage over a second pressure region which is higher than the first. Sorbate from the first stage enters the second stage. The sorbate loop includes a condenser, expansion valve, evaporator and the compressors. A single sorbate loop can be employed for single-temperature-control such as air conditioning and heating. Two sorbate loops can be used for two-temperature-control as in a refrigerator and freezer. The evaporator temperatures control the freezer and refrigerator temperatures. Alternatively the refrigerator temperature can be cooled by the freezer with one sorbate loop. A heat transfer fluid is circulated in a closed loop which includes a radiator and the compressors. Low temperature heat is exhausted by the radiator. High temperature heat is added to the heat transfer fluid entering the compressors which are desorbing vapor. Heat is transferred from compressors which are sorbing vapor to the heat transfer fluid, and from the heat transfer fluid to the compressors which are desorbing vapor. Each compressor is subjected to the following phases, heating to its highest temperature, cooling down from its highest temperature, cooling to its lowest temperature, and warming up from its lowest temperature. The phases are repeated to complete a cycle and regenerate heat.

Orifice Mass Flow Calculation in NASA's W-8 Single Stage Axial Compressor Facility

Science.gov (United States)

Bozak, Richard F.

2018-01-01

Updates to the orifice mass flow calculation for the W-8 Single Stage Axial Compressor Facility at NASA Glenn Research Center are provided to include the effect of humidity and incorporate ISO 5167. A methodology for including the effect of humidity into the inlet orifice mass flow calculation is provided. Orifice mass flow calculations provided by ASME PTC-19.5-2004, ASME MFC-3M-2004, ASME Fluid Meters, and ISO 5167 are compared for W-8's atmospheric inlet orifice plate. Differences in expansion factor and discharge coefficient given by these standards give a variation of about +/- 75% mass flow except for a few cases. A comparison of the calculations with an inlet static pressure mass flow correlation and a fan exit mass flow integration using test data from a 2017 turbofan rotor test in W-8 show good agreement between the inlet static pressure mass flow correlation, ISO 5167, and ASME Fluid Meters. While W-8's atmospheric inlet orifice plate violates the pipe diameter limit defined by each of the standards, the ISO 5167 is chosen to be the primary orifice mass flow calculation to use in the W-8 facility.

Solvent Carryover Characterization and Recovery for a 10-inch Single Stage Centrifugal Contactor

International Nuclear Information System (INIS)

Lentsch, R.D.; Stephens, A.B.; Leung, D.T.; Baffling, K.E.; Harmon, H.D.; Suggs, P.C.

2006-01-01

A test program has been performed to characterize the organic solvent carryover and recovery from centrifugal contactors in the Caustic-side Solvent Extraction (CSSX) process. CSSX is the baseline design for removing cesium from salt solutions for Department of Energy (DOE) Savannah River Site's Salt Waste Processing Facility. CSSX uses a custom solvent to extract cesium from the salt solution in a series of single stage centrifugal contactors. Meeting the Waste Acceptance Criteria at the Defense Waste Processing Facility and Saltstone, as well as plant economics, dictate that solvent loss should be kept to a minimum. Solvent droplet size distribution in the aqueous outlet streams of the CSSX contactors is of particular importance to the design of solvent recovery equipment. Because insufficient solvent droplet size data existed to form a basis for the recovery system design, DOE funded the CSSX Solvent Carryover Characterization and Recovery Test (SCCRT). This paper presents the droplet size distribution of solvent and concentration in the contactor aqueous outlet streams as a function of rotor speed, bottom plate type, and flow rate. It also presents the performance data of a prototype coalescer. (authors)

Intensity profiles behind a five-stage neutron interferometer

International Nuclear Information System (INIS)

Kischko, U.

1983-01-01

By means of the quantitative photography intensity profiles behind a five-stage ideal-crystal neutron interferometer at the thermal channel H25 of the high-flux reactor at the institute Laue-Langevin in Grenoble/France were dermined and compared with theoretical profiles. Contravily to X-rays by neutrons the hole Borrmann range is excited. This leads in the interference picture to superposition of several wave field components. It was shown that the spherical wave theory, as it was developed by W. Bauspiess, U. Bonse, and W. Graeff for the absorption-free neutron interferometer, describes well quantitatively the experimental intensity profiles. Expecially for the t-2t-t geometry the theoretically predicted focusing was confirmed. For the H-beam the intensity profile is symmetric and spatially limited; the O-beam is asymetric with intensities decreasing slowly up to the boundary. Geometrical differences within single stages lead to unique changes in the intensity profile. The pigtail pattern leading in the past to some puzzle guessing could be explained by the influence of geometrical defocusings on the phase shift. Important conclusions for the geometrical tolerances, which have to be regarded in the construction of neutron interferometers, could be obtained. (orig.) [de

SSTO RLVs: More Global Reach? A Study of the Use of Single Stage to Orbit Reusable Launch Vehicles as Airlift Platforms.

Science.gov (United States)

1996-11-01

Orbit ( SSTO ) Reusable Launch Vehicles (RLVs) are currently under cooperative development by NASA, the Air Force, and the aerospace industry in the pursuit...exploit these rapid transit technologies to advance ’Global Reach for America.’ The SSTO RLV is a single stage rocket that will be completely reusable...investigated to assess the projected capabilities and costs of the SSTO system. This paper reviews the proposed capabilities of the SSTO system, discusses

Single-phase and two phase bubbly flow in a T connection: theoretical and experimental study

International Nuclear Information System (INIS)

Hervieu, Eric

1988-01-01

The objective of this research thesis is to highlight the driving factors of the separation of phases of a bubbly flow in a T junction, and to develop a prediction model. In a first part, the author reports the rigorous formulation of equations averaged on the T volume. He shows that it's not possible to solve globally the problem with these equations. Then, he reports a bibliographical study on the modelling of a bubbly flow, and, based upon this study, highlights intrinsic characteristics of the flow, and explains its dynamic mechanisms. He reports the development of the theoretical model, and describes the experimental installation used to validate it. In the third part, he reports the study of the liquid-gas interaction, and presents the adopted approach: study of the behaviour of an isolated bubble within a single-phase flow. Experimentation is used to check theoretical predictions. Results are used to compute phase separation. The obtained results are again compared with experimental results to validate the global relevance of the model [fr

Experimental investigations of single and two-phase flow in a heated rod bundle

International Nuclear Information System (INIS)

Barthel, Frank; Franz, Ronald; Hampel, Uwe; Technische Univ. Dresden

2013-01-01

An experimental facility for the study of boiling flows in a 3 x 3 rod bundle geometry was setup. The bundle resembles in essential geometrical parts the geometry in a pressurized water reactor fuel element. The facility is operated with a refrigerant fluid. Beside standard instrumentation for temperature, pressure and flow rate we employed particle image velocimetry for single phase flow studies, gamma ray densitometry for integral gas fraction measurement sand ultrafast X-ray tomography for the study of the void dynamics in the cross-section. Moreover extensive thermo-instrumentation allows axial rod surface temperature measurements for the central heated rod. First results will be discussed in this article. (orig.)

Effects of low-level laser therapy (LLLT) and diclofenac (topical and intramuscular) as single and combined therapy in experimental model of controlled muscle strain in rats.

Science.gov (United States)

de Paiva Carvalho, Rodrigo Leal; Leal-Junior, Ernesto Cesar Pinto; Petrellis, Maria Carla; Marcos, Rodrigo Labat; de Carvalho, Maria Helena Catelli; De Nucci, Gilberto; Lopes-Martins, Rodrigo Alvaro Brandão

2013-01-01

Muscle injuries represent ca 30% of sports injuries and excessive stretching of muscle causes more than 90% of injuries. Currently the most used treatments are nonsteroidal anti-inflammatory drugs (NSAIDs), however, in last years, low-level laser therapy (LLLT) is becoming an interesting therapeutic modality. The aim of this study was to evaluate the effect of single and combined therapies (LLLT, topical application of diclofenac and intramuscular diclofenac) on functional and biochemical aspects in an experimental model of controlled muscle strain in rats. Muscle strain was induced by overloading tibialis anterior muscle of rats. Injured groups received either no treatment, or a single treatment with topical or intramuscular diclofenac (TD and ID), or LLLT (3 J, 810 nm, 100 mW) 1 h after injury. Walking track analysis was the functional outcome and biochemical analyses included mRNA expression of COX-1 and COX-2 and blood levels of prostaglandin E2 (PGE2 ). All treatments significantly decreased COX-1 and COX-2 gene expression compared with injury group (P levels and walking track analysis (P topical and intramuscular diclofenac in treatment of muscle strain injury in acute stage. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

A six-degree-of-freedom magnetic levitation fine stage for a high-precision and high-acceleration dual-servo stage

International Nuclear Information System (INIS)

Kim, MyeongHyeon; Jeong, Jae-heon; Gweon, DaeGab; Kim, HyoYoung

2015-01-01

This paper presents a novel six-degree-of-freedom magnetic levitation fine stage for a dual-servo stage. The proposed fine stage is levitated and actuated, using a voice coil motor actuator with a Halbach magnet array. For a dual-servo stage, fine stage performance is deeply intertwined with coarse stage performance. Because the fine stage is installed over the coarse stage, the overall size of the fine stage can be limited by the moving plate of the coarse stage. Therefore, magnetic flux modeling and optimization are performed to manufacture optimal fine stages. To control the fine stage, actuator kinetics and sensor kinematics are proposed. Homing control is implemented by using linear variable differential transformers, whereas fine control is implemented by capacitance sensors and laser interferometers. Finally, experimental results of in-position stability, moving range, and repeatability are presented. (paper)

CFD simulations of compressed air two stage rotary Wankel expander – Parametric analysis

International Nuclear Information System (INIS)

Sadiq, Ghada A.; Tozer, Gavin; Al-Dadah, Raya; Mahmoud, Saad

2017-01-01

Highlights: • CFD ANSYS-Fluent 3D simulation of Wankel expander is developed. • Single and two-stage expander’s performance is compared. • Inlet and outlet ports shape and configurations are investigated. • Isentropic efficiency of two stage Wankel expander of 91% is achieved. - Abstract: A small scale volumetric Wankel expander is a powerful device for small-scale power generation in compressed air energy storage (CAES) systems and Organic Rankine cycles powered by different heat sources such as, biomass, low temperature geothermal, solar and waste heat leading to significant reduction in CO_2 emissions. Wankel expanders outperform other types of expander due to their ability to produce two power pulses per revolution per chamber additional to higher compactness, lower noise and vibration and lower cost. In this paper, a computational fluid dynamics (CFD) model was developed using ANSYS 16.2 to simulate the flow dynamics for a single and two stage Wankel expanders and to investigate the effect of port configurations, including size and spacing, on the expander’s power output and isentropic efficiency. Also, single-stage and two-stage expanders were analysed with different operating conditions. Single-stage 3D CFD results were compared to published work showing close agreement. The CFD modelling was used to investigate the performance of the rotary device using air as an ideal gas with various port diameters ranging from 15 mm to 50 mm; port spacing varying from 28 mm to 66 mm; different Wankel expander sizes (r = 48, e = 6.6, b = 32) mm and (r = 58, e = 8, b = 40) mm both as single-stage and as two-stage expanders with different configurations and various operating conditions. Results showed that the best Wankel expander design for a single-stage was (r = 48, e = 6.6, b = 32) mm, with the port diameters 20 mm and port spacing equal to 50 mm. Moreover, combining two Wankel expanders horizontally, with a larger one at front, produced 8.52 kW compared

Kinetics of two-stage fermentation process for the production of hydrogen

Energy Technology Data Exchange (ETDEWEB)

Nath, Kaushik [Department of Chemical Engineering, G.H. Patel College of Engineering and Technology, Vallabh Vidyanagar 388 120, Gujarat (India); Muthukumar, Manoj; Kumar, Anish; Das, Debabrata [Fermentation Technology Laboratory, Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302 (India)

2008-02-15

Two-stage process described in the present work is a combination of dark and photofermentation in a sequential batch mode. In the first stage glucose is fermented to acetate, CO{sub 2} and H{sub 2} in an anaerobic dark fermentation by Enterobacter cloacae DM11. This is followed by a successive second stage where acetate is converted to H{sub 2} and CO{sub 2} in a photobioreactor by photosynthetic bacteria, Rhodobacter sphaeroides O.U. 001. The yield of hydrogen in the first stage was about 3.31molH{sub 2}(molglucose){sup -1} (approximately 82% of theoretical) and that in the second stage was about 1.5-1.72molH{sub 2}(molaceticacid){sup -1} (approximately 37-43% of theoretical). The overall yield of hydrogen in two-stage process considering glucose as preliminary substrate was found to be higher compared to a single stage process. Monod model, with incorporation of substrate inhibition term, has been used to determine the growth kinetic parameters for the first stage. The values of maximum specific growth rate ({mu} {sub max}) and K{sub s} (saturation constant) were 0.398h{sup -1} and 5.509gl{sup -1}, respectively, using glucose as substrate. The experimental substrate and biomass concentration profiles have good resemblance with those obtained by kinetic model predictions. A model based on logistic equation has been developed to describe the growth of R. sphaeroides O.U 001 in the second stage. Modified Gompertz equation was applied to estimate the hydrogen production potential, rate and lag phase time in a batch process for various initial concentration of glucose, based on the cumulative hydrogen production curves. Both the curve fitting and statistical analysis showed that the equation was suitable to describe the progress of cumulative hydrogen production. (author)

Separate-stage fermentation of biomass to methane

Energy Technology Data Exchange (ETDEWEB)

Clausen, E C; Gaddy, J L

1978-01-01

The production of CH/sub 4/ from orchard grass by anaerobic fermentation was separated into three stages and the kinetics and economics of the process were evaluated. The first stage was acid hydrolysis of the grass polysaccharides, the second stage was acid and alcohol formation from the sugars with a mixed sewage culture, and the third was CH/sub 4/ formation, also with enriched sewage cultures, from the effluent from the second stage reactor. Separating the steps showed a significant increase in CH/sub 4/ production per g of grass, but was less economical than a single-stage process.

One stage revision single-bundle anterior cruciate ligament reconstruction with impacted morselized bone graft following a failed double-bundle reconstruction

Directory of Open Access Journals (Sweden)

Ho Jong Ra

2017-01-01

Full Text Available Although double-bundle anterior cruciate ligament (ACL reconstruction has theoretical benefits such as more accurate reproduction of ACL anatomy, it is technically more demanding surgery. This report describes the case of a one stage revision single-bundle ACL reconstruction after primary double-bundle ACL reconstruction. A professional dancer had an ACL previously reconstructed with a double-bundle technique, but the femoral tunnels were malpositioned resulting in residual laxity and rotational instability. The previous femoral tunnel positions were vertical and widened. The previous vertical tunnels were filled with impacted bone graft and a revision single-bundle ACL reconstruction was performed via the new femoral tunnel with a 2 O'clock position between the previous two tunnels. After 10 months of postoperative rehabilitation, the patient returned to professional dancing with sound bony union and without any residual instability.

Low energy single-staged anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for wastewater treatment.

Science.gov (United States)

Aslam, Muhammad; McCarty, Perry L; Shin, Chungheon; Bae, Jaeho; Kim, Jeonghwan

2017-09-01

An aluminum dioxide (Al 2 O 3 ) ceramic membrane was used in a single-stage anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for low-strength wastewater treatment. The AFCMBR was operated continuously for 395days at 25°C using a synthetic wastewater having a chemical oxygen demand (COD) averaging 260mg/L. A membrane net flux as high as 14.5-17L/m 2 h was achieved with only periodic maintenance cleaning, obtained by adding 25mg/L of sodium hypochlorite solution. No adverse effect of the maintenance cleaning on organic removal was observed. An average SCOD in the membrane permeate of 23mg/L was achieved with a 1h hydraulic retention time (HRT). Biosolids production averaged 0.014±0.007gVSS/gCOD removed. The estimated electrical energy required to operate the AFCMBR system was 0.039kWh/m 3 , which is only about 17% of the electrical energy that could be generated with the methane produced. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of a single stage inverter with one cycle control for photovoltaic power generation

Energy Technology Data Exchange (ETDEWEB)

Egiziano, L.; Femia, N.; Granozio, D.; Petrone, G.; Spagnuolo, G. [Salermo Univ., Salermo (Italy); Vitelli, M. [Seconda Univ. di Napoli, Napoli (Italy)

2006-07-01

An optimized one-cycle control (OCC) for maximum power point tracking and power factor correction in grid-connected photovoltaic (PV) applications was described. OCC is a nonlinear control technique that rejects line perturbations and allows both output power factor co-reaction and tracking of input PV fields. An OCC system was analyzed in order to select optimal design parameters. Parameters were refined through the selection of suitable design constraints. A stochastic search was then performed. Criteria were then developed to distinguish appropriate design parameters for the optimized OCC. The optimization was based on advanced heuristic techniques for non-linear constrained optimization. Performance indices were calculated for each feasible set of parameters. A customized perturb and observe control was then applied to the single-stage inverter. Results of the optimization process were validated by a series of time-domain simulations conducted under heavy, varying irradiance conditions. Results of the simulations showed that the optimized controllers showed improved performance in terms of power drawn from the PV field. 7 refs., 1 tab., 5 figs.

Attainability and minimum energy of multiple-stage cascade membrane Systems

KAUST Repository

Alshehri, Ali

2015-08-12

Process design and simulation of multi-stage membrane systems have been widely studied in many gas separation systems. However, general guidelines have not been developed yet for the attainability and the minimum energy consumption of a multi-stage membrane system. Such information is important for conceptual process design and thus it is the topic of this work. Using a well-mixed membrane model, it was determined that the attainability curve of multi-stage systems is defined by the pressure ratio and membrane selectivity. Using the constant recycle ratio scheme, the recycle ratio can shift the attainability behavior between single-stage and multi-stage membrane systems. When the recycle ratio is zero, all of the multi-stage membrane processes will decay to a single-stage membrane process. When the recycle ratio approaches infinity, the required selectivity and pressure ratio reach their absolute minimum values, which have a simple relationship with that of a single-stage membrane process, as follows: View the MathML sourceSn=S1, View the MathML sourceγn=γ1, where n is the number of stages. The minimum energy consumption of a multi-stage membrane process is primarily determined by the membrane selectivity and recycle ratio. A low recycle ratio can significantly reduce the required membrane selectivity without substantial energy penalty. The energy envelope curve can provide a guideline from an energy perspective to determine the minimum required membrane selectivity in membrane process designs to compete with conventional separation processes, such as distillation.

Studies on water turbine runner which fish can pass through: In case of single stage axial runner

International Nuclear Information System (INIS)

Shimizu, Yukimari; Maeda, Takao; Nagoshi, Osamu; Ieda, Kazuma; Shinma, Hisako; Hagimoto, Michiko

1994-01-01

The relationship between water turbine runner design and operation and the safe passage of fish through the turbine is studied. The kinds of fish used in the tests are a dace, a sweet fish and a small salmon. A single stage axial runner is used. The velocity and pressure distributions were measured inside the turbine casing and along the casing wall. Many pictures showing fish passing through the rotating runner were taken and analyzed. The swimming speed of the fish was examined from video recordings. Fish pass through the runner more rapidly when they can determine and choose the easier path. Injury and mortality of fish are affected by the runner speed and the location of impact of the runner on the fish body

Computed tomography in dementia of Alzheimer type; Comparative study in each stage and comparison to single photon emission computed tomography with N-isopropyl-p-( sup 123 I) iodoamphetamine

Energy Technology Data Exchange (ETDEWEB)

Tsunoda, Masahiko; Fujii, Tsutomu; Tanii, Yasuyuki [Toyama Medical and Pharmaceutical Univ., Toyama (Japan); and others

1990-05-01

Computed tomography (CT) examinations of 7 patients with dementia of Alzheimer type were reviewed and correlated with clinical stages. The findings of CT were also compared with those of single photon emission computed tomography (SPECT). There was no positive correlation between the degree of cerebral atrophy on CT and clinical stage. Cerebral atrophy seemed to be influenced by aging, ill duration, and the degree of dementia. The cerebral/cerebellar uptake ratio of RI on SPECT was significantly decreased with the progression of clinical stage. SPECT seemed to reflect the degree of dementia, irrespective of ages and ill duration. (N.K.).

A silicon integrated micro nano-positioning XY-stage for nano-manipulation

International Nuclear Information System (INIS)

Sun Lining; Wang Jiachou; Rong Weibin; Li Xinxin; Bao Haifei

2008-01-01

An integrated micro XY-stage with a 2 × 2 mm 2 movable table is designed and fabricated for application in nanometer-scale operation and nanometric positioning precision. The device integrates the functions of both actuating and sensing in a monolithic chip and is mainly composed of a silicon-based XY-stage, comb-drive actuator and a displacement sensor, which are developed by using double-sided bulk-micromachining technology. The high-aspect-ratio comb-driven XY-stage is achieved by deep reactive ion etching (DRIE) on both sides of the wafer. The displacement sensor is formed on four vertical sidewall surface piezoresistors with a full Wheatstone bridge circuit, where a novel fabrication process of a vertical sidewall surface piezoresistor is proposed. Comprehensive design and analysis of the comb actuator, the piezoresistive displacement sensor and the XY-stage are given in full detail, and the experimental results verify the design and fabrication of the device. The final realization of the device shows that the sensitivity of the fabricated piezoresistive sensors is better than 1.17 mV µm −1 without amplification, and the linearity is better than 0.814%. Under 28.5 V driving voltage, a ±10 µm single-axis displacement is measured without crosstalk and the resonant frequency is measured at 983 Hz in air

A Robust High-Performance GPS L1 Receiver with Single-stage Quadrature Redio-Frequency Circuit

Science.gov (United States)

Liu, Jianghua; Xu, Weilin; Wan, Qinq; Liu, Tianci

2018-03-01

A low power current reuse single-stage quadrature raido-frequency part (SQRF) is proposed for GPS L1 receiver in 180nm CMOS process. The proposed circuit consists of LNA, Mixer, QVCO, is called the QLMV cell. A two blocks stacked topology is adopted in this design. The parallel QVCO and mixer placed on the top forms the upper stacked block, and the LNA placed on the bottom forms the other stacked block. The two blocks share the current and achieve low power performance. To improve the stability, a float current source is proposed. The float current isolated the local oscillation signal and the input RF signal, which bring the whole circuit robust high-performance. The result shows conversion gain is 34 dB, noise figure is three dB, the phase noise is -110 dBc/Hz at 1MHz and IIP3 is -20 dBm. The proposed circuit dissipated 1.7mW with 1 V supply voltage.

One-stage or multi-stage creep fatigue behaviour of heat-resistant steels

International Nuclear Information System (INIS)

Kloos, K.H.; Granacher, J.; Scholz, A.

1994-01-01

For one stage realistic long term alternating strain tests on two forged steels with the duration of tests up to an order of magnitude of 45,000 hours, the generalised damage accumulation rule, using an optimised evaluation process dealing with pre-stress effects leads to a relative creep fatigue service life of one. A replacement description by the modified service life share rule is indicated for the long term area. First results from realistic three step tests are classified in the scatter band of single stage stress, where there are only slight differences from different cycle counting processes. (orig.) [de

Theoretical and experimental investigation on internal reflectors in a single-slope solar still

International Nuclear Information System (INIS)

Karimi Estahbanati, M.R.; Ahsan, Amimul; Feilizadeh, Mehrzad; Jafarpur, Khosrow; Ashrafmansouri, Seyedeh-Saba; Feilizadeh, Mansoor

2016-01-01

Highlights: • The effect of installing an internal reflector in solar stills is investigated. • A mathematical model is presented which takes into account the effect of all walls. • The model is validated with the experimental data. • The internal reflector can increase yearly distillate production by 34%. • Cloud factor significantly decreases the effect of internal reflector. - Abstract: This study investigated the effect of an internal reflector (IR) on the productivity of a single-slope solar still (during the summer and winter) experimentally and theoretically. A mathematical model was presented which took into account the effect of all walls (north, south, west and east) of the still on the amount of received solar radiation to brine, and the model was validated with the experimental data. The model can calculate the yield of the still with and without IR on various walls. The results show that the simultaneous use of IR on front and side walls enhances the still’s efficiency by 18%. However, installation of an IR on the back wall can increase the annual efficiency by 22%. The installation of IRs on all walls in comparison to a still without IR can increase the distillate production at winter, summer and the entire year by 65%, 22% and 34%, respectively. Furthermore, the effect of cloud factor on the installation of IRs on all walls was examined, and the results indicate that the increasing the cloud factor decreases the influence of IRs significantly.

Brain single-photon emission tomography with technetium-99m hexamethylpropylene amine oxime in adolscents with intial-stage schizophrenia

International Nuclear Information System (INIS)

Batista, J.F.; Galiano, M.C.; Torres, L.A.; Hernandez, M.C.; Sosa, F.; Perera, A.; Perez, M.

1995-01-01

The objective of this study was to search for regional cerebral blood flow (rCBF) abnormalities in adolescents with initial-stage schizophrenia by means of brain single-photon emission tomography (SPET) using technetium-99m hexamethylpropylene amine oxime (HMPAO). SPET studies were performed on a homogeneous sample of 15 carefully selected adolescents with a recent diagnosis of schizophrenia, and without previous electroconvulsive or antipsychotic drug treatment. Computed tomography (CT) and electro-encephalographic (EEG) studies were performed in all patients. Qualitative and semiquantitative analysis of 99m Tc-HMPAO SPET studies showed an impaired rCBF in 12 patients (80%). The most common pattern was a decreased uptake of 99m Tc-HMPAO in the frontal lobes, usually in the left hemisphere. Conventional and quantitative EEG was positive in 12 (80%) and 15 (100%) patients, respectively. CT findings were positive in two patients (13%). There was a high level of concordance between SPET and EEG results and between SPET and clinical features (P > 0.05). This study suggests that previously untreated patients in the first stages of schizophrenia present functional abnormalities that are revealed by brain SPET. (orig.)

Changes in blood flow during one stage lengthening of bone: an experimental study in rats.

Science.gov (United States)

Kwon, S T; Chung, C Y

2000-06-01

Distraction osteogenesis is a well-accepted method of bone lengthening. Its disadvantages, however, are that it requires an external fixator and takes a long time. One-stage lengthening therefore offers certain advantages. A first point of reference for the safe limits of this procedure might be the changes of blood flow, and this is also the crucial factor in deciding on the appropriate method of lengthening, particularly where the hand or foot is involved. Using a laser Doppler flowmeter we measured blood flow in the dorsum of the foot after using bilateral minimonofixators to lengthen the tibias of 15 Sprague-Dawley rats. They were lengthened in four stages: stage 0 (before lengthening); stage I--12.5%; stage II--25%; and stage III--31.25% of lengthening. The blood flow during stage I decreased to 79% compared to that of stage 0; 16% during stage II; and 1% during stage III. This study suggests that the maximal permissible extent of lengthening might be less than a quarter according to the blood flow as suggested by this animal model.

Opposed piston linear compressor driven two-stage Stirling Cryocooler for cooling of IR sensors in space application

Science.gov (United States)

Bhojwani, Virendra; Inamdar, Asif; Lele, Mandar; Tendolkar, Mandar; Atrey, Milind; Bapat, Shridhar; Narayankhedkar, Kisan

2017-04-01

A two-stage Stirling Cryocooler has been developed and tested for cooling IR sensors in space application. The concept uses an opposed piston linear compressor to drive the two-stage Stirling expander. The configuration used a moving coil linear motor for the compressor as well as for the expander unit. Electrical phase difference of 80 degrees was maintained between the voltage waveforms supplied to the compressor motor and expander motor. The piston and displacer surface were coated with Rulon an anti-friction material to ensure oil less operation of the unit. The present article discusses analysis results, features of the cryocooler and experimental tests conducted on the developed unit. The two-stages of Cryo-cylinder and the expander units were manufactured from a single piece to ensure precise alignment between the two-stages. Flexure bearings were used to suspend the piston and displacer about its mean position. The objective of the work was to develop a two-stage Stirling cryocooler with 2 W at 120 K and 0.5 W at 60 K cooling capacity for the two-stages and input power of less than 120 W. The Cryocooler achieved a minimum temperature of 40.7 K at stage 2.

A method for determining optimum phasing of a multiphase propulsion system for a single-stage vehicle with linearized inert weight

Science.gov (United States)

Martin, J. A.

1974-01-01

A general analytical treatment is presented of a single-stage vehicle with multiple propulsion phases. A closed-form solution for the cost and for the performance and a derivation of the optimal phasing of the propulsion are included. Linearized variations in the inert weight elements are included, and the function to be minimized can be selected. The derivation of optimal phasing results in a set of nonlinear algebraic equations for optimal fuel volumes, for which a solution method is outlined. Three specific example cases are analyzed: minimum gross lift-off weight, minimum inert weight, and a minimized general function for a two-phase vehicle. The results for the two-phase vehicle are applied to the dual-fuel rocket. Comparisons with single-fuel vehicles indicate that dual-fuel vehicles can have lower inert weight either by development of a dual-fuel engine or by parallel burning of separate engines from lift-off.

Single-Molecule Force Spectroscopy Trajectories of a Single Protein and Its Polyproteins Are Equivalent: A Direct Experimental Validation Based on A Small Protein NuG2.

Science.gov (United States)

Lei, Hai; He, Chengzhi; Hu, Chunguang; Li, Jinliang; Hu, Xiaodong; Hu, Xiaotang; Li, Hongbin

2017-05-22

Single-molecule force spectroscopy (SMFS) has become a powerful tool in investigating the mechanical unfolding/folding of proteins at the single-molecule level. Polyproteins made of tandem identical repeats have been widely used in atomic force microscopy (AFM)-based SMFS studies, where polyproteins not only serve as fingerprints to identify single-molecule stretching events, but may also improve statistics of data collection. However, the inherent assumption of such experiments is that all the domains in the polyprotein are equivalent and one SMFS trajectory of stretching a polyprotein made of n domains is equivalent to n trajectories of stretching a single domain. Such an assumption has not been validated experimentally. Using a small protein NuG2 and its polyprotein (NuG2) 4 as model systems, here we use optical trapping (OT) to directly validate this assumption. Our results show that OT experiments on NuG2 and (NuG2) 4 lead to identical parameters describing the unfolding and folding kinetics of NuG2, demonstrating that indeed stretching a polyprotein of NuG2 is equivalent to stretching single NuG2 in force spectroscopy experiments and thus validating the use of polyproteins in SMFS experiments. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Multidisciplinary Performance Analysis of a Lifting-Body Single-Stage-to-Orbit Vehicle

Science.gov (United States)

Tartabini, Paul V.; Lepsch, Roger A.; Korte, J. J.; Wurster, Kathryn E.

2000-01-01

Lockheed Martin Skunk Works (LMSW) is currently developing a single-stage-to-orbit reusable launch vehicle called VentureStar(TM) A team at NASA Langley Research Center participated with LMSW in the screening and evaluation of a number of early VentureStar(TM) configurations. The performance analyses that supported these initial studies were conducted to assess the effect of a lifting body shape, linear aerospike engine and metallic thermal protection system (TPS) on the weight and performance of the vehicle. These performance studies were performed in a multidisciplinary fashion that indirectly linked the trajectory optimization with weight estimation and aerothermal analysis tools. This approach was necessary to develop optimized ascent and entry trajectories that met all vehicle design constraints. Significant improvements in ascent performance were achieved when the vehicle flew a lifting trajectory and varied the engine mixture ratio during flight. Also, a considerable reduction in empty weight was possible by adjusting the total oxidizer-to-fuel and liftoff thrust-to-weight ratios. However, the optimal ascent flight profile had to be altered to ensure that the vehicle could be trimmed in pitch using only the flow diverting capability of the aerospike engine. Likewise, the optimal entry trajectory had to be tailored to meet TPS heating rate and transition constraints while satisfying a crossrange requirement.

A successful experimental observation of double-photon Compton scattering of γ rays using a single γ detector

International Nuclear Information System (INIS)

Saddi, M.B.; Sandhu, B.S.; Singh, B.

2006-01-01

The phenomenon of double-photon Compton scattering has been successfully observed using a single γ detector, a technique avoiding the use of the complicated slow-fast coincidence set-up used till now for observing this higher-order process. Here doubly differential collision cross-sections integrated over the directions of one of the two final photons, the direction of other one being kept fixed, are measured experimentally for 0.662 MeV incident γ photons. The energy spectra of the detected photons are observed as a long tail to the single-photon Compton line on the lower side of the full energy peak in the recorded scattered energy spectrum. The present results are in agreement with theory of this process

From a Single Presentation of Poetry Up to Its Stylized Stage Image in the Form of Theatre Performance

Directory of Open Access Journals (Sweden)

Podmaková Ú Dagmar

2017-06-01

Full Text Available In the 1940s the Drama Company of the Slovak National Theatre introduced four poetry productions, which demonstrated the stage potential of the symbiosis of verse and a music-accompanied recitation in an original stage design solution. The single presentation of poetry of Poézia revolúcie a boja [The Poetry of Revolution and Fight, 1945] directed by Ján Jamnický and Pásmo poézie Janka Jesenského [The Show of Poetry by Janko Jesenský, 1946] directed by Jozef Budský were the first independent attempts at staging selected poetry. Besides recitation, they were dominated by the visual sign, powerful music sometimes accompanied by the singing of individuals and a voice band, and distinctive lighting design. Botto’s Smrť Jánošíkova [The Death of Jánošík] and Sládkovič’s Marína (both in 1948 directed by Jozef Budský displayed all features of synthetic theatre, combining recitation, voice band singing, scenic and visual solutions, metaphor, originally composed music inspired by the folk song, dance, film screening, and meaningful lighting. Jozef Budský indirectly built on Czech theatre, particularly on E. F. Burian. Both masterpieces by the authors of Štúr’s generation (Ján Botto, Andrej Sládkovič aroused the interest of the expert public and the audience. It triggered arguments about excessive directorial intervention and insufficient ideological character, especially in the theatre form of Marína.

Stability management of high speed axial flow compressor stage through axial extensions of bend skewed casing treatment

Directory of Open Access Journals (Sweden)

DilipkumarBhanudasji Alone

2016-09-01

Full Text Available This paper presents the experimental results to understand the performance of moderately loaded high speed single stage transonic axial flow compressor subjected to various configurations of axial extensions of bend skewed casing treatment with moderate porosity. The bend skewed casing treatment of 33% porosity was coupled with rectangular plenum chamber of depth equal to the slots depth. The five axial extensions of 20%, 40%, 60%, 80% and 100% were used for the experimental evaluations of compressor performance. The main objective was to identify the optimum extension of the casing treatment with reference to rotor leading edge which results in maximum stall margin improvements with minimum loss in the stage efficiency. At each axial extension the compressor performance is distinctive. The improvement in the stall margin was very significant at some axial extensions with 4%–5% penalty in the stage efficiency. The compressors stage shows recovery in terms of efficiency at lower axial extensions of 20% and 40% with increase in the peak stage efficiency. Measurements of flow parameters showed the typical behaviors at near stall flow conditions. Hot wire sensor was placed at the rotor upstream in the tip region to capture the oscillations in the inlet axial and tangential velocities at stall conditions. In the absence of casing treatment the compressor exhibit abrupt stall with very high oscillations in the inlet axial and tangential velocity of the flow. The extents of oscillations reduce with bend skewed casing treatment. Few measurements were also performed in the plenum chamber and salient results are presented in this paper.

Two-stage precipitation of plutonium trifluoride

International Nuclear Information System (INIS)

Luerkens, D.W.

1984-04-01

Plutonium trifluoride was precipitated using a two-stage precipitation system. A series of precipitation experiments identified the significant process variables affecting precipitate characteristics. A mathematical precipitation model was developed which was based on the formation of plutonium fluoride complexes. The precipitation model relates all process variables, in a single equation, to a single parameter that can be used to control particle characteristics

Stages in learning motor synergies: a view based on the equilibrium-point hypothesis.

Science.gov (United States)

Latash, Mark L

2010-10-01

This review describes a novel view on stages in motor learning based on recent developments of the notion of synergies, the uncontrolled manifold hypothesis, and the equilibrium-point hypothesis (referent configuration) that allow to merge these notions into a single scheme of motor control. The principle of abundance and the principle of minimal final action form the foundation for analyses of natural motor actions performed by redundant sets of elements. Two main stages of motor learning are introduced corresponding to (1) discovery and strengthening of motor synergies stabilizing salient performance variable(s) and (2) their weakening when other aspects of motor performance are optimized. The first stage may be viewed as consisting of two steps, the elaboration of an adequate referent configuration trajectory and the elaboration of multi-joint (multi-muscle) synergies stabilizing the referent configuration trajectory. Both steps are expected to lead to more variance in the space of elemental variables that is compatible with a desired time profile of the salient performance variable ("good variability"). Adjusting control to other aspects of performance during the second stage (for example, esthetics, energy expenditure, time, fatigue, etc.) may lead to a drop in the "good variability". Experimental support for the suggested scheme is reviewed. Copyright © 2009 Elsevier B.V. All rights reserved.

Experimental study of CT perfusion in hepatitis, hepatic fibrosis and early stage of cirrhosis

International Nuclear Information System (INIS)

Guan Sheng; Zhao Weidong; Zhou Kangrong; Peng Weijun; Mao Jian; Tang Feng; Wang Yong; Cao Guang; Sun Fei

2005-01-01

Objective: To investigate the value of CT perfusion in the early diagnosis of hepatic diffuse disease. Methods: Fourteen male Wistar rats of control group and 14 of test group at stages of hepatitis, hepatic fibrosis, hepatic cirrhosis which were induced with diethylnitrosamine (DEN), were studied with CT perfusion respectively. CT perfusion data of different stages were compared and pathologic analysis were performed. Results: Density-time curves of CT perfusion were satisfactory and all perfusion data could be obtained. During the period of hepatitis developing into early stage of hepatic cirrhosis, hepatic artery flow (HAF) trended to increase in test group, mean transmit time (MTT) prolonged obviously, blood flow (BF) and volume (BV) declined. While in control group, HAF declined slightly, MTT, BV and BF increased. Statistic analysis showed the differences of HAF and MTT at different stages between control and test groups were significant (P<0.05 ); the differences of BV and BF between hepatitis and hepatic cirrhosis, hepatic fibrosis and early stage of hepatic cirrhosis in test group were significant (P<0.05), but no significant difference between hepatitis and hepatic fibrosis. The corresponding pathologic changes at stage of hepatitis was swelling of hepatic cells; sinusoids cap illarization and deposition of collagen in the extravascular Disse's spaces were the main changes relating to hepatic blood perfusion at stage of fibrosis and early stage of cirrhosis. Conclusion: The method of CT scan can reflect some changes of hepatic blood perfusion in rats with hepatitis, hepatic fibrosis and early stage of cirrhosis. The data of CT perfusion, especially the changes should be valuable for clinical early diagnosis, treatment and follow-up. (authors)

Evaluating statistical and clinical significance of intervention effects in single-case experimental designs: An SPSS method to analyze univariate data

NARCIS (Netherlands)

Maric, M.; de Haan, M.; Hogendoorn, S.M.; Wolters, L.H.; Huizenga, H.M.

2015-01-01

Single-case experimental designs are useful methods in clinical research practice to investigate individual client progress. Their proliferation might have been hampered by methodological challenges such as the difficulty applying existing statistical procedures. In this article, we describe a

Evaluating statistical and clinical significance of intervention effects in single-case experimental designs: an SPSS method to analyze univariate data

NARCIS (Netherlands)

Maric, Marija; de Haan, Else; Hogendoorn, Sanne M.; Wolters, Lidewij H.; Huizenga, Hilde M.

2015-01-01

Single-case experimental designs are useful methods in clinical research practice to investigate individual client progress. Their proliferation might have been hampered by methodological challenges such as the difficulty applying existing statistical procedures. In this article, we describe a

Correlation Between the Microstructural Defects and Residual Stress in a Single Crystal Nickel-Based Superalloy During Different Creep Stages

Science.gov (United States)

Mo, Fangjie; Wu, Erdong; Zhang, Changsheng; Wang, Hong; Zhong, Zhengye; Zhang, Jian; Chen, Bo; Hofmann, Michael; Gan, Weimin; Sun, Guangai

2018-03-01

The present work attempts to reveal the correlation between the microstructural defects and residual stress in the single crystal nickel-based superalloy, both of which play the significant role on properties and performance. Neutron diffraction was employed to investigate the microstructural defects and residual stresses in a single crystal (SC) nickel-based superalloy, which was subjected to creeping under 220 MPa and 1000 °C for different times. The measured superlattice and fundamental lattice reflections confirm that the mismatch and tetragonal distortions with c/a > 1 exist in the SC superalloy. At the initially unstrained state, there exists the angular distortion between γ and γ' phases with small triaxial compressive stresses, ensuring the structural stability of the superalloy. After creeping, the tetragonal distortion for the γ phase is larger than that for the γ' phase. With increasing the creeping time, the mismatch between γ and γ' phases increases to the maximum, then decreases gradually and finally remains unchanged. The macroscopic residual stress shows a similar behavior with the mismatch, indicating the correlation between them. Based on the model of shear and dislocations, the evolution of microstructural defects and residual stress are reasonably explained. The effect of shear is dominant at the primary creep stage, which greatly enlarges the mismatch and the residual stress. The dislocations weaken the effect of shear for the further creep stage, resulting in the decrease of the mismatch and relaxation of the residual stress. Those findings add some helpful understanding into the microstructure-performance relationship in the SC nickel-based superalloy, which might provide the insight to materials design and applications.

An experimental vital signs detection radar using low-IF heterodyne architecture and single-sideband transmission

DEFF Research Database (Denmark)

Jensen, Brian Sveistrup; Johansen, Tom Keinicke; Yan, Lei

2013-01-01

In this paper an experimental X-band radar system, called DTU-VISDAM, developed for the detection and monitoring of human vital signs is described. The DTU-VISDAM radar exploits a low intermediate frequency (IF) heterodyne RF front-end architecture and single-sideband (SSB) transmission for easier...... and more reliable extraction of the vital signs. The hardware implementation of the proposed low-IF RF front-end architecture and associated IF circuitry is discussed. Furthermore, the signal processing and calibration steps necessary to extract the vital signs information measured on a human subject...

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.

Evaporation of freely suspended single droplets: experimental, theoretical and computational simulations

International Nuclear Information System (INIS)

Hołyst, R; Litniewski, M; Jakubczyk, D; Kolwas, K; Kolwas, M; Kowalski, K; Migacz, S; Palesa, S; Zientara, M

2013-01-01

Evaporation is ubiquitous in nature. This process influences the climate, the formation of clouds, transpiration in plants, the survival of arctic organisms, the efficiency of car engines, the structure of dried materials and many other phenomena. Recent experiments discovered two novel mechanisms accompanying evaporation: temperature discontinuity at the liquid–vapour interface during evaporation and equilibration of pressures in the whole system during evaporation. None of these effects has been predicted previously by existing theories despite the fact that after 130 years of investigation the theory of evaporation was believed to be mature. These two effects call for reanalysis of existing experimental data and such is the goal of this review. In this article we analyse the experimental and the computational simulation data on the droplet evaporation of several different systems: water into its own vapour, water into the air, diethylene glycol into nitrogen and argon into its own vapour. We show that the temperature discontinuity at the liquid–vapour interface discovered by Fang and Ward (1999 Phys. Rev. E 59 417–28) is a rule rather than an exception. We show in computer simulations for a single-component system (argon) that this discontinuity is due to the constraint of momentum/pressure equilibrium during evaporation. For high vapour pressure the temperature is continuous across the liquid–vapour interface, while for small vapour pressures the temperature is discontinuous. The temperature jump at the interface is inversely proportional to the vapour density close to the interface. We have also found that all analysed data are described by the following equation: da/dt = P 1 /(a + P 2 ), where a is the radius of the evaporating droplet, t is time and P 1 and P 2 are two parameters. P 1 = −λΔT/(q eff ρ L ), where λ is the thermal conductivity coefficient in the vapour at the interface, ΔT is the temperature difference between the liquid droplet

Arrayed architectures for multi-stage Si-micromachined high-flow Knudsen pumps

International Nuclear Information System (INIS)

Qin, Yutao; An, Seungdo; Gianchandani, Yogesh B

2015-01-01

This paper reports an evaluation and a comparison of two architectures for implementing Si-micromachined high-flow Knudsen pumps. Knudsen pumps, which operate on the principle of thermal transpiration, have been shown to have great promise for micro-scale gas phase fluidic systems such as micro gas chromatographs. Simultaneously achieving both a high flow rate and adequate blocking pressure has been a persistent challenge, which is addressed in this work by combining multiple pumps in series and addressing the resulting challenges in thermal management. The basic building block is a Si-micromachined pump with  ≈100 000 parallel channels in a 4 mm  ×  6 mm footprint. In the primary approach, multiple pump stages are stacked vertically with interleaved Si-micromachined spacers. A stacked 4-stage Knudsen pump has a form factor of 10 mm  ×  8 mm  ×  6 mm. In an alternate approach, multiple stages are arranged in a planar array. The experimental results demonstrate multiplication of the output pressure head with the number of stages, while the flow rate is maintained. For example, a stacked 4-stage Knudsen pump with 8 W power operated at atmospheric pressure provided a blocking pressure of 0.255 kPa, which was 3.6  ×  of that provided by a single-stage pump with 2 W power; while both provided a  ≈  30 sccm maximum flow rate. The performance can be customized for practical applications such as micro gas chromatography. (paper)

Modeling Human Nonalcoholic Steatohepatitis-Associated Changes in Drug Transporter Expression Using Experimental Rodent Models

OpenAIRE

Canet, Mark J.; Hardwick, Rhiannon N.; Lake, April D.; Dzierlenga, Anika L.; Clarke, John D.; Cherrington, Nathan J.

2014-01-01

Nonalcoholic fatty liver disease is a prevalent form of chronic liver disease that can progress to the more advanced stage of nonalcoholic steatohepatitis (NASH). NASH has been shown to alter drug transporter regulation and may have implications in the development of adverse drug reactions. Several experimental rodent models have been proposed for the study of NASH, but no single model fully recapitulates all aspects of the human disease. The purpose of the current study was to determine whic...

Staging of fibrosis in experimental non-alcoholic steatohepatitis by quantitative molecular imaging in rat models

International Nuclear Information System (INIS)

Schnabl, Bernd; Farshchi-Heydari, Salman; Loomba, Rohit; Mattrey, Robert F.; Hoh, Carl K.; Sirlin, Claude B.; Brenner, David A.; Behling, Cynthia A.; Vera, David R.

2016-01-01

Objectives: The aim of this study was to test the ability of hepatocyte-specific functional imaging to stage fibrosis in experimental rat models of liver fibrosis and progressive NASH. Using ROC analysis we tested the ability of a functional imaging metric to discriminate early (F1) from moderate (F2) fibrosis in the absence and presence of non-alcoholic steatohepatitis, which has not been achieved by any modality other than biopsy. Methods: Galactosyl Human Serum Albumin (GSA) was radiolabeled with the positron-emitter, 68 Ga, and injected (i.v., 45–95 μCi, 1.5 pmol/g TBW) into 44 healthy, 19 DEN-, and 22 CDAA-treated male rats. Quantification of liver function was achieved by calculating T90, defined as the time for the liver to accumulate 90 percent of the [ 68 Ga]GSA plateau value. All livers were excised immediately after imaging and prepared for a “blinded” histologic examination, which included fibrosis and fat content scores. Two sets of fibrosis scores were recorded for all of animals. The dominant fibrosis stage was recorded as the “Dominant Pattern” score and the “Maximum Pattern” score was assigned if a smaller distinct region with a higher fibrosis score was observed. Results: Animals with Dominant Pattern F0–F1 liver fibrosis (D − = 39) demonstrated significantly (P < 0.0001) faster accumulation of [ 68 Ga]GSA (2.40 ± 0.52 min) than those with moderate to advanced Dominant Pattern fibrosis F2 and F4 (D + = 26) (3.48 ± 1.01 min). ROC analysis (F0–F1 vs F2–F4) produced an area under the binormal curve (AUC) of 0.867 ± 0.045. Twenty-seven of the 65 rats had small regions with higher fibrosis scores. Six of these Maximum Pattern scores reclassified the animals from D − to D + . ROC analysis of F0–F1 versus F2–F4 rats without liver fat produced AUCs of 0.881 ± 0.053 for the Dominant Pattern Score and 0.944 ± 0.035 for the Maximum Pattern Score. Conclusions: PET Functional Imaging of [ 68 Ga]GSA accurately discriminates

Retrospective analysis of 56 edentulous dental arches restored with 344 single-stage implants using an immediate loading fixed provisional protocol: statistical predictors of implant failure.

Science.gov (United States)

Kinsel, Richard P; Liss, Mindy

2007-01-01

The purpose of this retrospective study was to evaluate the effects of implant dimensions, surface treatment, location in the dental arch, numbers of supporting implant abutments, surgical technique, and generally recognized risk factors on the survival of a series of single-stage Straumann dental implants placed into edentulous arches using an immediate loading protocol. Each patient received between 4 and 18 implants in one or both dental arches. Periapical radiographs were obtained over a 2- to 10-year follow-up period to evaluate crestal bone loss following insertion of the definitive metal-ceramic fixed prostheses. Univariate tests for failure rates as a function of age ( or = 60 years), gender, smoking, bone grafting, dental arch, surface type, anterior versus posterior, number of implants per arch, and surgical technique were made using Fisher exact tests. The Cochran-Armitage test for trend was used to evaluate the presence of a linear trend in failure rates regarding implant length and implant diameter. Logistic regression modeling was used to determine which, if any, of the aforementioned factors would predict patient and implant failure. A significance criterion of P = .05 was utilized. Data were collected for 344 single-stage implants placed into 56 edentulous arches (39 maxillae and 17 mandibles) of 43 patients and immediately loaded with a 1-piece provisional fixed prosthesis. A total of 16 implants failed to successfully integrate, for a survival rate of 95.3%. Increased rates of failure were associated with reduced implant length, placement in the posterior region of the jaw, increased implant diameter, and surface treatment. Implant length emerged as the sole significant predictor of implant failure. In this retrospective analysis of 56 consecutively treated edentulous arches with multiple single-stage dental implants loaded immediately, reduced implant length was the sole significant predictor of failure.

Audiovisual integration in speech perception: a multi-stage process

DEFF Research Database (Denmark)

Eskelund, Kasper; Tuomainen, Jyrki; Andersen, Tobias

2011-01-01

investigate whether the integration of auditory and visual speech observed in these two audiovisual integration effects are specific traits of speech perception. We further ask whether audiovisual integration is undertaken in a single processing stage or multiple processing stages....

Limits on visibility of single heavy atoms in the scanning transmission electron microscope: an experimental study

Energy Technology Data Exchange (ETDEWEB)

Wall, J.S.

1979-01-01

Theoretical calculations of the visibility of single heavy atoms on thin carbon substrates have predicted higher signal to noise ratios then experimentally observed. Six experimental measurements were performed to determine where the theory is inadequate, five to determine the absolute value of heavy atom scattering cross sections in practical units, and one to determine substrate noise in some practical units. The practical unit of measure was chosen to be the scattering power of one carbon atom as determined by an internal standard, Tobacco Mosaic Virus. Measurements were performed on the following targets on thin carbon substrates: single isolated uranium atoms; silicotungstate clusters; colloidal platinum particles; fd bacteriophage embedded in negative strain; and fd bacteriophage reacted with a known quantity of heavy atom reagent. These measurements suggest that the scattering power of one heavy atom is approximately 9 +- 4 carbon atom equivalents, instead of 15 to 24 predicted by theory. The same techniques were used to measure intensity fluctuations from area to area of a clean substrate. Substrate noise was found to be less than expected for squares of width less than 10A, but up to 2.5 times greater than expected for larger squares. These signal and noise measurements have been combined to give an empirical formula for calculating signal to noise ratios from specimen and microscope parameters.

Single photon emission computed tomography with N-isopropyl-p-(/sup 123/I) iodoamphetamine in dementia of the Alzheimer type. Comparative study in each stage and the difference between the hemispheres

Energy Technology Data Exchange (ETDEWEB)

Tsunoda, Masahiko; Fujii, Tsutomu; Tanii, Yasuyuki; Yasui, Shinichi; Yuasa, Satoru; Shimizu, Akinori; Kurachi, Masayoshi; Seki, Hiroyasu; Fukuta, Tsutomu

1989-05-01

Correlation between brain uptake of N-isopropyl-p-(I-123)iodoamphetamine (I-123 IMP), as shown on single photon emission computed tomography (SPECT) scans, and clinical stages was examined in 8 patients with Alzheimer type dementia. The patients were clinically staged as Stage I (3), Stage II (3), or Stage III (2). The count ratio of each cerebral lobe to the cerebellum was calculated on horizontal SPECT scans. Stage I patients had a decreased I-123 IMP uptake in the temporal and parietal lobes. The decreased uptake in these areas became marked in Stage II patients, with diffusely slight uptake of I-123 IMP in the brain. In Stage III patients, the uptake of I-123 IMP was markedly decreased in the whole brain, including temporal, parietal, and frontal lobes. For five patients of Stage II and III, bilateral differences in the cerebral hemispheres were observed, corresponding to neurologic symptoms. Iodine-123 IMP SPECT was thus considered useful in clinically evaluating Alzheimer type dementia and in determining degenerative process of this disease. (Namekawa, K).

Design and experimental validation of Unilateral Linear Halbach magnet arrays for single-sided magnetic resonance.

Science.gov (United States)

Bashyam, Ashvin; Li, Matthew; Cima, Michael J

2018-07-01

Single-sided NMR has the potential for broad utility and has found applications in healthcare, materials analysis, food quality assurance, and the oil and gas industry. These sensors require a remote, strong, uniform magnetic field to perform high sensitivity measurements. We demonstrate a new permanent magnet geometry, the Unilateral Linear Halbach, that combines design principles from "sweet-spot" and linear Halbach magnets to achieve this goal through more efficient use of magnetic flux. We perform sensitivity analysis using numerical simulations to produce a framework for Unilateral Linear Halbach design and assess tradeoffs between design parameters. Additionally, the use of hundreds of small, discrete magnets within the assembly allows for a tunable design, improved robustness to variability in magnetization strength, and increased safety during construction. Experimental validation using a prototype magnet shows close agreement with the simulated magnetic field. The Unilateral Linear Halbach magnet increases the sensitivity, portability, and versatility of single-sided NMR. Copyright © 2018 Elsevier Inc. All rights reserved.

Intercommunications of indexes of speed and power qualities of sportsmen single combat on the stage of the specialized base preparation

Directory of Open Access Journals (Sweden)

A.O. Nykytenko

2013-01-01

Full Text Available The purpose of work is a study of interdependence between indexes specially-preparatory and general preparatory exercises of sportsmen (boxing, sporting hand-to-hand fight hopak, fencing. 42 sportsmen took part in researches. Statistical reliable intercommunications are set: a indexes of force of shots by hands with the indexes of rate of single movement; b indexes of force of shots by feet with indexes from maximal force of muscles (tractive forces; c indexes of speed of shots by hands (pricking with the indexes of distance of shove of balls by mass 300 gramme; d indexes of speed of movement a step in a battle bar with indexes: speeds of shots by hands (pricking; e indexes of frequency of shots of boxers and sportsmen hand-to-hand fight hopak with the indexes of frequency of movement (manoeuvring on feet. Facilities which it is expedient to apply in the training process of single combats on this stage of long-term preparation are certain.

Upgrading of the symbiosis of Nitrosomanas and anammox bacteria in a novel single-stage partial nitritation-anammox system: Nitrogen removal potential and Microbial characterization.

Science.gov (United States)

Liu, Yuan; Niu, Qigui; Wang, Shaopo; Ji, Jiayuan; Zhang, Yu; Yang, Min; Hojo, Toshimasa; Li, Yu-You

2017-11-01

A novel single-stage partial nitritation-anammox process equipped with porous functional suspended carriers was developed at 25°C in a CSTR by controlling dissolved oxygen <0.3mg/L. The nitrogen removal performance was almost unchanged over a nitrogen loading rate ranging from 0.5 to 2.5kgNH 4 + -N/m 3 /d with a high nitrogen removal efficiency of 81.1%. The specific activity of AOB and anammox bacteria was of 3.00g-N/g-MLVSS/d (the suspended sludge), 3.56g-N/g-MLVSS/d (the biofilm sludge), respectively. The results of pyrosequencing revealed that Nitrosomonas (5.66%) and Candidatus_Kuenenia (4.95%) were symbiotic in carriers while Nitrosomonas (40.70%) was predominant in the suspended flocs. Besides, two specific types of heterotrophic filamentous bacteria in the suspended flocs (Haliscomenobacter) and the functional carrier biofilm (Longilinea) were shown to confer structural integrity to the aggregates. The novel single-stage partial nitritation-anammox process equipped with functional suspended carriers was shown to have good potential for the nitrogen-rich wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental Investigation of a Forward Swept Rotor in a Multistage Fan with Inlet Distortion

Directory of Open Access Journals (Sweden)

Aspi R. Wadia

2011-01-01

Full Text Available Previous studies of transonic swept rotors in single stage fans have demonstrated the potential of significant improvements in both efficiency and stall margin with forward swept blading. This paper extends the assessment of the payoff derived from forward sweep to multistage configurations. The experimental investigation compare two builds of an advanced two-stage fan configuration tested alternately with a radial and a forward swept stage 1 blade. In the two-stage evaluations, the testing was extended to include the effect on inlet flow distortion. While the common second stage among the two builds prevented the overall fan from showing clean inlet performance and stability benefits with the forward swept rotor 1, this configuration did demonstrate superior front stage efficiency and tolerance to inlet distortion. Having obtained already low distortion sensitivity with the radial rotor 1 configuration relative to current production military fan standards, the sensitivity to inlet distortion was halved with the forward swept rotor 1 configuration. In the case of the 180-degree one-per-rev distortion pattern, the two-stage configuration was evaluated both with and without inlet guide vanes (IGVs. The presence of the inlet guide vanes had a profound impact in lowering the two-stage fan's sensitivity with inlet distortion.

Design model for bending vibrations of single-stage tunnel fan rotor

Science.gov (United States)

Krasyuk, AM; Kosykh, PV

2018-03-01

Using of one-mass model of tunnel fan rotor is justified for estimation calculation of the natural bending vibrations frequency during the design stage. It’s shown that the evaluative computation of the main axial tunnel fan at the early design stage yields the acceptable accuracy. It is shown that after completion of the design, the mass of the stepped-type shaft differs from the mass of the calculated uniform-diameter shaft no more than by 40%. Inclusion of this additional mass in the estimation calculation makes it possible to improve the calculation accuracy. The region of the dimensionless rotor design parameters at which the relative difference of frequency in the evaluative and verification calculations is not higher than 5 % is determined.

Comparison of two-stage thermophilic (68 degrees C/55 degrees C) anaerobic digestion with one-stage thermophilic (55 degrees C) digestion of cattle manure

DEFF Research Database (Denmark)

Nielsen, H.B.; Mladenovska, Zuzana; Westermann, Peter

2004-01-01

A two-stage 68degreesC/55degreesC anaerobic degradation process for treatment of cattle manure was studied. In batch experiments, an increase of the specific methane yield, ranging from 24% to 56%, was obtained when cattle manure and its fractions (fibers and liquid) were pretreated at 68degrees......, was compared with a conventional single-stage reactor running at 55degreesC with 15-days HRT. When an organic loading of 3 g volatile solids (VS) per liter per day was applied, the two-stage setup had a 6% to 8% higher specific methane yield and a 9% more effective VS-removal than the conventional single......-stage reactor. The 68degreesC reactor generated 7% to 9% of the total amount of methane of the two-stage system and maintained a volatile fatty acids (VFA) concentration of 4.0 to 4.4 g acetate per liter. Population size and activity of aceticlastic methanogens, syntrophic bacteria, and hydrolytic...

Optimized multiple linear mappings for single image super-resolution

Science.gov (United States)

Zhang, Kaibing; Li, Jie; Xiong, Zenggang; Liu, Xiuping; Gao, Xinbo

2017-12-01

Learning piecewise linear regression has been recognized as an effective way for example learning-based single image super-resolution (SR) in literature. In this paper, we employ an expectation-maximization (EM) algorithm to further improve the SR performance of our previous multiple linear mappings (MLM) based SR method. In the training stage, the proposed method starts with a set of linear regressors obtained by the MLM-based method, and then jointly optimizes the clustering results and the low- and high-resolution subdictionary pairs for regression functions by using the metric of the reconstruction errors. In the test stage, we select the optimal regressor for SR reconstruction by accumulating the reconstruction errors of m-nearest neighbors in the training set. Thorough experimental results carried on six publicly available datasets demonstrate that the proposed SR method can yield high-quality images with finer details and sharper edges in terms of both quantitative and perceptual image quality assessments.

Meta-analysis of Gaussian individual patient data: Two-stage or not two-stage?

Science.gov (United States)

Morris, Tim P; Fisher, David J; Kenward, Michael G; Carpenter, James R

2018-04-30

Quantitative evidence synthesis through meta-analysis is central to evidence-based medicine. For well-documented reasons, the meta-analysis of individual patient data is held in higher regard than aggregate data. With access to individual patient data, the analysis is not restricted to a "two-stage" approach (combining estimates and standard errors) but can estimate parameters of interest by fitting a single model to all of the data, a so-called "one-stage" analysis. There has been debate about the merits of one- and two-stage analysis. Arguments for one-stage analysis have typically noted that a wider range of models can be fitted and overall estimates may be more precise. The two-stage side has emphasised that the models that can be fitted in two stages are sufficient to answer the relevant questions, with less scope for mistakes because there are fewer modelling choices to be made in the two-stage approach. For Gaussian data, we consider the statistical arguments for flexibility and precision in small-sample settings. Regarding flexibility, several of the models that can be fitted only in one stage may not be of serious interest to most meta-analysis practitioners. Regarding precision, we consider fixed- and random-effects meta-analysis and see that, for a model making certain assumptions, the number of stages used to fit this model is irrelevant; the precision will be approximately equal. Meta-analysts should choose modelling assumptions carefully. Sometimes relevant models can only be fitted in one stage. Otherwise, meta-analysts are free to use whichever procedure is most convenient to fit the identified model. © 2018 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Specific features of the flow structure in a reactive type turbine stage

Science.gov (United States)

Chernikov, V. A.; Semakina, E. Yu.

2017-04-01

The results of experimental studies of the gas dynamics for a reactive type turbine stage are presented. The objective of the studies is the measurement of the 3D flow fields in reference cross sections, experimental determination of the stage characteristics, and analysis of the flow structure for detecting the sources of kinetic energy losses. The integral characteristics of the studied stage are obtained by averaging the results of traversing the 3D flow over the area of the reference cross sections before and behind the stage. The averaging is performed using the conservation equations for mass, total energy flux, angular momentum with respect to the axis z of the turbine, entropy flow, and the radial projection of the momentum flux equation. The flow parameter distributions along the channel height behind the stage are obtained in the same way. More thorough analysis of the flow structure is performed after interpolation of the experimentally measured point parameter values and 3D flow velocities behind the stage. The obtained continuous velocity distributions in the absolute and relative coordinate systems are presented in the form of vector fields. The coordinates of the centers and the vectors of secondary vortices are determined using the results of point measurements of velocity vectors in the cross section behind the turbine stage and their subsequent interpolation. The approach to analysis of experimental data on aerodynamics of the turbine stage applied in this study allows one to find the detailed space structure of the working medium flow, including secondary coherent vortices at the root and peripheral regions of the air-gas part of the stage. The measured 3D flow parameter fields and their interpolation, on the one hand, point to possible sources of increased power losses, and, on the other hand, may serve as the basis for detailed testing of CFD models of the flow using both integral and local characteristics. The comparison of the numerical and

Physiological Changes in Ewes Conceived Single or Twins Fetuses Related with Survivability of Lambs

International Nuclear Information System (INIS)

El-Tarabany, A.A.

2012-01-01

The number of 239 (137 in year 2009 and 102 in 2010) pregnant ewes with the same age and average live body weight were used in the present study. The experimental does reared under same conditions during May to September in 2009 and August to December in 2010, respectively. The available data for each animal were obtained from the recodes. The classified of breeds and total numbers used in this study were (Ossimi =49, Barki =47, Rahmani =60 and crossbred =83). Season of lambing started in October to November in 2009 and January and February in 2010. After parturition, the does were classified according to litter size into two groups. The ewes in the 1st and 2nd groups were labor single or twins lamb, respectively. The results showed that progressed pregnancy stages related with decreases in concentrations of immunity function (total proteins, albumin and globulin), cholesterol, glucose and calcium in serum of pregnant ewes. On the other hand, enzymes activities of liver functions (GOT, GPT and γGT), creatinine, triglycerides and phosphorus increased in serum of pregnant ewes with progressed pregnancy stages. Progesterone and parathormone concentrations showed opposite trends to those obtained levels with progressed pregnancy stages. Comparison between ewes conceived single or twins fetuses showed that most blood components values are related with survivability of lambs. In ewes conceived single fetus recorded higher values of total proteins, albumin, globulin, glucose and calcium than ewes conceived twins fetuses. On the other hand, GOT, GPT and γGT, cholesterol, triglycerides, creatinine, urea and phosphorus concentrations were lower in ewes conceived single fetus than in ewes conceived twins fetuses. On the opposite, progesterone and parathormone concentrations were lower in single than in twins fetuses

Outcompeting nitrite-oxidizing bacteria in single-stage nitrogen removal in sewage treatment plants: a model-based study.

Science.gov (United States)

Pérez, Julio; Lotti, Tommaso; Kleerebezem, Robbert; Picioreanu, Cristian; van Loosdrecht, Mark C M

2014-12-01

This model-based study investigated the mechanisms and operational window for efficient repression of nitrite oxidizing bacteria (NOB) in an autotrophic nitrogen removal process. The operation of a continuous single-stage granular sludge process was simulated for nitrogen removal from pretreated sewage at 10 °C. The effects of the residual ammonium concentration were explicitly analyzed with the model. Competition for oxygen between ammonia-oxidizing bacteria (AOB) and NOB was found to be essential for NOB repression even when the suppression of nitrite oxidation is assisted by nitrite reduction by anammox (AMX). The nitrite half-saturation coefficient of NOB and AMX proved non-sensitive for the model output. The maximum specific growth rate of AMX bacteria proved a sensitive process parameter, because higher rates would provide a competitive advantage for AMX. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nano positioning control for dual stage using minimum order observer

International Nuclear Information System (INIS)

Kim, Hong Gun

2012-01-01

A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision positioning system (100 mm stroke and ±10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory, a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE

Nano positioning control for dual stage using minimum order observer

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Gun [Jeonju University, Jeonju (Korea, Republic of)

2012-03-15

A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision positioning system (100 mm stroke and {+-}10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory, a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE.

The tensile effect on crack formation in single crystal silicon irradiated by intense pulsed ion beam

Science.gov (United States)

Liang, Guoying; Shen, Jie; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Yan, Sha; Zhang, Xiaofu; Yu, Xiao; Le, Xiaoyun

2017-10-01

Improving antifatigue performance of silicon substrate is very important for the development of semiconductor industry. The cracking behavior of silicon under intense pulsed ion beam irradiation was studied by numerical simulation in order to understand the mechanism of induced surface peeling observed by experimental means. Using molecular dynamics simulation based on Stillinger Weber potential, tensile effect on crack growth and propagation in single crystal silicon was investigated. Simulation results reveal that stress-strain curves of single crystal silicon at a constant strain rate can be divided into three stages, which are not similar to metal stress-strain curves; different tensile load velocities induce difference of single silicon crack formation speed; the layered stress results in crack formation in single crystal silicon. It is concluded that the crack growth and propagation is more sensitive to strain rate, tensile load velocity, stress distribution in single crystal silicon.

Probing the early stages of salt nucleation—Experimental and theoretical investigations of sodium/potassium thiocyanate cluster anions

Science.gov (United States)

Deng, S. H. M.; Kong, Xiang-Yu; Wang, Xue-Bin

2015-01-01

Due to the fast solvent evaporation in electrospray ionization (ESI), the concentration of initially dilute electrolyte solutions rapidly increases to afford the formation of supersaturated droplets and generation of various pristine anhydrous salt clusters in the gas phase. The size, composition, and charge distributions of these clusters, in principle, witness the nucleation evolution in solutions. Herein, we report a microscopic study on the initial stage of nucleation and crystallization of sodium/potassium thiocyanate salt solutions simulated in the ESI process. Singly charged M x (SCN)x + 1 - , doubly charged M y (SCN)y + 2 2 - (M = Na, K), and triply charged K z (SCN)z + 3 3 - anion clusters (x, y, and z stand for the number of alkali atoms in the singly, doubly, and triply charged clusters, respectively) were produced via electrospray of the corresponding salt solutions and were characterized by negative ion photoelectron spectroscopy (NIPES). The vertical detachment energies (VDEs) of these sodium/potassium thiocyanate cluster anions were obtained, and theoretical calculations were carried out for the sodium thiocyanate clusters in assisting spectral identification. The measured VDEs of singly charged anions M x (SCN)x + 1 - (M = Na and K) demonstrate that they are superhalogen anions. The existence of doubly charged anions M y (SCN)y + 2 2 - (y = 2x, x ≥ 4 and 3 for M = Na and K, respectively) and triply charged anions K z (SCN)z + 3 3 - (z = 3x, x ≥ 6) was initially discovered from the photoelectron spectra for those singly charged anions of M x (SCN)x + 1 - with the same mass-to-charge ratio (m/z), and later independently confirmed by the observation of their distinct mass spectral distributions and by taking their NIPE spectra for those pure multiply charged anions with their m/z different from the singly charged species. For large clusters, multiply charged clusters were found to become preferred, but at higher temperatures, those multiply charged

The MARVEL domain protein, Singles Bar, is required for progression past the pre-fusion complex stage of myoblast fusion.

Science.gov (United States)

Estrada, Beatriz; Maeland, Anne D; Gisselbrecht, Stephen S; Bloor, James W; Brown, Nicholas H; Michelson, Alan M

2007-07-15

Multinucleated myotubes develop by the sequential fusion of individual myoblasts. Using a convergence of genomic and classical genetic approaches, we have discovered a novel gene, singles bar (sing), that is essential for myoblast fusion. sing encodes a small multipass transmembrane protein containing a MARVEL domain, which is found in vertebrate proteins involved in processes such as tight junction formation and vesicle trafficking where--as in myoblast fusion--membrane apposition occurs. sing is expressed in both founder cells and fusion competent myoblasts preceding and during myoblast fusion. Examination of embryos injected with double-stranded sing RNA or embryos homozygous for ethane methyl sulfonate-induced sing alleles revealed an identical phenotype: replacement of multinucleated myofibers by groups of single, myosin-expressing myoblasts at a stage when formation of the mature muscle pattern is complete in wild-type embryos. Unfused sing mutant myoblasts form clusters, suggesting that early recognition and adhesion of these cells are unimpaired. To further investigate this phenotype, we undertook electron microscopic ultrastructural studies of fusing myoblasts in both sing and wild-type embryos. These experiments revealed that more sing mutant myoblasts than wild-type contain pre-fusion complexes, which are characterized by electron-dense vesicles paired on either side of the fusing plasma membranes. In contrast, embryos mutant for another muscle fusion gene, blown fuse (blow), have a normal number of such complexes. Together, these results lead to the hypothesis that sing acts at a step distinct from that of blow, and that sing is required on both founder cell and fusion-competent myoblast membranes to allow progression past the pre-fusion complex stage of myoblast fusion, possibly by mediating fusion of the electron-dense vesicles to the plasma membrane.

Efficacy of single-stage breast-conserving treatment using multicatheter partial breast brachytherapy evaluated by GEC-ESTRO phase 3 trial.

Science.gov (United States)

Sato, Kazuhiko; Fuchikami, Hiromi; Kato, Masahiro; Shimo, Takahiro; Kubota, Jun; Takeda, Naoko; Inoue, Yuko; Seto, Hiroshi; Okawa, Tomohiko

2017-10-01

The GEC-ESTRO has reported the equivalent outcomes of partial breast irradiation (PBI) using multicatheter interstitial brachytherapy (MCB) to whole breast irradiation (WBI) in breast-conserving therapy (BCT). We performed single-stage BCT with partial breast brachytherapy by intraoperative catheter placement. After the categorization of patients into inclusion and exclusion criteria on this trial, our databases were evaluated in order to translate it to Japanese patients. Patients undergoing BCT were retrospectively examined between November 2007 and December 2015. The technique is an open-cavity implant with a dose of 32 Gy in 8 fractions. The 4-year clinical outcomes of MCB-PBI were evaluated in the 2 distinct categories, and the comparison of the outcomes of MCB-PBI with WBI was performed in patients with unfavorable features. Of a total of 501 lesions undergoing BCT, 301 lesions were treated with MCB-PBI and 200 lesions with WBI. At the median follow-up time of 52 months, the 4-year rate of ipsilateral breast tumor recurrence (IBTR)-free, disease-free (DFS), and overall survival (OS) in patients with MCB-PBI and WBI were 98.9% vs. 98.0% ( p = 0.56), 97.0% vs. 95.3% ( p = 0.78), and 99.6% vs. 98.2% ( p = 0.38), respectively. Although in exclusion cohort treated with MCB-PBI, IBTR-free, and disease-free survival were significantly worse than in inclusion cohort, non-significantly worse outcomes was demonstrated than in exclusion cohort with WBI; IBTR-free survival (95.0% vs. 97.2%, p = 0.24), and disease-free survival (95.0% vs. 95.8%, p = 0.31). Single-stage BCT using MCB-PBI offered similar tumor control rates compering to WBI. However, further research is needed to define the benefit for patients with an exclusion criteria.

A Novel Dual-Stage Hydrothermal Flow Reactor

DEFF Research Database (Denmark)

Hellstern, Henrik Christian; Becker, Jacob; Hald, Peter

2015-01-01

The dual-stage reactor is a novel continuous flow reactor with two reactors connected in series. It is designed for hydrothermal flow synthesis of nanocomposites, in which a single particle consists of multiple materials. The secondary material may protect the core nanoparticle from oxidation....... The dual-stage reactor combines the ability to produce advanced materials with an upscaled capacity in excess of 10 g/hour (dry mass). TiO2 was synthesized in the primary reactor and reproduced previous results. The dual-stage capability was succesfully demonstrated with a series of nanocomposites incl. Ti...

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.

Experimental characterization of the thermal and solar behavior of constructed houses; Caracterizacion experimental del comportamiento termico y solar de viviendas construidas

Energy Technology Data Exchange (ETDEWEB)

Carrillo, A.; Jurado, L.; Molina, J. C.; Druet, L.

2008-07-01

Nowadays, detailed simulation models are widely used to assess thermal performance of buildings, specially during the design stage. However it is usual to report significant differences in predicted thermal performance when confronted with measured data. Therefore the model should be calibrated. In this paper, the PSTAR framework (Subbarao, 1988) is used to calibrate a Energy Plus model of a single-family dwelling. PSTAR method yields a set of renormalization coefficients that offer quantitative interpretation of the predicted vs measured differences. Other experimental tests are used to gain additional insight on how the model should be twicked judiciously. Once calibrated, the model matches three important thermal parameters of the real buildings: heat loss coefficient, thermal mass and solar gains. (Author)

Effect of sorbitol, single, and multidose activated charcoal administration on carprofen absorption following experimental overdose in dogs.

Science.gov (United States)

Koenigshof, Amy M; Beal, Matthew W; Poppenga, Robert H; Jutkowitz, L Ari

2015-01-01

To compare the effectiveness of single dose activated charcoal, single dose activated charcoal with sorbitol, and multidose activated charcoal in reducing plasma carprofen concentrations following experimental overdose in dogs. Randomized, four period cross-over study. University research setting. Eight healthy Beagles. A 120 mg/kg of carprofen was administered orally to each dog followed by either (i) a single 2 g/kg activated charcoal administration 1 hour following carprofen ingestion (AC); (ii) 2 g/kg activated charcoal with 3.84 g/kg sorbitol 1 hour following carprofen ingestion (ACS); (iii) 2 g/kg activated charcoal 1 hour after carprofen ingestion and repeated every 6 hours for a total of 4 doses (MD); (iv) no treatment (control). Plasma carprofen concentrations were obtained over a 36-hour period following carprofen ingestion for each protocol. Pharmacokinetic modeling was performed and time versus concentration, area under the curve, maximum plasma concentration, time to maximum concentration, and elimination half-life were calculated and compared among the groups using ANOVA followed by Tukey's multiple comparisons test. Activated charcoal, activated charcoal with sorbitol (ACS), and multiple-dose activated charcoal (MD) significantly reduced the area under the curve compared to the control group. AC and MD significantly reduced the maximum concentration when compared to the control group. MD significantly reduced elimination half-life when compared to ACS and the control group. There were no other significant differences among the treatment groups. Activated charcoal and ACS are as effective as MD in reducing serum carprofen concentrations following experimental overdose in dogs. Prospective studies are warranted to evaluate the effectiveness of AC, ACS, and MD in the clinical setting. © Veterinary Emergency and Critical Care Society 2015.

Late Financial Distress Process Stages and Financial Ratios

DEFF Research Database (Denmark)

Sormunen, Nina; Laitinen, Teija

2012-01-01

stage affects the classification ability of single financial ratios and financial distress prediction models in short-term financial distress prediction. The study shows that the auditor's GC task could be supported by paying attention to the financial distress process stage. The implications...... of these findings for auditors and every stakeholder of business firms are considered....

Do bacterial cell numbers follow a theoretical Poisson distribution? Comparison of experimentally obtained numbers of single cells with random number generation via computer simulation.

Science.gov (United States)

Koyama, Kento; Hokunan, Hidekazu; Hasegawa, Mayumi; Kawamura, Shuso; Koseki, Shigenobu

2016-12-01

We investigated a bacterial sample preparation procedure for single-cell studies. In the present study, we examined whether single bacterial cells obtained via 10-fold dilution followed a theoretical Poisson distribution. Four serotypes of Salmonella enterica, three serotypes of enterohaemorrhagic Escherichia coli and one serotype of Listeria monocytogenes were used as sample bacteria. An inoculum of each serotype was prepared via a 10-fold dilution series to obtain bacterial cell counts with mean values of one or two. To determine whether the experimentally obtained bacterial cell counts follow a theoretical Poisson distribution, a likelihood ratio test between the experimentally obtained cell counts and Poisson distribution which parameter estimated by maximum likelihood estimation (MLE) was conducted. The bacterial cell counts of each serotype sufficiently followed a Poisson distribution. Furthermore, to examine the validity of the parameters of Poisson distribution from experimentally obtained bacterial cell counts, we compared these with the parameters of a Poisson distribution that were estimated using random number generation via computer simulation. The Poisson distribution parameters experimentally obtained from bacterial cell counts were within the range of the parameters estimated using a computer simulation. These results demonstrate that the bacterial cell counts of each serotype obtained via 10-fold dilution followed a Poisson distribution. The fact that the frequency of bacterial cell counts follows a Poisson distribution at low number would be applied to some single-cell studies with a few bacterial cells. In particular, the procedure presented in this study enables us to develop an inactivation model at the single-cell level that can estimate the variability of survival bacterial numbers during the bacterial death process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Single-Staged Improved Tubularized Preputial/Penile Skin Flap Urethroplasty for Obliterated Anterior Urethral Stricture: Long-Term Results.

Science.gov (United States)

Xue, Jing-Dong; Xie, Hong; Fu, Qiang; Feng, Chao; Guo, Hui; Xu, Yue-Min

2016-01-01

To present an improved tubularized flap (ITF) technique and report the outcome of single-stage urethroplasty using preputial/penile skin flaps (PSFs) for the treatment of obliterative anterior urethral strictures (AUSs). From January 2000 to June 2012, 42 cases of obliterative AUS (3-14 cm, mean 6.38 cm) with urethral plate unsalvageable were treated using PSF-ITF urethroplasty including longitudinal skin flap, circular island flap, L-flap, Q-flap. Patients were divided into 3 groups: pendulous urethral stricture (Group A), bulbar urethral stricture (Group B) and panurethral strictures (Group C). Patients were followed up by uroflowmetry, urethrography and ureteroscope when necessary. The mean follow-up in these patients was 65 months (range 36 months-15 years). The primary success rates at 3-year follow-up were 75, 75 and 60% for Groups A, B and C, respectively. The overall success rates were 85, 83 and 70% with the remedial measure of a single visual internal urethrotomy at 3-year follow-up. A total 60% of the patients in the study completed more than 5 years of follow-up with no additional recurrence. Improved tubularized preputial/PSF urethroplasty with relatively high overall satisfaction is a novel technique for treatment of AUS when there is inadequate urethral plate or obliterative defects. © 2016 S. Karger AG, Basel.

Experimental investigation of gasoline fumigation in a single cylinder direct injection (DI) diesel engine

International Nuclear Information System (INIS)

Sahin, Z.; Durgun, O.; Bayram, C.

2008-01-01

In the presented study, the effects of gasoline fumigation have been investigated experimentally in a single cylinder direct injection (DI) diesel engine. Gasoline has been introduced into the inlet air flow using an elementary carburetor and no other modification on the engine has been done. The effects of 2%, 4%, 6%, 8% and 10% (by vol.) gasoline fumigation have been investigated experimentally at the speeds of (900-1600) (rpm) and at the selected compression ratios of (18-23). From the experimental results it is determined that by application of gasoline fumigation effective power output increases at the levels of 4-9%, effective efficiency increases by approximately 1.5-4% and specific fuel consumption decreases by approximately 1.5-4%. It is also determined that 4-6% fumigation ratio range is the most favorable percentage interval of gasoline at the selected compression ratios for this engine. Because cost of gasoline is higher than diesel fuel in Turkey as well as in many of the other countries and the decrease ratio of specific fuel consumption is low, gasoline fumigation is not economic for this engine. In the presented study, heat balance tests have also been performed for 18 and 21 compression ratios. The heat balance has been investigated experimentally in respect of effective power, heat rejected to the cooling water, heat lost through exhaust, and other losses (unaccounted-for losses). Heat lost through exhaust decreases until 4-6% gasoline fumigation ratios and after these fumigation ratios it starts to increase because of increasing exhaust gas temperature. Heat rejected to the cooling water decreases at low fumigation ratios, but at high fumigation ratios it increases. Other losses generally exhibit an increasing tendency at low fumigation ratios

Clinical utility of simultaneous whole-body 18F-FDG PET/MRI as a single-step imaging modality in the staging of primary nasopharyngeal carcinoma.

Science.gov (United States)

Chan, Sheng-Chieh; Yeh, Chih-Hua; Yen, Tzu-Chen; Ng, Shu-Hang; Chang, Joseph Tung-Chieh; Lin, Chien-Yu; Yen-Ming, Tsang; Fan, Kang-Hsing; Huang, Bing-Shen; Hsu, Cheng-Lung; Chang, Kai-Ping; Wang, Hung-Ming; Liao, Chun-Ta

2018-03-03

Both head and neck magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) play a crucial role in the staging of primary nasopharyngeal carcinoma (NPC). In this study, we sought to prospectively investigate the clinical utility of simultaneous whole-body 18F-FDG PET/MRI for primary staging of NPC patients. We examined 113 patients with histologically confirmed NPC who underwent pretreatment, simultaneous whole-body PET/MRI and PET/CT for primary tumor staging. The images obtained with the different imaging modalities were interpreted independently and compared with each other. PET/MRI increased the accuracy of head and neck MRI for assessment of primary tumor extent in four patients via addition of FDG uptake information to increase the conspicuity of morphologically subtle lesions. PET/MR images were more discernible than PET/CT images for mapping tumor extension, especially intracranial invasion. Regarding the N staging assessment, the sensitivity of PET/MRI (99.5%) was higher than that of head and neck MRI (94.2%) and PET/CT (90.9%). PET/MRI was particularly useful for distinguishing retropharyngeal nodal metastasis from adjacent nasopharyngeal tumors. For distant metastasis evaluation, PET/MRI exhibited a similar sensitivity (90% vs. 86.7% vs. 83.3%), but higher positive predictive value (93.1% vs. 78.8% vs. 83.3%) than whole-body MRI and PET/CT, respectively. For tumor staging of NPC, simultaneous whole-body PET/MRI was more accurate than head and neck MRI and PET/CT, and may serve as a single-step staging modality.

Safety and efficacy of staged retrograde intrarenal surgery for large stone burden of renal stones in selected patients: A single-center experience

Directory of Open Access Journals (Sweden)

Cheng-Feng Lin

2017-06-01

Conclusion: To the best of our knowledge, RIRS for large renal stone manipulation is an effective and safe treatment modality currently. In our study, the single RIRS SFR was superior to PNL or SWL even when the stone burden was between 2.0 cm and 3.0 cm (80.2%. For those patients whose stone burden was over 3.0 cm or for those with comorbidities, staged RIRS resulted in a lower complication rate, reduced hospital stay, and better SFR (76.5%.

Staging gender and sexuality in experimental TV entertainment.

Science.gov (United States)

Mühleisen, Wencke

2008-01-01

Via examples from recent Norwegian experimental TV shows, this article explores the function of "eye-catchers," parodic (hetero)sexualization, female masquerade and neo-masculinization as strategies for "repetitions with a difference" of traditional styles and motifs by female show hosts, as well as the queer gendering and sexualization of men and masculinities by their male counterparts. Both formats represent innovative renegotiations of gender and sexuality that illustrate the relationship between post-modernism and queer aesthetics.

Chromium (Ⅵ) removal from aqueous solutions through powdered activated carbon countercurrent two-stage adsorption.

Science.gov (United States)

Wang, Wenqiang

2018-01-01

To exploit the adsorption capacity of commercial powdered activated carbon (PAC) and to improve the efficiency of Cr(VI) removal from aqueous solutions, the adsorption of Cr(VI) by commercial PAC and the countercurrent two-stage adsorption (CTA) process was investigated. Different adsorption kinetics models and isotherms were compared, and the pseudo-second-order model and the Langmuir and Freundlich models fit the experimental data well. The Cr(VI) removal efficiency was >80% and was improved by 37% through the CTA process compared with the conventional single-stage adsorption process when the initial Cr(VI) concentration was 50 mg/L with a PAC dose of 1.250 g/L and a pH of 3. A calculation method for calculating the effluent Cr(VI) concentration and the PAC dose was developed for the CTA process, and the validity of the method was confirmed by a deviation of <5%. Copyright © 2017. Published by Elsevier Ltd.

Experimental study of single-vertex $(e^{-}-e^{+})$ pair creation in a crystal

CERN Multimedia

2002-01-01

This experiment will study the newly predicted process of $e^{-}-e^{+}$ pair production by high energy photons incident along major axial direction of a single crystal. This process is based upon the well-known channeling properties of negatively charged particles along atomic rows of a crystal. The $e^{-}-e^{+}$ pair creation may proceed in a one-step process, without violating energy and momentum conversation laws, due to the lowering of the total energy of the channeled electron (Fig. 1). \\\\ \\\\ The pair creation rate should increase with increasing photon energies (above a threshold of a few GeV) and largely exceed the Bethe-Heitler process rate for photon energies of a few tens of GeV. It is also expected that the created particles share the photon energy nearly equally, in contrast with the rather flat energy distribution associated with the Bethe-Heitler process. \\\\ \\\\ The experimental set-up (Fig. 2) is designed for the study of those two features: photon energy dependence of the pair creation rate, an...

Label-Free, Single Molecule Resonant Cavity Detection: A Double-Blind Experimental Study

Directory of Open Access Journals (Sweden)

Maria V. Chistiakova

2015-03-01

Full Text Available Optical resonant cavity sensors are gaining increasing interest as a potential diagnostic method for a range of applications, including medical prognostics and environmental monitoring. However, the majority of detection demonstrations to date have involved identifying a “known” analyte, and the more rigorous double-blind experiment, in which the experimenter must identify unknown solutions, has yet to be performed. This scenario is more representative of a real-world situation. Therefore, before these devices can truly transition, it is necessary to demonstrate this level of robustness. By combining a recently developed surface chemistry with integrated silica optical sensors, we have performed a double-blind experiment to identify four unknown solutions. The four unknown solutions represented a subset or complete set of four known solutions; as such, there were 256 possible combinations. Based on the single molecule detection signal, we correctly identified all solutions. In addition, as part of this work, we developed noise reduction algorithms.

A two-stage constitutive model of X12CrMoWVNbN10-1-1 steel during elevated temperature

Science.gov (United States)

Zhu, Luobei; He, Jianli; Zhang, Ying

2018-02-01

In order to clarify the competition between work hardening (WH) caused by dislocation movements and the dynamic softening result from dynamic recovery (DRV) and dynamic recrystallization (DRX), a new two-stage flow stress model of X12CrMoWVNbN10-1-1 (X12) ferrite heat-resistant steel was established to describe the whole hot deformation behavior. And the parameters were determined by the experimental data operated on a Gleeble-3800 thermo- mechanical simulation. In this constitutive model, a single internal variable dislocation density evolution model is used to describe the influence of WH and DRV to flow stress. The DRX kinetic dynamic model can express accurately the contribution of DRX to the decline of flow stress, which was established on the Avrami equation. Furthermore, The established new model was compared with Fields-Bachofen (F-B) model and experimental data. The results indicate the new two-stage flow stress model can more accurately represent the hot deformation behavior of X12 ferrite heat-resistant steel, and the average error is only 0.0995.

The Naso-labial and lateral forehead flaps as a single stage: A case report and review of literature

Directory of Open Access Journals (Sweden)

Adigun I

2008-01-01

Full Text Available We present here the case of a patient with a major traumatic nasal loses who had a near-total nasal reconstruction as a single-stage procedure. A 35 year-old civil servant who was involved in a road traffic injury about two years before presentation. He sustained extensive and multiple facial injuries with complete loss of nasal cover and lining. Reconstruction was performed by using superiorly based, bilateral, nasolabial flaps to line the floor and the nasal septum, and a paramedian forehead flap for skin cover. The patient did well postoperatively and was discharged home on the 7 th postoperative day. If the principles concerning cover, support, and lining are adhered to, excellent functional and aesthetic results can be achieved as we have obtained in our patient.

Stages of neuronal network formation

International Nuclear Information System (INIS)

Woiterski, Lydia; Käs, Josef A; Claudepierre, Thomas; Luxenhofer, Robert; Jordan, Rainer

2013-01-01

Graph theoretical approaches have become a powerful tool for investigating the architecture and dynamics of complex networks. The topology of network graphs revealed small-world properties for very different real systems among these neuronal networks. In this study, we observed the early development of mouse retinal ganglion cell (RGC) networks in vitro using time-lapse video microscopy. By means of a time-resolved graph theoretical analysis of the connectivity, shortest path length and the edge length, we were able to discover the different stages during the network formation. Starting from single cells, at the first stage neurons connected to each other ending up in a network with maximum complexity. In the further course, we observed a simplification of the network which manifested in a change of relevant network parameters such as the minimization of the path length. Moreover, we found that RGC networks self-organized as small-world networks at both stages; however, the optimization occurred only in the second stage. (paper)

Multi-stage continuous alcohol fermentation with cane molasses

Energy Technology Data Exchange (ETDEWEB)

Chu, C J; Chiou, C J; Ng, A K; Lin, T C; Hwang, E C; Rao, C H

1970-01-01

It was reported that 6 to 7% ethanol was produced by single-stage continuous 12-hour cycle fermentation of molasses containing 12% sugar using a new strain, Saccharomyces formensensis, isolated from a stock culture. A higher yield of ethanol was obtained from 2-stage and 3-stage continuous fermentation of molasses containing more sugar at 24- and 36-hour cycles, respectively. In the 2-stage 24-hour cycle continuous fermentation of molasses containing 15% sugar with an agitation speed 300 rpm, 9.2% ethanol resulted. Only 3% sugar remained unconsumed. In the 3-stage 36-hour cycle continuous fermentation of molasses containing 15% sugar with 300 rpm agitation, 12.5% ethanol resulted.

Computational study of the first stage of hypersonic ion beam neutralization: The cross neutralization stage

International Nuclear Information System (INIS)

Pomot, C.; Dolique, J.M.

1975-01-01

A study is made of the first stage of evolution of a hypersonic ion beam in which thermoelectrons are emitted by a heated grid, known as the neutralizer. Downstream from the neutralizer there appears successively as a sheath a range of periodic and quasi-stationary electric field and a front where the electric field oscillates with the plasma frequency. The sheath is self-regulated. Some electrons are trapped in the periodic and stationary electric field. The characteristics of the periodic, quasi-stationary range correspond to those of both an experimental study and one-dimensional time-independent macroscopic theory. This quasi-stationary regime builds up in a time smaller than ω/subp/e -1 and is studied for a few periods ω/subP//sube/ -1 . The subsequent evolution of this state of nonequilibrium is not investigated. The experimental study has shown that, as for the neutralization of a subsonic ion beam, it leads to a field-free, homogeneous medium: a ''synthesized plasma.'' The importance of the first stage described herein, which may be called the gross neutralization stage, is due to the properties of mean neutrality in the current and in the charge insured by the regulating sheath, properties which will be preseved downstream

Experimental validation of tape springs to be used as thin-walled space structures

Science.gov (United States)

Oberst, S.; Tuttle, S. L.; Griffin, D.; Lambert, A.; Boyce, R. R.

2018-04-01

With the advent of standardised launch geometries and off-the-shelf payloads, space programs utilising nano-satellite platforms are growing worldwide. Thin-walled, flexible and self-deployable structures are commonly used for antennae, instrument booms or solar panels owing to their lightweight, ideal packaging characteristics and near zero energy consumption. However their behaviour in space, in particular in Low Earth Orbits with continually changing environmental conditions, raises many questions. Accurate numerical models, which are often not available due to the difficulty of experimental testing under 1g-conditions, are needed to answer these questions. In this study, we present on-earth experimental validations, as a starting point to study the response of a tape spring as a representative of thin-walled flexible structures under static and vibrational loading. Material parameters of tape springs in a singly (straight, open cylinder) and a doubly curved design, are compared to each other by combining finite element calculations, with experimental laser vibrometry within a single and multi-stage model updating approach. While the determination of the Young's modulus is unproblematic, the damping is found to be inversely proportional to deployment length. With updated material properties the buckling instability margin is calculated using different slenderness ratios. Results indicate a high sensitivity of thin-walled structures to miniscule perturbations, which makes proper experimental testing a key requirement for stability prediction on thin-elastic space structures. The doubly curved tape spring provides closer agreement with experimental results than a straight tape spring design.

Alliance-focused therapy for anorexia nervosa: integrative relational and behavioral change treatments in a single-case experimental design.

Science.gov (United States)

Satir, Dana A; Goodman, David M; Shingleton, Rebecca M; Porcerelli, John H; Gorman, Bernard S; Pratt, Elizabeth M; Barlow, David H; Thompson-Brenner, Heather

2011-12-01

Evidence supporting outpatient treatments for anorexia nervosa (AN) is severely lacking, due to low retention and poor outcome. One explanation for drop-out is weak treatment alliances. A single-case experimental analysis accompanied by in-depth qualitative description is presented for Ms. O, who received a novel treatment for AN called Alliance Focused Treatment (AFT) that attends to ruptures in the alliance, interpersonal difficulties and emotional avoidance. At intake Ms. O met diagnostic criteria for AN, Major Depressive Disorder, and Social Phobia. She was characterized as having symptoms of Obsessive Compulsive, Avoidant, and Depressive personality disorders. Treatment began with a Baseline followed by the experimental (AFT) and comparison treatments (Behavioral Change Treatment [BCT]) using a replicated experimental single-case phase change design. Graphs of slopes of kilocalorie and alliance change facilitated observation of treatment effects. Ms. O participated in 16 sessions of AFT and 8 sessions of BCT with specific benefits. Ratings of the treatment alliance were consistently high and she evidenced significant changes in weight, quality of life, and personality pathology. Associations between rupture/repair episodes and kilocalorie increases were observed. The utility of the treatment relationship in facilitating emotional expression was evident. At posttreatment, Ms. O endorsed cognitive AN symptoms, although these were not explicitly treated. This study provides preliminary support for the feasibility and effect of AFT and BCT, and highlights the importance of the alliance in treating adults with AN. Further research on emotion regulation in AN and its effect on the treatment relationship are needed.

First TRUE Stage - Transport of solutes in an interpreted single fracture. Proceedings from the 4th international seminar

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-08-01

The First Stage of the Tracer Retention Understanding Experiments (TRUE-1) was initiated in 1994 and the experimental activities were officially concluded in December 1998 with the termination of the final test with radioactive sorbing tracers. The programme also included a laboratory programme focused on both generic (Aespoe HRL) and site-specific (Feature A) geological material. Modelling, both scopings, predictions and evaluation of the final tests with sorbing tracers has been performed parallel to the experimental work. The work and conclusions of the SKB TRUE project team have been published in a SKB technical report. The TRUE-1 experiments have also been subject to blind prediction and evaluation by an international group of modelling teams within the auspices of the Aespoe Task Force on Groundwater on Modelling of Groundwater Flow and Solute Transport. A list of relevant reports and publications related to the First TRUE Stage are presented in Appendix A. The present seminar provides a venue to present and discuss the results of the TRUE-1 experiments in terms of identified transport and retention processes and concepts/approaches used to model. However, given the fact that may international programs, including that of SKB, are either underway or preparing for site characterisation programs, the seminar provides a possibility to discuss research priorities and the specific data needs for development of a geological repository. In his opening address, the director of the Aespoe Hard Rock Laboratory emphasised the need to carefully integrate available experience from other research sites, e.g. Grimsel (Switzerland), Stripa (Sweden) and El Berrocal (Spain). The two important questions to be asked are; What do we know? What is the way forward? For the subsequent discussions four different discussion themes were identified; 1. Identification of transport processes. 2. Model concepts. 3. Site-specific data needs for a geological repository. 4. Research priorities

Slip-band formation and dislocation kinetics in the stage I deformation of neutron-irradiated copper single crystals

International Nuclear Information System (INIS)

Kitajima, Sadakichi; Shinohara, Kazutoshi; Kutsuwada, Masanori

1995-01-01

The velocity of edge and screw dislocations moving in primary slip bands and the formation rate of primary slip bands were measured in stage I deformation of neutron-irradiated copper single crystals at different strain rates at room temperature using micro-cinematography and optical micrography. The average velocity of edge dislocations was larger at least by one order than that of screw ones, and that of screw dislocations did not depend so strongly on strain rate. The formation rate of primary slip bands was proportional to strain rate. From these results, it is concluded that (1) jogs produced on moving dislocations by cutting dislocation loops result in the difference in velocity between edge and screw dislocations and (2) the change in the density of mobile dislocations as well as velocity of dislocations is responsible for the change of plastic strain rate of a crystal. (author)

One-dimensional simulation of a stirling three-stage pulse-tube refrigerator

NARCIS (Netherlands)

Etaati, M.A.; Mattheij, R.M.M.; Tijsseling, A.S.; Waele, de A.T.A.M.

2009-01-01

A one-dimensional mathematical model is derived for a three-stage pulse-tube refrigerator (PTR) that is based on the conservation laws and the ideal gas law. The three-stage PTR is regarded as three separate single-stage PTRs that are coupled via proper junction conditions. At the junctions there

One-dimensional simulation of a Stirling three-stage pulse-tube refrigerator

NARCIS (Netherlands)

Etaati, M.A.; Mattheij, R.M.M.; Tijsseling, A.S.; Waele, de A.T.A.M.

2009-01-01

A one-dimensional mathematical model is derived for a three-stage pulse-tube refrigerator (PTR) that is based on the conservation laws and the ideal gas law. The three-stage PTR is regarded as three separate single-stage PTRs that are coupled via proper junction conditions. At the junctions there

Sorting of cells of the same size, shape, and cell cycle stage for a single cell level assay without staining

Directory of Open Access Journals (Sweden)

Yomo Tetsuya

2006-06-01

Full Text Available Abstract Background Single-cell level studies are being used increasingly to measure cell properties not directly observable in a cell population. High-performance data acquisition systems for such studies have, by necessity, developed in synchrony. However, improvements in sample purification techniques are also required to reveal new phenomena. Here we assessed a cell sorter as a sample-pretreatment tool for a single-cell level assay. A cell sorter is routinely used for selecting one type of cells from a heterogeneous mixture of cells using specific fluorescence labels. In this case, we wanted to select cells of exactly the same size, shape, and cell-cycle stage from a population, without using a specific fluorescence label. Results We used four light scatter parameters: the peak height and area of the forward scatter (FSheight and FSarea and side scatter (SSheight and SSarea. The rat pheochromocytoma PC12 cell line, a neuronal cell line, was used for all experiments. The living cells concentrated in the high FSarea and middle SSheight/SSarea fractions. Single cells without cell clumps were concentrated in the low SS and middle FS fractions, and in the higher FSheight/FSarea and SSheight/SSarea fractions. The cell populations from these viable, single-cell-rich fractions were divided into twelve subfractions based on their FSarea-SSarea profiles, for more detailed analysis. We found that SSarea was proportional to the cell volume and the FSarea correlated with cell roundness and elongation, as well as with the level of DNA in the cell. To test the method and to characterize the basic properties of the isolated single cells, sorted cells were cultured in separate wells. The cells in all subfractions survived, proliferated and differentiated normally, suggesting that there was no serious damage. The smallest, roundest, and smoothest cells had the highest viability. There was no correlation between proliferation and differentiation. NGF increases

Experimental gingivitis induces systemic inflammatory markers in young healthy individuals: a single-subject interventional study.

Science.gov (United States)

Eberhard, Jörg; Grote, Karsten; Luchtefeld, Maren; Heuer, Wieland; Schuett, Harald; Divchev, Dimitar; Scherer, Ralph; Schmitz-Streit, Ruth; Langfeldt, Daniela; Stumpp, Nico; Staufenbiel, Ingmar; Schieffer, Bernhard; Stiesch, Meike

2013-01-01

We here investigated whether experimental gingivitis enhances systemic markers of inflammation which are also known as surrogate markers of atherosclerotic plaque development. Gingivitis is a low-level oral infection induced by bacterial deposits with a high prevalence within Western populations. A potential link between the more severe oral disease periodontitis and cardiovascular disease has already been shown. 37 non-smoking young volunteers with no inflammatory disease or any cardiovascular risk factors participated in this single-subject interventional study with an intra-individual control. Intentionally experimental oral inflammation was induced by the interruption of oral hygiene for 21 days, followed by a 21-days resolving phase after reinitiation of oral hygiene. Primary outcome measures at baseline, day 21 and 42 were concentrations of hsCRP, IL-6, and MCP-1, as well as adhesion capacity and oxLDL uptake of isolated blood monocytes. The partial cessation of oral hygiene procedures was followed by the significant increase of gingival bleeding (34.0%, Pgingivitis. Bacterial-induced gingival low-level inflammation induced a systemic increase in inflammatory markers. Dental hygiene almost completely reversed this experimental inflammatory process, suggesting that appropriate dental prophylaxis may also limit systemic markers of inflammation in subjects with natural gingivitis. International Clinical Trials Register Platform of the World Health Organization, registry number: DRKS00003366, URL: http://apps.who.int/trialsearch/Default.aspx.

Numerical simulation of stage separation of a multi-stage flying object with brake jets

International Nuclear Information System (INIS)

Mirzaei, M.; Shadaram, A.; Nia, B.N.

2005-01-01

In this paper, separation maneuver of a two-stage supersonic flying object is numerically simulated and the influences of supersonic brake jets on separation process are discussed. The finite volume approach is used for solution of unsteady three-dimensional full Navier-Stokes equations on a moving boundary domain. In this simulation, air has considered as a calorically perfect gas and since the flow field is turbulent, two equations κ-ε model has been adopted for turbulence modeling. Shocks, expansions and their reflections have major role on flow pattern between two stages during the separation process and the maneuver is dominantly affected by the main flow and braking jets. The separation process has an unsteady nature and the separation of stages at high Mach numbers induces some aerodynamic problems that may lead to fail the next stage flight. The purpose of this research is to compute the aerodynamic loads on separated stage and, consequently, the relative distance of body components with a good accuracy. The simulation of moving boundary problem is based on moving grid strategy using remeshing method. To validate the simulation, some of the results are compared with experimental data. (author)

Experimental and simulation studies on a single pass, double duct solar air heater

Energy Technology Data Exchange (ETDEWEB)

Forson, F.K. [Kwame Nkrumah Univ. of Science and Technology, Dept. of Mechanical Engineering, Kumasi (Ghana); Rajakaruna, H. [De Montfort Univ., School of Engineering and Technology, Leicester (United Kingdom)

2003-05-01

A mathematical model of a single pass, double duct solar air heater (SPDDSAH) is described. The model provides a design tool capable of predicting: incident solar radiation, heat transfer coefficients, mean air flow rates, mean air temperature and relative humidity at the exit. Results from the simulation are presented and compared with experimental ones obtained on a full scale air heater and a small scale laboratory one. Reasonable agreement between the predicted and measured values is demonstrated. Predicted results from a parametric study are also presented. It is shown that significant improvement in the SPDDSAH performance can be obtained with an appropriate choice of the collector parameters and the top to bottom channel depth ratio of the two ducts. The air mass flow rate is shown to be the dominant factor in determining the overall efficiency of the heater. (Author)

Comparison of analytical models and experimental results for single-event upset in CMOS SRAMs

International Nuclear Information System (INIS)

Mnich, T.M.; Diehl, S.E.; Shafer, B.D.

1983-01-01

In an effort to design fully radiation-hardened memories for satellite and deep-space applications, a 16K and a 2K CMOS static RAM were modeled for single-particle upset during the design stage. The modeling resulted in the addition of a hardening feedback resistor in the 16K remained tentatively unaltered. Subsequent experiments, using the Lawrence Berkeley Laboratories' 88-inch cyclotron to accelerate krypton and oxygen ions, established an upset threshold for the 2K and the 16K without resistance added, as well as a hardening threshold for the 16K with feedback resistance added. Results for the 16K showed it to be hardenable to the higher level than previously published data for other unhardened 16K RAMs. The data agreed fairly well with the modeling results; however, a close look suggests that modification of the simulation methodology is required to accurately predict the resistance necessary to harden the RAM cell

Article mounting and position adjustment stage

Science.gov (United States)

Cutburth, Ronald W.; Silva, Leonard L.

1988-01-01

An improved adjustment and mounting stage of the type used for the detection of laser beams is disclosed. A ring sensor holder has locating pins on a first side thereof which are positioned within a linear keyway in a surrounding housing for permitting reciprocal movement of the ring along the keyway. A rotatable ring gear is positioned within the housing on the other side of the ring from the linear keyway and includes an oval keyway which drives the ring along the linear keyway upon rotation of the gear. Motor-driven single-stage and dual (x, y) stage adjustment systems are disclosed which are of compact construction and include a large laser transmission hole.

Thermodynamic simulation of condensation heat recovery characteristics of a single stage centrifugal chiller in a hotel

International Nuclear Information System (INIS)

Gong, Guangcai; Chen, Feihu; Su, Huan; Zhou, Jianyong

2012-01-01

Highlights: ► Thermodynamic model of a two-condenser condensation system has been carried out. ► Dynamic simulation method has been presented. ► COP and g of the refrigerating system is better than the single condensation system. ► The optimal parameters for the two-condenser condensation system have been studied. -- Abstract: A thermodynamic simulation study has been carried out for a single stage centrifugal chiller in this paper. The cooling capacity of the chiller unit is about 1750 kW. The chiller unit has been set and tested, and the work refrigerant is R22. A heat exchanger has been set between outlet of the compressor and the condenser for sanitary hot water supplying. Then the chiller unit is a kind of combined system that can provide sanitary hot water supplying and air conditioning simultaneously. A thermodynamic simulation model of the combined system has been established with the system simulation toolbox Simulink. Performance of the components and the combined system of the chiller unit has been studied over a wide range of operating conditions. The potential energy and fuel cost saving associated with the use of the proposed combined system for a typical hotel in south China has been estimated. It is showed that the combined system of the chiller unit is very useful in hotel buildings. And the thermodynamic simulation model of the combined system is significance for the optimization of parameters of the chiller unit such as condensation and evaporation temperature, mass flow of the sanitary hot water and size of hot water storage tank.

Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

Energy Technology Data Exchange (ETDEWEB)

Mahesh Iyer; Himanshu Gupta; Danny Wong; Liang-Shih Fan

2005-09-30

Hydrogen production from coal gasification can be enhanced by driving the equilibrium limited Water Gas Shift reaction forward by incessantly removing the CO{sub 2} by-product via the carbonation of calcium oxide. This project aims at using the OSU patented high-reactivity mesoporous precipitated calcium carbonate sorbent for removing the CO{sub 2} product. Preliminary experiments demonstrate the show the superior performance of the PCC sorbent over other naturally occurring calcium sorbents. Gas composition analyses show the formation of 100% pure hydrogen. Novel calcination techniques could lead to smaller reactor footprint and single-stage reactors that can achieve maximum theoretical H{sub 2} production for multicyclic applications. Sub-atmospheric calcination studies reveal the effect of vacuum level, diluent gas flow rate, thermal properties of the diluent gas and the sorbent loading on the calcination kinetics which play an important role on the sorbent morphology. Steam, which can be easily separated from CO{sub 2}, is envisioned to be a potential diluent gas due to its enhanced thermal properties. Steam calcination studies at 700-850 C reveal improved sorbent morphology over regular nitrogen calcination. A mixture of 80% steam and 20% CO{sub 2} at ambient pressure was used to calcine the spent sorbent at 820 C thus lowering the calcination temperature. Regeneration of calcium sulfide to calcium carbonate was achieved by carbonating the calcium sulfide slurry by bubbling CO{sub 2} gas at room temperature.

Single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation for lumbosacral brucellosis.

Science.gov (United States)

Abulizi, Yakefu; Liang, Wei-Dong; Muheremu, Aikeremujiang; Maimaiti, Maierdan; Sheng, Wei-Bin

2017-07-14

Spinal brucellosis is a less commonly reported infectious spinal pathology. There are few reports regarding the surgical treatment of spinal brucellosis in existing literature. This retrospective study was conducted to determine the effectiveness of single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation for lumbosacral spinal brucellosis. From February 2012 to April 2015, 32 consecutive patients (19 males and 13 females, mean age 53.7 ± 8.7) with lumbosacral brucellosis treated by transforaminal decompression, debridement, interbody fusion, and posterior instrumentation were enrolled. Medical records, imaging studies, laboratory data were collected and summarized. Surgical outcomes were evaluated based on visual analogue scale (VAS), Oswestry Disability Index (ODI) and Japanese Orthopaedic Association (JOA) scale. The changes in C-reactive protein (CRP) levels, erythrocyte sedimentation rate (ESR), clinical symptoms and complications were investigated. Graft fusion was evaluated using Bridwell grading criteria. The mean follow-up period was 24.9 ± 8.2 months. Back pain and radiating leg pain was relieved significantly in all patients after operation. No implant failures were observed in any patients. Wound infection was observed in two patients and sinus formation was observed in one patient. Solid bony fusion was achieved in 30 patients and the fusion rate was 93.8%. The levels of ESR and CRP were returned to normal by the end of three months' follow-up. VAS and ODI scores were significantly improved (P brucellosis.

Optimisation of thallium ''1223'' high-temperature superconducting wire by a single-stage cold deformation process. [TlPbSrCaCuO

Energy Technology Data Exchange (ETDEWEB)

Glowacki, B A [IRC in Superconductivity, Cambridge (United Kingdom) Materials Science and Metallurgy, Cambridge (United Kingdom); Ashworth, S P [BICC Cables Ltd., Erith (United Kingdom)

1992-09-15

Superconducting tapes containing (Tl[sub 0.5]Pb[sub 0.5])Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub 9] were manufactured by a powder-in-tube technique and a single annealing stage. The (Tl[sub 0.5]Pb[sub 0.5])Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub 9] forms a ''1223'' structure with a Tc of over 120 K. A cold pressing stage was found to be necessary to achieve the higher J[sub c] values at 77 K. The transport J[sub c] was found to depend on: the annealing temperature, annealing time and pressing pressure. SEM examination of the Tl-1223 grain structure showed a marked difference between rolled and pressed tapes. This is ascribed to the production of a lead-rich phase during pressing, this is supported by XRD evidence. No significant degree of grain alignment was found in the Tl-1223 tapes, either by XRD analysis or by the measurement of transport critical current in applied magnetic fields. (orig.).

Experimental demonstration of dielectric structure based two beam acceleration

International Nuclear Information System (INIS)

Gai, W.; Conde, M. E.; Konecny, R.; Power, J. G.; Schoessow, P.; Sun, X.; Zou, P.

2000-01-01

We report on the experimental results of the dielectric based two beam accelerator (step-up transformer). By using a single high charge beam, we have generated and extracted a high power RF pulse from a 7.8 GHz primary dielectric structure and then subsequently transferred to a second accelerating structure with higher dielectric constant and smaller transverse dimensions. We have measured the energy change of a second (witness) beam passing through the acceleration stage. The measured gradient is >4 times the deceleration gradient. The detailed experiment of set-up and results of the measurements are dimmed. Future plans for the development of a 100 MeV demonstration accelerator based on this technique is presented

Experimental demonstration of dielectric structure based two beam acceleration.

Energy Technology Data Exchange (ETDEWEB)

Gai, W.; Conde, M. E.; Konecny, R.; Power, J. G.; Schoessow, P.; Sun, X.; Zou, P.

2000-11-28

We report on the experimental results of the dielectric based two beam accelerator (step-up transformer). By using a single high charge beam, we have generated and extracted a high power RF pulse from a 7.8 GHz primary dielectric structure and then subsequently transferred to a second accelerating structure with higher dielectric constant and smaller transverse dimensions. We have measured the energy change of a second (witness) beam passing through the acceleration stage. The measured gradient is >4 times the deceleration gradient. The detailed experiment of set-up and results of the measurements are dimmed. Future plans for the development of a 100 MeV demonstration accelerator based on this technique is presented.

One-stage versus two-stage exchange arthroplasty for infected total knee arthroplasty: a systematic review.

Science.gov (United States)

Nagra, Navraj S; Hamilton, Thomas W; Ganatra, Sameer; Murray, David W; Pandit, Hemant

2016-10-01

Infection complicating total knee arthroplasty (TKA) has serious implications. Traditionally the debate on whether one- or two-stage exchange arthroplasty is the optimum management of infected TKA has favoured two-stage procedures; however, a paradigm shift in opinion is emerging. This study aimed to establish whether current evidence supports one-stage revision for managing infected TKA based on reinfection rates and functional outcomes post-surgery. MEDLINE/PubMed and CENTRAL databases were reviewed for studies that compared one- and two-stage exchange arthroplasty TKA in more than ten patients with a minimum 2-year follow-up. From an initial sample of 796, five cohort studies with a total of 231 patients (46 single-stage/185 two-stage; median patient age 66 years, range 61-71 years) met inclusion criteria. Overall, there were no significant differences in risk of reinfection following one- or two-stage exchange arthroplasty (OR -0.06, 95 % confidence interval -0.13, 0.01). Subgroup analysis revealed that in studies published since 2000, one-stage procedures have a significantly lower reinfection rate. One study investigated functional outcomes and reported that one-stage surgery was associated with superior functional outcomes. Scarcity of data, inconsistent study designs, surgical technique and antibiotic regime disparities limit recommendations that can be made. Recent studies suggest one-stage exchange arthroplasty may provide superior outcomes, including lower reinfection rates and superior function, in select patients. Clinically, for some patients, one-stage exchange arthroplasty may represent optimum treatment; however, patient selection criteria and key components of surgical and post-operative anti-microbial management remain to be defined. III.

Multi-stage decoding of multi-level modulation codes

Science.gov (United States)

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

1991-01-01

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

Bacterial community dynamics during the early stages of biofilm formation in a chlorinated experimental drinking water distribution system: implications for drinking water discolouration.

Science.gov (United States)

Douterelo, I; Sharpe, R; Boxall, J

2014-07-01

To characterize bacterial communities during the early stages of biofilm formation and their role in water discolouration in a fully representative, chlorinated, experimental drinking water distribution systems (DWDS). Biofilm development was monitored in an experimental DWDS over 28 days; subsequently the system was disturbed by raising hydraulic conditions to simulate pipe burst, cleaning or other system conditions. Biofilm cell cover was monitored by fluorescent microscopy and a fingerprinting technique used to assess changes in bacterial community. Selected samples were analysed by cloning and sequencing of the 16S rRNA gene. Fingerprinting analysis revealed significant changes in the bacterial community structure over time (P < 0·05). Cell coverage increased over time accompanied by an increase in bacterial richness and diversity. Shifts in the bacterial community structure were observed along with an increase in cell coverage, bacterial richness and diversity. Species related to Pseudomonas spp. and Janthinobacterium spp. dominated the process of initial attachment. Based on fingerprinting results, the hydraulic regimes did not affect the bacteriological composition of biofilms, but they did influence their mechanical stability. This study gives a better insight into the early stages of biofilm formation in DWDS and will contribute to the improvement of management strategies to control the formation of biofilms and the risk of discolouration. © 2014 The Authors. published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.

Bacterial community dynamics during the early stages of biofilm formation in a chlorinated experimental drinking water distribution system: implications for drinking water discolouration

Science.gov (United States)

Douterelo, I; Sharpe, R; Boxall, J

2014-01-01

Aims To characterize bacterial communities during the early stages of biofilm formation and their role in water discolouration in a fully representative, chlorinated, experimental drinking water distribution systems (DWDS). Methods and Results Biofilm development was monitored in an experimental DWDS over 28 days; subsequently the system was disturbed by raising hydraulic conditions to simulate pipe burst, cleaning or other system conditions. Biofilm cell cover was monitored by fluorescent microscopy and a fingerprinting technique used to assess changes in bacterial community. Selected samples were analysed by cloning and sequencing of the 16S rRNA gene. Fingerprinting analysis revealed significant changes in the bacterial community structure over time (P < 0·05). Cell coverage increased over time accompanied by an increase in bacterial richness and diversity. Conclusions Shifts in the bacterial community structure were observed along with an increase in cell coverage, bacterial richness and diversity. Species related to Pseudomonas spp. and Janthinobacterium spp. dominated the process of initial attachment. Based on fingerprinting results, the hydraulic regimes did not affect the bacteriological composition of biofilms, but they did influence their mechanical stability. Significance and Importance of the Study This study gives a better insight into the early stages of biofilm formation in DWDS and will contribute to the improvement of management strategies to control the formation of biofilms and the risk of discolouration. PMID:24712449

Automatic sleep stage classification using two facial electrodes.

Science.gov (United States)

Virkkala, Jussi; Velin, Riitta; Himanen, Sari-Leena; Värri, Alpo; Müller, Kiti; Hasan, Joel

2008-01-01

Standard sleep stage classification is based on visual analysis of central EEG, EOG and EMG signals. Automatic analysis with a reduced number of sensors has been studied as an easy alternative to the standard. In this study, a single-channel electro-oculography (EOG) algorithm was developed for separation of wakefulness, SREM, light sleep (S1, S2) and slow wave sleep (S3, S4). The algorithm was developed and tested with 296 subjects. Additional validation was performed on 16 subjects using a low weight single-channel Alive Monitor. In the validation study, subjects attached the disposable EOG electrodes themselves at home. In separating the four stages total agreement (and Cohen's Kappa) in the training data set was 74% (0.59), in the testing data set 73% (0.59) and in the validation data set 74% (0.59). Self-applicable electro-oculography with only two facial electrodes was found to provide reasonable sleep stage information.

Stages of Ovarian Epithelial, Fallopian Tube, and Primary Peritoneal Cancer

Science.gov (United States)

... diagnosed, tests are done to find out if cancer cells have spread within the ovaries or to other parts of the body. The ... single ovary or fallopian tube. In stage IB, cancer is found inside both ovaries or fallopian tubes. In stage IC, cancer is ...

Dose rate distribution for products irradiated in a semi-industrial irradiation plant. 1st stage

International Nuclear Information System (INIS)

Mangussi, J.

2005-01-01

The model of the bulk product absorbed dose rate distribution in a semi industrial irradiation plant is presented. In this plant the products are subject to a dynamic irradiation process: single-plaque, single-direction, four-passes. The additional two passes, also one on each side of the plaque, serve to minimize the lateral dose variation as well as the depth-dose non-uniformity. The first stage of this model takes only into account the direct absorbed dose rate; the model outputs are the depth-dose distribution and the lateral-dose distribution. The calculated absorbed dose in the bulk product and its uniformity-ratio after the dynamic irradiation process for different products is compared. The model results are in good agreement with the experimental measurements in a bulk of irradiated product; and the air absorbed dose rate in the irradiation chamber behind the product subject to the dynamic irradiation process. (author) [es

Experimental investigation of saturation effect on pump-to-signal intensity modulation transfer in single-pump phase-insensitive fiber optic parametric amplifiers

DEFF Research Database (Denmark)

Cristofori, Valentina; Lali-Dastjerdi, Zohreh; Lund-Hansen, Toke

2013-01-01

We present an experimental characterization of how signal gain saturation affects the transfer of intensity modulation from the pump to the signal in single-pump, phase-insensitive fiber optic parametric amplifiers (FOPAs). In this work, we demonstrate experimentally for the first time, to our...... knowledge, how gain saturation of a FOPA reduces the noise contribution due to the transfer of pump power fluctuations to the signal. In a particular example, it is shown that the transferred noise is significantly reduced by a factor of 3, while the FOPA gain remains above 10 dB....

A novel flow sensor based on resonant sensing with two-stage microleverage mechanism

Science.gov (United States)

Yang, B.; Guo, X.; Wang, Q. H.; Lu, C. F.; Hu, D.

2018-04-01

The design, simulation, fabrication, and experiments of a novel flow sensor based on resonant sensing with a two-stage microleverage mechanism are presented in this paper. Different from the conventional detection methods for flow sensors, two differential resonators are adopted to implement air flow rate transformation through two-stage leverage magnification. The proposed flow sensor has a high sensitivity since the adopted two-stage microleverage mechanism possesses a higher amplification factor than a single-stage microleverage mechanism. The modal distribution and geometric dimension of the two-stage leverage mechanism and hair are analyzed and optimized by Ansys simulation. A digital closed-loop driving technique with a phase frequency detector-based coordinate rotation digital computer algorithm is implemented for the detection and locking of resonance frequency. The sensor fabricated by the standard deep dry silicon on a glass process has a device dimension of 5100 μm (length) × 5100 μm (width) × 100 μm (height) with a hair diameter of 1000 μm. The preliminary experimental results demonstrate that the maximal mechanical sensitivity of the flow sensor is approximately 7.41 Hz/(m/s)2 at a resonant frequency of 22 kHz for the hair height of 9 mm and increases by 2.42 times as hair height extends from 3 mm to 9 mm. Simultaneously, a detection-limit of 3.23 mm/s air flow amplitude at 60 Hz is confirmed. The proposed flow sensor has great application prospects in the micro-autonomous system and technology, self-stabilizing micro-air vehicles, and environmental monitoring.

Posterior tibial tendon insufficiency results at different stages.

Science.gov (United States)

Deland, Jonathan T; Page, Alexandra; Sung, Il-Hoon; O'Malley, Martin J; Inda, David; Choung, Steven

2006-09-01

The results of surgical treatment of posterior tibial tendon insufficiency (PTTI) may be different at different stages of the disease. No single study has compared the results at different stages. This comparison can be helpful to the patient and physician if the patient asks "What if I wait and the disease progresses, how will my results be different?" A preliminary study comparing results for stage IIa, stage IIb (advanced stage II), and stage III was performed followed by a larger study comparing IIa and IIb with 26 and 22 patients, respectively. American Orthopaedic Foot and Ankle Society (AOFAS) outcome scores as well as radiographs and functional questions were used. Nearly all patients, regardless of stage, felt they were helped by surgical treatment. However, the lowest AOFAS score was in stage III, the most advanced stage investigated in this study. In comparing stage IIa and IIb patients, stage IIb patients had a statistically higher incidence of lateral discomfort. Although statistically significant differences were not found in all comparisons, this study suggests that the results of surgical treatment for PTTI declines with increasing stage or severity of disease.

Comparative effectiveness of one-stage versus two-stage basilic vein transposition arteriovenous fistulas.

Science.gov (United States)

Ghaffarian, Amir A; Griffin, Claire L; Kraiss, Larry W; Sarfati, Mark R; Brooke, Benjamin S

2018-02-01

Basilic vein transposition (BVT) fistulas may be performed as either a one-stage or two-stage operation, although there is debate as to which technique is superior. This study was designed to evaluate the comparative clinical efficacy and cost-effectiveness of one-stage vs two-stage BVT. We identified all patients at a single large academic hospital who had undergone creation of either a one-stage or two-stage BVT between January 2007 and January 2015. Data evaluated included patient demographics, comorbidities, medication use, reasons for abandonment, and interventions performed to maintain patency. Costs were derived from the literature, and effectiveness was expressed in quality-adjusted life-years (QALYs). We analyzed primary and secondary functional patency outcomes as well as survival during follow-up between one-stage and two-stage BVT procedures using multivariate Cox proportional hazards models and Kaplan-Meier analysis with log-rank tests. The incremental cost-effectiveness ratio was used to determine cost savings. We identified 131 patients in whom 57 (44%) one-stage BVT and 74 (56%) two-stage BVT fistulas were created among 8 different vascular surgeons during the study period that each performed both procedures. There was no significant difference in the mean age, male gender, white race, diabetes, coronary disease, or medication profile among patients undergoing one- vs two-stage BVT. After fistula transposition, the median follow-up time was 8.3 months (interquartile range, 3-21 months). Primary patency rates of one-stage BVT were 56% at 12-month follow-up, whereas primary patency rates of two-stage BVT were 72% at 12-month follow-up. Patients undergoing two-stage BVT also had significantly higher rates of secondary functional patency at 12 months (57% for one-stage BVT vs 80% for two-stage BVT) and 24 months (44% for one-stage BVT vs 73% for two-stage BVT) of follow-up (P < .001 using log-rank test). However, there was no significant difference

Preoperative Single Fraction Partial Breast Radiotherapy for Early-Stage Breast Cancer

Energy Technology Data Exchange (ETDEWEB)

Palta, Manisha; Yoo, Sua; Adamson, Justus D.; Prosnitz, Leonard R. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Horton, Janet K., E-mail: janet.horton@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

2012-01-01

Purpose: Several recent series evaluating external beam accelerated partial breast irradiation (PBI) have reported adverse cosmetic outcomes, possibly related to large volumes of normal tissue receiving near-prescription doses. We hypothesized that delivery of external beam PBI in a single fraction to the preoperative tumor volume would be feasible and result in a decreased dose to the uninvolved breast compared with institutional postoperative PBI historical controls. Methods and Materials: A total of 17 patients with unifocal Stage T1 breast cancer were identified. Contrast-enhanced subtraction magnetic resonance images were loaded into an Eclipse treatment planning system and used to define the target volumes. A 'virtual plan' was created using four photon beams in a noncoplanar beam arrangement and optimized to deliver 15 Gy to the planning target volume. Results: The median breast volume was 1,713 cm{sup 3} (range: 1,014-2,140), and the median clinical target volume was 44 cm{sup 3} (range: 26-73). In all cases, 100% of the prescription dose covered 95% of the clinical target volume. The median conformity index was 0.86 (range: 0.70-1.12). The median percentage of the ipsilateral breast volume receiving 100% and 50% of the prescribed dose was 3.8% (range: 2.2-6.9) and 13.3% (range: 7.5-20.8) compared with 18% (range: 3-42) and 53% (range: 24-65) in the institutional historical controls treated with postoperative external beam PBI (p = .002). The median maximum skin dose was 9 Gy. The median dose to 1 and 10 cm{sup 3} of skin was 6.7 and 4.9 Gy. The doses to the heart and ipsilateral lung were negligible. Conclusion: Preoperative PBI resulted in a substantial reduction in ipsilateral breast tissue dose compared with postoperative PBI. The skin dose appeared reasonable, given the small volumes. A prospective Phase I trial evaluating this technique is ongoing.

Preoperative single fraction partial breast radiotherapy for early-stage breast cancer.

Science.gov (United States)

Palta, Manisha; Yoo, Sua; Adamson, Justus D; Prosnitz, Leonard R; Horton, Janet K

2012-01-01

Several recent series evaluating external beam accelerated partial breast irradiation (PBI) have reported adverse cosmetic outcomes, possibly related to large volumes of normal tissue receiving near-prescription doses. We hypothesized that delivery of external beam PBI in a single fraction to the preoperative tumor volume would be feasible and result in a decreased dose to the uninvolved breast compared with institutional postoperative PBI historical controls. A total of 17 patients with unifocal Stage T1 breast cancer were identified. Contrast-enhanced subtraction magnetic resonance images were loaded into an Eclipse treatment planning system and used to define the target volumes. A "virtual plan" was created using four photon beams in a noncoplanar beam arrangement and optimized to deliver 15 Gy to the planning target volume. The median breast volume was 1,713 cm(3) (range: 1,014-2,140), and the median clinical target volume was 44 cm(3) (range: 26-73). In all cases, 100% of the prescription dose covered 95% of the clinical target volume. The median conformity index was 0.86 (range: 0.70-1.12). The median percentage of the ipsilateral breast volume receiving 100% and 50% of the prescribed dose was 3.8% (range: 2.2-6.9) and 13.3% (range: 7.5-20.8) compared with 18% (range: 3-42) and 53% (range: 24-65) in the institutional historical controls treated with postoperative external beam PBI (p = .002). The median maximum skin dose was 9 Gy. The median dose to 1 and 10 cm(3) of skin was 6.7 and 4.9 Gy. The doses to the heart and ipsilateral lung were negligible. Preoperative PBI resulted in a substantial reduction in ipsilateral breast tissue dose compared with postoperative PBI. The skin dose appeared reasonable, given the small volumes. A prospective Phase I trial evaluating this technique is ongoing. Copyright © 2012 Elsevier Inc. All rights reserved.

Preoperative Single Fraction Partial Breast Radiotherapy for Early-Stage Breast Cancer

International Nuclear Information System (INIS)

Palta, Manisha; Yoo, Sua; Adamson, Justus D.; Prosnitz, Leonard R.; Horton, Janet K.

2012-01-01

Purpose: Several recent series evaluating external beam accelerated partial breast irradiation (PBI) have reported adverse cosmetic outcomes, possibly related to large volumes of normal tissue receiving near-prescription doses. We hypothesized that delivery of external beam PBI in a single fraction to the preoperative tumor volume would be feasible and result in a decreased dose to the uninvolved breast compared with institutional postoperative PBI historical controls. Methods and Materials: A total of 17 patients with unifocal Stage T1 breast cancer were identified. Contrast-enhanced subtraction magnetic resonance images were loaded into an Eclipse treatment planning system and used to define the target volumes. A “virtual plan” was created using four photon beams in a noncoplanar beam arrangement and optimized to deliver 15 Gy to the planning target volume. Results: The median breast volume was 1,713 cm 3 (range: 1,014–2,140), and the median clinical target volume was 44 cm 3 (range: 26–73). In all cases, 100% of the prescription dose covered 95% of the clinical target volume. The median conformity index was 0.86 (range: 0.70–1.12). The median percentage of the ipsilateral breast volume receiving 100% and 50% of the prescribed dose was 3.8% (range: 2.2–6.9) and 13.3% (range: 7.5–20.8) compared with 18% (range: 3–42) and 53% (range: 24–65) in the institutional historical controls treated with postoperative external beam PBI (p = .002). The median maximum skin dose was 9 Gy. The median dose to 1 and 10 cm 3 of skin was 6.7 and 4.9 Gy. The doses to the heart and ipsilateral lung were negligible. Conclusion: Preoperative PBI resulted in a substantial reduction in ipsilateral breast tissue dose compared with postoperative PBI. The skin dose appeared reasonable, given the small volumes. A prospective Phase I trial evaluating this technique is ongoing.

Investigations into the operating behavior of separation nozzle cascades for uranium-235 enrichment in a 10-stage pilot plant

International Nuclear Information System (INIS)

Bley, P.; Hein, H.; Linder, G.

1984-03-01

The separation nozzle method developed by the Karlsruhe Nuclear Research Center is based on the centrifugal force in a curved jet consisting of uranium hexafluoride and a light auxiliary gas. To determine in experiments the operating and controlling behavior of separation nozzle cascades a 10-stage pilot plant was erected some year ago. This plant was transferred to the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) in Belo Horizonte as a donation made within the framework of the German-Brazilian Agreement on scientific cooperation in the field of uranium enrichment. The plant previously equipped with single deflection systems was modified to operate with the double deflection system envisaged for commercial plants. A controlling concept meanwhile developed and improved for separation nozzle cascades equipped with single and double deflection systems was verified experimentally and optimized at the pilot plant of the CDTN. A comparison of the experimental operating behavior with the operating behavior calculated by simulation programs has confirmed the faithfulness of simulation of the computer codes developed to apply to cascades with double deflection systems as well. (orig.) [de

Stages as models of scene geometry.

Science.gov (United States)

Nedović, Vladimir; Smeulders, Arnold W M; Redert, André; Geusebroek, Jan-Mark

2010-09-01

Reconstruction of 3D scene geometry is an important element for scene understanding, autonomous vehicle and robot navigation, image retrieval, and 3D television. We propose accounting for the inherent structure of the visual world when trying to solve the scene reconstruction problem. Consequently, we identify geometric scene categorization as the first step toward robust and efficient depth estimation from single images. We introduce 15 typical 3D scene geometries called stages, each with a unique depth profile, which roughly correspond to a large majority of broadcast video frames. Stage information serves as a first approximation of global depth, narrowing down the search space in depth estimation and object localization. We propose different sets of low-level features for depth estimation, and perform stage classification on two diverse data sets of television broadcasts. Classification results demonstrate that stages can often be efficiently learned from low-dimensional image representations.

S4 Grid-Connected Single-Phase Transformerless Inverter for PV Application

DEFF Research Database (Denmark)

Ardashir, Jaber Fallah; Siwakoti, Yam Prasad; Sabahi, Mehran

2016-01-01

This paper introduces a new single-phase transformerless inverter for grid-connected photovoltaic systems with low leakage current. It consists of four power switches, two diodes, two capacitors and a filter at the output stage. The neutral of the grid is directly connected to the negative terminal...... size, low cost, flexible grounding configuration and higher efficiency. The operating principle and analysis of the proposed circuit are presented in details. Experimental results of a 500 W prototype are demonstrated to validate the proposed topology and the overall concept. The results obtained...... clearly verify the performance of the proposed inverter and its practical application for grid-connected PV systems....

Numerical and experimental study of a solid pellet feed continuous Czochralski growth process for silicon single crystals

Science.gov (United States)

Anselmo, A.; Prasad, V.; Koziol, J.; Gupta, K. P.

1993-07-01

A polysilicon pellets (≅1 mm diameter) feed continuous Czochralski (CCZ) growth process for silicon single crystals is proposed and investigated. Experiments in an industrial puller (14-18 inch diameter crucible) successfully demonstrate the feasibility of this process. The advantages of the proposed scheme are: a steady state growth process, a low aspect ratio melt, uniformity of heat addition and a growth apparatus with single crucible and no baffle(s). The addition of dopant with the solid charge will allow a better control of oxygen concentration leading to crystals of uniform properties and better quality. This paper presents theoretical results on melting of fully and partially immersed silicon spheres and numerical solutions on temperature and flow fields in low aspect ration melts with and without the addition of solid pellets. The theoretical and experimental results obtained thus far show a great promise for the proposed scheme.