A Sequential Fluid-mechanic Chemical-kinetic Model of Propane HCCI Combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aceves, S M; Flowers, D L; Martinez-Frias, J

2000-11-29

We have developed a methodology for predicting combustion and emissions in a Homogeneous Charge Compression Ignition (HCCI) Engine. This methodology combines a detailed fluid mechanics code with a detailed chemical kinetics code. Instead of directly linking the two codes, which would require an extremely long computational time, the methodology consists of first running the fluid mechanics code to obtain temperature profiles as a function of time. These temperature profiles are then used as input to a multi-zone chemical kinetics code. The advantage of this procedure is that a small number of zones (10) is enough to obtain accurate results. Thismore » procedure achieves the benefits of linking the fluid mechanics and the chemical kinetics codes with a great reduction in the computational effort, to a level that can be handled with current computers. The success of this procedure is in large part a consequence of the fact that for much of the compression stroke the chemistry is inactive and thus has little influence on fluid mechanics and heat transfer. Then, when chemistry is active, combustion is rather sudden, leaving little time for interaction between chemistry and fluid mixing and heat transfer. This sequential methodology has been capable of explaining the main characteristics of HCCI combustion that have been observed in experiments. In this paper, we use our model to explore an HCCI engine running on propane. The paper compares experimental and numerical pressure traces, heat release rates, and hydrocarbon and carbon monoxide emissions. The results show an excellent agreement, even in parameters that are difficult to predict, such as chemical heat release rates. Carbon monoxide emissions are reasonably well predicted, even though it is intrinsically difficult to make good predictions of CO emissions in HCCI engines. The paper includes a sensitivity study on the effect of the heat transfer correlation on the results of the analysis. Importantly, the paper also shows a numerical study on how parameters such as swirl rate, crevices and ceramic walls could help in reducing HC and CO emissions from HCCI engines.« less

Variable Valve Actuation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeffrey Gutterman; A. J. Lasley

2008-08-31

Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation ismore » a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the mechanism it was determined that the single cam design did not have enough flexibility to satisfy three critical OEM requirements simultaneously, (maximum valve lift variation, intake valve opening timing and valve closing duration), and a new approach would be necessary. After numerous internal design reviews including several with the OEM a dual cam design was developed that had the flexibility to meet all motion requirements. The second cam added complexity to the mechanism however the cost was offset by the deletion of the electric motor required in the previous design. New patent applications including detailed drawings and potential valve motion profiles were generated and alternate two cam designs were proposed and evaluated for function, cost, reliability and durability. Hardware was designed and built and testing of sample hardware was successfully completed on an engine test stand. The mechanism developed during the course of this investigation can be applied by Original Equipment Manufacturers, (OEM), to their advanced diesel engines with the ultimate goal of reducing emissions and improving fuel economy. The objectives are: (1) Develop an optimal, cost effective, variable valve actuation (VVA) system for advanced low temperature diesel combustion processes. (2) Design and model alternative mechanical approaches and down-select for optimum design. (3) Build and demonstrate a mechanism capable of application on running engines.« less

On the influence of singlet oxygen molecules on characteristics of HCCI combustion: A numerical study

NASA Astrophysics Data System (ADS)

Starik, A. M.; Kozlov, V. E.; Titova, N. S.

2013-08-01

Mechanisms of homogeneous charge compression ignition (HCCI) combustion enhancement are investigated numerically when excited O2(a 1Δg) molecules are produced at different points in the compression stroke. The analysis is conducted with the use of an extended kinetic model involving the submechanism of nitric oxide formation in the presence of singlet oxygen O2(a 1Δg) or O2(b 1Σg +) molecules in the methane-air mixture. It is demonstrated that the abundance of excited O2(a 1Δg) molecules in the mixture even in a small amounts intensifies the ignition and combustion and allows one to control the ignition event in the HCCI engine. Such a method of energy supply in the HCCI engine is much more effective in advancement of combustion timing than mere heating of the mixture, because it leads to acceleration of the chain-branching mechanism. The excitation of O2 molecules to the a 1Δg electronic state makes it possible to organise the successful combustion in the cylinder at diminished initial temperature of the mixture and increase the effective energy released during HCCI combustion. The advance in the value of this energy is much higher than the energy needed for the excitation of oxygen molecules. Moreover, in this case, the output concentration of NO and CO can be reduced significantly.

Investigation of spray characteristics from a low-pressure common rail injector for use in a homogeneous charge compression ignition engine

NASA Astrophysics Data System (ADS)

Lee, Kihyung; Reitz, Rolf D.

2004-03-01

Homogeneous charge compression ignition (HCCI) combustion provides extremely low levels of pollutant emissions, and thus is an attractive alternative for future IC engines. In order to achieve a uniform mixture distribution within the engine cylinder, the characteristics of the fuel spray play an important role in the HCCI engine concept. It is well known that high-pressure common rail injection systems, mainly used in diesel engines, achieve poor mixture formation because of the possibility of direct fuel impingement on the combustion chamber surfaces. This paper describes spray characteristics of a low-pressure common rail injector which is intended for use in an HCCI engine. Optical diagnostics including laser diffraction and phase Doppler methods, and high-speed camera photography, were applied to measure the spray drop diameter and to investigate the spray development process. The drop sizing results of the laser diffraction method were compared with those of a phase Doppler particle analyser (PDPA) to validate the accuracy of the experiments. In addition, the effect of fuel properties on the spray characteristics was investigated using n-heptane, Stoddard solvent (gasoline surrogate) and diesel fuel because HCCI combustion is sensitive to the fuel composition. The results show that the injector forms a hollow-cone sheet spray rather than a liquid jet, and the atomization efficiency is high (small droplets are produced). The droplet SMD ranged from 15 to 30 µm. The spray break-up characteristics were found to depend on the fuel properties. The break-up time for n-heptane is shorter and the drop SMD is smaller than that of Stoddard solvent and diesel fuel.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalaskar, Vickey B; Szybist, James P; Splitter, Derek A

In recent years a number of studies have demonstrated that boosted operation combined with external EGR is a path forward for expanding the high load limit of homogeneous charge compression ignition (HCCI) operation with the negative valve overlap (NVO) valve strategy. However, the effects of fuel composition with this strategy have not been fully explored. In this study boosted HCCI combustion is investigated in a single-cylinder research engine equipped with direct injection (DI) fueling, cooled external exhaust gas recirculation (EGR), laboratory pressurized intake air, and a fully-variable hydraulic valve actuation (HVA) valve train. Three fuels with significant compositional differences aremore » investigated: regular grade gasoline (RON = 90.2), 30% ethanol-gasoline blend (E30, RON = 100.3), and 24% iso-butanol-gasoline blend (IB24, RON = 96.6). Results include engine loads from 350 to 800 kPa IMEPg for all fuels at three engine speeds 1600, 2000, and 2500 rpm. All operating conditions achieved thermal efficiency (gross indicated efficiency) between 38 and 47%, low NOX emissions ( 0.1 g/kWh), and high combustion efficiency ( 96.5%). Detailed sweeps of intake manifold pressure (atmospheric to 250 kPaa), EGR (0 25% EGR), and injection timing are conducted to identify fuel-specific effects. The major finding of this study is that while significant fuel compositional differences exist, in boosted HCCI operation only minor changes in operational conditions are required to achieve comparable operation for all fuels. In boosted HCCI operation all fuels were able to achieve matched load-speed operation, whereas in conventional SI operation the fuel-specific knock differences resulted in significant differences in the operable load-speed space. Although all fuels were operable in boosted HCCI, the respective air handling requirements are also discussed, including an analysis of the demanded turbocharger efficiency.« less

Real-time, adaptive machine learning for non-stationary, near chaotic gasoline engine combustion time series.

PubMed

Vaughan, Adam; Bohac, Stanislav V

2015-10-01

Fuel efficient Homogeneous Charge Compression Ignition (HCCI) engine combustion timing predictions must contend with non-linear chemistry, non-linear physics, period doubling bifurcation(s), turbulent mixing, model parameters that can drift day-to-day, and air-fuel mixture state information that cannot typically be resolved on a cycle-to-cycle basis, especially during transients. In previous work, an abstract cycle-to-cycle mapping function coupled with ϵ-Support Vector Regression was shown to predict experimentally observed cycle-to-cycle combustion timing over a wide range of engine conditions, despite some of the aforementioned difficulties. The main limitation of the previous approach was that a partially acasual randomly sampled training dataset was used to train proof of concept offline predictions. The objective of this paper is to address this limitation by proposing a new online adaptive Extreme Learning Machine (ELM) extension named Weighted Ring-ELM. This extension enables fully causal combustion timing predictions at randomly chosen engine set points, and is shown to achieve results that are as good as or better than the previous offline method. The broader objective of this approach is to enable a new class of real-time model predictive control strategies for high variability HCCI and, ultimately, to bring HCCI's low engine-out NOx and reduced CO2 emissions to production engines. Copyright © 2015 Elsevier Ltd. All rights reserved.

DOE Light Truck Clean Diesel (LTCD) Program Final Caterpillar Public Report Light Truck Clean Diesel Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eric Fluga

The US Department of Energy and Caterpillar entered a Cooperative Agreement to develop compression ignition engine technology suitable for the light truck/SUV market. Caterpillar, in collaboration with a suitable commercialization partner, developed a new Compression Ignition Direct Injection (CIDI) engine technology to dramatically improve the emissions and performance of light truck engines. The overall program objective was to demonstrate engine prototypes by 2004, with an order of magnitude emission reduction while meeting challenging fuel consumption goals. Program emphasis was placed on developing and incorporating cutting edge technologies that could remove the current impediments to commercialization of CIDI power sources inmore » light truck applications. The major obstacle to commercialization is emissions regulations with secondary concerns of driveability and NVH (noise, vibration and harshness). The target emissions levels were 0.05 g/mile NOx and 0.01 g/mile PM to be compliant with the EPA Tier 2 fleet average requirements of 0.07 g/mile and the CARB LEV 2 of 0.05 g/mile for NOx, both have a PM requirement of 0.01 g/mile. The program team developed a combustion process that fundamentally shifted the classic NOx vs. PM behavior of CIDI engines. The NOx vs. PM shift was accomplished with a form of Homogeneous Charge Compression Ignition (HCCI). The HCCI concept centers on appropriate mixing of air and fuel in the compression process and controlling the inception and rate of combustion through various means such as variable valve timing, inlet charge temperature and pressure control. Caterpillar has adapted an existing Caterpillar design of a single injector that: (1) creates the appropriate fuel and air mixture for HCCI, (2) is capable of a more conventional injection to overcome the low power density problems of current HCCI implementations, (3) provides a mixed mode where both the HCCI and conventional combustion are functioning in the same combustion cycle. Figure 1 illustrates the mixed mode injection system. Under the LTCD program Caterpillar developed a mixed mode injector for a multi-cylinder engine system. The mixed mode injection system represents a critical enabling technology for the implementation of HCCI. In addition, Caterpillar implemented variable valve system technology and air system technology on the multi-cylinder engine platform. The valve and air system technology were critical to system control. Caterpillar developed the combustion system to achieve a 93% reduction in NOx emissions. The resulting NOx emissions were 0.12 gm/mile NOx. The demonstrated emissions level meets the stringent Tier 2 Bin 8 requirement without NOx aftertreatment! However, combustion development alone was not adequate to meet the program goal of 0.05gm/mile NOx. To meet the program goals, an additional 60% NOx reduction technology will be required. Caterpillar evaluated a number of NOx reduction technologies to quantify and understand the NOx reduction potential and system performance implications. The NOx adsorber was the most attractive NOx aftertreatment option based on fuel consumption and NOx reduction potential. In spite of the breakthrough technology development conducted under the LTCD program there remains many significant challenges associated with the technology configuration. For HCCI, additional effort is needed to develop a robust control strategy, reduce the hydrocarbon emissions at light load condition, and develop a more production viable fuel system. Furthermore, the NOx adsorber suffers from cost, packaging, and durability challenges that must be addressed.« less

Fundamental Interactions in Gasoline Compression Ignition Engines with Fuel Stratification

NASA Astrophysics Data System (ADS)

Wolk, Benjamin Matthew

Transportation accounted for 28% of the total U.S. energy demand in 2011, with 93% of U.S. transportation energy coming from petroleum. The large impact of the transportation sector on global climate change necessitates more-efficient, cleaner-burning internal combustion engine operating strategies. One such strategy that has received substantial research attention in the last decade is Homogeneous Charge Compression Ignition (HCCI). Although the efficiency and emissions benefits of HCCI are well established, practical limits on the operating range of HCCI engines have inhibited their application in consumer vehicles. One such limit is at high load, where the pressure rise rate in the combustion chamber becomes excessively large. Fuel stratification is a potential strategy for reducing the maximum pressure rise rate in HCCI engines. The aim is to introduce reactivity gradients through fuel stratification to promote sequential auto-ignition rather than a bulk-ignition, as in the homogeneous case. A gasoline-fueled compression ignition engine with fuel stratification is termed a Gasoline Compression Ignition (GCI) engine. Although a reasonable amount of experimental research has been performed for fuel stratification in GCI engines, a clear understanding of how the fundamental in-cylinder processes of fuel spray evaporation, mixing, and heat release contribute to the observed phenomena is lacking. Of particular interest is gasoline's pressure sensitive low-temperature chemistry and how it impacts the sequential auto-ignition of the stratified charge. In order to computationally study GCI with fuel stratification using three-dimensional computational fluid dynamics (CFD) and chemical kinetics, two reduced mechanisms have been developed. The reduced mechanisms were developed from a large, detailed mechanism with about 1400 species for a 4-component gasoline surrogate. The two versions of the reduced mechanism developed in this work are: (1) a 96-species version and (2) a 98-species version including nitric oxide formation reactions. Development of reduced mechanisms is necessary because the detailed mechanism is computationally prohibitive in three-dimensional CFD and chemical kinetics simulations. Simulations of Partial Fuel Stratification (PFS), a GCI strategy, have been performed using CONVERGE with the 96-species reduced mechanism developed in this work for a 4-component gasoline surrogate. Comparison is made to experimental data from the Sandia HCCI/GCI engine at a compression ratio 14:1 at intake pressures of 1 bar and 2 bar. Analysis of the heat release and temperature in the different equivalence ratio regions reveals that sequential auto-ignition of the stratified charge occurs in order of increasing equivalence ratio for 1 bar intake pressure and in order of decreasing equivalence ratio for 2 bar intake pressure. Increased low- and intermediate-temperature heat release with increasing equivalence ratio at 2 bar intake pressure compensates for decreased temperatures in higher-equivalence ratio regions due to evaporative cooling from the liquid fuel spray and decreased compression heating from lower values of the ratio of specific heats. The presence of low- and intermediate-temperature heat release at 2 bar intake pressure alters the temperature distribution of the mixture stratification before hot-ignition, promoting the desired sequential auto-ignition. At 1 bar intake pressure, the sequential auto-ignition occurs in the reverse order compared to 2 bar intake pressure and too fast for useful reduction of the maximum pressure rise rate compared to HCCI. Additionally, the premixed portion of the charge auto-ignites before the highest-equivalence ratio regions. Conversely, at 2 bar intake pressure, the premixed portion of the charge auto-ignites last, after the higher-equivalence ratio regions. More importantly, the sequential auto-ignition occurs over a longer time period for 2 bar intake pressure than at 1 bar intake pressure such that a sizable reduction in the maximum pressure rise rate compared to HCCI can be achieved.

Characterization of Engine Control Authority on HCCI Combustion as the High Load Limit is Approached

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szybist, James P; Edwards, Kevin Dean; Foster, Matthew

2013-01-01

While the potential emissions and efficiency benefits of homogeneous charge compression ignition (HCCI) combustion are well known, realizing the potentials on a production intent engine presents numerous challenges. In this study we focus on characterizing the authority of the available engine controls as the high load limit of HCCI combustion is approached. The experimental work is performed on a boosted single-cylinder research engine equipped with direct injection (DI) fueling, cooled external exhaust gas recirculation (EGR), and a hydraulic valve actuation (HVA) valve train to enable the negative valve overlap (NVO) breathing strategy. Valve lift and duration are held constant whilemore » phasing is varied in an effort to make the results as relevant as possible to production intent cam-based variable valve actuation (VVA) systems on multi-cylinder engines. Results presented include engine loads from 350 to 650 kPa IMEPnet and manifold pressure from 98 to 190 kPaa at 2000 rpm. It is found that in order to increase engine load to 650 kPa IMEPnet, it is necessary to increase manifold pressure and external EGR while reducing the NVO duration. Both NVO duration and fuel injection timing are effective means of controlling combustion phasing, with NVO duration being a coarse control and fuel injection timing being a fine control. NOX emissions are low throughout the study, with emissions below 0.1 g/kW-h at all boosted HCCI conditions, while good combustion efficiency is maintained (>96.5%). Net indicated thermal efficiency increases with load up to 600 kPa IMEPnet, where a peak efficiency of 41% is achieved. Results of independent parametric investigations are presented on the effect of external EGR, intake effect of manifold pressure, and the effect of NVO duration. It is found that increasing EGR at a constant manifold pressure and increasing manifold pressure at a constant EGR rate both have the effect of retarding combustion phasing. It is also found that combustion phasing becomes increasingly sensitive to NVO duration as engine load increases. Finally, comparisons are made between three commonly used noise metrics (AVL noise meter, ringing intensity (RI), and maximum pressure rise rate (MPRR)). It is found that compared to the AVL noise meter, RI significantly underestimates combustion noise under boosted conditions.« less

Fuel Composition Effects at Constant RON and MON in an HCCI Engine Operated with Negative Valve Overlap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bunting, Bruce G; Farrell, John T

2006-01-01

The effects of fuel properties on gasoline HCCI operation have been investigated in a single cylinder, 500 cc, 11.3 CR port fuel injected research engine, operated at lambda=1 and equipped with hydraulic valve actuation. HCCI is promoted by early exhaust valve closing to retain hot exhaust in the cylinder, thereby increasing the cylinder gas temperature. Test fuels were formulated with pure components to have the same RON, MON, and octane sensitivity as an indolene reference fuel, but with a wide range of fuel composition differences. Experiments have been carried out to determine if fuel composition plays a role in HCCImore » combustion properties, independent of octane numbers. Fuel economy, emissions, and combustion parameters have been measured at several fixed speed/load conditions over a range of exhaust valve closing angles. When the data are compared at constant combustion phasing, fuel effects on emissions and other combustion properties are small. However, when compared at constant exhaust valve closing angle, fuel composition effects are more pronounced, specifically regarding ignition. Operability range differences are also related to fuel composition. An all-paraffinic (normal, iso, and cycloparaffins) fuel exhibited distinctly earlier combustion phasing, increased rate of cylinder pressure rise, and increased rate of maximum heat release compared to the indolene reference fuel. Conversely, olefin-containing fuels exhibited retarded combustion phasing. The fuels with the most advanced ignition showed a wider operating range in terms of engine speed and load, irrespective of exhaust closing angle. These ignition differences reflect contributions from both fuel and EGR kinetics, the effects of which are discussed. The fuel composition variables are somewhat inter-correlated, which makes the experimental separation their effects imprecise with this small set of fuels, though clear trends are evident. The overall effects of fuel composition on engine performance and emissions are small. However, the results suggest that the effects on combustion phasing and engine operability range may need to be considered in the practical implementation of HCCI for fuels with large compositional variations.« less

Injector tip for an internal combustion engine

DOEpatents

Shyu, Tsu Pin; Ye, Wen

2003-05-20

This invention relates to a the tip structure of a fuel injector as used in a internal combustion engine. Internal combustion engines using Homogeneous Charge Compression Ignition (HCCI) technology require a tip structure that directs fuel spray in a downward direction. This requirement necessitates a tip design that is capable of withstanding mechanical stresses associated with the design.

Numerical Investigation Into Effect of Fuel Injection Timing on CAI/HCCI Combustion in a Four-Stroke GDI Engine

NASA Astrophysics Data System (ADS)

Cao, Li; Zhao, Hua; Jiang, Xi; Kalian, Navin

2006-02-01

The Controlled Auto-Ignition (CAI) combustion, also known as Homogeneous Charge Compression Ignition (HCCI), was achieved by trapping residuals with early exhaust valve closure in conjunction with direct injection. Multi-cycle 3D engine simulations have been carried out for parametric study on four different injection timings in order to better understand the effects of injection timings on in-cylinder mixing and CAI combustion. The full engine cycle simulation including complete gas exchange and combustion processes was carried out over several cycles in order to obtain the stable cycle for analysis. The combustion models used in the present study are the Shell auto-ignition model and the characteristic-time combustion model, which were modified to take the high level of EGR into consideration. A liquid sheet breakup spray model was used for the droplet breakup processes. The analyses show that the injection timing plays an important role in affecting the in-cylinder air/fuel mixing and mixture temperature, which in turn affects the CAI combustion and engine performance.

Global reaction mechanism for the auto-ignition of full boiling range gasoline and kerosene fuels

NASA Astrophysics Data System (ADS)

Vandersickel, A.; Wright, Y. M.; Boulouchos, K.

2013-12-01

Compact reaction schemes capable of predicting auto-ignition are a prerequisite for the development of strategies to control and optimise homogeneous charge compression ignition (HCCI) engines. In particular for full boiling range fuels exhibiting two stage ignition a tremendous demand exists in the engine development community. The present paper therefore meticulously assesses a previous 7-step reaction scheme developed to predict auto-ignition for four hydrocarbon blends and proposes an important extension of the model constant optimisation procedure, allowing for the model to capture not only ignition delays, but also the evolutions of representative intermediates and heat release rates for a variety of full boiling range fuels. Additionally, an extensive validation of the later evolutions by means of various detailed n-heptane reaction mechanisms from literature has been presented; both for perfectly homogeneous, as well as non-premixed/stratified HCCI conditions. Finally, the models potential to simulate the auto-ignition of various full boiling range fuels is demonstrated by means of experimental shock tube data for six strongly differing fuels, containing e.g. up to 46.7% cyclo-alkanes, 20% napthalenes or complex branched aromatics such as methyl- or ethyl-napthalene. The good predictive capability observed for each of the validation cases as well as the successful parameterisation for each of the six fuels, indicate that the model could, in principle, be applied to any hydrocarbon fuel, providing suitable adjustments to the model parameters are carried out. Combined with the optimisation strategy presented, the model therefore constitutes a major step towards the inclusion of real fuel kinetics into full scale HCCI engine simulations.

Extending operating range of a homogeneous charge compression ignition engine via cylinder deactivation

DOEpatents

Hergart, Carl-Anders [Peoria, IL; Hardy, William L [Peoria, IL; Duffy, Kevin P [Metamora, IL; Liechty, Michael P [Chillicothe, IL

2008-05-27

An HCCI engine has the ability to operate over a large load range by utilizing a lower cetane distillate diesel fuel to increase ignition delay. This permits more stable operation at high loads by avoidance of premature combustion before top dead center. During low load conditions, a portion of the engines cylinders are deactivated so that the remaining cylinders can operate at a pseudo higher load while the overall engine exhibits behavior typical of a relatively low load.

The influence of charge stratification on the spectral signature of partially premixed combustion in a light-duty optical engine

NASA Astrophysics Data System (ADS)

Najafabadi, M. Izadi; Egelmeers, Luc; Somers, Bart; Deen, Niels; Johansson, Bengt; Dam, Nico

2017-04-01

The origin of light emission during low-temperature combustion in a light-duty IC engine is investigated by high-speed spectroscopy in both HCCI and PPC regimes. Chemiluminescence and thermal radiation are expected to be the dominant sources of light emission during combustion. A method has been developed to distinguish chemiluminescence from thermal radiation, and different chemiluminescing species could be identified. Different combustion modes and global equivalence ratios are analyzed in this manner. The results indicate that the spectral signature (270-540 nm range) of the combustion is highly dependent on the stratification level. A significant broadband chemiluminescence signal is detected and superimposed on all spectra. This broadband chemiluminescence signal can reach up to 100 percent of the total signal in HCCI combustion, while it drops to around 80 percent for stratified combustion (PPC). We show that this broadband signal can be used as a measure for the heat release rate. The broadband chemiluminescence did also correlate with the equivalence ratio quite well in both HCCI and PPC regimes, suggesting that the total emission in the spectral region of 330-400 nm can serve as a proxy of equivalence ratio and the rate of heat release. Regarding C2* chemiluminescence, we see two different chemical mechanisms for formation of C2* in the PPC regime: first during the early stage of combustion by the breakup of bigger molecules and the second during the late stage of combustion when soot particles are forming.

Experimental Investigation of Piston Heat Transfer in a Light Duty Engine Under Conventional Diesel, Homogeneous Charge Compression Ignition, and Reactivity Controlled Compression Ignition Combustion Regimes

DTIC Science & Technology

2014-01-15

in a Light Duty Engine Under Conventional Diesel, Homogeneous Charge Compression Ignition , and Reactivity Controlled Compression Ignition ...Conventional Diesel (CDC), Homogeneous Charge Compression Ignition (HCCI), and Reactivity Controlled Compression Ignition (RCCI) combustion...LTC) regimes, including reactivity controlled compression ignition (RCCI), partially premixed combustion (PPC), and homogenous charge compression

The single-zone numerical model of homogeneous charge compression ignition engine performance

NASA Astrophysics Data System (ADS)

Fedyanov, E. A.; Itkis, E. M.; Kuzmin, V. N.; Shumskiy, S. N.

2017-02-01

The single-zone model of methane-air mixture combustion in the Homogeneous Charge Compression Ignition engine was developed. First modeling efforts resulted in the selection of the detailed kinetic reaction mechanism, most appropriate for the conditions of the HCCI process. Then, the model was completed so as to simulate the performance of the four-stroke engine and was coupled by physically reasonable adjusting functions. Validation of calculations against experimental data showed acceptable agreement.

A Framework for Quantifying Measurement Uncertainties and Uncertainty Propagation in HCCI/LTGC Engine Experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petitpas, Guillaume; McNenly, Matthew J.; Whitesides, Russell A.

In this study, a framework for estimating experimental measurement uncertainties for a Homogenous Charge Compression Ignition (HCCI)/Low-Temperature Gasoline Combustion (LTGC) engine testing facility is presented. Detailed uncertainty quantification is first carried out for the measurement of the in-cylinder pressure, whose variations during the cycle provide most of the information for performance evaluation. Standard uncertainties of other measured quantities, such as the engine geometry and speed, the air and fuel flow rate and the intake/exhaust dry molar fractions are also estimated. Propagating those uncertainties using a Monte Carlo simulation and Bayesian inference methods then allows for estimation of uncertainties of themore » mass-average temperature and composition at IVC and throughout the cycle; and also of the engine performances such as gross Integrated Mean Effective Pressure, Heat Release and Ringing Intensity. Throughout the analysis, nominal values for uncertainty inputs were taken from a well-characterized engine test facility. However, the analysis did not take into account the calibration practice of experiments run in that facility and the resulting uncertainty values are therefore not indicative of the expected accuracy of those experimental results. A future study will employ the methodology developed here to explore the effects of different calibration methods on the different uncertainty values in order to evaluate best practices for accurate engine measurements.« less

A Framework for Quantifying Measurement Uncertainties and Uncertainty Propagation in HCCI/LTGC Engine Experiments

DOE PAGES

Petitpas, Guillaume; McNenly, Matthew J.; Whitesides, Russell A.

2017-03-28

In this study, a framework for estimating experimental measurement uncertainties for a Homogenous Charge Compression Ignition (HCCI)/Low-Temperature Gasoline Combustion (LTGC) engine testing facility is presented. Detailed uncertainty quantification is first carried out for the measurement of the in-cylinder pressure, whose variations during the cycle provide most of the information for performance evaluation. Standard uncertainties of other measured quantities, such as the engine geometry and speed, the air and fuel flow rate and the intake/exhaust dry molar fractions are also estimated. Propagating those uncertainties using a Monte Carlo simulation and Bayesian inference methods then allows for estimation of uncertainties of themore » mass-average temperature and composition at IVC and throughout the cycle; and also of the engine performances such as gross Integrated Mean Effective Pressure, Heat Release and Ringing Intensity. Throughout the analysis, nominal values for uncertainty inputs were taken from a well-characterized engine test facility. However, the analysis did not take into account the calibration practice of experiments run in that facility and the resulting uncertainty values are therefore not indicative of the expected accuracy of those experimental results. A future study will employ the methodology developed here to explore the effects of different calibration methods on the different uncertainty values in order to evaluate best practices for accurate engine measurements.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petitpas, Guillaume; Whitesides, Russel

UQHCCI_2 propagates the uncertainties of mass-average quantities (temperature, heat capacity ratio) and the output performances (IMEP, heat release, CA50 and RI) of a HCCI engine test bench using the pressure trace, and intake and exhaust molar fraction and IVC temperature distributions, as inputs (those inputs may be computed using another code UQHCCI_2, or entered independently).

Engine Valve Actuation For Combustion Enhancement

DOEpatents

Reitz, Rolf Deneys; Rutland, Christopher J.; Jhavar, Rahul

2004-05-18

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Engine valve actuation for combustion enhancement

DOEpatents

Reitz, Rolf Deneys [Madison, WI; Rutland, Christopher J [Madison, WI; Jhavar, Rahul [Madison, WI

2008-03-04

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-strokes combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Comparing definitions of outpatient surgery: Implications for quality measurement.

PubMed

Mull, Hillary J; Rivard, Peter E; Legler, Aaron; Pizer, Steven D; Hawn, Mary T; Itani, Kamal M F; Rosen, Amy K

2017-08-01

Adverse event (AE) rates in outpatient surgery are inconsistently reported, partly because of the lack of a standard definition of outpatient surgery. We compared the types and rates of surgical procedures defined by two national healthcare agencies: Health Care Cost Institute (HCCI) and the Healthcare Cost and Utilization Project (HCUP) and considered implications for quality measurement. We used HCCI and HCUP definitions to identify FY2012-14 VA outpatient surgeries. There were six times as many HCCI surgeries as HCUP (6,575,830 versus 1,086,640). Ninety-nine percent of HCUP-defined surgeries were also identified by HCCI. More HCUP surgeries had higher average Medicare Relative Value Units then HCCI surgeries [5.3 (SD = 4.4) versus 1.6 (SD = 2.3) RVUs]. Rates and types of procedures vary widely between definitions. Quality measurement using HCCI versus HCUP may produce significantly lower AE rates because many of the surgeries included reflect low complexity and potentially low risk of AEs. Published by Elsevier Inc.

Laser-assisted homogeneous charge ignition in a constant volume combustion chamber

NASA Astrophysics Data System (ADS)

Srivastava, Dhananjay Kumar; Weinrotter, Martin; Kofler, Henrich; Agarwal, Avinash Kumar; Wintner, Ernst

2009-06-01

Homogeneous charge compression ignition (HCCI) is a very promising future combustion concept for internal combustion engines. There are several technical difficulties associated with this concept, and precisely controlling the start of auto-ignition is the most prominent of them. In this paper, a novel concept to control the start of auto-ignition is presented. The concept is based on the fact that most HCCI engines are operated with high exhaust gas recirculation (EGR) rates in order to slow-down the fast combustion processes. Recirculated exhaust gas contains combustion products including moisture, which has a relative peak of the absorption coefficient around 3 μm. These water molecules absorb the incident erbium laser radiations ( λ=2.79 μm) and get heated up to expedite ignition. In the present experimental work, auto-ignition conditions are locally attained in an experimental constant volume combustion chamber under simulated EGR conditions. Taking advantage of this feature, the time when the mixture is thought to "auto-ignite" could be adjusted/controlled by the laser pulse width optimisation, followed by its resonant absorption by water molecules present in recirculated exhaust gas.

An assessment of thermodynamic merits for current and potential future engine operating strategies

DOE PAGES

Wissink, Martin L.; Splitter, Derek A.; Dempsey, Adam B.; ...

2017-02-01

The present work compares the fundamental thermodynamic underpinnings (i.e., working fluid properties and heat release profile) of various combustion strategies with engine measurements. The approach employs a model that separately tracks the impacts on efficiency due to differences in rate of heat addition, volume change, mass addition, and molecular weight change for a given combination of working fluid, heat release profile, and engine geometry. Comparative analysis between measured and modeled efficiencies illustrates fundamental sources of efficiency reductions or opportunities inherent to various combustion regimes. Engine operating regimes chosen for analysis include stoichiometric spark-ignited combustion and lean compression-ignited combustion including HCCI,more » SA-HCCI, RCCI, GCI, and CDC. Within each combustion regime, effects such as engine load, combustion duration, combustion phasing, combustion chamber geometry, fuel properties, and charge dilution are explored. Model findings illustrate that even in the absence of losses such as heat transfer or incomplete combustion, the maximum possible thermal efficiency inherent to each operating strategy varies to a significant degree. Additionally, the experimentally measured losses are observed to be unique within a given operating strategy. The findings highlight the fact that in order to create a roadmap for future directions in ICE technologies, it is important to not only compare the absolute real-world efficiency of a given combustion strategy, but to also examine the measured efficiency in context of what is thermodynamically possible with the working fluid and boundary conditions prescribed by a strategy.« less

An assessment of thermodynamic merits for current and potential future engine operating strategies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wissink, Martin L.; Splitter, Derek A.; Dempsey, Adam B.

The present work compares the fundamental thermodynamic underpinnings (i.e., working fluid properties and heat release profile) of various combustion strategies with engine measurements. The approach employs a model that separately tracks the impacts on efficiency due to differences in rate of heat addition, volume change, mass addition, and molecular weight change for a given combination of working fluid, heat release profile, and engine geometry. Comparative analysis between measured and modeled efficiencies illustrates fundamental sources of efficiency reductions or opportunities inherent to various combustion regimes. Engine operating regimes chosen for analysis include stoichiometric spark-ignited combustion and lean compression-ignited combustion including HCCI,more » SA-HCCI, RCCI, GCI, and CDC. Within each combustion regime, effects such as engine load, combustion duration, combustion phasing, combustion chamber geometry, fuel properties, and charge dilution are explored. Model findings illustrate that even in the absence of losses such as heat transfer or incomplete combustion, the maximum possible thermal efficiency inherent to each operating strategy varies to a significant degree. Additionally, the experimentally measured losses are observed to be unique within a given operating strategy. The findings highlight the fact that in order to create a roadmap for future directions in ICE technologies, it is important to not only compare the absolute real-world efficiency of a given combustion strategy, but to also examine the measured efficiency in context of what is thermodynamically possible with the working fluid and boundary conditions prescribed by a strategy.« less

A new predictive multi-zone model for HCCI engine combustion

DOE PAGES

Bissoli, Mattia; Frassoldati, Alessio; Cuoci, Alberto; ...

2016-06-30

Here, this work introduces a new predictive multi-zone model for the description of combustion in Homogeneous Charge Compression Ignition (HCCI) engines. The model exploits the existing OpenSMOKE++ computational suite to handle detailed kinetic mechanisms, providing reliable predictions of the in-cylinder auto-ignition processes. All the elements with a significant impact on the combustion performances and emissions, like turbulence, heat and mass exchanges, crevices, residual burned gases, thermal and feed stratification are taken into account. Compared to other computational approaches, this model improves the description of mixture stratification phenomena by coupling a wall heat transfer model derived from CFD application with amore » proper turbulence model. Furthermore, the calibration of this multi-zone model requires only three parameters, which can be derived from a non-reactive CFD simulation: these adaptive variables depend only on the engine geometry and remain fixed across a wide range of operating conditions, allowing the prediction of auto-ignition, pressure traces and pollutants. This computational framework enables the use of detail kinetic mechanisms, as well as Rate of Production Analysis (RoPA) and Sensitivity Analysis (SA) to investigate the complex chemistry involved in the auto-ignition and the pollutants formation processes. In the final sections of the paper, these capabilities are demonstrated through the comparison with experimental data.« less

Control of harmful hydrocarbon species in the exhaust of modern advanced GDI engines

NASA Astrophysics Data System (ADS)

Hasan, A. O.; Abu-jrai, A.; Turner, D.; Tsolakis, A.; Xu, H. M.; Golunski, S. E.; Herreros, J. M.

2016-03-01

A qualitative and quantitative analysis of toxic but currently non-regulated hydrocarbon compounds ranging from C5-C11, before and after a zoned three-way catalytic converter (TWC) in a modern gasoline direct injection (GDI) engine has been studied using gas chromatography-mass spectrometry (GC-MS). The GDI engine has been operated under conventional and advanced combustion modes, which result in better fuel economy and reduced levels of NOx with respect to standard SI operation. However, these fuel-efficient conditions are more challenging for the operation of a conventional TWC, and could lead to higher level of emissions released to the environment. Lean combustion leads to the reduction in pumping losses, fuel consumption and in-cylinder emission formation rates. However, lean HCCI will lead to high levels of unburnt HCs while the presence of oxygen will lower the TWC efficiency for NOx control. The effect on the catalytic conversion of the hydrocarbon species of the addition of hydrogen upstream the catalyst has been also investigated. The highest hydrocarbon engine-out emissions were produced for HCCI engine operation at low engine load operation. The catalyst was able to remove most of the hydrocarbon species to low levels (below the permissible exposure limits) for standard and most of the advanced combustion modes, except for naphthalene (classified as possibly carcinogenic to humans by the International Agency for Research on Cancer) and methyl-naphthalene (which has the potential to cause lung damage). However, when hydrogen was added upstream of the catalyst, the catalyst conversion efficiency in reducing methyl-naphthalene and naphthalene was increased by approximately 21%. This results in simultaneous fuel economy and environmental benefits from the effective combination of advanced combustion and novel aftertreatment systems.

Advanced Boost System Developing for High EGR Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Harold

2012-09-30

To support industry efforts of clean and efficient internal combustion engine development for passenger and commercial applications • This program focuses on turbocharger improvement for medium and light duty diesel applications, from complete system optimization percepective to enable commercialization of advanced diesel combustion technologies, such as HCCI/LTC. • Improve combined turbocharger efficiency up to 10% or fuel economy by 3% on FTP cycle at Tier II Bin 5 emission level.

Optical investigation of the combustion behaviour inside the engine operating in HCCI mode and using alternative diesel fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mancaruso, E.; Vaglieco, B.M.

2010-04-15

In order to understand the effect of both the new homogeneous charge compression ignition (HCCI) combustion process and the use of biofuel, optical measurements were carried out into a transparent CR diesel engine. Rape seed methyl ester was used and tests with several injection pressures were performed. OH and HCO radical were detected and their evolutions were analyzed during the whole combustion. Moreover, soot concentration was measured by means the two colour pyrometry method. The reduction of particulate emission with biodiesel as compared to the diesel fuel was noted. Moreover, this effect resulted higher increasing the injection pressure. In themore » case of RME the oxidation of soot depends mainly from O{sub 2} content of fuel and OH is responsible of the NO formation in the chamber as it was observed for NO{sub x} exhaust emission. Moreover, it was investigated the evolution of HCO and CO into the cylinder. HCO was detected at the start of combustion. During the combustion, HCO oxidizes due to the increasing temperature and it produces CO. Both fuels have similar trend, the highest concentrations are detected for low injection pressure. This effect is more evident for the RME fuel. (author)« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehl, M; Kukkadapu, G; Kumar, K

The use of gasoline in homogeneous charge compression ignition engines (HCCI) and in duel fuel diesel - gasoline engines, has increased the need to understand its compression ignition processes under engine-like conditions. These processes need to be studied under well-controlled conditions in order to quantify low temperature heat release and to provide fundamental validation data for chemical kinetic models. With this in mind, an experimental campaign has been undertaken in a rapid compression machine (RCM) to measure the ignition of gasoline mixtures over a wide range of compression temperatures and for different compression pressures. By measuring the pressure history duringmore » ignition, information on the first stage ignition (when observed) and second stage ignition are captured along with information on the phasing of the heat release. Heat release processes during ignition are important because gasoline is known to exhibit low temperature heat release, intermediate temperature heat release and high temperature heat release. In an HCCI engine, the occurrence of low-temperature and intermediate-temperature heat release can be exploited to obtain higher load operation and has become a topic of much interest for engine researchers. Consequently, it is important to understand these processes under well-controlled conditions. A four-component gasoline surrogate model (including n-heptane, iso-octane, toluene, and 2-pentene) has been developed to simulate real gasolines. An appropriate surrogate mixture of the four components has been developed to simulate the specific gasoline used in the RCM experiments. This chemical kinetic surrogate model was then used to simulate the RCM experimental results for real gasoline. The experimental and modeling results covered ultra-lean to stoichiometric mixtures, compressed temperatures of 640-950 K, and compression pressures of 20 and 40 bar. The agreement between the experiments and model is encouraging in terms of first-stage (when observed) and second-stage ignition delay times and of heat release rate. The experimental and computational results are used to gain insight into low and intermediate temperature processes during gasoline ignition.« less

Assessing the Feasibility of a Multi-Program School-Based Intervention to Promote Physical Activity and Healthful Eating in Middle Schools Prior to Wide-Scale Implementation

ERIC Educational Resources Information Center

Greaney, Mary; Hardwick, Cary K.; Mezgebu, Solomon; Lindsay, Ana C.; Roover, Michelle L.; Peterson, Karen E.

2007-01-01

Background: University-community partnerships can support schools in implementing evidence-based responses to youth obesity trends. An inter-organizational partnership was established to implement and evaluate the Healthy Choices Collaborative Intervention (HCCI). HCCI combines an interdisciplinary curriculum, before/after school activities, and…

Method for reduction of the NOX emissions in marine auxiliary diesel engine using the fuel mixtures containing biodiesel using HCCI combustion.

PubMed

Puškár, Michal; Kopas, Melichar; Puškár, Dušan; Lumnitzer, Ján; Faltinová, Eva

2018-02-01

The marine auxiliary diesel engines installed in the large transoceanic ships are used in order to generate the electricity but at the same time these engines are able to produce a significant amount of the harmful exhaust gas emissions. Therefore the International Maritime Organisation (IMO) concluded an agreement, which has to control generating of gaseous emissions in maritime transport. From this reason started to be used some of the alternative fuels in this branch. There was performed a study, which investigated emissions of the auxiliary marine diesel engine during application of the experimental fuels. The different testing fuels were created using the ratios 0%, 50%, 80% and 100% between the biodiesel and the ULSDF (Ultra Low Sulphur Diesel Fuel). The experimental measurements were performed at the different engine loading levels and various engine speeds in order to investigate an influence of the mixed fuels on the engine operational characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Internal combustion engine report: Spark ignited ICE GenSet optimization and novel concept development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, J.; Blarigan, P. Van

1998-08-01

In this manuscript the authors report on two projects each of which the goal is to produce cost effective hydrogen utilization technologies. These projects are: (1) the development of an electrical generation system using a conventional four-stroke spark-ignited internal combustion engine generator combination (SI-GenSet) optimized for maximum efficiency and minimum emissions, and (2) the development of a novel internal combustion engine concept. The SI-GenSet will be optimized to run on either hydrogen or hydrogen-blends. The novel concept seeks to develop an engine that optimizes the Otto cycle in a free piston configuration while minimizing all emissions. To this end themore » authors are developing a rapid combustion homogeneous charge compression ignition (HCCI) engine using a linear alternator for both power take-off and engine control. Targeted applications include stationary electrical power generation, stationary shaft power generation, hybrid vehicles, and nearly any other application now being accomplished with internal combustion engines.« less

Transient flow characteristics of a high speed rotary valve

NASA Astrophysics Data System (ADS)

Browning, Patrick H.

Pressing economic and environmental concerns related to the performance of fossil fuel burning internal combustion engines have revitalized research in more efficient, cleaner burning combustion methods such as homogeneous charge compression ignition (HCCI). Although many variations of such engines now exist, several limiting factors have restrained the full potential of HCCI. A new method patented by West Virginia University (WVU) called Compression Ignition by Air Injection (CIBAI) may help broaden the range of effective HCCI operation. The CIBAI process is ideally facilitated by operating two synchronized piston-cylinders mounted head-to-head with one of the cylinders filled with a homogeneous mixture of air and fuel and the other cylinder filled with air. A specialized valve called the cylinder connecting valve (CCV) separates the two cylinders, opens just before reaching top dead center (TDC), and allows the injection air into the charge to achieve autoignition. The CCV remains open during the entire power stroke such that upon ignition the rapid pressure rise in the charge cylinder forces mass flow back through the CCV into the air-only cylinder. The limited mass transfer between the cylinders through the CCV limits the theoretical auto ignition timing capabilities and thermal efficiency of the CIBAI cycle. Research has been performed to: (1) Experimentally measure the transient behavior of a potential CCV design during valve opening between two chambers maintained at constant pressure and again at constant volume; (2) Develop a modified theoretical CCV mass flow model based upon the measured cold flow valve performance that is capable of predicting the operating conditions required for successful mixture autoignition; (3) Make recommendations for future CCV designs to maximize CIBAI combustion range. Results indicate that the modified-ball CCV design offers suitable transient flow qualities required for application to the CIBAI concept. Mass injection events were experimentally mapped as a function of valve speed, inter-cylinder pressure ratios and volume ratios and the results were compared to compressible flow theoretical models. Specifically, the transient behavior suggested a short-lived loss-mode initiation closely resembled by shock tube theory followed by a quasi-steady flow regime resembling choked flow behavior. An empirical model was then employed to determine the useful range of the CCV design as applied to a four-stroke CIBAI engine cycle modeled using a 1-D quasi-steady numerical method, with particular emphasis on the cyclic timing of the CCV opening. Finally, a brief discussion of a high-temperature version of the CCV design is presented.

Development of OTM Syngas Process and Testing of Syngas Derived Ultra-clean Fuels in Diesel Engines and Fuel Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

E.T. Robinson; John Sirman; Prasad Apte

2005-05-01

This final report summarizes work accomplished in the Program from January 1, 2001 through December 31, 2004. Most of the key technical objectives for this program were achieved. A breakthrough material system has lead to the development of an OTM (oxygen transport membrane) compact planar reactor design capable of producing either syngas or hydrogen. The planar reactor shows significant advantages in thermal efficiency and a step change reduction in costs compared to either autothermal reforming or steam methane reforming with CO{sub 2} recovery. Syngas derived ultra-clean transportation fuels were tested in the Nuvera fuel cell modular pressurized reactor and inmore » International Truck and Engine single cylinder test engines. The studies compared emission and engine performance of conventional base fuels to various formulations of ultra-clean gasoline or diesel fuels. A proprietary BP oxygenate showed significant advantage in both applications for reducing emissions with minimal impact on performance. In addition, a study to evaluate new fuel formulations for an HCCI engine was completed.« less

Overcoming barriers to a research-ready national commercial claims database.

PubMed

Newman, David; Herrera, Carolina-Nicole; Parente, Stephen T

2014-11-01

Billions of dollars have been spent on the goal of making healthcare data available to clinicians and researchers in the hopes of improving healthcare and lowering costs. However, the problems of data governance, distribution, and accessibility remain challenges for the healthcare system to overcome. In this study, we discuss some of the issues around holding, reporting, and distributing data, including the newest "big data" challenge: making the data accessible to researchers and policy makers. This article presents a case study in "big healthcare data" involving the Health Care Cost Institute (HCCI). HCCI is a nonprofit, nonpartisan, independent research institute that serves as a voluntary repository of national commercial healthcare claims data. Governance of large healthcare databases is complicated by the data-holding model and further complicated by issues related to distribution to research teams. For multi-payer healthcare claims databases, the 2 most common models of data holding (mandatory and voluntary) have different data security requirements. Furthermore, data transport and accessibility may require technological investment. HCCI's efforts offer insights from which other data managers and healthcare leaders may benefit when contemplating a data collaborative.

DNS Study of the Ignition of n-Heptane Fuel Spray under HCCI Conditions

NASA Astrophysics Data System (ADS)

Wang, Yunliang; Rutland, Christopher J.

2004-11-01

Direct numerical simulations are carried out to investigate the mixing and auto-ignition processes of n-heptane fuel spray in a turbulent field using a skeletal chemistry mechanism with 44 species and 112 reactions. For the solution of the carrier gas fluid, we use the Eulerian method, while for the fuel spray, the Lagrangian method is used. We use an eighth-order finite difference scheme to calculate spacial derivatives and a fourth-order Runge-Kutta scheme for the time integration. The initial gas temperature is 926 K and the initial gas pressure is 30 atmospheres. The initial global equivalence ratio based on the fuel concentration is around 0.4. The initial droplet diameter is 60 macrons and the droplet temperature is 300 K. Evolutions of averaged temperature, species mass fraction, heat release and reaction rate are presented. Contours of temperature and species mass fractions are presented. The objective is to understand the mechanism of ignition under Homogeneous Charged Compression Ignition (HCCI) conditions, aiming at providing some useful information of HCCI combustion, which is one of the critical issues to be resolved.

Effect of Hydrogen Addition on Methane HCCI Engine Ignition Timing and Emissions Using a Multi-zone Model

NASA Astrophysics Data System (ADS)

Wang, Zi-han; Wang, Chun-mei; Tang, Hua-xin; Zuo, Cheng-ji; Xu, Hong-ming

2009-06-01

Ignition timing control is of great importance in homogeneous charge compression ignition engines. The effect of hydrogen addition on methane combustion was investigated using a CHEMKIN multi-zone model. Results show that hydrogen addition advances ignition timing and enhances peak pressure and temperature. A brief analysis of chemical kinetics of methane blending hydrogen is also performed in order to investigate the scope of its application, and the analysis suggests that OH radical plays an important role in the oxidation. Hydrogen addition increases NOx while decreasing HC and CO emissions. Exhaust gas recirculation (EGR) also advances ignition timing; however, its effects on emissions are generally the opposite. By adjusting the hydrogen addition and EGR rate, the ignition timing can be regulated with a low emission level. Investigation into zones suggests that NOx is mostly formed in core zones while HC and CO mostly originate in the crevice and the quench layer.

Energy distribution analysis in boosted HCCI-like / LTGC engines – Understanding the trade-offs to maximize the thermal efficiency

DOE PAGES

Dernotte, Jeremie; Dec, John E.; Ji, Chunsheng

2015-04-14

A detailed understanding of the various factors affecting the trends in gross-indicated thermal efficiency with changes in key operating parameters has been carried out, applied to a one-liter displacement single-cylinder boosted Low-Temperature Gasoline Combustion (LTGC) engine. This work systematically investigates how the supplied fuel energy splits into the following four energy pathways: gross-indicated thermal efficiency, combustion inefficiency, heat transfer and exhaust losses, and how this split changes with operating conditions. Additional analysis is performed to determine the influence of variations in the ratio of specific heat capacities (γ) and the effective expansion ratio, related to the combustion-phasing retard (CA50), onmore » the energy split. Heat transfer and exhaust losses are computed using multiple standard cycle analysis techniques. Furthermore, the various methods are evaluated in order to validate the trends.« less

Mapping surrogate gasoline compositions into RON/MON space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan, Neal; Kraft, Markus; Smallbone, Andrew

2010-06-15

In this paper, new experimentally determined octane numbers (RON and MON) of blends of a tri-component surrogate consisting of toluene, n-heptane, i-octane (called toluene reference fuel TRF) arranged in an augmented simplex design are used to derive a simple response surface model for the octane number of any arbitrary TRF mixture. The model is second-order in its complexity and is shown to be more accurate to the standard ''linear-by-volume'' (LbV) model which is often used when no other information is available. Such observations are due to the existence of both synergistic and antagonistic blending of the octane numbers between themore » three components. In particular, antagonistic blending of toluene and iso-octane leads to a maximum in sensitivity that lies on the toluene/iso-octane line. The model equations are inverted so as to map from RON/MON space back into composition space. Enabling one to use two simple formulae to determine, for a given fuel with known RON and MON, the volume fractions of toluene, n-heptane and iso-octane to be blended in order to emulate that fuel. HCCI engine simulations using gasoline with a RON of 98.5 and a MON of 88 were simulated using a TRF fuel, blended according to the derived equations to match the RON and MON. The simulations matched the experimentally obtained pressure profiles well, especially when compared to simulations using only PRF fuels which matched the RON or MON. This suggested that the mapping is accurate and that to emulate a refinery gasoline, it is necessary to match not only the RON but also the MON of the fuel. (author)« less

Detailed kinetic modeling study of n-pentanol oxidation

DOE PAGES

Heufer, K. Alexander; Sarathy, S. Mani; Curran, Henry J.; ...

2012-09-28

To help overcome the world’s dependence upon fossil fuels, suitable biofuels are promising alternatives that can be used in the transportation sector. Recent research on internal combustion engines shows that short alcoholic fuels (e.g., ethanol or n-butanol) have reduced pollutant emissions and increased knock resistance compared to fossil fuels. Although higher molecular weight alcohols (e.g., n-pentanol and n-hexanol) exhibit higher reactivity that lowers their knock resistance, they are suitable for diesel engines or advanced engine concepts, such as homogeneous charge compression ignition (HCCI), where higher reactivity at lower temperatures is necessary for engine operation. The present study presents a detailedmore » kinetic model for n-pentanol based on modeling rules previously presented for n-butanol. This approach was initially validated using quantum chemistry calculations to verify the most stable n-pentanol conformation and to obtain C–H and C–C bond dissociation energies. In addition, the proposed model has been validated against ignition delay time data, speciation data from a jet-stirred reactor, and laminar flame velocity measurements. Overall, the model shows good agreement with the experiments and permits a detailed discussion of the differences between alcohols and alkanes.« less

Spectroscopic and chemical-kinetic analysis of the phases of HCCI autoignition and combustion for single- and two-stage ignition fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Wontae; Dec, John; Sjoeberg, Magnus

The temporal phases of autoignition and combustion in an HCCI engine have been investigated in both an all-metal engine and a matching optical engine. Gasoline, a primary reference fuel mixture (PRF80), and several representative real-fuel constituents were examined. Only PRF80, which is a two-stage ignition fuel, exhibited a ''cool-flame'' low-temperature heat-release (LTHR) phase. For all fuels, slow exothermic reactions occurring at intermediate temperatures raised the charge temperature to the hot-ignition point. In addition to the amount of LTHR, differences in this intermediate-temperature heat-release (ITHR) phase affect the fuel ignition quality. Chemiluminescence images of iso-octane show a weak and uniform lightmore » emission during this phase. This is followed by the main high-temperature heat-release (HTHR) phase. Finally, a ''burnout'' phase was observed, with very weak uniform emission and near-zero heat-release rate (HRR). To better understand these combustion phases, chemiluminescence spectroscopy and chemical-kinetic analysis were applied for the single-stage ignition fuel, iso-octane, and the two-stage fuel, PRF80. For both fuels, the spectrum obtained during the ITHR phase was dominated by formaldehyde chemiluminescence. This was similar to the LTHR spectrum of PRF80, but the emission intensity and the temperature were much higher, indicating differences between the ITHR and LTHR phases. Chemical-kinetic modeling clarified the differences and similarities between the LTHR and ITHR phases and the cause of the enhanced ITHR with PRF80. The HTHR spectra for both fuels were dominated by a broad CO continuum with some contribution from bands of HCO, CH, and OH. The modeling showed that the CO+ O{yields}CO{sub 2}+h{nu} reaction responsible for the CO continuum emission tracks the HTHR well, explaining the strong correlation observed experimentally between the total chemiluminescence and HRR during the HTHR phase. It also showed that the CO continuum does not contribute to the ITHR and LTHR chemiluminescence. Bands of H{sub 2}O and O{sub 2} in the red and IR regions were also detected during the HTHR, which the data indicated were most likely due to thermal excitation. The very weak light emission in the ''burnout'' phase also appeared to be thermal emission from H{sub 2}O and O{sub 2}. (author)« less

Modeling and Simulation of a Free-Piston Engine with Electrical Generator Using HCCI Combustion

NASA Astrophysics Data System (ADS)

Alrbai, Mohammad

Free-piston engines have the potential to challenge the conventional crankshaft engines by their design simplicity and higher operational efficiency. Many studies have been performed to overcome the limitations of the free-piston devices especially the stability and control issues. The investigations within the presented dissertation aim to satisfy many objectives by employing the approach of chemical kinetics to present the combustion process in the free-piston engine. This approach in addition to its advanced accuracy over the empirical methods, it has many other features like the ability to analyze the engine emissions. The effect of the heat release rate (HRR) on the engine performance is considered as the main objective. Understanding the relation between the HRR and the piston dynamics helps in enhancing the system efficiency and identifying the parameters that affect the overall performance. The dissertation covers some other objectives that belongs to the combustion phasing. Exhaust gas recirculation (EGR), equivalence ratio and the intake temperature represent the main combustion parameters, which have been discussed in this dissertation. To obtain the stability in system performance, the model requires a proper controller to simulate the operation and manage the different system parameters; for this purpose, different controlling techniques have been employed. In addition, the dissertation considers some other topics like engine emissions, fuels and fuels mechanisms. The model of the study describes the processes within a single cylinder, two stroke engine, which includes springs to support higher frequencies, reduce cyclic variations and sustain the engine compression ratio. An electrical generator presents the engine load; the generator supports different load profiles and play the key role in controlling the system. The 1st law of thermodynamics and Newton's 2nd law are applied to couple the piston dynamics with the engine thermodynamics. The model governing equations represent a single zone perfectly stirred reactor (PSR) which contain a perfect mixing ideal gas mixture. The chemical kinetics approach is applied using Cantera/ MATLABRTM toolbox, which presents the combustion process. In this research, a homogenous charge compression ignition (HCCI) at different operational conditions is used. HCCI engines have high efficiencies and low emissions and can work within a wide range of fuels. The results have been presented in a multi-cycle simulation and a parametric study forms. In the case of the multi-cycle simulation, a 100 cycles of the engine operation have been simulated. The overall work that is delivered to the electrical generator presents 47% of the total fuel energy. The model indicates an average frequency of 125 Hz along the operational cycles. In order to eliminate the cyclic variations and ensure a continuous operation, a proportional derivative (PD) controller has been employed. The controller adjusts the generator load in order to minimize the difference between the bottom dead center (BDC) locations along the operation cycles. The PD controller shows weakness in achieving the full steady state operation, for this purpose; a proportional integral (PI) controller has been implemented. The PI controller seeks to achieve a specific compression ratio. The results show that; the PI controller indicates unique behavior after 15 cycles of operation where the model ended to fluctuate between two compression ratios only. The complex relation between the thermodynamics and the dynamics of the engine is the greatest challenge in examining the effectiveness of the PI controller. In the parametric investigations, EGR examinations show that NOx emission is reduced to less than the half, as 30 % of EGR is used; this occurs due to the EGR thermal and dilution effects, which cause significant drop in the peak bulk temperature and CO emissions as well. Under the applied conditions, EGR has the ability to raise the work output ratio by increasing the engine compression ratio. The examination of the EGR temperature on the engine performance indicates that cooled EGR charges have the advantage over the hot EGR mixtures on enhancing the work output ratio. At the same time, EGR temperature affects the NOx formation by speeding its instantaneous reactions rate. The dissertation includes a study of the effect of the intake temperature and the equivalence ratio (φ) as well. The increasing in the intake temperature reduce the time needed for ignition, but leads to a reduction in the work output ratio at the same time. Such results can help in studying high knock resistance fuels where ignition delay is a matter. In the case of the equivalence ratio, lean mixtures show efficiencies that exceed 50% compared to those at the stoichiometric conditions. In the case of the ultra-lean (φ<0.5) combustion, the results show that the NOx emission is with the minimal levels as well as the CO and the unburned hydrocarbons (UHC) emissions. Sensitivity analysis to the chemical kinetic mechanism for the fuel combustion has been presented also in the dissertation. Many mechanisms for different fuels have been investigated, for example; a modified mechanism for Methane that includes 36 species and 222 reactions has been compared with the full GRI 3.0 mechanism (53 species and 325 reactions). The results of this comparison indicate that the modified mechanism has the potential to replace the full one in some cases like in demonstrating the engine operation, but not in the engine emissions analysis.

Sound quality assessment of Diesel combustion noise using in-cylinder pressure components

NASA Astrophysics Data System (ADS)

Payri, F.; Broatch, A.; Margot, X.; Monelletta, L.

2009-01-01

The combustion process in direct injection (DI) Diesel engines is an important source of noise, and it is thus the main reason why end-users could be reluctant to drive vehicles powered with this type of engine. This means that the great potential of Diesel engines for environment preservation—due to their lower consumption and the subsequent reduction of CO2 emissions—may be lost. Moreover, the advanced combustion concepts—e.g. the HCCI (homogeneous charge compression ignition)—developed to comply with forthcoming emissions legislation, while maintaining the efficiency of current engines, are expected to be noisier because they are characterized by a higher amount of premixed combustion. For this reason many efforts have been dedicated by car manufacturers in recent years to reduce the overall level and improve the sound quality of engine noise. Evaluation procedures are required, both for noise levels and sound quality, that may be integrated in the global engine development process in a timely and cost-effective manner. In previous published work, the authors proposed a novel method for the assessment of engine noise level. A similar procedure is applied in this paper to demonstrate the suitability of combustion indicators for the evaluation of engine noise quality. These indicators, which are representative of the peak velocity of fuel burning and the resonance in the combustion chamber, are well correlated with the combustion noise mark obtained from jury testing. Quite good accuracy in the prediction of the engine noise quality has been obtained with the definition of a two-component regression, which also permits the identification of the combustion process features related to the resulting noise quality, so that corrective actions may be proposed.

Impact of Formaldehyde Addition on Auto-Ignition in Internal-Combustion Engines

NASA Astrophysics Data System (ADS)

Kuwahara, Kazunari; Ando, Hiromitsu; Furutani, Masahiro; Ohta, Yasuhiko

By employing a direct-injection diesel engine equipped with a common-rail type of injection system, by adding formaldehyde (CH2O) to the intake air, and by changing the fuel-injection timing, the compression ratio and the intake-air temperature, a mechanism for CH2O as a fuel additive to affect auto-ignition was discussed. Unlike an HCCI type of engine, the diesel engine can expose an air-fuel mixture only to a limited range of the in-cylinder temperature before the ignition, and can separate low- and high-temperature parts of the mechanism. When low-temperature oxidation starts at a temperature above 900K, there are cases that the CH2O advances the ignition timing. Below 900K, to the contrary, it always retards the timing. It is because, above 900K, a part of the CH2O changes into CO together with H2O2 as an ignition promoter. Below 900K, on the other hand, the CH2O itself acts as an OH radical scavenger against cool-flame reaction, from the beginning of low-temperature oxidation. Then, the engine was modified for its extraordinary function as a gasoline-knocking generator, in order that an effect of CH2O on knocking could be discussed. The CH2O retards the onset of auto-ignition of an end gas. Judging from a large degree of the retardation, the ignition is probably triggered below 900K.

Emission Characteristics of a Diesel Engine Operating with In-Cylinder Gasoline and Diesel Fuel Blending

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prikhodko, Vitaly Y; Curran, Scott; Barone, Teresa L

2010-01-01

Advanced combustion regimes such as homogeneous charge compression ignition (HCCI) and premixed charge compression ignition (PCCI) offer benefits of reduced nitrogen oxides (NOx) and particulate matter (PM) emissions. However, these combustion strategies often generate higher carbon monoxide (CO) and hydrocarbon (HC) emissions. In addition, aldehydes and ketone emissions can increase in these modes. In this study, the engine-out emissions of a compression-ignition engine operating in a fuel reactivity- controlled PCCI combustion mode using in-cylinder blending of gasoline and diesel fuel have been characterized. The work was performed on a 1.9-liter, 4-cylinder diesel engine outfitted with a port fuel injection systemmore » to deliver gasoline to the engine. The engine was operated at 2300 rpm and 4.2 bar brake mean effective pressure (BMEP) with the ratio of gasoline to diesel fuel that gave the highest engine efficiency and lowest emissions. Engine-out emissions for aldehydes, ketones and PM were compared with emissions from conventional diesel combustion. Sampling and analysis was carried out following micro-tunnel dilution of the exhaust. Particle geometric mean diameter, number-size distribution, and total number concentration were measured by a scanning mobility particle sizer (SMPS). For the particle mass measurements, samples were collected on Teflon-coated quartz-fiber filters and analyzed gravimetrically. Gaseous aldehydes and ketones were sampled using dinitrophenylhydrazine-coated solid phase extraction cartridges and the extracts were analyzed by liquid chromatography/mass spectrometry (LC/MS). In addition, emissions after a diesel oxidation catalyst (DOC) were also measured to investigate the destruction of CO, HC and formaldehydes by the catalyst.« less

Acceleration of the chemistry solver for modeling DI engine combustion using dynamic adaptive chemistry (DAC) schemes

NASA Astrophysics Data System (ADS)

Shi, Yu; Liang, Long; Ge, Hai-Wen; Reitz, Rolf D.

2010-03-01

Acceleration of the chemistry solver for engine combustion is of much interest due to the fact that in practical engine simulations extensive computational time is spent solving the fuel oxidation and emission formation chemistry. A dynamic adaptive chemistry (DAC) scheme based on a directed relation graph error propagation (DRGEP) method has been applied to study homogeneous charge compression ignition (HCCI) engine combustion with detailed chemistry (over 500 species) previously using an R-value-based breadth-first search (RBFS) algorithm, which significantly reduced computational times (by as much as 30-fold). The present paper extends the use of this on-the-fly kinetic mechanism reduction scheme to model combustion in direct-injection (DI) engines. It was found that the DAC scheme becomes less efficient when applied to DI engine simulations using a kinetic mechanism of relatively small size and the accuracy of the original DAC scheme decreases for conventional non-premixed combustion engine. The present study also focuses on determination of search-initiating species, involvement of the NOx chemistry, selection of a proper error tolerance, as well as treatment of the interaction of chemical heat release and the fuel spray. Both the DAC schemes were integrated into the ERC KIVA-3v2 code, and simulations were conducted to compare the two schemes. In general, the present DAC scheme has better efficiency and similar accuracy compared to the previous DAC scheme. The efficiency depends on the size of the chemical kinetics mechanism used and the engine operating conditions. For cases using a small n-heptane kinetic mechanism of 34 species, 30% of the computational time is saved, and 50% for a larger n-heptane kinetic mechanism of 61 species. The paper also demonstrates that by combining the present DAC scheme with an adaptive multi-grid chemistry (AMC) solver, it is feasible to simulate a direct-injection engine using a detailed n-heptane mechanism with 543 species with practical computer time.

Numerical simulation and validation of SI-CAI hybrid combustion in a CAI/HCCI gasoline engine

NASA Astrophysics Data System (ADS)

Wang, Xinyan; Xie, Hui; Xie, Liyan; Zhang, Lianfang; Li, Le; Chen, Tao; Zhao, Hua

2013-02-01

SI-CAI hybrid combustion, also known as spark-assisted compression ignition (SACI), is a promising concept to extend the operating range of CAI (Controlled Auto-Ignition) and achieve the smooth transition between spark ignition (SI) and CAI in the gasoline engine. In this study, a SI-CAI hybrid combustion model (HCM) has been constructed on the basis of the 3-Zones Extended Coherent Flame Model (ECFM3Z). An ignition model is included to initiate the ECFM3Z calculation and induce the flame propagation. In order to precisely depict the subsequent auto-ignition process of the unburned fuel and air mixture independently after the initiation of flame propagation, the tabulated chemistry concept is adopted to describe the auto-ignition chemistry. The methodology for extracting tabulated parameters from the chemical kinetics calculations is developed so that both cool flame reactions and main auto-ignition combustion can be well captured under a wider range of thermodynamic conditions. The SI-CAI hybrid combustion model (HCM) is then applied in the three-dimensional computational fluid dynamics (3-D CFD) engine simulation. The simulation results are compared with the experimental data obtained from a single cylinder VVA engine. The detailed analysis of the simulations demonstrates that the SI-CAI hybrid combustion process is characterised with the early flame propagation and subsequent multi-site auto-ignition around the main flame front, which is consistent with the optical results reported by other researchers. Besides, the systematic study of the in-cylinder condition reveals the influence mechanism of the early flame propagation on the subsequent auto-ignition.

Direct Numerical Simulations of Autoignition in Stratified Dimethyl-ether (DME)/Air Turbulent Mixtures

DOE PAGES

Bansal, Gaurav; Mascarenhas, Ajith; Chen, Jacqueline H.

2014-10-01

In our paper, two- and three-dimensional direct numerical simulations (DNS) of autoignition phenomena in stratified dimethyl-ether (DME)/air turbulent mixtures are performed. A reduced DME oxidation mechanism, which was obtained using rigorous mathematical reduction and stiffness removal procedure from a detailed DME mechanism with 55 species, is used in the present DNS. The reduced DME mechanism consists of 30 chemical species. This study investigates the fundamental aspects of turbulence-mixing-autoignition interaction occurring in homogeneous charge compression ignition (HCCI) engine environments. A homogeneous isotropic turbulence spectrum is used to initialize the velocity field in the domain. Moreover, the computational configuration corresponds to amore » constant volume combustion vessel with inert mass source terms added to the governing equations to mimic the pressure rise due to piston motion, as present in practical engines. DME autoignition is found to be a complex three-staged process; each stage corresponds to a distinct chemical kinetic pathway. The distinct role of turbulence and reaction in generating scalar gradients and hence promoting molecular transport processes are investigated. Then, by applying numerical diagnostic techniques, the different heat release modes present in the igniting mixture are identified. In particular, the contribution of homogeneous autoignition, spontaneous ignition front propagation, and premixed deflagration towards the total heat release are quantified.« less

Onboard Plasmatron Hydrogen Production for Improved Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniel R. Cohn; Leslie Bromberg; Kamal Hadidi

2005-12-31

A plasmatron fuel reformer has been developed for onboard hydrogen generation for vehicular applications. These applications include hydrogen addition to spark-ignition internal combustion engines, NOx trap and diesel particulate filter (DPF) regeneration, and emissions reduction from spark ignition internal combustion engines First, a thermal plasmatron fuel reformer was developed. This plasmatron used an electric arc with relatively high power to reform fuels such as gasoline, diesel and biofuels at an oxygen to carbon ratio close to 1. The draw back of this device was that it has a high electric consumption and limited electrode lifetime due to the high temperaturemore » electric arc. A second generation plasmatron fuel reformer was developed. It used a low-current high-voltage electric discharge with a completely new electrode continuation. This design uses two cylindrical electrodes with a rotating discharge that produced low temperature volumetric cold plasma., The lifetime of the electrodes was no longer an issue and the device was tested on several fuels such as gasoline, diesel, and biofuels at different flow rates and different oxygen to carbon ratios. Hydrogen concentration and yields were measured for both the thermal and non-thermal plasmatron reformers for homogeneous (non-catalytic) and catalytic reforming of several fuels. The technology was licensed to an industrial auto part supplier (ArvinMeritor) and is being implemented for some of the applications listed above. The Plasmatron reformer has been successfully tested on a bus for NOx trap regeneration. The successful development of the plasmatron reformer and its implementation in commercial applications including transportation will bring several benefits to the nation. These benefits include the reduction of NOx emissions, improving engine efficiency and reducing the nation's oil consumption. The objective of this program has been to develop attractive applications of plasmatron fuel reformer technology for onboard applications in internal combustion engine vehicles using diesel, gasoline and biofuels. This included the reduction of NOx and particulate matter emissions from diesel engines using plasmatron reformer generated hydrogen-rich gas, conversion of ethanol and bio-oils into hydrogen rich gas, and the development of new concepts for the use of plasmatron fuel reformers for enablement of HCCI engines.« less

A simple dynamic engine model for use in a real-time aircraft simulation with thrust vectoring

NASA Technical Reports Server (NTRS)

Johnson, Steven A.

1990-01-01

A simple dynamic engine model was developed at the NASA Ames Research Center, Dryden Flight Research Facility, for use in thrust vectoring control law development and real-time aircraft simulation. The simple dynamic engine model of the F404-GE-400 engine (General Electric, Lynn, Massachusetts) operates within the aircraft simulator. It was developed using tabular data generated from a complete nonlinear dynamic engine model supplied by the manufacturer. Engine dynamics were simulated using a throttle rate limiter and low-pass filter. Included is a description of a method to account for axial thrust loss resulting from thrust vectoring. In addition, the development of the simple dynamic engine model and its incorporation into the F-18 high alpha research vehicle (HARV) thrust vectoring simulation. The simple dynamic engine model was evaluated at Mach 0.2, 35,000 ft altitude and at Mach 0.7, 35,000 ft altitude. The simple dynamic engine model is within 3 percent of the steady state response, and within 25 percent of the transient response of the complete nonlinear dynamic engine model.

Creating Simple Admin Tools Using Info*Engine and Java

NASA Technical Reports Server (NTRS)

Jones, Corey; Kapatos, Dennis; Skradski, Cory; Felkins, J. D.

2012-01-01

PTC has provided a simple way to dynamically interact with Windchill using Info*Engine. This presentation will describe how to create a simple Info*Engine Tasks capable of saving Windchill 10.0 administration of tedious work.

Creating Simple Windchill Admin Tools Using Info*Engine

NASA Technical Reports Server (NTRS)

Jones, Corey; Kapatos, Dennis; Skradski, Cory

2012-01-01

Being a Windchill administrator often requires performing simple yet repetitive tasks on large sets of objects. These can include renaming, deleting, checking in, undoing checkout, and much more. This is especially true during a migration. Fortunately, PTC has provided a simple way to dynamically interact with Windchill using Info*Engine. This presentation will describe how to create simple Info*Engine tasks capable of saving Windchill 10.0 administrators hours of tedious work. It will also show how these tasks can be combined and displayed on a simple JSP page that acts as a "Windchill Administrator Dashboard/Toolbox". The attendee will learn some valuable tasks Info*Engine capable of performing. The attendee will gain a basic understanding of how to perform and implement Info*Engine tasks. The attendee will learn what's involved in creating a JSP page that displays Info*Engine tasks

Low-Temperature Combustion of High Octane Fuels in a Gasoline Compression Ignition Engine

DOE PAGES

Cung, Khanh Duc; Ciatti, Stephen Anthony; Tanov, Slavey; ...

2017-12-21

Gasoline Compression Ignition (GCI) has been shown as one of the advanced combustion concepts that could potentially provide a pathway to achieve cleaner and more efficient combustion engines. Fuel and air in GCI are not fully premixed as compared to homogeneous charge compression ignition (HCCI) which is a completely kinetic-controlled combustion system. Therefore, the combustion phasing can be controlled by the time of injection, usually post injection in a multiple-injection scheme, to mitigate combustion noise. Gasoline fuels ignite more difficult than Diesel. The autoignition quality of gasoline can be indicated by research octane number (RON). Fuels with high octane tendmore » to have more resistance to auto-ignition, hence more time for fuel-air mixing. In this study, three fuels, namely, Aromatic, Alkylate, and E30, with similar RON value of 98 but different hydrocarbon compositions were tested in a multi-cylinder engine under GCI combustion mode. Considerations of EGR, start of injection (SOI), and boost were investigated to study the sensitivity of dilution, local stratification, and reactivity of the charge, respectively, for each fuel. Combustion phasing was kept constant during the experiments to the changes in ignition and combustion process before and after 50% of the fuel mass is burned. Emission characteristics at different levels of EGR and lambda were revealed for all fuels with E30 having the lowest filter smoke number (FSN) and was also most sensitive to the change in dilution. Reasonably low combustion noise (< 90 dB) and stable combustion (COVIMEP < 3%) were maintained during the experiments. The second part of this paper contains visualization of the combustion process obtained from endoscope imaging for each fuel at selected conditions. Soot radiation signal from GCI combustion were strong during late injection, and also more intense at low EGR conditions. Furthermore, soot/temperature profiles indicated only the high-temperature combustion period, while cylinder pressure-based heat release rate (HRR) showed a two-stage combustion phenomenon.« less

Effect of E85 on RCCI Performance and Emissions on a Multi-Cylinder Light-Duty Diesel Engine - SAE World Congress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curran, Scott; Hanson, Reed M; Wagner, Robert M

2012-01-01

This paper investigates the effect of E85 on load expansion and FTP modal point emissions indices under reactivity controlled compression ignition (RCCI) operation on a light-duty multi-cylinder diesel engine. A General Motors (GM) 1.9L four-cylinder diesel engine with the stock compression ratio of 17.5:1, common rail diesel injection system, high-pressure exhaust gas recirculation (EGR) system and variable geometry turbocharger was modified to allow for port fuel injection with gasoline or E85. Controlling the fuel reactivity in-cylinder by the adjustment of the ratio of premixed low-reactivity fuel (gasoline or E85) to direct injected high reactivity fuel (diesel fuel) has been shownmore » to extend the operating range of high-efficiency clean combustion (HECC) compared to the use of a single fuel alone as in homogeneous charge compression ignition (HCCI) or premixed charge compression ignition (PCCI). The effect of E85 on the Ad-hoc federal test procedure (FTP) modal points is explored along with the effect of load expansion through the light-duty diesel speed operating range. The Ad-hoc FTP modal points of 1500 rpm, 1.0bar brake mean effective pressure (BMEP); 1500rpm, 2.6bar BMEP; 2000rpm, 2.0bar BMEP; 2300rpm, 4.2bar BMEP; and 2600rpm, 8.8bar BMEP were explored. Previous results with 96 RON unleaded test gasoline (UTG-96) and ultra-low sulfur diesel (ULSD) showed that with stock hardware, the 2600rpm, 8.8bar BMEP modal point was not obtainable due to excessive cylinder pressure rise rate and unstable combustion both with and without the use of EGR. Brake thermal efficiency and emissions performance of RCCI operation with E85 and ULSD is explored and compared against conventional diesel combustion (CDC) and RCCI operation with UTG 96 and ULSD.« less

Low-Temperature Combustion of High Octane Fuels in a Gasoline Compression Ignition Engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cung, Khanh Duc; Ciatti, Stephen Anthony; Tanov, Slavey

Gasoline Compression Ignition (GCI) has been shown as one of the advanced combustion concepts that could potentially provide a pathway to achieve cleaner and more efficient combustion engines. Fuel and air in GCI are not fully premixed as compared to homogeneous charge compression ignition (HCCI) which is a completely kinetic-controlled combustion system. Therefore, the combustion phasing can be controlled by the time of injection, usually post injection in a multiple-injection scheme, to mitigate combustion noise. Gasoline fuels ignite more difficult than Diesel. The autoignition quality of gasoline can be indicated by research octane number (RON). Fuels with high octane tendmore » to have more resistance to auto-ignition, hence more time for fuel-air mixing. In this study, three fuels, namely, Aromatic, Alkylate, and E30, with similar RON value of 98 but different hydrocarbon compositions were tested in a multi-cylinder engine under GCI combustion mode. Considerations of EGR, start of injection (SOI), and boost were investigated to study the sensitivity of dilution, local stratification, and reactivity of the charge, respectively, for each fuel. Combustion phasing was kept constant during the experiments to the changes in ignition and combustion process before and after 50% of the fuel mass is burned. Emission characteristics at different levels of EGR and lambda were revealed for all fuels with E30 having the lowest filter smoke number (FSN) and was also most sensitive to the change in dilution. Reasonably low combustion noise (< 90 dB) and stable combustion (COVIMEP < 3%) were maintained during the experiments. The second part of this paper contains visualization of the combustion process obtained from endoscope imaging for each fuel at selected conditions. Soot radiation signal from GCI combustion were strong during late injection, and also more intense at low EGR conditions. Furthermore, soot/temperature profiles indicated only the high-temperature combustion period, while cylinder pressure-based heat release rate (HRR) showed a two-stage combustion phenomenon.« less

Experimental investigation of gasoline compression ignition combustion in a light-duty diesel engine

NASA Astrophysics Data System (ADS)

Loeper, C. Paul

Due to increased ignition delay and volatility, low temperature combustion (LTC) research utilizing gasoline fuel has experienced recent interest [1-3]. These characteristics improve air-fuel mixing prior to ignition allowing for reduced emissions of nitrogen oxides (NOx) and soot (or particulate matter, PM). Computational fluid dynamics (CFD) results at the University of Wisconsin-Madison's Engine Research Center (Ra et al. [4, 5]) have validated these attributes and established baseline operating parameters for a gasoline compression ignition (GCI) concept in a light-duty diesel engine over a large load range (3-16 bar net IMEP). In addition to validating these computational results, subsequent experiments at the Engine Research Center utilizing a single cylinder research engine based on a GM 1.9-liter diesel engine have progressed fundamental understanding of gasoline autoignition processes, and established the capability of critical controlling input parameters to better control GCI operation. The focus of this thesis can be divided into three segments: 1) establishment of operating requirements in the low-load operating limit, including operation sensitivities with respect to inlet temperature, and the capabilities of injection strategy to minimize NOx emissions while maintaining good cycle-to-cycle combustion stability; 2) development of novel three-injection strategies to extend the high load limit; and 3) having developed fundamental understanding of gasoline autoignition kinetics, and how changes in physical processes (e.g. engine speed effects, inlet pressure variation, and air-fuel mixture processes) affects operation, develop operating strategies to maintain robust engine operation. Collectively, experimental results have demonstrated the ability of GCI strategies to operate over a large load-speed range (3 bar to 17.8 bar net IMEP and 1300-2500 RPM, respectively) with low emissions (NOx and PM less than 1 g/kg-FI and 0.2 g/kg-FI, respectively), and low fuel consumption (gross indicated fuel consumption <200 g/kWh). [1] Dec, J. E., Yang, Y., and Dronniou, N., 2011, "Boosted HCCI - Controlling Pressure- Rise Rates for Performance Improvements using Partial Fuel Stratification with Conventional Gasoline," SAE Int. J. Engines, 4(1), pp. 1169-1189. [2] Kalghatgi, G., Hildingsson, L., and Johansson, B., 2010, "Low NO(x) and Low Smoke Operation of a Diesel Engine Using Gasolinelike Fuels," Journal of Engineering for Gas Turbines and Power-Transactions of the Asme, 132(9), p. 9. [3] Manente, V., Zander, C.-G., Johansson, B., Tunestal, P., and Cannella, W., 2010, "An Advanced Internal Combustion Engine Concept for Low Emissions and High Efficiency from Idle to Max Load Using Gasoline Partially Premixed Combustion," SAE International, 2010-01-2198. [4] Ra, Y., Loeper, P., Reitz, R., Andrie, M., Krieger, R., Foster, D., Durrett, R., Gopalakrishnan, V., Plazas, A., Peterson, R., and Szymkowicz, P., 2011, "Study of High Speed Gasoline Direct Injection Compression Ignition (GDICI) Engine Operation in the LTC Regime," SAE Int. J. Engines, 4(1), pp. 1412-1430. [5] Ra, Y., Loeper, P., Andrie, M., Krieger, R., Foster, D., Reitz, R., and Durrett, R., 2012, "Gasoline DICI Engine Operation in the LTC Regime Using Triple- Pulse Injection," SAE Int. J. Engines, 5(3), pp. 1109-1132.

Jet engine performance enhancement through use of a wave-rotor topping cycle

NASA Technical Reports Server (NTRS)

Wilson, Jack; Paxson, Daniel E.

1993-01-01

A simple model is used to calculate the thermal efficiency and specific power of simple jet engines and jet engines with a wave-rotor topping cycle. The performance of the wave rotor is based on measurements from a previous experiment. Applied to the case of an aircraft flying at Mach 0.8, the calculations show that an engine with a wave rotor topping cycle may have gains in thermal efficiency of approximately 1 to 2 percent and gains in specific power of approximately 10 to 16 percent over a simple jet engine with the same overall compression ratio. Even greater gains are possible if the wave rotor's performance can be improved.

High Chromium Cast Irons: Destabilized-Subcritical Secondary Carbide Precipitation and Its Effect on Hardness and Wear Properties

NASA Astrophysics Data System (ADS)

Guitar, María Agustina; Suárez, Sebastián; Prat, Orlando; Duarte Guigou, Martín; Gari, Valentina; Pereira, Gastón; Mücklich, Frank

2018-05-01

This work evaluates the effect of a destabilization treatment combined with a subcritical diffusion (SCD) and a subsequent quenching (Q) steps on precipitation of secondary carbides and their influence on the wear properties of HCCI (16%Cr). The destabilization of the austenite at high temperature leads to a final microstructure composed of eutectic and secondary carbides, with an M7C3 nature, embedded in a martensitic matrix. An improved wear resistance was observed in the SCD + Q samples in comparison with the Q one, which was attributed to the size of secondary carbides.

Reaction kinetics of hydrogen atom abstraction from isopentanol by the H atom and HO2˙ radical.

PubMed

Parab, Prajakta Rajaram; Heufer, K Alexander; Fernandes, Ravi Xavier

2018-04-25

Isopentanol is a potential next-generation biofuel for future applications to Homogeneous Charge Compression Ignition (HCCI) engine concepts. To provide insights into the combustion behavior of isopentanol, especially to its auto-ignition behavior which is linked both to efficiency and pollutant formation in real combustion systems, detailed quantum chemical studies for crucial reactions are desired. H-Abstraction reaction rates from fuel molecules are key initiation steps for chain branching required for auto-ignition. In this study, rate constants are determined for the hydrogen atom abstraction reactions from isopentanol by the H atom and HO2˙ radical by implementing the CBS-QB3 composite method. For the treatment of the internal rotors, a Pitzer-Gwinn-like approximation is applied. On comparing the computed reaction energies, the highest exothermicity (ΔE = -46 kJ mol-1) is depicted for Hα abstraction by the H atom whereas the lowest endothermicity (ΔE = 29 kJ mol-1) is shown for the abstraction of Hα by the HO2˙ radical. The formation of hydrogen bonding is found to affect the kinetics of the H atom abstraction reactions by the HO2˙ radical. Further above 750 K, the calculated high pressure limit rate constants indicate that the total contribution from delta carbon sites (Cδ) is predominant for hydrogen atom abstraction by the H atom and HO2˙ radical.

Everyday Engineering: What Makes a Bic Click?

ERIC Educational Resources Information Center

Moyer, Richard; Everett, Susan

2009-01-01

The ballpoint pen is an ideal example of simple engineering that we use everyday. But is it really so simple? The ballpoint pen is a remarkable combination of technology and science. Its operation uses several scientific principles related to chemistry and physics, such as properties of liquids and simple machines. They represent significant…

Constructing an Engineering Model for Raising an Egyptian Obelisk

ERIC Educational Resources Information Center

Beck, Charles R.

2009-01-01

One of the greatest mysteries of ancient times is how the Egyptians managed to raise huge obelisks using very simple technology. This remarkable task has puzzled engineers for thousand of years. After failing to raise an obelisk with simple machines, such as levers and pulleys, a team of modern engineers solved the mystery using a sandpit and the…

A simple performance calculation method for LH2/LOX engines with different power cycles

NASA Technical Reports Server (NTRS)

Schmucker, R. H.

1973-01-01

A simple method for the calculation of the specific impulse of an engine with a gas generator cycle is presented. The solution is obtained by a power balance between turbine and pump. Approximate equations for the performance of the combustion products of LH2/LOX are derived. Performance results are compared with solutions of different engine types.

Thermodynamics of a Simple Rubber-Band Heat Engine

ERIC Educational Resources Information Center

Mullen, J. G.; And Others

1975-01-01

Outlines the basic engine design and nomenclature, develops some relations between the state parameters of the rubber-band system, defines engine efficiency, and compares the Archibald engine with the Carnot engine. (GS)

Investigating the impact of a LEGO(TM)-based, engineering-oriented curriculum compared to an inquiry-based curriculum on fifth graders' content learning of simple machines

NASA Astrophysics Data System (ADS)

Marulcu, Ismail

This mixed method study examined the impact of a LEGO-based, engineering-oriented curriculum compared to an inquiry-based curriculum on fifth graders' content learning of simple machines. This study takes a social constructivist theoretical stance that science learning involves learning scientific concepts and their relations to each other. From this perspective, students are active participants, and they construct their conceptual understanding through the guidance of their teacher. With the goal of better understanding the use of engineering education materials in classrooms the National Academy of Engineering and National Research Council in the book "Engineering in K-12 Education" conducted an in-depth review of the potential benefits of including engineering in K--12 schools as (a) improved learning and achievement in science and mathematics, (b) increased awareness of engineering and the work of engineers, (c) understanding of and the ability to engage in engineering design, (d) interest in pursuing engineering as a career, and (e) increased technological literacy (Katehi, Pearson, & Feder, 2009). However, they also noted a lack of reliable data and rigorous research to support these assertions. Data sources included identical written tests and interviews, classroom observations and videos, teacher interviews, and classroom artifacts. To investigate the impact of the design-based simple machines curriculum compared to the scientific inquiry-based simple machines curriculum on student learning outcomes, I compared the control and the experimental groups' scores on the tests and interviews by using ANCOVA. To analyze and characterize the classroom observation videotapes, I used Jordan and Henderson's (1995) method and divide them into episodes. My analyses revealed that the design-based Design a People Mover: Simple Machines unit was, if not better, as successful as the inquiry-based FOSS Levers and Pulleys unit in terms of students' content learning. I also found that students in the engineering group outperformed students in the control group in regards to their ability to answer open-ended questions when interviewed. Implications for students' science content learning and teachers' professional development are discussed.

High-Performance Liquid Chromatography in the Undergraduate Chemical Engineering Laboratory

ERIC Educational Resources Information Center

Frey, Douglas D.; Guo, Hui; Karnik, Nikhila

2013-01-01

This article describes the assembly of a simple, low-cost, high-performance liquid chromatography (HPLC) system and its use in the undergraduate chemical engineering laboratory course to perform simple experiments. By interpreting the results from these experiments students are able to gain significant experience in the general method of…

21. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model no. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. Steam-feed pipe at top left of engine. Steam exhaust pipe leaves base of engine on right end and projects upwards. The boiler feed and supply pipe running water through the engine's pre-heat system are seen running to the lower left end of the engine. Pulley in the foreground was not used. The centrifugals were powered by a belt running from the flywheel in the background. Ball-type governor and pulley are on left end of the engine. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Modeling of hybrid vehicle fuel economy and fuel engine efficiency

NASA Astrophysics Data System (ADS)

Wu, Wei

"Near-CV" (i.e., near-conventional vehicle) hybrid vehicles, with an internal combustion engine, and a supplementary storage with low-weight, low-energy but high-power capacity, are analyzed. This design avoids the shortcoming of the "near-EV" and the "dual-mode" hybrid vehicles that need a large energy storage system (in terms of energy capacity and weight). The small storage is used to optimize engine energy management and can provide power when needed. The energy advantage of the "near-CV" design is to reduce reliance on the engine at low power, to enable regenerative braking, and to provide good performance with a small engine. The fuel consumption of internal combustion engines, which might be applied to hybrid vehicles, is analyzed by building simple analytical models that reflect the engines' energy loss characteristics. Both diesel and gasoline engines are modeled. The simple analytical models describe engine fuel consumption at any speed and load point by describing the engine's indicated efficiency and friction. The engine's indicated efficiency and heat loss are described in terms of several easy-to-obtain engine parameters, e.g., compression ratio, displacement, bore and stroke. Engine friction is described in terms of parameters obtained by fitting available fuel measurements on several diesel and spark-ignition engines. The engine models developed are shown to conform closely to experimental fuel consumption and motored friction data. A model of the energy use of "near-CV" hybrid vehicles with different storage mechanism is created, based on simple algebraic description of the components. With powertrain downsizing and hybridization, a "near-CV" hybrid vehicle can obtain a factor of approximately two in overall fuel efficiency (mpg) improvement, without considering reductions in the vehicle load.

A Simple Experiment for Teaching Process Intensification by Static Mixing in Chemical Reaction Engineering

ERIC Educational Resources Information Center

Baz-Rodríguez, Sergio; Herrera-Soberanis, Natali; Rodríguez-Novelo, Miguel; Guillén-Francisc, Juana; Rocha-Uribe, José

2016-01-01

An experiment for teaching mixing intensification in reaction engineering is described. For this, a simple tubular reactor was constructed; helical static mixer elements were fabricated from stainless steel strips and inserted into the reactor. With and without the internals, the equipment operates as a static mixer reactor or a laminar flow…

Class and Home Problems: Humidification, a True "Home" Problem for p. Chemical Engineer

ERIC Educational Resources Information Center

Condoret, Jean-Stephane

2012-01-01

The problem of maintaining hygrothermal comfort in a house is addressed using the chemical engineer's toolbox. A simple dynamic modelling proved to give a good description of the humidification of the house in winter, using a domestic humidifier. Parameters of the model were identified from a simple experiment. Surprising results, especially…

Micro to Nanoscale Engineering of Surface Precipitates Using Reconfigurable Contact Lines.

PubMed

Kabi, Prasenjit; Chaudhuri, Swetaprovo; Basu, Saptarshi

2018-02-06

Nanoscale engineering has traditionally adopted the chemical route of synthesis or optochemical techniques such as lithography requiring large process times, expensive equipment, and an inert environment. Directed self-assembly using evaporation of nanocolloidal droplet can be a potential low-cost alternative across various industries ranging from semiconductors to biomedical systems. It is relatively simple to scale and reorient the evaporation-driven internal flow field in an evaporating droplet which can direct dispersed matter into functional agglomerates. The resulting functional precipitates not only exhibit macroscopically discernible changes but also nanoscopic variations in the particulate assembly. Thus, the evaporating droplet forms an autonomous system for nanoscale engineering without the need for external resources. In this article, an indigenous technique of interfacial re-engineering, which is both simple and inexpensive to implement, is developed. Such re-engineering widens the horizon for surface patterning previously limited by the fixed nature of the droplet interface. It involves handprinting hydrophobic lines on a hydrophilic substrate to form a confinement of any selected geometry using a simple document stamp. Droplets cast into such confinements get modulated into a variety of shapes. The droplet shapes control the contact line behavior, evaporation dynamics, and complex internal flow pattern. By exploiting the dynamic interplay among these variables, we could control the deposit's macro- as well as nanoscale assembly not possible with simple circular droplets. We provide a detailed mechanism of the coupling at various length scales enabling a predictive capability in custom engineering, particularly useful in nanoscale applications such as photonic crystals.

A simplified life-cycle cost comparison of various engines for small helicopter use

NASA Technical Reports Server (NTRS)

Civinskas, K. C.; Fishbach, L. M.

1974-01-01

A ten-year, life-cycle cost comparison is made of the following engines for small helicopter use: (1) simple turboshaft; (2) regenerative turboshaft; (3) compression-ignition reciprocator; (4) spark-ignited rotary; and (5) spark-ignited reciprocator. Based on a simplified analysis and somewhat approximate data, the simple turboshaft engine apparently has the lowest costs for mission times up to just under 2 hours. At 2 hours and above, the regenerative turboshaft appears promising. The reciprocating and rotary engines are less attractive, requiring from 10 percent to 80 percent more aircraft to have the same total payload capability as a given number of turbine powered craft. A nomogram was developed for estimating total costs of engines not covered in this study.

Prediction of the Main Engine Power of a New Container Ship at the Preliminary Design Stage

NASA Astrophysics Data System (ADS)

Cepowski, Tomasz

2017-06-01

The paper presents mathematical relationships that allow us to forecast the estimated main engine power of new container ships, based on data concerning vessels built in 2005-2015. The presented approximations allow us to estimate the engine power based on the length between perpendiculars and the number of containers the ship will carry. The approximations were developed using simple linear regression and multivariate linear regression analysis. The presented relations have practical application for estimation of container ship engine power needed in preliminary parametric design of the ship. It follows from the above that the use of multiple linear regression to predict the main engine power of a container ship brings more accurate solutions than simple linear regression.

Small Engine Component Technology (SECT) study

NASA Technical Reports Server (NTRS)

Larkin, T. R.

1986-01-01

The objective of this study is to identify high payoff technologies for year 2000 small gas turbine engines, and to provide a technology plan to guide research and technology efforts toward revolutionizing the small gas turbine technology base. The goal is to define the required technology to provide a 30 percent reduction in mission fuel burned, to reduce direct operating costs by at least 10 percent, and to provide increased reliability and durability of the gas turbine propulsion system. The baseline established to evaluate the year 2000 technology base was an 8-passenger commercial tilt-rotor aircraft powered by a current technology gas turbine engine. Three basic engine cycles were studied: the simple cycle engine, a waste heat recovery cycle, and a wave rotor engine cycle. For the simple cycle engine, two general arrangements were considered: the traditional concentric spool arrangement and a nonconcentric spool arrangement. Both a regenerative and a recuperative cycle were studied for the waste heat recovery cycle.

A Simple Interactive Introduction to Teaching Genetic Engineering

ERIC Educational Resources Information Center

Child, Paula

2013-01-01

In the UK, at key stage 4, students aged 14-15 studying GCSE Core Science or Unit 1 of the GCSE Biology course are required to be able to describe the process of genetic engineering to produce bacteria that can produce insulin. The simple interactive introduction described in this article allows students to consider the problem, devise a model and…

Using Mung Beans as a Simple, Informative Means to Evaluate the Phytotoxicity of Engineered Nanomaterials and Introduce the Concept of Nanophytotoxicity to Undergraduate Students

ERIC Educational Resources Information Center

Ross, Shailise S.; Owen, Matthew J.; Pedersen, Brian P.; Liu, Gang-yu; Miller, William J. W.

2016-01-01

This work presents a lecture and lab series that focuses on teaching the concept of nanophytotoxicity to undergraduate students in a relatively simple experiment. In this experiment, students evaluated the phytotoxicity of engineered nanomaterials (ENMs) using mung beans (i.e., "Vigna radiata") and industrially relevant, commercially…

Demonstration and Assessment of a Simple Viscosity Experiment for High School Science Classes

ERIC Educational Resources Information Center

Floyd­-Smith, T. M.; Kwon, K. C.; Burmester, J. A.; Dale, F. F.; Vahdat, N.; Jones, P.

2006-01-01

The demonstration of a simple viscosity experiment for high school classes was conducted and assessed. The purpose of the demonstration was to elicit the interest of high school juniors and seniors in the field of chemical engineering. The demonstration consisted of a discussion on both engineering and the concept of viscosity as well as a…

Fifth Graders' Learning About Simple Machines Through Engineering Design-Based Instruction Using LEGO™ Materials

NASA Astrophysics Data System (ADS)

Marulcu, Ismail; Barnett, Mike

2013-10-01

This study is part of a 5-year National Science Foundation-funded project, Transforming Elementary Science Learning Through LEGO™ Engineering Design. In this study, we report on the successes and challenges of implementing an engineering design-based and LEGO™-oriented unit in an urban classroom setting and we focus on the impact of the unit on students' content understanding of simple machines. The LEGO™ engineering-based simple machines module, which was developed for fifth graders by our research team, was implemented in an urban school in a large city in the Northeastern region of the USA. Thirty-three fifth grade students participated in the study, and they showed significant growth in content understanding. We measured students' content knowledge by using identical paper tests and semistructured interviews before and after instruction. Our paired t test analysis results showed that students significantly improved their test and interview scores (t = -3.62, p < 0.001 for multiple-choice items and t = -9.06, p < 0.000 for the open-ended items in the test and t = -12.11, p < 0.000 for the items in interviews). We also identified several alternative conceptions that are held by students on simple machines.

Dynamic Characteristics of Simple Cylindrical Hydraulic Engine Mount Utilizing Air Compressibility

NASA Astrophysics Data System (ADS)

Nakahara, Kazunari; Nakagawa, Noritoshi; Ohta, Katsutoshi

A cylindrical hydraulic engine mount with simple construction has been developed. This engine mount has a sub chamber formed by utilizing air compressibility without a diaphragm. A mathematical model of the mount is presented to predict non-linear dynamic characteristics in consideration of the effect of the excitation amplitude on the storage stiffness and loss factor. The mathematical model predicts experimental results well for the frequency responses of the storage stiffness and loss factor over the frequency range of 5 Hz to 60Hz. The effect of air volume and internal pressure on the dynamic characteristics is clarified by the analysis and dynamic characterization testing. The effectiveness of the cylindrical hydraulic engine mount on the reduction of engine shake is demonstrated for riding comfort through on-vehicle testing with a chassis dynamometer.

Investigating the Impact of a LEGO(TM)-Based, Engineering-Oriented Curriculum Compared to an Inquiry-Based Curriculum on Fifth Graders' Content Learning of Simple Machines

ERIC Educational Resources Information Center

Marulcu, Ismail

2010-01-01

This mixed method study examined the impact of a LEGO-based, engineering-oriented curriculum compared to an inquiry-based curriculum on fifth graders' content learning of simple machines. This study takes a social constructivist theoretical stance that science learning involves learning scientific concepts and their relations to each other. From…

Toward a Definition of the Engineering Method.

ERIC Educational Resources Information Center

Koen, Billy Vaughn

1984-01-01

Defines the engineering method by: (1) giving a preliminary definition and examples of its essential term (heuristics); (2) comparing the definition to a popular alternative; and (3) presenting a simple form of the definition. This definition states that the engineering method is the use of engineering heuristics. (JN)

Impact of an engineering design-based curriculum compared to an inquiry-based curriculum on fifth graders' content learning of simple machines

NASA Astrophysics Data System (ADS)

Marulcu, Ismail; Barnett, Michael

2016-01-01

Background: Elementary Science Education is struggling with multiple challenges. National and State test results confirm the need for deeper understanding in elementary science education. Moreover, national policy statements and researchers call for increased exposure to engineering and technology in elementary science education. The basic motivation of this study is to suggest a solution to both improving elementary science education and increasing exposure to engineering and technology in it. Purpose/Hypothesis: This mixed-method study examined the impact of an engineering design-based curriculum compared to an inquiry-based curriculum on fifth graders' content learning of simple machines. We hypothesize that the LEGO-engineering design unit is as successful as the inquiry-based unit in terms of students' science content learning of simple machines. Design/Method: We used a mixed-methods approach to investigate our research questions; we compared the control and the experimental groups' scores from the tests and interviews by using Analysis of Covariance (ANCOVA) and compared each group's pre- and post-scores by using paired t-tests. Results: Our findings from the paired t-tests show that both the experimental and comparison groups significantly improved their scores from the pre-test to post-test on the multiple-choice, open-ended, and interview items. Moreover, ANCOVA results show that students in the experimental group, who learned simple machines with the design-based unit, performed significantly better on the interview questions. Conclusions: Our analyses revealed that the design-based Design a people mover: Simple machines unit was, if not better, as successful as the inquiry-based FOSS Levers and pulleys unit in terms of students' science content learning.

8. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model No. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. It received steam from the locomotive type, fire-tube portable boiler in the background. The engine's water pump which pumped water from the feed-water clarifying cistern, in between the boiler and engine, through a pre-heat system and on to the boiler, is seen in front of the fluted cylinder. The fly-ball governor, missing its balls, the steam port, and manual throttle valve are above and behind the cylinder. The flywheel, drive shaft, and pulley are on the left side of the engine bed. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Rocket Engine Oscillation Diagnostics

NASA Technical Reports Server (NTRS)

Nesman, Tom; Turner, James E. (Technical Monitor)

2002-01-01

Rocket engine oscillating data can reveal many physical phenomena ranging from unsteady flow and acoustics to rotordynamics and structural dynamics. Because of this, engine diagnostics based on oscillation data should employ both signal analysis and physical modeling. This paper describes an approach to rocket engine oscillation diagnostics, types of problems encountered, and example problems solved. Determination of design guidelines and environments (or loads) from oscillating phenomena is required during initial stages of rocket engine design, while the additional tasks of health monitoring, incipient failure detection, and anomaly diagnostics occur during engine development and operation. Oscillations in rocket engines are typically related to flow driven acoustics, flow excited structures, or rotational forces. Additional sources of oscillatory energy are combustion and cavitation. Included in the example problems is a sampling of signal analysis tools employed in diagnostics. The rocket engine hardware includes combustion devices, valves, turbopumps, and ducts. Simple models of an oscillating fluid system or structure can be constructed to estimate pertinent dynamic parameters governing the unsteady behavior of engine systems or components. In the example problems it is shown that simple physical modeling when combined with signal analysis can be successfully employed to diagnose complex rocket engine oscillatory phenomena.

Seismic Methods

EPA Pesticide Factsheets

Seismic methods are the most commonly conducted geophysical surveys for engineering investigations. Seismic refraction provides engineers and geologists with the most basic of geologic data via simple procedures with common equipment.

Seismic Reflection Methods

EPA Pesticide Factsheets

Seismic methods are the most commonly conducted geophysical surveys for engineering investigations. Seismic refraction provides engineers and geologists with the most basic of geologic data via simple procedures with common equipment.

Student Conceptions of Simple Circuits.

ERIC Educational Resources Information Center

Fredette, Norman; Lochhead, John

1980-01-01

Investigates some conceptual difficulties which college students have with regard to simple direct current circuits. The clinical interview technique was used with 57 students in a freshman level engineering course. (HM)

A simple method of calculating Stirling engines for engine design optimization

NASA Technical Reports Server (NTRS)

Martini, W. R.

1978-01-01

A calculation method is presented for a rhombic drive Stirling engine with a tubular heater and cooler and a screen type regenerator. Generally the equations presented describe power generation and consumption and heat losses. It is the simplest type of analysis that takes into account the conflicting requirements inherent in Stirling engine design. The method itemizes the power and heat losses for intelligent engine optimization. The results of engine analysis of the GPU-3 Stirling engine are compared with more complicated engine analysis and with engine measurements.

An Overview of Advanced Concepts for Space Access (Preprint)

DTIC Science & Technology

2008-06-19

One such technology is the pulsed detonation engine ( PDE ). PDEs are conceptually simple devices. Fuel and air are mixed in the closed end of a...to form air detonations that propel the vehicle. Two types of lightcraft engines have been examined using either simple laser-thermal or more complex... detonation waves to propel the vehicle has the advantage of not having to store fuel on-board the vehicle. However as the vehicle ascends, the air

Emergency Fuels Technology

DTIC Science & Technology

1982-06-01

starting and running in multifuel engines. D. FEF for Ground Turbine Engines Operation of the simple-cycle, gas-turbine engine is based on the Brayton or...MR R LAYNE) CAMERON STATION WASHINGTON DC 20362 ALEXANDRIA VA 22314 CDR CDR DAVID TAYLOR NAVAL SHIP R&D CTR MARINE CORPS LOGISTICS SUPPORT CODE 2830

Design of automatic startup and shutdown logic for a Brayton-cycle 2- to 15-kilowatt engine

NASA Technical Reports Server (NTRS)

Vrancik, J. E.; Bainbridge, R. C.

1975-01-01

The NASA Lewis Research Center is conducting a closed-Brayton-cycle power conversion system technology program in which a complete power system (engine) has been designed and demonstrated. This report discusses the design of automatic startup and shutdown logic circuits as a modification to the control system presently used in this demonstration engine. This modification was primarily intended to make starting the engine as simple and safe as possible and to allow the engine to be run unattended. In the modified configuration the engine is started by turning the control console power on and pushing the start button after preheating the gas loop. No other operator action is required to effect a complete startup. Shutdown, if one is required, is also effected by a simple stop button. The automatic startup and shutdown of the engine have been successfully and purposefully demonstrated more than 50 times at the Lewis Research Center during 10,000 hours of unattended operation. The net effect of this modification is an engine that can be safely started and stopped by relatively untrained personnel. The approach lends itself directly to remote unattended operation.

Slope stabilization guide for Minnesota local government engineers.

DOT National Transportation Integrated Search

2017-06-01

This user guide provides simple, costeffective methods for stabilizing locally maintained slopes along roadways in Minnesota. Eight slope stabilization techniques are presented that local government engineers can undertake using locally available ...

A Simple Combinatorial Codon Mutagenesis Method for Targeted Protein Engineering.

PubMed

Belsare, Ketaki D; Andorfer, Mary C; Cardenas, Frida S; Chael, Julia R; Park, Hyun June; Lewis, Jared C

2017-03-17

Directed evolution is a powerful tool for optimizing enzymes, and mutagenesis methods that improve enzyme library quality can significantly expedite the evolution process. Here, we report a simple method for targeted combinatorial codon mutagenesis (CCM). To demonstrate the utility of this method for protein engineering, CCM libraries were constructed for cytochrome P450 BM3 , pfu prolyl oligopeptidase, and the flavin-dependent halogenase RebH; 10-26 sites were targeted for codon mutagenesis in each of these enzymes, and libraries with a tunable average of 1-7 codon mutations per gene were generated. Each of these libraries provided improved enzymes for their respective transformations, which highlights the generality, simplicity, and tunability of CCM for targeted protein engineering.

System Engineering for J-2X Development: The Simpler, the Better

NASA Technical Reports Server (NTRS)

Kelly, William M.; Greasley, Paul; Greene, William D.; Ackerman, Peter

2008-01-01

The Ares I and Ares V Vehicles will utilize the J-2X rocket engine developed for NASA by the Pratt and Whitney Rocketdyne Company (PWR) as the upper stage engine (USE). The J-2X is an improved higher power version of the original J-2 engine used for Apollo. System Engineering (SE) facilitates direct and open discussions of issues and problems. This simple idea is often overlooked in large, complex engineering development programs. Definition and distribution of requirements from the engine level to the component level is controlled by Allocation Reports which breaks down numerical design objectives (weight, reliability, etc.) into quanta goals for each component area. Linked databases of design and verification requirements help eliminate redundancy and potential mistakes inherent in separated systems. Another tool, the Architecture Design Description (ADD), is used to control J-2X system architecture and effectively communicate configuration changes to those involved in the design process. But the proof of an effective process is in successful program accomplishment. SE is the methodology being used to meet the challenge of completing J-2X engine certification 2 years ahead of any engine program ever developed at PWR. This paper describes the simple, better SE tools and techniques used to achieve this success.

Simple Signaling Molecules for Inductive Bone Regenerative Engineering

PubMed Central

Nelson, Stephen J.; Deng, Meng; Sethuraman, Swaminathan; Doty, Stephen B.; Lo, Kevin W. H.; Khan, Yusuf M.; Laurencin, Cato T.

2014-01-01

With greater than 500,000 orthopaedic procedures performed in the United States each year requiring a bone graft, the development of novel graft materials is necessary. We report that some porous polymer/ceramic composite scaffolds possess intrinsic osteoinductivity as shown through their capacity to induce in vivo host osteoid mineralization and in vitro stem cell osteogenesis making them attractive synthetic bone graft substitutes. It was discovered that certain low crystallinity ceramics partially dissociate into simple signaling molecules (i.e., calcium and phosphate ions) that induce stem cells to endogenously produce their own osteoinductive proteins. Review of the literature has uncovered a variety of simple signaling molecules (i.e., gases, ions, and redox reagents) capable of inducing other desirable stem cell differentiation through endogenous growth factor production. Inductive simple signaling molecules, which we have termed inducerons, represent a paradigm shift in the field of regenerative engineering where they can be utilized in place of recombinant protein growth factors. PMID:25019622

Engineering Encounters: Sailing into the Digital Era

ERIC Educational Resources Information Center

Bellavance, Janet; Truchon, Amy

2015-01-01

This article describes how Janet Bellavance teamed with technology integration specialist, Amy Truchon to incorporate iPads into her Engineering is Elementary (EiE) unit--a curriculum that engages elementary students in engineering simple technologies. In an EiE unit, students design, test, and then, based on test results, improve their design,…

Thrust and Propulsive Efficiency from an Instructive Viewpoint

ERIC Educational Resources Information Center

Kaufman, Richard D.

2010-01-01

In a typical engineering or physics curriculum, the momentum equation is used for the determination of jet engine thrust. Even a simple thrust analysis requires a heavy emphasis on mathematics that can cause students and engineers to lose a physical perspective on thrust. This article provides for this physical understanding using only static…

A Basic Comparison of the Space Shuttle Main Engine and the J-2X Engine

NASA Technical Reports Server (NTRS)

Ayer, Adam

2007-01-01

With the introduction of the new manned space effort through the Constellation Program, there is an interest to have a basic comparison of the current Space Shuttle Main Engine (SSME) to the J-2X engine used for the second stage of both the Ares I and Ares V rockets. This paper seeks to compare size, weight and thrust capabilities while drawing simple conclusions on differences between the two engines.

A Course for All Students: Foundations of Modern Engineering

ERIC Educational Resources Information Center

Best, Charles L.

1971-01-01

Describes a course for non-engineering students at Lafayette College which includes the design process in a project. Also included are the study of modeling, optimization, simulation, computer application, and simple feedback controls. (Author/TS)

Introducing Students to Basic ChE Concepts: Four Simple Experiments.

ERIC Educational Resources Information Center

Fraser, Duncan M.

1999-01-01

Describes an Introduction to Chemical Engineering course with particular reference to the development, use, and evaluation of four simple experiments centered around the fundamental principles of heat transfer, mass transfer, reaction kinetics, and momentum transfer. (WRM)

Making Work: Demonstrating Thermodynamic Concepts with Solar-Powered Wax and Rubber Heat Engines

ERIC Educational Resources Information Center

Appleyard, S. J.

2007-01-01

Construction details are provided for simple heat engines that use candle wax and elastomers as working substances. The engines are constructed using common household materials and can be easily constructed in a school classroom or at home. They work reliably and are useful tools for demonstrating the conversion of heat to mechanical work. They…

Engineering-Based Problem Solving in the Middle School: Design and Construction with Simple Machines

ERIC Educational Resources Information Center

English, Lyn D.; Hudson, Peter; Dawes, Les

2013-01-01

Incorporating engineering concepts into middle school curriculum is seen as an effective way to improve students' problem-solving skills. A selection of findings is reported from a science, technology, engineering and mathematics (STEM)-based unit in which students in the second year (grade 8) of a three-year longitudinal study explored…

Diesel Engine Services. An Instructor's Guide for a Program in Trade and Technical Education. Automotive Industries Occupations.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

Designed to prepare students to be engine mechanics working on automotive and large stationary diesel engines, this instructor's guide contains eight units arranged from simple to complex to facilitate student learning. Each contains behavioral objectives, a content outline, understandings and teaching approaches necessary to develop the content,…

Using the Two-Stroke Engine to Develop Technological Literacy

ERIC Educational Resources Information Center

Preble, Brian C.

2018-01-01

The two-stroke engine is an engineering marvel that has been incorporated into many aspects of modern-day life. While many seek to eliminate the two-stroke, others seek to revive this simple and effective power plant, aiming to make it more environmentally friendly and fuel-efficient. If successful, improvements could be far-reaching and…

DEER 2003 [Proceedings for the 9th Diesel Engine Emissions Reduction Workshop] RECORD FOR CD PREPARED BY OSTI

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

Overview: This was the ninth in a series of workshops that have evolved to conference status addressing Diesel Engine Emissions Reduction (DEER) technology. The initial three workshops were held biannually at the University of California, San Diego. Thereafter, as we alternated yearly between the sites Castine, Maine and Portsmouth, Virginia on the East Coast and San Diego on the West Coast, the workshops grew to conference status. This year we held the 9th DEER Conference, August 24 - 28, 2003, at the Newport Marriott in Newport, Rhode Island, in the Northeast States for Coordinated Air Use Management (NESCAUM) area. Wemore » had two objectives for DEER 2003: 1. To provide a forum to present transportation diesel engine developments and issues for the federal and state organizations involved with diesel engines as users, regulators, or supporters of research and development with the diesel engine manufacturers, their suppliers, the national laboratories, academia, human health effects, and the environmentally concerned public sector. 2. To make available European and U.S. personal-use diesel engine powered vehicles at our "Ride and Drive" for attendees and the press to see for themselves how far diesel engine technology had advanced. European diesel auto sales are rapidly approaching 50% of sales; and in France, 73% of luxury class vehicle buyers chose the diesel option. Banks Engineering and Cummins exhibited the "Sidewinder", a modified pick-up truck with a production in-line 6 cylinder Cummins B engine upgraded from 300 HP to more than 600 HP. This truck was officially clocked at the Bonneville test track at 222.139 mph. As a comparison, the $800,000 Ferrari Enzo, which is built to Formula 1 racing standards, has a projected top speed of 218 mph with its 12 cylinder gasoline engine. One can only imagine what the Ferrari Enzo could do fitted with a current technology diesel engine! Some of the highlights at DEER 2003 included the presentations by high-level managers at BMW and Mercedes Benz on their diesel engine development. Aaqius & Aaqius presented data and an exhibit of the latest PSA Peugeot fuel bound catalyst diesel particulate trap system. Cummins presented data regarding their compliance with EPA's Tier 2, Bin 5 standards on their V- 6, which was developed with DOE support. This was the first report of meeting these standards. Their next step is achieving durability. Caterpillar reported single cylinder engine steady-state tests of their HCCI injector that had engine out NOx levels under Tier 2, Bin 5. Two new approaches to particulate traps were reported by Accentus using non-thermal plasma and the University of Manchester's electrostatic precipitators. A Health Effects Session focused on U.S. and European testing of emissions from diesel and CNG buses. This session highlighted the need to use oxidation catalysts to reduce formaldehyde from CNG bus exhaust as CARB and Swedish testing indicated. A worthwhile dialogue was held with the Environmentalists Panel, which was organized and moderated by NESCAUM. The area that will produce the largest improvements in diesel engine efficiency will be the effective use of the roughly 60% of the energy in fuel that ends up as heat loss. Progress on the waste heat recovery using electric turbocompounding and thermoelectrics was reported. Quantum well confinement thermoelectrics investigators are reporting small specimens with a 400% increase in efficiency compared with current art bulk semiconductor thermoelectrics devices! Investigators of the electric turbocompounding concept for both light-truck and heavytruck applications are sorting out the problems with a commercial motor/alternators installed on the turbocharger shaft for both light- and heavy-duty trucks. These are but a few of the advances reported at DEER 2003. We were very fortunate to have such an outstanding group of presentations. We are planning to have DEER 2004 in San Diego,Coronado, actually,in August 2004. Hope to see you there! John Fairbanks Chair, DEER 2003« less

Research requirements for development of regenerative engines for helicopters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Semple, R.D.

1976-12-01

The improved specific fuel consumption of the regenerative engine was compared to a simple-cycle turboshaft engine. The performance improvement and fuel saving are obtained at the expense of increased engine weight, development and production costs, and maintenance costs. Costs and schedules are estimated for the elements of the research and development program. Interaction of the regenerative engine with other technology goals for an advanced civil helicopter is examined, including its impact on engine noise, hover and cruise performance, helicopter empty weight, drive-system efficiency and weight, one-engine-inoperative hover capability, and maintenance and reliability.

Research requirements for development of regenerative engines for helicopters

NASA Technical Reports Server (NTRS)

Semple, R. D.

1976-01-01

The improved specific fuel consumption of the regenerative engine was compared to a simple-cycle turboshaft engine. The performance improvement and fuel saving are obtained at the expense of increased engine weight, development and production costs, and maintenance costs. Costs and schedules are estimated for the elements of the research and development program. Interaction of the regenerative engine with other technology goals for an advanced civil helicopter is examined, including its impact on engine noise, hover and cruise performance, helicopter empty weight, drive-system efficiency and weight, one-engine-inoperative hover capability, and maintenance and reliability.

Electronic test and calibration circuits, a compilation

NASA Technical Reports Server (NTRS)

1972-01-01

A wide variety of simple test calibration circuits are compiled for the engineer and laboratory technician. The majority of circuits were found inexpensive to assemble. Testing electronic devices and components, instrument and system test, calibration and reference circuits, and simple test procedures are presented.

Fifth Graders' Learning about Simple Machines through Engineering Design-Based Instruction Using LEGO™ Materials

ERIC Educational Resources Information Center

Marulcu, Ismail; Barnett, Mike

2013-01-01

This study is part of a 5-year National Science Foundation-funded project, Transforming Elementary Science Learning Through LEGO™ Engineering Design. In this study, we report on the successes and challenges of implementing an engineering design-based and LEGO™-oriented unit in an urban classroom setting and we focus on the impact of the unit on…

Large deviation analysis of a simple information engine

NASA Astrophysics Data System (ADS)

Maitland, Michael; Grosskinsky, Stefan; Harris, Rosemary J.

2015-11-01

Information thermodynamics provides a framework for studying the effect of feedback loops on entropy production. It has enabled the understanding of novel thermodynamic systems such as the information engine, which can be seen as a modern version of "Maxwell's Dæmon," whereby a feedback controller processes information gained by measurements in order to extract work. Here, we analyze a simple model of such an engine that uses feedback control based on measurements to obtain negative entropy production. We focus on the distribution and fluctuations of the information obtained by the feedback controller. Significantly, our model allows an analytic treatment for a two-state system with exact calculation of the large deviation rate function. These results suggest an approximate technique for larger systems, which is corroborated by simulation data.

Effective Software Engineering Leadership for Development Programs

ERIC Educational Resources Information Center

Cagle West, Marsha

2010-01-01

Software is a critical component of systems ranging from simple consumer appliances to complex health, nuclear, and flight control systems. The development of quality, reliable, and effective software solutions requires the incorporation of effective software engineering processes and leadership. Processes, approaches, and methodologies for…

Effects of Structural Flexibility on Aircraft-Engine Mounts

NASA Technical Reports Server (NTRS)

Phillips, W. H.

1986-01-01

Analysis extends technique for design of widely used type of vibration-isolating mounts for aircraft engines, in which rubber mounting pads located in plane behind center of gravity of enginepropeller combination. New analysis treats problem in statics. Results of simple approach useful in providing equations for design of vibrationisolating mounts. Equations applicable in usual situation in which engine-mount structure itself relatively light and placed between large mass of engine and other heavy components of airplane.

In vitro corrosion and cytocompatibility properties of nano-whisker hydroxyapatite coating on magnesium alloy for bone tissue engineering applications.

PubMed

Yang, Huawei; Yan, Xueyu; Ling, Min; Xiong, Zuquan; Ou, Caiwen; Lu, Wei

2015-03-17

We report here the successful fabrication of nano-whisker hydroxyapatite (nHA) coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries.

In Vitro Corrosion and Cytocompatibility Properties of Nano-Whisker Hydroxyapatite Coating on Magnesium Alloy for Bone Tissue Engineering Applications

PubMed Central

Yang, Huawei; Yan, Xueyu; Ling, Min; Xiong, Zuquan; Ou, Caiwen; Lu, Wei

2015-01-01

We report here the successful fabrication of nano-whisker hydroxyapatite (nHA) coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries. PMID:25789500

Mystery of Foil Air Bearings for Oil-free Turbomachinery Unlocked: Load Capacity Rule-of-thumb Allows Simple Estimation of Performance

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher; Valco, Mark J.

2002-01-01

The Oil-Free Turbomachinery team at the NASA Glenn Research Center has unlocked one of the mysteries surrounding foil air bearing performance. Foil air bearings are self-acting hydrodynamic bearings that use ambient air, or any fluid, as their lubricant. In operation, the motion of the shaft's surface drags fluid into the bearing by viscous action, creating a pressurized lubricant film. This lubricating film separates the stationary foil bearing surface from the moving shaft and supports load. Foil bearings have been around for decades and are widely employed in the air cycle machines used for cabin pressurization and cooling aboard commercial jetliners. The Oil-Free Turbomachinery team is fostering the maturation of this technology for integration into advanced Oil-Free aircraft engines. Elimination of the engine oil system can significantly reduce weight and cost and could enable revolutionary new engine designs. Foil bearings, however, have complex elastic support structures (spring packs) that make the prediction of bearing performance, such as load capacity, difficult if not impossible. Researchers at Glenn recently found a link between foil bearing design and load capacity performance. The results have led to a simple rule-of-thumb that relates a bearing's size, speed, and design to its load capacity. Early simple designs (Generation I) had simple elastic (spring) support elements, and performance was limited. More advanced bearings (Generation III) with elastic supports, in which the stiffness is varied locally to optimize gas film pressures, exhibit load capacities that are more than double those of the best previous designs. This is shown graphically in the figure. These more advanced bearings have enabled industry to introduce commercial Oil-Free gas-turbine-based electrical generators and are allowing the aeropropulsion industry to incorporate the technology into aircraft engines. The rule-of-thumb enables engine and bearing designers to easily size and select bearing technology for a new application and determine the level of complexity required in the bearings. This new understanding enables industry to assess the feasibility of new engine designs and provides critical guidance toward the future development of Oil-Free turbomachinery propulsion systems.

Active Engine Mount Technology for Automobiles

NASA Technical Reports Server (NTRS)

Rahman, Z.; Spanos, J.

1996-01-01

We present a narrow-band tracking control using a variant of the Least Mean Square (LMS) algorithm [1,2,3] for supressing automobile engine/drive-train vibration disturbances. The algorithm presented here has a simple structure and may be implemented in a low cost micro controller.

Ranking protective coatings: Laboratory vs. field experience

NASA Astrophysics Data System (ADS)

Conner, Jeffrey A.; Connor, William B.

1994-12-01

Environmentally protective coatings are used on a wide range of gas turbine components for survival in the harsh operating conditions of engines. A host of coatings are commercially available to protect hot-section components, ranging from simple aluminides to designer metallic overlays and ceramic thermal barrier coatings. A variety of coating-application processes are available, and they range from simple pack cementation processing to complex physical vapor deposition, which requires multimillion dollar facilities. Detailed databases are available for most coatings and coating/process combinations for a range of laboratory tests. Still, the analysis of components actually used in engines often yields surprises when compared against predicted coating behavior from laboratory testing. This paper highlights recent work to develop new laboratory tests that better simulate engine environments. Comparison of in-flight coating performance as well as industrial and factory engine testing on a range of hardware is presented along with laboratory predictions from standard testing and from recently developed cyclic burner-rig testing.

Bio-based extraction and stabilization of anthocyanins.

PubMed

Roy, Anirban; Mukherjee, Rudra Palash; Howard, Luke; Beitle, Robert

2016-05-01

This work reports a novel method of recovering anthocyanin compounds from highly-pigmented grapes via a fermentation based approach. It was hypothesized that batch growth of Zymomonas mobilis on simple medium would produce both ethanol and enzymes/biomass-acting materials, the combination of which will provide a superior extraction when compared to simple alcohol extraction. To examine this hypothesis, Z. mobilis was fermented in a batch consisting of mashed Vitis vinifera and glucose, and the recovered anthocyanin pool was compared to that recovered via extraction with ethanol. Data indicated higher amounts of anthocyanins were recovered when compared to simple solvent addition. Additionally, the percent polymeric form of the anthocyanins could be manipulated by the level of aeration maintained in the fermentation. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:601-605, 2016. © 2016 American Institute of Chemical Engineers.

Understanding Trends in Autoignition of Biofuels: Homologous Series of Oxygenated C5 Molecules

DOE PAGES

Ciesielski, Peter N.; Robichaud, David J.; Kim, Seonah; ...

2017-07-05

Oxygenated biofuels provide a renewable, domestic source of energy that can enable adoption of advanced, high-efficiency internal combustion engines, such as those based on homogeneously charged compression ignition (HCCI). Of key importance to such engines is the cetane number (CN) of the fuel, which is determined by the autoignition of the fuel under compression at relatively low temperatures (550-800 K). For the plethora of oxygenated biofuels possible, it is desirable to know the ignition delay times and the CN of these fuels to help guide conversion strategies so as to focus efforts on the most desirable fuels. For alkanes, themore » chemical pathways leading to radical chain-branching reactions giving rise to low-temperature autoignition are well-known and are highly coincident with the buildup of reactive radicals such as OH. Key in the mechanisms leading to chain branching are the addition of molecular oxygen to alkyl radicals and the rearrangement and dissociation of the resulting peroxy radials. Prediction of the temperature and pressure dependence of reactions that lead to the buildup of reactive radicals requires a detailed understanding of the potential energy surfaces (PESs) of these reactions. In this study, we used quantum mechanical modeling to systematically compare the effects of oxygen functionalities on these PESs and associated kinetics so as to understand how they affect experimental trends in autoignition and CN. The molecules studied here include pentane, pentanol, pentanal, 2-heptanone, methylpentyl ether, methyl hexanoate, and pentyl acetate. All have a saturated five-carbon alkyl chain with an oxygen functional group attached to the terminal carbon atom. The results of our systematic comparison may be summarized as follows: (1) Oxygen functionalities activate C-H bonds by lowering the bond dissociation energy (BDE) relative to alkanes. (2) The R-OO bonds in peroxy radicals adjacent to carbonyl groups are weaker than corresponding alkyl systems, leading to dissociation of ROO radicals and reducing reactivity and hence CN. (3) Hydrogen atom transfer in peroxy radicals is important in autoignition, and low barriers for ethers and aldehydes lead to high CN. (4) Peroxy radicals formed from alcohols have low barriers to form aldehydes, which reduce the reactivity of the alkyl radical. In conclusion, these findings for the formation and reaction of alkyl radicals with molecular oxygen explain the trend in CN for these common biofuel functional groups.« less

Understanding Trends in Autoignition of Biofuels: Homologous Series of Oxygenated C5 Molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciesielski, Peter N.; Robichaud, David J.; Kim, Seonah

Oxygenated biofuels provide a renewable, domestic source of energy that can enable adoption of advanced, high-efficiency internal combustion engines, such as those based on homogeneously charged compression ignition (HCCI). Of key importance to such engines is the cetane number (CN) of the fuel, which is determined by the autoignition of the fuel under compression at relatively low temperatures (550-800 K). For the plethora of oxygenated biofuels possible, it is desirable to know the ignition delay times and the CN of these fuels to help guide conversion strategies so as to focus efforts on the most desirable fuels. For alkanes, themore » chemical pathways leading to radical chain-branching reactions giving rise to low-temperature autoignition are well-known and are highly coincident with the buildup of reactive radicals such as OH. Key in the mechanisms leading to chain branching are the addition of molecular oxygen to alkyl radicals and the rearrangement and dissociation of the resulting peroxy radials. Prediction of the temperature and pressure dependence of reactions that lead to the buildup of reactive radicals requires a detailed understanding of the potential energy surfaces (PESs) of these reactions. In this study, we used quantum mechanical modeling to systematically compare the effects of oxygen functionalities on these PESs and associated kinetics so as to understand how they affect experimental trends in autoignition and CN. The molecules studied here include pentane, pentanol, pentanal, 2-heptanone, methylpentyl ether, methyl hexanoate, and pentyl acetate. All have a saturated five-carbon alkyl chain with an oxygen functional group attached to the terminal carbon atom. The results of our systematic comparison may be summarized as follows: (1) Oxygen functionalities activate C-H bonds by lowering the bond dissociation energy (BDE) relative to alkanes. (2) The R-OO bonds in peroxy radicals adjacent to carbonyl groups are weaker than corresponding alkyl systems, leading to dissociation of ROO radicals and reducing reactivity and hence CN. (3) Hydrogen atom transfer in peroxy radicals is important in autoignition, and low barriers for ethers and aldehydes lead to high CN. (4) Peroxy radicals formed from alcohols have low barriers to form aldehydes, which reduce the reactivity of the alkyl radical. In conclusion, these findings for the formation and reaction of alkyl radicals with molecular oxygen explain the trend in CN for these common biofuel functional groups.« less

An analytical investigation of NO sub x control techniques for methanol fueled spark ignition engines

NASA Technical Reports Server (NTRS)

Browning, L. H.; Argenbright, L. A.

1983-01-01

A thermokinetic SI engine simulation was used to study the effects of simple nitrogen oxide control techniques on performance and emissions of a methanol fueled engine. As part of this simulation, a ring crevice storage model was formulated to predict UBF emissions. The study included spark retard, two methods of compression ratio increase and EGR. The study concludes that use of EGR in high turbulence, high compression engines will both maximize power and thermal efficiency while minimizing harmful exhaust pollutants.

A simple tagging system for protein encapsulation.

PubMed

Seebeck, Florian P; Woycechowsky, Kenneth J; Zhuang, Wei; Rabe, Jürgen P; Hilvert, Donald

2006-04-12

Molecular containers that encapsulate specific cargo can be useful for many natural and non-natural processes. We report a simple system, based on charge complementarity, for the encapsulation of appropriately tagged proteins within an engineered, proteinaceous capsid. Four negative charges per monomer were added to the lumazine synthase from Aquifex aeolicus (AaLS). The capsids formed by the engineered AaLS associate with green fluorescent protein bearing a positively charged deca-arginine tag upon coproduction in Escherichia coli. Analytical ultracentrifugation and scanning force microscopy studies indicated that the engineered AaLS retains the ability to form capsids, but that their average size was substantially increased. The success of this strategy demonstrates that both the container and guest components of protein-based encapsulation systems can be convergently designed in a straightforward manner, which may help to extend their versatility.

Teaching Sustainability Analysis in Electrical Engineering Lab Courses

ERIC Educational Resources Information Center

Braun, D.

2010-01-01

Laboratory courses represent an incompletely tapped opportunity to teach sustainability concepts. This work introduces and evaluates a simple strategy used to teach sustainability concepts in electrical engineering laboratory courses. The technique would readily adapt to other disciplines. The paper presents assessment data and a wiki containing…

Engineering a Classroom Discussion.

ERIC Educational Resources Information Center

Smith, Walter E.

1983-01-01

Describes physical science activities that civil/mechanical engineers (serving as resource persons) can use with students during units on force, work, center of gravity, simple machines, and other basic mechanics concepts. Activities are adapted from Career Oriented Modules to Explore Topics in Science for grades 5-9 (COMETS). (Author/JN)

Inquiry-Based Pre-Engineering Activities for K-4 Students

ERIC Educational Resources Information Center

Perrin, Michele

2004-01-01

This paper uses inquiry-based learning to introduce primary students to the concepts and terminology found in four introductory engineering courses: Differential Equations, Circuit Analysis, Thermodynamics, and Dynamics. Simple electronic sensors coupled with everyday objects, such as a troll doll, demonstrate and reinforce the physical principles…

Development of a Traditional/Computer-aided Graphics Course for Engineering Technology.

ERIC Educational Resources Information Center

Anand, Vera B.

1985-01-01

Describes a two-semester-hour freshman course in engineering graphics which uses both traditional and computerized instruction. Includes course description, computer graphics topics, and recommendations. Indicates that combining interactive graphics software with development of simple programs gave students a better foundation for upper-division…

Microfabrication of hierarchical structures for engineered mechanical materials

NASA Astrophysics Data System (ADS)

Vera Canudas, Marc

Materials found in nature present, in some cases, unique properties from their constituents that are of great interest in engineered materials for applications ranging from structural materials for the construction of bridges, canals and buildings to the fabrication of new lightweight composites for airplane and automotive bodies, to protective thin film coatings, amongst other fields. Research in the growing field of biomimetic materials indicates that the micro-architectures present in natural materials are critical to their macroscopic mechanical properties. A better understanding of the effect that structure and hierarchy across scales have on the material properties will enable engineered materials with enhanced properties. At the moment, very few theoretical models predict mechanical properties of simple materials based on their microstructures. Moreover these models are based on observations from complex biological systems. One way to overcome this challenge is through the use of microfabrication techniques to design and fabricate simple materials, more appropriate for the study of hierarchical organizations and microstructured materials. Arrays of structures with controlled geometry and dimension can be designed and fabricated at different length scales, ranging from a few hundred nanometers to centimeters, in order to mimic similar systems found in nature. In this thesis, materials have been fabricated in order to gain fundamental insight into the complex hierarchical materials found in nature and to engineer novel materials with enhanced mechanical properties. The materials fabricated here were mechanically characterized and compared to simple mechanics models to describe their behavior with the goal of applying the knowledge acquired to the design and synthesis of future engineered materials with novel properties.

Achieving Helicopter Modernization with Advanced Technology Turbine Engines

DTIC Science & Technology

1999-04-01

computer modeling of compressor and turbine aerody- digital engine control ( FADEC ) with manual backup. namics. Modern directionally solidified and single...controlled by a dual RAH.66A M channel FADEC , and features a very simple installation "" Improved Gross Weight and significantly reduced pilot...air separation efficiencies as an "advanced technology" engine. Technological meas- high as 97.5%. The FADEC improves acceleration, ures include but

Metabolic engineering of Saccharomyces cerevisiae for production of fatty acid-derived biofuels and chemicals.

PubMed

Runguphan, Weerawat; Keasling, Jay D

2014-01-01

As the serious effects of global climate change become apparent and access to fossil fuels becomes more limited, metabolic engineers and synthetic biologists are looking towards greener sources for transportation fuels. In recent years, microbial production of high-energy fuels by economically efficient bioprocesses has emerged as an attractive alternative to the traditional production of transportation fuels. Here, we engineered the budding yeast Saccharomyces cerevisiae to produce fatty acid-derived biofuels and chemicals from simple sugars. Specifically, we overexpressed all three fatty acid biosynthesis genes, namely acetyl-CoA carboxylase (ACC1), fatty acid synthase 1 (FAS1) and fatty acid synthase 2 (FAS2), in S. cerevisiae. When coupled to triacylglycerol (TAG) production, the engineered strain accumulated lipid to more than 17% of its dry cell weight, a four-fold improvement over the control strain. Understanding that TAG cannot be used directly as fuels, we also engineered S. cerevisiae to produce drop-in fuels and chemicals. Altering the terminal "converting enzyme" in the engineered strain led to the production of free fatty acids at a titer of approximately 400 mg/L, fatty alcohols at approximately 100mg/L and fatty acid ethyl esters (biodiesel) at approximately 5 mg/L directly from simple sugars. We envision that our approach will provide a scalable, controllable and economic route to this important class of chemicals. Copyright © 2013 International Metabolic Engineering Society. All rights reserved.

A First Step towards Variational Methods in Engineering

ERIC Educational Resources Information Center

Periago, Francisco

2003-01-01

In this paper, a didactical proposal is presented to introduce the variational methods for solving boundary value problems to engineering students. Starting from a couple of simple models arising in linear elasticity and heat diffusion, the concept of weak solution for these models is motivated and the existence, uniqueness and continuous…

A Competency Based Curriculum Guide: Ethanol Spark Ignition Engine Conversion.

ERIC Educational Resources Information Center

Blair, Brittain A.

This guide is a competency-based vocational curriculum designed to provide educators with viable ethanol (100 percent alcohol) engine conversion procedures stated in simple terms and set in a flexible educational environment. The curriculum is designed so that educators can form various combinations of instructional activities and resource…

Summer Program Introduces High School Students to Engineering.

ERIC Educational Resources Information Center

Worthy, Ward

1989-01-01

Discusses how, in two three-week sessions, the Terre Haute (Indiana) college offers selected students a hands-on approach to all aspects of engineering from design and lab work to technical writing. Describes a group project requiring students to study and experiment with simple research problems. Lists 20 project ideas. (MVL)

Inventing the Invented for STEM Understanding

ERIC Educational Resources Information Center

Stansell, Alicia; Tyler-Wood, Tandra; Stansell, Christina

2016-01-01

The reverse engineering of simple inventions that were of historic significance is now possible in a classroom by using digital models provided by places like the Smithsonian. The digital models can facilitate the mastery of students' STEM learning by utilizing digital fabrication in maker spaces to provide an opportunity for reverse engineer and…

Creating a Classroom Kaleidoscope with the World Wide Web.

ERIC Educational Resources Information Center

Quinlan, Laurie A.

1997-01-01

Discusses the elements of classroom Web presentations: planning; construction, including design tips; classroom use; and assessment. Lists 14 World Wide Web resources for K-12 teachers; Internet search tools (directories, search engines and meta-search engines); a Web glossary; and an example of HTML for a simple Web page. (PEN)

Sorption of Radionuclides to Building Materials and its Removal Using Simple Wash Solutions

EPA Pesticide Factsheets

Data corresponding to the figures in the paper.This dataset is associated with the following publication:Kaminski, M., C. Mertz, L. Ortega, and N. Kivenas. Sorption of Radionuclides to Building Materials and its Removal Using Simple Wash Solutions. Journal of Environmental Chemical Engineering. Elsevier B.V., Amsterdam, NETHERLANDS, ., (2016).

A Simple Educational Method for the Measurement of Liquid Binary Diffusivities

ERIC Educational Resources Information Center

Rice, Nicholas P.; de Beer, Martin P.; Williamson, Mark E.

2014-01-01

A simple low-cost experiment has been developed for the measurement of the binary diffusion coefficients of liquid substances. The experiment is suitable for demonstrating molecular diffusion to small or large undergraduate classes in chemistry or chemical engineering. Students use a cell phone camera in conjunction with open-source image…

Hooke's Law and the Stiffness of a Plastic Spoon

ERIC Educational Resources Information Center

Pestka, Kenneth A., II; Warren, Cori

2012-01-01

The study of elastic properties of solids is essential to both physics and engineering. Finding simple, easy-to-visualize examples to demonstrate these concepts is often difficult. In a previous article written by one of us (KAPII), a simple method for determining Youngs modulus using marshmallows was given. In this article we will illustrate…

Search without Boundaries Using Simple APIs

USGS Publications Warehouse

Tong, Qi

2009-01-01

The U.S. Geological Survey (USGS) Library, where the author serves as the digital services librarian, is increasingly challenged to make it easier for users to find information from many heterogeneous information sources. Information is scattered throughout different software applications (i.e., library catalog, federated search engine, link resolver, and vendor websites), and each specializes in one thing. How could the library integrate the functionalities of one application with another and provide a single point of entry for users to search across? To improve the user experience, the library launched an effort to integrate the federated search engine into the library's intranet website. The result is a simple search box that leverages the federated search engine's built-in application programming interfaces (APIs). In this article, the author describes how this project demonstrated the power of APIs and their potential to be used by other enterprise search portals inside or outside of the library.

10. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model No. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. To the left of the horizontal (fluted) cylinder is the water pump which moved the boiler feed water through the engine's pre-heat system (the exhaust steam heated the boiler feedwater before it was pumped on to the boiler). The steam-feed port, manual throttle valve, and fly-ball governor and pulley and to the right of the cylinder. The drive shaft with flywheel to the left and pulley to the right are seen behind the piston rod, cross-head, wrist pen, connecting rod and the slide valve and eccentric. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

7. RW Meyer Sugar Mill: 18761889. Engine and boiler house; ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. RW Meyer Sugar Mill: 1876-1889. Engine and boiler house; ca. 1881. Simple, single-cylinder, horizontal, reciprocating steam engine, model No. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Historical view, 1934, from T. T. Waterman collection, Hawaiian Sugar Planters' Association. View shows interior of engine and boiler house intact. The steam-feed pipe is still attached to throttle valve, not the case in 1978 view. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

On the dynamical vs. thermodynamical performance of a β-type Stirling engine

NASA Astrophysics Data System (ADS)

Reséndiz-Antonio, Margarita; Santillán, Moisés

2014-09-01

In this work we present a simple mathematical model for a β-type Stirling engine. Despite its simplicity, the model considers all the engine’s relevant thermodynamic and mechanical aspects. The dynamic behavior of the model equation of motion is analyzed in order to obtain the sufficient conditions for engine cycling and to study the stability of the stationary regime. The performance of the engine’s thermodynamic part is also investigated. As a matter of fact, we found that it corresponds to a Carnot engine.

''Math in a Can'': Teaching Mathematics and Engineering Design

ERIC Educational Resources Information Center

Narode, Ronald B.

2011-01-01

Using an apparently simple problem, ''Design a cylindrical can that will hold a liter of milk,'' this paper demonstrates how engineering design may facilitate the teaching of the following ideas to secondary students: linear and non-linear relationships; basic geometry of circles, rectangles, and cylinders; unit measures of area and volume;…

Synthetic Organic Electrochemistry: Calling All Engineers.

PubMed

Yan, Ming; Kawamata, Yu; Baran, Phil S

2018-04-09

Unmet potential: Electrochemistry is the most simple and basic way of altering the redox-states of organic molecules. Despite extensive studies and its demonstrated promise, it has yet to take off in mainstream synthesis. The reason is due to engineering challenges in instrument design. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Systems Engineering of Education V: Quantitative Concepts for Education Systems.

ERIC Educational Resources Information Center

Silvern, Leonard C.

The fifth (of 14) volume of the Education and Training Consultant's (ETC) series on systems engineering of education is designed for readers who have completed others in the series. It reviews arithmetic and algebraic procedures and applies these to simple education and training systems. Flowchart models of example problems are developed and…

Development and Characterization of Laser-Induced Incandescence Towards Nanoparticle (Soot) Detection

NASA Technical Reports Server (NTRS)

VanderWal, Randy L.

2000-01-01

The production of particulates, notably soot, during combustion has both positive and negative ramifications. Exhaust from diesel engines under load (for example, shifting gears), flickering candle flames and fireplaces all produce soot leaving a flame. From an efficiency standpoint, emission of soot from engines, furnaces or even a simple flickering candle flame represents a loss of useful energy. The emission of soot from diesel engines, furnaces, power generation facilities, incinerators and even simple flames poses a serious environmental problem and health risk. Yet some industries intentionally produce soot as carbon black for use in inks, copier toner, tires and as pigments. Similarly, the presence of soot within flames can act both positively and negatively. Energy transfer from a combustion process is greatly facilitated by the radiative heat transfer from soot yet radiative heat transfer also facilitates the spread of unwanted fires. To understand soot formation and develop control strategies for soot emission/formation, measurements of soot concentration in both practical devices such as engines and controlled laboratory flames are necessary. Laser-induced incandescence (LII) has been developed and characterized to address this need, as described here.

Task 6 -- Advanced turbine systems program conceptual design and product development

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-01-10

The Allison Engine Company has completed the Task 6 Conceptual Design and Analysis of Phase 2 of the Advanced Turbine System (ATS) contract. At the heart of Allison`s system is an advanced simple cycle gas turbine engine. This engine will incorporate components that ensure the program goals are met. Allison plans to commercialize the ATS demonstrator and market a family of engines incorporating this technology. This family of engines, ranging from 4.9 MW to 12 MW, will be suitable for use in all industrial engine applications, including electric power generation, mechanical drive, and marine propulsion. In the field of electricmore » power generation, the engines will be used for base load, standby, cogeneration, and distributed generation applications.« less

Overview of NASA Lewis Research Center free-piston Stirling engine technology activities applicable to space power systems

NASA Technical Reports Server (NTRS)

Slaby, Jack G.

1987-01-01

A brief overview is presented of the development and technological activities of the free-piston Stirling engine. The engine started as a small scale fractional horsepower engine which demonstrated basic engine operating principles and the advantages of being hermetically sealed, highly efficient, and simple. It eventually developed into the free piston Stirling engine driven heat pump, and then into the SP-100 Space Reactor Power Program from which came the Space Power Demonstrator Engine (SPDE). The SPDE successfully operated for over 300 hr and delivered 20 kW of PV power to an alternator plunger. The SPDE demonstrated that a dynamic power conversion system can, with proper design, be balanced; and the engine performed well with externally pumped hydrostatic gas bearings.

Large liquid rocket engine transient performance simulation system

NASA Technical Reports Server (NTRS)

Mason, J. R.; Southwick, R. D.

1989-01-01

Phase 1 of the Rocket Engine Transient Simulation (ROCETS) program consists of seven technical tasks: architecture; system requirements; component and submodel requirements; submodel implementation; component implementation; submodel testing and verification; and subsystem testing and verification. These tasks were completed. Phase 2 of ROCETS consists of two technical tasks: Technology Test Bed Engine (TTBE) model data generation; and system testing verification. During this period specific coding of the system processors was begun and the engineering representations of Phase 1 were expanded to produce a simple model of the TTBE. As the code was completed, some minor modifications to the system architecture centering on the global variable common, GLOBVAR, were necessary to increase processor efficiency. The engineering modules completed during Phase 2 are listed: INJTOO - main injector; MCHBOO - main chamber; NOZLOO - nozzle thrust calculations; PBRNOO - preburner; PIPE02 - compressible flow without inertia; PUMPOO - polytropic pump; ROTROO - rotor torque balance/speed derivative; and TURBOO - turbine. Detailed documentation of these modules is in the Appendix. In addition to the engineering modules, several submodules were also completed. These submodules include combustion properties, component performance characteristics (maps), and specific utilities. Specific coding was begun on the system configuration processor. All functions necessary for multiple module operation were completed but the SOLVER implementation is still under development. This system, the Verification Checkout Facility (VCF) allows interactive comparison of module results to store data as well as provides an intermediate checkout of the processor code. After validation using the VCF, the engineering modules and submodules were used to build a simple TTBE.

CUTE: A Concolic Unit Testing Engine for C

DTIC Science & Technology

2005-01-01

We also introduce program units of a simple C-like language (cf. [20]). We present how CUTE instruments programs and performs concolic execution. We...works for a simple C-like language shown in Figure 2. START represents the first statement of a program under test. Each statement has an optional...is a variable, c is a constant p ::= v = v | v 6= v | v < v | v ≤ v | v ≥ v | v > v Figure 2: Syntax of a simple C-like language the inputs at the

Summer Research Program - 1997 Summer Faculty Research Program Volume 6 Arnold Engineering Development Center United States Air Force Academy Air Logistics Centers

DTIC Science & Technology

1997-12-01

Fracture Analysis of the F-5, 15%-Spar Bolt DR Devendra Kumar SAALC/LD 6- 16 CUNY-City College, New York, NY A Simple, Multiversion Concurrency Control...Program, University of Dayton, Dayton, OH. [3]AFGROW, Air Force Crack Propagation Analysis Program, Version 3.82 (1997) 15-8 A SIMPLE, MULTIVERSION ...Office of Scientific Research Boiling Air Force Base, DC and San Antonio Air Logistic Center August 1997 16-1 A SIMPLE, MULTIVERSION CONCURRENCY

Two simple models of classical heat pumps.

PubMed

Marathe, Rahul; Jayannavar, A M; Dhar, Abhishek

2007-03-01

Motivated by recent studies of models of particle and heat quantum pumps, we study similar simple classical models and examine the possibility of heat pumping. Unlike many of the usual ratchet models of molecular engines, the models we study do not have particle transport. We consider a two-spin system and a coupled oscillator system which exchange heat with multiple heat reservoirs and which are acted upon by periodic forces. The simplicity of our models allows accurate numerical and exact solutions and unambiguous interpretation of results. We demonstrate that while both our models seem to be built on similar principles, one is able to function as a heat pump (or engine) while the other is not.

Speed, Acceleration, and Velocity: Level II, Unit 9, Lesson 1; Force, Mass, and Distance: Lesson 2; Types of Motion and Rest: Lesson 3; Electricity and Magnetism: Lesson 4; Electrical, Magnetic, and Gravitational Fields: Lesson 5; The Conservation and Conversion of Matter and Energy: Lesson 6; Simple Machines and Work: Lesson 7; Gas Laws: Lesson 8; Principles of Heat Engines: Lesson 9; Sound and Sound Waves: Lesson 10; Light Waves and Particles: Lesson 11; Program. A High.....

ERIC Educational Resources Information Center

Manpower Administration (DOL), Washington, DC. Job Corps.

This self-study program for high-school level contains lessons on: Speed, Acceleration, and Velocity; Force, Mass, and Distance; Types of Motion and Rest; Electricity and Magnetism; Electrical, Magnetic, and Gravitational Fields; The Conservation and Conversion of Matter and Energy; Simple Machines and Work; Gas Laws; Principles of Heat Engines;…

Capacitive sensor for engine oil deterioration measurement

NASA Astrophysics Data System (ADS)

Shinde, Harish; Bewoor, Anand

2018-04-01

A simple system or mechanism for engine Oil (lubricating oil) deterioration monitoring is a need. As engine oil is an important element in I C engines and it is exposed to various strains depending on the operating conditions. If it becomes contaminated with dirt and metal particles, it can become too thick or thin and loses its protective properties, leads to unwanted friction. In turn, to avoid an engine failure, the oil must be changed before it loses its protective properties, which may be harmful to engine which deteriorates vehicle performance. At the same time, changing the lubricant too early, cause inefficient use of already depleting resources, also unwanted impact on the environment and economic reasons. Hence, it will be always helpful to know the quality of the oil under use. With this objective, the research work had been undertaken to develop a simple capacitance sensor for quantification of the quality of oil under use. One of the investigated parameter to quantify oil degradation is Viscosity (as per standard testing procedure: DIN 51562-1). In this research work, an alternative method proposed which analyzing change in capacitance of oil, to quantify the quality of oil underuse and compared to a conventional standard method. The experimental results reported in this paper shows trend for the same. Engine oil of grade SAE 15W40 used for light-duty vehicle, vans and passenger cars is used for experimentation. Suggested method can form a base for further research to develop a cost-effective method for indicating the time to change in engine oil quality have been presented.

From Spintronics to CFD/ContractForDifferences

NASA Astrophysics Data System (ADS)

Maksoed, W. H.

2015-11-01

Involve the CFD/Computational Fluid Dynamics & HCCI/Homogeneous Charge Compression Ignition - Marcine Frackowiak, dissertation, 2009, for CFD/Contract For Differences accompanied by ``One Man's Crusade to Exonerate Hydrogen for Hindenburg Disaster'' of Addison BAIN, APS News, v. 9, n.7 (July 2000) concludes ``ignition of the blaze'' are responsible to those May, 1937 Accidents. Spintronics their selves include active control & manipulation of spin degree of freedom ever denotes: the nano-obelisk of scanning electron microscopy of galliumnitride/GaN nanostructures-Yong-Hon Cho et al.:``Novel Photonic Device using core-shell nanostructures'', SPIE-newsroom,10.1117/2.1201503.005864. Herewith commercial activated carbon/C can be imaged directly using abberation-corrected transmission electron microscopy[PJF Harris et al.: ``Imaging the Atomic Structures of activated C'', J. Phys. Condens. Matt, 20 (2008) in fig b & c- images networks of hexagonal rings can be clearly be seen depicts equal etchings of 340 px Akhenaten, Nefertiti & their childrens. Incredible acknowledgments to Minister of Education & Culture RI 1998-1999 HE. Mr. Prof. Ir. WIRANTO ARISMUNANDAR, MSME.

Liquid-Phase Laser Induced Forward Transfer for Complex Organic Inks and Tissue Engineering.

PubMed

Nguyen, Alexander K; Narayan, Roger J

2017-01-01

Laser induced forward transfer (LIFT) acts as a novel alternative to incumbent plotting techniques such as inkjet printing due to its ability to precisely deposit and position picoliter-sized droplets while being gentle enough to preserve sensitive structures within the ink. Materials as simple as screen printing ink to complex eukaryotic cells have been printed with applications spanning from microelectronics to tissue engineering. Biotechnology can benefit from this technique due to the efficient use of low volumes of reagent and the compatibility with a wide range of rheological properties. In addition, LIFT can be performed in a simple lab environment, not requiring vacuum or other extreme conditions. Although the basic apparatus is simple, many strategies exist to optimize the performance considering the ink and the desired pattern. The basic mechanism is similar between studies so the large number of variants can be summarized into a couple of categories and reported on with respect to their specific applications. In particular, precise and gentle deposition of complex molecules and eukaryotic cells represent the unique abilities of this technology. LIFT has demonstrated not only marked improvements in the quality of sensors and related medical devices over those manufactured with incumbent technologies but also great applicability in tissue engineering due to the high viability of printed cells.

Engineering model for ultrafast laser microprocessing

NASA Astrophysics Data System (ADS)

Audouard, E.; Mottay, E.

2016-03-01

Ultrafast laser micro-machining relies on complex laser-matter interaction processes, leading to a virtually athermal laser ablation. The development of industrial ultrafast laser applications benefits from a better understanding of these processes. To this end, a number of sophisticated scientific models have been developed, providing valuable insights in the physics of the interaction. Yet, from an engineering point of view, they are often difficult to use, and require a number of adjustable parameters. We present a simple engineering model for ultrafast laser processing, applied in various real life applications: percussion drilling, line engraving, and non normal incidence trepanning. The model requires only two global parameters. Analytical results are derived for single pulse percussion drilling or simple pass engraving. Simple assumptions allow to predict the effect of non normal incident beams to obtain key parameters for trepanning drilling. The model is compared to experimental data on stainless steel with a wide range of laser characteristics (time duration, repetition rate, pulse energy) and machining conditions (sample or beam speed). Ablation depth and volume ablation rate are modeled for pulse durations from 100 fs to 1 ps. Trepanning time of 5.4 s with a conicity of 0.15° is obtained for a hole of 900 μm depth and 100 μm diameter.

Study on a Simple Method for Controlling the Engine Output Power of Hybrid Powered Railway Vehicles with Electric Double Layer Capacitors

NASA Astrophysics Data System (ADS)

Okano, Shota; Shibuya, Hiroyuki; Kondo, Keiichiro

This paper presents a simple and energy-saving method for controlling hybrid powered railway vehicles that run on rural non-electrified railway lines and have diesel engine and electrical double layer capacitors (EDLCs). The aim this study is to reduce both the fuel consumption and the capacitance of EDLCs. A basic idea proposed in this paper is that EDLCs supply and absorb the kinetic energy of the vehicle and the engine output compensates supply the energy loss with the vehicle running. Thus, the energy loss is not taken into consideration while expressing the EDLC voltage reference (equation 1); energy loss is considered when the engine is in operating mode. The proposed method is examined by performing numerical simulations for various values of engine operation time, load, and grade section. The results of this study reveal the relationship between the capacitance of the EDLCs and the fuel consumption. Using this proposed control methods, excessive charging of EDLCs can be avoided. The results of this study are expected to expedite the development of energy-saving railway vehicles for the non-electrified lines. Finally, the results of this study increase the possibility of developing hybrid powered railway vehicles.

Critical Reading of the Web

ERIC Educational Resources Information Center

Griffin, Teresa; Cohen, Deb

2012-01-01

The ubiquity and familiarity of the world wide web means that students regularly turn to it as a source of information. In doing so, they "are said to rely heavily on simple search engines, such as Google to find what they want." Researchers have also investigated how students use search engines, concluding that "the young web users tended to…

Aspects on Teaching/Learning with Object Oriented Programming for Entry Level Courses of Engineering.

ERIC Educational Resources Information Center

de Oliveira, Clara Amelia; Conte, Marcos Fernando; Riso, Bernardo Goncalves

This work presents a proposal for Teaching/Learning, on Object Oriented Programming for Entry Level Courses of Engineering and Computer Science, on University. The philosophy of Object Oriented Programming comes as a new pattern of solution for problems, where flexibility and reusability appears over the simple data structure and sequential…

Introducing High School Students to Chemical Engineering Kinetics with a Simple Experiment-Based Smartphone Education Application

ERIC Educational Resources Information Center

Stanley, Simone; Ymele-Leki, Patrick

2017-01-01

A community outreach project was integrated in a District of Columbia public schools summer internship program for students from underrepresented minorities in STEM. The project introduced these students to fundamental engineering principles by leveraging a smartphone application (App) so readily accessible and attractive to them that it boosted…

Impact of an Engineering Design-Based Curriculum Compared to an Inquiry-Based Curriculum on Fifth Graders' Content Learning of Simple Machines

ERIC Educational Resources Information Center

Marulcu, Ismail; Barnett, Michael

2016-01-01

Background: Elementary Science Education is struggling with multiple challenges. National and State test results confirm the need for deeper understanding in elementary science education. Moreover, national policy statements and researchers call for increased exposure to engineering and technology in elementary science education. The basic…

Reflecting on Classroom Practice: Spatial Reasoning and Simple Coding

ERIC Educational Resources Information Center

King, Alessandra

2015-01-01

Spatial reasoning--the ability to visualise and play with shapes in one's mind--is essential in many fields, and crucial in any Science, Technology, Engineering, Mathematics [STEM] discipline. It is, for example, the ability that the engineer needs to build bridges; the chemist to see the three-dimensional structure of a molecule; the architect to…

Micro- and Macroscale Ideas of Current among Upper-Division Electrical Engineering Students

ERIC Educational Resources Information Center

Adam, Gina C.; Harlow, Danielle B.; Lord, Susan M.; Kautz, Christian H.

2017-01-01

The concept of electric current is fundamental in the study of electrical engineering (EE). Students are often exposed to this concept in their daily lives and early in middle school education. Lower-division university courses are usually limited to the study of passive electronic devices and simple electric circuits. Semiconductor physics is an…

Integrated two-cylinder liquid piston Stirling engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Ning; Rickard, Robert; Pluckter, Kevin

2014-10-06

Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harnessmore » useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.« less

Electrochemical energy engineering: a new frontier of chemical engineering innovation.

PubMed

Gu, Shuang; Xu, Bingjun; Yan, Yushan

2014-01-01

One of the grand challenges facing humanity today is a safe, clean, and sustainable energy system where combustion no longer dominates. This review proposes that electrochemical energy conversion could set the foundation for such an energy system. It further suggests that a simple switch from an acid to a base membrane coupled with innovative cell designs may lead to a new era of affordable electrochemical devices, including fuel cells, electrolyzers, solar hydrogen generators, and redox flow batteries, for which recent progress is discussed using the authors' work as examples. It also notes that electrochemical energy engineering will likely become a vibrant subdiscipline of chemical engineering and a fertile ground for chemical engineering innovation. To realize this vision, it is necessary to incorporate fundamental electrochemistry and electrochemical engineering principles into the chemical engineering curriculum.

System analysis of a piston steam engine employing the uniflow principle, a study in optimized performance

NASA Technical Reports Server (NTRS)

Peoples, J. A.

1975-01-01

Results are reported which were obtained from a mathematical model of a generalized piston steam engine configuration employing the uniflow principal. The model accounted for the effects of clearance volume, compression work, and release volume. A simple solution is presented which characterizes optimum performance of the steam engine, based on miles per gallon. Development of the mathematical model is presented. The relationship between efficiency and miles per gallon is developed. An approach to steam car analysis and design is presented which has purpose rather than lucky hopefulness. A practical engine design is proposed which correlates to the definition of the type engine used. This engine integrates several system components into the engine structure. All conclusions relate to the classical Rankine Cycle.

Integrated two-cylinder liquid piston Stirling engine

NASA Astrophysics Data System (ADS)

Yang, Ning; Rickard, Robert; Pluckter, Kevin; Sulchek, Todd

2014-10-01

Heat engines utilizing the Stirling cycle may run on low temperature differentials with the capacity to function at high efficiency due to their near-reversible operation. However, current approaches to building Stirling engines are laborious and costly. Typically the components are assembled by hand and additional components require a corresponding increase in manufacturing complexity, akin to electronics before the integrated circuit. We present a simple and integrated approach to fabricating Stirling engines with precisely designed cylinders. We utilize computer aided design and one-step, planar machining to form all components of the engine. The engine utilizes liquid pistons and displacers to harness useful work from heat absorption and rejection. As a proof of principle of the integrated design, a two-cylinder engine is produced and characterized and liquid pumping is demonstrated.

Response of a small-turboshaft-engine compression system to inlet temperature distortion

NASA Technical Reports Server (NTRS)

Biesiadny, T. J.; Klann, G. A.; Little, J. K.

1984-01-01

An experimental investigation was conducted into the response of a small-turboshaft-engine compression system to steady-state and transient inlet temperature distortions. Transient temperature ramps range from less than 100 K/sec to above 610 K/sec and generated instantaneous temperatures to 420 K above ambient. Steady-state temperature distortion levels were limited by the engine hardware temperature list. Simple analysis of the steady-state distortion data indicated that a particle separator at the engine inlet permitted higher levels of temperature distortion before onset of compressor surge than would be expected without the separator.

Recent advances and versatility of MAGE towards industrial applications.

PubMed

Singh, Vijai; Braddick, Darren

2015-12-01

The genome engineering toolkit has expanded significantly in recent years, allowing us to study the functions of genes in cellular networks and assist in over-production of proteins, drugs, chemicals and biofuels. Multiplex automated genome engineering (MAGE) has been recently developed and gained more scientific interest towards strain engineering. MAGE is a simple, rapid and efficient tool for manipulating genes simultaneously in multiple loci, assigning genetic codes and integrating non-natural amino acids. MAGE can be further expanded towards the engineering of fast, robust and over-producing strains for chemicals, drugs and biofuels at industrial scales.

Combining engineered cell-sensors with multi-agent systems to realize smart environment

NASA Astrophysics Data System (ADS)

Chen, Mei

2013-03-01

The connection of everything in a sensory and an intelligent way is a pursuit in smart environment. This paper introduces the engineered cell-sensors into the multi-agent systems to realize the smart environment. The seamless interface with the natural environment and strong information-processing ability of cell with the achievements of synthetic biology make the construction of engineered cell-sensors possible. However, the engineered cell-sensors are only simple-functional and unreliable computational entities. Therefore how to combine engineered cell-sensors with digital device is a key problem in order to realize the smart environment. We give the abstract structure and interaction modes of the engineered cell-sensors in order to introduce engineered cell-sensors into multi-agent systems. We believe that the introduction of engineered cell-sensors will push forward the development of the smart environment.

A hybrid rocket engine design for simple low cost sounding rocket use

NASA Astrophysics Data System (ADS)

Grubelich, Mark; Rowland, John; Reese, Larry

1993-06-01

Preliminary test results on a nitrous oxide/HTPB hybrid rocket engine suitable for powering a small sounding rocket to altitudes of 50-100 K/ft are presented. It is concluded that the advantage of the N2O hybrid engine over conventional solid propellant rocket motors is the ability to obtain long burn times with core burning geometries due to the low regression rate of the fuel. Long burn times make it possible to reduce terminal velocity to minimize air drag losses.

Keeping Dublin Core Simple: Cross-Domain Discovery or Resource Description?; First Steps in an Information Commerce Economy: Digital Rights Management in the Emerging E-Book Environment; Interoperability: Digital Rights Management and the Emerging EBook Environment; Searching the Deep Web: Direct Query Engine Applications at the Department of Energy.

ERIC Educational Resources Information Center

Lagoze, Carl; Neylon, Eamonn; Mooney, Stephen; Warnick, Walter L.; Scott, R. L.; Spence, Karen J.; Johnson, Lorrie A.; Allen, Valerie S.; Lederman, Abe

2001-01-01

Includes four articles that discuss Dublin Core metadata, digital rights management and electronic books, including interoperability; and directed query engines, a type of search engine designed to access resources on the deep Web that is being used at the Department of Energy. (LRW)

SHERLOCK: Simple Human Experiments Regarding Locally Observed Collective Knowledge

DTIC Science & Technology

2015-12-01

ARL-RP-0560 ● DEC 2015 US Army Research Laboratory SHERLOCK: Simple Human Experiments Regarding Locally Observed Collective...report when it is no longer needed. Do not return it to the originator. ARL-RP-0560 ● DEC 2015 US Army Research Laboratory SHERLOCK... Research and Engineering Directorate, ARL Reprinted from the International Technology Alliance Collaboration System [accessed 2015 Dec 2]. https

Teach Deflection Concepts with Hacksaw Blades and Rubber Bands

ERIC Educational Resources Information Center

Roman, Harry T.

2013-01-01

Technology and engineering educators can use a simple hacksaw blade to help students learn about deflection, as that which occurs in a beam. Here the beam is fixed at one end and allowed to deflect in a manner that is easy to see and measure--the hacksaw blade represents a cantilever, an overhanging structure. This simple and very inexpensive…

Simple explanations and reasoning: From philosophy of science to expert systems

NASA Technical Reports Server (NTRS)

Rochowiak, Daniel

1988-01-01

A preliminary prototype of a simple explanation system was constructed. Although the system, based on the idea of storytelling, did not incorporate all of the principles of simple explanation, it did demonstrate the potential of the approach. The system incorporated a hypertext system, an inference engine, and facilities for constructing contrast type explanations. The continued development of such a system should prove to be valuable. By extending the resources of the expert system paradigm, the knowledge engineer is not forced to learn a new set of skills, and the domain knowledge already acquired by him is not lost. Further, both the beginning user and the more advanced user can be accommodated. For the beginning user, corrective explanations and ES explanations provide facilities for more clearly understanding the way in which the system is functioning. For the more advanced user, the instance and state explanations allow him to focus on the issues at hand. The simple model of explanation attempts to exploit and show how the why and how facilities of the expert system paradigm can be extended by attending to the pragmatics of explanation and adding texture to the ordinary pattern of reasoning in a rule based system.

Experimental temperature analysis of simple & hybrid earth air tunnel heat exchanger in series connection at Bikaner Rajasthan India

NASA Astrophysics Data System (ADS)

Jakhar, O. P.; Sharma, Chandra Shekhar; Kukana, Rajendra

2018-05-01

The Earth Air Tunnel Heat Exchanger System is a passive air-conditioning system which has no side effect on earth climate and produces better cooling effect and heating effect comfortable to human body. It produces heating effect in winter and cooling effect in summer with the minimum power consumption of energy as compare to other air-conditioning devices. In this research paper Temperature Analysis was done on the two systems of Earth Air Tunnel Heat Exchanger experimentally for summer cooling purpose. Both the system was installed at Mechanical Engineering Department Government Engineering College Bikaner Rajasthan India. Experimental results concludes that the Average Air Temperature Difference was found as 11.00° C and 16.27° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively. The Maximum Air Temperature Difference was found as 18.10° C and 23.70° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively. The Minimum Air Temperature Difference was found as 5.20° C and 11.70° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively.

Robust Rocket Engine Concept

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.

1995-01-01

The potential for a revolutionary step in the durability of reusable rocket engines is made possible by the combination of several emerging technologies. The recent creation and analytical demonstration of life extending (or damage mitigating) control technology enables rapid rocket engine transients with minimum fatigue and creep damage. This technology has been further enhanced by the formulation of very simple but conservative continuum damage models. These new ideas when combined with recent advances in multidisciplinary optimization provide the potential for a large (revolutionary) step in reusable rocket engine durability. This concept has been named the robust rocket engine concept (RREC) and is the basic contribution of this paper. The concept also includes consideration of design innovations to minimize critical point damage.

Make Your Workflows Smarter

NASA Technical Reports Server (NTRS)

Jones, Corey; Kapatos, Dennis; Skradski, Cory

2012-01-01

Do you have workflows with many manual tasks that slow down your business? Or, do you scale back workflows because there are simply too many manual tasks? Basic workflow robots can automate some common tasks, but not everything. This presentation will show how advanced robots called "expression robots" can be set up to perform everything from simple tasks such as: moving, creating folders, renaming, changing or creating an attribute, and revising, to more complex tasks like: creating a pdf, or even launching a session of Creo Parametric and performing a specific modeling task. Expression robots are able to utilize the Java API and Info*Engine to do almost anything you can imagine! Best of all, these tools are supported by PTC and will work with later releases of Windchill. Limited knowledge of Java, Info*Engine, and XML are required. The attendee will learn what task expression robots are capable of performing. The attendee will learn what is involved in setting up an expression robot. The attendee will gain a basic understanding of simple Info*Engine tasks

Protein consensus-based surface engineering (ProCoS): a computer-assisted method for directed protein evolution.

PubMed

Shivange, Amol V; Hoeffken, Hans Wolfgang; Haefner, Stefan; Schwaneberg, Ulrich

2016-12-01

Protein consensus-based surface engineering (ProCoS) is a simple and efficient method for directed protein evolution combining computational analysis and molecular biology tools to engineer protein surfaces. ProCoS is based on the hypothesis that conserved residues originated from a common ancestor and that these residues are crucial for the function of a protein, whereas highly variable regions (situated on the surface of a protein) can be targeted for surface engineering to maximize performance. ProCoS comprises four main steps: ( i ) identification of conserved and highly variable regions; ( ii ) protein sequence design by substituting residues in the highly variable regions, and gene synthesis; ( iii ) in vitro DNA recombination of synthetic genes; and ( iv ) screening for active variants. ProCoS is a simple method for surface mutagenesis in which multiple sequence alignment is used for selection of surface residues based on a structural model. To demonstrate the technique's utility for directed evolution, the surface of a phytase enzyme from Yersinia mollaretii (Ymphytase) was subjected to ProCoS. Screening just 1050 clones from ProCoS engineering-guided mutant libraries yielded an enzyme with 34 amino acid substitutions. The surface-engineered Ymphytase exhibited 3.8-fold higher pH stability (at pH 2.8 for 3 h) and retained 40% of the enzyme's specific activity (400 U/mg) compared with the wild-type Ymphytase. The pH stability might be attributed to a significantly increased (20 percentage points; from 9% to 29%) number of negatively charged amino acids on the surface of the engineered phytase.

Biodiesel From waste cooking oil for heating, lighting, or running diesel engines

Treesearch

Rico O. Cruz

2009-01-01

Biodiesel and its byproducts and blends can be used as alternative fuel in diesel engines and for heating, cooking, and lighting. A simple process of biodiesel production can utilize waste cooking oil as the main feedstock to the transesterification and cruzesterification processes. I currently make my own biodiesel for applications related to my nursery and greenhouse...

An Arduino Investigation of Simple Harmonic Motion

ERIC Educational Resources Information Center

Galeriu, Calin; Edwards, Scott; Esper, Geoffrey

2014-01-01

We cannot hope for a new generation of scientists and engineers if we don't let our young students take ownership of their scientific and engineering explorations, if we don't let them enjoy the hands-on cycle of design and production, and if we don't let them implant their creativity into a technologically friendly environment.…

Active Learning Session Based on Didactical Engineering Framework for Conceptual Change in Students' Equilibrium and Stability Understanding

ERIC Educational Resources Information Center

Canu, Michael; Duque, Mauricio; de Hosson, Cécile

2017-01-01

Engineering students on control courses lack a deep understanding of equilibrium and stability that are crucial concepts in this discipline. Several studies have shown that students find it difficult to understand simple familiar or academic static equilibrium cases as well as dynamic ones from mechanics even if they know the discipline's criteria…

Implementing quantum logic gates with gradient ascent pulse engineering: principles and practicalities.

PubMed

Rowland, Benjamin; Jones, Jonathan A

2012-10-13

We briefly describe the use of gradient ascent pulse engineering (GRAPE) pulses to implement quantum logic gates in nuclear magnetic resonance quantum computers, and discuss a range of simple extensions to the core technique. We then consider a range of difficulties that can arise in practical implementations of GRAPE sequences, reflecting non-idealities in the experimental systems used.

The multi-queue model applied to random access protocol

NASA Astrophysics Data System (ADS)

Fan, Xinlong

2013-03-01

The connection of everything in a sensory and an intelligent way is a pursuit in smart environment. This paper introduces the engineered cell-sensors into the multi-agent systems to realize the smart environment. The seamless interface with the natural environment and strong information-processing ability of cell with the achievements of synthetic biology make the construction of engineered cell-sensors possible. However, the engineered cell-sensors are only simple-functional and unreliable computational entities. Therefore how to combine engineered cell-sensors with digital device is a key problem in order to realize the smart environment. We give the abstract structure and interaction modes of the engineered cell-sensors in order to introduce engineered cell-sensors into multi-agent systems. We believe that the introduction of engineered cell-sensors will push forward the development of the smart environment.

Stirling Laboratory Research Engine: Preprototype configuration report

NASA Technical Reports Server (NTRS)

Hoehn, F. W.

1982-01-01

The concept of a simple Stirling research engine that could be used by industrial, university, and government laboratories was studied. The conceptual and final designs, hardware fabrication and the experimental validation of a preprototype stirling laboratory research engine (SLRE) were completed. Also completed was a task to identify the potential markets for research engines of this type. An analytical effort was conducted to provide a stirling cycle computer model. The versatile engine is a horizontally opposed, two piston, single acting stirling engine with a split crankshaft drive mechanism; special instrumentation is installed at all component interfaces. Results of a thermodynamic energy balance for the system are reported. Also included are the engine performance results obtained over a range of speeds, working pressures, phase angles and gas temperatures. The potential for a stirling research engine to support the laboratory requirements of educators and researchers was demonstrated.

Heat-transfer processes in air-cooled engine cylinders

NASA Technical Reports Server (NTRS)

Pinkel, Benjamin

1938-01-01

From a consideration of heat-transfer theory, semi-empirical expressions are set up for the transfer of heat from the combustion gases to the cylinder of an air-cooled engine and from the cylinder to the cooling air. Simple equations for the average head and barrel temperatures as functions of the important engine and cooling variables are obtained from these expressions. The expressions involve a few empirical constants, which may be readily determined from engine tests. Numerical values for these constants were obtained from single-cylinder engine tests for cylinders of the Pratt & Whitney 1535 and 1340-h engines. The equations provide a means of calculating the effect of the various engine and cooling variables on the cylinder temperatures and also of correlating the results of engine cooling tests. An example is given of the application of the equations to the correlation of cooling-test data obtained in flight.

Design of a Hybrid Propulsion System for Orbit Raising Applications

NASA Astrophysics Data System (ADS)

Boman, N.; Ford, M.

2004-10-01

A trade off between conventional liquid apogee engines used for orbit raising applications and hybrid rocket engines (HRE) has been performed using a case study approach. Current requirements for lower cost and enhanced safety places hybrid propulsion systems in the spotlight. For evaluating and design of a hybrid rocket engine a parametric engineering code is developed, based on the combustion chamber characteristics of selected propellants. A single port cylindrical section of fuel grain is considered. Polyethylene (PE) and hydroxyl-terminated polybutadiene (HTPB) represents the fuels investigated. The engine design is optimized to minimize the propulsion system volume and mass, while keeping the system as simple as possible. It is found that the fuel grain L/D ratio boundary condition has a major impact on the overall hybrid rocket engine design.

A linear acoustic model for intake wave dynamics in IC engines

NASA Astrophysics Data System (ADS)

Harrison, M. F.; Stanev, P. T.

2004-01-01

In this paper, a linear acoustic model is described that has proven useful in obtaining a better understanding of the nature of acoustic wave dynamics in the intake system of an internal combustion (IC) engine. The model described has been developed alongside a set of measurements made on a Ricardo E6 single cylinder research engine. The simplified linear acoustic model reported here produces a calculation of the pressure time-history in the port of an IC engine that agrees fairly well with measured data obtained on the engine fitted with a simple intake system. The model has proved useful in identifying the role of pipe resonance in the intake process and has led to the development of a simple hypothesis to explain the structure of the intake pressure time history: the early stages of the intake process are governed by the instantaneous values of the piston velocity and the open area under the valve. Thereafter, resonant wave action dominates the process. The depth of the early depression caused by the moving piston governs the intensity of the wave action that follows. A pressure ratio across the valve that is favourable to inflow is maintained and maximized when the open period of the valve is such to allow at least, but no more than, one complete oscillation of the pressure at its resonant frequency to occur while the valve is open.

Matrix Perturbation Techniques in Structural Dynamics

NASA Technical Reports Server (NTRS)

Caughey, T. K.

1973-01-01

Matrix perturbation are developed techniques which can be used in the dynamical analysis of structures where the range of numerical values in the matrices extreme or where the nature of the damping matrix requires that complex valued eigenvalues and eigenvectors be used. The techniques can be advantageously used in a variety of fields such as earthquake engineering, ocean engineering, aerospace engineering and other fields concerned with the dynamical analysis of large complex structures or systems of second order differential equations. A number of simple examples are included to illustrate the techniques.

Combustion engine for solid and liquid fuels

NASA Technical Reports Server (NTRS)

Pabst, W.

1986-01-01

A combustion engine having no piston, a single cylinder, and a dual-action, that is applicable for solid and liquid fuels and propellants, and that functions according to the principle of annealing point ignition is presented. The invention uses environmentally benign amounts of fuel and propellants to produce gas and steam pressure, and to use a simple assembly with the lowest possible consumption and constant readiness for mixing and burning. The advantage over conventional combustion engines lies in lower consumption of high quality igniting fluid in the most cost effective manner.

Diverse Class 2 CRISPR-Cas Effector Proteins for Genome Engineering Applications.

PubMed

Pyzocha, Neena K; Chen, Sidi

2018-02-16

CRISPR-Cas genome editing technologies have revolutionized modern molecular biology by making targeted DNA edits simple and scalable. These technologies are developed by domesticating naturally occurring microbial adaptive immune systems that display wide diversity of functionality for targeted nucleic acid cleavage. Several CRISPR-Cas single effector enzymes have been characterized and engineered for use in mammalian cells. The unique properties of the single effector enzymes can make a critical difference in experimental use or targeting specificity. This review describes known single effector enzymes and discusses their use in genome engineering applications.

Comparison of two total energy systems for a diesel power generation plant. [deep space network

NASA Technical Reports Server (NTRS)

Chai, V. W.

1979-01-01

The capabilities and limitations, as well as the associated costs for two total energy systems for a diesel power generation plant are compared. Both systems utilize waste heat from engine cooling water and waste heat from exhaust gases. Pressurized water heat recovery system is simple in nature and requires no engine modifications, but operates at lower temperature ranges. On the other hand, a two-phase ebullient system operates the engine at constant temperature, provides higher temperature water or steam to the load, but is more expensive.

The design of propeller blade roots

NASA Technical Reports Server (NTRS)

Cordes, G

1942-01-01

Predicated on the assumption of certain normal conditions for engine and propeller, simple expressions for the static and dynamic stresses of propeller blade roots are evolved. They, in combination with the fatigue strength diagram of the employed material, afford for each engine power one certain operating point by which the state of stress serving as a basis for the design of the root is defined. Different stress cases must be analyzed, depending on the vibration tendency of engine and use of propeller. The solution affords an insight into the possible introduction of different size classes of propeller.

Distributed Control Architecture for Gas Turbine Engine. Chapter 4

NASA Technical Reports Server (NTRS)

Culley, Dennis; Garg, Sanjay

2009-01-01

The transformation of engine control systems from centralized to distributed architecture is both necessary and enabling for future aeropropulsion applications. The continued growth of adaptive control applications and the trend to smaller, light weight cores is a counter influence on the weight and volume of control system hardware. A distributed engine control system using high temperature electronics and open systems communications will reverse the growing trend of control system weight ratio to total engine weight and also be a major factor in decreasing overall cost of ownership for aeropropulsion systems. The implementation of distributed engine control is not without significant challenges. There are the needs for high temperature electronics, development of simple, robust communications, and power supply for the on-board electronics.

Proceedings, Seminar on Probabilistic Methods in Geotechnical Engineering

NASA Astrophysics Data System (ADS)

Hynes-Griffin, M. E.; Buege, L. L.

1983-09-01

Contents: Applications of Probabilistic Methods in Geotechnical Engineering; Probabilistic Seismic and Geotechnical Evaluation at a Dam Site; Probabilistic Slope Stability Methodology; Probability of Liquefaction in a 3-D Soil Deposit; Probabilistic Design of Flood Levees; Probabilistic and Statistical Methods for Determining Rock Mass Deformability Beneath Foundations: An Overview; Simple Statistical Methodology for Evaluating Rock Mechanics Exploration Data; New Developments in Statistical Techniques for Analyzing Rock Slope Stability.

Collagen as potential cell scaffolds for tissue engineering.

PubMed

Annuar, N; Spier, R E

2004-05-01

Selections of collagen available commercially were tested for their biocompatibility as scaffold to promote cell growth in vitro via simple collagen fast test and cultivation of mammalian cells on the selected type of collagen. It was found that collagen type C9791 promotes the highest degree of aggregation as well as cells growth. This preliminary study also indicated potential use of collagen as scaffold in engineered tissue.

Curating the Web: Building a Google Custom Search Engine for the Arts

ERIC Educational Resources Information Center

Hennesy, Cody; Bowman, John

2008-01-01

Google's first foray onto the web made search simple and results relevant. With its Co-op platform, Google has taken another step toward dramatically increasing the relevancy of search results, further adapting the World Wide Web to local needs. Google Custom Search Engine, a tool on the Co-op platform, puts one in control of his or her own search…

A Robust Damage Reporting Strategy for Polymeric Materials Enabled by Aggregation Induced Emission

DTIC Science & Technology

2016-08-17

and Technology, ‡Department of Chemistry, ∥Department of Materials Science and Engineering, ⊥Department of Mechanical Science and Engineering, and...enabled by aggregation-induced emission (AIE). This simple, yet powerful system relies on a single active component, and the general mechanism ...delivers outstanding performance in a wide variety of materials with diverse chemical and mechanical properties. Small (micrometer) scale damage in

40 CFR 98.30 - Definition of the source category.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., boilers, simple and combined-cycle combustion turbines, engines, incinerators, and process heaters. (b... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING General Stationary Fuel Combustion Sources § 98.30 Definition...

Education and research in fluid dynamics

NASA Astrophysics Data System (ADS)

López González-Nieto, P.; Redondo, J. M.; Cano, J. L.

2009-04-01

Fluid dynamics constitutes an essential subject for engineering, since auronautic engineers (airship flights in PBL, flight processes), industrial engineers (fluid transportation), naval engineers (ship/vessel building) up to agricultural engineers (influence of the weather conditions on crops/farming). All the above-mentioned examples possess a high social and economic impact on mankind. Therefore, the fluid dynamics education of engineers is very important, and, at the same time, this subject gives us an interesting methodology based on a cycle relation among theory, experiments and numerical simulation. The study of turbulent plumes -a very important convective flow- is a good example because their theoretical governing equations are simple; it is possible to make experimental plumes in an aesy way and to carry out the corresponding numerical simulatons to verify experimental and theoretical results. Moreover, it is possible to get all these aims in the educational system (engineering schools or institutions) using a basic laboratory and the "Modellus" software.

Engine Evaluation of Advanced Technology Control Components

DTIC Science & Technology

1976-08-01

producer turbine rotor blades. This is a very desirable control feature, because protecting turbine blades from overtemperature is particularly...centrifugal boost stage operating back to back on a common drive shaft that is direct driven through the alter- nator rotor shaft. The main stage is an...computation makes this simple dynamic pumping machine possible. The pen- alty of this simple design is lower overall efficiency as com- pared to a

What Do We Really Need? Visions of an Ideal Human-Machine Interface for NOTES Mechatronic Support Systems From the View of Surgeons, Gastroenterologists, and Medical Engineers.

PubMed

Kranzfelder, Michael; Schneider, Armin; Fiolka, Adam; Koller, Sebastian; Wilhelm, Dirk; Reiser, Silvano; Meining, Alexander; Feussner, Hubertus

2015-08-01

To investigate why natural orifice translumenal endoscopic surgery (NOTES) has not yet become widely accepted and to prove whether the main reason is still the lack of appropriate platforms due to the deficiency of applicable interfaces. To assess expectations of a suitable interface design, we performed a survey on human-machine interfaces for NOTES mechatronic support systems among surgeons, gastroenterologists, and medical engineers. Of 120 distributed questionnaires, each consisting of 14 distinct questions, 100 (83%) were eligible for analysis. A mechatronic platform for NOTES was considered "important" by 71% of surgeons, 83% of gastroenterologist,s and 56% of medical engineers. "Intuitivity" and "simple to use" were the most favored aspects (33% to 51%). Haptic feedback was considered "important" by 70% of participants. In all, 53% of surgeons, 50% of gastroenterologists, and 33% of medical engineers already had experience with NOTES platforms or other surgical robots; however, current interfaces only met expectations in just more than 50%. Whereas surgeons did not favor a certain working posture, gastroenterologists and medical engineers preferred a sitting position. Three-dimensional visualization was generally considered "nice to have" (67% to 72%); however, for 26% of surgeons, 17% of gastroenterologists, and 7% of medical engineers it did not matter (P = 0.018). Requests and expectations of human-machine interfaces for NOTES seem to be generally similar for surgeons, gastroenterologist, and medical engineers. Consensus exists on the importance of developing interfaces that should be both intuitive and simple to use, are similar to preexisting familiar instruments, and exceed current available systems. © The Author(s) 2014.

Sulfanilic acid-modified chitosan mini-spheres and their application for lysozyme purification from egg white.

PubMed

Hirsch, Daniela B; Baieli, María F; Urtasun, Nicolás; Lázaro-Martínez, Juan M; Glisoni, Romina J; Miranda, María V; Cascone, Osvaldo; Wolman, Federico J

2018-03-01

A cation exchange matrix with zwitterionic and multimodal properties was synthesized by a simple reaction sequence coupling sulfanilic acid to a chitosan based support. The novel chromatographic matrix was physico-chemically characterized by ss-NMR and ζ potential, and its chromatographic performance was evaluated for lysozyme purification from diluted egg white. The maximum adsorption capacity, calculated according to Langmuir adsorption isotherm, was 50.07 ± 1.47 mg g -1 while the dissociation constant was 0.074 ± 0.012 mg mL -1 . The process for lysozyme purification from egg white was optimized, with 81.9% yield and a purity degree of 86.5%, according to RP-HPLC analysis. This work shows novel possible applications of chitosan based materials. The simple synthesis reactions combined with the simple mode of use of the chitosan matrix represents a novel method to purify proteins from raw starting materials. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:387-396, 2018. © 2017 American Institute of Chemical Engineers.

Application of simple biomechanical and biochemical tests to heart valve leaflets: implications for heart valve characterization and tissue engineering.

PubMed

Huang, Hsiao-Ying S; Balhouse, Brittany N; Huang, Siyao

2012-11-01

A simple biomechanical test with real-time displacement and strain mapping is reported, which provides displacement vectors and principal strain directions during the mechanical characterization of heart valve tissues. The maps reported in the current study allow us to quickly identify the approximate strain imposed on a location in the samples. The biomechanical results show that the aortic valves exhibit stronger anisotropic mechanical behavior than that of the pulmonary valves before 18% strain equibiaxial stretching. In contrast, the pulmonary valves exhibit stronger anisotropic mechanical behavior than aortic valves beyond 28% strain equibiaxial stretching. Simple biochemical tests are also conducted. Collagens are extracted at different time points (24, 48, 72, and 120 h) at different locations in the samples. The results show that extraction time plays an important role in determining collagen concentration, in which a minimum of 72 h of extraction is required to obtain saturated collagen concentration. This work provides an easy approach for quantifying biomechanical and biochemical properties of semilunar heart valve tissues, and potentially facilitates the development of tissue engineered heart valves.

Designing, engineering, and testing wood structures

NASA Technical Reports Server (NTRS)

Gorman, Thomas M.

1992-01-01

The objective of this paper is to introduce basic structural engineering concepts in a clear, simple manner while actively involving students. This project emphasizes the fact that a good design uses materials efficiently. The test structure in this experiment can easily be built and has various design options. Even when the structure is loaded to collapsing, only one or two pieces usually break, leaving the remaining pieces intact and reusable.

SE Capstone Project: Building Systems Engineering Education and Workforce Capacity

DTIC Science & Technology

2012-04-01

This project developed a system to improve fuel efficiency by means of regenerative braking . The team designed a simple system that allows "bolt-on...air traffic control, social networking, credit/debit cards, and anti-lock brakes are only a few functions enabled by complex systems of systems . We...Building Systems Engineering Education and Workforce Capacity SE Capstone Project APRIL 2012 Report Documentation Page Form ApprovedOMB No. 0704

Maximizing Employment Outcomes through the Use of "Lower-Tech" Assistive Technology & Rehabilitation Engineering.

PubMed

Grott, Ray

2015-01-01

For many people with disabilities, Assistive Technology tools and Rehabilitation Engineering principles are key to successful employment outcomes. At the same time, employers and service providers are often under the impression that accommodations and AT solutions require high-tech, complicated, and expensive technologies. This paper discusses how creative problem solving and a "keep it simple" mindset can result in very functional low-cost solutions.

Ion Engine Grid Gap Measurements

NASA Technical Reports Server (NTRS)

Soulas, Gerge C.; Frandina, Michael M.

2004-01-01

A simple technique for measuring the grid gap of an ion engine s ion optics during startup and steady-state operation was demonstrated with beam extraction. The grid gap at the center of the ion optics assembly was measured with a long distance microscope that was focused onto an alumina pin that protruded through the center accelerator grid aperture and was mechanically attached to the screen grid. This measurement technique was successfully applied to a 30 cm titanium ion optics assembly mounted onto an NSTAR engineering model ion engine. The grid gap and each grid s movement during startup from room temperature to both full and low power were measured. The grid gaps with and without beam extraction were found to be significantly different. The grid gaps at the ion optics center were both significantly smaller than the cold grid gap and different at the two power levels examined. To avoid issues associated with a small grid gap during thruster startup with titanium ion optics, a simple method was to operate the thruster initially without beam extraction to heat the ion optics. Another possible method is to apply high voltage to the grids prior to igniting the discharge because power deposition to the grids from the plasma is lower with beam extraction than without. Further testing would be required to confirm this approach.

How authors did it - a methodological analysis of recent engineering education research papers in the European Journal of Engineering Education

NASA Astrophysics Data System (ADS)

Malmi, Lauri; Adawi, Tom; Curmi, Ronald; de Graaff, Erik; Duffy, Gavin; Kautz, Christian; Kinnunen, Päivi; Williams, Bill

2018-03-01

We investigated research processes applied in recent publications in the European Journal of Engineering Education (EJEE), exploring how papers link to theoretical work and how research processes have been designed and reported. We analysed all 155 papers published in EJEE in 2009, 2010 and 2013, classifying the papers using a taxonomy of research processes in engineering education research (EER) (Malmi et al. 2012). The majority of the papers presented either empirical work (59%) or were case reports (27%). Our main findings are as follows: (1) EJEE papers build moderately on a wide selection of theoretical work; (2) a great majority of papers have a clear research strategy, but data analysis methods are mostly simple descriptive statistics or simple/undocumented qualitative research methods; and (3) there are significant shortcomings in reporting research questions, methodology and limitations of studies. Our findings are consistent with and extend analyses of EER papers in other publishing venues; they help to build a clearer picture of the research currently published in EJEE and allow us to make recommendations for consideration by the editorial team of the journal. Our employed procedure also provides a framework that can be applied to monitor future global evolution of this and other EER journals.

Chorioallantoic membrane for in vivo investigation of tissue-engineered construct biocompatibility.

PubMed

Baiguera, Silvia; Macchiarini, Paolo; Ribatti, Domenico

2012-07-01

In tissue engineering approach, the scaffold plays a key role for a suitable outcome of cell-scaffold interactions and for the success of tissue healing and regeneration. As a consequence, the characterization of scaffold properties and the in vivo evaluation of tissue responses and effects result to be essential in the development of suitable implantable device. Among the in vivo methods, the chick embryo chorioallantoic membrane (CAM) assay represents a rather simple and cost-effective procedure to study the biocompatibility responses of graft materials. CAM is indeed characterized by low experiment costs, simplicity, relative speed in obtaining the expected results, limited ethical concern, no need of high-level technical skill, and the absence of a mature immune system, resulting in an inexpensive, simple, and practical method to evaluate and characterize tissue-engineered constructs. The results till now obtained suggest that CAM assay can be used as a pre-screening assay, before in vivo animal studies, to determine whether the scaffold is liable to cause an adverse reaction and to evaluate its future enhancement of existing materials for tissue engineering. A review of the more recent results related to the use of CAM for in vivo biomaterial property evaluation is herein reported. Copyright © 2012 Wiley Periodicals, Inc.

Some single-piston closed-cycle machines and Peter Tailer's thermal lag engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

West, C.D.

1993-01-01

Peter Tailer has devised, built, and operated a beautifully simple engine with a closed working gas cycle, external heating, and only a single piston. The aim of this paper is to cast some light on the possible modes of operation for his machine. The methods develops to analyze certain aspects of Stirling cycle engines, and especially the thermodynamic losses incurred in systems that are neither perfectly isothermal nor perfectly adiabatic, can be applied to Tailer's system. The results identify two idealized cycles fr such machines; relate those cycles to a single piston, ported cylinder machine proposed earlier; and offer amore » possible explanation for the success of the thermal lag engine.« less

A design study of a reaction control system for a V/STOL fighter/attack aircraft

NASA Technical Reports Server (NTRS)

Beard, B. B.; Foley, W. H.

1983-01-01

Attention is given to a short takeoff vertical landing (STOVL) aircraft reaction control system (RCS) design study. The STOVL fighter/attack aircraft employs an existing turbofan engine, and its hover requirement places a premium on weight reduction, which eliminates prospective nonairbreathing RCSs. A simple engine compressor bleed RCS degrades overall performance to an unacceptable degree, and the supersonic requirement precludes the large volume alternatives of thermal or ejector thrust augmentation systems as well as the ducting of engine exhaust gases and the use of a dedicated turbojet. The only system which addressed performance criteria without requiring major engine modifications was a dedicated load compressor driven by an auxilliary power unit.

A Physics-Based Engineering Methodology for Calculating Soft Error Rates of Bulk CMOS and SiGe Heterojunction Bipolar Transistor Integrated Circuits

NASA Astrophysics Data System (ADS)

Fulkerson, David E.

2010-02-01

This paper describes a new methodology for characterizing the electrical behavior and soft error rate (SER) of CMOS and SiGe HBT integrated circuits that are struck by ions. A typical engineering design problem is to calculate the SER of a critical path that commonly includes several circuits such as an input buffer, several logic gates, logic storage, clock tree circuitry, and an output buffer. Using multiple 3D TCAD simulations to solve this problem is too costly and time-consuming for general engineering use. The new and simple methodology handles the problem with ease by simple SPICE simulations. The methodology accurately predicts the measured threshold linear energy transfer (LET) of a bulk CMOS SRAM. It solves for circuit currents and voltage spikes that are close to those predicted by expensive 3D TCAD simulations. It accurately predicts the measured event cross-section vs. LET curve of an experimental SiGe HBT flip-flop. The experimental cross section vs. frequency behavior and other subtle effects are also accurately predicted.

Automated Data Tagging in the HLA

NASA Astrophysics Data System (ADS)

Gaffney, N. I.; Miller, W. W.

2008-08-01

One of the more powerful and popular forms of data organization implemented in most popular information sharing web applications is data tagging. With a rich user base from which to gather and digest tags, many interesting and often unanticipated yet very useful associations are revealed. With regard to an existing information, the astronomical community has a rich pool of existing digitally stored and searchable data than any of the currently popular web community, such as You Tube or My Space, had when they started. In initial experiments with the search engine for the Hubble Legacy Archive, we have created a simple yet powerful scheme by which the information from a footprint service, the NED and SIMBAD catalog services, and the ADS abstracts and keywords can be used to initially tag data with standard keywords. By then ingesting this into a public ally available information search engine, such as Apache Lucene, one can create a simple and powerful data tag search engine and association system. By then augmenting this with user provided keys and usage pattern analysis, one can produce a powerful modern data mining system for any astronomical data warehouse.

[Transcription activator-like effectors(TALEs)based genome engineering].

PubMed

Zhao, Mei-Wei; Duan, Cheng-Li; Liu, Jiang

2013-10-01

Systematic reverse-engineering of functional genome architecture requires precise modifications of gene sequences and transcription levels. The development and application of transcription activator-like effectors(TALEs) has created a wealth of genome engineering possibilities. TALEs are a class of naturally occurring DNA-binding proteins found in the plant pathogen Xanthomonas species. The DNA-binding domain of each TALE typically consists of tandem 34-amino acid repeat modules rearranged according to a simple cipher to target new DNA sequences. Customized TALEs can be used for a wide variety of genome engineering applications, including transcriptional modulation and genome editing. Such "genome engineering" has now been established in human cells and a number of model organisms, thus opening the door to better understanding gene function in model organisms, improving traits in crop plants and treating human genetic disorders.

SPIKE-2: a Practical Stirling Engine for Kilowatt Level Solar Power

NASA Technical Reports Server (NTRS)

Beale, W. T.

1984-01-01

Recent advances in the art of free piston Stirling engine design make possible the production of 1-10kW free piston Stirling linear alternator engine, hermetically sealed, efficient, durable and simple in construction and operation. Power output is in the form of single or three phase 60 Hz. AC, or DC. The three phase capability is available from single machines without need of external conditioning. Engine voltage control regains set voltage within 5 cycles in response to any load change. The existing SPIKE-2 design has an engine alternator efficiency of 25% at 650 C heater wall temperature and a service life of over three years in solar service. The same system can be scaled over a range of at least 100 watts to 25kW.

User manual for two simple postscript output FORTRAN plotting routines

NASA Technical Reports Server (NTRS)

Nguyen, T. X.

1991-01-01

Graphics is one of the important tools in engineering analysis and design. However, plotting routines that generate output on high quality laser printers normally come in graphics packages, which tend to be expensive and system dependent. These factors become important for small computer systems or desktop computers, especially when only some form of a simple plotting routine is sufficient. With the Postscript language becoming popular, there are more and more Postscript laser printers now available. Simple, versatile, low cost plotting routines that can generate output on high quality laser printers are needed and standard FORTRAN language plotting routines using output in Postscript language seems logical. The purpose here is to explain two simple FORTRAN plotting routines that generate output in Postscript language.

Supercharged two-cycle engines employing novel single element reciprocating shuttle inlet valve mechanisms and with a variable compression ratio

NASA Technical Reports Server (NTRS)

Wiesen, Bernard (Inventor)

2008-01-01

This invention relates to novel reciprocating shuttle inlet valves, effective with every type of two-cycle engine, from small high-speed single cylinder model engines, to large low-speed multiple cylinder engines, employing spark or compression ignition. Also permitting the elimination of out-of-phase piston arrangements to control scavenging and supercharging of opposed-piston engines. The reciprocating shuttle inlet valve (32) and its operating mechanism (34) is constructed as a single and simple uncomplicated member, in combination with the lost-motion abutments, (46) and (48), formed in a piston skirt, obviating the need for any complex mechanisms or auxiliary drives, unaffected by heat, friction, wear or inertial forces. The reciprocating shuttle inlet valve retains the simplicity and advantages of two-cycle engines, while permitting an increase in volumetric efficiency and performance, thereby increasing the range of usefulness of two-cycle engines into many areas that are now dominated by the four-cycle engine.

NEW APPROACHES: A hot air balloon from dustbin liners

NASA Astrophysics Data System (ADS)

Weaver, Nicholas

1998-07-01

This article describes how a simple hot air balloon, inflated by a hair dryer, can be made out of household bin liners and Sellotape. It can be used at sixth-form level as an application of the ideal gas equation, = constant, and is rather more exciting than heated pistons. It gives a taste of a simple engineering design process, although the students do have to be reasonably adept at geometry and algebra.

Analytical determination of space station response to crew motion and design of suspension system for microgravity experiments

NASA Technical Reports Server (NTRS)

Liu, F. C.

1986-01-01

The objective of this investigation is to make analytical determination of the acceleration produced by crew motion in an orbiting space station and define design parameters for the suspension system of microgravity experiments. A simple structural model for simulation of the IOC space station is proposed. Mathematical formulation of this model provides the engineers a simple and direct tool for designing an effective suspension system.

Efficient Parallel Engineering Computing on Linux Workstations

NASA Technical Reports Server (NTRS)

Lou, John Z.

2010-01-01

A C software module has been developed that creates lightweight processes (LWPs) dynamically to achieve parallel computing performance in a variety of engineering simulation and analysis applications to support NASA and DoD project tasks. The required interface between the module and the application it supports is simple, minimal and almost completely transparent to the user applications, and it can achieve nearly ideal computing speed-up on multi-CPU engineering workstations of all operating system platforms. The module can be integrated into an existing application (C, C++, Fortran and others) either as part of a compiled module or as a dynamically linked library (DLL).

An intelligent instrument for measuring exhaust temperature of marine engine

NASA Astrophysics Data System (ADS)

Ma, Nan-Qi; Su, Hua; Liu, Jun

2006-12-01

Exhaust temperature of the marine engine is commonly measured through thermocouple. Measure deviation will occur after using the thermocouple for some time due to nonlinearity of thermocouple itself, high temperature and chemical corrosion of measure point. Frequent replacement of thermocouple will increase the operating cost. This paper designs a new intelligent instrument for solving the above-mentioned problems of the marine engine temperature measurement, which combines the conventional thermocouple temperature measurement technology and SCM(single chip microcomputer). The reading of the thermocouple is simple and precise and the calibration can be made automatically and manually.

Combustion Control System Design of Diesel Engine via ASPR based Output Feedback Control Strategy with a PFC

NASA Astrophysics Data System (ADS)

Mizumoto, Ikuro; Tsunematsu, Junpei; Fujii, Seiya

2016-09-01

In this paper, a design method of an output feedback control system with a simple feedforward input for a combustion model of diesel engine will be proposed based on the almost strictly positive real-ness (ASPR-ness) of the controlled system for a combustion control of diesel engines. A parallel feedforward compensator (PFC) design scheme which renders the resulting augmented controlled system ASPR will also be proposed in order to design a stable output feedback control system for the considered combustion model. The effectiveness of our proposed method will be confirmed through numerical simulations.

Efficiency and its bounds for thermal engines at maximum power using Newton's law of cooling.

PubMed

Yan, H; Guo, Hao

2012-01-01

We study a thermal engine model for which Newton's cooling law is obeyed during heat transfer processes. The thermal efficiency and its bounds at maximum output power are derived and discussed. This model, though quite simple, can be applied not only to Carnot engines but also to four other types of engines. For the long thermal contact time limit, new bounds, tighter than what were known before, are obtained. In this case, this model can simulate Otto, Joule-Brayton, Diesel, and Atkinson engines. While in the short contact time limit, which corresponds to the Carnot cycle, the same efficiency bounds as that from Esposito et al. [Phys. Rev. Lett. 105, 150603 (2010)] are derived. In both cases, the thermal efficiency decreases as the ratio between the heat capacities of the working medium during heating and cooling stages increases. This might provide instructions for designing real engines. © 2012 American Physical Society

Cardiac tissue engineering: state of the art.

PubMed

Hirt, Marc N; Hansen, Arne; Eschenhagen, Thomas

2014-01-17

The engineering of 3-dimensional (3D) heart muscles has undergone exciting progress for the past decade. Profound advances in human stem cell biology and technology, tissue engineering and material sciences, as well as prevascularization and in vitro assay technologies make the first clinical application of engineered cardiac tissues a realistic option and predict that cardiac tissue engineering techniques will find widespread use in the preclinical research and drug development in the near future. Tasks that need to be solved for this purpose include standardization of human myocyte production protocols, establishment of simple methods for the in vitro vascularization of 3D constructs and better maturation of myocytes, and, finally, thorough definition of the predictive value of these methods for preclinical safety pharmacology. The present article gives an overview of the present state of the art, bottlenecks, and perspectives of cardiac tissue engineering for cardiac repair and in vitro testing.

DEAN: A program for dynamic engine analysis

NASA Technical Reports Server (NTRS)

Sadler, G. G.; Melcher, K. J.

1985-01-01

The Dynamic Engine Analysis program, DEAN, is a FORTRAN code implemented on the IBM/370 mainframe at NASA Lewis Research Center for digital simulation of turbofan engine dynamics. DEAN is an interactive program which allows the user to simulate engine subsystems as well as a full engine systems with relative ease. The nonlinear first order ordinary differential equations which define the engine model may be solved by one of four integration schemes, a second order Runge-Kutta, a fourth order Runge-Kutta, an Adams Predictor-Corrector, or Gear's method for still systems. The numerical data generated by the model equations are displayed at specified intervals between which the user may choose to modify various parameters affecting the model equations and transient execution. Following the transient run, versatile graphics capabilities allow close examination of the data. DEAN's modeling procedure and capabilities are demonstrated by generating a model of simple compressor rig.

Critical Design Parameters for Pylon-Aided Gaseous Fuel Injection Upstream of a Flameholding Cavity

DTIC Science & Technology

2009-03-01

Spencer Bowen and Neil Rogers was critical to not only the successful completion of this research but my sanity as well. The care, support, and motivation...missile presents a relatively inexpensive alternative that while complex is much more feasible to achieve in the near term. The hypersonic bomber and...scramjet engine operates supersonically throughout. Though aerodynamically complex the scramjet engine is relatively simple, consisting of an inlet

The ABC's required for establishing a practical computerized plant engineering management data base system

NASA Technical Reports Server (NTRS)

Maiocco, F. R.; Hume, J. P.

1976-01-01

A system's approach is outlined in the paper to assist facility and Plant Engineers improve their organization's data management system. The six basic steps identified may appear somewhat simple; however, adequate planning, proper resources, and the involvement of management will determine the success of a computerized facility management data base. Helpful suggestions are noted throughout the paper to insure the development of a practical computerized data management system.

Teaching biomedical applications to secondary students.

PubMed

Openshaw, S; Fleisher, A; Ljunggren, C

1999-01-01

Certain aspects of biomedical engineering applications lend themselves well to experimentation that can be done by high school students. This paper describes two experiments done during a six-week summer internship program in which two high school students used electrodes, circuit boards, and computers to mimic a sophisticated heart monitor and also to control a robotic car. Our experience suggests that simple illustrations of complex instrumentation can be effective in introducing adolescents to the biomedical engineering field.

A thermoacoustic Stirling heat engine

NASA Astrophysics Data System (ADS)

Backhaus, S.; Swift, G. W.

1999-05-01

Electrical and mechanical power, together with other forms of useful work, are generated worldwide at a rate of about 1012 watts, mostly using heat engines. The efficiency of such engines is limited by the laws of thermodynamics and by practical considerations such as the cost of building and operating them. Engines with high efficiency help to conserve fossil fuels and other natural resources, reducing global-warming emissions and pollutants. In practice, the highest efficiencies are obtained only in the most expensive, sophisticated engines, such as the turbines in central utility electrical plants. Here we demonstrate an inexpensive thermoacoustic engine that employs the inherently efficient Stirling cycle. The design is based on a simple acoustic apparatus with no moving parts. Our first small laboratory prototype, constructed using inexpensive hardware (steel pipes), achieves an efficiency of 0.30, which exceeds the values of 0.10-0.25 attained in other heat engines, with no moving parts. Moreover, the efficiency of our prototype is comparable to that of the common internal combustion engine (0.25-0.40) and piston-driven Stirling engines, (0.20-0.38).

A new technique for thermodynamic engine modeling

NASA Astrophysics Data System (ADS)

Matthews, R. D.; Peters, J. E.; Beckel, S. A.; Shizhi, M.

1983-12-01

Reference is made to the equations given by Matthews (1983) for piston engine performance, which show that this performance depends on four fundamental engine efficiencies (combustion, thermodynamic cycle or indicated thermal, volumetric, and mechanical) as well as on engine operation and design parameters. This set of equations is seen to suggest a different technique for engine modeling; that is, that each efficiency should be modeled individually and the efficiency submodels then combined to obtain an overall engine model. A simple method for predicting the combustion efficiency of piston engines is therefore required. Various methods are proposed here and compared with experimental results. These combustion efficiency models are then combined with various models for the volumetric, mechanical, and indicated thermal efficiencies to yield three different engine models of varying degrees of sophistication. Comparisons are then made of the predictions of the resulting engine models with experimental data. It is found that combustion efficiency is almost independent of load, speed, and compression ratio and is not strongly dependent on fuel type, at least so long as the hydrogen-to-carbon ratio is reasonably close to that for isooctane.

Approximate method for calculating convective heat flux on the surface of bodies of simple geometric shapes

NASA Astrophysics Data System (ADS)

Kuzenov, V. V.; Ryzhkov, S. V.

2017-02-01

The paper formulated engineering and physical mathematical model for aerothermodynamics hypersonic flight vehicle (HFV) in laminar and turbulent boundary layers (model designed for an approximate estimate of the convective heat flow in the range of speeds M = 6-28, and height H = 20-80 km). 2D versions of calculations of convective heat flows for bodies of simple geometric forms (individual elements of the design HFV) are presented.

Thermal-Stress Reducer For Metal/Composite Joint

NASA Technical Reports Server (NTRS)

Glinski, Robert L.

1993-01-01

Simple insert called "thermal link" reduces stresses caused by mismatches between thermal expansions of metal part and nonmetallic part made of fiber/matrix composite material. Link conceived for use in casing of advanced jet engine.

It's Not So Simple

ERIC Educational Resources Information Center

Krebs, Donald F.

1975-01-01

An audiologist takes issue with statements by the director of the National Institute for Rehabilitation Engineering which suggest that telephones with acoustic coupling devices will be as effective for hard of hearing persons as those with magnetic coupling. (GW)

A Five Dollar Physics Experiment

ERIC Educational Resources Information Center

Jacobson, David

1973-01-01

Describes the construction of a simple apparatus capable of converting solar energy into mechanical energy. Construction of the engine'' is inexpensive, and should stimulate student interest in the idea of producing power directly from the sun. (JR)

Some single-piston closed-cycle machines and Peter Tailer`s thermal lag engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

West, C.D.

1993-06-01

Peter Tailer has devised, built, and operated a beautifully simple engine with a closed working gas cycle, external heating, and only a single piston. The aim of this paper is to cast some light on the possible modes of operation for his machine. The methods develops to analyze certain aspects of Stirling cycle engines, and especially the thermodynamic losses incurred in systems that are neither perfectly isothermal nor perfectly adiabatic, can be applied to Tailer`s system. The results identify two idealized cycles fr such machines; relate those cycles to a single piston, ported cylinder machine proposed earlier; and offer amore » possible explanation for the success of the thermal lag engine.« less

Building a computer-aided design capability using a standard time share operating system

NASA Technical Reports Server (NTRS)

Sobieszczanski, J.

1975-01-01

The paper describes how an integrated system of engineering computer programs can be built using a standard commercially available operating system. The discussion opens with an outline of the auxiliary functions that an operating system can perform for a team of engineers involved in a large and complex task. An example of a specific integrated system is provided to explain how the standard operating system features can be used to organize the programs into a simple and inexpensive but effective system. Applications to an aircraft structural design study are discussed to illustrate the use of an integrated system as a flexible and efficient engineering tool. The discussion concludes with an engineer's assessment of an operating system's capabilities and desirable improvements.

An Exact Efficiency Formula for Holographic Heat Engines

DOE PAGES

Johnson, Clifford

2016-03-31

Further consideration is given to the efficiency of a class of black hole heat engines that perform mechanical work via the pdV terms present in the First Law of extended gravitational thermodynamics. It is noted that, when the engine cycle is a rectangle with sides parallel to the (p,V) axes, the efficiency can be written simply in terms of the mass of the black hole evaluated at the corners. Since an arbitrary cycle can be approximated to any desired accuracy by a tiling of rectangles, a general geometrical algorithm for computing the efficiency of such a cycle follows. Finally, amore » simple generalization of the algorithm renders it applicable to broader classes of heat engine, even beyond the black hole context.« less

A hybrid disturbance rejection control solution for variable valve timing system of gasoline engines.

PubMed

Xie, Hui; Song, Kang; He, Yu

2014-07-01

A novel solution for electro-hydraulic variable valve timing (VVT) system of gasoline engines is proposed, based on the concept of active disturbance rejection control (ADRC). Disturbances, such as oil pressure and engine speed variations, are all estimated and mitigated in real-time. A feed-forward controller was added to enhance the performance of the system based on a simple and static first principle model, forming a hybrid disturbance rejection control (HDRC) strategy. HDRC was validated by experimentation and compared with an existing manually tuned proportional-integral (PI) controller. The results show that HDRC provided a faster response and better tolerance of engine speed and oil pressure variations. © 2013 ISA Published by ISA All rights reserved.

Lightweight engine containment. [Kevlar shielding

NASA Technical Reports Server (NTRS)

Weaver, A. T.

1977-01-01

Kevlar fabric styles and weaves were studied, as well as methods of application for advanced gas turbine engines. The Kevlar material was subjected to high speed impacts by simple projectiles fired from a rifle, as well as more complex shapes such as fan blades released from gas turbine rotors in a spin pit. Just contained data was developed for a variety of weave and/or application techniques, and a comparative containment weight efficiency was established for Kevlar containment applications. The data generated during these tests is being incorporated into an analytical design system so that blade containment trade-off studies between Kevlar and metal case engine structures can be made. Laboratory tests and engine environment tests were performed to determine the survivability of Kevlar in a gas turbine environment.

Enhancements to the Engine Data Interpretation System (EDIS)

NASA Technical Reports Server (NTRS)

Hofmann, Martin O.

1993-01-01

The Engine Data Interpretation System (EDIS) expert system project assists the data review personnel at NASA/MSFC in performing post-test data analysis and engine diagnosis of the Space Shuttle Main Engine (SSME). EDIS uses knowledge of the engine, its components, and simple thermodynamic principles instead of, and in addition to, heuristic rules gathered from the engine experts. EDIS reasons in cooperation with human experts, following roughly the pattern of logic exhibited by human experts. EDIS concentrates on steady-state static faults, such as small leaks, and component degradations, such as pump efficiencies. The objective of this contract was to complete the set of engine component models, integrate heuristic rules into EDIS, integrate the Power Balance Model into EDIS, and investigate modification of the qualitative reasoning mechanisms to allow 'fuzzy' value classification. The results of this contract is an operational version of EDIS. EDIS will become a module of the Post-Test Diagnostic System (PTDS) and will, in this context, provide system-level diagnostic capabilities which integrate component-specific findings provided by other modules.

Enhancements to the Engine Data Interpretation System (EDIS)

NASA Technical Reports Server (NTRS)

Hofmann, Martin O.

1993-01-01

The Engine Data Interpretation System (EDIS) expert system project assists the data review personnel at NASA/MSFC in performing post-test data analysis and engine diagnosis of the Space Shuttle Main Engine (SSME). EDIS uses knowledge of the engine, its components, and simple thermodynamic principles instead of, and in addition to, heuristic rules gathered from the engine experts. EDIS reasons in cooperation with human experts, following roughly the pattern of logic exhibited by human experts. EDIS concentrates on steady-state static faults, such as small leaks, and component degradations, such as pump efficiencies. The objective of this contract was to complete the set of engine component models, integrate heuristic rules into EDIS, integrate the Power Balance Model into EDIS, and investigate modification of the qualitative reasoning mechanisms to allow 'fuzzy' value classification. The result of this contract is an operational version of EDIS. EDIS will become a module of the Post-Test Diagnostic System (PTDS) and will, in this context, provide system-level diagnostic capabilities which integrate component-specific findings provided by other modules.

Scale-Up of GRCop: From Laboratory to Rocket Engines

NASA Technical Reports Server (NTRS)

Ellis, David L.

2016-01-01

GRCop is a high temperature, high thermal conductivity copper-based series of alloys designed primarily for use in regeneratively cooled rocket engine liners. It began with laboratory-level production of a few grams of ribbon produced by chill block melt spinning and has grown to commercial-scale production of large-scale rocket engine liners. Along the way, a variety of methods of consolidating and working the alloy were examined, a database of properties was developed and a variety of commercial and government applications were considered. This talk will briefly address the basic material properties used for selection of compositions to scale up, the methods used to go from simple ribbon to rocket engines, the need to develop a suitable database, and the issues related to getting the alloy into a rocket engine or other application.

Comparisons of Particulate Size Distributions from Multiple Combustion Strategies

NASA Astrophysics Data System (ADS)

Zhang, Yizhou

In this study, a comparison of particle size distribution (PSD) measurements from eight different combustion strategies was conducted at four different load-speed points. The PSDs were measured using a scanning mobility particle sizer (SMPS) together with a condensation particle counter (CPC). To study the influence of volatile particles, PSD measurements were performed with and without a volatile particle remover (thermodenuder, TD) at both low and high dilution ratios. The common engine platform utilized in the experiment helps to eliminate the influence of background particulate and ensures similarity in dilution conditions. The results show a large number of volatile particles were present under LDR sample conditions for most of the operating conditions. The use of a TD, especially when coupled with HDR, was demonstrated to be effective at removing volatile particles and provided consistent measurements across all combustion strategies. The PSD comparison showed that gasoline premixed combustion strategies such as HCCI and GCI generally have low PSD magnitudes for particle sizes greater than the Particle Measurement Programme (PMP) cutoff diameter (23 nm), and the PSDs were highly nuclei-mode particle dominated. The strategies using diesel as the only fuel (DLTC and CDC) generally showed the highest particle number emissions for particles larger than 23 nm and had accumulation-mode particle dominated PSDs. A consistent correlation between the increase of the direct-injection of diesel fuel and a higher fraction of accumulation-mode particles was observed over all combustion strategies. A DI fuel substitution study and injector nozzle geometry study were conducted to better understand the correlation between PSD shape and DI fueling. It was found that DI fuel properties has a clear impact on PSD behavior for CDC and NG DPI. Fuel with lower density and lower sooting tendency led to a nuclei-mode particle dominated PSD shape. For NG RCCI, accumulation-mode particle concentration was found to be insensitive to DI fuel properties. Similar PSD behavior of increased nuclei-mode particle fraction was also observed when a smaller orifice nozzle was used for CDC and NG DPI operation. For NG DPI, a reduction of DI fuel fraction generally led to a reduction in accumulation-mode particles.

Examination of Various Methods Used in Support of Concurrent Engineering

DTIC Science & Technology

1990-03-01

1989. F.Y.I. Drawing a2Ther Productivity. Industrial Engineering 21: 80. Ishi82 Ishikawa , Kaoru . 1982. Guide to Quality Control. White Plains, NY: Kraus...observe it in practice have an easier time identifying the different methods or tech- niques (such as the Ishikawa tools) used than understanding the...simple histogram to show what prob- lems should be attacked first. Cause and Effect Diagrams Sometimes called the fishbone or Ishikawa diagrams-a kind

Air and Space Power Journal. Volume 17, Number 2, Summer 2003

DTIC Science & Technology

2003-01-01

aircraft especially designed for close air support of ground forces. This simple, effective, and survivable twin- engine jet aircraft can be used against...In “Allied Airpower Comes of Age: The Roles and Contributions of Airpower to the Italian Cam­ paign,” Maj Robert A. Renner analyzes the fight for air ...means treating the development of Air Force personnel as a weapon system, which is created by using a systems- engineering approach and the best

Operations Research Center. Annual Report. Jul 1, 1977 through June 30, 1978.

DTIC Science & Technology

1978-06-30

The Center’s commitment in this area is illustrated, for instance, by a new two-week summer course it is offering for the first time, "Recent...published in the summer of 1978. Some simple indications of the findings are (1) about half of the people presently eligible to donate blood have...Schwarz and W.H. Hausman ), Stanford University Department of Industrial Engineering and Engineering Management Technical Report No. 77-4, September

A model-based gain scheduling approach for controlling the common-rail system for GDI engines

NASA Astrophysics Data System (ADS)

di Gaeta, Alessandro; Montanaro, Umberto; Fiengo, Giovanni; Palladino, Angelo; Giglio, Veniero

2012-04-01

The progressive reduction in vehicle emission requirements have forced the automotive industry to invest in research for developing alternative and more efficient control strategies. All control features and resources are permanently active in an electronic control unit (ECU), ensuring the best performance with respect to emissions, fuel economy, driveability and diagnostics, independently from engine working point. In this article, a considerable step forward has been achieved by the common-rail technology which has made possible to vary the injection pressure over the entire engine speed range. As a consequence, the injection of a fixed amount of fuel is more precise and multiple injections in a combustion cycle can be made. In this article, a novel gain scheduling pressure controller for gasoline direct injection (GDI) engine is designed to stabilise the mean fuel pressure into the rail and to track demanded pressure trajectories. By exploiting a simple control-oriented model describing the mean pressure dynamics in the rail, the control structure turns to be simple enough to be effectively implemented in commercial ECUs. Experimental results in a wide range of operating points confirm the effectiveness of the proposed control method to tame efficiently the mean value pressure dynamics of the plant showing a good accuracy and robustness with respect to unavoidable parameters uncertainties, unmodelled dynamics, and hidden coupling terms.

Highly Effective Polyphosphate Synthesis, Phosphate Removal, and Concentration Using Engineered Environmental Bacteria Based on a Simple Solo Medium-Copy Plasmid Strategy.

PubMed

Wang, Xin; Wang, Xiaomeng; Hui, Kaimin; Wei, Wei; Zhang, Wen; Miao, Aijun; Xiao, Lin; Yang, Liuyan

2018-01-02

Microbial polyphosphate (polyP) production is vital to the removal of phosphate from wastewater. However, to date, engineered polyP synthesis using genetically accessible environmental bacteria remains a challenge. This study develops a simple solo medium-copy plasmid-based polyphosphate kinase (PPK1) overexpression strategy for achieving maximum intracellular polyphosphate accumulation by environmental bacteria. The polyP content of the subsequently engineered Citrobacter freundii (CPP) could reach as high as 12.7% of its dry weight. The biomass yield of CPP was also guaranteed because of negligible metabolic burden effects resulting from the medium plasmid copy number. Consequently, substantial removal of phosphate (P i ) from the ambient environment was achieved simultaneously. Because of the need for exogenous P i for in vivo ATP regeneration, CPP could thoroughly remove P i from synthetic municipal wastewater when it was applied for the "one-step" removal of P i with a bench-scale sequence batch membrane reactor. Almost all the phosphorus except for that assimilated by CPP for cellular growth could be recovered in the form of more concentrated P i . Overall, engineering environmental bacteria to overexpress PPK1 via a solo medium-copy plasmid strategy may represent a valuable general option for not only biotechnological research based on sufficient intracellular polyP production but also removal of P i from wastewater and P i enrichment.

Production of Renewable Diesel Fuel

DOT National Transportation Integrated Search

2012-06-01

Vegetable oils have been investigated as a way to provide a renewable source for diesel fuel. A successful approach to using : vegetable oils in diesel engines has been transesterification of the oils with simple alcohols to produce mono-alkyl esters...

Minimizing the effects of pile driving vibrations : research spotlight.

DOT National Transportation Integrated Search

2013-11-01

Engineers must take care that the vibrations from pile driving : operations during bridge construction do not damage underground : utilities or cause settlement in the foundations of nearby structures. : In this project, researchers developed a simpl...

A Physics-Based Engineering Approach to Predict the Cross Section for Advanced SRAMs

NASA Astrophysics Data System (ADS)

Li, Lei; Zhou, Wanting; Liu, Huihua

2012-12-01

This paper presents a physics-based engineering approach to estimate the heavy ion induced upset cross section for 6T SRAM cells from layout and technology parameters. The new approach calculates the effects of radiation with junction photocurrent, which is derived based on device physics. The new and simple approach handles the problem by using simple SPICE simulations. At first, the approach uses a standard SPICE program on a typical PC to predict the SPICE-simulated curve of the collected charge vs. its affected distance from the drain-body junction with the derived junction photocurrent. And then, the SPICE-simulated curve is used to calculate the heavy ion induced upset cross section with a simple model, which considers that the SEU cross section of a SRAM cell is more related to a “radius of influence” around a heavy ion strike than to the physical size of a diffusion node in the layout for advanced SRAMs in nano-scale process technologies. The calculated upset cross section based on this method is in good agreement with the test results for 6T SRAM cells processed using 90 nm process technology.

Multimedia modeling of engineered nanoparticles with SimpleBox4nano: model definition and evaluation.

PubMed

Meesters, Johannes A J; Koelmans, Albert A; Quik, Joris T K; Hendriks, A Jan; van de Meent, Dik

2014-05-20

Screening level models for environmental assessment of engineered nanoparticles (ENP) are not generally available. Here, we present SimpleBox4Nano (SB4N) as the first model of this type, assess its validity, and evaluate it by comparisons with a known material flow model. SB4N expresses ENP transport and concentrations in and across air, rain, surface waters, soil, and sediment, accounting for nanospecific processes such as aggregation, attachment, and dissolution. The model solves simultaneous mass balance equations (MBE) using simple matrix algebra. The MBEs link all concentrations and transfer processes using first-order rate constants for all processes known to be relevant for ENPs. The first-order rate constants are obtained from the literature. The output of SB4N is mass concentrations of ENPs as free dispersive species, heteroaggregates with natural colloids, and larger natural particles in each compartment in time and at steady state. Known scenario studies for Switzerland were used to demonstrate the impact of the transport processes included in SB4N on the prediction of environmental concentrations. We argue that SB4N-predicted environmental concentrations are useful as background concentrations in environmental risk assessment.

Aircraft stress sequence development: A complex engineering process made simple

NASA Technical Reports Server (NTRS)

Schrader, K. H.; Butts, D. G.; Sparks, W. A.

1994-01-01

Development of stress sequences for critical aircraft structure requires flight measured usage data, known aircraft loads, and established relationships between aircraft flight loads and structural stresses. Resulting cycle-by-cycle stress sequences can be directly usable for crack growth analysis and coupon spectra tests. Often, an expert in loads and spectra development manipulates the usage data into a typical sequence of representative flight conditions for which loads and stresses are calculated. For a fighter/trainer type aircraft, this effort is repeated many times for each of the fatigue critical locations (FCL) resulting in expenditure of numerous engineering hours. The Aircraft Stress Sequence Computer Program (ACSTRSEQ), developed by Southwest Research Institute under contract to San Antonio Air Logistics Center, presents a unique approach for making complex technical computations in a simple, easy to use method. The program is written in Microsoft Visual Basic for the Microsoft Windows environment.

Electronic control of gene expression and cell behaviour in Escherichia coli through redox signalling

NASA Astrophysics Data System (ADS)

Tschirhart, Tanya; Kim, Eunkyoung; McKay, Ryan; Ueda, Hana; Wu, Hsuan-Chen; Pottash, Alex Eli; Zargar, Amin; Negrete, Alejandro; Shiloach, Joseph; Payne, Gregory F.; Bentley, William E.

2017-01-01

The ability to interconvert information between electronic and ionic modalities has transformed our ability to record and actuate biological function. Synthetic biology offers the potential to expand communication `bandwidth' by using biomolecules and providing electrochemical access to redox-based cell signals and behaviours. While engineered cells have transmitted molecular information to electronic devices, the potential for bidirectional communication stands largely untapped. Here we present a simple electrogenetic device that uses redox biomolecules to carry electronic information to engineered bacterial cells in order to control transcription from a simple synthetic gene circuit. Electronic actuation of the native transcriptional regulator SoxR and transcription from the PsoxS promoter allows cell response that is quick, reversible and dependent on the amplitude and frequency of the imposed electronic signals. Further, induction of bacterial motility and population based cell-to-cell communication demonstrates the versatility of our approach and potential to drive intricate biological behaviours.

Improved NASA-ANOPP Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems. Volume 2; Fan Suppression Model Development

NASA Technical Reports Server (NTRS)

Kontos, Karen B.; Kraft, Robert E.; Gliebe, Philip R.

1996-01-01

The Aircraft Noise Predication Program (ANOPP) is an industry-wide tool used to predict turbofan engine flyover noise in system noise optimization studies. Its goal is to provide the best currently available methods for source noise prediction. As part of a program to improve the Heidmann fan noise model, models for fan inlet and fan exhaust noise suppression estimation that are based on simple engine and acoustic geometry inputs have been developed. The models can be used to predict sound power level suppression and sound pressure level suppression at a position specified relative to the engine inlet.

Cartilage tissue engineering: recent advances and perspectives from gene regulation/therapy.

PubMed

Li, Kuei-Chang; Hu, Yu-Chen

2015-05-01

Diseases in articular cartilages affect millions of people. Despite the relatively simple biochemical and cellular composition of articular cartilages, the self-repair ability of cartilage is limited. Successful cartilage tissue engineering requires intricately coordinated interactions between matrerials, cells, biological factors, and phycial/mechanical factors, and still faces a multitude of challenges. This article presents an overview of the cartilage biology, current treatments, recent advances in the materials, biological factors, and cells used in cartilage tissue engineering/regeneration, with strong emphasis on the perspectives of gene regulation (e.g., microRNA) and gene therapy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Universal Trade-Off between Power, Efficiency, and Constancy in Steady-State Heat Engines

NASA Astrophysics Data System (ADS)

Pietzonka, Patrick; Seifert, Udo

2018-05-01

Heat engines should ideally have large power output, operate close to Carnot efficiency and show constancy, i.e., exhibit only small fluctuations in this output. For steady-state heat engines, driven by a constant temperature difference between the two heat baths, we prove that out of these three requirements only two are compatible. Constancy enters quantitatively the conventional trade-off between power and efficiency. Thus, we rationalize and unify recent suggestions for overcoming this simple trade-off. Our universal bound is illustrated for a paradigmatic model of a quantum dot solar cell and for a Brownian gyrator delivering mechanical work against an external force.

Towards organ printing: engineering an intra-organ branched vascular tree.

PubMed

Visconti, Richard P; Kasyanov, Vladimir; Gentile, Carmine; Zhang, Jing; Markwald, Roger R; Mironov, Vladimir

2010-03-01

Effective vascularization of thick three-dimensional engineered tissue constructs is a problem in tissue engineering. As in native organs, a tissue-engineered intra-organ vascular tree must be comprised of a network of hierarchically branched vascular segments. Despite this requirement, current tissue-engineering efforts are still focused predominantly on engineering either large-diameter macrovessels or microvascular networks. We present the emerging concept of organ printing or robotic additive biofabrication of an intra-organ branched vascular tree, based on the ability of vascular tissue spheroids to undergo self-assembly. The feasibility and challenges of this robotic biofabrication approach to intra-organ vascularization for tissue engineering based on organ-printing technology using self-assembling vascular tissue spheroids including clinically relevantly vascular cell sources are analyzed. It is not possible to engineer 3D thick tissue or organ constructs without effective vascularization. An effective intra-organ vascular system cannot be built by the simple connection of large-diameter vessels and microvessels. Successful engineering of functional human organs suitable for surgical implantation will require concomitant engineering of a 'built in' intra-organ branched vascular system. Organ printing enables biofabrication of human organ constructs with a 'built in' intra-organ branched vascular tree.

Modeling and Detection of Ice Particle Accretion in Aircraft Engine Compression Systems

NASA Technical Reports Server (NTRS)

May, Ryan D.; Simon, Donald L.; Guo, Ten-Huei

2012-01-01

The accretion of ice particles in the core of commercial aircraft engines has been an ongoing aviation safety challenge. While no accidents have resulted from this phenomenon to date, numerous engine power loss events ranging from uneventful recoveries to forced landings have been recorded. As a first step to enabling mitigation strategies during ice accretion, a detection scheme must be developed that is capable of being implemented on board modern engines. In this paper, a simple detection scheme is developed and tested using a realistic engine simulation with approximate ice accretion models based on data from a compressor design tool. These accretion models are implemented as modified Low Pressure Compressor maps and have the capability to shift engine performance based on a specified level of ice blockage. Based on results from this model, it is possible to detect the accretion of ice in the engine core by observing shifts in the typical sensed engine outputs. Results are presented in which, for a 0.1 percent false positive rate, a true positive detection rate of 98 percent is achieved.

Utilization of waste glycerin to fuelling of spark ignition engines

NASA Astrophysics Data System (ADS)

Stelmasiak, Z.; Pietras, D.

2016-09-01

The paper discusses a possibilities of usage a simple alcohols to fuelling of spark ignition engines. Methanol and blends of methanol with glycerin, being a waste product from production of bio-components to fuels based on rapeseed oil, have been used in course of the investigations. The main objective of the research was to determine possibilities of utilization of glycerin to blending of engine fuels. The investigations have been performed using the Fiat 1100 MPI engine. Parameters obtained with the engine powered by pure methanol and by methanol- glycerin mixtures with 10÷30%vol content of glycerin were compared to parameters of the engine fuelled conventionally with the E95 gasoline. The investigations have shown increase of overall efficiency of the engine run on pure methanol with 2.5÷5.0%, and run on the mixture having 10% addition of glycerin with 2.0÷7.8%. Simultaneously, fuelling of the engine with the investigated alcohols results in reduced concentration of toxic components in exhaust gases like: CO, THC and NOx, as well as the greenhouse gas CO2.

Divergence thrust loss calculations for convergent-divergent nozzles: Extensions to the classical case

NASA Technical Reports Server (NTRS)

Berton, Jeffrey J.

1991-01-01

The analytical derivations of the non-axial thrust divergence losses for convergent-divergent nozzles are described as well as how these calculations are embodied in the Navy/NASA engine computer program. The convergent-divergent geometries considered are simple classic axisymmetric nozzles, two dimensional rectangular nozzles, and axisymmetric and two dimensional plug nozzles. A simple, traditional, inviscid mathematical approach is used to deduce the influence of the ineffectual non-axial thrust as a function of the nozzle exit divergence angle.

Recent developments in chaotic dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ott, E.

1994-02-01

Before the relatively recent wide acceptance of the existence of chaotic dynamics, many physicists and engineers were under the impression that simple systems could necessarily only display simple solutions. This feeling had been unintentionally reinforced by conventional college courses which emphasize linear dynamics (partly because that is the only case with nice general solutions). More recently, physical experiments and numerical examples have abundantly demonstrated how wrong this feeling is. A brief review of chaotic dynamics is presented. Topics discussed include basic concepts, recent developments, and applications.

Relation between Spark-Ignition Engine Knock, Detonation Waves, and Autoignition as Shown by High-Speed Photography

DTIC Science & Technology

1946-01-01

unfortunate” fiat this work has not, in the past few years , received more carcf~ll considera- tion. Th~ photographs of %kolik and Voinov wcro taken through a...with the propo8ed combined theory but not with either the simple autoignition theory or the simple detonation- wace theory. INTRODUCTION Knock is one of...countries for about 25 yeara. The past researches on knock have uncovered an immense amount of information, not only concerning the basic nature of knock but

A simple, physically-based method for evaluating the economic costs of geo-engineering schemes

NASA Astrophysics Data System (ADS)

Garrett, T. J.

2009-04-01

The consumption of primary energy (e.g coal, oil, uranium) by the global economy is done in expectation of a return on investment. For geo-engineering schemes, however, the relationship between the primary energy consumption required and the economic return is, at first glance, quite different. The energy costs of a given scheme represent a removal of economically productive available energy to do work in the normal global economy. What are the economic implications of the energy consumption associated with geo-engineering techniques? I will present a simple thermodynamic argument that, in general, real (inflation-adjusted) economic value has a fixed relationship to the rate of global primary energy consumption. This hypothesis will be shown to be supported by 36 years of available energy statistics and a two millennia period of statistics for global economic production. What is found from this analysis is that the value in any given inflation-adjusted 1990 dollar is sustained by a constant 9.7 +/- 0.3 milliwatts of global primary energy consumption. Thus, insofar as geo-engineering is concerned, any scheme that requires some nominal fraction of continuous global primary energy output necessitates a corresponding inflationary loss of real global economic value. For example, if 1% of global energy output is required, at today's consumption rates of 15 TW this corresponds to an inflationary loss of 15 trillion 1990 dollars of real value. The loss will be less, however, if the geo-engineering scheme also enables a demonstrable enhancement to global economic production capacity through climate modification.

Relation Between Spark-Ignition Engine Knock, Detonation Waves, and Autoignition as Shown by High-Speed Photography

NASA Technical Reports Server (NTRS)

Miller, Cearcy D

1946-01-01

A critical review of literature bearing on the autoignition and detonation-wave theories of spark-ignition engine knock and on the nature of gas vibrations associated with combustion and knock results in the conclusion that neither the autoignition theory nor the detonation-wave theory is an adequate explanation of spark-ignition engine knock. A knock theory is proposed, combining the autoignition and detonation-wave theories, which introduces the idea that the detonation wave develops in autoignited or after-burning gases, and ascribes comparatively low-pitched heavy knocks to autoignition but high-pitched pinging knocks to detonation waves with the possibility of combinations of the two types of knocks. Analysis of five shots of knocking combustion, taken with the NACA high-speed motion-picture camera at the rate of 40,000 photographs per second reveals propagation speeds ranging from 3250 to more than 5500 feet per second. The range of propagation speeds from 3250 to more than 5500 feet per second is held to be considered with the proposed combined theory but not with either the simple autoignition theory or the simple detonation-wave theory.

Some research perspectives in galloping phenomena: critical conditions and post-critical behavior

NASA Astrophysics Data System (ADS)

Piccardo, Giuseppe; Pagnini, Luisa Carlotta; Tubino, Federica

2015-01-01

This paper gives an overview of wind-induced galloping phenomena, describing its manifold features and the many advances that have taken place in this field. Starting from a quasi-steady model of aeroelastic forces exerted by the wind on a rigid cylinder with three degree-of-freedom, two translations and a rotation in the plane of the model cross section, the fluid-structure interaction forces are described in simple terms, yet suitable with complexity of mechanical systems, both in the linear and in the nonlinear field, thus allowing investigation of a wide range of structural typologies and their dynamic behavior. The paper is driven by some key concerns. A great effort is made in underlying strengths and weaknesses of the classic quasi-steady theory as well as of the simplistic assumptions that are introduced in order to investigate such complex phenomena through simple engineering models. A second aspect, which is crucial to the authors' approach, is to take into account and harmonize the engineering, physical and mathematical perspectives in an interdisciplinary way—something which does not happen often. The authors underline that the quasi-steady approach is an irreplaceable tool, tough approximate and simple, for performing engineering analyses; at the same time, the study of this phenomenon gives origin to numerous problems that make the application of high-level mathematical solutions particularly attractive. Finally, the paper discusses a wide range of features of the galloping theory and its practical use which deserve further attention and refinements, pointing to the great potential represented by new fields of application and advanced analysis tools.

Quality of anaesthesia-related information accessed via Internet searches.

PubMed

Caron, S; Berton, J; Beydon, L

2007-08-01

We conducted a study to examine the quality and stability of information available from the Internet on four anaesthesia-related topics. In January 2006, we searched using four key words (porphyria, scleroderma, transfusion risk, and epidural analgesia risk) with five search engines (Google, HotBot, AltaVista, Excite, and Yahoo). We used a published scoring system (NetScoring) to evaluate the first 15 sites identified by each of these 20 searches. We also used a simple four-point scale to assess the first 100 sites in the Google search on one of our four topics ('epidural analgesia risk'). In November 2006, we conducted a second evaluation, using three search engines (Google, AltaVista, and Yahoo) with 14 synonyms for 'epidural analgesia risk'. The five search engines performed similarly. NetScoring scores were lower for transfusion risk (P < 0.001). One or more high-quality sites was identified consistently among the first 15 sites in each search. Quality scored using the simple scale correlated closely with medical content and design by NetScoring and with the number of references (P < 0.05). Synonyms of 'epidural analgesia risk' yielded similar results. The quality of accessed information improved somewhat over the 11 month period with Yahoo and AltaVista, but declined with Google. The Internet is a valuable tool for obtaining medical information, but the quality of websites varies between different topics. A simple rating scale may facilitate the quality scoring on individual websites. Differences in precise search terms used for a given topic did not appear to affect the quality of the information obtained.

Measurement of Work Generation and Improvement in Performance of a Pulse Tube Engine

NASA Astrophysics Data System (ADS)

Hamaguchi, Kazuhiro; Futagi, Hiroaki; Yazaki, Taichi; Hiratsuka, Yoshikatsu

Apart from double acting type engines, Stirling engines have either 2 pistons in 2 cylinders or 2 pistons in a single cylinder. Typically, the heater, regenerator and cooler are installed between the 2 pistons. The pulse tube engine, on the other hand, consists of a single piston in a single cylinder, a pulse tube, a heater, a regenerator, a cooler and a second cooler. For this paper, a simple prototype engine that uses air at normal atmospheric pressure as the working gas was fabricated. The oscillating velocity of the working gas in the pulse tube was measured using LDV, and the work flow emitting out of the pulse tube was observed. In addition, the effect of inserting heat storage material in the pulse tube on shaft power and indicated power was examined experimentally. A dramatic increase in the shaft power was achieved.

Accessing Nature’s diversity through metabolic engineering and synthetic biology

PubMed Central

King, Jason R.; Edgar, Steven; Qiao, Kangjian; Stephanopoulos, Gregory

2016-01-01

In this perspective, we highlight recent examples and trends in metabolic engineering and synthetic biology that demonstrate the synthetic potential of enzyme and pathway engineering for natural product discovery. In doing so, we introduce natural paradigms of secondary metabolism whereby simple carbon substrates are combined into complex molecules through “scaffold diversification”, and subsequent “derivatization” of these scaffolds is used to synthesize distinct complex natural products. We provide examples in which modern pathway engineering efforts including combinatorial biosynthesis and biological retrosynthesis can be coupled to directed enzyme evolution and rational enzyme engineering to allow access to the “privileged” chemical space of natural products in industry-proven microbes. Finally, we forecast the potential to produce natural product-like discovery platforms in biological systems that are amenable to single-step discovery, validation, and synthesis for streamlined discovery and production of biologically active agents. PMID:27081481

On the inlet vortex system. [preventing jet engine damage caused by debris pick-up

NASA Technical Reports Server (NTRS)

Bissinger, N. C.; Braun, G. W.

1974-01-01

The flow field of a jet engine with an inlet vortex, which can pick up heavy debris from the ground and damage the engine, was simulated in a small water tunnel by means of the hydrogen bubble technique. It was found that the known engine inlet vortex is accompained by a vortex system, consisting of two inlet vortices (the ground based and the trailing one), secondary vortices, and ground vortices. Simulation of the ground effect by an inlet image proved that the inlet vortex feeds on free stream vorticity and can exist without the presence of a ground boundary layer. The structural form of the inlet vortex system was explained by a simple potential flow model, which showed the number, location, and the importance of the stagnation points. A retractable horizontal screen or an up-tilt of the engine is suggested as countermeasure against debris ingestion.

MD-11 PCA - First Landing at Edwards

NASA Technical Reports Server (NTRS)

1995-01-01

This McDonnell Douglas MD-11 transport aircraft approaches its first landing under engine power only on Aug. 29, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The milestone flight, flown by NASA research pilot and former astronaut Gordon Fullerton, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when its normal control surfaces are disabled. The Propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple--for pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

MD-11 PCA - First Landing at Edwards

NASA Technical Reports Server (NTRS)

1995-01-01

This McDonnell Douglas MD-11 approaches the first landing ever of a transport aircraft under engine power only on Aug. 29, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The milestone flight, flown by NASA research pilot and former astronaut Gordon Fullerton, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when it normal control surfaces are disabled. The Propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple--for pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

Science, Technology, Engineering, Mathematics Poster

NASA Technical Reports Server (NTRS)

Kozusko, Timothy J.

2016-01-01

This is a simple poster for Community Day at the Visitor Center. It describes, as an overview, an example of the use of GPS and LiDAR data to determine the loss of scrubjay habitat due to a change in water table.

Deployed Force Waste Management

DTIC Science & Technology

2004-11-01

Humid Coastal Desert (B3) Cold (C0) (C1) (C2) Severe & Extreme Cold (C3) (C4) Affects effectiveness and efficiency of particular treatment and...surface (eg Spinifex ) Commercially available Easily deployable and some construction by engineers required Simple but specialised

Remote Access Multi-Mission Processing and Analysis Ground Environment (RAMPAGE)

NASA Technical Reports Server (NTRS)

Lee, Y.; Specht, T.

2000-01-01

At Jet Propulsion Laboratory (JPL), a goal of providing easy and simple data access to the mission engineering data using web-based standards to a wide variety of users is now possible by the RAMPAGE development.

A 20-GHz IMPATT transmitter

NASA Technical Reports Server (NTRS)

Chan, J. L.; Sun, C.

1983-01-01

The engineering development of a solid state transmitter amplifier operating in the 20 GHz frequency band. The development effort involved a variety of disciplines including IMPATT device development, circulator design, simple and multiple diode circuits designs, and amplifier integration and test.

Prediction of Petermann I and II Spot Sizes for Single-mode Dispersion-shifted and Dispersion-flattened Fibers by a Simple Technique

NASA Astrophysics Data System (ADS)

Kamila, Kiranmay; Panda, Anup Kumar; Gangopadhyay, Sankar

2013-09-01

Employing the series expression for the fundamental modal field of dispersion-shifted trapezoidal and dispersion-flattened graded and step W fibers, we present simple but accurate analytical expressions for Petermann I and II spot sizes of such kind of fibers. Choosing some typical dispersion-shifted trapezoidal and dispersion-flattened graded and step W fibers as examples, we show that our estimations match excellently with the exact numerical results. The evaluation of the concerned propagation parameters by our formalism needs very little computations. This accurate but simple formalism will benefit the system engineers working in the field of all optical technology.

Applied and engineering versions of the theory of elastoplastic processes of active complex loading part 2: Identification and verification

NASA Astrophysics Data System (ADS)

Peleshko, V. A.

2016-06-01

The deviator constitutive relation of the proposed theory of plasticity has a three-term form (the stress, stress rate, and strain rate vectors formed from the deviators are collinear) and, in the specialized (applied) version, in addition to the simple loading function, contains four dimensionless constants of the material determined from experiments along a two-link strain trajectory with an orthogonal break. The proposed simple mechanism is used to calculate the constants of themodel for four metallic materials that significantly differ in the composition and in the mechanical properties; the obtained constants do not deviate much from their average values (over the four materials). The latter are taken as universal constants in the engineering version of the model, which thus requires only one basic experiment, i. e., a simple loading test. If the material exhibits the strengthening property in cyclic circular deformation, then the model contains an additional constant determined from the experiment along a strain trajectory of this type. (In the engineering version of the model, the cyclic strengthening effect is not taken into account, which imposes a certain upper bound on the difference between the length of the strain trajectory arc and the module of the strain vector.) We present the results of model verification using the experimental data available in the literature about the combined loading along two- and multi-link strain trajectories with various lengths of links and angles of breaks, with plane curvilinear segments of various constant and variable curvature, and with three-dimensional helical segments of various curvature and twist. (All in all, we use more than 80 strain programs; the materials are low- andmedium-carbon steels, brass, and stainless steel.) These results prove that the model can be used to describe the process of arbitrary active (in the sense of nonnegative capacity of the shear) combine loading and final unloading of originally quasi-isotropic elastoplastic materials. In practical calculations, in the absence of experimental data about the properties of a material under combined loading, the use of the engineering version of the model is quite acceptable. The simple identification, wide verifiability, and the availability of a software implementation of the method for solving initial-boundary value problems permit treating the proposed theory as an applied theory.

Knowledge management in the engineering design environment

NASA Technical Reports Server (NTRS)

Briggs, Hugh C.

2006-01-01

The Aerospace and Defense industry is experiencing an increasing loss of knowledge through workforce reductions associated with business consolidation and retirement of senior personnel. Significant effort is being placed on process definition as part of ISO certification and, more recently, CMMI certification. The process knowledge in these efforts represents the simplest of engineering knowledge and many organizations are trying to get senior engineers to write more significant guidelines, best practices and design manuals. A new generation of design software, known as Product Lifecycle Management systems, has many mechanisms for capturing and deploying a wider variety of engineering knowledge than simple process definitions. These hold the promise of significant improvements through reuse of prior designs, codification of practices in workflows, and placement of detailed how-tos at the point of application.

Correlation of Mixture Temperature Data Obtained from Bare Intake-manifold Thermocouples

NASA Technical Reports Server (NTRS)

White, H. Jack; Gammon, Goldie L

1946-01-01

A relatively simple equation has been found to express with fair accuracy, variation in manifold-charge temperature with charge in engine operating conditions. This equation and associated curves have been checked by multi cylinder-engine data, both test stand and flight, over a wide range of operating conditions. Average mixture temperatures, predicted by the equations of this report, agree reasonably well with results within the same range of carburetor-air temperatures from laboratories and test stands other than the NACA.

Engineering topological edge states in two dimensional magnetic photonic crystal

NASA Astrophysics Data System (ADS)

Yang, Bing; Wu, Tong; Zhang, Xiangdong

2017-01-01

Based on a perturbative approach, we propose a simple and efficient method to engineer the topological edge states in two dimensional magnetic photonic crystals. The topological edge states in the microstructures can be constructed and varied by altering the parameters of the microstructure according to the field-energy distributions of the Bloch states at the related Bloch wave vectors. The validity of the proposed method has been demonstrated by exact numerical calculations through three concrete examples. Our method makes the topological edge states "designable."

Cloning Nacre's 3D Interlocking Skeleton in Engineering Composites to Achieve Exceptional Mechanical Properties.

PubMed

Zhao, Hewei; Yue, Yonghai; Guo, Lin; Wu, Juntao; Zhang, Youwei; Li, Xiaodong; Mao, Shengcheng; Han, Xiaodong

2016-07-01

Ceramic/polymer composite equipped with 3D interlocking skeleton (3D IL) is developed through a simple freeze-casting method, exhibiting exceptionally light weight, high strength, toughness, and shock resistance. Long-range crack energy dissipation enabled by 3D interlocking structure is considered as the primary reinforcing mechanism for such superior properties. The smart composite design strategy should hold a place in developing future structural engineering materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficiency of some heat engines at maximum-power conditions

NASA Astrophysics Data System (ADS)

De Vos, Alexis

1985-06-01

In the present paper a simple model is presented for a heat engine, where the power output is limited by the rate of heat supply (and/or heat release). The model leads to a variety of results. Some of them are established laws such as the Carnot law, the Curzon-Ahlborn efficiency, and the Castañs efficiency. Other results are new, and are related to phenomena as different as geothermal energy conversion and the Penfield paradox of electric circuits.

Proceedings of the Regional Seminar on Earthquake Engineering (13th) Held in Istanbul, Turkey on 14-24 September 1987.

DTIC Science & Technology

1987-09-01

Geological Survey, MS977, Menlo Park , CA 94025, USA. , TURKISH NATIONAL COMMITTEE FOR EARTHQUAKE ENGINEERING THIRTEENTH REGIONAL SEMINALR ON EARTQUAKE...this case the conditional probability P(E/F1) will also depend in general on t . A simple example of a case of this type was developed by the present...These studies took Into cosideration all the available date eoncerning the dynamic characteristics of different type * of buildings. A first attempt was

Hybrid Kalman Filter: A New Approach for Aircraft Engine In-Flight Diagnostics

NASA Technical Reports Server (NTRS)

Kobayashi, Takahisa; Simon, Donald L.

2006-01-01

In this paper, a uniquely structured Kalman filter is developed for its application to in-flight diagnostics of aircraft gas turbine engines. The Kalman filter is a hybrid of a nonlinear on-board engine model (OBEM) and piecewise linear models. The utilization of the nonlinear OBEM allows the reference health baseline of the in-flight diagnostic system to be updated to the degraded health condition of the engines through a relatively simple process. Through this health baseline update, the effectiveness of the in-flight diagnostic algorithm can be maintained as the health of the engine degrades over time. Another significant aspect of the hybrid Kalman filter methodology is its capability to take advantage of conventional linear and nonlinear Kalman filter approaches. Based on the hybrid Kalman filter, an in-flight fault detection system is developed, and its diagnostic capability is evaluated in a simulation environment. Through the evaluation, the suitability of the hybrid Kalman filter technique for aircraft engine in-flight diagnostics is demonstrated.

Orbit transfer rocket engine technology program: Automated preflight methods concept definition

NASA Technical Reports Server (NTRS)

Erickson, C. M.; Hertzberg, D. W.

1991-01-01

The possibility of automating preflight engine checkouts on orbit transfer engines is discussed. The minimum requirements in terms of information and processing necessary to assess the engine'e integrity and readiness to perform its mission were first defined. A variety of ways for remotely obtaining that information were generated. The sophistication of these approaches varied from a simple preliminary power up, where the engine is fired up for the first time, to the most advanced approach where the sensor and operational history data system alone indicates engine integrity. The critical issues and benefits of these methods were identified, outlined, and prioritized. The technology readiness of each of these automated preflight methods were then rated on a NASA Office of Exploration scale used for comparing technology options for future mission choices. Finally, estimates were made of the remaining cost to advance the technology for each method to a level where the system validation models have been demonstrated in a simulated environment.

Model-Based Control of an Aircraft Engine using an Optimal Tuner Approach

NASA Technical Reports Server (NTRS)

Connolly, Joseph W.; Chicatelli, Amy; Garg, Sanjay

2012-01-01

This paper covers the development of a model-based engine control (MBEC) method- ology applied to an aircraft turbofan engine. Here, a linear model extracted from the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) at a cruise operating point serves as the engine and the on-board model. The on-board model is up- dated using an optimal tuner Kalman Filter (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. MBEC provides the ability for a tighter control bound of thrust over the entire life cycle of the engine that is not achievable using traditional control feedback, which uses engine pressure ratio or fan speed. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC tighter thrust control. In addition, investigations of using the MBEC to provide a surge limit for the controller limit logic are presented that could provide benefits over a simple acceleration schedule that is currently used in engine control architectures.

Contingency Power Study for Short Haul Civil Tiltrotor

NASA Technical Reports Server (NTRS)

D'Angelo, Marin M.

2004-01-01

NASA has concluded from previous studies that the twin engine tiltrotor is the most economical and technologically viable rotorcraft for near-term civil applications. Twin engine civil rotorcraft must be able to hover safely on one engine in an emergency. This emergency power requirement generally results in engines 20 to 50 percent larger than needed for normal engine operation, negatively impacting aircraft economics. This study identifies several contingency power enhancement concepts, and quantifies their potential to reduce aircraft operating costs. Many unique concepts were examined, and the selected concepts are simple, reliable, and have a high potential for near term realization. These engine concepts allow extremely high turbine temperatures during emergency operation by providing cooling to the power turbine and augmenting cooling of both turbines and structural hardware. Direct operating cost are reduced 3 to percent, which could yield a 30 to 80 percent increase in operating profits. The study consists of the definition of an aircraft economics model and a baseline engine, and an engine concept screening study, and a preliminary definition of the selected concepts. The selected concepts are evaluated against the baseline engine, and the critical technologies and development needs are identified, along with applications for this technology.

Comparing convective heat fluxes derived from thermodynamics to a radiative-convective model and GCMs

NASA Astrophysics Data System (ADS)

Dhara, Chirag; Renner, Maik; Kleidon, Axel

2015-04-01

The convective transport of heat and moisture plays a key role in the climate system, but the transport is typically parameterized in models. Here, we aim at the simplest possible physical representation and treat convective heat fluxes as the result of a heat engine. We combine the well-known Carnot limit of this heat engine with the energy balances of the surface-atmosphere system that describe how the temperature difference is affected by convective heat transport, yielding a maximum power limit of convection. This results in a simple analytic expression for convective strength that depends primarily on surface solar absorption. We compare this expression with an idealized grey atmosphere radiative-convective (RC) model as well as Global Circulation Model (GCM) simulations at the grid scale. We find that our simple expression as well as the RC model can explain much of the geographic variation of the GCM output, resulting in strong linear correlations among the three approaches. The RC model, however, shows a lower bias than our simple expression. We identify the use of the prescribed convective adjustment in RC-like models as the reason for the lower bias. The strength of our model lies in its ability to capture the geographic variation of convective strength with a parameter-free expression. On the other hand, the comparison with the RC model indicates a method for improving the formulation of radiative transfer in our simple approach. We also find that the latent heat fluxes compare very well among the approaches, as well as their sensitivity to surface warming. What our comparison suggests is that the strength of convection and their sensitivity in the climatic mean can be estimated relatively robustly by rather simple approaches.

Use of Mesothelial Cells and Biological Matrices for Tissue Engineering of Simple Epithelium Surrogates.

PubMed

Lachaud, Christian Claude; Rodriguez-Campins, Berta; Hmadcha, Abdelkrim; Soria, Bernat

2015-01-01

Tissue-engineering technologies have progressed rapidly through last decades resulting in the manufacture of quite complex bioartificial tissues with potential use for human organ and tissue regeneration. The manufacture of avascular monolayered tissues such as simple squamous epithelia was initiated a few decades ago and is attracting increasing interest. Their relative morphostructural simplicity makes of their biomimetization a goal, which is currently accessible. The mesothelium is a simple squamous epithelium in nature and is the monolayered tissue lining the walls of large celomic cavities (peritoneal, pericardial, and pleural) and internal organs housed inside. Interestingly, mesothelial cells can be harvested in clinically relevant numbers from several anatomical sources and not less important, they also display high transdifferentiation capacities and are low immunogenic characteristics, which endow these cells with therapeutic interest. Their combination with a suitable scaffold (biocompatible, degradable, and non-immunogenic) may allow the manufacture of tailored serosal membranes biomimetics with potential spanning a wide range of therapeutic applications, principally for the regeneration of simple squamous-like epithelia such as the visceral and parietal mesothelium vascular endothelium and corneal endothelium among others. Herein, we review recent research progresses in mesothelial cells biology and their clinical sources. We make a particular emphasis on reviewing the different types of biological scaffolds suitable for the manufacture of serosal mesothelial membranes biomimetics. Finally, we also review progresses made in mesothelial cells-based therapeutic applications and propose some possible future directions.

Use of Mesothelial Cells and Biological Matrices for Tissue Engineering of Simple Epithelium Surrogates

PubMed Central

Lachaud, Christian Claude; Rodriguez-Campins, Berta; Hmadcha, Abdelkrim; Soria, Bernat

2015-01-01

Tissue-engineering technologies have progressed rapidly through last decades resulting in the manufacture of quite complex bioartificial tissues with potential use for human organ and tissue regeneration. The manufacture of avascular monolayered tissues such as simple squamous epithelia was initiated a few decades ago and is attracting increasing interest. Their relative morphostructural simplicity makes of their biomimetization a goal, which is currently accessible. The mesothelium is a simple squamous epithelium in nature and is the monolayered tissue lining the walls of large celomic cavities (peritoneal, pericardial, and pleural) and internal organs housed inside. Interestingly, mesothelial cells can be harvested in clinically relevant numbers from several anatomical sources and not less important, they also display high transdifferentiation capacities and are low immunogenic characteristics, which endow these cells with therapeutic interest. Their combination with a suitable scaffold (biocompatible, degradable, and non-immunogenic) may allow the manufacture of tailored serosal membranes biomimetics with potential spanning a wide range of therapeutic applications, principally for the regeneration of simple squamous-like epithelia such as the visceral and parietal mesothelium vascular endothelium and corneal endothelium among others. Herein, we review recent research progresses in mesothelial cells biology and their clinical sources. We make a particular emphasis on reviewing the different types of biological scaffolds suitable for the manufacture of serosal mesothelial membranes biomimetics. Finally, we also review progresses made in mesothelial cells-based therapeutic applications and propose some possible future directions. PMID:26347862

Optical spectroscopy of arrays of Ag-Au nanoparticles obtained by vacuum-thermal evaporation

NASA Astrophysics Data System (ADS)

Gromov, D. G.; Mel'nikov, I. V.; Savitskii, A. I.; Trifonov, A. Yu.; Redichev, E. N.; Astapenko, V. A.

2017-03-01

The possibility of creating irregular arrays of bimetallic Ag-Au nanoparticles is investigated. The ability to manipulate their optical properties based on the simple engineering processes of thermal spraying followed by low-temperature annealing is demonstrated.

Robust Strategy for Rocket Engine Health Monitoring

NASA Technical Reports Server (NTRS)

Santi, L. Michael

2001-01-01

Monitoring the health of rocket engine systems is essentially a two-phase process. The acquisition phase involves sensing physical conditions at selected locations, converting physical inputs to electrical signals, conditioning the signals as appropriate to establish scale or filter interference, and recording results in a form that is easy to interpret. The inference phase involves analysis of results from the acquisition phase, comparison of analysis results to established health measures, and assessment of health indications. A variety of analytical tools may be employed in the inference phase of health monitoring. These tools can be separated into three broad categories: statistical, rule based, and model based. Statistical methods can provide excellent comparative measures of engine operating health. They require well-characterized data from an ensemble of "typical" engines, or "golden" data from a specific test assumed to define the operating norm in order to establish reliable comparative measures. Statistical methods are generally suitable for real-time health monitoring because they do not deal with the physical complexities of engine operation. The utility of statistical methods in rocket engine health monitoring is hindered by practical limits on the quantity and quality of available data. This is due to the difficulty and high cost of data acquisition, the limited number of available test engines, and the problem of simulating flight conditions in ground test facilities. In addition, statistical methods incur a penalty for disregarding flow complexity and are therefore limited in their ability to define performance shift causality. Rule based methods infer the health state of the engine system based on comparison of individual measurements or combinations of measurements with defined health norms or rules. This does not mean that rule based methods are necessarily simple. Although binary yes-no health assessment can sometimes be established by relatively simple rules, the causality assignment needed for refined health monitoring often requires an exceptionally complex rule base involving complicated logical maps. Structuring the rule system to be clear and unambiguous can be difficult, and the expert input required to maintain a large logic network and associated rule base can be prohibitive.

Model-Based Control of a Nonlinear Aircraft Engine Simulation using an Optimal Tuner Kalman Filter Approach

NASA Technical Reports Server (NTRS)

Connolly, Joseph W.; Csank, Jeffrey Thomas; Chicatelli, Amy; Kilver, Jacob

2013-01-01

This paper covers the development of a model-based engine control (MBEC) methodology featuring a self tuning on-board model applied to an aircraft turbofan engine simulation. Here, the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) serves as the MBEC application engine. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC over a wide range of operating points. The on-board model is a piece-wise linear model derived from CMAPSS40k and updated using an optimal tuner Kalman Filter (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. Investigations using the MBEC to provide a stall margin limit for the controller protection logic are presented that could provide benefits over a simple acceleration schedule that is currently used in traditional engine control architectures.

Atomic force microscopy reveals the mechanical design of a modular protein

PubMed Central

Li, Hongbin; Oberhauser, Andres F.; Fowler, Susan B.; Clarke, Jane; Fernandez, Julio M.

2000-01-01

Tandem modular proteins underlie the elasticity of natural adhesives, cell adhesion proteins, and muscle proteins. The fundamental unit of elastic proteins is their individually folded modules. Here, we use protein engineering to construct multimodular proteins composed of Ig modules of different mechanical strength. We examine the mechanical properties of the resulting tandem modular proteins by using single protein atomic force microscopy. We show that by combining modules of known mechanical strength, we can generate proteins with novel elastic properties. Our experiments reveal the simple mechanical design of modular proteins and open the way for the engineering of elastic proteins with defined mechanical properties, which can be used in tissue and fiber engineering. PMID:10823913

Atomic force microscopy reveals the mechanical design of a modular protein.

PubMed

Li, H; Oberhauser, A F; Fowler, S B; Clarke, J; Fernandez, J M

2000-06-06

Tandem modular proteins underlie the elasticity of natural adhesives, cell adhesion proteins, and muscle proteins. The fundamental unit of elastic proteins is their individually folded modules. Here, we use protein engineering to construct multimodular proteins composed of Ig modules of different mechanical strength. We examine the mechanical properties of the resulting tandem modular proteins by using single protein atomic force microscopy. We show that by combining modules of known mechanical strength, we can generate proteins with novel elastic properties. Our experiments reveal the simple mechanical design of modular proteins and open the way for the engineering of elastic proteins with defined mechanical properties, which can be used in tissue and fiber engineering.

Engineered Escherichia coli Silver-Binding Periplasmic Protein That Promotes Silver Tolerance

PubMed Central

Hall Sedlak, Ruth; Hnilova, Marketa; Grosh, Carolynn; Fong, Hanson; Baneyx, Francois; Schwartz, Dan; Sarikaya, Mehmet; Tamerler, Candan

2012-01-01

Silver toxicity is a problem that microorganisms face in medical and environmental settings. Through exposure to silver compounds, some bacteria have adapted to growth in high concentrations of silver ions. Such adapted microbes may be dangerous as pathogens but, alternatively, could be potentially useful in nanomaterial-manufacturing applications. While naturally adapted isolates typically utilize efflux pumps to achieve metal resistance, we have engineered a silver-tolerant Escherichia coli strain by the use of a simple silver-binding peptide motif. A silver-binding peptide, AgBP2, was identified from a combinatorial display library and fused to the C terminus of the E. coli maltose-binding protein (MBP) to yield a silver-binding protein exhibiting nanomolar affinity for the metal. Growth experiments performed in the presence of silver nitrate showed that cells secreting MBP-AgBP2 into the periplasm exhibited silver tolerance in a batch culture, while those expressing a cytoplasmic version of the fusion protein or MBP alone did not. Transmission electron microscopy analysis of silver-tolerant cells revealed the presence of electron-dense silver nanoparticles. This is the first report of a specifically engineered metal-binding peptide exhibiting a strong in vivo phenotype, pointing toward a novel ability to manipulate bacterial interactions with heavy metals by the use of short and simple peptide motifs. Engineered metal-ion-tolerant microorganisms such as this E. coli strain could potentially be used in applications ranging from remediation to interrogation of biomolecule-metal interactions in vivo. PMID:22286990

A global model for steady state and transient S.I. engine heat transfer studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohac, S.V.; Assanis, D.N.; Baker, D.M.

1996-09-01

A global, systems-level model which characterizes the thermal behavior of internal combustion engines is described in this paper. Based on resistor-capacitor thermal networks, either steady-state or transient thermal simulations can be performed. A two-zone, quasi-dimensional spark-ignition engine simulation is used to determine in-cylinder gas temperature and convection coefficients. Engine heat fluxes and component temperatures can subsequently be predicted from specification of general engine dimensions, materials, and operating conditions. Emphasis has been placed on minimizing the number of model inputs and keeping them as simple as possible to make the model practical and useful as an early design tool. The successmore » of the global model depends on properly scaling the general engine inputs to accurately model engine heat flow paths across families of engine designs. The development and validation of suitable, scalable submodels is described in detail in this paper. Simulation sub-models and overall system predictions are validated with data from two spark ignition engines. Several sensitivity studies are performed to determine the most significant heat transfer paths within the engine and exhaust system. Overall, it has been shown that the model is a powerful tool in predicting steady-state heat rejection and component temperatures, as well as transient component temperatures.« less

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

NASA Astrophysics Data System (ADS)

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.

Towards organ printing: engineering an intra-organ branched vascular tree

PubMed Central

Visconti, Richard P; Kasyanov, Vladimir; Gentile, Carmine; Zhang, Jing; Markwald, Roger R; Mironov, Vladimir

2013-01-01

Importance of the field Effective vascularization of thick three-dimensional engineered tissue constructs is a problem in tissue engineering. As in native organs, a tissue-engineered intra-organ vascular tree must be comprised of a network of hierarchically branched vascular segments. Despite this requirement, current tissue-engineering efforts are still focused predominantly on engineering either large-diameter macrovessels or microvascular networks. Areas covered in this review We present the emerging concept of organ printing or robotic additive biofabrication of an intra-organ branched vascular tree, based on the ability of vascular tissue spheroids to undergo self-assembly. What the reader will gain The feasibility and challenges of this robotic biofabrication approach to intra-organ vascularization for tissue engineering based on organ-printing technology using self-assembling vascular tissue spheroids including clinically relevantly vascular cell sources are analyzed. Take home message It is not possible to engineer 3D thick tissue or organ constructs without effective vascularization. An effective intra-organ vascular system cannot be built by the simple connection of large-diameter vessels and microvessels. Successful engineering of functional human organs suitable for surgical implantation will require concomitant engineering of a ‘built in’ intra-organ branched vascular system. Organ printing enables biofabrication of human organ constructs with a ‘built in’ intra-organ branched vascular tree. PMID:20132061

A Stirling engine for use with lower quality fuels

NASA Astrophysics Data System (ADS)

Paul, Christopher J.

There is increasing interest in using renewable fuels from biomass or alternative fuels such as municipal waste to reduce the need for fossil based fuels. Due to the lower heating values and higher levels of impurities, small scale electricity generation is more problematic. Currently, there are not many technologically mature options for small scale electricity generation using lower quality fuels. Even though there are few manufacturers of Stirling engines, the history of their development for two centuries offers significant guidance in developing a viable small scale generator set using lower quality fuels. The history, development, and modeling of Stirling engines were reviewed to identify possible model and engine configurations. A Stirling engine model based on the finite volume, ideal adiabatic model was developed. Flow dissipation losses are shown to need correcting as they increase significantly at low mean engine pressure and high engine speed. The complete engine including external components was developed. A simple yet effective method of evaluating the external heat transfer to the Stirling engine was created that can be used with any second order Stirling engine model. A derivative of the General Motors Ground Power Unit 3 was designed. By significantly increasing heater, cooler and regenerator size at the expense of increased dead volume, and adding a combustion gas recirculation, a generator set with good efficiency was designed.

Modeling the lung: Design and development of tissue engineered macro- and micro-physiologic lung models for research use.

PubMed

Nichols, Joan E; Niles, Jean A; Vega, Stephanie P; Argueta, Lissenya B; Eastaway, Adriene; Cortiella, Joaquin

2014-09-01

Respiratory tract specific cell populations, or tissue engineered in vitro grown human lung, have the potential to be used as research tools to mimic physiology, toxicology, pathology, as well as infectious diseases responses of cells or tissues. Studies related to respiratory tract pathogenesis or drug toxicity testing in the past made use of basic systems where single cell populations were exposed to test agents followed by evaluations of simple cellular responses. Although these simple single-cell-type systems provided good basic information related to cellular responses, much more can be learned from cells grown in fabricated microenvironments which mimic in vivo conditions in specialized microfabricated chambers or by human tissue engineered three-dimensional (3D) models which allow for more natural interactions between cells. Recent advances in microengineering technology, microfluidics, and tissue engineering have provided a new approach to the development of 2D and 3D cell culture models which enable production of more robust human in vitro respiratory tract models. Complex models containing multiple cell phenotypes also provide a more reasonable approximation of what occurs in vivo without the confounding elements in the dynamic in vivo environment. The goal of engineering good 3D human models is the formation of physiologically functional respiratory tissue surrogates which can be used as pathogenesis models or in the case of 2D screening systems for drug therapy evaluation as well as human toxicity testing. We hope that this manuscript will serve as a guide for development of future respiratory tract model systems as well as a review of conventional models. © 2014 by the Society for Experimental Biology and Medicine.

Reed Valve Regulates Welding Back-Purge Pressure

NASA Technical Reports Server (NTRS)

Coby, J. Ben, Jr.; Weeks, Jack L.

1991-01-01

Simple modification yields welds of better quality. Reed valve halves fluctuations in pressure in back-purge chamber attached to workpiece undergoing keyhole plasma arc welding. Identical to one used in fuel system of two-cycle gasoline engine. Backbead smoother, and weld penetrates more uniformly.

Search and Rescue!

ERIC Educational Resources Information Center

Sharland, Hannah

2011-01-01

The author believes that to truly engage children in learning, an imaginative approach with purposeful activities is very important. One way that this can be implemented is through simple "engineering projects" where science, design and technology (D&T), mathematics and information and communication technology (ICT) are combined,…

Structural Reliability and Monte Carlo Simulation.

ERIC Educational Resources Information Center

Laumakis, P. J.; Harlow, G.

2002-01-01

Analyzes a simple boom structure and assesses its reliability using elementary engineering mechanics. Demonstrates the power and utility of Monte-Carlo simulation by showing that such a simulation can be implemented more readily with results that compare favorably to the theoretical calculations. (Author/MM)

Fast determination of soil behavior in the capillary zone using simple laboratory tests.

DOT National Transportation Integrated Search

2012-12-01

Frost heave and thaw weakening are typical problems for engineers building in northern regions. These unsaturated-soil behaviors are : caused by water flowing through the capillary zone to a freezing front, where it forms ice lenses. Although suction...

A Simple Explanation of Complexation

ERIC Educational Resources Information Center

Elliott, J. Richard

2010-01-01

The topics of solution thermodynamics, activity coefficients, and complex formation are introduced through computational exercises and sample applications. The presentation is designed to be accessible to freshmen in a chemical engineering computations course. The MOSCED model is simplified to explain complex formation in terms of hydrogen…

Cooperative Multi-Agent Mobile Sensor Platforms for Jet Engine Inspection: Concept and Implementation

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Wong, Edmond; Krasowski, Michael J.; Greer, Lawrence C.

2003-01-01

Cooperative behavior algorithms utilizing swarm intelligence are being developed for mobile sensor platforms to inspect jet engines on-wing. Experiments are planned in which several relatively simple autonomous platforms will work together in a coordinated fashion to carry out complex maintenance-type tasks within the constrained working environment modeled on the interior of a turbofan engine. The algorithms will emphasize distribution of the tasks among multiple units; they will be scalable and flexible so that units may be added in the future; and will be designed to operate on an individual unit level to produce the desired global effect. This proof of concept demonstration will validate the algorithms and provide justification for further miniaturization and specialization of the hardware toward the true application of on-wing in situ turbine engine maintenance.

Engineering approximations in welding: Bridging the gap between the speculation and simulation

DOE PAGES

Robino, Charles V.

2016-01-15

During the course of their careers, welding engineers and welding metallurgists are often confronted with questions regarding welding process and properties that on the surface appear to be simple and direct, but are in fact quite challenging. These questions generally mask an underlying complexity whose underpinnings in scientific and applied research predate even the founding of the American Welding Society, and previous Comfort A. Adams lectures provide ample and fascinating evidence of the breadth and depth of this complexity. Using these studies or their own experiences and investigations as a basis, most welding and materials engineers have developed engineering toolsmore » to provide working approaches to these day-to-day questions and problems. In this article several examples of research into developing working approaches to welding problems are presented.« less

An engineering approach to modelling, decision support and control for sustainable systems.

PubMed

Day, W; Audsley, E; Frost, A R

2008-02-12

Engineering research and development contributes to the advance of sustainable agriculture both through innovative methods to manage and control processes, and through quantitative understanding of the operation of practical agricultural systems using decision models. This paper describes how an engineering approach, drawing on mathematical models of systems and processes, contributes new methods that support decision making at all levels from strategy and planning to tactics and real-time control. The ability to describe the system or process by a simple and robust mathematical model is critical, and the outputs range from guidance to policy makers on strategic decisions relating to land use, through intelligent decision support to farmers and on to real-time engineering control of specific processes. Precision in decision making leads to decreased use of inputs, less environmental emissions and enhanced profitability-all essential to sustainable systems.

Identifying and engineering promoters for high level and sustainable therapeutic recombinant protein production in cultured mammalian cells.

PubMed

Ho, Steven C L; Yang, Yuansheng

2014-08-01

Promoters are essential on plasmid vectors to initiate transcription of the transgenes when generating therapeutic recombinant proteins expressing mammalian cell lines. High and sustained levels of gene expression are desired during therapeutic protein production while gene expression is useful for cell engineering. As many finely controlled promoters exhibit cell and product specificity, new promoters need to be identified, optimized and carefully evaluated before use. Suitable promoters can be identified using techniques ranging from simple molecular biology methods to modern high-throughput omics screenings. Promoter engineering is often required after identification to either obtain high and sustained expression or to provide a wider range of gene expression. This review discusses some of the available methods to identify and engineer promoters for therapeutic recombinant protein expression in mammalian cells.

Engineering approximations in welding: Bridging the gap between the speculation and simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robino, Charles V.

During the course of their careers, welding engineers and welding metallurgists are often confronted with questions regarding welding process and properties that on the surface appear to be simple and direct, but are in fact quite challenging. These questions generally mask an underlying complexity whose underpinnings in scientific and applied research predate even the founding of the American Welding Society, and previous Comfort A. Adams lectures provide ample and fascinating evidence of the breadth and depth of this complexity. Using these studies or their own experiences and investigations as a basis, most welding and materials engineers have developed engineering toolsmore » to provide working approaches to these day-to-day questions and problems. In this article several examples of research into developing working approaches to welding problems are presented.« less

Optimization in the systems engineering process

NASA Technical Reports Server (NTRS)

Lemmerman, Loren A.

1993-01-01

The essential elements of the design process consist of the mission definition phase that provides the system requirements, the conceptual design, the preliminary design and finally the detailed design. Mission definition is performed largely by operations analysts in conjunction with the customer. The result of their study is handed off to the systems engineers for documentation as the systems requirements. The document that provides these requirements is the basis for the further design work of the design engineers at the Lockheed-Georgia Company. The design phase actually begins with conceptual design, which is generally conducted by a small group of engineers using multidisciplinary design programs. Because of the complexity of the design problem, the analyses are relatively simple and generally dependent on parametric analyses of the configuration. The result of this phase is a baseline configuration from which preliminary design may be initiated.

Engine spectrometer probe and method of use

NASA Technical Reports Server (NTRS)

Barkhoudarian, Sarkis (Inventor); Kittinger, Scott A. (Inventor)

2006-01-01

The engine spectrometer probe and method of using the same of the present invention provides a simple engine spectrometer probe which is both lightweight and rugged, allowing an exhaust plume monitoring system to be attached to a vehicle, such as the space shuttle. The engine spectrometer probe can be mounted to limit exposure to the heat and debris of the exhaust plume. The spectrometer probe 50 comprises a housing 52 having an aperture 55 and a fiber optic cable 60 having a fiber optic tip 65. The fiber optic tip 65 has an acceptance angle 87 and is coupled to the aperture 55 so that the acceptance angle 87 intersects the exhaust plume 30. The spectrometer probe can generate a spectrum signal from light in the acceptance angle 506 and the spectrum signal can be provided to a spectrometer 508.

Simple Chaotic Flow with Circle and Square Equilibrium

NASA Astrophysics Data System (ADS)

Gotthans, Tomas; Sprott, Julien Clinton; Petrzela, Jiri

Simple systems of third-order autonomous nonlinear differential equations can exhibit chaotic behavior. In this paper, we present a new class of chaotic flow with a square-shaped equilibrium. This unique property has apparently not yet been described. Such a system belongs to a newly introduced category of chaotic systems with hidden attractors that are interesting and important in engineering applications. The mathematical model is accompanied by an electrical circuit implementation, demonstrating structural stability of the strange attractor. The circuit is simulated with PSpice, constructed, and analyzed (measured).

Perspectives in metabolic engineering: understanding cellular regulation towards the control of metabolic routes.

PubMed

Zadran, Sohila; Levine, Raphael D

2013-01-01

Metabolic engineering seeks to redirect metabolic pathways through the modification of specific biochemical reactions or the introduction of new ones with the use of recombinant technology. Many of the chemicals synthesized via introduction of product-specific enzymes or the reconstruction of entire metabolic pathways into engineered hosts that can sustain production and can synthesize high yields of the desired product as yields of natural product-derived compounds are frequently low, and chemical processes can be both energy and material expensive; current endeavors have focused on using biologically derived processes as alternatives to chemical synthesis. Such economically favorable manufacturing processes pursue goals related to sustainable development and "green chemistry". Metabolic engineering is a multidisciplinary approach, involving chemical engineering, molecular biology, biochemistry, and analytical chemistry. Recent advances in molecular biology, genome-scale models, theoretical understanding, and kinetic modeling has increased interest in using metabolic engineering to redirect metabolic fluxes for industrial and therapeutic purposes. The use of metabolic engineering has increased the productivity of industrially pertinent small molecules, alcohol-based biofuels, and biodiesel. Here, we highlight developments in the practical and theoretical strategies and technologies available for the metabolic engineering of simple systems and address current limitations.

Phase-exchange thermoacoustic engine

NASA Astrophysics Data System (ADS)

Offner, Avshalom; Meir, Avishai; Ramon, Guy Z.; WET Lab Team

2017-11-01

Phase-exchange thermoacoustic engines are reliable machines holding great promise in converting heat from low grade heat sources to mechanical or electrical power. In these engines the working fluid is a gas mixture containing one condensable component, decreasing the temperature difference required for ignition and steady state operation. Our experimental setup consists of a vertical acoustic resonator containing a mixture of air-water vapor. Water evaporates near the heat source, condenses at the heat sink and is drawn back down by gravity and capillary forces where it re-evaporates, sustaining a steady state closed thermodynamic cycle. We investigated the stability limit, namely the critical point at which temperature difference in the engine enables onset of self-excited oscillations, and the steady state of the engine. A simple theoretical model was derived, describing mechanisms of irreversible entropy generation and production of acoustic power in such engines. This model captures the essence in the differences between regular and phase-exchange thermoacoustic engines, and shows good agreement with experimental results of stability limit. Steady state results reveal not only a dramatic decrease in temperature difference, but also an increase in engine performances. The authors acknowledge the support from the Nancy and Stephen Grand Technion Energy Program (GTEP).

Introducing a new semi-active engine mount using force controlled variable stiffness

NASA Astrophysics Data System (ADS)

Azadi, Mojtaba; Behzadipour, Saeed; Faulkner, Gary

2013-05-01

This work introduces a new concept in designing semi-active engine mounts. Engine mounts are under continuous development to provide better and more cost-effective engine vibration control. Passive engine mounts do not provide satisfactory solution. Available semi-active and active mounts provide better solutions but they are more complex and expensive. The variable stiffness engine mount (VSEM) is a semi-active engine mount with a simple ON-OFF control strategy. However, unlike available semi-active engine mounts that work based on damping change, the VSEM works based on the static stiffness change by using a new fast response force controlled variable spring. The VSEM is an improved version of the vibration mount introduced by the authors in their previous work. The results showed significant performance improvements over a passive rubber mount. The VSEM also provides better vibration control than a hydromount at idle speed. Low hysteresis and the ability to be modelled by a linear model in low-frequency are the advantages of the VSEM over the vibration isolator introduced earlier and available hydromounts. These specifications facilitate the use of VSEM in the automotive industry, however, further evaluation and developments are needed for this purpose.

Engineering N-Glycosylation Pathway in Insect Cells: Suppression of β-N-Acetylglucosaminidase and Expression of β-1,4-Galactosyltransferase.

PubMed

Kim, Yeon Kyu; Cha, Hyung Joon

2015-01-01

Most insect cells have a simple N-glycosylation process and consequently paucimannosidic or simple core glycans predominate. It has been proposed that β-N-acetylglucosaminidase (GlcNAcase), a hexosaminidase in the Golgi membrane which removes a terminal N-acetylglucosamine (GlcNAc), might contribute to simple N-glycosylation profile in several insect cells including Drosophila S2. Here, we describe GlcNAcase suppression strategy using RNA interference (RNAi) to avoid the formation of paucimannosidic glycans in insect S2 cells. In addition, we describe coexpression of β(1,4)-galactosyltransferase (GalT) as a strategy to improve N-glycosylation pattern and enable recombinant therapeutic proteins to be produced in S2 cells with more complex N-glycans.

Cyclic axial-torsional deformation behavior of a cobalt-base superalloy

NASA Technical Reports Server (NTRS)

Bonacuse, Peter J.; Kalluri, Sreeramesh

1992-01-01

Multiaxial loading, especially at elevated temperature, can cause the inelastic response of a material to differ significantly from that predicted by simple flow rules, i.e., von Mises or Tresca. To quantify some of these differences, the cyclic high-temperature, deformation behavior of a wrought cobalt-based superalloy, Haynes 188, is investigated under combined axial and torsional loads. Haynes 188 is currently used in many aerospace gas turbine and rocket engine applications, e.g., the combustor liner for the T800 turboshaft engine for the RAH-66 Comanche helicopter and the liquid oxygen posts in the main injector of the space shuttle main engine. The deformation behavior of this material is assessed through the examination of hysteresis loops generated from a biaxial fatigue test program. A high-temperature axial, torsional, and combined axial-torsional fatigue data base has been generated on Haynes 188 at 760 C. Cyclic loading tests have been conducted on uniform gauge section tubular specimens in a servohydraulic axial-torsional test rig. Test control and data acquisition were accomplished with a minicomputer. In this paper, the cyclic hardening characteristics and typical hysteresis loops in the axial stress versus axial strain, shear stress versus engineering shear strain, axial strain versus engineering shear strain, and axial stress versus shear stress spaces are presented for cyclic, in-phase and out-of-phase, axial torsional tests. For in-phase tests three different values of the proportionality constant, lambda (ratio of engineering shear strain amplitude to axial strain amplitude), are examined, viz., 0.86, 1.73, and 3.46. In the out-of-phase tests, three different values of the phase angle, phi (between the axial and engineering shear strain waveforms), are studied, viz., 30, 60, and 90 deg with lambda = 1.73. The cyclic hardening behaviors of all the tests conducted on Haynes 188 at 760 C are evaluated using the von Mises equivalent stress-strain and the maximum shear stress-maximum engineering shear strain (Tresca) curves. Comparisons are also made between the hardening behaviors of cyclic axial, torsional, and combined in-phase and out-of-phase axial-torsional fatigue tests. These comparisons are accomplished through simple Ramberg-Osgood type stress-strain functions for cyclic, axial stress-strain and shear stress-engineering shear strain curves.

Examination of the collision force method for analyzing the responses of simple containment/deflection structures to impact by one engine rotor blade fragment

NASA Technical Reports Server (NTRS)

Zirin, R. M.; Witmer, E. A.

1972-01-01

An approximate collision analysis, termed the collision-force method, was developed for studying impact-interaction of an engine rotor blade fragment with an initially circular containment ring. This collision analysis utilizes basic mass, material property, geometry, and pre-impact velocity information for the fragment, together with any one of three postulated patterns of blade deformation behavior: (1) the elastic straight blade model, (2) the elastic-plastic straight shortening blade model, and (3) the elastic-plastic curling blade model. The collision-induced forces are used to predict the resulting motions of both the blade fragment and the containment ring. Containment ring transient responses are predicted by a finite element computer code which accommodates the large deformation, elastic-plastic planar deformation behavior of simple structures such as beams and/or rings. The effects of varying the values of certain parameters in each blade-behavior model were studied. Comparisons of predictions with experimental data indicate that of the three postulated blade-behavior models, the elastic-plastic curling blade model appears to be the most plausible and satisfactory for predicting the impact-induced motions of a ductile engine rotor blade and a containment ring against which the blade impacts.

Metadata: Pure and Simple, or Is It?

ERIC Educational Resources Information Center

Chalmers, Marilyn

2002-01-01

Discusses issues concerning metadata in Web pages based on experiences in a vocational education center library in Queensland (Australia). Highlights include Dublin Core elements; search engines; controlled vocabulary; performance measurement to assess usage patterns and provide quality control over the vocabulary; and considerations given the…

Phthalocyanine Blends Improve Bulk Heterojunction Solar Cells

PubMed Central

Varotto, Alessandro; Nam, Chang-Yong; Radivojevic, Ivana; Tomé, Joao; Cavaleiro, José A.S.; Black, Charles T.; Drain, Charles Michael

2010-01-01

A core phthalocyanine platform allows engineering the solubility properties the band gap; shifting the maximum absorption toward the red. A simple method to increase the efficiency of heterojunction solar cells uses a self-organized blend of the phthalocyanine chromophores fabricated by solution processing. PMID:20136126

Traffic Flow Estimates.

ERIC Educational Resources Information Center

Hart, Vincent G.

1981-01-01

Two examples are given of ways traffic engineers estimate traffic flow. The first, Floating Car Method, involves some basic ideas and the notion of relative velocity. The second, Maximum Traffic Flow, is viewed to involve simple applications of calculus. The material provides insight into specialized applications of mathematics. (MP)

Prediction of channel degradation rates in urbanizing watersheds

USDA-ARS?s Scientific Manuscript database

In urbanizing watersheds, as land use changes, and storm sewers and impervious surfaces are increased, both the frequency and magnitude of discharge increase, resulting in stream channel down-cutting and widening and related loss of structures and engineering works. A simple model for assessing the ...

Modeling an explosion : the devil is in the details

Treesearch

Peter W. Hart; Alan W. Rudie

2011-01-01

The Chemical Safety and Hazards Investigation Board has recently encouraged chemical engineering faculty to address student knowledge about reactive hazards in their curricula. This paper presents a simple approach that may be used to illustrate the importance of these types of safety considerations.

Assessing Environmental Impacts of Biofuels using Life-Cycle-Based Approaches

EPA Science Inventory

There is no simple answer to the question “are materials and products that are made from biofeedstocks environmentally sustainable?” However, thinking holistically allows decision-makers to view the potential ‘cradle-to-grave’ environmental impacts of the engineered systems that ...

Development of a TL-3 deep beam tubular backup bridge rail : executive summary report.

DOT National Transportation Integrated Search

2010-12-01

Ohio Department of Transportation (ODOT)s Office of Structural Engineering has a need to evaluate and, if necessary, improve an existing bridge rail design with a simple retrofitting procedure to meet current or proposed crash testing standards. T...

Sound radiation from a flanged inclined duct.

PubMed

McAlpine, Alan; Daymond-King, Alex P; Kempton, Andrew J

2012-12-01

A simple method to calculate sound radiation from a flanged inclined duct is presented. An inclined annular duct is terminated by a rigid vertical plane. The duct termination is representative of a scarfed exit. The concept of a scarfed duct has been examined in turbofan aero-engines as a means to, potentially, shield a portion of the radiated sound from being transmitted directly to the ground. The sound field inside the annular duct is expressed in terms of spinning modes. Exterior to the duct, the radiated sound field owing to each mode can be expressed in terms of its directivity pattern, which is found by evaluating an appropriate form of Rayleigh's integral. The asymmetry is shown to affect the amplitude of the principal lobe of the directivity pattern, and to alter the proportion of the sound power radiated up or down. The methodology detailed in this article provides a simple engineering approach to investigate the sound radiation for a three-dimensional problem.

Pilot-in-the-Loop Analysis of Propulsive-Only Flight Control Systems

NASA Technical Reports Server (NTRS)

Chou, Hwei-Lan; Biezad, Daniel J.

1996-01-01

Longitudinal control system architectures are presented which directly couple flight stick motions to throttle commands for a multi-engine aircraft. This coupling enables positive attitude control with complete failure of the flight control system. The architectures chosen vary from simple feedback gains to classical lead-lag compensators with and without prefilters. Each architecture is reviewed for its appropriateness for piloted flight. The control systems are then analyzed with pilot-in-the-loop metrics related to bandwidth required for landing. Results indicate that current and proposed bandwidth requirements should be modified for throttles only flight control. Pilot ratings consistently showed better ratings than predicted by analysis. Recommendations are made for more robust design and implementation. The use of Quantitative Feedback Theory for compensator design is discussed. Although simple and effective augmented control can be achieved in a wide variety of failed configurations, a few configuration characteristics are dominant for pilot-in-the-loop control. These characteristics will be tested in a simulator study involving failed flight controls for a multi-engine aircraft.

Simple models for rope substructure mechanics: application to electro-mechanical lifts

NASA Astrophysics Data System (ADS)

Herrera, I.; Kaczmarczyk, S.

2016-05-01

Mechanical systems modelled as rigid mass elements connected by tensioned slender structural members such as ropes and cables represent quite common substructures used in lift engineering and hoisting applications. Special interest is devoted by engineers and researchers to the vibratory response of such systems for optimum performance and durability. This paper presents simplified models that can be employed to determine the natural frequencies of systems having substructures of two rigid masses constrained by tensioned rope/cable elements. The exact solution for free un-damped longitudinal displacement response is discussed in the context of simple two-degree-of-freedom models. The results are compared and the influence of characteristics parameters such as the ratio of the average mass of the two rigid masses with respect to the rope mass and the deviation ratio of the two rigid masses with respect to the average mass is analyzed. This analysis gives criteria for the application of such simplified models in complex elevator and hoisting system configurations.

A strategy for reducing turnaround time in design optimization using a distributed computer system

NASA Technical Reports Server (NTRS)

Young, Katherine C.; Padula, Sharon L.; Rogers, James L.

1988-01-01

There is a need to explore methods for reducing lengthly computer turnaround or clock time associated with engineering design problems. Different strategies can be employed to reduce this turnaround time. One strategy is to run validated analysis software on a network of existing smaller computers so that portions of the computation can be done in parallel. This paper focuses on the implementation of this method using two types of problems. The first type is a traditional structural design optimization problem, which is characterized by a simple data flow and a complicated analysis. The second type of problem uses an existing computer program designed to study multilevel optimization techniques. This problem is characterized by complicated data flow and a simple analysis. The paper shows that distributed computing can be a viable means for reducing computational turnaround time for engineering design problems that lend themselves to decomposition. Parallel computing can be accomplished with a minimal cost in terms of hardware and software.

Automatic speech recognition using a predictive echo state network classifier.

PubMed

Skowronski, Mark D; Harris, John G

2007-04-01

We have combined an echo state network (ESN) with a competitive state machine framework to create a classification engine called the predictive ESN classifier. We derive the expressions for training the predictive ESN classifier and show that the model was significantly more noise robust compared to a hidden Markov model in noisy speech classification experiments by 8+/-1 dB signal-to-noise ratio. The simple training algorithm and noise robustness of the predictive ESN classifier make it an attractive classification engine for automatic speech recognition.

IPAD applications to the design, analysis, and/or machining of aerospace structures. [Integrated Program for Aerospace-vehicle Design

NASA Technical Reports Server (NTRS)

Blackburn, C. L.; Dovi, A. R.; Kurtze, W. L.; Storaasli, O. O.

1981-01-01

A computer software system for the processing and integration of engineering data and programs, called IPAD (Integrated Programs for Aerospace-Vehicle Design), is described. The ability of the system to relieve the engineer of the mundane task of input data preparation is demonstrated by the application of a prototype system to the design, analysis, and/or machining of three simple structures. Future work to further enhance the system's automated data handling and ability to handle larger and more varied design problems are also presented.

Gas flow calculation method of a ramjet engine

NASA Astrophysics Data System (ADS)

Kostyushin, Kirill; Kagenov, Anuar; Eremin, Ivan; Zhiltsov, Konstantin; Shuvarikov, Vladimir

2017-11-01

At the present study calculation methodology of gas dynamics equations in ramjet engine is presented. The algorithm is based on Godunov`s scheme. For realization of calculation algorithm, the system of data storage is offered, the system does not depend on mesh topology, and it allows using the computational meshes with arbitrary number of cell faces. The algorithm of building a block-structured grid is given. Calculation algorithm in the software package "FlashFlow" is implemented. Software package is verified on the calculations of simple configurations of air intakes and scramjet models.

Magnetically engineered smart thin films: toward lab-on-chip ultra-sensitive molecular imaging.

PubMed

Hassan, Muhammad A; Saqib, Mudassara; Shaikh, Haseeb; Ahmad, Nasir M; Elaissari, Abdelhamid

2013-03-01

Magnetically responsive engineered smart thin films of nanoferrites as contrast agent are employed to develop surface based magnetic resonance imaging to acquire simple yet fast molecular imaging. The work presented here can be of significant potential for future lab-on-chip point-of-care diagnostics from the whole blood pool on almost any substrates to reduce or even prevent clinical studies involve a living organism to enhance the non-invasive imaging to advance the '3Rs' of work in animals-replacement, refinement and reduction.

The 25 kWe solar thermal Stirling hydraulic engine system: Conceptual design

NASA Technical Reports Server (NTRS)

White, Maurice; Emigh, Grant; Noble, Jack; Riggle, Peter; Sorenson, Torvald

1988-01-01

The conceptual design and analysis of a solar thermal free-piston Stirling hydraulic engine system designed to deliver 25 kWe when coupled to a 11 meter test bed concentrator is documented. A manufacturing cost assessment for 10,000 units per year was made. The design meets all program objectives including a 60,000 hr design life, dynamic balancing, fully automated control, more than 33.3 percent overall system efficiency, properly conditioned power, maximum utilization of annualized insolation, and projected production costs. The system incorporates a simple, rugged, reliable pool boiler reflux heat pipe to transfer heat from the solar receiver to the Stirling engine. The free-piston engine produces high pressure hydraulic flow which powers a commercial hydraulic motor that, in turn, drives a commercial rotary induction generator. The Stirling hydraulic engine uses hermetic bellows seals to separate helium working gas from hydraulic fluid which provides hydrodynamic lubrication to all moving parts. Maximum utilization of highly refined, field proven commercial components for electric power generation minimizes development cost and risk.

MD-11 PCA - View of aircraft on ramp

NASA Technical Reports Server (NTRS)

1995-01-01

This McDonnell Douglas MD-11 is taxiing to a position on the flightline at NASA's Dryden Flight Research Center, Edwards, California, following its completion of the first and second landings ever performed by a transport aircraft under engine power only (on Aug. 29, 1995). The milestone flight, with NASA research pilot and former astronaut Gordon Fullerton at the controls, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when its normal control surfaces are disabled. The Propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple. For pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

MD-11 PCA - First Landing at Edwards

NASA Technical Reports Server (NTRS)

1995-01-01

A transport aircraft lands for the first time under engine power only, as this McDonnell Douglas MD-11 touches down at 11:38 a.m., Aug. 29, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The milestone flight, flown by NASA research pilot and former astronaut Gordon Fullerton, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when its normal control surfaces are disabled. The propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple--for pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

MD-11 PCA - Closeup view of aircraft on ramp

NASA Technical Reports Server (NTRS)

1995-01-01

This McDonnell Douglas MD-11 has taxied to a position on the flightline at NASA's Dryden Flight Research Center, Edwards, California, following its completion of the first and second landings ever performed by a transport aircraft under engine power only (on Aug. 29, 1995). The milestone flight, with NASA research pilot and former astronaut Gordon Fullerton at the controls, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when its normal control surfaces are disabled. The Propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple. For pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

MD-11 PCA - First Landing at Edwards

NASA Technical Reports Server (NTRS)

1995-01-01

A transport aircraft lands for the first time under engine power only, as this McDonnell Douglas MD-11 touches down at 11:38 a.m., Aug. 29, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The milestone flight, flown by NASA research pilot and former astronaut Gordon Fullerton, was part of a NASA project to develop a computer-assisted engine control system that enables a pilot to land a plane safely when its normal control surfaces are disabled. The Propulsion-Controlled Aircraft (PCA) system uses standard autopilot controls already present in the cockpit, together with the new programming in the aircraft's flight control computers. The PCA concept is simple--for pitch control, the program increases thrust to climb and reduces thrust to descend. To turn right, the autopilot increases the left engine thrust while decreasing the right engine thrust. The initial Propulsion-Controlled Aircraft studies by NASA were carried out at Dryden with a modified twin-engine F-15 research aircraft.

High-speed engine/component performance assessment using exergy and thrust-based methods

NASA Technical Reports Server (NTRS)

Riggins, D. W.

1996-01-01

This investigation summarizes a comparative study of two high-speed engine performance assessment techniques based on energy (available work) and thrust-potential (thrust availability). Simple flow-fields utilizing Rayleigh heat addition and one-dimensional flow with friction are used to demonstrate the fundamental inability of conventional energy techniques to predict engine component performance, aid in component design, or accurately assess flow losses. The use of the thrust-based method on these same examples demonstrates its ability to yield useful information in all these categories. Energy and thrust are related and discussed from the stand-point of their fundamental thermodynamic and fluid dynamic definitions in order to explain the differences in information obtained using the two methods. The conventional definition of energy is shown to include work which is inherently unavailable to an aerospace Brayton engine. An engine-based energy is then developed which accurately accounts for this inherently unavailable work; performance parameters based on this quantity are then shown to yield design and loss information equivalent to the thrust-based method.

An Integrated Product Environment

NASA Technical Reports Server (NTRS)

Higgins, Chuck

1997-01-01

Mechanical Advantage is a mechanical design decision support system. Unlike our CAD/CAM cousins, Mechanical Advantage addresses true engineering processes, not just the form and fit of geometry. If we look at a traditional engineering environment, we see that an engineer starts with two things - performance goals and design rules. The intent is to have a product perform specific functions and accomplish that within a designated environment. Geometry should be a simple byproduct of that engineering process - not the controller of it. Mechanical Advantage is a performance modeler allowing engineers to consider all these criteria in making their decisions by providing such capabilities as critical parameter analysis, tolerance and sensitivity analysis, math driven Geometry, and automated design optimizations. If you should desire an industry standard solid model, we would produce an ACIS-based solid model. If you should desire an ANSI/ISO standard drawing, we would produce this as well with a virtual push of the button. For more information on this and other Advantage Series products, please contact the author.

Large-Scale Wind-Tunnel Tests of Exhaust Ingestion Due to Thrust Reversal on a Four-Engine Jet Transport during Ground Roll

NASA Technical Reports Server (NTRS)

Tolhurst, William H., Jr.; Hickey, David H.; Aoyagi, Kiyoshi

1961-01-01

Wind-tunnel tests have been conducted on a large-scale model of a swept-wing jet transport type airplane to study the factors affecting exhaust gas ingestion into the engine inlets when thrust reversal is used during ground roll. The model was equipped with four small jet engines mounted in nacelles beneath the wing. The tests included studies of both cascade and target type reversers. The data obtained included the free-stream velocity at the occurrence of exhaust gas ingestion in the outboard engine and the increment of drag due to thrust reversal for various modifications of thrust reverser configuration. Motion picture films of smoke flow studies were also obtained to supplement the data. The results show that the free-stream velocity at which ingestion occurred in the outboard engines could be reduced considerably, by simple modifications to the reversers, without reducing the effective drag due to reversed thrust.

Compression-ignition engine tests of several fuels

NASA Technical Reports Server (NTRS)

Spanogle, J A

1932-01-01

The tests reported in this paper were made to devise simple engine tests which would rate fuels as to their comparative value and their suitability for the operating conditions of the individual engine on which the tests are made. Three commercial fuels were used in two test engines having combustion chambers with and without effective air flow. Strictly comparative performance tests gave almost identical results for the three fuels. Analysis of indicator cards allowed a differentiation between fuels on a basis of rates of combustion. The same comparative ratings were obtained by determining the consistent operating range of injection advance angle for the three fuels. The difference in fuels is more pronounced in a quiescent combustion chamber than in one with high-velocity air flow. A fuel is considered suitable for the operating conditions of an engine with a quiescent combustion chamber if it permits the injection of the fuel to be advanced beyond the optimum without exceeding allowable knock or allowable maximum cylinder pressures.

Fault detection and accommodation testing on an F100 engine in an F-15 airplane

NASA Technical Reports Server (NTRS)

Myers, L. P.; Baer-Riedhart, J. L.; Maxwell, M. D.

1985-01-01

The fault detection and accommodation (FDA) methodology for digital engine-control systems may range from simple comparisons of redundant parameters to the more complex and sophisticated observer models of the entire engine system. Evaluations of the various FDA schemes are done using analytical methods, simulation, and limited-altitude-facility testing. Flight testing of the FDA logic has been minimal because of the difficulty of inducing realistic faults in flight. A flight program was conducted to evaluate the fault detection and accommodation capability of a digital electronic engine control in an F-15 aircraft. The objective of the flight program was to induce selected faults and evaluate the resulting actions of the digital engine controller. Comparisons were made between the flight results and predictions. Several anomalies were found in flight and during the ground test. Simulation results showed that the inducement of dual pressure failures was not feasible since the FDA logic was not designed to accommodate these types of failures.

Controlling Self-Assembly of Engineered Peptides on Graphite by Rational Mutation

PubMed Central

So, Christopher R.; Hayamizu, Yuhei; Yazici, Hilal; Gresswell, Carolyn; Khatayevich, Dmitriy; Tamerler, Candan; Sarikaya, Mehmet

2012-01-01

Self-assembly of proteins on surfaces is utilized in many fields to integrate intricate biological structures and diverse functions with engineered materials. Controlling proteins at bio-solid interfaces relies on establishing key correlations between their primary sequences and resulting spatial organizations on substrates. Protein self-assembly, however, remains an engineering challenge. As a novel approach, we demonstrate here that short dodecapeptides selected by phage display are capable of self-assembly on graphite and form long-range ordered biomolecular nanostructures. Using atomic force microscopy and contact angle studies, we identify three amino-acid domains along the primary sequence that steer peptide ordering and lead to nanostructures with uniformly displayed residues. The peptides are further engineered via simple mutations to control fundamental interfacial processes, including initial binding, surface aggregation and growth kinetics, and intermolecular interactions. Tailoring short peptides via their primary sequence offers versatile control over molecular self-assembly, resulting in well-defined surface properties essential in building engineered, chemically rich, bio-solid interfaces. PMID:22233341

Exhaust-stack nozzle area and shape for individual cylinder exhaust-gas jet-propulsion system

NASA Technical Reports Server (NTRS)

Pinkel, Benjamin; Turner, Richard; Voss, Fred; Humble, Leroy V

1943-01-01

This report presents the results of an investigation conducted on the effect of exhaust-stack nozzle area, shape, and length on engine power, jet thrust, and gain in net thrust (engine propeller plus jet). Single-cylinder engine data were obtained using three straight stacks 25, 44, and 108 inches in length; an S-shaped stack, a 90 degree bend, a 180 degree bend, and a short straight stack having a closed branch faired into it. Each stack was fitted with nozzles varying in exit area from 0.91 square inch to the unrestricted area of the stack of 4.20 square inches. The engine was generally operated over a range of engine speeds from 1300 to 2100 r.p.m, inlet-manifold pressures from 22 to 30 inches of mercury absolute, and a fuel-air ratio of 0.08. The loss in engine power, the jet thrust, and the gain in net thrust are correlated in terms of several simple parameters. An example is given for determining the optimum nozzle area and the overall net thrust.

Parametric scramjet analysis

NASA Astrophysics Data System (ADS)

Choi, Jongseong

The performance of a hypersonic flight vehicle will depend on existing materials and fuels; this work presents the performance of the ideal scramjet engine for three different combustion chamber materials and three different candidate fuels. Engine performance is explored by parametric cycle analysis for the ideal scramjet as a function of material maximum service temperature and the lower heating value of jet engine fuels. The thermodynamic analysis is based on the Brayton cycle as similarly employed in describing the performance of the ramjet, turbojet, and fanjet ideal engines. The objective of this work is to explore material operating temperatures and fuel possibilities for the combustion chamber of a scramjet propulsion system to show how they relate to scramjet performance and the seven scramjet engine parameters: specific thrust, fuel-to-air ratio, thrust-specific fuel consumption, thermal efficiency, propulsive efficiency, overall efficiency, and thrust flux. The information presented in this work has not been done by others in the scientific literature. This work yields simple algebraic equations for scramjet performance which are similar to that of the ideal ramjet, ideal turbojet and ideal turbofan engines.

Single rotor turbine engine

DOEpatents

Platts, David A.

2002-01-01

There has been invented a turbine engine with a single rotor which cools the engine, functions as a radial compressor, pushes air through the engine to the ignition point, and acts as an axial turbine for powering the compressor. The invention engine is designed to use a simple scheme of conventional passage shapes to provide both a radial and axial flow pattern through the single rotor, thereby allowing the radial intake air flow to cool the turbine blades and turbine exhaust gases in an axial flow to be used for energy transfer. In an alternative embodiment, an electric generator is incorporated in the engine to specifically adapt the invention for power generation. Magnets are embedded in the exhaust face of the single rotor proximate to a ring of stationary magnetic cores with windings to provide for the generation of electricity. In this alternative embodiment, the turbine is a radial inflow turbine rather than an axial turbine as used in the first embodiment. Radial inflow passages of conventional design are interleaved with radial compressor passages to allow the intake air to cool the turbine blades.

Fastrac Nozzle Design, Performance and Development

NASA Technical Reports Server (NTRS)

Peters, Warren; Rogers, Pat; Lawrence, Tim; Davis, Darrell; DAgostino, Mark; Brown, Andy

2000-01-01

With the goal of lowering the cost of payload to orbit, NASA/MSFC (Marshall Space Flight Center) researched ways to decrease the complexity and cost of an engine system and its components for a small two-stage booster vehicle. The composite nozzle for this Fastrac Engine was designed, built and tested by MSFC with fabrication support and engineering from Thiokol-SEHO (Science and Engineering Huntsville Operation). The Fastrac nozzle uses materials, fabrication processes and design features that are inexpensive, simple and easily manufactured. As the low cost nozzle (and injector) design matured through the subscale tests and into full scale hot fire testing, X-34 chose the Fastrac engine for the propulsion plant for the X-34. Modifications were made to nozzle design in order to meet the new flight requirements. The nozzle design has evolved through subscale testing and manufacturing demonstrations to full CFD (Computational Fluid Dynamics), thermal, thermomechanical and dynamic analysis and the required component and engine system tests to validate the design. The Fastrac nozzle is now in final development hot fire testing and has successfully accumulated 66 hot fire tests and 1804 seconds on 18 different nozzles.

Quantum dynamical framework for Brownian heat engines

NASA Astrophysics Data System (ADS)

Agarwal, G. S.; Chaturvedi, S.

2013-07-01

We present a self-contained formalism modeled after the Brownian motion of a quantum harmonic oscillator for describing the performance of microscopic Brownian heat engines such as Carnot, Stirling, and Otto engines. Our theory, besides reproducing the standard thermodynamics results in the steady state, enables us to study the role dissipation plays in determining the efficiency of Brownian heat engines under actual laboratory conditions. In particular, we analyze in detail the dynamics associated with decoupling a system in equilibrium with one bath and recoupling it to another bath and obtain exact analytical results, which are shown to have significant ramifications on the efficiencies of engines involving such a step. We also develop a simple yet powerful technique for computing corrections to the steady state results arising from finite operation time and use it to arrive at the thermodynamic complementarity relations for various operating conditions and also to compute the efficiencies of the three engines cited above at maximum power. Some of the methods and exactly solvable models presented here are interesting in their own right and could find useful applications in other contexts as well.

A Model-Based Anomaly Detection Approach for Analyzing Streaming Aircraft Engine Measurement Data

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Rinehart, Aidan W.

2014-01-01

This paper presents a model-based anomaly detection architecture designed for analyzing streaming transient aircraft engine measurement data. The technique calculates and monitors residuals between sensed engine outputs and model predicted outputs for anomaly detection purposes. Pivotal to the performance of this technique is the ability to construct a model that accurately reflects the nominal operating performance of the engine. The dynamic model applied in the architecture is a piecewise linear design comprising steady-state trim points and dynamic state space matrices. A simple curve-fitting technique for updating the model trim point information based on steadystate information extracted from available nominal engine measurement data is presented. Results from the application of the model-based approach for processing actual engine test data are shown. These include both nominal fault-free test case data and seeded fault test case data. The results indicate that the updates applied to improve the model trim point information also improve anomaly detection performance. Recommendations for follow-on enhancements to the technique are also presented and discussed.

A Model-Based Anomaly Detection Approach for Analyzing Streaming Aircraft Engine Measurement Data

NASA Technical Reports Server (NTRS)

Simon, Donald L.; Rinehart, Aidan Walker

2015-01-01

This paper presents a model-based anomaly detection architecture designed for analyzing streaming transient aircraft engine measurement data. The technique calculates and monitors residuals between sensed engine outputs and model predicted outputs for anomaly detection purposes. Pivotal to the performance of this technique is the ability to construct a model that accurately reflects the nominal operating performance of the engine. The dynamic model applied in the architecture is a piecewise linear design comprising steady-state trim points and dynamic state space matrices. A simple curve-fitting technique for updating the model trim point information based on steadystate information extracted from available nominal engine measurement data is presented. Results from the application of the model-based approach for processing actual engine test data are shown. These include both nominal fault-free test case data and seeded fault test case data. The results indicate that the updates applied to improve the model trim point information also improve anomaly detection performance. Recommendations for follow-on enhancements to the technique are also presented and discussed.

The design and fabrication of a Stirling engine heat exchanger module with an integral heat pipe

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.

1988-01-01

The conceptual design of a free-piston Stirling Space Engine (SSE) intended for space power applications has been generated. The engine was designed to produce 25 kW of electric power with heat supplied by a nuclear reactor. A novel heat exchanger module was designed to reduce the number of critical joints in the heat exchanger assembly while also incorporating a heat pipe as the link between the engine and the heat source. Two inexpensive verification tests are proposed. The SSE heat exchanger module is described and the operating conditions for the module are outlined. The design process of the heat exchanger modules, including the sodium heat pipe, is briefly described. Similarities between the proposed SSE heat exchanger modules and the LeRC test modules for two test engines are presented. The benefits and weaknesses of using a sodium heat pipe to transport heat to a Stirling engine are discussed. Similarly, the problems encountered when using a true heat pipe, as opposed to a more simple reflux boiler, are described. The instruments incorporated into the modules and the test program are also outlined.

Schlieren image velocimetry measurements in a rocket engine exhaust plume

NASA Astrophysics Data System (ADS)

Morales, Rudy; Peguero, Julio; Hargather, Michael

2017-11-01

Schlieren image velocimetry (SIV) measures velocity fields by tracking the motion of naturally-occurring turbulent flow features in a compressible flow. Here the technique is applied to measuring the exhaust velocity profile of a liquid rocket engine. The SIV measurements presented include discussion of visibility of structures, image pre-processing for structure visibility, and ability to process resulting images using commercial particle image velocimetry (PIV) codes. The small-scale liquid bipropellant rocket engine operates on nitrous oxide and ethanol as propellants. Predictions of the exhaust velocity are obtained through NASA CEA calculations and simple compressible flow relationships, which are compared against the measured SIV profiles. Analysis of shear layer turbulence along the exhaust plume edge is also presented.

ARROWSMITH-P: A prototype expert system for software engineering management

NASA Technical Reports Server (NTRS)

Basili, Victor R.; Ramsey, Connie Loggia

1985-01-01

Although the field of software engineering is relatively new, it can benefit from the use of expert systems. Two prototype expert systems were developed to aid in software engineering management. Given the values for certain metrics, these systems will provide interpretations which explain any abnormal patterns of these values during the development of a software project. The two systems, which solve the same problem, were built using different methods, rule-based deduction and frame-based abduction. A comparison was done to see which method was better suited to the needs of this field. It was found that both systems performed moderately well, but the rule-based deduction system using simple rules provided more complete solutions than did the frame-based abduction system.

Reuleaux models at St. Petersburg State University

NASA Astrophysics Data System (ADS)

Kuteeva, G. A.; Sinilshchikova, G. A.; Trifonenko, B. V.

2018-05-01

Franz Reuleaux (1829 - 1905) is a famous mechanical engineer, a Professor of the Berlin Royal Technical Academy. He became widely known as an engineer-scientist, a Professor and industrial consultant, education reformer and leader of the technical elite of Germany. He directed the design and manufacture of over 300 models of simple mechanisms. They were sold to many famous universities for pedagogical and scientific purposes. Today, the most complete set is at Cornell University, College of Engineering. In this article we discuss the history, the modern state and our using the Reuleaux models that survived at St. Petersburg State University for educational purposes. We present description of certain models and our electronic resource with these models. We provide the information of similar electronic resources from other universities.

Calculated and measured stresses in simple panels subject to intense random acoustic loading including the near noise field of a turbojet engine

NASA Technical Reports Server (NTRS)

Lassiter, Leslie W; Hess, Robert W

1958-01-01

Flat 2024-t3 aluminum panels measuring 11 inches by 13 inches were tested in the near noise fields of a 4-inch air jet and turbojet engine. The stresses which were developed in the panels are compared with those calculated by generalized harmonic analysis. The calculated and measured stresses were found to be in good agreement. In order to make the stress calculations, supplementary data relating to the transfer characteristics, damping, and static response of flat and curved panels under periodic loading are necessary and were determined experimentally. In addition, an appendix containing detailed data on the near pressure field of the turbojet engine is included.

An investigation of the effect of instruction in physics on the formation of mental models for problem-solving in the context of simple electric circuits

NASA Astrophysics Data System (ADS)

Beh, Kian Lim

2000-10-01

This study was designed to explore the effect of a typical traditional method of instruction in physics on the formation of useful mental models among college students for problem-solving using simple electric circuits as a context. The study was also aimed at providing a comprehensive description of the understanding regarding electric circuits among novices and experts. In order to achieve these objectives, the following two research approaches were employed: (1) A students survey to collect data from 268 physics students; and (2) An interview protocol to collect data from 23 physics students and 24 experts (including 10 electrical engineering graduates, 4 practicing electrical engineers, 2 secondary school physics teachers, 8 physics lecturers, and 4 electrical engineers). Among the major findings are: (1) Most students do not possess accurate models of simple electric circuits as presented implicitly in physics textbooks; (2) Most students display good procedural understanding for solving simple problems concerning electric circuits but have no in-depth conceptual understanding in terms of practical knowledge of current, voltage, resistance, and circuit connections; (3) Most students encounter difficulty in discerning parallel connections that are drawn in a non-conventional format; (4) After a year of college physics, students show significant improvement in areas, including practical knowledge of current and voltage, ability to compute effective resistance and capacitance, ability to identify circuit connections, and ability to solve problems; however, no significance was found in practical knowledge of resistance and ability to connect circuits; and (5) The differences and similarities between the physics students and the experts include: (a) Novices perceive parallel circuits more in terms of 'branch', 'current', and 'resistors with the same resistance' while experts perceive parallel circuits more in terms of 'node', 'voltage', and 'less resistance'; and (b) Both novices and experts use phrases such as 'side-by side' and 'one on top of the other' in describing parallel circuits which emphasize the geometry of the standard circuit drawing when describing parallel resistors.

Efficiency bounds for nonequilibrium heat engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehta, Pankaj; Polkovnikov, Anatoli, E-mail: asp@bu.edu

2013-05-15

We analyze the efficiency of thermal engines (either quantum or classical) working with a single heat reservoir like an atmosphere. The engine first gets an energy intake, which can be done in an arbitrary nonequilibrium way e.g. combustion of fuel. Then the engine performs the work and returns to the initial state. We distinguish two general classes of engines where the working body first equilibrates within itself and then performs the work (ergodic engine) or when it performs the work before equilibrating (non-ergodic engine). We show that in both cases the second law of thermodynamics limits their efficiency. For ergodicmore » engines we find a rigorous upper bound for the efficiency, which is strictly smaller than the equivalent Carnot efficiency. I.e. the Carnot efficiency can be never achieved in single reservoir heat engines. For non-ergodic engines the efficiency can be higher and can exceed the equilibrium Carnot bound. By extending the fundamental thermodynamic relation to nonequilibrium processes, we find a rigorous thermodynamic bound for the efficiency of both ergodic and non-ergodic engines and show that it is given by the relative entropy of the nonequilibrium and initial equilibrium distributions. These results suggest a new general strategy for designing more efficient engines. We illustrate our ideas by using simple examples. -- Highlights: ► Derived efficiency bounds for heat engines working with a single reservoir. ► Analyzed both ergodic and non-ergodic engines. ► Showed that non-ergodic engines can be more efficient. ► Extended fundamental thermodynamic relation to arbitrary nonequilibrium processes.« less

The Diffusion Simulator - Teaching Geomorphic and Geologic Problems Visually.

ERIC Educational Resources Information Center

Gilbert, R.

1979-01-01

Describes a simple hydraulic simulator based on more complex models long used by engineers to develop approximate solutions. It allows students to visualize non-steady transfer, to apply a model to solve a problem, and to compare experimentally simulated information with calculated values. (Author/MA)

A Grand Sale: $12 for a Dozen Experiments in CRE.

ERIC Educational Resources Information Center

Guo-Tai, Zhang; Shau-Drang, Hau

1984-01-01

Introduces a procedure for a whole class of experiments which require very simple and inexpensive equipment and which illustrate one of the basic problems of chemical reaction engineering. The reactions are designed to allow development of a kinetic rate equation from laboratory data. (JM)

Capacitors and Resistance-Capacitance Networks.

ERIC Educational Resources Information Center

Balabanian, Norman; Root, Augustin A.

This programed textbook was developed under a contract with the United States Office of Education as Number 5 in a series of materials for use in an electrical engineering sequence. It is divided into three parts--(1) capacitors, (2) voltage-current relationships, and (3) simple resistance-capacitance networks. (DH)

Let Students Discover an Important Physical Property of a Slinky

ERIC Educational Resources Information Center

Gash, Philip

2016-01-01

This paper describes a simple experiment that lets first-year physics and engineering students discover an important physical property of a Slinky. The restoring force for the fundamental oscillation frequency is provided only by those coils between the support and the Slinky center of mass.

Search without Boundaries Using Simple APIs

ERIC Educational Resources Information Center

Tong, Qi (Helen)

2009-01-01

The U.S. Geological Survey (USGS) Library, where the author serves as the digital services librarian, is increasingly challenged to make it easier for users to find information from many heterogeneous information sources. Information is scattered throughout different software applications (i.e., library catalog, federated search engine, link…

Plasma Properties in the Plume of a Hall Thruster Cluster

DTIC Science & Technology

2003-06-04

The Hall thruster cluster is an attractive propulsion approach for spacecraft requiring very high-power electric propulsion systems. This article...probes in the plume of a low-power, four-engine Hall thruster cluster. Simple analytical formulas are introduced that allow these quantities to be

Literature review : simple test method for possible use in predicting the fatigue of asphaltic concrete.

DOT National Transportation Integrated Search

1975-01-01

It has been recognized for many years that fatigue is one of many mechanisms by which asphaltic concrete pavements fail. Experience and empirical design procedures such as those developed by Marshall and Hveem have enabled engineers to design-mixture...

Extended temperature range ACPS thruster investigation

NASA Technical Reports Server (NTRS)

Blubaugh, A. L.; Schoenman, L.

1974-01-01

The successful hot fire demonstration of a pulsing liquid hydrogen/liquid oxygen and gaseous hydrogen/liquid oxygen attitude control propulsion system thruster is described. The test was the result of research to develop a simple, lightweight, and high performance reaction control system without the traditional requirements for extensive periods of engine thermal conditioning, or the use of complex equipment to convert both liquid propellants to gas prior to delivery to the engine. Significant departures from conventional injector design practice were employed to achieve an operable design. The work discussed includes thermal and injector manifold priming analyses, subscale injector chilldown tests, and 168 full scale and 550 N (1250 lbF) rocket engine tests. Ignition experiments, at propellant temperatures ranging from cryogenic to ambient, led to the generation of a universal spark ignition system which can reliably ignite an engine when supplied with liquid, two phase, or gaseous propellants. Electrical power requirements for spark igniter are very low.

Turbine adapted maps for turbocharger engine matching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tancrez, M.; Galindo, J.; Guardiola, C.

2011-01-15

This paper presents a new representation of the turbine performance maps oriented for turbocharger characterization. The aim of this plot is to provide a more compact and suited form to implement in engine simulation models and to interpolate data from turbocharger test bench. The new map is based on the use of conservative parameters as turbocharger power and turbine mass flow to describe the turbine performance in all VGT positions. The curves obtained are accurately fitted with quadratic polynomials and simple interpolation techniques give reliable results. Two turbochargers characterized in an steady flow rig were used for illustrating the representation.more » After being implemented in a turbocharger submodel, the results obtained with the model have been compared with success against turbine performance evaluated in engine tests cells. A practical application in turbocharger matching is also provided to show how this new map can be directly employed in engine design. (author)« less

A World Wide Web (WWW) server database engine for an organelle database, MitoDat.

PubMed

Lemkin, P F; Chipperfield, M; Merril, C; Zullo, S

1996-03-01

We describe a simple database search engine "dbEngine" which may be used to quickly create a searchable database on a World Wide Web (WWW) server. Data may be prepared from spreadsheet programs (such as Excel, etc.) or from tables exported from relationship database systems. This Common Gateway Interface (CGI-BIN) program is used with a WWW server such as available commercially, or from National Center for Supercomputer Algorithms (NCSA) or CERN. Its capabilities include: (i) searching records by combinations of terms connected with ANDs or ORs; (ii) returning search results as hypertext links to other WWW database servers; (iii) mapping lists of literature reference identifiers to the full references; (iv) creating bidirectional hypertext links between pictures and the database. DbEngine has been used to support the MitoDat database (Mendelian and non-Mendelian inheritance associated with the Mitochondrion) on the WWW.

Second Law based definition of passivity/activity of devices

NASA Astrophysics Data System (ADS)

Sundqvist, Kyle M.; Ferry, David K.; Kish, Laszlo B.

2017-10-01

Recently, our efforts to clarify the old question, if a memristor is a passive or active device [1], triggered debates between engineers, who have had advanced definitions of passivity/activity of devices, and physicists with significantly different views about this seemingly simple question. This debate triggered our efforts to test the well-known engineering concepts about passivity/activity in a deeper way, challenging them by statistical physics. It is shown that the advanced engineering definition of passivity/activity of devices is self-contradictory when a thermodynamical system executing Johnson-Nyquist noise is present. A new, statistical physical, self-consistent definition based on the Second Law of Thermodynamics is introduced. It is also shown that, in a system with uniform temperature distribution, any rectifier circuitry that can rectify thermal noise must contain an active circuit element, according to both the engineering and statistical physical definitions.

Computational Fluid Dynamics Modeling of a Supersonic Nozzle and Integration into a Variable Cycle Engine Model

NASA Technical Reports Server (NTRS)

Connolly, Joseph W.; Friedlander, David; Kopasakis, George

2015-01-01

This paper covers the development of an integrated nonlinear dynamic simulation for a variable cycle turbofan engine and nozzle that can be integrated with an overall vehicle Aero-Propulso-Servo-Elastic (APSE) model. A previously developed variable cycle turbofan engine model is used for this study and is enhanced here to include variable guide vanes allowing for operation across the supersonic flight regime. The primary focus of this study is to improve the fidelity of the model's thrust response by replacing the simple choked flow equation convergent-divergent nozzle model with a MacCormack method based quasi-1D model. The dynamic response of the nozzle model using the MacCormack method is verified by comparing it against a model of the nozzle using the conservation element/solution element method. A methodology is also presented for the integration of the MacCormack nozzle model with the variable cycle engine.

Computational Fluid Dynamics Modeling of a Supersonic Nozzle and Integration into a Variable Cycle Engine Model

NASA Technical Reports Server (NTRS)

Connolly, Joseph W.; Friedlander, David; Kopasakis, George

2014-01-01

This paper covers the development of an integrated nonlinear dynamic simulation for a variable cycle turbofan engine and nozzle that can be integrated with an overall vehicle Aero-Propulso-Servo-Elastic (APSE) model. A previously developed variable cycle turbofan engine model is used for this study and is enhanced here to include variable guide vanes allowing for operation across the supersonic flight regime. The primary focus of this study is to improve the fidelity of the model's thrust response by replacing the simple choked flow equation convergent-divergent nozzle model with a MacCormack method based quasi-1D model. The dynamic response of the nozzle model using the MacCormack method is verified by comparing it against a model of the nozzle using the conservation element/solution element method. A methodology is also presented for the integration of the MacCormack nozzle model with the variable cycle engine.

An inference engine for embedded diagnostic systems

NASA Technical Reports Server (NTRS)

Fox, Barry R.; Brewster, Larry T.

1987-01-01

The implementation of an inference engine for embedded diagnostic systems is described. The system consists of two distinct parts. The first is an off-line compiler which accepts a propositional logical statement of the relationship between facts and conclusions and produces data structures required by the on-line inference engine. The second part consists of the inference engine and interface routines which accept assertions of fact and return the conclusions which necessarily follow. Given a set of assertions, it will generate exactly the conclusions which logically follow. At the same time, it will detect any inconsistencies which may propagate from an inconsistent set of assertions or a poorly formulated set of rules. The memory requirements are fixed and the worst case execution times are bounded at compile time. The data structures and inference algorithms are very simple and well understood. The data structures and algorithms are described in detail. The system has been implemented on Lisp, Pascal, and Modula-2.

Solving ordinary differential equations by electrical analogy: a multidisciplinary teaching tool

NASA Astrophysics Data System (ADS)

Sanchez Perez, J. F.; Conesa, M.; Alhama, I.

2016-11-01

Ordinary differential equations are the mathematical formulation for a great variety of problems in science and engineering, and frequently, two different problems are equivalent from a mathematical point of view when they are formulated by the same equations. Students acquire the knowledge of how to solve these equations (at least some types of them) using protocols and strict algorithms of mathematical calculation without thinking about the meaning of the equation. The aim of this work is that students learn to design network models or circuits in this way; with simple knowledge of them, students can establish the association of electric circuits and differential equations and their equivalences, from a formal point of view, that allows them to associate knowledge of two disciplines and promote the use of this interdisciplinary approach to address complex problems. Therefore, they learn to use a multidisciplinary tool that allows them to solve these kinds of equations, even students of first course of engineering, whatever the order, grade or type of non-linearity. This methodology has been implemented in numerous final degree projects in engineering and science, e.g., chemical engineering, building engineering, industrial engineering, mechanical engineering, architecture, etc. Applications are presented to illustrate the subject of this manuscript.

Thermodynamic feature of a Brownian heat engine operating between two heat baths.

PubMed

Asfaw, Mesfin

2014-01-01

A generalized theory of nonequilibrium thermodynamics for a Brownian motor operating between two different heat baths is presented. Via a simple paradigmatic model, we not only explore the thermodynamic feature of the engine in the regime of the nonequilibrium steady state but also study the short time behavior of the system for either the isothermal case with load or, in general, the nonisothermal case with or without load. Many elegant thermodynamic theories can be checked via the present model. Furthermore the dependence of the velocity, the efficiency, and the performance of the refrigerator on time t is examined. Our study reveals a current reversal due to time t. In the early system relaxation period, the model works neither as a heat engine nor as a refrigerator and only after a certain period of time does the model start functioning as a heat engine or as a refrigerator. The performance of the engine also improves with time and at steady state the engine manifests a higher efficiency or performance as a refrigerator. Furthermore the effect of energy exchange via the kinetic energy on the performance of the heat engine is explored.

When water meets behavioral economics (or: it is not all about money!)

NASA Astrophysics Data System (ADS)

Escriva-Bou, A.

2014-12-01

Water engineers do not like people; we are better with numbers, equations and models where people behavior is only a variable, usually constant, or in the best case a probabilistic approximation. On the other side, most economic studies relate to people's behavior, and when economists develop engineering-based models, engineers usually think that econometric approaches are too simple to represent complex systems that engineers like to work with. Besides this simple-minded cliche, there is a lot of field to explore in the intersections of both disciplines. Even though the development of infrastructure cost-benefit analyses after Dupuit's work, or the more recent growth of hydroeconomic modeling, we are still missing a lot of potential synergic benefits from integrating behavioral economics and water infrastructure design and management. To present a simple example: urban water infrastructure design is based on water peaks, so reservoirs, pump stations and pipe dimensions have to be built to serve these peaks; water-related energy assessment studies have shown that there is a lot of energy used for every drop of water used in our houses, farms, and industries, and energy peaks are even larger that water peaks, creating expensive troubles for energy supply; and all this energy consumption means greenhouse gas emissions. Therefore we agree that reducing water peaks might create a lot of benefits, but could water customers change their behavior? Which incentives do they need? It is only about money, or it may be managed with better information? Beyond this example there are many other promising economic topics that could help in our daily water problems, such as: game theoretic approaches to understand decisions; science-based agent models that help us to understand the performance of a system as the sum of agents' actions and interactions; or the analysis of institutional-driven management to avoid the tragedy of the commons that depletes groundwater resources globally. And no need to remind that all resource scarcity problems will increase with population growth, so it would be better to begin work sooner on these problems.

Tissue engineering: state of the art in oral rehabilitation

PubMed Central

SCHELLER, E. L.; KREBSBACH, P. H.; KOHN, D. H.

2009-01-01

SUMMARY More than 85% of the global population requires repair or replacement of a craniofacial structure. These defects range from simple tooth decay to radical oncologic craniofacial resection. Regeneration of oral and craniofacial tissues presents a formidable challenge that requires synthesis of basic science, clinical science and engineering technology. Identification of appropriate scaffolds, cell sources and spatial and temporal signals (the tissue engineering triad) is necessary to optimize development of a single tissue, hybrid organ or interface. Furthermore, combining the understanding of the interactions between molecules of the extracellular matrix and attached cells with an understanding of the gene expression needed to induce differentiation and tissue growth will provide the design basis for translating basic science into rationally developed components of this tissue engineering triad. Dental tissue engineers are interested in regeneration of teeth, oral mucosa, salivary glands, bone and periodontium. Many of these oral structures are hybrid tissues. For example, engineering the periodontium requires growth of alveolar bone, cementum and the periodontal ligament. Recapitulation of biological development of hybrid tissues and interfaces presents a challenge that exceeds that of engineering just a single tissue. Advances made in dental interface engineering will allow these tissues to serve as model systems for engineering other tissues or organs of the body. This review will begin by covering basic tissue engineering principles and strategic design of functional biomaterials. We will then explore the impact of biomaterials design on the status of craniofacial tissue engineering and current challenges and opportunities in dental tissue engineering. PMID:19228277

Tissue engineering: state of the art in oral rehabilitation.

PubMed

Scheller, E L; Krebsbach, P H; Kohn, D H

2009-05-01

More than 85% of the global population requires repair or replacement of a craniofacial structure. These defects range from simple tooth decay to radical oncologic craniofacial resection. Regeneration of oral and craniofacial tissues presents a formidable challenge that requires synthesis of basic science, clinical science and engineering technology. Identification of appropriate scaffolds, cell sources and spatial and temporal signals (the tissue engineering triad) is necessary to optimize development of a single tissue, hybrid organ or interface. Furthermore, combining the understanding of the interactions between molecules of the extracellular matrix and attached cells with an understanding of the gene expression needed to induce differentiation and tissue growth will provide the design basis for translating basic science into rationally developed components of this tissue engineering triad. Dental tissue engineers are interested in regeneration of teeth, oral mucosa, salivary glands, bone and periodontium. Many of these oral structures are hybrid tissues. For example, engineering the periodontium requires growth of alveolar bone, cementum and the periodontal ligament. Recapitulation of biological development of hybrid tissues and interfaces presents a challenge that exceeds that of engineering just a single tissue. Advances made in dental interface engineering will allow these tissues to serve as model systems for engineering other tissues or organs of the body. This review will begin by covering basic tissue engineering principles and strategic design of functional biomaterials. We will then explore the impact of biomaterials design on the status of craniofacial tissue engineering and current challenges and opportunities in dental tissue engineering.

Etched optical fiber vibration sensor to monitor health condition of beam like structures

NASA Astrophysics Data System (ADS)

Putha, Kishore; Dantala, Dinakar; Kamineni, Srimannarayana; Pachava, Vengal Rao

2013-06-01

Using a center etched single mode optical fiber, a simple vibration senor is designed to monitor the vibrations of a simply supported beam. The sensor has high linear response to the axial displacement of about 0.8 mm with a sensitivity of 32 mV/10 μm strain. The sensor is tested for periodic and suddenly released forces, and the results are found to coincide with the theoretical values. This simple design, small in size and low cost sensor may find applications in industry and civil engineering to monitor the vibrations of the beam structures and bridges.

At a glance: cellular biology for engineers.

PubMed

Khoshmanesh, K; Kouzani, A Z; Nahavandi, S; Baratchi, S; Kanwar, J R

2008-10-01

Engineering contributions have played an important role in the rise and evolution of cellular biology. Engineering technologies have helped biologists to explore the living organisms at cellular and molecular levels, and have created new opportunities to tackle the unsolved biological problems. There is now a growing demand to further expand the role of engineering in cellular biology research. For an engineer to play an effective role in cellular biology, the first essential step is to understand the cells and their components. However, the stumbling block of this step is to comprehend the information given in the cellular biology literature because it best suits the readers with a biological background. This paper aims to overcome this bottleneck by describing the human cell components as micro-plants that form cells as micro-bio-factories. This concept can accelerate the engineers' comprehension of the subject. In this paper, first the structure and function of different cell components are described. In addition, the engineering attempts to mimic various cell components through numerical modelling or physical implementation are highlighted. Next, the interaction of different cell components that facilitate complicated chemical processes, such as energy generation and protein synthesis, are described. These complex interactions are translated into simple flow diagrams, generally used by engineers to represent multi-component processes.

Teaching Electricity and Engineering with LEDs

ERIC Educational Resources Information Center

Johnstone, Christopher

2014-01-01

When learning about electricity, students are typically asked to complete a simple circuit involving a battery, wire, and lightbulb. This activity can be enhanced by adding discussion and discourse and can take on a unique final form in the case of "The Friendship Detector." In such electrical circuit activities, the completed circuit is…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Wei; Reese, Cassandra M.; Xiong, Li

We report a simple route to engineer ultrathin polymer brush surfaces with wrinkled morphologies using postpolymerization modification (PPM), where the length scale of the buckled features can be tuned using PPM reaction time. Here, we show that partial crosslinking of the outer layer of the polymer brush under poor solvent conditions is critical to obtain wrinkled morphologies upon swelling.

Suspension and Characterization of Aqueous C60 Nanomaterials in Natural and Engineered Waters

EPA Science Inventory

Many current studies on the aqueous suspension of fullerene (aqu/C60) have used deionized water or simple salt solutions, and as a result little is know about the suspension of fullerene nanomatierals under environmentally relevant conditions, such as solutions that contain organ...

CURTIS TAYLOR, PRESIDENT OF LINC RESEARCH CORP.

NASA Image and Video Library

2016-04-27

CURTIS O. TAYLOR, PRESIDENT OF LINC RESEARCH CORP, (L), AND JEFF LINDNER, CHIEF ENGINEER, POSE WITH HARDWARE FOR THEIR PATENTED TECHNOLOGY, FLUID STRUCTURE COUPLING, WHICH USES SIMPLE PHYSICS TO DAMPEN POTENTIALLY HARMFUL SHAKING IN STRUCTURES. INSTALLATION OF THE FLUID STRUCTURE COUPLING TECHNOLOGY IN A BUILDING WILL TAKE PLACE IN SUMMER OF 2016.

Turning the Corner

ERIC Educational Resources Information Center

Cooper, Kenneth J.

2012-01-01

Stacyann Morgan got into biomedical engineering through a simple Google search. She got through an undergraduate program in the emerging field thanks to a federally-funded program that provided multi-layered support to Black and Latino students at City College of New York. Starting in 2001, the National Institutes of Health funded the Minority…

Fourier Analysis and the Rhythm of Conversation.

ERIC Educational Resources Information Center

Dabbs, James M., Jr.

Fourier analysis, a common technique in engineering, breaks down a complex wave form into its simple sine wave components. Communication researchers have recently suggested that this technique may provide an index of the rhythm of conversation, since vocalizing and pausing produce a complex wave form pattern of alternation between two speakers. To…

Communicating Networked Control Systems

DTIC Science & Technology

2007-03-31

Parker, G. G., Bettig B. P., and Bifano T.G., “Simple models for piston- type micromirror behavior,” J. Micromech. Microeng. [16] pp. 303–313, 2006...Optical Engineering [41]3, pp. 561-566, 2002. 37. Horenstein, M., Pappas, S., Fishov, A., and Bifano, T.G., “Electrostatic Micromirrors for Subaperturing

Using Visualization and Computation in the Analysis of Separation Processes

ERIC Educational Resources Information Center

Joo, Yong Lak; Choudhary, Devashish

2006-01-01

For decades, every chemical engineer has been asked to have a background in separations. The required separations course can, however, be uninspiring and superficial because understanding many separation processes involves conventional graphical methods and commercial process simulators. We utilize simple, user-­friendly mathematical software,…

iss053e210425

NASA Image and Video Library

2017-11-07

iss053e210425 (Nov. 7, 2017) --- Flight Engineer Joe Acaba holds a children's book that he is reading from as part of the Story Time From Space program. Astronauts read aloud from a STEM-related children's book while being videotaped and demonstrate simple science concepts and experiments aboard the International Space Station.

75 FR 56477 - Technical Amendments for Marine Spark-Ignition Engines and Vessels

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

... spillage, incorporating safe recommended practices will result in a net benefit to the environment and lead... portable fuel tanks to these new requirements, manufacturers working together on systems integration.... We have engaged the industry to identify a simple, safe, and emissions neutral solution to this...

A Simple Laboratory Exercise for Ethanol Production by Immobilized Bakery Yeasts ("Saccharomyces Cerevisiae")

ERIC Educational Resources Information Center

Vullo, Diana L.; Wachsman, Monica B.

2005-01-01

This laboratory experiment was designed for Chemistry, Food Technology, Biology, and Chemical Engineering undergraduate students. This laboratory experience shows the advantages of immobilized bakery yeasts in ethanol production by alcoholic fermentation. The students were able to compare the ethanol production yields by free or calcium alginate…

Washing Off Polyurethane Foam Insulation

NASA Technical Reports Server (NTRS)

Burley, Richard K.; Fogel, Irving

1990-01-01

Jet of hot water removes material quickly and safely. Simple, environmentally sound technique found to remove polyurethane foam insulation from metal parts. Developed for (but not limited to) use during rebuilding of fuel system of Space Shuttle main engine, during which insulation must be removed for penetrant inspection of metal parts.

Mutation of SIMPLE in Charcot–Marie–Tooth 1C alters production of exosomes

PubMed Central

Zhu, Hong; Guariglia, Sara; Yu, Raymond Y. L.; Li, Wenjing; Brancho, Deborah; Peinado, Hector; Lyden, David; Salzer, James; Bennett, Craig; Chow, Chi-Wing

2013-01-01

Charcot–Marie–Tooth (CMT) disease is an inherited neurological disorder. Mutations in the small integral membrane protein of the lysosome/late endosome (SIMPLE) account for the rare autosomal-dominant demyelination in CMT1C patients. Understanding the molecular basis of CMT1C pathogenesis is impeded, in part, by perplexity about the role of SIMPLE, which is expressed in multiple cell types. Here we show that SIMPLE resides within the intraluminal vesicles of multivesicular bodies (MVBs) and inside exosomes, which are nanovesicles secreted extracellularly. Targeting of SIMPLE to exosomes is modulated by positive and negative regulatory motifs. We also find that expression of SIMPLE increases the number of exosomes and secretion of exosome proteins. We engineer a point mutation on the SIMPLE allele and generate a physiological mouse model that expresses CMT1C-mutated SIMPLE at the endogenous level. We find that CMT1C mouse primary embryonic fibroblasts show decreased number of exosomes and reduced secretion of exosome proteins, in part due to improper formation of MVBs. CMT1C patient B cells and CMT1C mouse primary Schwann cells show similar defects. Together the data indicate that SIMPLE regulates the production of exosomes by modulating the formation of MVBs. Dysregulated endosomal trafficking and changes in the landscape of exosome-mediated intercellular communications may place an overwhelming burden on the nervous system and account for CMT1C molecular pathogenesis. PMID:23576546

Biofilm development in fixed bed biofilm reactors: experiments and simple models for engineering design purposes.

PubMed

Szilágyi, N; Kovács, R; Kenyeres, I; Csikor, Zs

2013-01-01

Biofilm development in a fixed bed biofilm reactor system performing municipal wastewater treatment was monitored aiming at accumulating colonization and maximum biofilm mass data usable in engineering practice for process design purposes. Initially a 6 month experimental period was selected for investigations where the biofilm formation and the performance of the reactors were monitored. The results were analyzed by two methods: for simple, steady-state process design purposes the maximum biofilm mass on carriers versus influent load and a time constant of the biofilm growth were determined, whereas for design approaches using dynamic models a simple biofilm mass prediction model including attachment and detachment mechanisms was selected and fitted to the experimental data. According to a detailed statistical analysis, the collected data have not allowed us to determine both the time constant of biofilm growth and the maximum biofilm mass on carriers at the same time. The observed maximum biofilm mass could be determined with a reasonable error and ranged between 438 gTS/m(2) carrier surface and 843 gTS/m(2), depending on influent load, and hydrodynamic conditions. The parallel analysis of the attachment-detachment model showed that the experimental data set allowed us to determine the attachment rate coefficient which was in the range of 0.05-0.4 m d(-1) depending on influent load and hydrodynamic conditions.

The influence of mixture preparation in the intake port on the performance of a spark-ignited four-stroke engine

NASA Astrophysics Data System (ADS)

Daniels, Charles Howard

An experimental technique is developed for evaluating the influence of mixture preparation in the intake port on the performance of a spark ignited engine. The preparation components studied are fuel vapor, droplets, and liquid streams. The fuel in these three distinct forms are produced and varied in a specially designed mixture preparation system, which delivers an air/fuel mixture to a test cylinder of an engine. Incorporated in the preparation system are devices for measuring the flow rates of fuel in these forms. A method of estimating the vapor concentration of a gasoline in the preparation channel by the use of simple temperature measurements is also presented. The effect of these fuel forms on in-cylinder pressure performance and exhaust gas concentrations are investigated in a 1.9 L Ford engine. A matrix of engine operations are studied along with two gasolines of different volatilities. The results of this investigation show that the operation of the engine at low speeds and low manifold absolute pressures is most susceptible to the effects mixture preparation. For those engine operating conditions affected, the results show that by increasing the amount of fuel in liquid stream form, the performance of the engine is generally diminished. In addition, 'equivalent' mixtures resulting from a conventional injector and a pneumatic atomizer in the intake port are identified relative to engine performance.

A study of performance and cost improvement potential of the 120 inch (3.05 m) diameter solid rocket motor. Volume 1: Summary report

NASA Technical Reports Server (NTRS)

Backlund, S. J.; Rossen, J. N.

1971-01-01

A parametric study of ballistic modifications to the 120 inch diameter solid propellant rocket engine which forms part of the Air Force Titan 3 system is presented. 576 separate designs were defined and 24 were selected for detailed analysis. Detailed design descriptions, ballistic performance, and mass property data were prepared for each design. It was determined that a relatively simple change in design parameters could provide a wide range of solid propellant rocket engine ballistic characteristics for future launch vehicle applications.

Overview of Rotating Cavitation and Cavitation Surge in the Fastrac Engine LOX Turbopump

NASA Technical Reports Server (NTRS)

Zoladz, Thomas; Turner, Jim (Technical Monitor)

2001-01-01

Observations regarding rotating cavitation and cavitation surge experienced during the development of the Fastrac 60 Klbf engine turbopump are discussed. Detailed observations from the analysis of both water flow and liquid oxygen test data are offered. Scaling and general comparison of rotating cavitation between water flow and liquid oxygen testing are discussed. Complex data features linking the localized rotating cavitation mechanism of the inducer to system surge components are described in detail. Finally a description of a simple lumped-parameter hydraulic system model developed to better understand observed data is given.

Biofuels from E. Coli: Engineering E. coli as an Electrofuels Chassis for Isooctane Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-07-16

Electrofuels Project: Ginkgo Bioworks is bypassing photosynthesis and engineering E. coli to directly use carbon dioxide (CO2) to produce biofuels. E. coli doesn’t naturally metabolize CO2, but Ginkgo Bioworks is manipulating and incorporating the genes responsible for CO2 metabolism into the microorganism. By genetically modifying E. coli, Ginkgo Bioworks will enhance its rate of CO2 consumption and liquid fuel production. Ginkgo Bioworks is delivering CO2 to E. coli as formic acid, a simple industrial chemical that provides energy and CO2 to the bacterial system.

Fuzzy Logic-Based Audio Pattern Recognition

NASA Astrophysics Data System (ADS)

Malcangi, M.

2008-11-01

Audio and audio-pattern recognition is becoming one of the most important technologies to automatically control embedded systems. Fuzzy logic may be the most important enabling methodology due to its ability to rapidly and economically model such application. An audio and audio-pattern recognition engine based on fuzzy logic has been developed for use in very low-cost and deeply embedded systems to automate human-to-machine and machine-to-machine interaction. This engine consists of simple digital signal-processing algorithms for feature extraction and normalization, and a set of pattern-recognition rules manually tuned or automatically tuned by a self-learning process.

Active Narrow-Band Vibration Isolation of Large Engineering Structures

NASA Technical Reports Server (NTRS)

Rahman, Zahidul; Spanos, John

1994-01-01

We present a narrow-band tracking control method using a variant of the Least Mean Squares (LMS) algorithm to isolate slowly changing periodic disturbances from engineering structures. The advantage of the algorithm is that it has a simple architecture and is relatively easy to implement while it can isolate disturbances on the order of 40-50 dB over decades of frequency band. We also present the results of an experiment conducted on a flexible truss structure. The average disturbance rejection achieved is over 40 dB over the frequency band of 5 Hz to 50 Hz.

100 Successful Years of Vertical Lift Gates of Bhatghar Dam—Design, Manufacturing, Erection, and Maintenance: A Case Study

NASA Astrophysics Data System (ADS)

Mahajan, Dinakar Rajaram

2017-09-01

The Bhatghar dam is having 81 vertical lift gates (fixed wheel type) on waste ways. The design of these gates is so beautiful and based on simple principles of science and engineering that these gates outlast for 100 years without failure, performing their intended purpose satisfactorily. It is achieved by meticulous design, manufacturing, erection, subsequent use and maintenance practices. It has become guiding and inspiration for further practices in design, manufacturing, erection, and maintenance for dam gates as well as all other disciplines of engineering today.

Maximum efficiency of ideal heat engines based on a small system: correction to the Carnot efficiency at the nanoscale.

PubMed

Quan, H T

2014-06-01

We study the maximum efficiency of a heat engine based on a small system. It is revealed that due to the finiteness of the system, irreversibility may arise when the working substance contacts with a heat reservoir. As a result, there is a working-substance-dependent correction to the Carnot efficiency. We derive a general and simple expression for the maximum efficiency of a Carnot cycle heat engine in terms of the relative entropy. This maximum efficiency approaches the Carnot efficiency asymptotically when the size of the working substance increases to the thermodynamic limit. Our study extends Carnot's result of the maximum efficiency to an arbitrary working substance and elucidates the subtlety of thermodynamic laws in small systems.

Engineering solutions to ureteral stents: material, coating and design

PubMed Central

Mosayyebi, Ali; Vijayakumar, Aravinthan; Yue, Qi Y.; Bres-Niewada, Ewa; Manes, Costantino; Carugo, Dario

2017-01-01

Introduction An ideal stent would offer simple insertion and removal with no discomfort and/or migration, it would have no biofilm formation or encrustation and would also maintain the patient's quality of life. Material and methods In this mini-review, we outlined the engineering developments related to stent material, design and coating. Results There have been a wide variety of in-vitro, model-based, animal-based and clinical studies using a range of commercial and non-commercial stents. Ureteric stents have evolved since their first usage with a wider range of stent design, material and coating available for laboratory and clinical use. Conclusions While engineering innovations have led to the evolution of stents, more work needs to be done to address the issues relating to stent encrustation and biofilm formation. PMID:29104790

Metrics in method engineering

NASA Astrophysics Data System (ADS)

Brinkkemper, S.; Rossi, M.

1994-12-01

As customizable computer aided software engineering (CASE) tools, or CASE shells, have been introduced in academia and industry, there has been a growing interest into the systematic construction of methods and their support environments, i.e. method engineering. To aid the method developers and method selectors in their tasks, we propose two sets of metrics, which measure the complexity of diagrammatic specification techniques on the one hand, and of complete systems development methods on the other hand. Proposed metrics provide a relatively fast and simple way to analyze the technique (or method) properties, and when accompanied with other selection criteria, can be used for estimating the cost of learning the technique and the relative complexity of a technique compared to others. To demonstrate the applicability of the proposed metrics, we have applied them to 34 techniques and 15 methods.

A reflection mechanism for aft fan tone noise from turbofan engines

NASA Astrophysics Data System (ADS)

Topol, D. A.; Holhubner, S. C.; Mathews, D. C.

1987-10-01

A fan tone noise mechanism is proposed which results from reflections from the fan of forward propagating rotor wake/fan exit guide vane interaction tone noise. These fan noise tones are often more dominant out of the rear than out of the front of an engine. To simulate this effect a simple qualitative prediction model was formulated and a scaled model test program was conducted. Results from each of these investigations are compared with each other and with full-scale engine data. These comparisons substantiate the potential importance of this mechanism. Further support is provided by mode measurement data from full-scale testing. This study concluded that for certain vane/blade ratios and tip Mach numbers the contribution of the reflection noise mechanism is significant.

Tissue Engineering the Cornea: The Evolution of RAFT

PubMed Central

Levis, Hannah J.; Kureshi, Alvena K.; Massie, Isobel; Morgan, Louise; Vernon, Amanda J.; Daniels, Julie T.

2015-01-01

Corneal blindness affects over 10 million people worldwide and current treatment strategies often involve replacement of the defective layer with healthy tissue. Due to a worldwide donor cornea shortage and the absence of suitable biological scaffolds, recent research has focused on the development of tissue engineering techniques to create alternative therapies. This review will detail how we have refined the simple engineering technique of plastic compression of collagen to a process we now call Real Architecture for 3D Tissues (RAFT). The RAFT production process has been standardised, and steps have been taken to consider Good Manufacturing Practice compliance. The evolution of this process has allowed us to create biomimetic epithelial and endothelial tissue equivalents suitable for transplantation and ideal for studying cell-cell interactions in vitro. PMID:25809689

Optimization of yeast-based production of medicinal protoberberine alkaloids.

PubMed

Galanie, Stephanie; Smolke, Christina D

2015-09-16

Protoberberine alkaloids are bioactive molecules abundant in plant preparations for traditional medicines. Yeast engineered to express biosynthetic pathways for fermentative production of these compounds will further enable investigation of the medicinal properties of these molecules and development of alkaloid-based drugs with improved efficacy and safety. Here, we describe the optimization of a biosynthetic pathway in Saccharomyces cerevisiae for conversion of rac-norlaudanosoline to the protoberberine alkaloid (S)-canadine. This yeast strain is engineered to express seven heterologous enzymes, resulting in protoberberine alkaloid production from a simple benzylisoquinoline alkaloid precursor. The seven enzymes include three membrane-bound enzymes: the flavin-dependent oxidase berberine bridge enzyme, the cytochrome P450 canadine synthase, and a cytochrome P450 reductase. A number of strategies were implemented to improve flux through the pathway, including enzyme variant screening, genetic copy number variation, and culture optimization, that led to an over 70-fold increase in canadine titer up to 1.8 mg/L. Increased canadine titers enable extension of the pathway to produce berberine, a major constituent of several traditional medicines, for the first time in a microbial host. We also demonstrate that this strain is viable at pilot scale. By applying metabolic engineering and synthetic biology strategies for increased conversion of simple benzylisoquinoline alkaloids to complex protoberberine alkaloids, this work will facilitate chemoenzymatic synthesis or de novo biosynthesis of these and other high-value compounds using a microbial cell factory.

A Simple Method for Amplifying RNA Targets (SMART)

PubMed Central

McCalla, Stephanie E.; Ong, Carmichael; Sarma, Aartik; Opal, Steven M.; Artenstein, Andrew W.; Tripathi, Anubhav

2012-01-01

We present a novel and simple method for amplifying RNA targets (named by its acronym, SMART), and for detection, using engineered amplification probes that overcome existing limitations of current RNA-based technologies. This system amplifies and detects optimal engineered ssDNA probes that hybridize to target RNA. The amplifiable probe-target RNA complex is captured on magnetic beads using a sequence-specific capture probe and is separated from unbound probe using a novel microfluidic technique. Hybridization sequences are not constrained as they are in conventional target-amplification reactions such as nucleic acid sequence amplification (NASBA). Our engineered ssDNA probe was amplified both off-chip and in a microchip reservoir at the end of the separation microchannel using isothermal NASBA. Optimal solution conditions for ssDNA amplification were investigated. Although KCl and MgCl2 are typically found in NASBA reactions, replacing 70 mmol/L of the 82 mmol/L total chloride ions with acetate resulted in optimal reaction conditions, particularly for low but clinically relevant probe concentrations (≤100 fmol/L). With the optimal probe design and solution conditions, we also successfully removed the initial heating step of NASBA, thus achieving a true isothermal reaction. The SMART assay using a synthetic model influenza DNA target sequence served as a fundamental demonstration of the efficacy of the capture and microfluidic separation system, thus bridging our system to a clinically relevant detection problem. PMID:22691910

Theoretical and experimental study on fiber-optic displacement sensor with bowknot bending modulation

NASA Astrophysics Data System (ADS)

Zheng, Yong; Huang, Da; Zhu, Zheng-Wei

2018-03-01

A novel and simple fiber-optic sensor for measuring a large displacement range in civil engineering has been developed. The sensor incorporates an extremely simple bowknot bending modulation that increases its sensitivity in bending, light source and detector. In this paper, to better understand the working principle and improve the performance of the sensor, the transduction of displacement to light loss is described analytically by using the geometry of sensor and principle of optical fiber loss. Results of the calibration tests show a logarithmic function relationship between light loss and displacement with two calibrated parameters. The sensor has a response over a wide displacement range of 44.7 mm with an initial accuracy of 2.65 mm, while for a small displacement range of 34 mm it shows a more excellent accuracy of 0.98 mm. The direct shear tests for the six models with the same dimensions were conducted to investigate the application of the sensor for warning the shear and sliding failure in civil engineering materials or geo-materials. Results address that the sliding displacement of sliding body can be relatively accurately captured by the theory logarithmic relation between sliding distance and optical loss in a definite structure, having a large dynamic range of 22.32 mm with an accuracy of 0.99 mm, which suggests that the sensor has a promising prospect in monitoring civil engineering, especially for landslides.

Cardiovascular tissue engineering: where we come from and where are we now?

PubMed

Smit, Francis E; Dohmen, Pascal M

2015-01-27

Abstract Tissue engineering was introduced by Vacanti and Langer in the 80's, exploring the potential of this new technology starting with the well-known "human ear on the mouse back". The goal is to create a substitute which supplies an individual therapy for patients with regeneration, remodeling and growth potential. The growth potential of these subjects is of special interest in congenital cardiac surgery, avoiding repeated interventions and surgery. Initial applications of tissue engineered created substitutes were relatively simple cardiovascular grafts seeded initially by end-differentiated autologous endothelial cells. Important data were collected from these initial clinical autologous endothelial cell seeded grafts in peripheral and coronary vessel disease. After these initial successfully implantation bone marrow cell were used to seed patches and pulmonary conduits were implanted in patients. Driven by the positive results of tissue engineered material implanted under low pressure circumstances, first tissue engineered patches were implanted in the systemic circulation followed by the implantation of tissue engineered aortic heart valves. Tissue engineering is an extreme dynamic technology with continuously modifications and improvements to optimize clinical products. New technologies are unified and so this has also be done with tissue engineering and new application features, so called transcatheter valve intervention. First studies are initiated to apply tissue engineered heart valves with this new transcatheter delivery system less invasive. Simultaneously studies have been started on tissue engineering of so-called whole organs since organ transplantation is restricted due to donor shortage and tissue engineering could overcome this problem. Initial studies of whole heart engineering in the rat model are promising and larger size models are initiated.

SIRE: A Simple Interactive Rule Editor for NICBES

NASA Technical Reports Server (NTRS)

Bykat, Alex

1988-01-01

To support evolution of domain expertise, and its representation in an expert system knowledge base, a user-friendly rule base editor is mandatory. The Nickel Cadmium Battery Expert System (NICBES), a prototype of an expert system for the Hubble Space Telescope power storage management system, does not provide such an editor. In the following, a description of a Simple Interactive Rule Base Editor (SIRE) for NICBES is described. The SIRE provides a consistent internal representation of the NICBES knowledge base. It supports knowledge presentation and provides a user-friendly and code language independent medium for rule addition and modification. The SIRE is integrated with NICBES via an interface module. This module provides translation of the internal representation to Prolog-type rules (Horn clauses), latter rule assertion, and a simple mechanism for rule selection for its Prolog inference engine.

Toward unraveling the complexity of simple epithelial keratins in human disease.

PubMed

Omary, M Bishr; Ku, Nam-On; Strnad, Pavel; Hanada, Shinichiro

2009-07-01

Simple epithelial keratins (SEKs) are found primarily in single-layered simple epithelia and include keratin 7 (K7), K8, K18-K20, and K23. Genetically engineered mice that lack SEKs or overexpress mutant SEKs have helped illuminate several keratin functions and served as important disease models. Insight into the contribution of SEKs to human disease has indicated that K8 and K18 are the major constituents of Mallory-Denk bodies, hepatic inclusions associated with several liver diseases, and are essential for inclusion formation. Furthermore, mutations in the genes encoding K8, K18, and K19 predispose individuals to a variety of liver diseases. Hence, as we discuss here, the SEK cytoskeleton is involved in the orchestration of several important cellular functions and contributes to the pathogenesis of human liver disease.

Toward unraveling the complexity of simple epithelial keratins in human disease

PubMed Central

Omary, M. Bishr; Ku, Nam-On; Strnad, Pavel; Hanada, Shinichiro

2009-01-01

Simple epithelial keratins (SEKs) are found primarily in single-layered simple epithelia and include keratin 7 (K7), K8, K18–K20, and K23. Genetically engineered mice that lack SEKs or overexpress mutant SEKs have helped illuminate several keratin functions and served as important disease models. Insight into the contribution of SEKs to human disease has indicated that K8 and K18 are the major constituents of Mallory-Denk bodies, hepatic inclusions associated with several liver diseases, and are essential for inclusion formation. Furthermore, mutations in the genes encoding K8, K18, and K19 predispose individuals to a variety of liver diseases. Hence, as we discuss here, the SEK cytoskeleton is involved in the orchestration of several important cellular functions and contributes to the pathogenesis of human liver disease. PMID:19587454

Comparison of human driver dynamics in simulators with complex and simple visual displays and in an automobile on the road

NASA Technical Reports Server (NTRS)

Mcruer, D. T.; Klein, R. H.

1975-01-01

As part of a comprehensive program exploring driver/vehicle system response in lateral steering tasks, driver/vehicle system describing functions and other dynamic data have been gathered in several milieu. These include a simple fixed base simulator with an elementary roadway delineation only display; a fixed base statically operating automobile with a terrain model based, wide angle projection system display; and a full scale moving base automobile operating on the road. Dynamic data with the two fixed base simulators compared favorably, implying that the impoverished visual scene, lack of engine noise, and simplified steering wheel feel characteristics in the simple simulator did not induce significant driver dynamic behavior variations. The fixed base vs. moving base comparisons showed substantially greater crossover frequencies and phase margins on the road course.

The Combination of Internal-Combustion Engine and Gas Turbine

NASA Technical Reports Server (NTRS)

Zinner, K.

1947-01-01

While the gas turbine by itself has been applied in particular cases for power generation and is in a state of promising development in this field, it has already met with considerable success in two cases when used as an exhaust turbine in connection with a centrifugal compressor, namely, in the supercharging of combustion engines and in the Velox process, which is of particular application for furnaces. In the present paper the most important possibilities of combining a combustion engine with a gas turbine are considered. These "combination engines " are compared with the simple gas turbine on whose state of development a brief review will first be given. The critical evaluation of the possibilities of development and fields of application of the various combustion engine systems, wherever it is not clearly expressed in the publications referred to, represents the opinion of the author. The state of development of the internal-combustion engine is in its main features generally known. It is used predominantly at the present time for the propulsion of aircraft and road vehicles and, except for certain restrictions due to war conditions, has been used to an increasing extent in ships and rail cars and in some fields applied as stationary power generators. In the Diesel engine a most economical heat engine with a useful efficiency of about 40 percent exists and in the Otto aircraft engine a heat engine of greatest power per unit weight of about 0.5 kilogram per horsepower.

Engineering graphics data entry for space station data base

NASA Technical Reports Server (NTRS)

Lacovara, R. C.

1986-01-01

The entry of graphical engineering data into the Space Station Data Base was examined. Discussed were: representation of graphics objects; representation of connectivity data; graphics capture hardware; graphics display hardware; site-wide distribution of graphics, and consolidation of tools and hardware. A fundamental assumption was that existing equipment such as IBM based graphics capture software and VAX networked facilities would be exploited. Defensible conclusions reached after study and simulations of use of these systems at the engineering level are: (1) existing IBM based graphics capture software is an adequate and economical means of entry of schematic and block diagram data for present and anticipated electronic systems for Space Station; (2) connectivity data from the aforementioned system may be incorporated into the envisioned Space Station Data Base with modest effort; (3) graphics and connectivity data captured on the IBM based system may be exported to the VAX network in a simple and direct fashion; (4) graphics data may be displayed site-wide on VT-125 terminals and lookalikes; (5) graphics hard-copy may be produced site-wide on various dot-matrix printers; and (6) the system may provide integrated engineering services at both the engineering and engineering management level.

An algorithm to estimate aircraft cruise black carbon emissions for use in developing a cruise emissions inventory.

PubMed

Peck, Jay; Oluwole, Oluwayemisi O; Wong, Hsi-Wu; Miake-Lye, Richard C

2013-03-01

To provide accurate input parameters to the large-scale global climate simulation models, an algorithm was developed to estimate the black carbon (BC) mass emission index for engines in the commercial fleet at cruise. Using a high-dimensional model representation (HDMR) global sensitivity analysis, relevant engine specification/operation parameters were ranked, and the most important parameters were selected. Simple algebraic formulas were then constructed based on those important parameters. The algorithm takes the cruise power (alternatively, fuel flow rate), altitude, and Mach number as inputs, and calculates BC emission index for a given engine/airframe combination using the engine property parameters, such as the smoke number, available in the International Civil Aviation Organization (ICAO) engine certification databank. The algorithm can be interfaced with state-of-the-art aircraft emissions inventory development tools, and will greatly improve the global climate simulations that currently use a single fleet average value for all airplanes. An algorithm to estimate the cruise condition black carbon emission index for commercial aircraft engines was developed. Using the ICAO certification data, the algorithm can evaluate the black carbon emission at given cruise altitude and speed.

Design feasibility via ascent optimality for next-generation spacecraft

NASA Astrophysics Data System (ADS)

Miele, A.; Mancuso, S.

This paper deals with the optimization of the ascent trajectories for single-stage-sub-orbit (SSSO), single-stage-to-orbit (SSTO), and two-stage-to-orbit (TSTO) rocket-powered spacecraft. The maximum payload weight problem is studied for different values of the engine specific impulse and spacecraft structural factor. The main conclusions are that: feasibility of SSSO spacecraft is guaranteed for all the parameter combinations considered; feasibility of SSTO spacecraft depends strongly on the parameter combination chosen; not only feasibility of TSTO spacecraft is guaranteed for all the parameter combinations considered, but the TSTO payload is several times the SSTO payload. Improvements in engine specific impulse and spacecraft structural factor are desirable and crucial for SSTO feasibility; indeed, aerodynamic improvements do not yield significant improvements in payload. For SSSO, SSTO, and TSTO spacecraft, simple engineering approximations are developed connecting the maximum payload weight to the engine specific impulse and spacecraft structural factor. With reference to the specific impulse/structural factor domain, these engineering approximations lead to the construction of zero-payload lines separating the feasibility region (positive payload) from the unfeasibility region (negative payload).

Intelligent Agents for Design and Synthesis Environments: My Summary

NASA Technical Reports Server (NTRS)

Norvig, Peter

1999-01-01

This presentation gives a summary of intelligent agents for design synthesis environments. We'll start with the conclusions, and work backwards to justify them. First, an important assumption is that agents (whatever they are) are good for software engineering. This is especially true for software that operates in an uncertain, changing environment. The "real world" of physical artifacts is like that: uncertain in what we can measure, changing in that things are always breaking down, and we must interact with non-software entities. The second point is that software engineering techniques can contribute to good design. There may have been a time when we wanted to build simple artifacts containing little or no software. But modern aircraft and spacecraft are complex, and rely on a great deal of software. So better software engineering leads to better designed artifacts, especially when we are designing a series of related artifacts and can amortize the costs of software development. The third point is that agents are especially useful for design tasks, above and beyond their general usefulness for software engineering, and the usefulness of software engineering to design.

Motion-base simulator study of control of an externally blown flap STOL transport aircraft after failure of an outboard engine during landing approach

NASA Technical Reports Server (NTRS)

Middleton, D. B.; Hurt, G. J., Jr.; Bergeron, H. P.; Patton, J. M., Jr.; Deal, P. L.; Champine, R. A.

1975-01-01

A moving-base simulator investigation of the problems of recovery and landing of a STOL aircraft after failure of an outboard engine during final approach was made. The approaches were made at 75 knots along a 6 deg glide slope. The engine was failed at low altitude and the option to go around was not allowed. The aircraft was simulated with each of three control systems, and it had four high-bypass-ratio fan-jet engines exhausting against large triple-slotted wing flaps to produce additional lift. A virtual-image out-the-window television display of a simulated STOL airport was operating during part of the investigation. Also, a simple heads-up flight director display superimposed on the airport landing scene was used by the pilots to make some of the recoveries following an engine failure. The results of the study indicated that the variation in visual cues and/or motion cues had little effect on the outcome of a recovery, but they did have some effect on the pilot's response and control patterns.

Utilization of biodiesel by-product as substrate for high-production of β-farnesene via relatively balanced mevalonate pathway in Escherichia coli.

PubMed

You, Shengping; Yin, Qingdian; Zhang, Jianye; Zhang, Chengyu; Qi, Wei; Gao, Lan; Tao, Zhiping; Su, Rongxin; He, Zhimin

2017-11-01

Farnesene has been identified as suitable jet fuel substitutes and metabolic engineering for microbial production of farnesene is an alternative and attractive route. In this study, due to accumulation of toxic intermediate isopentenyl pyrophosphate (IPP), an engineered Escherichia coli strain harboring heterologous mevalonate pathway produced only 4.11mg/L β-farnesene. Through higher-level expression of isopentenyl diphosphate isomerase and farnesyl diphosphate synthase to minimize the accumulated IPP, another engineered strain with relatively balanced mevalonate pathway was constructed and had the highest production of β-farnesene to date (8.74g/L) by Escherichia coli in a lab bioreactor. Furthermore, this is the first report on utilization of biodiesel by-product (simple purification) as substrate for high-production of β-farnesene by the engineered strain optimized and β-farnesene concentration reached 2.83g/L in a lab bioreactor. Therefore, the engineered strain optimized could be used as a platform host for high-production of other terpenoids using biodiesel by-product as substrate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Treb-Bot: Development and Use of a Trebuchet Simulator

ERIC Educational Resources Information Center

Constans, Eric; Constans, Aileen

2015-01-01

The trebuchet has quickly become a favorite project for physics and engineering teachers seeking to provide students with a simple, but spectacular, hands-on design project that can be applied to the study of projectile motion, rotational motion, and the law of conservation of energy. While there have been free trebuchet simulators and range…

Physics and biochemical engineering: 3

NASA Astrophysics Data System (ADS)

Fairbrother, Robert; Riddle, Wendy; Fairbrother, Neil

2006-09-01

Once an antibiotic has been produced on a large scale, as described in our preceding articles, it has to be extracted and purified. Filtration and centrifugation are the two main ways of doing this, and the design of industrial processing systems is governed by simple physics involving factors such as pressure, viscosity and rotational motion.

A Simple Algorithm for Obtaining Nearly Optimal Quadrature Rules for NURBS-based Isogeometric Analysis

DTIC Science & Technology

2012-01-05

Università degli Studi di Pavia bIstituto di Matematica Applicata e Tecnologie Informatiche “E. Magenes” del CNR, Pavia cDAEIMI, Università degli Studi di...Cassino d Institute for Computational Engineering and Sciences, University of Texas at Austin eDipartimento di Matematica , Università degli Studi di

Visualizing Gas Adsorption on Porous Solids: Four Simple, Effective Demonstrations

ERIC Educational Resources Information Center

Cheung, Ocean

2014-01-01

Gas adsorption on porous solids is a topic that is often discussed in an undergraduate chemistry or chemical engineering course. The idea of porosity and gas adsorption on a porous solid is usually discussed with adsorption isotherms recorded using commercially available equipment. This discussion can be rather abstract and can be difficult for…

Exploring Google to Enhance Reference Services

ERIC Educational Resources Information Center

Jia, Peijun

2011-01-01

Google is currently recognized as the world's most powerful search engine. Google is so powerful and intuitive that one does not need to possess many skills to use it. However, Google is more than just simple search. For those who have special search skills and know Google's superior search features, it becomes an extraordinary tool. To understand…

The Legacy Project

ERIC Educational Resources Information Center

Moye, Johnny J.

2012-01-01

This article is the first in a series of articles entitled "The Legacy Project." It focuses on the lives and actions of leaders who have forged technology engineering education profession into what it is today. Members of the profession owe a debt of gratitude to these leaders. One simple way to demonstrate that gratitude is to recognize them and…

On Parallel Software Engineering Education Using Python

ERIC Educational Resources Information Center

Marowka, Ami

2018-01-01

Python is gaining popularity in academia as the preferred language to teach novices serial programming. The syntax of Python is clean, easy, and simple to understand. At the same time, it is a high-level programming language that supports multi programming paradigms such as imperative, functional, and object-oriented. Therefore, by default, it is…

Blame It on the Engineers

ERIC Educational Resources Information Center

Roman, Harry T.

2004-01-01

The nation's industrial revolution began after the Civil War. Thomas Edison codified the simple and repeatable process of invention, and off the country went on an inventive joy ride that shows no sign of letting up. Undoubtedly, Edison's greatest invention was the process of industrial research, for equipped with it people can make products and…

Towards a more plausible dragon

NASA Astrophysics Data System (ADS)

Efthimiou, Costas

2014-08-01

Wizards, mermaids, dragons and aliens. Walking, running, flying and space travel. A hi-tech elevator, a computer, a propulsion engine and a black hole. What do all of these things have in common? This might seem like a really hard brainteaser but the answer is simple: they all obey the fundamental laws of our universe.

Engineering Paper-Based Sensors for Zika Virus

DOE PAGES

Meagher, Robert J.; Negrete, Oscar A.; Van Rompay, Koen K.

2016-05-30

The emergence of Zika virus in Latin America has created an urgent need for new, simple yet sensitive diagnostic tests. We highlight recent work using paper-based sensors coupled with CRISPR/Cas9 to detect Zika RNA, as a new approach to rapid development and deployment of field-ready diagnostics for emerging infectious diseases.

Engineering Paper-Based Sensors for Zika Virus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meagher, Robert J.; Negrete, Oscar A.; Van Rompay, Koen K.

The emergence of Zika virus in Latin America has created an urgent need for new, simple yet sensitive diagnostic tests. We highlight recent work using paper-based sensors coupled with CRISPR/Cas9 to detect Zika RNA, as a new approach to rapid development and deployment of field-ready diagnostics for emerging infectious diseases.

Teacher workshop

NASA Image and Video Library

2012-10-20

The John C. Stennis Space Center Educator Resource Center hosted an Oct. 20 workshop to equip teachers of grades 3 through 12 in using the LEGO Bricks in Space curriculum issued by NASA. Participants in the professional development workshop built their own LEGO simple machine prototypes and explored the engineering principles that make them work (on Earth and in space).

The Second Law of Thermodynamics in a Historical Setting.

ERIC Educational Resources Information Center

Strnad, J.

1984-01-01

Traces the development of thermodynamics in physics, focusing on a strategy which enables students to grasp in a limited time and by means of simple calculus the main implications of the second law essential for everyday life (understanding operation of heat engines, refrigerators, heat pumps, district heating, and energy degradation). (JN)

Re-Engineering the United States Marine Corps Special Education Program (SEP).

DTIC Science & Technology

1998-03-01

McDonald’s or Burger King based on personal preference. This simple decision has only two alternatives and relatively low consequences (the decision...In the example of restaurants seen above, a person would not be able to examine 2000 different franchises and select the best one in which to invest

Nano-Engineering of Active Metamaterials

DTIC Science & Technology

2014-10-29

simulation of linear and nonlinear optical properties and dielectric permittivity including those of dipolar liquids, dendrimers , polymers, and...orders of magnitude with simple variation of chromophore structure. Note that chromophores in dendrimers are usually more stable than the same...chromophore in polymer composites consistent with reduced oxygen accessability in the dendrimer material lattice. Lattice hardening (crosslinking) and

Integrated Thermal Modules for Cooling Silicon and Silicon Carbide Power Modules

DTIC Science & Technology

2007-06-11

analyses, bench tests, and motor tests comprise the program. The ITMs, in place of standard heatsinks, use a highly conductive pyrolytic graphite to...passively cool power modules. Initial results show that even simple ITMs can lower chip temperatures by 20 deg. C and 10 deg. C with engine oil and

Teaching Transport Phenomena around a Cup of Coffee

ERIC Educational Resources Information Center

Condoret, Jean Stephane

2007-01-01

The very common situation of waiting for the cooling of a cup of coffee is addressed through a conventional engineering approach, where several important concepts of heat and mass transfer are used. A numerical and analytical solution of the differential equations of the problem are proposed, and assessed by comparing to simple experiments.…

Computer Code Aids Design Of Wings

NASA Technical Reports Server (NTRS)

Carlson, Harry W.; Darden, Christine M.

1993-01-01

AERO2S computer code developed to aid design engineers in selection and evaluation of aerodynamically efficient wing/canard and wing/horizontal-tail configurations that includes simple hinged-flap systems. Code rapidly estimates longitudinal aerodynamic characteristics of conceptual airplane lifting-surface arrangements. Developed in FORTRAN V on CDC 6000 computer system, and ported to MS-DOS environment.

Whatever Floats Your Boat: A Design Challenge

ERIC Educational Resources Information Center

Kornoelje, Joanne; Roman, Harry T.

2012-01-01

This article presents a simple design challenge, based on the PBS program "Design Squad's" "Watercraft" activity that will prove engaging to most technology and engineering students. In this floating boat challenge, students are to build a boat that can float and support 25 pennies for at least 10 seconds--without leaking, sinking, or tipping…

Measuring Leakage From Large, Complicated Machinery

NASA Technical Reports Server (NTRS)

Bottemiller, S.

1987-01-01

Test chamber improvised from large bag. Cumulative sizes of leaks in large, complicated machinery measure with relatively simple variation of helium leak-checking technique. When used to check Space Shuttle main engine, new technique gave repeatable and correct results within 0.5 stdin.3/min (1.4 x 10 negative to the seventh power stdm3/s).

Implementation of Artificial Intelligence Assessment in Engineering Laboratory Education

ERIC Educational Resources Information Center

Samarakou, Maria; Fylladitakis, Emmanouil D.; Prentakis, Pantelis; Athineos, Spyros

2014-01-01

In laboratory courses, the assessment of exercises and assignments typically is treated as a simple, quantifiable approach. This approach however rarely includes qualitative factors, especially if the grading is being automatically performed by the system, and provides little to no feedback for the students to reflect on their work. The role of…

The three-hinged arch as an example of piezomechanic passive controlled structure

NASA Astrophysics Data System (ADS)

Pagnini, Luisa Carlotta; Piccardo, Giuseppe

2016-09-01

Although piezoelectric transducers are employed in a variety of fields, their application for vibration control of civil or industrial structures has not yet been fully developed, at the best of authors' knowledge. Thanks to a new generation of ever more performing piezoceramic materials and to the recent development of scientific proposals based on a very simple technology, this paper presents a step forward to engineering applications for the control of structural systems. A three-hinged arch controlled by piezoelectric stack actuators and passive RL electrical circuits is chosen as a simple structural model that may represent the starting point for a generalization to the most common typologies of civil and industrial engineering structures. Based on the concept of electromechanical analogy, the evolution equations are obtained through a consistent Lagrangian approach. A multimodal vibration suppression is guaranteed by the spectral analogy between the mechanical and electrical components. Preliminary applications related to free oscillations, with one or more actuators on each member, seem to lead to excellent performance in terms of multimodal damping and dissipated energy.

GGRNA: an ultrafast, transcript-oriented search engine for genes and transcripts

PubMed Central

Naito, Yuki; Bono, Hidemasa

2012-01-01

GGRNA (http://GGRNA.dbcls.jp/) is a Google-like, ultrafast search engine for genes and transcripts. The web server accepts arbitrary words and phrases, such as gene names, IDs, gene descriptions, annotations of gene and even nucleotide/amino acid sequences through one simple search box, and quickly returns relevant RefSeq transcripts. A typical search takes just a few seconds, which dramatically enhances the usability of routine searching. In particular, GGRNA can search sequences as short as 10 nt or 4 amino acids, which cannot be handled easily by popular sequence analysis tools. Nucleotide sequences can be searched allowing up to three mismatches, or the query sequences may contain degenerate nucleotide codes (e.g. N, R, Y, S). Furthermore, Gene Ontology annotations, Enzyme Commission numbers and probe sequences of catalog microarrays are also incorporated into GGRNA, which may help users to conduct searches by various types of keywords. GGRNA web server will provide a simple and powerful interface for finding genes and transcripts for a wide range of users. All services at GGRNA are provided free of charge to all users. PMID:22641850

GGRNA: an ultrafast, transcript-oriented search engine for genes and transcripts.

PubMed

Naito, Yuki; Bono, Hidemasa

2012-07-01

GGRNA (http://GGRNA.dbcls.jp/) is a Google-like, ultrafast search engine for genes and transcripts. The web server accepts arbitrary words and phrases, such as gene names, IDs, gene descriptions, annotations of gene and even nucleotide/amino acid sequences through one simple search box, and quickly returns relevant RefSeq transcripts. A typical search takes just a few seconds, which dramatically enhances the usability of routine searching. In particular, GGRNA can search sequences as short as 10 nt or 4 amino acids, which cannot be handled easily by popular sequence analysis tools. Nucleotide sequences can be searched allowing up to three mismatches, or the query sequences may contain degenerate nucleotide codes (e.g. N, R, Y, S). Furthermore, Gene Ontology annotations, Enzyme Commission numbers and probe sequences of catalog microarrays are also incorporated into GGRNA, which may help users to conduct searches by various types of keywords. GGRNA web server will provide a simple and powerful interface for finding genes and transcripts for a wide range of users. All services at GGRNA are provided free of charge to all users.

Structural dynamics and vibrations of damped, aircraft-type structures

NASA Technical Reports Server (NTRS)

Young, Maurice I.

1992-01-01

Engineering preliminary design methods for approximating and predicting the effects of viscous or equivalent viscous-type damping treatments on the free and forced vibration of lightly damped aircraft-type structures are developed. Similar developments are presented for dynamic hysteresis viscoelastic-type damping treatments. It is shown by both engineering analysis and numerical illustrations that the intermodal coupling of the undamped modes arising from the introduction of damping may be neglected in applying these preliminary design methods, except when dissimilar modes of these lightly damped, complex aircraft-type structures have identical or nearly identical natural frequencies. In such cases, it is shown that a relatively simple, additional interaction calculation between pairs of modes exhibiting this 'modal response' phenomenon suffices in the prediction of interacting modal damping fractions. The accuracy of the methods is shown to be very good to excellent, depending on the normal natural frequency separation of the system modes, thereby permitting a relatively simple preliminary design approach. This approach is shown to be a natural precursor to elaborate finite element, digital computer design computations in evaluating the type, quantity, and location of damping treatment.

The shape of cars to come

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ashley, S.

1991-05-01

Ford's new concept car achieves weight, size, and cost savings with an innovative lightweight aluminum space frame composed of simple extrusions that are fitted together like Lego blocks and adhesively bonded. On the outside, the design is a blend of art and technology that is a modern restatement of a large luxury car. The other major focus of the design is the Contour's compact T-drive powertrain configuration (also shared by the Mystique). This consists of a transversely mounted engine stuffed into the front of the chassis with a longitudinally positioned transmission right behind it. The T-drive arrangement shrinks the car'smore » engine bay and overall length while expanding the passenger compartment. In addition, powerplants with from four to eight cylinders as well as front-wheel-, rear-wheel-, and four-wheel-drive transmission systems can all be incorporated into the T-drive. Other technical innovations on the Contour include an unusual ducted cooling system, a compact brake assembly, a lightweight high-efficiency air conditioner, centralized single-source lighting, and simple but effective suspension technology.« less

Self-Assembled Nanoporous Biofilms from Functionalized Nanofibrous M13 Bacteriophage.

PubMed

Devaraj, Vasanthan; Han, Jiye; Kim, Chuntae; Kang, Yong-Cheol; Oh, Jin-Woo

2018-06-12

Highly periodic and uniform nanostructures, based on a genetically engineered M13 bacteriophage, displayed unique properties at the nanoscale that have the potential for a variety of applications. In this work, we report a multilayer biofilm with self-assembled nanoporous surfaces involving a nanofiber-like genetically engineered 4E-type M13 bacteriophage, which was fabricated using a simple pulling method. The nanoporous surfaces were effectively formed by using the networking-like structural layers of the M13 bacteriophage during self-assembly. Therefore, an external template was not required. The actual M13 bacteriophage-based fabricated multilayered biofilm with porous nanostructures agreed well with experimental and simulation results. Pores formed in the final layer had a diameter of about 150⁻500 nm and a depth of about 15⁻30 nm. We outline a filter application for this multilayered biofilm that enables selected ions to be extracted from a sodium chloride solution. Here, we describe a simple, environmentally friendly, and inexpensive fabrication approach with large-scale production potential. The technique and the multi-layered biofilms produced may be applied to sensor, filter, plasmonics, and bio-mimetic fields.

Design principles of hair-like structures as biological machines

PubMed Central

2018-01-01

Hair-like structures are prevalent throughout biology and frequently act to sense or alter interactions with an organism's environment. The overall shape of a hair is simple: a long, filamentous object that protrudes from the surface of an organism. This basic design, however, can confer a wide range of functions, owing largely to the flexibility and large surface area that it usually possesses. From this simple structural basis, small changes in geometry, such as diameter, curvature and inter-hair spacing, can have considerable effects on mechanical properties, allowing functions such as mechanosensing, attachment, movement and protection. Here, we explore how passive features of hair-like structures, both individually and within arrays, enable diverse functions across biology. Understanding the relationships between form and function can provide biologists with an appreciation for the constraints and possibilities on hair-like structures. Additionally, such structures have already been used in biomimetic engineering with applications in sensing, water capture and adhesion. By examining hairs as a functional mechanical unit, geometry and arrangement can be rationally designed to generate new engineering devices and ideas. PMID:29848593

Smart actuation of inlet guide vanes for small turbine engine

NASA Astrophysics Data System (ADS)

Rusovici, Razvan; Kwok Choon, Stephen T.; Sepri, Paavo; Feys, Joshuo

2011-04-01

Unmanned Aerial Vehicles (UAVs) have gained popularity over the past few years to become an indispensable part of aerial missions that include reconnaissance, surveillance, and communication [1]. As a result, advancements in small jet-engine performance are needed to increase the performance (range, payload and efficiency) of the UAV. These jet engines designed especially for UAV's are characterized by thrust force on the order of 100N and due to their size and weight limitations, may lack advanced flow control devices such as IGV [2]. The goal of the current study was to present a conceptual design of an IGV smart-material based actuation mechanism that would be simple, compact and lightweight. The compressor section of an engine increases the pressure and conditions the flow before the air enters the combustion chamber [3]. The airflow entering the compressor is often turbulent due to the high angle of incidence between engine inlet and free-stream velocity, or existing atmospheric turbulence. Actuated IGV are used to help control the relative angle of incidence of the flow that enters the engine compressor, thereby preventing flow separation, compressor stall and thus extending the compressor's operating envelope [4]. Turbine jet- engines which employ variable IGV were developed by Rolls Royce (Trent DR-900) and General Electric (J79).

Engineering E. coli–E. coli cocultures for production of muconic acid from glycerol

DOE PAGES

Zhang, Haoran; Li, Zhengjun; Pereira, Brian; ...

2015-09-15

cis, cis-Muconic acid is an important chemical that can be biosynthesized from simple substrates in engineered microorganisms. Recently, it has been shown that engineering microbial cocultures is an emerging and promising approach for biochemical production. In this study, we aim to explore the potential of the E. coli–E. coli coculture system to use a single renewable carbon source, glycerol, for the production of value-added product cis, cis-muconic acid. As a result, two coculture engineering strategies were investigated. In the first strategy, an E. coli strain containing the complete biosynthesis pathway was co-cultivated with another E. coli strain containing only amore » heterologous intermediate-to-product biosynthetic pathway. In the second strategy, the upstream and downstream pathways were accommodated in two separate E. coli strains, each of which was dedicated to one portion of the biosynthesis process. Compared with the monoculture approach, both coculture engineering strategies improved the production significantly. Using a batch bioreactor, the engineered coculture achieved a 2 g/L muconic acid production with a yield of 0.1 g/g. In conclusion, our results demonstrate that coculture engineering is a viable option for producing muconic acid from glycerol. Moreover, microbial coculture systems are shown to have the potential for converting single carbon source to value-added products.« less

Predicting Minimum Control Speed on the Ground (VMCG) and Minimum Control Airspeed (VMCA) of Engine Inoperative Flight Using Aerodynamic Database and Propulsion Database Generators

NASA Astrophysics Data System (ADS)

Hadder, Eric Michael

There are many computer aided engineering tools and software used by aerospace engineers to design and predict specific parameters of an airplane. These tools help a design engineer predict and calculate such parameters such as lift, drag, pitching moment, takeoff range, maximum takeoff weight, maximum flight range and much more. However, there are very limited ways to predict and calculate the minimum control speeds of an airplane in engine inoperative flight. There are simple solutions, as well as complicated solutions, yet there is neither standard technique nor consistency throughout the aerospace industry. To further complicate this subject, airplane designers have the option of using an Automatic Thrust Control System (ATCS), which directly alters the minimum control speeds of an airplane. This work addresses this issue with a tool used to predict and calculate the Minimum Control Speed on the Ground (VMCG) as well as the Minimum Control Airspeed (VMCA) of any existing or design-stage airplane. With simple line art of an airplane, a program called VORLAX is used to generate an aerodynamic database used to calculate the stability derivatives of an airplane. Using another program called Numerical Propulsion System Simulation (NPSS), a propulsion database is generated to use with the aerodynamic database to calculate both VMCG and VMCA. This tool was tested using two airplanes, the Airbus A320 and the Lockheed Martin C130J-30 Super Hercules. The A320 does not use an Automatic Thrust Control System (ATCS), whereas the C130J-30 does use an ATCS. The tool was able to properly calculate and match known values of VMCG and VMCA for both of the airplanes. The fact that this tool was able to calculate the known values of VMCG and VMCA for both airplanes means that this tool would be able to predict the VMCG and VMCA of an airplane in the preliminary stages of design. This would allow design engineers the ability to use an Automatic Thrust Control System (ATCS) as part of the design of an airplane and still have the ability to predict the VMCG and VMCA of the airplane.

Earth Science Mining Web Services

NASA Astrophysics Data System (ADS)

Pham, L. B.; Lynnes, C. S.; Hegde, M.; Graves, S.; Ramachandran, R.; Maskey, M.; Keiser, K.

2008-12-01

To allow scientists further capabilities in the area of data mining and web services, the Goddard Earth Sciences Data and Information Services Center (GES DISC) and researchers at the University of Alabama in Huntsville (UAH) have developed a system to mine data at the source without the need of network transfers. The system has been constructed by linking together several pre-existing technologies: the Simple Scalable Script-based Science Processor for Measurements (S4PM), a processing engine at the GES DISC; the Algorithm Development and Mining (ADaM) system, a data mining toolkit from UAH that can be configured in a variety of ways to create customized mining processes; ActiveBPEL, a workflow execution engine based on BPEL (Business Process Execution Language); XBaya, a graphical workflow composer; and the EOS Clearinghouse (ECHO). XBaya is used to construct an analysis workflow at UAH using ADaM components, which are also installed remotely at the GES DISC, wrapped as Web Services. The S4PM processing engine searches ECHO for data using space-time criteria, staging them to cache, allowing the ActiveBPEL engine to remotely orchestrates the processing workflow within S4PM. As mining is completed, the output is placed in an FTP holding area for the end user. The goals are to give users control over the data they want to process, while mining data at the data source using the server's resources rather than transferring the full volume over the internet. These diverse technologies have been infused into a functioning, distributed system with only minor changes to the underlying technologies. The key to this infusion is the loosely coupled, Web- Services based architecture: All of the participating components are accessible (one way or another) through (Simple Object Access Protocol) SOAP-based Web Services.

Synthetic biology: insights into biological computation.

PubMed

Manzoni, Romilde; Urrios, Arturo; Velazquez-Garcia, Silvia; de Nadal, Eulàlia; Posas, Francesc

2016-04-18

Organisms have evolved a broad array of complex signaling mechanisms that allow them to survive in a wide range of environmental conditions. They are able to sense external inputs and produce an output response by computing the information. Synthetic biology attempts to rationally engineer biological systems in order to perform desired functions. Our increasing understanding of biological systems guides this rational design, while the huge background in electronics for building circuits defines the methodology. In this context, biocomputation is the branch of synthetic biology aimed at implementing artificial computational devices using engineered biological motifs as building blocks. Biocomputational devices are defined as biological systems that are able to integrate inputs and return outputs following pre-determined rules. Over the last decade the number of available synthetic engineered devices has increased exponentially; simple and complex circuits have been built in bacteria, yeast and mammalian cells. These devices can manage and store information, take decisions based on past and present inputs, and even convert a transient signal into a sustained response. The field is experiencing a fast growth and every day it is easier to implement more complex biological functions. This is mainly due to advances in in vitro DNA synthesis, new genome editing tools, novel molecular cloning techniques, continuously growing part libraries as well as other technological advances. This allows that digital computation can now be engineered and implemented in biological systems. Simple logic gates can be implemented and connected to perform novel desired functions or to better understand and redesign biological processes. Synthetic biological digital circuits could lead to new therapeutic approaches, as well as new and efficient ways to produce complex molecules such as antibiotics, bioplastics or biofuels. Biological computation not only provides possible biomedical and biotechnological applications, but also affords a greater understanding of biological systems.

Earth Science Mining Web Services

NASA Technical Reports Server (NTRS)

Pham, Long; Lynnes, Christopher; Hegde, Mahabaleshwa; Graves, Sara; Ramachandran, Rahul; Maskey, Manil; Keiser, Ken

2008-01-01

To allow scientists further capabilities in the area of data mining and web services, the Goddard Earth Sciences Data and Information Services Center (GES DISC) and researchers at the University of Alabama in Huntsville (UAH) have developed a system to mine data at the source without the need of network transfers. The system has been constructed by linking together several pre-existing technologies: the Simple Scalable Script-based Science Processor for Measurements (S4PM), a processing engine at he GES DISC; the Algorithm Development and Mining (ADaM) system, a data mining toolkit from UAH that can be configured in a variety of ways to create customized mining processes; ActiveBPEL, a workflow execution engine based on BPEL (Business Process Execution Language); XBaya, a graphical workflow composer; and the EOS Clearinghouse (ECHO). XBaya is used to construct an analysis workflow at UAH using ADam components, which are also installed remotely at the GES DISC, wrapped as Web Services. The S4PM processing engine searches ECHO for data using space-time criteria, staging them to cache, allowing the ActiveBPEL engine to remotely orchestras the processing workflow within S4PM. As mining is completed, the output is placed in an FTP holding area for the end user. The goals are to give users control over the data they want to process, while mining data at the data source using the server's resources rather than transferring the full volume over the internet. These diverse technologies have been infused into a functioning, distributed system with only minor changes to the underlying technologies. The key to the infusion is the loosely coupled, Web-Services based architecture: All of the participating components are accessible (one way or another) through (Simple Object Access Protocol) SOAP-based Web Services.

The Brazilian Portuguese Lexicon: An Instrument for Psycholinguistic Research

PubMed Central

Estivalet, Gustavo L.; Meunier, Fanny

2015-01-01

In this article, we present the Brazilian Portuguese Lexicon, a new word-based corpus for psycholinguistic and computational linguistic research in Brazilian Portuguese. We describe the corpus development, the specific characteristics on the internet site and database for user access. We also perform distributional analyses of the corpus and comparisons to other current databases. Our main objective was to provide a large, reliable, and useful word-based corpus with a dynamic, easy-to-use, and intuitive interface with free internet access for word and word-criteria searches. We used the Núcleo Interinstitucional de Linguística Computacional’s corpus as the basic data source and developed the Brazilian Portuguese Lexicon by deriving and adding metalinguistic and psycholinguistic information about Brazilian Portuguese words. We obtained a final corpus with more than 30 million word tokens, 215 thousand word types and 25 categories of information about each word. This corpus was made available on the internet via a free-access site with two search engines: a simple search and a complex search. The simple engine basically searches for a list of words, while the complex engine accepts all types of criteria in the corpus categories. The output result presents all entries found in the corpus with the criteria specified in the input search and can be downloaded as a.csv file. We created a module in the results that delivers basic statistics about each search. The Brazilian Portuguese Lexicon also provides a pseudoword engine and specific tools for linguistic and statistical analysis. Therefore, the Brazilian Portuguese Lexicon is a convenient instrument for stimulus search, selection, control, and manipulation in psycholinguistic experiments, as also it is a powerful database for computational linguistics research and language modeling related to lexicon distribution, functioning, and behavior. PMID:26630138

The Brazilian Portuguese Lexicon: An Instrument for Psycholinguistic Research.

PubMed

Estivalet, Gustavo L; Meunier, Fanny

2015-01-01

In this article, we present the Brazilian Portuguese Lexicon, a new word-based corpus for psycholinguistic and computational linguistic research in Brazilian Portuguese. We describe the corpus development, the specific characteristics on the internet site and database for user access. We also perform distributional analyses of the corpus and comparisons to other current databases. Our main objective was to provide a large, reliable, and useful word-based corpus with a dynamic, easy-to-use, and intuitive interface with free internet access for word and word-criteria searches. We used the Núcleo Interinstitucional de Linguística Computacional's corpus as the basic data source and developed the Brazilian Portuguese Lexicon by deriving and adding metalinguistic and psycholinguistic information about Brazilian Portuguese words. We obtained a final corpus with more than 30 million word tokens, 215 thousand word types and 25 categories of information about each word. This corpus was made available on the internet via a free-access site with two search engines: a simple search and a complex search. The simple engine basically searches for a list of words, while the complex engine accepts all types of criteria in the corpus categories. The output result presents all entries found in the corpus with the criteria specified in the input search and can be downloaded as a.csv file. We created a module in the results that delivers basic statistics about each search. The Brazilian Portuguese Lexicon also provides a pseudoword engine and specific tools for linguistic and statistical analysis. Therefore, the Brazilian Portuguese Lexicon is a convenient instrument for stimulus search, selection, control, and manipulation in psycholinguistic experiments, as also it is a powerful database for computational linguistics research and language modeling related to lexicon distribution, functioning, and behavior.

The Future of Metabolic Engineering and Synthetic Biology: Towards a Systematic Practice

PubMed Central

Yadav, Vikramaditya G.; De Mey, Marjan; Lim, Chin Giaw; Ajikumar, Parayil Kumaran; Stephanopoulos, Gregory

2012-01-01

Industrial biotechnology promises to revolutionize conventional chemical manufacturing in the years ahead, largely owing to the excellent progress in our ability to re-engineer cellular metabolism. However, most successes of metabolic engineering have been confined to over-producing natively synthesized metabolites in E. coli and S. cerevisiae. A major reason for this development has been the descent of metabolic engineering, particularly secondary metabolic engineering, to a collection of demonstrations rather than a systematic practice with generalizable tools. Synthetic biology, a more recent development, faces similar criticisms. Herein, we attempt to lay down a framework around which bioreaction engineering can systematize itself just like chemical reaction engineering. Central to this undertaking is a new approach to engineering secondary metabolism known as ‘multivariate modular metabolic engineering’ (MMME), whose novelty lies in its assessment and elimination of regulatory and pathway bottlenecks by re-defining the metabolic network as a collection of distinct modules. After introducing the core principles of MMME, we shall then present a number of recent developments in secondary metabolic engineering that could potentially serve as its facilitators. It is hoped that the ever-declining costs of de novo gene synthesis; the improved use of bioinformatic tools to mine, sort and analyze biological data; and the increasing sensitivity and sophistication of investigational tools will make the maturation of microbial metabolic engineering an autocatalytic process. Encouraged by these advances, research groups across the world would take up the challenge of secondary metabolite production in simple hosts with renewed vigor, thereby adding to the range of products synthesized using metabolic engineering. PMID:22629571

Simultaneous high-speed gas property measurements at the exhaust gas recirculation cooler exit and at the turbocharger inlet of a multicylinder diesel engine using diode-laser-absorption spectroscopy.

PubMed

Jatana, Gurneesh S; Magee, Mark; Fain, David; Naik, Sameer V; Shaver, Gregory M; Lucht, Robert P

2015-02-10

A diode-laser-absorption-spectroscopy-based sensor system was used to perform high-speed (100 Hz to 5 kHz) measurements of gas properties (temperature, pressure, and H(2)O vapor concentration) at the turbocharger inlet and at the exhaust gas recirculation (EGR) cooler exit of a diesel engine. An earlier version of this system was previously used for high-speed measurements of gas temperature and H(2)O vapor concentration in the intake manifold of the diesel engine. A 1387.2 N m tunable distributed feedback diode laser was used to scan across multiple H(2)O absorption transitions, and the direct absorption signal was recorded using a high-speed data acquisition system. Compact optical connectors were designed to conduct simultaneous measurements in the intake manifold, the EGR cooler exit, and the turbocharger inlet of the engine. For measurements at the turbocharger inlet, these custom optical connectors survived gas temperatures as high as 800 K using a simple and passive arrangement in which the temperature-sensitive components were protected from high temperatures using ceramic insulators. This arrangement reduced system cost and complexity by eliminating the need for any active water or oil cooling. Diode-laser measurements performed during steady-state engine operation were within 5% of the thermocouple and pressure sensor measurements, and within 10% of the H(2)O concentration values derived from the CO(2) gas analyzer measurements. Measurements were also performed in the engine during transient events. In one such transient event, where a step change in fueling was introduced, the diode-laser sensor was able to capture the 30 ms change in the gas properties; the thermocouple, on the other hand, required 7.4 s to accurately reflect the change in gas conditions, while the gas analyzer required nearly 600 ms. To the best of our knowledge, this is the first implementation of such a simple and passive arrangement of high-temperature optical connectors as well as the first documented application of diode-laser absorption for high-speed gas dynamics measurements in the turbocharger inlet and EGR cooler exit of a diesel engine.

A Nomographic Methodology for Use in Performance Trade-Off Studies of Parabolic Dish Solar Power Modules

NASA Technical Reports Server (NTRS)

Selcuk, M. K.; Fujita, T.

1984-01-01

A simple graphical method was developed to undertake technical design trade-off studies for individual parabolic dish models comprising a two-axis tracking parabolic dish with a cavity receiver and power conversion assembly at the focal point. The results of these technical studies are then used in performing the techno-economic analyses required for determining appropriate subsystem sizing. Selected graphs that characterize the performance of subsystems within the module were arranged in the form of a nomogram that would enable an investigator to carry out several design trade-off studies. Key performance parameters encompassed in the nomogram include receiver losses, intercept factor, engine rating, and engine efficiency. Design and operation parameters such as concentrator size, receiver type (open or windowed aperture), receiver aperture size, operating temperature of the receiver and engine, engine partial load characteristics, concentrator slope error, and the type of reflector surface, are also included in the graphical solution. Cost considerations are not included.

McrEngine: A Scalable Checkpointing System Using Data-Aware Aggregation and Compression

DOE PAGES

Islam, Tanzima Zerin; Mohror, Kathryn; Bagchi, Saurabh; ...

2013-01-01

High performance computing (HPC) systems use checkpoint-restart to tolerate failures. Typically, applications store their states in checkpoints on a parallel file system (PFS). As applications scale up, checkpoint-restart incurs high overheads due to contention for PFS resources. The high overheads force large-scale applications to reduce checkpoint frequency, which means more compute time is lost in the event of failure. We alleviate this problem through a scalable checkpoint-restart system, mcrEngine. McrEngine aggregates checkpoints from multiple application processes with knowledge of the data semantics available through widely-used I/O libraries, e.g., HDF5 and netCDF, and compresses them. Our novel scheme improves compressibility ofmore » checkpoints up to 115% over simple concatenation and compression. Our evaluation with large-scale application checkpoints show that mcrEngine reduces checkpointing overhead by up to 87% and restart overhead by up to 62% over a baseline with no aggregation or compression.« less

Secured independent tools in peritoneoscopy.

PubMed

Tsin, Daniel A; Davila, Fausto; Dominguez, Guillermo; Manolas, Panagiotis

2010-01-01

Secured independent tools are being introduced to aid in peritoneoscopy. We present a simple technique for anchoring instruments, powered lights, and micro machines through the abdominal wall. We used a laparoscopic trainer, micro alligator clips with one or two 2-0 nylon tails and cables for engines and lights. The above instruments were introduced via a 12-mm or 15-mm port. Clips were placed for traction, retraction and exposure, lights for illumination, and motors for potential work. A laparoscopy port closure or suture passer was introduced percutaneously to grab and extract the tails or cables outside of the simulated abdominal cavity. The engines and lights were powered by a direct electric current (DC) plugged into exteriorized cables. We used 2 to 3 clips for each, and engines performed well. This basic simulation adds independent instruments, lights, and engines. We replaced cannulas with threads or cables in an attempt to limit the number of ports. This technique further opens the door for innovations in wired machines in laparoscopy, single-port laparoscopy, or natural orifice surgery.

Optimization of a yeast RNA interference system for controlling gene expression and enabling rapid metabolic engineering.

PubMed

Crook, Nathan C; Schmitz, Alexander C; Alper, Hal S

2014-05-16

Reduction of endogenous gene expression is a fundamental operation of metabolic engineering, yet current methods for gene knockdown (i.e., genome editing) remain laborious and slow, especially in yeast. In contrast, RNA interference allows facile and tunable gene knockdown via a simple plasmid transformation step, enabling metabolic engineers to rapidly prototype knockdown strategies in multiple strains before expending significant cost to undertake genome editing. Although RNAi is naturally present in a myriad of eukaryotes, it has only been recently implemented in Saccharomyces cerevisiae as a heterologous pathway and so has not yet been optimized as a metabolic engineering tool. In this study, we elucidate a set of design principles for the construction of hairpin RNA expression cassettes in yeast and implement RNA interference to quickly identify routes for improvement of itaconic acid production in this organism. The approach developed here enables rapid prototyping of knockdown strategies and thus accelerates and reduces the cost of the design-build-test cycle in yeast.

Integrating ecological and engineering concepts of resilience in microbial communities

DOE PAGES

Song, Hyun -Seob; Renslow, Ryan S.; Fredrickson, Jim K.; ...

2015-12-01

We note that many definitions of resilience have been proffered for natural and engineered ecosystems, but a conceptual consensus on resilience in microbial communities is still lacking. Here, we argue that the disconnect largely results from the wide variance in microbial community complexity, which range from simple synthetic consortia to complex natural communities, and divergence between the typical practical outcomes emphasized by ecologists and engineers. Viewing microbial communities as elasto-plastic systems, we argue that this gap between the engineering and ecological definitions of resilience stems from their respective emphases on elastic and plastic deformation, respectively. We propose that the twomore » concepts may be fundamentally united around the resilience of function rather than state in microbial communities and the regularity in the relationship between environmental variation and a community’s functional response. Furthermore, we posit that functional resilience is an intrinsic property of microbial communities, suggesting that state changes in response to environmental variation may be a key mechanism driving resilience in microbial communities.« less

Global and Arctic climate engineering: numerical model studies.

PubMed

Caldeira, Ken; Wood, Lowell

2008-11-13

We perform numerical simulations of the atmosphere, sea ice and upper ocean to examine possible effects of diminishing incoming solar radiation, insolation, on the climate system. We simulate both global and Arctic climate engineering in idealized scenarios in which insolation is diminished above the top of the atmosphere. We consider the Arctic scenarios because climate change is manifesting most strongly there. Our results indicate that, while such simple insolation modulation is unlikely to perfectly reverse the effects of greenhouse gas warming, over a broad range of measures considering both temperature and water, an engineered high CO2 climate can be made much more similar to the low CO2 climate than would be a high CO2 climate in the absence of such engineering. At high latitudes, there is less sunlight deflected per unit albedo change but climate system feedbacks operate more powerfully there. These two effects largely cancel each other, making the global mean temperature response per unit top-of-atmosphere albedo change relatively insensitive to latitude. Implementing insolation modulation appears to be feasible.

The Simulation of Magnetorheological Elastomers Adaptive Tuned Dynamic Vibration Absorber for Automobile Engine Vibration Control

NASA Astrophysics Data System (ADS)

Zhang, X. C.; Zhang, X. Z.; Li, W. H.; Liu, B.; Gong, X. L.; Zhang, P. Q.

The aim of this article is to investigate the use of a Dynamic Vibration Absorber to control vibration of engine by using simulation. Traditional means of vibration control have involved the use of passive and more recently, active methods. This study is different in that it involves an adaptive component in the design of vibration absorber using magnetorheological elastomers (MREs) as the adaptive spring. MREs are kind of novel smart material whose shear modulus can be controlled by applied magnetic field. In this paper, the vibration mode of a simple model of automobile engine is simulated by Finite Element Method (FEM) analysis. Based on the analysis, the MREs Adaptive Tuned Dynamic Vibration Absorber (ATDVA) is presented to reduce the vibration of the engine. Simulation result indicate that the control frequency of ATDVA can be changed by modifing the shear modulus of MREs and the vibraion reduction efficiency of ATDVA are also evaluated by FEM analysis.

SIMPL: A Simplified Model-Based Program for the Analysis and Visualization of Groundwater Rebound in Abandoned Mines to Prevent Contamination of Water and Soils by Acid Mine Drainage

PubMed Central

Kim, Sung-Min

2018-01-01

Cessation of dewatering following underground mine closure typically results in groundwater rebound, because mine voids and surrounding strata undergo flooding up to the levels of the decant points, such as shafts and drifts. SIMPL (Simplified groundwater program In Mine workings using the Pipe equation and Lumped parameter model), a simplified lumped parameter model-based program for predicting groundwater levels in abandoned mines, is presented herein. The program comprises a simulation engine module, 3D visualization module, and graphical user interface, which aids data processing, analysis, and visualization of results. The 3D viewer facilitates effective visualization of the predicted groundwater level rebound phenomenon together with a topographic map, mine drift, goaf, and geological properties from borehole data. SIMPL is applied to data from the Dongwon coal mine and Dalsung copper mine in Korea, with strong similarities in simulated and observed results. By considering mine workings and interpond connections, SIMPL can thus be used to effectively analyze and visualize groundwater rebound. In addition, the predictions by SIMPL can be utilized to prevent the surrounding environment (water and soil) from being polluted by acid mine drainage. PMID:29747480

Engineering entropy-driven reactions and networks catalyzed by DNA.

PubMed

Zhang, David Yu; Turberfield, Andrew J; Yurke, Bernard; Winfree, Erik

2007-11-16

Artificial biochemical circuits are likely to play as large a role in biological engineering as electrical circuits have played in the engineering of electromechanical devices. Toward that end, nucleic acids provide a designable substrate for the regulation of biochemical reactions. However, it has been difficult to incorporate signal amplification components. We introduce a design strategy that allows a specified input oligonucleotide to catalyze the release of a specified output oligonucleotide, which in turn can serve as a catalyst for other reactions. This reaction, which is driven forward by the configurational entropy of the released molecule, provides an amplifying circuit element that is simple, fast, modular, composable, and robust. We have constructed and characterized several circuits that amplify nucleic acid signals, including a feedforward cascade with quadratic kinetics and a positive feedback circuit with exponential growth kinetics.

Using virtual environment for autonomous vehicle algorithm validation

NASA Astrophysics Data System (ADS)

Levinskis, Aleksandrs

2018-04-01

This paper describes possible use of modern game engine for validating and proving the concept of algorithm design. As the result simple visual odometry algorithm will be provided to show the concept and go over all workflow stages. Some of stages will involve using of Kalman filter in such a way that it will estimate optical flow velocity as well as position of moving camera located at vehicle body. In particular Unreal Engine 4 game engine will be used for generating optical flow patterns and ground truth path. For optical flow determination Horn and Schunck method will be applied. As the result, it will be shown that such method can estimate position of the camera attached to vehicle with certain displacement error respect to ground truth depending on optical flow pattern. For displacement rate RMS error is calculating between estimated and actual position.

Automotive dual-mode hydrogen generation system

NASA Astrophysics Data System (ADS)

Kelly, D. A.

The automotive dual mode hydrogen generation system is advocated as a supplementary hydrogen fuel means along with the current metallic hydride hydrogen storage method for vehicles. This system consists of utilizing conventional electrolysis cells with the low voltage dc electrical power supplied by two electrical generating sources within the vehicle. Since the automobile engine exhaust manifold(s) are presently an untapped useful source of thermal energy, they can be employed as the heat source for a simple heat engine/generator arrangement. The second, and minor electrical generating means consists of multiple, miniature air disk generators which are mounted directly under the vehicle's hood and at other convenient locations within the engine compartment. The air disk generators are revolved at a speed which is proportionate to the vehicles forward speed and do not impose a drag on the vehicles motion.

Reuse of Aluminum Dross as an Engineered Product

NASA Astrophysics Data System (ADS)

Dai, Chen; Apelian, Diran

To prevent the leaching of landfilled aluminum dross waste and save the energy consumed by recovering metallic aluminum from dross, aluminum dross is reused as an engineering product directly rather than "refurbished" ineffectively. The concept is to reduce waste and to reuse. Two kinds of aluminum dross from industrial streams were selected and characterized. We have shown that dross can be applied directly, or accompanied with a simple conditioning process, to manufacture refractory components. Dross particles below 50 mesh are most effective. Mechanical property evaluations revealed the possibility for dross waste to be utilized as filler in concrete, resulting in up to 40% higher flexural strength and 10% higher compressive strength compared to pure cement, as well as cement with sand additions. The potential usage of aluminum dross as a raw material for such engineering applications is presented and discussed.

Electricity from the Silk Cocoon Membrane

PubMed Central

Tulachan, Brindan; Meena, Sunil Kumar; Rai, Ratan Kumar; Mallick, Chandrakant; Kusurkar, Tejas Sanjeev; Teotia, Arun Kumar; Sethy, Niroj Kumar; Bhargava, Kalpana; Bhattacharya, Shantanu; Kumar, Ashok; Sharma, Raj Kishore; Sinha, Neeraj; Singh, Sushil Kumar; Das, Mainak

2014-01-01

Silk cocoon membrane (SCM) is an insect engineered structure. We studied the electrical properties of mulberry (Bombyx mori) and non-mulberry (Tussar, Antheraea mylitta) SCM. When dry, SCM behaves like an insulator. On absorbing moisture, it generates electrical current, which is modulated by temperature. The current flowing across the SCM is possibly ionic and protonic in nature. We exploited the electrical properties of SCM to develop simple energy harvesting devices, which could operate low power electronic systems. Based on our findings, we propose that the temperature and humidity dependent electrical properties of the SCM could find applications in battery technology, bio-sensor, humidity sensor, steam engines and waste heat management. PMID:24961354

Electricity from the silk cocoon membrane.

PubMed

Tulachan, Brindan; Meena, Sunil Kumar; Rai, Ratan Kumar; Mallick, Chandrakant; Kusurkar, Tejas Sanjeev; Teotia, Arun Kumar; Sethy, Niroj Kumar; Bhargava, Kalpana; Bhattacharya, Shantanu; Kumar, Ashok; Sharma, Raj Kishore; Sinha, Neeraj; Singh, Sushil Kumar; Das, Mainak

2014-06-25

Silk cocoon membrane (SCM) is an insect engineered structure. We studied the electrical properties of mulberry (Bombyx mori) and non-mulberry (Tussar, Antheraea mylitta) SCM. When dry, SCM behaves like an insulator. On absorbing moisture, it generates electrical current, which is modulated by temperature. The current flowing across the SCM is possibly ionic and protonic in nature. We exploited the electrical properties of SCM to develop simple energy harvesting devices, which could operate low power electronic systems. Based on our findings, we propose that the temperature and humidity dependent electrical properties of the SCM could find applications in battery technology, bio-sensor, humidity sensor, steam engines and waste heat management.

Helicopter rotor and engine sizing for preliminary performance estimation

NASA Technical Reports Server (NTRS)

Talbot, P. D.; Bowles, J. V.; Lee, H. C.

1986-01-01

Methods are presented for estimating some of the more fundamental design variables of single-rotor helicopters (tip speed, blade area, disk loading, and installed power) based on design requirements (speed, weight, fuselage drag, and design hover ceiling). The well-known constraints of advancing-blade compressibility and retreating-blade stall are incorporated into the estimation process, based on an empirical interpretation of rotor performance data from large-scale wind-tunnel tests. Engine performance data are presented and correlated with a simple model usable for preliminary design. When approximate results are required quickly, these methods may be more convenient to use and provide more insight than large digital computer programs.

Natural and engineered biosynthesis of nucleoside antibiotics in Actinomycetes.

PubMed

Chen, Wenqing; Qi, Jianzhao; Wu, Pan; Wan, Dan; Liu, Jin; Feng, Xuan; Deng, Zixin

2016-03-01

Nucleoside antibiotics constitute an important family of microbial natural products bearing diverse bioactivities and unusual structural features. Their biosynthetic logics are unique with involvement of complex multi-enzymatic reactions leading to the intricate molecules from simple building blocks. Understanding how nature builds this family of antibiotics in post-genomic era sets the stage for rational enhancement of their production, and also paves the way for targeted persuasion of the cell factories to make artificial designer nucleoside drugs and leads via synthetic biology approaches. In this review, we discuss the recent progress and perspectives on the natural and engineered biosynthesis of nucleoside antibiotics.

Evolution of corundum-structured III-oxide semiconductors: Growth, properties, and devices

NASA Astrophysics Data System (ADS)

Fujita, Shizuo; Oda, Masaya; Kaneko, Kentaro; Hitora, Toshimi

2016-12-01

The recent progress and development of corundum-structured III-oxide semiconductors are reviewed. They allow bandgap engineering from 3.7 to ∼9 eV and function engineering, leading to highly durable electronic devices and deep ultraviolet optical devices as well as multifunctional devices. Mist chemical vapor deposition can be a simple and safe growth technology and is advantageous for reducing energy and cost for the growth. This is favorable for the wide commercial use of devices at low cost. The III-oxide semiconductors are promising candidates for new devices contributing to sustainable social, economic, and technological development for the future.