Engineering two-wire optical antennas for near field enhancement

NASA Astrophysics Data System (ADS)

Yang, Zhong-Jian; Zhao, Qian; Xiao, Si; He, Jun

2017-07-01

We study the optimization of near field enhancement in the two-wire optical antenna system. By varying the nanowire sizes we obtain the optimized side-length (width and height) for the maximum field enhancement with a given gap size. The optimized side-length applies to a broadband range (λ = 650-1000 nm). The ratio of extinction cross section to field concentration size is found to be closely related to the field enhancement behavior. We also investigate two experimentally feasible cases which are antennas on glass substrate and mirror, and find that the optimized side-length also applies to these systems. It is also found that the optimized side-length shows a tendency of increasing with the gap size. Our results could find applications in field-enhanced spectroscopies.

Variable aperture-based ptychographical iterative engine method

NASA Astrophysics Data System (ADS)

Sun, Aihui; Kong, Yan; Meng, Xin; He, Xiaoliang; Du, Ruijun; Jiang, Zhilong; Liu, Fei; Xue, Liang; Wang, Shouyu; Liu, Cheng

2018-02-01

A variable aperture-based ptychographical iterative engine (vaPIE) is demonstrated both numerically and experimentally to reconstruct the sample phase and amplitude rapidly. By adjusting the size of a tiny aperture under the illumination of a parallel light beam to change the illumination on the sample step by step and recording the corresponding diffraction patterns sequentially, both the sample phase and amplitude can be faithfully reconstructed with a modified ptychographical iterative engine (PIE) algorithm. Since many fewer diffraction patterns are required than in common PIE and the shape, the size, and the position of the aperture need not to be known exactly, this proposed vaPIE method remarkably reduces the data acquisition time and makes PIE less dependent on the mechanical accuracy of the translation stage; therefore, the proposed technique can be potentially applied for various scientific researches.

Analytical determination of critical crack size in solar cells

NASA Technical Reports Server (NTRS)

Chen, C. P.

1988-01-01

Although solar cells usually have chips and cracks, no material specifications concerning the allowable crack size on solar cells are available for quality assurance and engineering design usage. Any material specifications that the cell manufacturers use were developed for cosmetic reasons that have no technical basis. Therefore, the Applied Solar Energy Corporation (ASEC) has sponsored a continuing program for the fracture mechanics evaluation of GaAs. Fracture mechanics concepts were utilized to develop an analytical model that can predict the critical crack size of solar cells. This model indicates that the edge cracks of a solar cell are more critical than its surface cracks. In addition, the model suggests that the material specifications on the allowable crack size used for Si solar cells should not be applied to GaAs solar cells. The analytical model was applied to Si and GaAs solar cells, but it would also be applicable to the semiconductor wafers of other materials, such as a GaAs thin film on a Ge substrate, using appropriate input data.

Design Study of Propulsion and Drive Systems for the Large Civil TiltRotor (LCTR2) Rotorcraft

NASA Technical Reports Server (NTRS)

Robuck, Mark; Wilkerson, Joseph; Zhang, Yiyi; Snyder, Christopher A.; Vonderwell, Daniel

2013-01-01

Boeing, Rolls Royce, and NASA have worked together to complete a parametric sizing study for NASA's Large Civil Tilt Rotor (LCTR2) concept 2nd iteration. Vehicle gross weight and fuel usage were evaluated as propulsion and drive system characteristics were varied to maximize the benefit of reduced rotor tip speed during cruise conditions. The study examined different combinations of engine and gearbox variability to achieve rotor cruise tip speed reductions down to 54% of the hover tip speed. Previous NASA studies identified that a 54% rotor speed reduction in cruise minimizes vehicle gross weight and fuel burn. The LCTR2 was the study baseline for initial sizing. This study included rotor tip speed ratios (cruise to hover) of 100%, 77% and 54% at different combinations of engine RPM and gearbox speed reductions, which were analyzed to achieve the lightest overall vehicle gross weight (GW) at the chosen rotor tip speed ratio. Different engine and gearbox technology levels are applied ranging from commercial off-the-shelf (COTS) engines and gearbox technology to entry-in-service (EIS) dates of 2025 and 2035 to assess the benefits of advanced technology on vehicle gross weight and fuel burn. Interim results were previously reported1. This technical paper extends that work and summarizes the final study results including additional engine and drive system study accomplishments. New vehicle sizing data is presented for engine performance at a single operating speed with a multispeed drive system. Modeling details for LCTR2 vehicle sizing and subject engine and drive sub-systems are presented as well. This study was conducted in support of NASA's Fundamental Aeronautics Program, Subsonic Rotary Wing Project.

23 CFR 658.7 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Applicability. 658.7 Section 658.7 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND... access thereto. However, nothing in this regulation shall be construed to prevent any State from applying...

23 CFR 658.7 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Applicability. 658.7 Section 658.7 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND... access thereto. However, nothing in this regulation shall be construed to prevent any State from applying...

23 CFR 658.7 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Applicability. 658.7 Section 658.7 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND... access thereto. However, nothing in this regulation shall be construed to prevent any State from applying...

23 CFR 658.7 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Applicability. 658.7 Section 658.7 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND... access thereto. However, nothing in this regulation shall be construed to prevent any State from applying...

23 CFR 658.7 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Applicability. 658.7 Section 658.7 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND... access thereto. However, nothing in this regulation shall be construed to prevent any State from applying...

Advancements Toward Oil-Free Rotorcraft Propulsion

NASA Technical Reports Server (NTRS)

Howard, Samuel A.; Bruckner, Robert J.; Radil, Kevin C.

2010-01-01

NASA and the Army have been working for over a decade to advance the state-of-the-art (SOA) in Oil-Free Turbomachinery with an eye toward reduced emissions and maintenance, and increased performance and efficiency among other benefits. Oil-Free Turbomachinery is enabled by oil-free gas foil bearing technology and relatively new high-temperature tribological coatings. Rotorcraft propulsion is a likely candidate to apply oil-free bearing technology because the engine size class matches current SOA for foil bearings and because foil bearings offer the opportunity for higher speeds and temperatures and lower weight, all critical issues for rotorcraft engines. This paper describes an effort to demonstrate gas foil journal bearing use in the hot section of a full-scale helicopter engine core. A production engine hot-core location is selected as the candidate foil bearing application. Rotordynamic feasibility, bearing sizing, and load capability are assessed. The results of the program will help guide future analysis and design in this area by documenting the steps required and the process utilized for successful application of oil-free technology to a full-scale engine.

Development of an Indirect Stereolithography Technology for Scaffold Fabrication with a Wide Range of Biomaterial Selectivity

PubMed Central

Kang, Hyun-Wook

2012-01-01

Tissue engineering, which is the study of generating biological substitutes to restore or replace tissues or organs, has the potential to meet current needs for organ transplantation and medical interventions. Various approaches have been attempted to apply three-dimensional (3D) solid freeform fabrication technologies to tissue engineering for scaffold fabrication. Among these, the stereolithography (SL) technology not only has the highest resolution, but also offers quick fabrication. However, a lack of suitable biomaterials is a barrier to applying the SL technology to tissue engineering. In this study, an indirect SL method that combines the SL technology and a sacrificial molding process was developed to address this challenge. A sacrificial mold with an inverse porous shape was fabricated from an alkali-soluble photopolymer by the SL technology. A sacrificial molding process was then developed for scaffold construction using a variety of biomaterials. The results indicated a wide range of biomaterial selectivity and a high resolution. Achievable minimum pore and strut sizes were as large as 50 and 65 μm, respectively. This technology can also be used to fabricate three-dimensional organ shapes, and combined with traditional fabrication methods to construct a new type of scaffold with a dual-pore size. Cytotoxicity tests, as well as nuclear magnetic resonance and gel permeation chromatography analyses, showed that this technology has great potential for tissue engineering applications. PMID:22443315

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.

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

NASA Technical Reports Server (NTRS)

MacConochie, Ian O.; Stnaley, Douglas O.

1991-01-01

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

The Attributes of a Variable-Diameter Rotor System Applied to Civil Tiltrotor Aircraft

NASA Technical Reports Server (NTRS)

Brender, Scott; Mark, Hans; Aguilera, Frank

1996-01-01

The attributes of a variable diameter rotor concept applied to civil tiltrotor aircraft are investigated using the V/STOL aircraft sizing and performance computer program (VASCOMP). To begin, civil tiltrotor viability issues that motivate advanced rotor designs are discussed. Current work on the variable diameter rotor and a theoretical basis for the advantages of the rotor system are presented. The size and performance of variable diameter and conventional tiltrotor designs for the same baseline mission are then calculated using a modified NASA Ames version of VASCOMP. The aircraft are compared based on gross weight, fuel required, engine size, and autorotative performance for various hover disk loading values. Conclusions about the viability of the resulting designs are presented and a program for further variable diameter rotor research is recommended.

Human Urine Derived Stem Cells in Combination with β-TCP Can Be Applied for Bone Regeneration.

PubMed

Guan, Junjie; Zhang, Jieyuan; Li, Haiyan; Zhu, Zhenzhong; Guo, Shangchun; Niu, Xin; Wang, Yang; Zhang, Changqing

2015-01-01

Bone tissue engineering requires highly proliferative stem cells that are easy to isolate. Human urine stem cells (USCs) are abundant and can be easily harvested without using an invasive procedure. In addition, in our previous studies, USCs have been proved to be able to differentiate into osteoblasts, chondrocytes, and adipocytes. Therefore, USCs may have great potential and advantages to be applied as a cell source for tissue engineering. However, there are no published studies that describe the interactions between USCs and biomaterials and applications of USCs for bone tissue engineering. Therefore, the objective of the present study was to evaluate the interactions between USCs with a typical bone tissue engineering scaffold, beta-Tricalcium Phosphate (β-TCP), and to determine whether the USCs seeded onto β-TCP scaffold can promote bone regeneration in a segmental femoral defect of rats. Primary USCs were isolated from urine and seeded on β-TCP scaffolds. Results showed that USCs remained viable and proliferated within β-TCP. The osteogenic differentiation of USCs within the scaffolds was demonstrated by increased alkaline phosphatase activity and calcium content. Furthermore, β-TCP with adherent USCs (USCs/β-TCP) were implanted in a 6-mm critical size femoral defect of rats for 12 weeks. Bone regeneration was determined using X-ray, micro-CT, and histologic analyses. Results further demonstrated that USCs in the scaffolds could enhance new bone formation, which spanned bone defects in 5 out of 11 rats while β-TCP scaffold alone induced modest bone formation. The current study indicated that the USCs can be used as a cell source for bone tissue engineering as they are compatible with bone tissue engineering scaffolds and can stimulate the regeneration of bone in a critical size bone defect.

Scaling of Performance in Liquid Propellant Rocket Engine Combustors

NASA Technical Reports Server (NTRS)

Hulka, James

2008-01-01

The objectives are: a) Re-introduce to you the concept of scaling; b) Describe the scaling research conducted in the 1950s and early 1960s, and present some of their conclusions; c) Narrow the focus to scaling for performance of combustion devices for liquid propellant rocket engines; and d) Present some results of subscale to full-scale performance from historical programs. Scaling is "The ability to develop new combustion devices with predictable performance on the basis of test experience with old devices." Scaling can be used to develop combustion devices of any thrust size from any thrust size. Scaling is applied mostly to increase thrust. Objective is to use scaling as a development tool. - Move injector design from an "art" to a "science"

Neural Network-Based Sensor Validation for Turboshaft Engines

NASA Technical Reports Server (NTRS)

Moller, James C.; Litt, Jonathan S.; Guo, Ten-Huei

1998-01-01

Sensor failure detection, isolation, and accommodation using a neural network approach is described. An auto-associative neural network is configured to perform dimensionality reduction on the sensor measurement vector and provide estimated sensor values. The sensor validation scheme is applied in a simulation of the T700 turboshaft engine in closed loop operation. Performance is evaluated based on the ability to detect faults correctly and maintain stable and responsive engine operation. The set of sensor outputs used for engine control forms the network input vector. Analytical redundancy is verified by training networks of successively smaller bottleneck layer sizes. Training data generation and strategy are discussed. The engine maintained stable behavior in the presence of sensor hard failures. With proper selection of fault determination thresholds, stability was maintained in the presence of sensor soft failures.

Nanoparticle size detection limits by single particle ICP-MS for 40 elements.

PubMed

Lee, Sungyun; Bi, Xiangyu; Reed, Robert B; Ranville, James F; Herckes, Pierre; Westerhoff, Paul

2014-09-02

The quantification and characterization of natural, engineered, and incidental nano- to micro-size particles are beneficial to assessing a nanomaterial's performance in manufacturing, their fate and transport in the environment, and their potential risk to human health. Single particle inductively coupled plasma mass spectrometry (spICP-MS) can sensitively quantify the amount and size distribution of metallic nanoparticles suspended in aqueous matrices. To accurately obtain the nanoparticle size distribution, it is critical to have knowledge of the size detection limit (denoted as Dmin) using spICP-MS for a wide range of elements (other than a few available assessed ones) that have been or will be synthesized into engineered nanoparticles. Herein is described a method to estimate the size detection limit using spICP-MS and then apply it to nanoparticles composed of 40 different elements. The calculated Dmin values correspond well for a few of the elements with their detectable sizes that are available in the literature. Assuming each nanoparticle sample is composed of one element, Dmin values vary substantially among the 40 elements: Ta, U, Ir, Rh, Th, Ce, and Hf showed the lowest Dmin values, ≤10 nm; Bi, W, In, Pb, Pt, Ag, Au, Tl, Pd, Y, Ru, Cd, and Sb had Dmin in the range of 11-20 nm; Dmin values of Co, Sr, Sn, Zr, Ba, Te, Mo, Ni, V, Cu, Cr, Mg, Zn, Fe, Al, Li, and Ti were located at 21-80 nm; and Se, Ca, and Si showed high Dmin values, greater than 200 nm. A range of parameters that influence the Dmin, such as instrument sensitivity, nanoparticle density, and background noise, is demonstrated. It is observed that, when the background noise is low, the instrument sensitivity and nanoparticle density dominate the Dmin significantly. Approaches for reducing the Dmin, e.g., collision cell technology (CCT) and analyte isotope selection, are also discussed. To validate the Dmin estimation approach, size distributions for three engineered nanoparticle samples were obtained using spICP-MS. The use of this methodology confirms that the observed minimum detectable sizes are consistent with the calculated Dmin values. Overall, this work identifies the elements and nanoparticles to which current spICP-MS approaches can be applied, in order to enable quantification of very small nanoparticles at low concentrations in aqueous media.

Aluminum/hydrocarbon gel propellants: An experimental and theoretical investigation of secondary atomization and predicted rocket engine performance

NASA Astrophysics Data System (ADS)

Mueller, Donn Christopher

1997-12-01

Experimental and theoretical investigations of aluminum/hydrocarbon gel propellant secondary atomization and its potential effects on rocket engine performance were conducted. In the experimental efforts, a dilute, polydisperse, gel droplet spray was injected into the postflame region of a burner and droplet size distributions was measured as a function of position above the burner using a laser-based sizing/velocimetry technique. The sizing/velocimetry technique was developed to measure droplets in the 10-125 mum size range and avoids size-biased detection through the use of a uniformly illuminated probe volume. The technique was used to determine particle size distributions and velocities at various axial locations above the burner for JP-10, and 50 and 60 wt% aluminum gels. Droplet shell formation models were applied to aluminum/hydrocarbon gels to examine particle size and mass loading effects on the minimum droplet diameter that will permit secondary atomization. This diameter was predicted to be 38.1 and 34.7 mum for the 50 and 60 wt% gels, which is somewhat greater than the experimentally measured 30 and 25 mum diameters. In the theoretical efforts, three models were developed and an existing rocket code was exercised to gain insights into secondary atomization. The first model was designed to predict gel droplet properties and shell stresses after rigid shell formation, while the second, a one-dimensional gel spray combustion model was created to quantify the secondary atomization process. Experimental and numerical comparisons verify that secondary atomization occurs in 10-125 mum diameter particles although an exact model could not be derived. The third model, a one-dimensional gel-fueled rocket combustion chamber, was developed to evaluate secondary atomization effects on various engine performance parameters. Results show that only modest secondary atomization may be required to reduce propellant burnout distance and radiation losses. A solid propellant engine code was employed to estimate nozzle two-phase flow losses and engine performance for upper-stage and booster missions (3-6% and 2-3%, respectively). Given these losses and other difficulties, metallized gel propellants may be impractical in high-expansion ratio engines. Although uncertainties remain, it appears that performance gains will be minimal in gross-weight limited missions, but that significant gains may arise in volume-limited missions.

Compact LED based LCOS optical engine for mobile projection

NASA Astrophysics Data System (ADS)

Zhang, Wenzi; Li, Xiaoyan; Liu, Qinxiao; Yu, Feihong

2009-11-01

With the development of high power LED (light emitting diode) technology and color filter LCOS (liquid crystal on silicon) technology, the research on LED based micro optical engine for mobile projection has been a hot topic recently. In this paper one compact LED powered LCOS optical engine design is presented, which is intended to be embedded in cell phone, digital camera, and so on. Compared to DLP (digital light processor) and traditional color sequential LCOS technology, the color filter based LCOS panel is chosen for the compact optical engine, this is because only white LED is needed. To further decrease the size of the optical engine, only one specifically designed plastic free form lens is applied in the illumination part of the optical engine. This free form lens is designed so that it plays the roles of both condenser and integrator, by which the output light of LED is condensed and redistributed, and light illumination of high efficiency, high uniformity and small incident angle on LCOS is acquired. Besides PBS (polarization beam splitter), LCOS, and projection lens, the compact optical engine contains only this piece of free form plastic lens, which can be produced by plastic injection molding. Finally a white LED powered LCOS optical engine with a compact size of less than 6.6 cc can be acquired. With the ray tracing simulation result, the light efficiency analysis shows that the output flux is over 8.5 ANSI lumens and the ANSI uniformity of over 80%.

Concepts for Distributed Engine Control

NASA Technical Reports Server (NTRS)

Culley, Dennis E.; Thomas, Randy; Saus, Joseph

2007-01-01

Gas turbine engines for aero-propulsion systems are found to be highly optimized machines after over 70 years of development. Still, additional performance improvements are sought while reduction in the overall cost is increasingly a driving factor. Control systems play a vitally important part in these metrics but are severely constrained by the operating environment and the consequences of system failure. The considerable challenges facing future engine control system design have been investigated. A preliminary analysis has been conducted of the potential benefits of distributed control architecture when applied to aero-engines. In particular, reductions in size, weight, and cost of the control system are possible. NASA is conducting research to further explore these benefits, with emphasis on the particular benefits enabled by high temperature electronics and an open-systems approach to standardized communications interfaces.

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

Salama, A.; Mikhail, M.

Comprehensive software packages have been developed at the Western Research Centre as tools to help coal preparation engineers analyze, evaluate, and control coal cleaning processes. The COal Preparation Software package (COPS) performs three functions: (1) data handling and manipulation, (2) data analysis, including the generation of washability data, performance evaluation and prediction, density and size modeling, evaluation of density and size partition characteristics and attrition curves, and (3) generation of graphics output. The Separation ChARacteristics Estimation software packages (SCARE) are developed to balance raw density or size separation data. The cases of density and size separation data are considered. Themore » generated balanced data can take the balanced or normalized forms. The scaled form is desirable for direct determination of the partition functions (curves). The raw and generated separation data are displayed in tabular and/or graphical forms. The computer softwares described in this paper are valuable tools for coal preparation plant engineers and operators for evaluating process performance, adjusting plant parameters, and balancing raw density or size separation data. These packages have been applied very successfully in many projects carried out by WRC for the Canadian coal preparation industry. The software packages are designed to run on a personal computer (PC).« less

Modeling of a Turbofan Engine with Ice Crystal Ingestion in the NASA Propulsion System Laboratory

NASA Technical Reports Server (NTRS)

Veres, Joseph P.; Jorgenson, Philip C. E.; Jones, Scott M.; Nili, Samaun

2017-01-01

The main focus of this study is to apply a computational tool for the flow analysis of the turbine engine that has been tested with ice crystal ingestion in the Propulsion Systems Laboratory (PSL) at NASA Glenn Research Center. The PSL has been used to test a highly instrumented Honeywell ALF502R-5A (LF11) turbofan engine at simulated altitude operating conditions. Test data analysis with an engine cycle code and a compressor flow code was conducted to determine the values of key icing parameters, that can indicate the risk of ice accretion, which can lead to engine rollback (un-commanded loss of engine thrust). The full engine aerothermodynamic performance was modeled with the Honeywell Customer Deck specifically created for the ALF502R-5A engine. The mean-line compressor flow analysis code, which includes a code that models the state of the ice crystal, was used to model the air flow through the fan-core and low pressure compressor. The results of the compressor flow analyses included calculations of the ice-water flow rate to air flow rate ratio (IWAR), the local static wet bulb temperature, and the particle melt ratio throughout the flow field. It was found that the assumed particle size had a large effect on the particle melt ratio, and on the local wet bulb temperature. In this study the particle size was varied parametrically to produce a non-zero calculated melt ratio in the exit guide vane (EGV) region of the low pressure compressor (LPC) for the data points that experienced a growth of blockage there, and a subsequent engine called rollback (CRB). At data points where the engine experienced a CRB having the lowest wet bulb temperature of 492 degrees Rankine at the EGV trailing edge, the smallest particle size that produced a non-zero melt ratio (between 3 percent - 4 percent) was on the order of 1 micron. This value of melt ratio was utilized as the target for all other subsequent data points analyzed, while the particle size was varied from 1 micron - 9.5 microns to achieve the target melt ratio. For data points that did not experience a CRB which had static wet bulb temperatures in the EGV region below 492 degrees Rankine, a non-zero melt ratio could not be achieved even with a 1 micron ice particle size. The highest value of static wet bulb temperature for data points that experienced engine CRB was 498 degrees Rankine with a particle size of 9.5 microns. Based on this study of the LF11 engine test data, the range of static wet bulb temperature at the EGV exit for engine CRB was in the narrow range of 492 degrees Rankine - 498 degrees Rankine , while the minimum value of IWAR was 0.002. The rate of blockage growth due to ice accretion and boundary layer growth was estimated by scaling from a known blockage growth rate that was determined in a previous study. These results obtained from the LF11 engine analysis formed the basis of a unique “icing wedge.”

Development of an HL7 interface engine, based on tree structure and streaming algorithm, for large-size messages which include image data.

PubMed

Um, Ki Sung; Kwak, Yun Sik; Cho, Hune; Kim, Il Kon

2005-11-01

A basic assumption of Health Level Seven (HL7) protocol is 'No limitation of message length'. However, most existing commercial HL7 interface engines do limit message length because they use the string array method, which is run in the main memory for the HL7 message parsing process. Specifically, messages with image and multi-media data create a long string array and thus cause the computer system to raise critical and fatal problem. Consequently, HL7 messages cannot handle the image and multi-media data necessary in modern medical records. This study aims to solve this problem with the 'streaming algorithm' method. This new method for HL7 message parsing applies the character-stream object which process character by character between the main memory and hard disk device with the consequence that the processing load on main memory could be alleviated. The main functions of this new engine are generating, parsing, validating, browsing, sending, and receiving HL7 messages. Also, the engine can parse and generate XML-formatted HL7 messages. This new HL7 engine successfully exchanged HL7 messages with 10 megabyte size images and discharge summary information between two university hospitals.

Design concepts for low-cost composite turbofan engine frame

NASA Technical Reports Server (NTRS)

Mitchell, S. C.; Stoffer, L. J.

1980-01-01

Design concepts for low cost, lightweight composite engine frames were applied to the design requirements for the frame of a commercial, high bypass engine. Four alternative composite frame design concepts identified which consisted of generic type components and subcomponents that could be adapted to use in different locations in the engine and the different engine sizes. A variety of materials and manufacturing methods were projected with a goal for the lowest number of parts at the lowest possible cost. After a preliminary evaluation of all four frame concepts, two designs were selected for an extended design and evaluation which narrowed the final selection down to one frame that was significantly lower in cost and slighty lighter than the other frame. An implementation plan for this lowest cost frame is projected for future development and includes prospects for reducing its weight with proposed unproven, innovative fabrication techniques.

Energy use and taxation policy in the New Zealand car fleet

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

Not Available

1984-02-01

The report describes the composition of the New Zealand car fleet and the relationship between design factors, fleet composition, vehicle useage and fuel consumption. The indirect energy content of the vehicle and roadway are discussed. Existing and potential Government policy instruments for promoting fuel economy in the car fleet are discussed and evaluated. The report conclusions favor flat rate sales tax on vehicles regardless of engine size together with an appropriate level of petrol tax in preference to taxation that varies with vehicle size or engine capacity. A review of hire purchase regulations is proposed. Prior to publication of thismore » report the Industries Development Commission Plan for the motor vehicle industry was released which proposes changes to the tariff, taxation and credit purchase regime applying to motor vehicles. These changes are summarized.« less

Differences in Characteristics of Aviation Accidents During 1993-2012 Based on Aircraft Type

NASA Technical Reports Server (NTRS)

Evans, Joni K.

2015-01-01

Civilian aircraft are available in a variety of sizes, engine types, construction materials and instrumentation complexity. For the analysis reported here, eleven aircraft categories were developed based mostly on aircraft size and engine type, and these categories were applied to twenty consecutive years of civil aviation accidents. Differences in various factors were examined among these aircraft types, including accident severity, pilot characteristics and accident occurrence categories. In general, regional jets and very light sport aircraft had the lowest rates of adverse outcomes (injuries, fatal accidents, aircraft destruction, major accidents), while aircraft with twin (piston) engines or with a single (piston) engine and retractable landing gear carried the highest incidence of adverse outcomes. The accident categories of abnormal runway contact, runway excursions and non-powerplant system/component failures occur frequently within all but two or three aircraft types. In contrast, ground collisions, loss of control - on ground/water and powerplant system/component failure occur frequently within only one or two aircraft types. Although accidents in larger aircraft tend to have less severe outcomes, adverse outcome rates also differ among accident categories. It may be that the type of accident has as much or more influence on the outcome as the type of aircraft.

Nano and microparticle engineering of water insoluble drugs using a novel spray-drying process.

PubMed

Schafroth, Nina; Arpagaus, Cordin; Jadhav, Umesh Y; Makne, Sushil; Douroumis, Dennis

2012-02-01

In the current study nano and microparticle engineering of water insoluble drugs was conducted using a novel piezoelectric spray-drying approach. Cyclosporin A (CyA) and dexamethasone (DEX) were encapsulated in biodegradable poly(D,L-lactide-co-glycolide) (PLGA) grades of different molecular weights. Spray-drying studies carried out with the Nano Spray Dryer B-90 employed with piezoelectric driven actuator. The processing parameters including inlet temperature, spray mesh diameter, sample flow rate, spray rate, applied pressure and sample concentration were examined in order to optimize the particle size and the obtained yield. The process parameters and the solute concentration showed a profound effect on the particle engineering and the obtained product yield. The produced powder presented consistent and reproducible spherical particles with narrow particle size distribution. Cyclosporin was found to be molecularly dispersed while dexamethasone was in crystalline state within the PLGA nanoparticles. Further evaluation revealed excellent drug loading, encapsulation efficiency and production yield. In vitro studies demonstrated sustained release patterns for the active substances. This novel spray-drying process proved to be efficient for nano and microparticle engineering of water insoluble active substances. Copyright © 2011 Elsevier B.V. All rights reserved.

An engineering approach to design of dextran microgels size fabricated by water/oil emulsification.

PubMed

Salimi-Kenari, Hamed; Imani, Mohammad; Nodehi, Azizollah; Abedini, Hossein

2016-09-01

A correlation, based on fluid mechanics, has been investigated for the mean particle diameter of crosslinked dextran microgels (CDMs) prepared via a water/oil emulsification methodology conducted in a single-stirred vessel. To this end, non-dimensional correlations were developed to predict the mean particle size of CDMs as a function of Weber number, Reynolds number and viscosity number similar to ones introduced for liquid-liquid dispersions. Moreover, a Rosin-Rammler distribution function has been successfully applied to the microgel particle size distributions. The correlations were validated using experimentally obtained mean particle sizes for CDMs prepared at different stirring conditions. The validated correlation is especially applicable to medical and pharmaceutical applications where strict control on the mean particle size and size distribution of CDMs are extremely essential. [Formula: see text].

40 CFR 1042.310 - Engine selection for Category 1 and Category 2 engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Category 2 engines. (a) Determine minimum sample sizes as follows: (1) For Category 1 engines, the minimum sample size is one engine or one percent of the projected U.S.-directed production volume for all your Category 1 engine families, whichever is greater. (2) For Category 2 engines, the minimum sample size is...

Adaptive Systems Engineering: A Medical Paradigm for Practicing Systems Engineering

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

R. Douglas Hamelin; Ron D. Klingler; Christopher Dieckmann

2011-06-01

From its inception in the defense and aerospace industries, SE has applied holistic, interdisciplinary tools and work-process to improve the design and management of 'large, complex engineering projects.' The traditional scope of engineering in general embraces the design, development, production, and operation of physical systems, and SE, as originally conceived, falls within that scope. While this 'traditional' view has expanded over the years to embrace wider, more holistic applications, much of the literature and training currently available is still directed almost entirely at addressing the large, complex, NASA and defense-sized systems wherein the 'ideal' practice of SE provides the cradle-to-gravemore » foundation for system development and deployment. Under such scenarios, systems engineers are viewed as an integral part of the system and project life-cycle from conception to decommissioning. In far less 'ideal' applications, SE principles are equally applicable to a growing number of complex systems and projects that need to be 'rescued' from overwhelming challenges that threaten imminent failure. The medical profession provides a unique analogy for this latter concept and offers a useful paradigm for tailoring our 'practice' of SE to address the unexpected dynamics of applying SE in the real world. In short, we can be much more effective as systems engineers as we change some of the paradigms under which we teach and 'practice' SE.« less

Application of historical mobility testing to sensor-based robotic performance

NASA Astrophysics Data System (ADS)

Willoughby, William E.; Jones, Randolph A.; Mason, George L.; Shoop, Sally A.; Lever, James H.

2006-05-01

The USA Engineer Research and Development Center (ERDC) has conducted on-/off-road experimental field testing with full-sized and scale-model military vehicles for more than fifty years. Some 4000 acres of local terrain are available for tailored field evaluations or verification/validation of future robotic designs in a variety of climatic regimes. Field testing and data collection procedures, as well as techniques for quantifying terrain in engineering terms, have been developed and refined into algorithms and models for predicting vehicle-terrain interactions and resulting forces or speeds of military-sized vehicles. Based on recent experiments with Matilda, Talon, and Pacbot, these predictive capabilities appear to be relevant to most robotic systems currently in development. Utilization of current testing capabilities with sensor-based vehicle drivers, or use of the procedures for terrain quantification from sensor data, would immediately apply some fifty years of historical knowledge to the development, refinement, and implementation of future robotic systems. Additionally, translation of sensor-collected terrain data into engineering terms would allow assessment of robotic performance a priori deployment of the actual system and ensure maximum system performance in the theater of operation.

Engineering ellipsoidal cap-like hydrogel particles as building blocks or sacrificial templates for three-dimensional cell culture.

PubMed

Zhang, Weiwei; Huang, Guoyou; Ng, Kelvin; Ji, Yuan; Gao, Bin; Huang, Liqing; Zhou, Jinxiong; Lu, Tian Jian; Xu, Feng

2018-03-26

Hydrogel particles that can be engineered to compartmentally culture cells in a three-dimensional (3D) and high-throughput manner have attracted increasing interest in the biomedical area. However, the ability to generate hydrogel particles with specially designed structures and their potential biomedical applications need to be further explored. This work introduces a method for fabricating hydrogel particles in an ellipsoidal cap-like shape (i.e., ellipsoidal cap-like hydrogel particles) by employing an open-pore anodic aluminum oxide membrane. Hydrogel particles of different sizes are fabricated. The ability to produce ellipsoidal cap-like magnetic hydrogel particles with controlled distribution of magnetic nanoparticles is demonstrated. Encapsulated cells show high viability, indicating the potential for using these hydrogel particles as structure- and remote-controllable building blocks for tissue engineering application. Moreover, the hydrogel particles are also used as sacrificial templates for fabricating ellipsoidal cap-like concave wells, which are further applied for producing size controllable cell aggregates. The results are beneficial for the development of hydrogel particles and their applications in 3D cell culture.

Model for determining vapor equilibrium rates in the hanging drop method for protein crystal growth

NASA Technical Reports Server (NTRS)

Baird, James K.; Frieden, Richard W.; Meehan, E. J., Jr.; Twigg, Pamela J.; Howard, Sandra B.; Fowlis, William A.

1987-01-01

An engineering analysis of the rate of evaporation of solvent in the hanging drop method of protein crystal growth is presented. Results are applied to 18 drop and well arrangements commonly encountered in the laboratory. The chemical nature of the salt, drop size and shape, drop concentration, well size, well concentration, and temperature are taken into account. The rate of evaporation increases with temperature, drop size, and the salt concentration difference between the drop and the well. The evaporation in this model possesses no unique half-life. Once the salt in the drop achieves 80 percent of its final concentration, further evaporation suffers from the law of diminishing returns.

Bio-inspired group modeling and analysis for intruder detection in mobile sensor/robotic networks.

PubMed

Fu, Bo; Xiao, Yang; Liang, Xiannuan; Philip Chen, C L

2015-01-01

Although previous bio-inspired models have concentrated on invertebrates (such as ants), mammals such as primates with higher cognitive function are valuable for modeling the increasingly complex problems in engineering. Understanding primates' social and communication systems, and applying what is learned from them to engineering domains is likely to inspire solutions to a number of problems. This paper presents a novel bio-inspired approach to determine group size by researching and simulating primate society. Group size does matter for both primate society and digital entities. It is difficult to determine how to group mobile sensors/robots that patrol in a large area when many factors are considered such as patrol efficiency, wireless interference, coverage, inter/intragroup communications, etc. This paper presents a simulation-based theoretical study on patrolling strategies for robot groups with the comparison of large and small groups through simulations and theoretical results.

Collection of ultrafine diesel particulate matter (DPM) in cylindrical single-stage wet electrostatic precipitators.

PubMed

Saiyasitpanich, Phirun; Keener, Tim C; Lu, Mingming; Khang, Soon-Jai; Evans, Douglas E

2006-12-15

Long-term exposures to diesel particulate matter (DPM) emissions are linked to increasing adverse human health effects due to the potential association of DPM with carcinogenicity. Current diesel vehicular particulate emission regulations are based solely upon total mass concentration, albeit it is the submicrometer particles that are highly respirable and the most detrimental to human health. In this study, experiments were performed with a tubular single-stage wet electrostatic precipitator (wESP) to evaluate its performance for the removal of number-based DPM emissions. A nonroad diesel generator utilizing a low sulfur diesel fuel (500 ppmw) operating under varying load conditions was used as a stationary DPM emission source. An electrical low-pressure impactor (ELPI) was used to quantify the number concentration distributions of diesel particles in the diluted exhaust gas at each tested condition. The wESP was evaluated with respect to different operational control parameters such as applied voltage, gas residence time, etc., to determine their effect on overall collection efficiency, as well as particle size dependent collection efficiency. The results show that the total DPM number concentrations in the untreated diesel exhaust are in the magnitude of approximately108/cm(3) at all engine loads with the particle diameter modes between 20 and 40 nm. The measured collection efficiency of the wESP operating at 70 kV based on total particle numbers was 86% at 0 kW engine load and the efficiency decreased to 67% at 75 kW due to a decrease in gas residence time and an increase in particle concentrations. At a constant wESP voltage of 70 kV and at 75 kW engine load, the variation of gas residence time within the wESP from approximately 0.1 to approximately 0.4 s led to a substantial increase in the collection efficiency from 67% to 96%. In addition, collection efficiency was found to be directly related to the applied voltage, with increasing collection efficiency measured for increases in applied voltage. The collection efficiency based on particle size had a minimum for sizes between 20 and 50 nm, but at optimal wESP operating conditions it was possible to remove over 90% of all particle sizes. A comparison of measured and calculated collection efficiencies reveals that the measured values are significantly higher than the predicted values based on the well-known Deutsch equation.

Hybrid Wing Body Configuration System Studies

NASA Technical Reports Server (NTRS)

Nickol, Craig L.; McCullers, Arnie

2009-01-01

The objective of this study was to develop a hybrid wing body (HWB) sizing and analysis capability, apply that capability to estimate the fuel burn potential for an HWB concept, and identify associated technology requirements. An advanced tube with wings concept was also developed for comparison purposes. NASA s Flight Optimization System (FLOPS) conceptual aircraft sizing and synthesis software was modified to enable the sizing and analysis of HWB concepts. The noncircular pressurized centerbody of the HWB concept was modeled, and several options were created for defining the outboard wing sections. Weight and drag estimation routines were modified to accommodate the unique aspects of an HWB configuration. The resulting capability was then utilized to model a proprietary Boeing blended wing body (BWB) concept for comparison purposes. FLOPS predicted approximately a 15 percent greater drag, mainly caused by differences in compressibility drag estimation, and approximately a 5 percent greater takeoff gross weight, mainly caused by the additional fuel required, as compared with the Boeing data. Next, a 777-like reference vehicle was modeled in FLOPS and calibrated to published Boeing performance data; the same mission definition was used to size an HWB in FLOPS. Advanced airframe and propulsion technology assumptions were applied to the HWB to develop an estimate for potential fuel burn savings from such a concept. The same technology assumptions, where applicable, were then applied to an advanced tube-with-wings concept. The HWB concept had a 39 percent lower block fuel burn than the reference vehicle and a 12 percent lower block fuel burn than the advanced tube-with-wings configuration. However, this fuel burn advantage is partially derived from assuming the high-risk technology of embedded engines with boundary-layer-ingesting inlets. The HWB concept does have the potential for significantly reduced noise as a result of the shielding advantages that are inherent with an over-body engine installation.

Development Status of Reusable Rocket Engine

NASA Astrophysics Data System (ADS)

Yoshida, Makoto; Takada, Satoshi; Naruo, Yoshihiro; Niu, Kenichi

A 30-kN rocket engine, a pilot engine, is being developed in Japan. Development of this pilot engine has been initiated in relation to a reusable sounding rocket, which is also being developed in Japan. This rocket takes off vertically, reaches an altitude of 100 km, lands vertically at the launch site, and is launched again within several days. Due to advantage of reusability, successful development of this rocket will mean that observation missions can be carried out more frequently and economically. In order to realize this rocket concept, the engines installed on the rocket should be characterized by reusability, long life, deep throttling and health monitoring, features which have not yet been established in Japanese rocket engines. To solve the engineering factors entitled by those features, a new design methodology, advanced engine simulations and engineering testing are being focused on in the pilot engine development stage. Especially in engineering testing, limit condition data is acquired to facilitate development of new diagnostic techniques, which can be applied by utilizing the mobility of small-size hardware. In this paper, the development status of the pilot engine is described, including fundamental design and engineering tests of the turbopump bearing and seal, turbine rig, injector and combustion chamber, and operation and maintenance concepts for one hundred flights by a reusable rocket are examined.

Pore architecture and cell viability on freeze dried 3D recombinant human collagen-peptide (RHC)-chitosan scaffolds.

PubMed

Zhang, Jing; Zhou, Aimei; Deng, Aipeng; Yang, Yang; Gao, Lihu; Zhong, Zhaocai; Yang, Shulin

2015-04-01

Pore architecture of 3D scaffolds used in tissue engineering plays a critical role in the maintenance of cell survival, proliferation and further promotion of tissue regeneration. We investigated the pore size and structure, porosity, swelling as well as cell viability of a series of recombinant human collagen-peptide-chitosan (RHCC) scaffolds fabricated by lyophilization. In this paper, freezing regime containing a final temperature of freezing (Tf) and cooling rates was applied to obtain scaffolds with pore size ranging from 100μm to 120μm. Other protocols of RHC/chitosan suspension concentration and ratio modification were studied to produce more homogenous and appropriate structural scaffolds. The mean pore size decreased along with the decline of Tf at a slow cooling rate of 0.7°C/min; a more rapid cooling rate under 5°C/min resulted to a smaller pore size and more homogenous microstructure. High concentration could reduce pore size and lead to thick well of scaffold, while improved the ratio of RHC, lamellar and fiber structure coexisted with cellular pores. Human umbilical vein endothelial cells (HUVECs) were seeded on these manufactured scaffolds, the cell viability represented a negative correlation to the pore size. This study provides an alternative method to fabricate 3D RHC-chitosan scaffolds with appropriate pores for potential tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

Recent advances in engineering microparticles and their nascent utilization in biomedical delivery and diagnostic applications.

PubMed

Choi, Andrew; Seo, Kyoung Duck; Kim, Do Wan; Kim, Bum Chang; Kim, Dong Sung

2017-02-14

Complex microparticles (MPs) bearing unique characteristics such as well-tailored sizes, various morphologies, and multi-compartments have been attempted to be produced by many researchers in the past decades. However, a conventionally used method of fabricating MPs, emulsion polymerization, has a limitation in achieving the aforementioned characteristics and several approaches such as the microfluidics-assisted (droplet-based microfluidics and flow lithography-based microfluidics), electrohydrodynamics (EHD)-based, centrifugation-based, and template-based methods have been recently suggested to overcome this limitation. The outstanding features of complex MPs engineered through these suggested methods have provided new opportunities for MPs to be applied in a wider range of applications including cell carriers, drug delivery agents, active pigments for display, microsensors, interface stabilizers, and catalyst substrates. Overall, the engineered MPs expose their potential particularly in the field of biomedical engineering as the increased complexity in the engineered MPs fulfills well the requirements of the high-end applications. This review outlines the current trends of newly developed techniques used for engineered MPs fabrication and focuses on the current state of engineered MPs in biomedical applications.

Particles from a Diesel ship engine: Mixing state on the nano scale and cloud condensation abilities

NASA Astrophysics Data System (ADS)

Lieke, K. I.; Rosenørn, T.; Fuglsang, K.; Frederiksen, T.; Butcher, A. C.; King, S. M.; Bilde, M.

2012-04-01

Transport by ship plays an important role in global logistics. Current international policy initiatives by the International Maritime Organization (IMO) are taken to reduce emissions from ship propulsion systems (NO and SO, primarily). However, particulate emissions (e.g. soot) from ships are yet not regulated by legislations. To date, there is still a lack of knowledge regarding the global and local effects of the particulate matter emitted from ships at sea. Particles may influence the climate through their direct effects (scattering and absorption of long and shortwave radiation) and indirectly through formation of clouds. Many studies have been carried out estimating the mass and particle number from ship emissions (e.g. Petzold et al. 2008), many of them in test rig studies (e.g. Kasper et al. 2007). It is shown that particulate emissions vary with engine load and chemical composition of fuels. Only a few studies have been carried out to characterize the chemical composition and cloud-nucleating ability of the particulate matter (e.g. Corbett et al. 1997). In most cases, the cloud-nucleating ability of emission particles is estimated from number size distribution. We applied measurements to characterize particulate emissions from a MAN B&W Low Speed engine on test bed. A unique data set was obtained through the use of a scanning mobility particle sizing system (SMPS), combined with a cloud condensation nucleus (CCN) counter and a thermodenuder - all behind a dilution system. In addition, impactor samples were taken on nickel grids with carbon foil for use in an electron microscope (EM) to characterize the mineral phase and mixing state of the particles. The engine was operated at a series of different load conditions and an exhaust gas recirculation (EGR) system was applied. Measurements were carried out before and after the EGR system respectively. Our observations show significant changes in number size distribution and CCN activity with varying conditions. Results of transmission electron microscopy revealed salt condensates of nanometer size attached to soot particles. High resolution structural analysis of single particles shows that three different phases (graphitic soot, crystalline salt and amorphous condensed organic matter) may be present in the same particle volume. A closure between CCN activation curves, EM samples, and SMPS size distribution will be presented and used to identify climate active parts in single particles. ACKNOWLEDGEMENTS We thank the Danish Agency for Science, Technology and Innovation for support through the NaKIM project (www.nakim.dk).

Advanced Main Combustion Chamber structural jacket strength analysis

NASA Astrophysics Data System (ADS)

Johnston, L. M.; Perkins, L. A.; Denniston, C. L.; Price, J. M.

1993-04-01

The structural analysis of the Advanced Main Combustion Chamber (AMCC) is presented. The AMCC is an advanced fabrication concept of the Space Shuttle Main Engine main combustion chamber (MCC). Reduced cost and fabrication time of up to 75 percent were the goals of the AMCC with cast jacket with vacuum plasma sprayed or platelet liner. Since the cast material for the AMCC is much weaker than the wrought material for the MCC, the AMCC is heavier and strength margins much lower in some areas. Proven hand solutions were used to size the manifolds cutout tee areas for combined pressure and applied loads. Detailed finite element strength analyses were used to size the manifolds, longitudinal ribs, and jacket for combined pressure and applied local loads. The design of the gimbal actuator strut attachment lugs were determined by finite element analyses and hand solutions.

Development of a Course of Training Programs for Young Engineers at Work to Nurture the “Basic Competencies of Employees”

NASA Astrophysics Data System (ADS)

Itoh, Michiko; Jomura, Makoto; Hongo, Tetsuyuki; Chohji, Tetsuji

According to our feasibility study in 2005, many of small and medium-sized companies in and around Toyama city asked their young engineers for originality and strong will to try and solve problems positively in their workplaces. These skills have a lot in common with “Basic Competencies of Employees” advocated by the Ministry of Economy, Trade and Industry, Japan. Since Toyama National College of Technology has an accumulated educational know-how to nurture “Basic Competencies of Employees” , we have applied this to develop a course of training programs for young engineers. Through four year‧s practice and improvement, we have established and evaluated this training course. We show the details of our course in this report.

Practice on Upbringing Young Engineers Collaborated with Local Enterprises

NASA Astrophysics Data System (ADS)

Hiraki, Yutaka; Uno, Naotsugu; Tanaka, Yuichi; Iyama, Hirofumi; Yamashita, Toru; Miyamoto, Noritaka

The ministry of Economics and Industry started the project collaborated with National Colleges of Technology titled “Upbringing Young Engineers in small and medium-sized enterprises” , in 2006. In our college, the authors planed the upbringing-program for the die-cast engineer in automobile industries collaborated with several enterprises in neighboring area and applied for the project. The program was adopted and worked out the concrete curriculum for the first year. The curriculum contains the training of the base of mechanical design with 3D-CAD/CAE/CAM systems and the practical training on manufacturing, by means of Problem Based Learning method. The program carried out in September and finished in December successfully. This paper reports the outline of the curriculum and the results in the program.

Feasibility of rotating fluidized bed reactor for rocket propulsion

NASA Technical Reports Server (NTRS)

Ludewig, H.; Manning, A. J.; Raseman, C. J.

1974-01-01

The rotating fluidized bed reactor concept is outlined, and its application to rocket propulsion is discussed. Experimental results obtained indicate that minimum fluidization correlations commonly in use for 1-g beds can also be applied to multiple-g beds. It was found that for a low thrust system (20,000 lbf) the fuel particle size and/or particle stress play a limiting role on performance. The superiority of U-233 as a fuel for this type of rocket engine is clearly demonstrated in the analysis. The maximum thrust/weight ratio for a 90,000N thrust engine was found to be approximately 65N/kg.

The Physical Effects of Detonation in a Closed Cylindrical Chamber

NASA Technical Reports Server (NTRS)

Draper, C S

1935-01-01

Detonation in the internal-combustion engine is studied as a physical process. It is shown that detonation is accompanied by pressure waves within the cylinder charge. Sound theory is applied to the calculation of resonant pressure-wave frequencies. Apparatus is described for direct measurement of pressure-wave frequencies. Frequencies determined from two engines of different cylinder sizes are shown to agree with the values calculated from sound theory. An outline of the theoretically possible modes of vibration in a right circular cylinder with flat ends is included. An appendix by John P. Elting gives a method of calculating pressure in the sound wave following detonation.

Impacts of Venturi Turbulent Mixing on the Size Distributions of Sodium Chloride and Dioctyl-Phthalate Aerosols

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

Cheng, M-D.

2000-08-23

Internal combustion engines are a major source of airborne particulate matter (PM). The size of the engine PM is in the sub-micrometer range. The number of engine particles per unit volume is high, normally in the range of 10{sup 12} to 10{sup 14}. To measure the size distribution of the engine particles dilution of an aerosol sample is required. A diluter utilizing a venturi ejector mixing technique is commercially available and tested. The purpose of this investigation was to determine if turbulence created by the ejector in the mini-dilutor changes the size of particles passing through it. The results ofmore » the NaCl aerosol experiments show no discernible difference in the geometric mean diameter and geometric standard deviation of particles passing through the ejector. Similar results were found for the DOP particles. The ratio of the total number concentrations before and after the ejector indicates that a dilution ratio of approximately 20 applies equally for DOP and NaCl particles. This indicates the dilution capability of the ejector is not affected by the particle composition. The statistical analysis results of the first and second moments of a distribution indicate that the ejector may not change the major parameters (e.g., the geometric mean diameter and geometric standard deviation) characterizing the size distributions of NaCl and DOP particles. However, when the skewness was examined, it indicates that the ejector modifies the particle size distribution significantly. The ejector could change the skewness of the distribution in an unpredictable and inconsistent manner. Furthermore, when the variability of particle counts in individual size ranges as a result of the ejector is examined, one finds that the variability is greater for DOP particles in the size range of 40-150 nm than for NaCl particles in the size range of 30 to 350 nm. The numbers or particle counts in this size region are high enough that the Poisson counting errors are small (<10%) compared with the tail regions. This result shows that the ejector device could have a higher bin-to-bin counting uncertainty for ''soft'' particles such as DOP than for a solid dry particle like NaCl. The results suggest that it may be difficult to precisely characterize the size distribution of particles ejected from the mini-dilution system if the particle is not solid.« less

Finite Element Method (FEM), Mechanobiology and Biomimetic Scaffolds in Bone Tissue Engineering

PubMed Central

Boccaccio, A.; Ballini, A.; Pappalettere, C.; Tullo, D.; Cantore, S.; Desiate, A.

2011-01-01

Techniques of bone reconstructive surgery are largely based on conventional, non-cell-based therapies that rely on the use of durable materials from outside the patient's body. In contrast to conventional materials, bone tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences towards the development of biological substitutes that restore, maintain, or improve bone tissue function. Bone tissue engineering has led to great expectations for clinical surgery or various diseases that cannot be solved with traditional devices. For example, critical-sized defects in bone, whether induced by primary tumor resection, trauma, or selective surgery have in many cases presented insurmountable challenges to the current gold standard treatment for bone repair. The primary purpose of bone tissue engineering is to apply engineering principles to incite and promote the natural healing process of bone which does not occur in critical-sized defects. The total market for bone tissue regeneration and repair was valued at $1.1 billion in 2007 and is projected to increase to nearly $1.6 billion by 2014. Usually, temporary biomimetic scaffolds are utilized for accommodating cell growth and bone tissue genesis. The scaffold has to promote biological processes such as the production of extra-cellular matrix and vascularisation, furthermore the scaffold has to withstand the mechanical loads acting on it and to transfer them to the natural tissues located in the vicinity. The design of a scaffold for the guided regeneration of a bony tissue requires a multidisciplinary approach. Finite element method and mechanobiology can be used in an integrated approach to find the optimal parameters governing bone scaffold performance. In this paper, a review of the studies that through a combined use of finite element method and mechano-regulation algorithms described the possible patterns of tissue differentiation in biomimetic scaffolds for bone tissue engineering is given. Firstly, the generalities of the finite element method of structural analysis are outlined; second, the issues related to the generation of a finite element model of a given anatomical site or of a bone scaffold are discussed; thirdly, the principles on which mechanobiology is based, the principal theories as well as the main applications of mechano-regulation models in bone tissue engineering are described; finally, the limitations of the mechanobiological models and the future perspectives are indicated. PMID:21278921

Predictions of Transient Flame Lift-Off Length With Comparison to Single-Cylinder Optical Engine Experiments

DOE PAGES

Senecal, P. K.; Pomraning, E.; Anders, J. W.; ...

2014-05-28

A state-of-the-art, grid-convergent simulation methodology was applied to three-dimensional calculations of a single-cylinder optical engine. A mesh resolution study on a sector-based version of the engine geometry further verified the RANS-based cell size recommendations previously presented by Senecal et al. (“Grid Convergent Spray Models for Internal Combustion Engine CFD Simulations,” ASME Paper No. ICEF2012-92043). Convergence of cylinder pressure, flame lift-off length, and emissions was achieved for an adaptive mesh refinement cell size of 0.35 mm. Furthermore, full geometry simulations, using mesh settings derived from the grid convergence study, resulted in excellent agreement with measurements of cylinder pressure, heat release rate,more » and NOx emissions. On the other hand, the full geometry simulations indicated that the flame lift-off length is not converged at 0.35 mm for jets not aligned with the computational mesh. Further simulations suggested that the flame lift-off lengths for both the nonaligned and aligned jets appear to be converged at 0.175 mm. With this increased mesh resolution, both the trends and magnitudes in flame lift-off length were well predicted with the current simulation methodology. Good agreement between the overall predicted flame behavior and the available chemiluminescence measurements was also achieved. Our present study indicates that cell size requirements for accurate prediction of full geometry flame lift-off lengths may be stricter than those for global combustion behavior. This may be important when accurate soot predictions are required.« less

Predictions of Transient Flame Lift-Off Length With Comparison to Single-Cylinder Optical Engine Experiments

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

Senecal, P. K.; Pomraning, E.; Anders, J. W.

A state-of-the-art, grid-convergent simulation methodology was applied to three-dimensional calculations of a single-cylinder optical engine. A mesh resolution study on a sector-based version of the engine geometry further verified the RANS-based cell size recommendations previously presented by Senecal et al. (“Grid Convergent Spray Models for Internal Combustion Engine CFD Simulations,” ASME Paper No. ICEF2012-92043). Convergence of cylinder pressure, flame lift-off length, and emissions was achieved for an adaptive mesh refinement cell size of 0.35 mm. Furthermore, full geometry simulations, using mesh settings derived from the grid convergence study, resulted in excellent agreement with measurements of cylinder pressure, heat release rate,more » and NOx emissions. On the other hand, the full geometry simulations indicated that the flame lift-off length is not converged at 0.35 mm for jets not aligned with the computational mesh. Further simulations suggested that the flame lift-off lengths for both the nonaligned and aligned jets appear to be converged at 0.175 mm. With this increased mesh resolution, both the trends and magnitudes in flame lift-off length were well predicted with the current simulation methodology. Good agreement between the overall predicted flame behavior and the available chemiluminescence measurements was also achieved. Our present study indicates that cell size requirements for accurate prediction of full geometry flame lift-off lengths may be stricter than those for global combustion behavior. This may be important when accurate soot predictions are required.« less

Evaporation kinetics in the hanging drop method of protein crystal growth

NASA Technical Reports Server (NTRS)

Baird, James K.; Frieden, Richard W.; Meehan, E. J., Jr.; Twigg, Pamela J.; Howard, Sandra B.; Fowlis, William A.

1987-01-01

An engineering analysis of the rate of evaporation of solvent in the hanging drop method of protein crystal growth is presented; these results are applied to 18 different drop and well arrangements commonly encountered in the laboratory, taking into account the chemical nature of the salt, the drop size and shape, the drop concentration, the well size, the well concentration, and the temperature. It is found that the rate of evaporation increases with temperature, drop size, and with the salt concentration difference between the drop and the well. The evaporation possesses no unique half-life. Once the salt in the drop achieves about 80 percent of its final concentration, further evaporation suffers from the law of diminishing returns.

Knowledge base methodology: Methodology for first Engineering Script Language (ESL) knowledge base

NASA Technical Reports Server (NTRS)

Peeris, Kumar; Izygon, Michel E.

1992-01-01

The primary goal of reusing software components is that software can be developed faster, cheaper and with higher quality. Though, reuse is not automatic and can not just happen. It has to be carefully engineered. For example a component needs to be easily understandable in order to be reused, and it has also to be malleable enough to fit into different applications. In fact the software development process is deeply affected when reuse is being applied. During component development, a serious effort has to be directed toward making these components as reusable. This implies defining reuse coding style guidelines and applying then to any new component to create as well as to any old component to modify. These guidelines should point out the favorable reuse features and may apply to naming conventions, module size and cohesion, internal documentation, etc. During application development, effort is shifted from writing new code toward finding and eventually modifying existing pieces of code, then assembling them together. We see here that reuse is not free, and therefore has to be carefully managed.

A survey of methods for the evaluation of tissue engineering scaffold permeability.

PubMed

Pennella, F; Cerino, G; Massai, D; Gallo, D; Falvo D'Urso Labate, G; Schiavi, A; Deriu, M A; Audenino, A; Morbiducci, Umberto

2013-10-01

The performance of porous scaffolds for tissue engineering (TE) applications is evaluated, in general, in terms of porosity, pore size and distribution, and pore tortuosity. These descriptors are often confounding when they are applied to characterize transport phenomena within porous scaffolds. On the contrary, permeability is a more effective parameter in (1) estimating mass and species transport through the scaffold and (2) describing its topological features, thus allowing a better evaluation of the overall scaffold performance. However, the evaluation of TE scaffold permeability suffers of a lack of uniformity and standards in measurement and testing procedures which makes the comparison of results obtained in different laboratories unfeasible. In this review paper we summarize the most important features influencing TE scaffold permeability, linking them to the theoretical background. An overview of methods applied for TE scaffold permeability evaluation is given, presenting experimental test benches and computational methods applied (1) to integrate experimental measurements and (2) to support the TE scaffold design process. Both experimental and computational limitations in the permeability evaluation process are also discussed.

RNAslider: a faster engine for consecutive windows folding and its application to the analysis of genomic folding asymmetry.

PubMed

Horesh, Yair; Wexler, Ydo; Lebenthal, Ilana; Ziv-Ukelson, Michal; Unger, Ron

2009-03-04

Scanning large genomes with a sliding window in search of locally stable RNA structures is a well motivated problem in bioinformatics. Given a predefined window size L and an RNA sequence S of size N (L < N), the consecutive windows folding problem is to compute the minimal free energy (MFE) for the folding of each of the L-sized substrings of S. The consecutive windows folding problem can be naively solved in O(NL3) by applying any of the classical cubic-time RNA folding algorithms to each of the N-L windows of size L. Recently an O(NL2) solution for this problem has been described. Here, we describe and implement an O(NLpsi(L)) engine for the consecutive windows folding problem, where psi(L) is shown to converge to O(1) under the assumption of a standard probabilistic polymer folding model, yielding an O(L) speedup which is experimentally confirmed. Using this tool, we note an intriguing directionality (5'-3' vs. 3'-5') folding bias, i.e. that the minimal free energy (MFE) of folding is higher in the native direction of the DNA than in the reverse direction of various genomic regions in several organisms including regions of the genomes that do not encode proteins or ncRNA. This bias largely emerges from the genomic dinucleotide bias which affects the MFE, however we see some variations in the folding bias in the different genomic regions when normalized to the dinucleotide bias. We also present results from calculating the MFE landscape of a mouse chromosome 1, characterizing the MFE of the long ncRNA molecules that reside in this chromosome. The efficient consecutive windows folding engine described in this paper allows for genome wide scans for ncRNA molecules as well as large-scale statistics. This is implemented here as a software tool, called RNAslider, and applied to the scanning of long chromosomes, leading to the observation of features that are visible only on a large scale.

Method and device for feeding fuel in a fuel system

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

Williamson, E.

1988-07-26

This patent describes a device for feeding fuel in a fuel system for a liquid fuel engine, with the fuel system having a fuel tank, fuel lines, multiple microscreen fuel filters, a fuel pump, and engine fuel injectors, with the fuel tank having a fill opening having a perimeter, comprising, in combination: a ball having a size for overfitting and abutting with the perimeter of the fill opening of differing sizes, shapes, and constructions; and means for introducing air pressure greater than atmospheric through the ball and through the fill opening and into the fuel tank, with the ball havingmore » a solid cross section and being generally impermeable to air passage, with the ball being deformable to conform to the perimeter of the fill opening for sealingly engaging the perimeter of the fill opening and having a firmness for transmitting a force applied to the ball in the direction of the fill opening into a sealing force applied by the ball to the fill opening to balance opposing forces created by the introduction of air pressure into the fuel tank and for increasing the air pressure in the fuel tank acting on the fuel to increase the rate of fuel flow from the fuel tank into the fuel line for assisting the fuel pump in moving the fuel from the fuel tank through the fuel lines and through the microscreen filters to the engine fuel injectors while allowing an excessive air pressure to escape from the fill opening around the ball.« less

Enhanced centrifuge-based approach to powder characterization

NASA Astrophysics Data System (ADS)

Thomas, Myles Calvin

Many types of manufacturing processes involve powders and are affected by powder behavior. It is highly desirable to implement tools that allow the behavior of bulk powder to be predicted based on the behavior of only small quantities of powder. Such descriptions can enable engineers to significantly improve the performance of powder processing and formulation steps. In this work, an enhancement of the centrifuge technique is proposed as a means of powder characterization. This enhanced method uses specially designed substrates with hemispherical indentations within the centrifuge. The method was tested using simulations of the momentum balance at the substrate surface. Initial simulations were performed with an ideal powder containing smooth, spherical particles distributed on substrates designed with indentations. The van der Waals adhesion between the powder, whose size distribution was based on an experimentally-determined distribution from a commercial silica powder, and the indentations was calculated and compared to the removal force created in the centrifuge. This provided a way to relate the powder size distribution to the rotational speed required for particle removal for various indentation sizes. Due to the distinct form of the data from these simulations, the cumulative size distribution of the powder and the Hamaker constant for the system were be extracted. After establishing adhesion force characterization for an ideal powder, the same proof-of-concept procedure was followed for a more realistic system with a simulated rough powder modeled as spheres with sinusoidal protrusions and intrusions around the surface. From these simulations, it was discovered that an equivalent powder of smooth spherical particles could be used to describe the adhesion behavior of the rough spherical powder by establishing a size-dependent 'effective' Hamaker constant distribution. This development made it possible to describe the surface roughness effects of the entire powder through one adjustable parameter that was linked to the size distribution. It is important to note that when the engineered substrates (hemispherical indentations) were applied, it was possible to extract both powder size distribution and effective Hamaker constant information from the simulated centrifuge adhesion experiments. Experimental validation of the simulated technique was performed with a silica powder dispersed onto a stainless steel substrate with no engineered surface features. Though the proof-of-concept work was accomplished for indented substrates, non-ideal, relatively flat (non-indented) substrates were used experimentally to demonstrate that the technique can be extended to this case. The experimental data was then used within the newly developed simulation procedure to show its application to real systems. In the absence of engineered features on the substrates, it was necessary to specify the size distribution of the powder as an input to the simulator. With this information, it was possible to extract an effective Hamaker constant distribution and when the effective Hamaker constant distribution was applied in conjunction with the size distribution, the observed adhesion force distribution was described precisely. An equation was developed that related the normalized effective Hamaker constants (normalized by the particle diameter) to the particle diameter was formulated from the effective Hamaker constant distribution. It was shown, by application of the equation, that the adhesion behavior of an ideal (smooth, spherical) powder with an experimentally-validated, effective Hamaker constant distribution could be used to effectively represent that of a realistic powder. Thus, the roughness effects and size variations of a real powder are captured in this one distributed parameter (effective Hamaker constant distribution) which provides a substantial improvement to the existing technique. This can lead to better optimization of powder processing by enhancing powder behavior models.

Scramjet nozzle design and analysis as applied to a highly integrated hypersonic research airplane

NASA Technical Reports Server (NTRS)

Small, W. J.; Weidner, J. P.; Johnston, P. J.

1974-01-01

The configuration and performance of the propulsion system for the hypersonic research vehicle are discussed. A study of the interactions between propulsion and aerodynamics of the highly integrated vehicle was conducted. The hypersonic research vehicle is configured to test the technology of structural and thermal protection systems concepts and the operation of the propulsion system under true flight conditions for most of the hypersonic flight regime. The subjects considered are: (1) research vehicle and scramjet engine configurations to determine fundamental engine sizing constraints, (2) analytical methods for computing airframe and propulsion system components, and (3) characteristics of a candidate nozzle to investigate vehicle stability and acceleration performance.

Definition of 1992 Technology Aircraft Noise Levels and the Methodology for Assessing Airplane Noise Impact of Component Noise Reduction Concepts

NASA Technical Reports Server (NTRS)

Kumasaka, Henry A.; Martinez, Michael M.; Weir, Donald S.

1996-01-01

This report describes the methodology for assessing the impact of component noise reduction on total airplane system noise. The methodology is intended to be applied to the results of individual study elements of the NASA-Advanced Subsonic Technology (AST) Noise Reduction Program, which will address the development of noise reduction concepts for specific components. Program progress will be assessed in terms of noise reduction achieved, relative to baseline levels representative of 1992 technology airplane/engine design and performance. In this report, the 1992 technology reference levels are defined for assessment models based on four airplane sizes - an average business jet and three commercial transports: a small twin, a medium sized twin, and a large quad. Study results indicate that component changes defined as program final goals for nacelle treatment and engine/airframe source noise reduction would achieve from 6-7 EPNdB reduction of total airplane noise at FAR 36 Stage 3 noise certification conditions for all of the airplane noise assessment models.

Constitutive and Stability Behavior of Soils in Microgravity Environment

NASA Technical Reports Server (NTRS)

Alshibli, Khalid A.; Sture, Stein; Costes, Nicholas

2000-01-01

All aspects of soil stability, bearing capacity, slope stability, the supporting capacity of deep foundations, and penetration resistance depend on soil strength. The stress-deformation and stress-deformation-time behavior of soils are of importance in any problem where ground movements are of interest. In most engineering materials, the strength is derived from internal chemical and physico-chemical forces of interaction, which bond the atoms, molecules, and particles together. In soils, the constitutive relations are mainly derived from interparticle friction between particles and particle groups and dilatancy, and to a lesser extent from particle bonding by weak electrostatic, physico-chemical, and coulomb forces. For engineering purposes, soils are classified as cohesive (clays and silts; typical particle sizes range from 10 nm to 10 micrometers) and cohesionless (sand and gravel; typical particle sizes range from 10 micrometers to 75 mm). The mechanical or constitutive properties of cohesionless soils or granular materials are highly fabric-dependent, highly non-linear, and non-conservative with engineering properties primarily depending on the effects of gravity through self-weight and on the tractions or forces applied to the soil mass. Under moderate-to-high stress levels, the influence of gravity on the behavior of laboratory test specimens may not be pronounced and, therefore, the test results in terrestrial (1-g) environment may be sufficiently conclusive. However at low interparticle stresses, which can result either from low applied (confining) stresses or from excess pore fluid pressures developed within the soil mass without corresponding changes in the applied stresses, the presence of gravitational body forces acting on solid particles and interstitial fluids exerts a pronounced influence on movement of individual particles or particle groups. Such motions, in turn, cause changes in soil fabric which results in significant changes in the interparticle friction forces contributing to the soil's strength and deformation characteristics.

Computer-Aided Process Model For Carbon/Phenolic Materials

NASA Technical Reports Server (NTRS)

Letson, Mischell A.; Bunker, Robert C.

1996-01-01

Computer program implements thermochemical model of processing of carbon-fiber/phenolic-matrix composite materials into molded parts of various sizes and shapes. Directed toward improving fabrication of rocket-engine-nozzle parts, also used to optimize fabrication of other structural components, and material-property parameters changed to apply to other materials. Reduces costs by reducing amount of laboratory trial and error needed to optimize curing processes and to predict properties of cured parts.

Performance of engine-driven rotary endodontic instruments with a superimposed bending deflection: V. Gates Glidden and Peeso drills.

PubMed

Brantley, W A; Luebke, N H; Luebke, F L; Mitchell, J C

1994-05-01

A laboratory study was performed on Gates Glidden and Peeso drills to determine the incidence of shaft fracture when a bending deflection was superimposed on the rotating drills. Samples of sizes #1 to #6 stainless steel Gates Glidden drills, sizes #1 to #6 stainless steel and carbon steel-type P Peeso drills, and sizes #009 to #023 carbon steel-type B-1 Peeso drills from each of two manufacturers were evaluated with a unique apparatus that applied a 2-mm bending deflection while rotating the instruments. The apparatus did not restrict movement of the bur head during rotation. The test drills were rotated at 2500, 4000, and 7000 revolutions per minute, and the number of revolutions at failure was recorded. Scanning electron microscopic observations established that the stainless steel Gates Glidden and Peeso drills failed by ductile fracture, whereas the carbon steel Peeso drills failed by brittle fracture. Instrument fracture was always near the handpiece shank with this test, and the length of the fractured drills was measured from the working tip. It is recommended that this additional test be adopted to determine fatigue properties of engine-driven rotary endodontic instruments in establishing international performance standards.

Correlation between electrical, mechanical and chemical properties of fresh and used aircraft engine oils

NASA Astrophysics Data System (ADS)

Gajewski, Juliusz B.; Głogowski, Marek J.; Paszkowski, Maciej; Czarnik-Matusewicz, Bogusława

2011-06-01

In this paper the results are presented of measurements of electrical, mechanical and chemical properties of fresh and used aircraft engine oils. Oils were used in a four-stroke aircraft engine and their samples were taken after the 50-hour work of the engine. The resistivity, permittivity and viscosity of oils were measured as a function of temperature. Additionally, some measurements of the absorbance spectra and size of particles contained in the oils were carried out. The significant reduction in the resistivity of the used Total oil was observed. The relative permittivity of both used oils was slightly increased. The oil's relative viscosity depends on temperature of oil and given time that elapsed from the very first moment when the shear force was applied in a rheometer. The results obtained allowed one to identify more precisely the chemical and physico-chemical interactions occurring in the tested samples, as compared with a typical infrared spectroscopy.

Molecular engineering with artificial atoms: designing a material platform for scalable quantum spintronics and photonics

NASA Astrophysics Data System (ADS)

Doty, Matthew F.; Ma, Xiangyu; Zide, Joshua M. O.; Bryant, Garnett W.

2017-09-01

Self-assembled InAs Quantum Dots (QDs) are often called "artificial atoms" and have long been of interest as components of quantum photonic and spintronic devices. Although there has been substantial progress in demonstrating optical control of both single spins confined to a single QD and entanglement between two separated QDs, the path toward scalable quantum photonic devices based on spins remains challenging. Quantum Dot Molecules, which consist of two closely-spaced InAs QDs, have unique properties that can be engineered with the solid state analog of molecular engineering in which the composition, size, and location of both the QDs and the intervening barrier are controlled during growth. Moreover, applied electric, magnetic, and optical fields can be used to modulate, in situ, both the spin and optical properties of the molecular states. We describe how the unique photonic properties of engineered Quantum Dot Molecules can be leveraged to overcome long-standing challenges to the creation of scalable quantum devices that manipulate single spins via photonics.

Engine sizing and integration requirements for hypersonic airbreathing missile applications

NASA Astrophysics Data System (ADS)

Waltrup, P. J.; Billig, F. S.; Stockbridge, R. D.

1982-03-01

A procedure that provides a rational means for selecting an inlet/combustor configuration for a hypersonic airbreathing missile is presented. The particular problem that is addressed is the design of the sustained engine of a two stage missile that is constrained to be launched from a stowage volume that is either square or circular in cross section. The sustainer engine accelerates from a low altitude separation at Mach 4 and climbs to high altitude for cruise at Mach 8. The results show that a missile with an axisymmetric nose inlet provides a somewhat higher thrust capability and slightly better fuel efficiency than a chin type inlet. Aft entry inlets are shown to have a substantially lower thrust potential and lower engine efficiency. A criterion for determining the maximum contraction ratio of a fixed geometry inlet is established and applied to the exemplary missile designs. Combustor area ratio is examined and found to have a relatively small effect on engine performance for area ratios equal to or larger than that required to obtain maximum thrust at the take-over Mach number.

Application of real rock pore-threat statistics to a regular pore network model

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

Rakibul, M.; Sarker, H.; McIntyre, D.

2011-01-01

This work reports the application of real rock statistical data to a previously developed regular pore network model in an attempt to produce an accurate simulation tool with low computational overhead. A core plug from the St. Peter Sandstone formation in Indiana was scanned with a high resolution micro CT scanner. The pore-throat statistics of the three-dimensional reconstructed rock were extracted and the distribution of the pore-throat sizes was applied to the regular pore network model. In order to keep the equivalent model regular, only the throat area or the throat radius was varied. Ten realizations of randomly distributed throatmore » sizes were generated to simulate the drainage process and relative permeability was calculated and compared with the experimentally determined values of the original rock sample. The numerical and experimental procedures are explained in detail and the performance of the model in relation to the experimental data is discussed and analyzed. Petrophysical properties such as relative permeability are important in many applied fields such as production of petroleum fluids, enhanced oil recovery, carbon dioxide sequestration, ground water flow, etc. Relative permeability data are used for a wide range of conventional reservoir engineering calculations and in numerical reservoir simulation. Two-phase oil water relative permeability data are generated on the same core plug from both pore network model and experimental procedure. The shape and size of the relative permeability curves were compared and analyzed and good match has been observed for wetting phase relative permeability but for non-wetting phase, simulation results were found to be deviated from the experimental ones. Efforts to determine petrophysical properties of rocks using numerical techniques are to eliminate the necessity of regular core analysis, which can be time consuming and expensive. So a numerical technique is expected to be fast and to produce reliable results. In applied engineering, sometimes quick result with reasonable accuracy is acceptable than the more time consuming results. Present work is an effort to check the accuracy and validity of a previously developed pore network model for obtaining important petrophysical properties of rocks based on cutting-sized sample data.« less

Application of real rock pore-throat statistics to a regular pore network model

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

Sarker, M.R.; McIntyre, D.; Ferer, M.

2011-01-01

This work reports the application of real rock statistical data to a previously developed regular pore network model in an attempt to produce an accurate simulation tool with low computational overhead. A core plug from the St. Peter Sandstone formation in Indiana was scanned with a high resolution micro CT scanner. The pore-throat statistics of the three-dimensional reconstructed rock were extracted and the distribution of the pore-throat sizes was applied to the regular pore network model. In order to keep the equivalent model regular, only the throat area or the throat radius was varied. Ten realizations of randomly distributed throatmore » sizes were generated to simulate the drainage process and relative permeability was calculated and compared with the experimentally determined values of the original rock sample. The numerical and experimental procedures are explained in detail and the performance of the model in relation to the experimental data is discussed and analyzed. Petrophysical properties such as relative permeability are important in many applied fields such as production of petroleum fluids, enhanced oil recovery, carbon dioxide sequestration, ground water flow, etc. Relative permeability data are used for a wide range of conventional reservoir engineering calculations and in numerical reservoir simulation. Two-phase oil water relative permeability data are generated on the same core plug from both pore network model and experimental procedure. The shape and size of the relative permeability curves were compared and analyzed and good match has been observed for wetting phase relative permeability but for non-wetting phase, simulation results were found to be deviated from the experimental ones. Efforts to determine petrophysical properties of rocks using numerical techniques are to eliminate the necessity of regular core analysis, which can be time consuming and expensive. So a numerical technique is expected to be fast and to produce reliable results. In applied engineering, sometimes quick result with reasonable accuracy is acceptable than the more time consuming results. Present work is an effort to check the accuracy and validity of a previously developed pore network model for obtaining important petrophysical properties of rocks based on cutting-sized sample data. Introduction« less

Quantifying the motion of magnetic particles in excised tissue: Effect of particle properties and applied magnetic field

NASA Astrophysics Data System (ADS)

Kulkarni, Sandip; Ramaswamy, Bharath; Horton, Emily; Gangapuram, Sruthi; Nacev, Alek; Depireux, Didier; Shimoji, Mika; Shapiro, Benjamin

2015-11-01

This article presents a method to investigate how magnetic particle characteristics affect their motion inside tissues under the influence of an applied magnetic field. Particles are placed on top of freshly excised tissue samples, a calibrated magnetic field is applied by a magnet underneath each tissue sample, and we image and quantify particle penetration depth by quantitative metrics to assess how particle sizes, their surface coatings, and tissue resistance affect particle motion. Using this method, we tested available fluorescent particles from Chemicell of four sizes (100 nm, 300 nm, 500 nm, and 1 μm diameter) with four different coatings (starch, chitosan, lipid, and PEG/P) and quantified their motion through freshly excised rat liver, kidney, and brain tissues. In broad terms, we found that the applied magnetic field moved chitosan particles most effectively through all three tissue types (as compared to starch, lipid, and PEG/P coated particles). However, the relationship between particle properties and their resulting motion was found to be complex. Hence, it will likely require substantial further study to elucidate the nuances of transport mechanisms and to select and engineer optimal particle properties to enable the most effective transport through various tissue types under applied magnetic fields.

Earthquake Damage Assessment Using Very High Resolution Satelliteimagery

NASA Astrophysics Data System (ADS)

Chiroiu, L.; André, G.; Bahoken, F.; Guillande, R.

Various studies using satellite imagery were applied in the last years in order to assess natural hazard damages, most of them analyzing the case of floods, hurricanes or landslides. For the case of earthquakes, the medium or small spatial resolution data available in the recent past did not allow a reliable identification of damages, due to the size of the elements (e.g. buildings or other structures), too small compared with the pixel size. The recent progresses of remote sensing in terms of spatial resolution and data processing makes possible a reliable damage detection to the elements at risk. Remote sensing techniques applied to IKONOS (1 meter resolution) and IRS (5 meters resolution) imagery were used in order to evaluate seismic vulnerability and post earthquake damages. A fast estimation of losses was performed using a multidisciplinary approach based on earthquake engineering and geospatial analysis. The results, integrated into a GIS database, could be transferred via satellite networks to the rescue teams deployed on the affected zone, in order to better coordinate the emergency operations. The methodology was applied to the city of Bhuj and Anjar after the 2001 Gujarat (India) Earthquake.

40 CFR 94.505 - Sample selection for testing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engine family. The required sample size is zero if a manufacturer's projected annual production for all Category 1 engine families is less than 100. (ii) The required sample size for a Category 2 engine family... manufacturer will begin to select engines from each Category 1 and Category 2 engine family for production line...

Human Systems Integration Competency Development for Navy Systems Commands

DTIC Science & Technology

2012-09-01

cognizance of Applied Engineering /Psychology relative to knowledge engineering, training, teamwork, user interface design and decision sciences. KSA...cognizance of Applied Engineering /Psychology relative to knowledge engineering, training, teamwork, user interface design and decision sciences...requirements (as required). Fundamental cognizance of Applied Engineering / Psychology relative to knowledge engineering, training, team work, user

Water supply pipe dimensioning using hydraulic power dissipation

NASA Astrophysics Data System (ADS)

Sreemathy, J. R.; Rashmi, G.; Suribabu, C. R.

2017-07-01

Proper sizing of the pipe component of water distribution networks play an important role in the overall design of the any water supply system. Several approaches have been applied for the design of networks from an economical point of view. Traditional optimization techniques and population based stochastic algorithms are widely used to optimize the networks. But the use of these approaches is mostly found to be limited to the research level due to difficulties in understanding by the practicing engineers, design engineers and consulting firms. More over due to non-availability of commercial software related to the optimal design of water distribution system,it forces the practicing engineers to adopt either trial and error or experience-based design. This paper presents a simple approach based on power dissipation in each pipeline as a parameter to design the network economically, but not to the level of global minimum cost.

Efficiency at maximum power of a chemical engine.

PubMed

Hooyberghs, Hans; Cleuren, Bart; Salazar, Alberto; Indekeu, Joseph O; Van den Broeck, Christian

2013-10-07

A cyclically operating chemical engine is considered that converts chemical energy into mechanical work. The working fluid is a gas of finite-sized spherical particles interacting through elastic hard collisions. For a generic transport law for particle uptake and release, the efficiency at maximum power η(mp) [corrected] takes the form 1/2+cΔμ+O(Δμ(2)), with 1∕2 a universal constant and Δμ the chemical potential difference between the particle reservoirs. The linear coefficient c is zero for engines featuring a so-called left/right symmetry or particle fluxes that are antisymmetric in the applied chemical potential difference. Remarkably, the leading constant in η(mp) [corrected] is non-universal with respect to an exceptional modification of the transport law. For a nonlinear transport model, we obtain η(mp) = 1/(θ + 1) [corrected], with θ > 0 the power of Δμ in the transport equation.

Influence of fuel injection timing and pressure on in-flame soot particles in an automotive-size diesel engine.

PubMed

Zhang, Renlin; Kook, Sanghoon

2014-07-15

The current understanding of soot particle morphology in diesel engines and their dependency on the fuel injection timing and pressure is limited to those sampled from the exhaust. In this study, a thermophoretic sampling and subsequent transmission electron microscope imaging were applied to the in-flame soot particles inside the cylinder of a working diesel engine for various fuel injection timings and pressures. The results show that the number count of soot particles per image decreases by more than 80% when the injection timing is retarded from -12 to -2 crank angle degrees after the top dead center. The late injection also results in over 90% reduction of the projection area of soot particles on the TEM image and the size of soot aggregates also become smaller. The primary particle size, however, is found to be insensitive to the variations in fuel injection timing. For injection pressure variations, both the size of primary particles and soot aggregates are found to decrease with increasing injection pressure, demonstrating the benefits of high injection velocity and momentum. Detailed analysis shows that the number count of soot particles per image increases with increasing injection pressure up to 130 MPa, primarily due to the increased small particle aggregates that are less than 40 nm in the radius of gyration. The fractal dimension shows an overall decrease with the increasing injection pressure. However, there is a case that the fractal dimension shows an unexpected increase between 100 and 130 MPa injection pressure. It is because the small aggregates with more compact and agglomerated structures outnumber the large aggregates with more stretched chain-like structures.

Reduction of Sample Size Requirements by Bilateral Versus Unilateral Research Designs in Animal Models for Cartilage Tissue Engineering

PubMed Central

Orth, Patrick; Zurakowski, David; Alini, Mauro; Cucchiarini, Magali

2013-01-01

Advanced tissue engineering approaches for articular cartilage repair in the knee joint rely on translational animal models. In these investigations, cartilage defects may be established either in one joint (unilateral design) or in both joints of the same animal (bilateral design). We hypothesized that a lower intraindividual variability following the bilateral strategy would reduce the number of required joints. Standardized osteochondral defects were created in the trochlear groove of 18 rabbits. In 12 animals, defects were produced unilaterally (unilateral design; n=12 defects), while defects were created bilaterally in 6 animals (bilateral design; n=12 defects). After 3 weeks, osteochondral repair was evaluated histologically applying an established grading system. Based on intra- and interindividual variabilities, required sample sizes for the detection of discrete differences in the histological score were determined for both study designs (α=0.05, β=0.20). Coefficients of variation (%CV) of the total histological score values were 1.9-fold increased following the unilateral design when compared with the bilateral approach (26 versus 14%CV). The resulting numbers of joints needed to treat were always higher for the unilateral design, resulting in an up to 3.9-fold increase in the required number of experimental animals. This effect was most pronounced for the detection of small-effect sizes and estimating large standard deviations. The data underline the possible benefit of bilateral study designs for the decrease of sample size requirements for certain investigations in articular cartilage research. These findings might also be transferred to other scoring systems, defect types, or translational animal models in the field of cartilage tissue engineering. PMID:23510128

The evolution of helicopters

NASA Astrophysics Data System (ADS)

Chen, R.; Wen, C. Y.; Lorente, S.; Bejan, A.

2016-07-01

Here, we show that during their half-century history, helicopters have been evolving into geometrically similar architectures with surprisingly sharp correlations between dimensions, performance, and body size. For example, proportionalities emerge between body size, engine size, and the fuel load. Furthermore, the engine efficiency increases with the engine size, and the propeller radius is roughly the same as the length scale of the whole body. These trends are in accord with the constructal law, which accounts for the engine efficiency trend and the proportionality between "motor" size and body size in animals and vehicles. These body-size effects are qualitatively the same as those uncovered earlier for the evolution of aircraft. The present study adds to this theoretical body of research the evolutionary design of all technologies [A. Bejan, The Physics of Life: The Evolution of Everything (St. Martin's Press, New York, 2016)].

Equations for hydraulic conductivity estimation from particle size distribution: A dimensional analysis

NASA Astrophysics Data System (ADS)

Wang, Ji-Peng; François, Bertrand; Lambert, Pierre

2017-09-01

Estimating hydraulic conductivity from particle size distribution (PSD) is an important issue for various engineering problems. Classical models such as Hazen model, Beyer model, and Kozeny-Carman model usually regard the grain diameter at 10% passing (d10) as an effective grain size and the effects of particle size uniformity (in Beyer model) or porosity (in Kozeny-Carman model) are sometimes embedded. This technical note applies the dimensional analysis (Buckingham's ∏ theorem) to analyze the relationship between hydraulic conductivity and particle size distribution (PSD). The porosity is regarded as a dependent variable on the grain size distribution in unconsolidated conditions. It indicates that the coefficient of grain size uniformity and a dimensionless group representing the gravity effect, which is proportional to the mean grain volume, are the main two determinative parameters for estimating hydraulic conductivity. Regression analysis is then carried out on a database comprising 431 samples collected from different depositional environments and new equations are developed for hydraulic conductivity estimation. The new equation, validated in specimens beyond the database, shows an improved prediction comparing to using the classic models.

Uniform-droplet spray forming

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

Blue, C.A.; Sikka, V.K.; Chun, Jung-Hoon

1997-04-01

The uniform-droplet process is a new method of liquid-metal atomization that results in single droplets that can be used to produce mono-size powders or sprayed-on to substrates to produce near-net shapes with tailored microstructure. The mono-sized powder-production capability of the uniform-droplet process also has the potential of permitting engineered powder blends to produce components of controlled porosity. Metal and alloy powders are commercially produced by at least three different methods: gas atomization, water atomization, and rotating disk. All three methods produce powders of a broad range in size with a very small yield of fine powders with single-sized droplets thatmore » can be used to produce mono-size powders or sprayed-on substrates to produce near-net shapes with tailored microstructures. The economical analysis has shown the process to have the potential of reducing capital cost by 50% and operating cost by 37.5% when applied to powder making. For the spray-forming process, a 25% savings is expected in both the capital and operating costs. The project is jointly carried out at Massachusetts Institute of Technology (MIT), Tuffs University, and Oak Ridge National Laboratory (ORNL). Preliminary interactions with both finished parts and powder producers have shown a strong interest in the uniform-droplet process. Systematic studies are being conducted to optimize the process parameters, understand the solidification of droplets and spray deposits, and develop a uniform-droplet-system (UDS) apparatus appropriate for processing engineering alloys.« less

NASA Puffin Electric Tailsitter VTOL Concept

NASA Technical Reports Server (NTRS)

Moore, Mark D.

2010-01-01

Electric propulsion offers dramatic new vehicle mission capabilities, not possible with turbine or reciprocating engines; including high reliability and efficiency, low engine weight and maintenance, low cooling drag and volume required, very low noise and vibration, and zero emissions. The only penalizing characteristic of electric propulsion is the current energy storage technology level, which is set to triple over the next 5-10 years through huge new investments in this field. Most importantly, electric propulsion offers incredible new degrees of freedom in aircraft system integration to achieve unprecedented levels of aerodynamic, propulsive, control, and structural synergistic coupling. A unique characteristic of electric propulsion is that the technology is nearly scale-free, permitting small motors to be parallelized for fail-safe redundancy, or distributed across the airframe for tightly coupled interdisciplinary functionality without significant impacts in motor-controller efficiency or specific weight. Maximizing the potential benefit of electric propulsion is dependent on applying this technology to synergistic mission concepts. The vehicle missions with the most benefit include those which constrain environmental impact (or limit noise, exhaust, or emission signatures) are short range, or where large differences exist in the propulsion system sizing between takeoff and cruise conditions. Electric propulsion offers the following unique capabilities that other propulsion systems can t provide for short range Vertical Takeoff and Landing (VTOL) aircraft; elimination of engine noise and emissions, drastic reduction in engine cooling and radiated heat, drastic reduction in vehicle vibration levels, drastic improvement in reliability and operating costs, variable speed output at full power, for improved cruise efficiency at low tip-speed, elimination of high/hot sizing penalty, and reduction of engine-out penalties.

Differential Multiscale Modeling of Chemically Complex Materials under Heavy Deformation: Biological, Bioinspired and Synthetic Hierarchical Materials

DTIC Science & Technology

2010-06-01

Buehler, “Meso- Origami : Folding Multilayer Graphene Sheets”, Applied Physics Letters, Vol. 95, paper #: 123121, 2009 D. Sen and M.J. Buehler, “Size and... geometry effects on flow stress in bioinspired de novo metal-matrix nanocomposites”, Advanced Engineering Materials, Vol. 11(10), pp. 774-781, 2009...behavior is recovered. Second, a subset of all geometries shows the inverse banana curve behavior. Interestingly, only 2% of all structures give the

Effects of Gas Turbine Component Performance on Engine and Rotary Wing Vehicle Size and Performance

NASA Technical Reports Server (NTRS)

Snyder, Christopher A.; Thurman, Douglas R.

2010-01-01

In support of the Fundamental Aeronautics Program, Subsonic Rotary Wing Project, further gas turbine engine studies have been performed to quantify the effects of advanced gas turbine technologies on engine weight and fuel efficiency and the subsequent effects on a civilian rotary wing vehicle size and mission fuel. The Large Civil Tiltrotor (LCTR) vehicle and mission and a previous gas turbine engine study will be discussed as a starting point for this effort. Methodology used to assess effects of different compressor and turbine component performance on engine size, weight and fuel efficiency will be presented. A process to relate engine performance to overall LCTR vehicle size and fuel use will also be given. Technology assumptions and levels of performance used in this analysis for the compressor and turbine components performances will be discussed. Optimum cycles (in terms of power specific fuel consumption) will be determined with subsequent engine weight analysis. The combination of engine weight and specific fuel consumption will be used to estimate their effect on the overall LCTR vehicle size and mission fuel usage. All results will be summarized to help suggest which component performance areas have the most effect on the overall mission.

Sediment transport modelling based on grain size trend analysis in Augusta Harbour (Sicily)

NASA Astrophysics Data System (ADS)

Barbera, Giuseppe; Feo, Roberto; Freni, Gabriele

2015-12-01

To support marine civil engineer in pollutant studies, sediment management or dredging operations, is useful to know how the sediments move in accumulation basin. This paper investigates the dynamic of the sediment path using a two-dimensional numeric model: the Grain Size Trend Analysis (GSTA). The GSTA was applied using GiSedTrend plugin, under GIS software. The case study is the Augusta Harbour, which is one of the most polluted Italian harbours. It is the marine part of the Site of National Interest (SNI) of Priolo Gargallo (Siracusa, Italy) and it can be hydrodynamically considered as a lagoon. Two scenarios were obtained by using different geostatistical criteria.

Tissue-engineered bone constructed in a bioreactor for repairing critical-sized bone defects in sheep.

PubMed

Li, Deqiang; Li, Ming; Liu, Peilai; Zhang, Yuankai; Lu, Jianxi; Li, Jianmin

2014-11-01

Repair of bone defects, particularly critical-sized bone defects, is a considerable challenge in orthopaedics. Tissue-engineered bones provide an effective approach. However, previous studies mainly focused on the repair of bone defects in small animals. For better clinical application, repairing critical-sized bone defects in large animals must be studied. This study investigated the effect of a tissue-engineered bone for repairing critical-sized bone defect in sheep. A tissue-engineered bone was constructed by culturing bone marrow mesenchymal-stem-cell-derived osteoblast cells seeded in a porous β-tricalcium phosphate ceramic (β-TCP) scaffold in a perfusion bioreactor. A critical-sized bone defect in sheep was repaired with the tissue-engineered bone. At the eighth and 16th week after the implantation of the tissue-engineered bone, X-ray examination and histological analysis were performed to evaluate the defect. The bone defect with only the β-TCP scaffold served as the control. X-ray showed that the bone defect was successfully repaired 16 weeks after implantation of the tissue-engineered bone; histological sections showed that a sufficient volume of new bones formed in β-TCP 16 weeks after implantation. Eight and 16 weeks after implantation, the volume of new bones that formed in the tissue-engineered bone group was more than that in the β-TCP scaffold group (P < 0.05). Tissue-engineered bone improved osteogenesis in vivo and enhanced the ability to repair critical-sized bone defects in large animals.

An Automated Pipeline for Engineering Many-Enzyme Pathways: Computational Sequence Design, Pathway Expression-Flux Mapping, and Scalable Pathway Optimization.

PubMed

Halper, Sean M; Cetnar, Daniel P; Salis, Howard M

2018-01-01

Engineering many-enzyme metabolic pathways suffers from the design curse of dimensionality. There are an astronomical number of synonymous DNA sequence choices, though relatively few will express an evolutionary robust, maximally productive pathway without metabolic bottlenecks. To solve this challenge, we have developed an integrated, automated computational-experimental pipeline that identifies a pathway's optimal DNA sequence without high-throughput screening or many cycles of design-build-test. The first step applies our Operon Calculator algorithm to design a host-specific evolutionary robust bacterial operon sequence with maximally tunable enzyme expression levels. The second step applies our RBS Library Calculator algorithm to systematically vary enzyme expression levels with the smallest-sized library. After characterizing a small number of constructed pathway variants, measurements are supplied to our Pathway Map Calculator algorithm, which then parameterizes a kinetic metabolic model that ultimately predicts the pathway's optimal enzyme expression levels and DNA sequences. Altogether, our algorithms provide the ability to efficiently map the pathway's sequence-expression-activity space and predict DNA sequences with desired metabolic fluxes. Here, we provide a step-by-step guide to applying the Pathway Optimization Pipeline on a desired multi-enzyme pathway in a bacterial host.

Role of Physicochemical Properties in Nanoparticle Toxicity

PubMed Central

Shin, Seung Won; Song, In Hyun; Um, Soong Ho

2015-01-01

With the recent rapid growth of technological comprehension in nanoscience, researchers have aimed to adapt this knowledge to various research fields within engineering and applied science. Dramatic advances in nanomaterials marked a new epoch in biomedical engineering with the expectation that they would have huge contributions to healthcare. However, several questions regarding their safety and toxicity have arisen due to numerous novel properties. Here, recent studies of nanomaterial toxicology will be reviewed from several physiochemical perspectives. A variety of physiochemical properties such as size distribution, electrostatics, surface area, general morphology and aggregation may significantly affect physiological interactions between nanomaterials and target biological areas. Accordingly, it is very important to finely tune these properties in order to safely fulfill a bio-user’s purpose. PMID:28347068

Management and systems engineering of the Kepler mission

NASA Astrophysics Data System (ADS)

Fanson, James; Livesay, Leslie; Frerking, Margaret; Cooke, Brian

2010-07-01

Kepler is the National Aeronautics and Space Administration's (NASA's) first mission capable of detecting Earth-size planets orbiting in the habitable zones around stars other than the sun. Selected for implementation in 2001 and launched in 2009, Kepler seeks to determine whether Earth-like planets are common or rare in the galaxy. The investigation requires a large, space-based photometer capable of simultaneously measuring the brightnesses of 100,000 stars at partper- million level of precision. This paper traces the development of the mission from the perspective of project management and systems engineering and describes various methodologies and tools that were found to be effective. The experience of the Kepler development is used to illuminate lessons that can be applied to future missions.

Management and Systems Engineering of the Kepler Mission

NASA Technical Reports Server (NTRS)

Fanson, James; Livesay, Leslie; Frerking, Margaret; Cooke, Brian

2010-01-01

Kepler is the National Aeronautics and Space Administration's (NASA's) first mission capable of detecting Earth-size planets orbiting in the habitable zones around stars other than the sun. Selected for implementation in 2001 and launched in 2009, Kepler seeks to determine whether Earth-like planets are common or rare in the galaxy. The investigation requires a large, space-based photometer capable of simultaneously measuring the brightnesses of 100,000 stars at part-per-million level of precision. This paper traces the development of the mission from the perspective of project management and systems engineering and describes various methodologies and tools that were found to be effective. The experience of the Kepler development is used to illuminate lessons that can be applied to future missions.

Ignition Study on a Rotary-valved Air-breathing Pulse Detonation Engine

NASA Astrophysics Data System (ADS)

Wu, Yuwen; Han, Qixiang; Shen, Yujia; Zhao, Wei

2017-05-01

In the present study, the ignition effect on detonation initiation was investigated in the air-breathing pulse detonation engine. Two kinds of fuel injection and ignition methods were applied. For one method, fuel and air was pre-mixed outside the PDE and then injected into the detonation tube. The droplet sizes of mixtures were measured. An annular cavity was used as the ignition section. For the other method, fuel-air mixtures were mixed inside the PDE, and a pre-combustor was utilized as the ignition source. At firing frequency of 20 Hz, transition to detonation was obtained. Experimental results indicated that the ignition position and initial flame acceleration had important effects on the deflagration-to-detonation transition.

Multimodal and synthetic aperture approach to full-field 3D shape and displacement measurements

NASA Astrophysics Data System (ADS)

Kujawińska, M.; Sitnik, R.

2017-08-01

Recently most of the measurement tasks in industry, civil engineering and culture heritage applications require archiving, characterization and monitoring of 3D objects and structures and their performance under changing conditions. These requirements can be met if multimodal measurement (MM) strategy is applied. It rely on effective combining structured light method and 3D digital image correlation with laser scanning/ToF, thermal imaging, multispectral imaging and BDRF measurements. In the case of big size and/or complicated objects MM have to be combined with hierarchical or synthetic aperture (SA) measurements. The new solutions in MM and SA strategies are presented and their applicability is shown at interesting cultural heritage and civil engineering applications.

High-fidelity simulations of a standing-wave thermoacoustic-piezoelectric engine

NASA Astrophysics Data System (ADS)

Lin, Jeffrey; Scalo, Carlo; Hesselink, Lambertus

2014-11-01

We have carried out time-domain three-dimensional and one-dimensional numerical simulations of a thermoacoustic Stirling heat engine (TASHE). The TASHE model adopted for our study is that of a standing-wave engine: a thermal gradient is imposed in a resonator tube and is capped with a piezoelectric diaphragm in a Helmholtz resonator cavity for acoustic energy extraction. The 0.51 m engine sustains 500 Pa pressure oscillations with atmospheric air and pressure. Such an engine is interesting in practice as an external heat engine with no mechanically-moving parts. Our numerical setup allows for both the evaluation of the nonlinear effects of scaling and the effect of a fully electromechanically-coupled impedance boundary condition, representative of a piezoelectric element. The thermoacoustic stack is fully resolved. Previous modeling efforts have focused on steady-state solvers with impedances or nonlinear effects without energy extraction. Optimization of scaling and the impedance for power output can now be simultaneously applied; engines of smaller sizes and higher frequencies suitable for piezoelectric energy extraction can be studied with three-dimensional solvers without restriction. Results at a low-amplitude regime were validated against results obtained from the steady-state solver DeltaEC and from experimental results in literature. Pressure and velocity amplitudes within the cavities match within 2% difference.

Larger ATV engine size correlates with an increased rate of traumatic brain injury.

PubMed

Butts, C Caleb; Rostas, Jack W; Lee, Y L; Gonzalez, Richard P; Brevard, Sidney B; Frotan, M Amin; Ahmed, Naveed; Simmons, Jon D

2015-04-01

Since the introduction of all-terrain vehicles (ATV) to the United States in 1971, injuries and mortalities related to their use have increased significantly. Furthermore, these vehicles have become larger and more powerful. As there are no helmet requirements or limitations on engine-size in the State of Alabama, we hypothesised that larger engine size would correlate with an increased incidence of traumatic brain injury (TBI) in patients following an ATV crash. Patient and ATV data were prospectively collected on all ATV crashes presenting to a level one trauma centre from September 2010 to May 2013. Collected data included: demographics, age of driver, ATV engine size, presence of helmet, injuries, and outcomes. The data were grouped according to the ATV engine size in cubic centimetres (cc). For the purposes of this study, TBI was defined as any type of intracranial haemorrhage on the initial computed tomography scan. There were 61 patients identified during the study period. Two patients (3%) were wearing a helmet at the time of injury. Patients on an ATV with an engine size of 350 cc or greater had higher Injury Severity Scores (13.9 vs. 7.5, p ≤ 0.05) and an increased incidence of TBI (26% vs. 0%, p ≤ 0.05) when compared to patients on ATV's with an engine size less than 350 cc. Patients on an ATV with an engine size of 350 cc or greater were more likely to have a TBI. The use of a helmet was rarely present in this cohort. Legislative efforts to implement rider protection laws for ATVs are warranted. Copyright © 2014 Elsevier Ltd. All rights reserved.

Teaching medical management and operations engineering for systems-based practice to radiology residents.

PubMed

Brandon, Catherine J; Mullan, Patricia B

2013-03-01

To better prepare radiology residents for providing care within the context of the larger health care system, this study evaluated the feasibility and impact of a curriculum to enhance radiology residents' understanding and ability to apply concepts from medical management and industrial and operational engineering to systems-based practice problems in radiology practice. A multiprofessional team including radiology, medical education, and industrial and operational engineering professionals collaborated in developing a seven-module curriculum, including didactic lectures, interactive large-group analysis, and small-group discussions with case-based radiology examples, which illustrated real-life management issues and the roles physicians held. Residents and faculty participated in topic selection. Pre- and post-instruction formative assessments were administered, and results were shared with residents during teaching sessions. Attendance and participation in case-based scenario resolutions indicate the feasibility and impact of the interactive curriculum on residents' interest and ability to apply curricular concepts to systems-based practice in radiology. Paired t test analyses (P < .05) and effect sizes showed residents significantly increased their knowledge and ability to apply concepts to systems-based practice issues in radiology. Our iterative curriculum development and implementation process demonstrated need and support for a multiprofessional team approach to teach management and operational engineering concepts. Curriculum topics are congruent with Accreditation Council for Graduate Medical Education requirements for systems-based practice. The case-based curriculum using a mixed educational format of didactic lectures and small-group discussion and problem analysis could be adopted for other radiology programs, for both residents and continuing medical education applications. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

Fuel-injector/air-swirl characterization

NASA Technical Reports Server (NTRS)

Mcvey, J. B.; Kennedy, J. B.; Russell, S.

1988-01-01

Experimental data on the characteristics of the spray produced by a gas-turbine engine airblast fuel injector are reported. The data acquired include the mass-flux distribution measured by use of a high-resolution spray patternator; the gas-phase velocity field measured by use of a two-component laser Doppler velocimeter, and the liquid droplet size and velocity distributions measured by use of a single-component phase-Doppler anemometer. The data are intended for use in assessments of two-phase flow computational methods as applied to combustor design procedures.

Aeronautical Situational Awareness - Airport Surface

NASA Technical Reports Server (NTRS)

Linetsky, Vladimir M.; Ivancic, William D.; Vaden, Karl R.

2017-01-01

This paper advocates for a specific design approach, based on simple principals, yet addresses challenges faced by the system engineers when designing complex data and information infrastructure. The document provides guidance for breaking out various work elements in the overall network architecture design, so that communication systems are conceived and effectively realized regardless of their location, size and local specifics. Although targeted at the Global Airspace System (GAS) and National Airspace System (NAS), this framework can be applied to any network-centric architecture.

Error-Tolerant Quasi-Paraboloidal Solar Concentrator

NASA Technical Reports Server (NTRS)

Wagner, Howard A.

1988-01-01

Scalloping reflector surface reduces sensitivity to manufacturing and aiming errors. Contrary to intuition, most effective shape of concentrating reflector for solar heat engine is not perfect paraboloid. According to design studies for Space Station solar concentrator, scalloped, nonimaging approximation to perfect paraboloid offers better overall performance in view of finite apparent size of Sun, imperfections of real equipment, and cost of accommodating these complexities. Scalloped-reflector concept also applied to improve performance while reducing cost of manufacturing and operation of terrestrial solar concentrator.

Morphological characterization of diesel soot agglomerates based on the Beer-Lambert law

NASA Astrophysics Data System (ADS)

Lapuerta, Magín; Martos, Francisco J.; José Expósito, Juan

2013-03-01

A new method is proposed for the determination of the number of primary particles composing soot agglomerates emitted from diesel engines as well as their individual fractal dimension. The method is based on the Beer-Lambert law and it is applied to micro-photographs taken in high resolution transmission electron microscopy. Differences in the grey levels of the images lead to a more accurate estimation of the geometry of the agglomerate (in this case radius of gyration) than other methods based exclusively on the planar projections of the agglomerates. The method was validated by applying it to different images of the same agglomerate observed from different angles of incidence, and proving that the effect of the angle of incidence is minor, contrary to other methods. Finally, the comparisons with other methods showed that the size, number of primary particles and fractal dimension (the latter depending on the particle size) are usually underestimated when only planar projections of the agglomerates are considered.

Systems Engineering Processes Applied to Ground Vehicle Integration at US Army Tank Automotive Research, Development, and Engineering Center (TARDEC)

DTIC Science & Technology

2010-08-19

UNCLASSIFIED Systems Engineering Processes Applied To Ground Vehicle Integration at US Army Tank Automotive Research, Development, and Engineering...DATES COVERED - 4. TITLE AND SUBTITLE Systems Engineering Processes Applied To Ground Vehicle Integration at US Army Tank Automotive Research...release, distribution unlimited 13. SUPPLEMENTARY NOTES Presented at NDIAs Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), 17 22

Yield Asymmetry Design of Magnesium Alloys by Integrated Computational Materials Engineering

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

Li, Dongsheng; Joshi, Vineet V.; Lavender, Curt A.

2013-11-01

Deformation asymmetry of magnesium alloys is an important factor on machine design in automobile industry. Represented by the ratio of compressive yield stress (CYS) against tensile yield stress (TYS), deformation asymmetry is strongly related to microstructure, characterized by texture and grain size. Modified intermediate phi-model, a polycrystalline viscoplasticity model, is used to predict the deformation behavior of magnesium alloys with different grain sizes. Validated with experimental results, integrated computational materials engineering is applied to find out the route in achieving desired asymmetry by thermomechanical processing. In some texture, for example, rolled texture, CYS/TYS is smaller than 1 under different loadingmore » directions. In some texture, for example, extruded texture, asymmetry is large along normal direction. Starting from rolled texture, the asymmetry will increased to close to 1 along rolling direction after compressed to a strain of 0.2. Our model shows that grain refinement increases CYS/TYS. Besides texture control, grain refinement can also optimize the yield asymmetry. After the grain size decreased to a critical value, CYS/TYS reaches to 1 since CYS increases much faster than TYS. By tailoring the microstructure using texture control and grain refinement, it is achievable to optimize yield asymmetry in wrought magnesium alloys.« less

Yield asymmetry design of magnesium alloys by integrated computational materials engineering

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

Li, Dongsheng; Joshi, Vineet; Lavender, Curt

2013-11-01

Deformation asymmetry of magnesium alloys is an important factor on machine design in the automobile industry. Represented by the ratio of compressive yield stress (CYS) against tensile yield stress (TYS), deformation asymmetry is strongly related to texture and grain size. A polycrystalline viscoplasticity model, modified intermediate Φ-model, is used to predict the deformation behavior of magnesium alloys with different grain sizes. Validated with experimental results, integrated computational materials engineering is applied to find out the route in achieving desired asymmetry via thermomechanical processing. For example, CYS/TYS in rolled texture is smaller than 1 under different loading directions. In other textures,more » such as extruded texture, CYS/TYS is large along the normal direction. Starting from rolled texture, asymmetry will increase to close to 1 along the rolling direction after being compressed to a strain of 0.2. Our modified Φ-model also shows that grain refinement increases CYS/TYS. Along with texture control, grain refinement also can optimize the yield asymmetry. After the grain size decreases to a critical value, CYS/TYS reaches to 1 because CYS increases much faster than TYS. By tailoring the microstructure using texture control and grain refinement, it is achievable to optimize yield asymmetry in wrought magnesium alloys.« less

A conceptual study of the potential for automotive-derived and free-piston Stirling engines in 30- to 400-kilowatt stationary power applications

NASA Technical Reports Server (NTRS)

Vatsky, A.; Chen, H. S.; Dineen, J.

1982-01-01

The technical feasibility of applying automotive-derived kinematic and free-piston Stirling engine concepts for stationary applications was explored. Automotive-derived engines offer cost advantages by providing a mature and developd engine technology base with downrating and parts commonality options for specific applications. Two engine sizes (30 and 400 kW), two Stirling engine configurations (kinematic and free-piston), and two output systems (crankshaft and hydraulic pump) were studied. The study includes the influences of using either hydrogen or helium as the working gas. The first kinematic configuration selects an existing Stirling engine design from an automotive application and adapts it to stationary requirements. A 50,000-hour life requirement was established by downrating the engine to 40 kW and reducing auxiliary loads. Efficiency improvements were gained by selective material and geometric variations and peak brake efficiency of 36.8 percent using helium gas was achieved. The second design was a four-cylinder, 400 kW engine, utilizing a new output drive system known as the z-crank, which provides lower friction losses and variable stroke power control. Three different material and working gas combinations were considered. Brake efficiency levels varied from 40.5 percent to 45.6 percent. A 37.5 kW single-cycle, free-piston hydraulic output design was generated by scaling one cylinder of the original automotive engine and mating it to a counterbalanced reciprocal hydraulic pump. Metallic diaphragms were utilized to transmit power.

A conceptual study of the potential for automotive-derived and free-piston Stirling engines in 30- to 400-kilowatt stationary power applications

NASA Astrophysics Data System (ADS)

Vatsky, A.; Chen, H. S.; Dineen, J.

1982-05-01

The technical feasibility of applying automotive-derived kinematic and free-piston Stirling engine concepts for stationary applications was explored. Automotive-derived engines offer cost advantages by providing a mature and developd engine technology base with downrating and parts commonality options for specific applications. Two engine sizes (30 and 400 kW), two Stirling engine configurations (kinematic and free-piston), and two output systems (crankshaft and hydraulic pump) were studied. The study includes the influences of using either hydrogen or helium as the working gas. The first kinematic configuration selects an existing Stirling engine design from an automotive application and adapts it to stationary requirements. A 50,000-hour life requirement was established by downrating the engine to 40 kW and reducing auxiliary loads. Efficiency improvements were gained by selective material and geometric variations and peak brake efficiency of 36.8 percent using helium gas was achieved. The second design was a four-cylinder, 400 kW engine, utilizing a new output drive system known as the z-crank, which provides lower friction losses and variable stroke power control. Three different material and working gas combinations were considered. Brake efficiency levels varied from 40.5 percent to 45.6 percent. A 37.5 kW single-cycle, free-piston hydraulic output design was generated by scaling one cylinder of the original automotive engine and mating it to a counterbalanced reciprocal hydraulic pump. Metallic diaphragms were utilized to transmit power.

A model describing intra-granular fission gas behaviour in oxide fuel for advanced engineering tools

NASA Astrophysics Data System (ADS)

Pizzocri, D.; Pastore, G.; Barani, T.; Magni, A.; Luzzi, L.; Van Uffelen, P.; Pitts, S. A.; Alfonsi, A.; Hales, J. D.

2018-04-01

The description of intra-granular fission gas behaviour is a fundamental part of any model for the prediction of fission gas release and swelling in nuclear fuel. In this work we present a model describing the evolution of intra-granular fission gas bubbles in terms of bubble number density and average size, coupled to gas release to grain boundaries. The model considers the fundamental processes of single gas atom diffusion, gas bubble nucleation, re-solution and gas atom trapping at bubbles. The model is derived from a detailed cluster dynamics formulation, yet it consists of only three differential equations in its final form; hence, it can be efficiently applied in engineering fuel performance codes while retaining a physical basis. We discuss improvements relative to previous single-size models for intra-granular bubble evolution. We validate the model against experimental data, both in terms of bubble number density and average bubble radius. Lastly, we perform an uncertainty and sensitivity analysis by propagating the uncertainties in the parameters to model results.

Wavelength Independent Optical Lithography and Microscopy

DTIC Science & Technology

1990-10-30

Engineering Physics H. Barshatzky (1985 - present) Cornell, School of Applied & Engineering Physics I. Walton (1987 - 1988) National Semiconductor...Santa Clara, California R. Chen (1989 - 1990) Digital Equipment Corporation S. Boedecker (1990 - present) Cornell, School of Applied & Engineering Physics...H. Chen (1990 - present) Cornell, Department of Materials Science and Engineering M. Park (1987) Cornell, School of Applied & Engineering Physics M. Tornai (1988) UCLA, Dept. Medical Physics,

Challenges for Engineering Design, Construction, and Maintenance of Infrastructure in Afghanistan

DTIC Science & Technology

2010-11-01

applied engineering expertise that collectively can solve challenging infra- structure problems. USACE-ERDC’s researchers and engineers are field...Development Center (ERDC) possesses a unique combination of basic research and applied engineering expertise that collectively can solve challenging...restoration, and other projects. The USACE Engineer Research and Development Center (ERDC) possesses a unique combination of basic research and applied

Estimating search engine index size variability: a 9-year longitudinal study.

PubMed

van den Bosch, Antal; Bogers, Toine; de Kunder, Maurice

One of the determining factors of the quality of Web search engines is the size of their index. In addition to its influence on search result quality, the size of the indexed Web can also tell us something about which parts of the WWW are directly accessible to the everyday user. We propose a novel method of estimating the size of a Web search engine's index by extrapolating from document frequencies of words observed in a large static corpus of Web pages. In addition, we provide a unique longitudinal perspective on the size of Google and Bing's indices over a nine-year period, from March 2006 until January 2015. We find that index size estimates of these two search engines tend to vary dramatically over time, with Google generally possessing a larger index than Bing. This result raises doubts about the reliability of previous one-off estimates of the size of the indexed Web. We find that much, if not all of this variability can be explained by changes in the indexing and ranking infrastructure of Google and Bing. This casts further doubt on whether Web search engines can be used reliably for cross-sectional webometric studies.

Resource Isolation Method for Program’S Performance on CMP

NASA Astrophysics Data System (ADS)

Guan, Ti; Liu, Chunxiu; Xu, Zheng; Li, Huicong; Ma, Qiang

2017-10-01

Data center and cloud computing are more popular, which make more benefits for customers and the providers. However, in data center or clusters, commonly there is more than one program running on one server, but programs may interference with each other. The interference may take a little effect, however, the interference may cause serious drop down of performance. In order to avoid the performance interference problem, the mechanism of isolate resource for different programs is a better choice. In this paper we propose a light cost resource isolation method to improve program’s performance. This method uses Cgroups to set the dedicated CPU and memory resource for a program, aiming at to guarantee the program’s performance. There are three engines to realize this method: Program Monitor Engine top program’s resource usage of CPU and memory and transfer the information to Resource Assignment Engine; Resource Assignment Engine calculates the size of CPU and memory resource should be applied for the program; Cgroups Control Engine divide resource by Linux tool Cgroups, and drag program in control group for execution. The experiment result show that making use of the resource isolation method proposed by our paper, program’s performance can be improved.

From stem to roots: Tissue engineering in endodontics

PubMed Central

Kala, M.; Banthia, Priyank; Banthia, Ruchi

2012-01-01

The vitality of dentin-pulp complex is fundamental to the life of tooth and is a priority for targeting clinical management strategies. Loss of the tooth, jawbone or both, due to periodontal disease, dental caries, trauma or some genetic disorders, affects not only basic mouth functions but aesthetic appearance and quality of life. One novel approach to restore tooth structure is based on biology: regenerative endodontic procedure by application of tissue engineering. Regenerative endodontics is an exciting new concept that seeks to apply the advances in tissue engineering to the regeneration of the pulp-dentin complex. The basic logic behind this approach is that patient-specific tissue-derived cell populations can be used to functionally replace integral tooth tissues. The development of such ‘test tube teeth’ requires precise regulation of the regenerative events in order to achieve proper tooth size and shape, as well as the development of new technologies to facilitate these processes. This article provides an extensive review of literature on the concept of tissue engineering and its application in endodontics, providing an insight into the new developmental approaches on the horizon. Key words:Regenerative, tissue engineering, stem cells, scaffold. PMID:24558528

Analysis of Turbofan Design Options for an Advanced Single-Aisle Transport Aircraft

NASA Technical Reports Server (NTRS)

Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael T.; Thurman, Douglas R.

2009-01-01

The desire for higher engine efficiency has resulted in the evolution of aircraft gas turbine engines from turbojets, to low bypass ratio, first generation turbofans, to today's high bypass ratio turbofans. It is possible that future designs will continue this trend, leading to very-high or ultra-high bypass ratio (UHB) engines. Although increased bypass ratio has clear benefits in terms of propulsion system metrics such as specific fuel consumption, these benefits may not translate into aircraft system level benefits due to integration penalties. In this study, the design trade space for advanced turbofan engines applied to a single-aisle transport (737/A320 class aircraft) is explored. The benefits of increased bypass ratio and associated enabling technologies such as geared fan drive are found to depend on the primary metrics of interest. For example, bypass ratios at which fuel consumption is minimized may not require geared fan technology. However, geared fan drive does enable higher bypass ratio designs which result in lower noise. Regardless of the engine architecture chosen, the results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.

Performance of a Line Loss Correction Method for Gas Turbine Emission Measurements

NASA Astrophysics Data System (ADS)

Hagen, D. E.; Whitefield, P. D.; Lobo, P.

2015-12-01

International concern for the environmental impact of jet engine exhaust emissions in the atmosphere has led to increased attention on gas turbine engine emission testing. The Society of Automotive Engineers Aircraft Exhaust Emissions Measurement Committee (E-31) has published an Aerospace Information Report (AIR) 6241 detailing the sampling system for the measurement of non-volatile particulate matter from aircraft engines, and is developing an Aerospace Recommended Practice (ARP) for methodology and system specification. The Missouri University of Science and Technology (MST) Center for Excellence for Aerospace Particulate Emissions Reduction Research has led numerous jet engine exhaust sampling campaigns to characterize emissions at different locations in the expanding exhaust plume. Particle loss, due to various mechanisms, occurs in the sampling train that transports the exhaust sample from the engine exit plane to the measurement instruments. To account for the losses, both the size dependent penetration functions and the size distribution of the emitted particles need to be known. However in the proposed ARP, particle number and mass are measured, but size is not. Here we present a methodology to generate number and mass correction factors for line loss, without using direct size measurement. A lognormal size distribution is used to represent the exhaust aerosol at the engine exit plane and is defined by the measured number and mass at the downstream end of the sample train. The performance of this line loss correction is compared to corrections based on direct size measurements using data taken by MST during numerous engine test campaigns. The experimental uncertainty in these correction factors is estimated. Average differences between the line loss correction method and size based corrections are found to be on the order of 10% for number and 2.5% for mass.

Engine Concept Study for an Advanced Single-Aisle Transport

NASA Technical Reports Server (NTRS)

Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael; Thurman, Douglas R.

2009-01-01

The desire for higher engine efficiency has resulted in the evolution of aircraft gas turbine engines from turbojets, to low bypass ratio, first generation turbofans, to today's high bypass ratio turbofans. Although increased bypass ratio has clear benefits in terms of propulsion system metrics such as specific fuel consumption, these benefits may not translate into aircraft system level benefits due to integration penalties. In this study, the design trade space for advanced turbofan engines applied to a single aisle transport (737/A320 class aircraft) is explored. The benefits of increased bypass ratio and associated enabling technologies such as geared fan drive are found to depend on the primary metrics of interest. For example, bypass ratios at which mission fuel consumption is minimized may not require geared fan technology. However, geared fan drive does enable higher bypass ratio designs which result in lower noise. The results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.

Trial of Engineer Educating of Manufacturing Field in Kagoshima National College of Technology

NASA Astrophysics Data System (ADS)

Nakamura, Itaru; Hombu, Mitsuyuki; Kusuhara, Yoshito; Kashine, Kenji; Sakasegawa, Eiichi; Tashima, Daisuke; Fukidome, Hiromi

In Kagoshima National College of Technology, based on investigation with “the job boost measure investigation work in a power supply area” undertaken in the 2005 fiscal year, we accepted the trust from Kyushu Bureau of Economy, Trade and Industry, and undertook “the small-and-medium-sized-enterprises personnel educating work which utilized the technical college etc.” for three years from the 2006 fiscal year to the 2008 fiscal year. As the trial of engineer educating according to the electrical engineering concept to the manufacturing field based on a conventional result, we act as a professor of the base technique for applying alternative energy (a fuel cell and a solar cell) in which social needs are powerful these days, and aim at aiming at cultivation of the problem-solving type engineer who can contribute to a low carbon society through manufacturing, we undertook this work according to the manufacturing bearer educating work (personnel educating and secured work of the manufacturing field) in the 2009 fiscal year of National Federation of Small Business Associations.

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.

40 CFR 1039.640 - What special provisions apply to branded engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What special provisions apply to branded engines? 1039.640 Section 1039.640 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... ENGINES Special Compliance Provisions § 1039.640 What special provisions apply to branded engines? The...

78 FR 77334 - Small Business Size Standards: Construction

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-23

... Dredging and Surface Cleanup Activities, an ``exception'' under Other Heavy and Civil Engineering... ``exception'' under Other Heavy and Civil Engineering Construction (NAICS 238910), from $20 million to $30... exception under Other Heavy and Civil Engineering Construction (NAICS 238910) and retain the current size...

An optical method for measuring exhaust gas pressure from an internal combustion engine at high speed

NASA Astrophysics Data System (ADS)

Leach, Felix C. P.; Davy, Martin H.; Siskin, Dmitrij; Pechstedt, Ralf; Richardson, David

2017-12-01

Measurement of exhaust gas pressure at high speed in an engine is important for engine efficiency, computational fluid dynamics analysis, and turbocharger matching. Currently used piezoresistive sensors are bulky, require cooling, and have limited lifetimes. A new sensor system uses an interferometric technique to measure pressure by measuring the size of an optical cavity, which varies with pressure due to movement of a diaphragm. This pressure measurement system has been used in gas turbine engines where the temperatures and pressures have no significant transients but has never been applied to an internal combustion engine before, an environment where both temperature and pressure can change rapidly. This sensor has been compared with a piezoresistive sensor representing the current state-of-the-art at three engine operating points corresponding to both light load and full load. The results show that the new sensor can match the measurements from the piezoresistive sensor except when there are fast temperature swings, so the latter part of the pressure during exhaust blowdown is only tracked with an offset. A modified sensor designed to compensate for these temperature effects is also tested. The new sensor has shown significant potential as a compact, durable sensor, which does not require external cooling.

An optical method for measuring exhaust gas pressure from an internal combustion engine at high speed.

PubMed

Leach, Felix C P; Davy, Martin H; Siskin, Dmitrij; Pechstedt, Ralf; Richardson, David

2017-12-01

Measurement of exhaust gas pressure at high speed in an engine is important for engine efficiency, computational fluid dynamics analysis, and turbocharger matching. Currently used piezoresistive sensors are bulky, require cooling, and have limited lifetimes. A new sensor system uses an interferometric technique to measure pressure by measuring the size of an optical cavity, which varies with pressure due to movement of a diaphragm. This pressure measurement system has been used in gas turbine engines where the temperatures and pressures have no significant transients but has never been applied to an internal combustion engine before, an environment where both temperature and pressure can change rapidly. This sensor has been compared with a piezoresistive sensor representing the current state-of-the-art at three engine operating points corresponding to both light load and full load. The results show that the new sensor can match the measurements from the piezoresistive sensor except when there are fast temperature swings, so the latter part of the pressure during exhaust blowdown is only tracked with an offset. A modified sensor designed to compensate for these temperature effects is also tested. The new sensor has shown significant potential as a compact, durable sensor, which does not require external cooling.

Fuzzy control based engine sizing optimization for a fuel cell/battery hybrid mini-bus

NASA Astrophysics Data System (ADS)

Kim, Minjin; Sohn, Young-Jun; Lee, Won-Yong; Kim, Chang-Soo

The fuel cell/battery hybrid vehicle has been focused for the alternative engine of the existing internal-combustion engine due to the following advantages of the fuel cell and the battery. Firstly, the fuel cell is highly efficient and eco-friendly. Secondly, the battery has the fast response for the changeable power demand. However, the competitive efficiency of the hybrid fuel cell vehicle is necessary to successfully alternate the conventional vehicles with the fuel cell hybrid vehicle. The most relevant factor which affects the overall efficiency of the hybrid fuel cell vehicle is the relative engine sizing between the fuel cell and the battery. Therefore the design method to optimize the engine sizing of the fuel cell hybrid vehicle has been proposed. The target system is the fuel cell/battery hybrid mini-bus and its power distribution is controlled based on the fuzzy logic. The optimal engine sizes are determined based on the simulator developed in this paper. The simulator includes the several models for the fuel cell, the battery, and the major balance of plants. After the engine sizing, the system efficiency and the stability of the power distribution are verified based on the well-known driving schedule. Consequently, the optimally designed mini-bus shows good performance.

40 CFR 1051.645 - What special provisions apply to branded engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What special provisions apply to branded engines? 1051.645 Section 1051.645 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions § 1051.645 What special provisions apply to branded engines? The following provisions apply if you...

A New 1000 F Magnetic Bearing Test Rig

NASA Technical Reports Server (NTRS)

Kascak, Albert F.; Montague, Gerald T.; Brown, Gerald V.; Palazzolo, Alan B.

1997-01-01

NASA and the Army are currently exploring the possibility of using magnetic bearings in gas turbine engines. The use of magnetic bearings in gas turbine engines could increase the reliability by eliminating the lubrication system. The use of magnetic bearings could also increase the speed and the size of the shafts in the engine, thus reducing vibrations and possibly eliminating third bearings. Magnetic bearings can apply forces to the shafts and move them so that blade tips and seals do not rub. This could be part of an active vibration cancellation system. Also, whirling (displacing the shaft center line) may delay rotating stall and increase the stall margin of the engine. Magnetic bearings coupled with an integral starter generator could result in a more efficient 'more electric' engine. The IHPTET program, a joint DOD-industry program, has identified a need for a high temperature, (as high as 1200 F), magnetic bearing that could be demonstrated in a phase m engine. A magnetic bearing is similar to an electric motor. The magnetic bearing has a laminated rotor and stator made out of cobalt steel. The stator has a series of coils of wire wound around it. These coils f u. a series of electromagnets around the circumference. These magnets exert a force on the rotor to keep the rotor in the center of the cavity. The centering force is commanded by a controller based on shaft position, (measured by displacement probes). The magnetic bearing can only pull and is basically unstable before active control is applied The engine shafts, bearings, and case form a flexible structure which contain a large number of modes. A controller is necessary to stabilize these modes. A power amplifier is also necessary to provide the current prescribed by the controller to the magnetic bearings. In case of very high loads, a conventional back up bearing will engage and stop the rotor and stator from rubbing.

Design and analysis of frequency-selective surface enabled microbolometers

NASA Astrophysics Data System (ADS)

Liu, Tao; Qu, Chuang; Almasri, Mahmoud; Kinzel, Edward

2016-05-01

Frequency Selective Surfaces (FSS) are periodic array of sub-wavelength antenna elements. They allow the absorptance and reflectance of a surface to be engineered with respect to wavelength, polarization and angle-of-incidence. This paper applies this technique to microbolometers for uncooled infrared sensing applications. Both narrowband and broadband near perfect absorbing surfaces are synthesized and applied engineer the response of microbolometers. The paper focuses on simple FSS geometries (hexagonal close packed disk arrays) that can be fabricated using conventional lithographic tools for use at thermal infrared wavelengths (feature sizes > 1 μm). The affects of geometry and material selection for this geometry is described in detail. In the microbolometer application, the FSS controls the absorption rather than a conventional Fabry-Perot cavity and this permits an improved thermal design. A coupled full wave electromagnetic/transient thermal model of the entire microbolometer is presented and analyzed using the finite element method. The absence of the cavity also permits more flexibility in the design of the support arms/contacts. This combined modeling permits prediction of the overall device sensitivity, time-constant and the specific detectivity.

Electrostatic Plasma Accelerator (EPA)

NASA Technical Reports Server (NTRS)

Brophy, John R.; Aston, Graeme

1989-01-01

The Electrostatic Plasma Accelerator (EPA) is a thruster concept which promises specific impulse levels between low power arcjets and those of the ion engine while retaining the relative simplicity of the arcjet. The EPA thruster produces thrust through the electrostatic acceleration of a moderately dense plasma. No accelerating electrodes are used and the specific impulse is a direct function of the applied discharge voltage and the propellant atomic mass. The goal of the present program is to demonstrate feasibility of the EPA thruster concept through experimental and theoretical investigations of the EPA acceleration mechanism and discharge chamber performance. Experimental investigations will include operating the test bed ion (TBI) engine as an EPA thruster and parametrically varying the thruster geometry and operating conditions to quantify the electrostatic plasma acceleration effect. The theoretical investigations will include the development of a discharge chamber model which describes the relationships between the engine size, plasma properties, and overall performance. For the EPA thruster to be a viable propulsion concept, overall thruster efficiencies approaching 30% with specific impulses approaching 1000 s must be achieved.

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

Michael Keane; Xiao-Chun Shi; Tong-man Ong

The project staff partnered with Costas Sioutas from the University of Southern California to apply the VACES (Versatile Aerosol Concentration Enhancement System) to a diesel engine test facility at West Virginia University Department of Mechanical Engineering and later the NIOSH Lake Lynn Mine facility. The VACES system was able to allow diesel exhaust particulate matter (DPM) to grow to sufficient particle size to be efficiently collected with the SKC Biosampler impinger device, directly into a suspension of simulated pulmonary surfactant. At the WVU-MAE facility, the concentration of the aerosol was too high to allow efficient use of the VACES concentrationmore » enhancement, although aerosol collection was successful. Collection at the LLL was excellent with the diluted exhaust stream. In excess of 50 samples were collected at the LLL facility, along with matching filter samples, at multiple engine speed and load conditions. Replicate samples were combined and concentration increased using a centrifugal concentrator. Bioassays were negative for all tested samples, but this is believed to be due to insufficient concentration in the final assay suspensions.« less

Implications of Requiring New Production of Older Aircraft Types (less than 75,000 pounds) to Meet Amended Noise Standards.

DTIC Science & Technology

1980-06-01

ratio CF700 engine, do not qualify, but in each case the producer has plans for, or is delivering a model using the TFE731 engine that does qualify. CF700...the size range, namely, the Learjets using the CJ610 engine and the Gulfstream 3 using the Spey. All medium-sized jets using the TFE731 are quieter...very few engines available for aircraft in each size range: the JT15 and CJ610 for small aircraft, the CF700, ATF3, and TFE731 for medium aircraft and

Study of advanced rotary combustion engines for commuter aircraft

NASA Technical Reports Server (NTRS)

Berkowitz, M.; Jones, C.; Myers, D.

1983-01-01

Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.

Update of GRASP/Ada reverse engineering tools for Ada

NASA Technical Reports Server (NTRS)

Cross, James H., II

1992-01-01

The GRASP/Ada project (Graphical Representations of Algorithms, Structures, and Processes for Ada) has successfully created and prototyped a new algorithmic level graphical representation of Ada software, the Control Structure Diagram (CSD). The primary impetus for creation of the CSD was to improve the comprehension efficiency of Ada software and, as a result, improve reliability and reduce costs. The emphasis was on the automatic generation of the CSD from Ada PDL or source code to support reverse engineering and maintenance. The CSD has the potential to replace traditional prettyprinted Ada source code. In Phase 1 of the GRASP/Ada project, the CSD graphical constructs were created and applied manually to several small Ada programs. A prototype (Version 1) was designed and implemented using FLEX and BISON running under VMS on a VAS 11-780. In Phase 2, the prototype was improved and ported to the Sun 4 platform under UNIX. A user interface was designed and partially implemented using the HP widget toolkit and the X Windows System. In Phase 3, the user interface was extensively reworked using the Athena widget toolkit and X Windows. The prototype was applied successfully to numerous Ada programs ranging in size from several hundred to several thousand lines of source code. Following Phase 3, the prototype was evaluated by software engineering students at Auburn University and then updated with significant enhancements to the user interface including editing capabilities. Version 3.2 of the prototype was prepared for limited distribution to facilitate further evaluation. The current prototype provides the capability for the user to generate CSD's from Ada PDL or source code in a reverse engineering as well as forward engineering mode with a level of flexibility suitable for practical application.

Characterization of infectious aerosols in health care facilities: an aid to effective engineering controls and preventive strategies.

PubMed

Cole, E C; Cook, C E

1998-08-01

Assessment of strategies for engineering controls for the prevention of airborne infectious disease transmission to patients and to health care and related workers requires consideration of the factors relevant to aerosol characterization. These factors include aerosol generation, particle size and concentrations, organism viability, infectivity and virulence, airflow and climate, and environmental sampling and analysis. The major focus on attention to engineering controls comes from recent increases in tuberculosis, particularly the multidrug-resistant varieties in the general hospital population, the severely immunocompromised, and those in at-risk and confined environments such as prisons, long-term care facilities, and shelters for the homeless. Many workers are in close contact with persons who have active, undiagnosed, or insufficiently treated tuberculosis. Additionally, patients and health care workers may be exposed to a variety of pathogenic human viruses, opportunistic fungi, and bacteria. This report therefore focuses on the nature of infectious aerosol transmission in an attempt to determine which factors can be systematically addressed to result in proven, applied engineering approaches to the control of infectious aerosols in hospital and health care facility environments. The infectious aerosols of consideration are those that are generated as particles of respirable size by both human and environmental sources and that have the capability of remaining viable and airborne for extended periods in the indoor environment. This definition precludes skin and mucous membrane exposures occurring from splashes (rather than true aerosols) of blood or body fluids containing infectious disease agents. There are no epidemiologic or laboratory studies documenting the transmission of bloodborne virus by way of aerosols.

A modular approach to creating large engineered cartilage surfaces.

PubMed

Ford, Audrey C; Chui, Wan Fung; Zeng, Anne Y; Nandy, Aditya; Liebenberg, Ellen; Carraro, Carlo; Kazakia, Galateia; Alliston, Tamara; O'Connell, Grace D

2018-01-23

Native articular cartilage has limited capacity to repair itself from focal defects or osteoarthritis. Tissue engineering has provided a promising biological treatment strategy that is currently being evaluated in clinical trials. However, current approaches in translating these techniques to developing large engineered tissues remains a significant challenge. In this study, we present a method for developing large-scale engineered cartilage surfaces through modular fabrication. Modular Engineered Tissue Surfaces (METS) uses the well-known, but largely under-utilized self-adhesion properties of de novo tissue to create large scaffolds with nutrient channels. Compressive mechanical properties were evaluated throughout METS specimens, and the tensile mechanical strength of the bonds between attached constructs was evaluated over time. Raman spectroscopy, biochemical assays, and histology were performed to investigate matrix distribution. Results showed that by Day 14, stable connections had formed between the constructs in the METS samples. By Day 21, bonds were robust enough to form a rigid sheet and continued to increase in size and strength over time. Compressive mechanical properties and glycosaminoglycan (GAG) content of METS and individual constructs increased significantly over time. The METS technique builds on established tissue engineering accomplishments of developing constructs with GAG composition and compressive properties approaching native cartilage. This study demonstrated that modular fabrication is a viable technique for creating large-scale engineered cartilage, which can be broadly applied to many tissue engineering applications and construct geometries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Digital Image Analysis Algorithm For Determination of Particle Size Distributions In Diesel Engines

NASA Astrophysics Data System (ADS)

Armas, O.; Ballesteros, R.; Gomez, A.

One of the most serious problems associated to Diesel engines is pollutant emissions, standing out nitrogen oxides and particulate matter. However, although current emis- sions standards in Europe and America with regard to light vehicles and heavy duty engines refer the particulate limit in mass units, concern for knowing size and number of particles emitted by engines is being increased recently. This interest is promoted by last studies about particle harmful effects on health and is enhanced by recent changes in internal combustion engines technology. This study is focused on the implementation of a method to determine the particle size distribution made up in current methodology for vehicles certification in Europe. It will use an automated Digital Image Analysis Algorithm (DIAA) to determine particle size trends from Scanning Electron Microscope (SEM) images of filters charged in a dilution system used for measuring specific particulate emissions. The experimental work was performed on a steady state direct injection Diesel en- gine with 0.5 MW rated power, being considered as a typical engine in middle power industries. Particulate size distributions obtained using DIAA and a Scanning Mobil- ity Particle Sizer (SMPS), nowadays considered as the most reliable technique, were compared. Although number concentration detected by this method does not repre- sent real flowing particle concentration, this algorithm fairly reproduces the trends observed with SMPS when the engine load is varied.

Comparison of two probability distributions used to model sizes of undiscovered oil and gas accumulations: Does the tail wag the assessment?

USGS Publications Warehouse

Attanasi, E.D.; Charpentier, R.R.

2002-01-01

Undiscovered oil and gas assessments are commonly reported as aggregate estimates of hydrocarbon volumes. Potential commercial value and discovery costs are, however, determined by accumulation size, so engineers, economists, decision makers, and sometimes policy analysts are most interested in projected discovery sizes. The lognormal and Pareto distributions have been used to model exploration target sizes. This note contrasts the outcomes of applying these alternative distributions to the play level assessments of the U.S. Geological Survey's 1995 National Oil and Gas Assessment. Using the same numbers of undiscovered accumulations and the same minimum, medium, and maximum size estimates, substitution of the shifted truncated lognormal distribution for the shifted truncated Pareto distribution reduced assessed undiscovered oil by 16% and gas by 15%. Nearly all of the volume differences resulted because the lognormal had fewer larger fields relative to the Pareto. The lognormal also resulted in a smaller number of small fields relative to the Pareto. For the Permian Basin case study presented here, reserve addition costs were 20% higher with the lognormal size assumption. ?? 2002 International Association for Mathematical Geology.

Structural mode significance using INCA. [Interactive Controls Analysis computer program

NASA Technical Reports Server (NTRS)

Bauer, Frank H.; Downing, John P.; Thorpe, Christopher J.

1990-01-01

Structural finite element models are often too large to be used in the design and analysis of control systems. Model reduction techniques must be applied to reduce the structural model to manageable size. In the past, engineers either performed the model order reduction by hand or used distinct computer programs to retrieve the data, to perform the significance analysis and to reduce the order of the model. To expedite this process, the latest version of INCA has been expanded to include an interactive graphical structural mode significance and model order reduction capability.

Gait Analysis Laboratory

NASA Technical Reports Server (NTRS)

1976-01-01

Complete motion analysis laboratory has evolved out of analyzing walking patterns of crippled children at Stanford Children's Hospital. Data is collected by placing tiny electrical sensors over muscle groups of child's legs and inserting step-sensing switches in soles of shoes. Miniature radio transmitters send signals to receiver for continuous recording of abnormal walking pattern. Engineers are working to apply space electronics miniaturization techniques to reduce size and weight of telemetry system further as well as striving to increase signal bandwidth so analysis can be performed faster and more accurately using a mini-computer.

Recursive Directional Ligation Approach for Cloning Recombinant Spider Silks.

PubMed

Dinjaski, Nina; Huang, Wenwen; Kaplan, David L

2018-01-01

Recent advances in genetic engineering have provided a route to produce various types of recombinant spider silks. Different cloning strategies have been applied to achieve this goal (e.g., concatemerization, step-by-step ligation, recursive directional ligation). Here we describe recursive directional ligation as an approach that allows for facile modularity and control over the size of the genetic cassettes. This approach is based on sequential ligation of genetic cassettes (monomers) where the junctions between them are formed without interrupting key gene sequences with additional base pairs.

76 FR 68634 - Airworthiness Directives; General Electric Company (GE) CF6 Turbofan Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-07

... Airworthiness Directives; General Electric Company (GE) CF6 Turbofan Engines AGENCY: Federal Aviation... ``(c) This AD applies to * * * and CF6-80A3 turbofan engines with left-hand links * * *.'' to ``(c) This AD applies to * * * and CF6-80A3 turbofan engines, including engines marked on the engine data...

A Vision for Systems Engineering Applied to Wind Energy (Presentation)

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

Felker, F.; Dykes, K.

2015-01-01

This presentation was given at the Third Wind Energy Systems Engineering Workshop on January 14, 2015. Topics covered include the importance of systems engineering, a vision for systems engineering as applied to wind energy, and application of systems engineering approaches to wind energy research and development.

LLIMAS: Revolutionizing integrating modeling and analysis at MIT Lincoln Laboratory

NASA Astrophysics Data System (ADS)

Doyle, Keith B.; Stoeckel, Gerhard P.; Rey, Justin J.; Bury, Mark E.

2017-08-01

MIT Lincoln Laboratory's Integrated Modeling and Analysis Software (LLIMAS) enables the development of novel engineering solutions for advanced prototype systems through unique insights into engineering performance and interdisciplinary behavior to meet challenging size, weight, power, environmental, and performance requirements. LLIMAS is a multidisciplinary design optimization tool that wraps numerical optimization algorithms around an integrated framework of structural, thermal, optical, stray light, and computational fluid dynamics analysis capabilities. LLIMAS software is highly extensible and has developed organically across a variety of technologies including laser communications, directed energy, photometric detectors, chemical sensing, laser radar, and imaging systems. The custom software architecture leverages the capabilities of existing industry standard commercial software and supports the incorporation of internally developed tools. Recent advances in LLIMAS's Structural-Thermal-Optical Performance (STOP), aeromechanical, and aero-optical capabilities as applied to Lincoln prototypes are presented.

Locomotion control of hybrid cockroach robots

PubMed Central

Sanchez, Carlos J.; Chiu, Chen-Wei; Zhou, Yan; González, Jorge M.; Vinson, S. Bradleigh; Liang, Hong

2015-01-01

Natural systems retain significant advantages over engineered systems in many aspects, including size and versatility. In this research, we develop a hybrid robotic system using American (Periplaneta americana) and discoid (Blaberus discoidalis) cockroaches that uses the natural locomotion and robustness of the insect. A tethered control system was firstly characterized using American cockroaches, wherein implanted electrodes were used to apply an electrical stimulus to the prothoracic ganglia. Using this approach, larger discoid cockroaches were engineered into a remotely controlled hybrid robotic system. Locomotion control was achieved through electrical stimulation of the prothoracic ganglia, via a remotely operated backpack system and implanted electrodes. The backpack consisted of a microcontroller with integrated transceiver protocol, and a rechargeable battery. The hybrid discoid roach was able to walk, and turn in response to an electrical stimulus to its nervous system with high repeatability of 60%. PMID:25740855

Creating a Bio-Inspired Solution to Prevent Erosion

NASA Astrophysics Data System (ADS)

Reher, R.; Martinez, A.; Cola, J.; Frost, D.

2016-12-01

Through the study of geophysical sciences, lessons can be developed which allow for the introduction of bio-inspired design and art concepts to K-5 elementary students. Students are placed into an engineering mindset in which they must apply the concepts of bio-geotechnics to observe how we can use nature to prevent and abate erosion. Problems are staged for students using realistic engineering scenarios such as erosion prevention through biomimicry and the study of anchorage characteristics of root structures in regard to stability of soil. Specifically, a lesson is introduced where students research, learn, and present information about bio-inspired designs to understand these concepts. They lean how plant roots differ in size and shape to stabilize soil. In addition, students perform a series of hands-on experiments which demonstrate how bio-cements and roots can slow erosion.

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... standards apply as specified in 40 CFR part 94 for engines originally manufactured in model years 2004...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... standards apply as specified in 40 CFR part 94 for engines originally manufactured in model years 2004...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

Two coupled, driven Ising spin systems working as an engine.

PubMed

Basu, Debarshi; Nandi, Joydip; Jayannavar, A M; Marathe, Rahul

2017-05-01

Miniaturized heat engines constitute a fascinating field of current research. Many theoretical and experimental studies are being conducted that involve colloidal particles in harmonic traps as well as bacterial baths acting like thermal baths. These systems are micron-sized and are subjected to large thermal fluctuations. Hence, for these systems average thermodynamic quantities, such as work done, heat exchanged, and efficiency, lose meaning unless otherwise supported by their full probability distributions. Earlier studies on microengines are concerned with applying Carnot or Stirling engine protocols to miniaturized systems, where system undergoes typical two isothermal and two adiabatic changes. Unlike these models we study a prototype system of two classical Ising spins driven by time-dependent, phase-different, external magnetic fields. These spins are simultaneously in contact with two heat reservoirs at different temperatures for the full duration of the driving protocol. Performance of the model as an engine or a refrigerator depends only on a single parameter, namely the phase between two external drivings. We study this system in terms of fluctuations in efficiency and coefficient of performance (COP). We find full distributions of these quantities numerically and study the tails of these distributions. We also study reliability of the engine. We find the fluctuations dominate mean values of efficiency and COP, and their probability distributions are broad with power law tails.

Designing biomaterials with immunomodulatory properties for tissue engineering and regenerative medicine

PubMed Central

Andorko, James I.

2017-01-01

Abstract Recent research in the vaccine and immunotherapy fields has revealed that biomaterials have the ability to activate immune pathways, even in the absence of other immune‐stimulating signals. Intriguingly, new studies reveal these responses are influenced by the physicochemical properties of the material. Nearly all of this work has been done in the vaccine and immunotherapy fields, but there is tremendous opportunity to apply this same knowledge to tissue engineering and regenerative medicine. This review discusses recent findings that reveal how material properties—size, shape, chemical functionality—impact immune response, and links these changes to emerging opportunities in tissue engineering and regenerative medicine. We begin by discussing what has been learned from studies conducted in the contexts of vaccines and immunotherapies. Next, research is highlighted that elucidates the properties of materials that polarize innate immune cells, including macrophages and dendritic cells, toward either inflammatory or wound healing phenotypes. We also discuss recent studies demonstrating that scaffolds used in tissue engineering applications can influence cells of the adaptive immune system—B and T cell lymphocytes—to promote regenerative tissue microenvironments. Through greater study of the intrinsic immunogenic features of implantable materials and scaffolds, new translational opportunities will arise to better control tissue engineering and regenerative medicine applications. PMID:28932817

Two coupled, driven Ising spin systems working as an engine

NASA Astrophysics Data System (ADS)

Basu, Debarshi; Nandi, Joydip; Jayannavar, A. M.; Marathe, Rahul

2017-05-01

Miniaturized heat engines constitute a fascinating field of current research. Many theoretical and experimental studies are being conducted that involve colloidal particles in harmonic traps as well as bacterial baths acting like thermal baths. These systems are micron-sized and are subjected to large thermal fluctuations. Hence, for these systems average thermodynamic quantities, such as work done, heat exchanged, and efficiency, lose meaning unless otherwise supported by their full probability distributions. Earlier studies on microengines are concerned with applying Carnot or Stirling engine protocols to miniaturized systems, where system undergoes typical two isothermal and two adiabatic changes. Unlike these models we study a prototype system of two classical Ising spins driven by time-dependent, phase-different, external magnetic fields. These spins are simultaneously in contact with two heat reservoirs at different temperatures for the full duration of the driving protocol. Performance of the model as an engine or a refrigerator depends only on a single parameter, namely the phase between two external drivings. We study this system in terms of fluctuations in efficiency and coefficient of performance (COP). We find full distributions of these quantities numerically and study the tails of these distributions. We also study reliability of the engine. We find the fluctuations dominate mean values of efficiency and COP, and their probability distributions are broad with power law tails.

40 CFR 1048.401 - What testing requirements apply to my engines that have gone into service?

Code of Federal Regulations, 2010 CFR

2010-07-01

... engines that have gone into service? 1048.401 Section 1048.401 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES Testing In-use Engines § 1048.401 What testing requirements apply to my engines that have...

34 CFR 637.4 - What definitions apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Engineering Improvement Program? 637.4 Section 637.4 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.4 What definitions apply to the Minority Science and Engineering... American origin), Pacific Islander or other ethnic group underrepresented in science and engineering...

34 CFR 637.4 - What definitions apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Engineering Improvement Program? 637.4 Section 637.4 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.4 What definitions apply to the Minority Science and Engineering... American origin), Pacific Islander or other ethnic group underrepresented in science and engineering...

34 CFR 637.4 - What definitions apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Engineering Improvement Program? 637.4 Section 637.4 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.4 What definitions apply to the Minority Science and Engineering... American origin), Pacific Islander or other ethnic group underrepresented in science and engineering...

34 CFR 637.4 - What definitions apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Engineering Improvement Program? 637.4 Section 637.4 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.4 What definitions apply to the Minority Science and Engineering... American origin), Pacific Islander or other ethnic group underrepresented in science and engineering...

34 CFR 637.4 - What definitions apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Engineering Improvement Program? 637.4 Section 637.4 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.4 What definitions apply to the Minority Science and Engineering... American origin), Pacific Islander or other ethnic group underrepresented in science and engineering...

Possible role of mechanical force in regulating regeneration of the vascularized fat flap inside a tissue engineering chamber.

PubMed

Ye, Yuan; Yuan, Yi; Lu, Feng; Gao, Jianhua

2015-12-01

In plastic and reconstructive surgery, adipose tissue is widely used as effective filler for tissue defects. Strategies for treating soft tissue deficiency, which include free adipose tissue grafts, use of hyaluronic acid, collagen injections, and implantation of synthetic materials, have several clinical limitations. With the aim of overcoming these limitations, researchers have recently utilized tissue engineering chambers to produce large volumes of engineered vascularized fat tissue. However, the process of growing fat tissue in a chamber is still relatively limited, and can result in unpredictable or dissatisfactory final tissue volumes. Therefore, detailed understanding of the process is both necessary and urgent. Many studies have shown that mechanical force can change the function of cells via mechanotransduction. Here, we hypothesized that, besides the inflammatory response, one of the key factors to control the regeneration of vascularized fat flap inside a tissue engineering chamber might be the balance of mechanical forces. To test our hypothesis, we intend to change the balance of forces by means of measures in order to make the equilibrium point in favor of the direction of regeneration. If those measures proved to be feasible, they could be applied in clinical practice to engineer vascularized adipose tissue of predictable size and shape, which would in turn help in the advancement of tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

Metal nanoparticles in diesel exhaust derived by in-cylinder melting of detached engine fragments

NASA Astrophysics Data System (ADS)

Liati, Anthi; Pandurangi, Sushant Sunil; Boulouchos, Konstantinos; Schreiber, Daniel; Arroyo Rojas Dasilva, Yadira

2015-01-01

A wide range of environmental and health effects are linked to combustion-generated pollutants related to traffic. Nanoparticles, in particular, are a major concern for humans since they can be inhaled and have potentially toxic effects. The variability and sources of combustion-related nanoparticle pollutants remain inadequately investigated. Here we report the presence of ca. 5-100 nm large Fe3O4 nanoparticles, in form of agglomerates, in diesel exhaust. The mode of occurrence of these nanoparticles, in combination with their chemical composition matching that of steel indicate that they derive by melting of engine fragments in the combustion chamber and subsequent crystallization during cooling. To evaluate this hypothesis, we applied CFD simulations of material transport in the cylinder of a diesel engine, assuming detachment of steel fragments from various sites of the cylinder. The CFD results show that fragments ≤20 μm in size dislodged from the piston surface or from the fuel nozzle interior can be indeed transported to such hot areas of the combustion chamber where they can melt. The simulation results concur with the experimental observations and point out that metal nanoparticle formation by in-cylinder melting of engine fragments can occur in diesel engines. The present study proposes a hitherto neglected formation mechanism of metal nanoparticle emissions from internal combustion engines raising possible environmental and health concerns, especially in urban areas.

40 CFR 1054.640 - What special provisions apply to branded engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What special provisions apply to branded engines? 1054.640 Section 1054.640 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... EQUIPMENT Special Compliance Provisions § 1054.640 What special provisions apply to branded engines? The...

40 CFR 1048.635 - What special provisions apply to branded engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What special provisions apply to branded engines? 1048.635 Section 1048.635 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Compliance Provisions § 1048.635 What special provisions apply to branded engines? The following provisions...

40 CFR 1045.640 - What special provisions apply to branded engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What special provisions apply to branded engines? 1045.640 Section 1045.640 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... VESSELS Special Compliance Provisions § 1045.640 What special provisions apply to branded engines? The...

40 CFR 1039.107 - What evaporative emission standards and requirements apply?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 1048 that apply to spark-ignition engines, as follows: (a) Follow the steps in 40 CFR 1048.245 to show...-IGNITION ENGINES Emission Standards and Related Requirements § 1039.107 What evaporative emission standards and requirements apply? There are no evaporative emission standards for diesel-fueled engines, or...

40 CFR 1051.510 - What special provisions apply for testing ATV engines? [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What special provisions apply for... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Test Procedures § 1051.510 What special provisions apply for testing ATV engines? [Reserved] ...

Coherence and measurement in quantum thermodynamics

PubMed Central

Kammerlander, P.; Anders, J.

2016-01-01

Thermodynamics is a highly successful macroscopic theory widely used across the natural sciences and for the construction of everyday devices, from car engines to solar cells. With thermodynamics predating quantum theory, research now aims to uncover the thermodynamic laws that govern finite size systems which may in addition host quantum effects. Recent theoretical breakthroughs include the characterisation of the efficiency of quantum thermal engines, the extension of classical non-equilibrium fluctuation theorems to the quantum regime and a new thermodynamic resource theory has led to the discovery of a set of second laws for finite size systems. These results have substantially advanced our understanding of nanoscale thermodynamics, however putting a finger on what is genuinely quantum in quantum thermodynamics has remained a challenge. Here we identify information processing tasks, the so-called projections, that can only be formulated within the framework of quantum mechanics. We show that the physical realisation of such projections can come with a non-trivial thermodynamic work only for quantum states with coherences. This contrasts with information erasure, first investigated by Landauer, for which a thermodynamic work cost applies for classical and quantum erasure alike. Repercussions on quantum work fluctuation relations and thermodynamic single-shot approaches are also discussed. PMID:26916503

Coherence and measurement in quantum thermodynamics.

PubMed

Kammerlander, P; Anders, J

2016-02-26

Thermodynamics is a highly successful macroscopic theory widely used across the natural sciences and for the construction of everyday devices, from car engines to solar cells. With thermodynamics predating quantum theory, research now aims to uncover the thermodynamic laws that govern finite size systems which may in addition host quantum effects. Recent theoretical breakthroughs include the characterisation of the efficiency of quantum thermal engines, the extension of classical non-equilibrium fluctuation theorems to the quantum regime and a new thermodynamic resource theory has led to the discovery of a set of second laws for finite size systems. These results have substantially advanced our understanding of nanoscale thermodynamics, however putting a finger on what is genuinely quantum in quantum thermodynamics has remained a challenge. Here we identify information processing tasks, the so-called projections, that can only be formulated within the framework of quantum mechanics. We show that the physical realisation of such projections can come with a non-trivial thermodynamic work only for quantum states with coherences. This contrasts with information erasure, first investigated by Landauer, for which a thermodynamic work cost applies for classical and quantum erasure alike. Repercussions on quantum work fluctuation relations and thermodynamic single-shot approaches are also discussed.

Coherence and measurement in quantum thermodynamics

NASA Astrophysics Data System (ADS)

Kammerlander, P.; Anders, J.

2016-02-01

Thermodynamics is a highly successful macroscopic theory widely used across the natural sciences and for the construction of everyday devices, from car engines to solar cells. With thermodynamics predating quantum theory, research now aims to uncover the thermodynamic laws that govern finite size systems which may in addition host quantum effects. Recent theoretical breakthroughs include the characterisation of the efficiency of quantum thermal engines, the extension of classical non-equilibrium fluctuation theorems to the quantum regime and a new thermodynamic resource theory has led to the discovery of a set of second laws for finite size systems. These results have substantially advanced our understanding of nanoscale thermodynamics, however putting a finger on what is genuinely quantum in quantum thermodynamics has remained a challenge. Here we identify information processing tasks, the so-called projections, that can only be formulated within the framework of quantum mechanics. We show that the physical realisation of such projections can come with a non-trivial thermodynamic work only for quantum states with coherences. This contrasts with information erasure, first investigated by Landauer, for which a thermodynamic work cost applies for classical and quantum erasure alike. Repercussions on quantum work fluctuation relations and thermodynamic single-shot approaches are also discussed.

Contingency power concepts for helicopter turboshaft engine

NASA Technical Reports Server (NTRS)

Hirschkron, R.; Davis, R. H.; Goldstein, D. N.; Haynes, J. F.; Gauntner, J. W.

1984-01-01

Twin helicopter engines are often sized by power requirement of safe mission completion after the failure of one of the two engines. This study was undertaken for NASA Lewis by General Electric Co. to evaluate the merits of special design features to provide a 2-1/2 minute Contingency Power rating, permitting an engine size reduction. The merits of water injection, cooling flow modulation, throttle push and an auxiliary power plant were evaluated using military life cycle cost (LCC) and commercial helicopter direct operating cost (DOC) merit factors in a rubber engine/rubber aircraft scenario.

Recent Developments of Functional Scaffolds for Craniomaxillofacial Bone Tissue Engineering Applications

PubMed Central

Kinoshita, Yukihiko; Maeda, Hatsuhiko

2013-01-01

Autogenous bone grafting remains a gold standard for the reconstruction critical-sized bone defects in the craniomaxillofacial region. Nevertheless, this graft procedure has several disadvantages such as restricted availability, donor-site morbidity, and limitations in regard to fully restoring the complicated three-dimensional structures in the craniomaxillofacial bone. The ultimate goal of craniomaxillofacial bone reconstruction is the regeneration of the physiological bone that simultaneously fulfills both morphological and functional restorations. Developments of tissue engineering in the last two decades have brought such a goal closer to reality. In bone tissue engineering, the scaffolds are fundamental, elemental and mesenchymal stem cells/osteoprogenitor cells and bioactive factors. A variety of scaffolds have been developed and used as spacemakers, biodegradable bone substitutes for transplanting to the new bone, matrices of drug delivery system, or supporting structures enhancing adhesion, proliferation, and matrix production of seeded cells according to the circumstances of the bone defects. However, scaffolds to be clinically completely satisfied have not been developed yet. Development of more functional scaffolds is required to be applied widely to cranio-maxillofacial bone defects. This paper reviews recent trends of scaffolds for crania-maxillofacial bone tissue engineering, including our studies. PMID:24163634

Quantification of Cardiomyocyte Alignment from Three-Dimensional (3D) Confocal Microscopy of Engineered Tissue.

PubMed

Kowalski, William J; Yuan, Fangping; Nakane, Takeichiro; Masumoto, Hidetoshi; Dwenger, Marc; Ye, Fei; Tinney, Joseph P; Keller, Bradley B

2017-08-01

Biological tissues have complex, three-dimensional (3D) organizations of cells and matrix factors that provide the architecture necessary to meet morphogenic and functional demands. Disordered cell alignment is associated with congenital heart disease, cardiomyopathy, and neurodegenerative diseases and repairing or replacing these tissues using engineered constructs may improve regenerative capacity. However, optimizing cell alignment within engineered tissues requires quantitative 3D data on cell orientations and both efficient and validated processing algorithms. We developed an automated method to measure local 3D orientations based on structure tensor analysis and incorporated an adaptive subregion size to account for multiple scales. Our method calculates the statistical concentration parameter, κ, to quantify alignment, as well as the traditional orientational order parameter. We validated our method using synthetic images and accurately measured principal axis and concentration. We then applied our method to confocal stacks of cleared, whole-mount engineered cardiac tissues generated from human-induced pluripotent stem cells or embryonic chick cardiac cells and quantified cardiomyocyte alignment. We found significant differences in alignment based on cellular composition and tissue geometry. These results from our synthetic images and confocal data demonstrate the efficiency and accuracy of our method to measure alignment in 3D tissues.

Dual Microstructure Heat Treatment of a Nickel-Base Disk Alloy Assessed

NASA Technical Reports Server (NTRS)

Gayda, John

2002-01-01

Gas turbine engines for future subsonic aircraft will require nickel-base disk alloys that can be used at temperatures in excess of 1300 F. Smaller turbine engines, with higher rotational speeds, also require disk alloys with high strength. To address these challenges, NASA funded a series of disk programs in the 1990's. Under these initiatives, Honeywell and Allison focused their attention on Alloy 10, a high-strength, nickel-base disk alloy developed by Honeywell for application in the small turbine engines used in regional jet aircraft. Since tensile, creep, and fatigue properties are strongly influenced by alloy grain size, the effect of heat treatment on grain size and the attendant properties were studied in detail. It was observed that a fine grain microstructure offered the best tensile and fatigue properties, whereas a coarse grain microstructure offered the best creep resistance at high temperatures. Therefore, a disk with a dual microstructure, consisting of a fine-grained bore and a coarse-grained rim, should have a high potential for optimal performance. Under NASA's Ultra-Safe Propulsion Project and Ultra-Efficient Engine Technology (UEET) Program, a disk program was initiated at the NASA Glenn Research Center to assess the feasibility of using Alloy 10 to produce a dual-microstructure disk. The objectives of this program were twofold. First, existing dual-microstructure heat treatment (DMHT) technology would be applied and refined as necessary for Alloy 10 to yield the desired grain structure in full-scale forgings appropriate for use in regional gas turbine engines. Second, key mechanical properties from the bore and rim of a DMHT Alloy 10 disk would be measured and compared with conventional heat treatments to assess the benefits of DMHT technology. At Wyman Gordon and Honeywell, an active-cooling DMHT process was used to convert four full-scale Alloy 10 disks to a dual-grain microstructure. The resulting microstructures are illustrated in the photomicrographs. The fine grain size in the bore can be contrasted with the coarse grain size in the rim. Testing (at NASA Glenn) of coupons machined from these disks showed that the DMHT approach did indeed produce a high-strength, fatigue resistant bore and a creep-resistant rim. This combination of properties was previously unobtainable using conventional heat treatments, which produced disks with a uniform grain size. Future plans are in place to spin test a DMHT disk under the Ultra Safe Propulsion Project to assess the viability of this technology at the component level. This testing will include measurements of disk growth at a high temperature as well as the determination of burst speed at an intermediate temperature.

Deposition of Nanostructured Thin Film from Size-Classified Nanoparticles

NASA Technical Reports Server (NTRS)

Camata, Renato P.; Cunningham, Nicholas C.; Seol, Kwang Soo; Okada, Yoshiki; Takeuchi, Kazuo

2003-01-01

Materials comprising nanometer-sized grains (approximately 1_50 nm) exhibit properties dramatically different from those of their homogeneous and uniform counterparts. These properties vary with size, shape, and composition of nanoscale grains. Thus, nanoparticles may be used as building blocks to engineer tailor-made artificial materials with desired properties, such as non-linear optical absorption, tunable light emission, charge-storage behavior, selective catalytic activity, and countless other characteristics. This bottom-up engineering approach requires exquisite control over nanoparticle size, shape, and composition. We describe the design and characterization of an aerosol system conceived for the deposition of size classified nanoparticles whose performance is consistent with these strict demands. A nanoparticle aerosol is generated by laser ablation and sorted according to size using a differential mobility analyzer. Nanoparticles within a chosen window of sizes (e.g., (8.0 plus or minus 0.6) nm) are deposited electrostatically on a surface forming a film of the desired material. The system allows the assembly and engineering of thin films using size-classified nanoparticles as building blocks.

40 CFR 1045.610 - What provisions apply to using engines already certified to Small SI emission standards?

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROPULSION MARINE ENGINES AND VESSELS Special Compliance Provisions § 1045.610 What provisions apply to using... persons in the same manner as if these engines were not used as propulsion marine engines. (d) You may use...

40 CFR 1045.610 - What provisions apply to using engines already certified to Small SI emission standards?

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROPULSION MARINE ENGINES AND VESSELS Special Compliance Provisions § 1045.610 What provisions apply to using... persons in the same manner as if these engines were not used as propulsion marine engines. (d) You may use...

40 CFR 1045.610 - What provisions apply to using engines already certified to Small SI emission standards?

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROPULSION MARINE ENGINES AND VESSELS Special Compliance Provisions § 1045.610 What provisions apply to using... persons in the same manner as if these engines were not used as propulsion marine engines. (d) You may use...

40 CFR 1045.610 - What provisions apply to using engines already certified to Small SI emission standards?

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROPULSION MARINE ENGINES AND VESSELS Special Compliance Provisions § 1045.610 What provisions apply to using... persons in the same manner as if these engines were not used as propulsion marine engines. (d) You may use...

40 CFR 1045.610 - What provisions apply to using engines already certified to Small SI emission standards?

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROPULSION MARINE ENGINES AND VESSELS Special Compliance Provisions § 1045.610 What provisions apply to using... persons in the same manner as if these engines were not used as propulsion marine engines. (d) You may use...

40 CFR 86.1901 - What testing requirements apply to my engines that have gone into service?

Code of Federal Regulations, 2014 CFR

2014-07-01

... VEHICLES AND ENGINES Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86.1901 What testing requirements apply to my engines that have gone into service? (a) If you manufacture diesel heavy... engines that have gone into service? 86.1901 Section 86.1901 Protection of Environment ENVIRONMENTAL...

40 CFR Appendix II to Part 1039 - Steady-State Duty Cycles

Code of Federal Regulations, 2011 CFR

2011-07-01

... Appendix II to Part 1039—Steady-State Duty Cycles (a) The following duty cycles apply for constant-speed engines: (1) The following duty cycle applies for discrete-mode testing: D2 mode number Engine speed...(seconds) Engine speed Torque(percent) 1, 2 1a Steady-state 53 Engine governed 100. 1b Transition 20 Engine...

Development of a Spray System for an Unmanned Aerial Vehicle Platform

DTIC Science & Technology

2008-09-01

Applied Engineering in Agriculture Vol. 25(6): 803‐809 2009 American Society of Agricultural and Biological Engineers ISSN 0883-8542 803...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 804 APPLIED ENGINEERING IN AGRICULTURE non‐chemical or least toxic chemical techniques...and electrically shielded (fig. 4). 806 APPLIED ENGINEERING IN AGRICULTURE Figure 2. Computer‐aided model and design of the tank with baffles, and

Applying results from Physics Education Research in a large first-year service course

NASA Astrophysics Data System (ADS)

Ahrensmeier, Daria

2012-10-01

First-year service courses are among the most challenging teaching appointments, due to factors such as lack of motivation, lack of academic preparation, and huge class size. I will describe how the Labatorial Project at the University of Calgary strives to apply results from Physics Education research on inquiry-based learning, addressing misconceptions, peer instruction etc. to the small group sections of these courses. After a brief overview of the design and implementation of the labatorials for a first-year course for engineering students, I will focus on the aspects of change management and sustainability: how one initial change led to a sequence of related modifications, from the lectures to the exams and TA training, accompanied by a natural process of faculty professional development.

Active space debris removal by using laser propulsion

NASA Astrophysics Data System (ADS)

Rezunkov, Yu. A.

2013-03-01

At present, a few projects on the space debris removal by using highpower lasers are developed. One of the established projects is the ORION proposed by Claude Phipps from Photonics Associates Company and supported by NASA (USA) [1]. But the technical feasibility of the concept is limited by sizes of the debris objects (from 1 to 10 cm) because of a small thrust impulse generated at the laser ablation of the debris materials. At the same time, the removal of rocket upper stages and satellites, which have reached the end of their lives, has been carried out only in a very small number of cases and most of them remain on the Low Earth Orbits (LEO). To reduce the amount of these large-size objects, designing of space systems allowing deorbiting upper rocket stages and removing large-size satellite remnants from economically and scientifically useful orbits to disposal ones is considered. The suggested system is based on high-power laser propulsion. Laser-Orbital Transfer Vehicle (LOTV) with the developed aerospace laser propulsion engine is considered as applied to the problem of mitigation of man-made large-size space debris in LEO.

40 CFR 1068.5 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2014 CFR

2014-07-01

... engineering judgment? 1068.5 Section 1068.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... PROGRAMS Applicability and Miscellaneous Provisions § 1068.5 How must manufacturers apply good engineering judgment? (a) You must use good engineering judgment for decisions related to any requirements under this...

40 CFR 59.603 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2013 CFR

2013-07-01

... engineering judgment? 59.603 Section 59.603 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... and Applicability § 59.603 How must manufacturers apply good engineering judgment? (a) In addition to other requirements and prohibitions set forth in this subpart, you must use good engineering judgment...

40 CFR 59.603 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2014 CFR

2014-07-01

... engineering judgment? 59.603 Section 59.603 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... and Applicability § 59.603 How must manufacturers apply good engineering judgment? (a) In addition to other requirements and prohibitions set forth in this subpart, you must use good engineering judgment...

40 CFR 1068.5 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2012 CFR

2012-07-01

... engineering judgment? 1068.5 Section 1068.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... PROGRAMS Applicability and Miscellaneous Provisions § 1068.5 How must manufacturers apply good engineering judgment? (a) You must use good engineering judgment for decisions related to any requirements under this...

40 CFR 59.603 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2011 CFR

2011-07-01

... engineering judgment? 59.603 Section 59.603 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... and Applicability § 59.603 How must manufacturers apply good engineering judgment? (a) In addition to other requirements and prohibitions set forth in this subpart, you must use good engineering judgment...

40 CFR 1068.5 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2013 CFR

2013-07-01

... engineering judgment? 1068.5 Section 1068.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... PROGRAMS Applicability and Miscellaneous Provisions § 1068.5 How must manufacturers apply good engineering judgment? (a) You must use good engineering judgment for decisions related to any requirements under this...

40 CFR 59.603 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2010 CFR

2010-07-01

... engineering judgment? 59.603 Section 59.603 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... and Applicability § 59.603 How must manufacturers apply good engineering judgment? (a) In addition to other requirements and prohibitions set forth in this subpart, you must use good engineering judgment...

40 CFR 1068.5 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2010 CFR

2010-07-01

... engineering judgment? 1068.5 Section 1068.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Miscellaneous Provisions § 1068.5 How must manufacturers apply good engineering judgment? (a) You must use good engineering judgment for decisions related to any requirements under this chapter. This includes your...

40 CFR 59.603 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2012 CFR

2012-07-01

... engineering judgment? 59.603 Section 59.603 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... and Applicability § 59.603 How must manufacturers apply good engineering judgment? (a) In addition to other requirements and prohibitions set forth in this subpart, you must use good engineering judgment...

40 CFR 1068.5 - How must manufacturers apply good engineering judgment?

Code of Federal Regulations, 2011 CFR

2011-07-01

... engineering judgment? 1068.5 Section 1068.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Miscellaneous Provisions § 1068.5 How must manufacturers apply good engineering judgment? (a) You must use good engineering judgment for decisions related to any requirements under this chapter. This includes your...

OCR enhancement through neighbor embedding and fast approximate nearest neighbors

NASA Astrophysics Data System (ADS)

Smith, D. C.

2012-10-01

Generic optical character recognition (OCR) engines often perform very poorly in transcribing scanned low resolution (LR) text documents. To improve OCR performance, we apply the Neighbor Embedding (NE) single-image super-resolution (SISR) technique to LR scanned text documents to obtain high resolution (HR) versions, which we subsequently process with OCR. For comparison, we repeat this procedure using bicubic interpolation (BI). We demonstrate that mean-square errors (MSE) in NE HR estimates do not increase substantially when NE is trained in one Latin font style and tested in another, provided both styles belong to the same font category (serif or sans serif). This is very important in practice, since for each font size, the number of training sets required for each category may be reduced from dozens to just one. We also incorporate randomized k-d trees into our NE implementation to perform approximate nearest neighbor search, and obtain a 1000x speed up of our original NE implementation, with negligible MSE degradation. This acceleration also made it practical to combine all of our size-specific NE Latin models into a single Universal Latin Model (ULM). The ULM eliminates the need to determine the unknown font category and size of an input LR text document and match it to an appropriate model, a very challenging task, since the dpi (pixels per inch) of the input LR image is generally unknown. Our experiments show that OCR character error rates (CER) were over 90% when we applied the Tesseract OCR engine to LR text documents (scanned at 75 dpi and 100 dpi) in the 6-10 pt range. By contrast, using k-d trees and the ULM, CER after NE preprocessing averaged less than 7% at 3x (100 dpi LR scanning) and 4x (75 dpi LR scanning) magnification, over an order of magnitude improvement. Moreover, CER after NE preprocessing was more that 6 times lower on average than after BI preprocessing.

A comprehensive and scalable database search system for metaproteomics.

PubMed

Chatterjee, Sandip; Stupp, Gregory S; Park, Sung Kyu Robin; Ducom, Jean-Christophe; Yates, John R; Su, Andrew I; Wolan, Dennis W

2016-08-16

Mass spectrometry-based shotgun proteomics experiments rely on accurate matching of experimental spectra against a database of protein sequences. Existing computational analysis methods are limited in the size of their sequence databases, which severely restricts the proteomic sequencing depth and functional analysis of highly complex samples. The growing amount of public high-throughput sequencing data will only exacerbate this problem. We designed a broadly applicable metaproteomic analysis method (ComPIL) that addresses protein database size limitations. Our approach to overcome this significant limitation in metaproteomics was to design a scalable set of sequence databases assembled for optimal library querying speeds. ComPIL was integrated with a modified version of the search engine ProLuCID (termed "Blazmass") to permit rapid matching of experimental spectra. Proof-of-principle analysis of human HEK293 lysate with a ComPIL database derived from high-quality genomic libraries was able to detect nearly all of the same peptides as a search with a human database (~500x fewer peptides in the database), with a small reduction in sensitivity. We were also able to detect proteins from the adenovirus used to immortalize these cells. We applied our method to a set of healthy human gut microbiome proteomic samples and showed a substantial increase in the number of identified peptides and proteins compared to previous metaproteomic analyses, while retaining a high degree of protein identification accuracy and allowing for a more in-depth characterization of the functional landscape of the samples. The combination of ComPIL with Blazmass allows proteomic searches to be performed with database sizes much larger than previously possible. These large database searches can be applied to complex meta-samples with unknown composition or proteomic samples where unexpected proteins may be identified. The protein database, proteomic search engine, and the proteomic data files for the 5 microbiome samples characterized and discussed herein are open source and available for use and additional analysis.

Multi-fuel rotary engine for general aviation aircraft

NASA Technical Reports Server (NTRS)

Jones, C.; Ellis, D. R.; Meng, P. R.

1983-01-01

Design studies of advanced multifuel general aviation and commuter aircraft rotary stratified charge engines are summarized. Conceptual design studies were performed at two levels of technology, on advanced general aviation engines sized to provide 186/250 shaft kW/hp under cruise conditions at 7620 (25000 m/ft) altitude. A follow on study extended the results to larger (2500 hp max.) engine sizes suitable for applications such as commuter transports and helicopters. The study engine designs were derived from relevant engine development background including both prior and recent engine test results using direct injected unthrottled rotary engine technology. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 27 to 33 percent fuel economy improvement for the rotary engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed.

An expert system based software sizing tool, phase 2

NASA Technical Reports Server (NTRS)

Friedlander, David

1990-01-01

A software tool was developed for predicting the size of a future computer program at an early stage in its development. The system is intended to enable a user who is not expert in Software Engineering to estimate software size in lines of source code with an accuracy similar to that of an expert, based on the program's functional specifications. The project was planned as a knowledge based system with a field prototype as the goal of Phase 2 and a commercial system planned for Phase 3. The researchers used techniques from Artificial Intelligence and knowledge from human experts and existing software from NASA's COSMIC database. They devised a classification scheme for the software specifications, and a small set of generic software components that represent complexity and apply to large classes of programs. The specifications are converted to generic components by a set of rules and the generic components are input to a nonlinear sizing function which makes the final prediction. The system developed for this project predicted code sizes from the database with a bias factor of 1.06 and a fluctuation factor of 1.77, an accuracy similar to that of human experts but without their significant optimistic bias.

40 CFR 1042.670 - Special provisions for gas turbine engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND VESSELS Special Compliance Provisions § 1042.670 Special provisions for gas turbine engines. The provisions of this section apply for gas turbine engines. (a) Implementation schedule. The requirements of this part do not apply for gas turbine engines below 600 kW before the 2014 model year. The...

40 CFR 1042.670 - Special provisions for gas turbine engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... AND VESSELS Special Compliance Provisions § 1042.670 Special provisions for gas turbine engines. The provisions of this section apply for gas turbine engines. (a) Implementation schedule. The requirements of this part do not apply for gas turbine engines below 600 kW before the 2014 model year. The...

40 CFR 1039.645 - What special provisions apply to engines used for transportation refrigeration units?

Code of Federal Regulations, 2010 CFR

2010-07-01

... engines used for transportation refrigeration units? 1039.645 Section 1039.645 Protection of Environment... apply to engines used for transportation refrigeration units? Manufacturers may choose to use the provisions of this section for engines used in transportation refrigeration units (TRUs). The operating...

40 CFR 1039.645 - What special provisions apply to engines used for transportation refrigeration units?

Code of Federal Regulations, 2014 CFR

2014-07-01

... engines used for transportation refrigeration units? 1039.645 Section 1039.645 Protection of Environment... apply to engines used for transportation refrigeration units? Manufacturers may choose to use the provisions of this section for engines used in transportation refrigeration units (TRUs). The operating...

40 CFR 1039.645 - What special provisions apply to engines used for transportation refrigeration units?

Code of Federal Regulations, 2012 CFR

2012-07-01

... engines used for transportation refrigeration units? 1039.645 Section 1039.645 Protection of Environment... apply to engines used for transportation refrigeration units? Manufacturers may choose to use the provisions of this section for engines used in transportation refrigeration units (TRUs). The operating...

40 CFR 1039.645 - What special provisions apply to engines used for transportation refrigeration units?

Code of Federal Regulations, 2013 CFR

2013-07-01

... engines used for transportation refrigeration units? 1039.645 Section 1039.645 Protection of Environment... apply to engines used for transportation refrigeration units? Manufacturers may choose to use the provisions of this section for engines used in transportation refrigeration units (TRUs). The operating...

40 CFR 1039.645 - What special provisions apply to engines used for transportation refrigeration units?

Code of Federal Regulations, 2011 CFR

2011-07-01

... engines used for transportation refrigeration units? 1039.645 Section 1039.645 Protection of Environment... apply to engines used for transportation refrigeration units? Manufacturers may choose to use the provisions of this section for engines used in transportation refrigeration units (TRUs). The operating...

Small gas turbine engine technology

NASA Technical Reports Server (NTRS)

Niedzwiecki, Richard W.; Meitner, Peter L.

1988-01-01

Performance of small gas turbine engines in the 250 to 1,000 horsepower size range is significantly lower than that of large engines. Engines of this size are typically used in rotorcraft, commutercraft, general aviation, and cruise missile applications. Principal reasons for the lower efficiencies of a smaller engine are well known: component efficients are lower by as much as 8 to 10 percentage points because of size effects. Small engines are designed for lower cycle pressures and temperatures because of smaller blading and cooling limitations. The highly developed analytical and manufacturing techniques evolved for large engines are not directly transferrable to small engines. Thus, it was recognized that a focused effort addressing technologies for small engies was needed and could significantly impact their performance. Recently, in-house and contract studies were undertaken at the NASA Lewis Research Center to identify advanced engine cycle and component requirements for substantial performance improvement of small gas turbines for projected year 2000 applications. The results of both in-house research and contract studies are presented. In summary, projected fuel savings of 22 to 42 percent could be obtained. Accompanying direct operating cost reductions of 11 to 17 percent, depending on fuel cost, were also estimated. High payoff technologies are identified for all engine applications, and recent results of experimental research to evolve the high payoff technologies are described.

Charge-based separation of particles and cells with similar sizes via the wall-induced electrical lift.

PubMed

Thomas, Cory; Lu, Xinyu; Todd, Andrew; Raval, Yash; Tzeng, Tzuen-Rong; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

2017-01-01

The separation of particles and cells in a uniform mixture has been extensively studied as a necessity in many chemical and biomedical engineering and research fields. This work demonstrates a continuous charge-based separation of fluorescent and plain spherical polystyrene particles with comparable sizes in a ψ-shaped microchannel via the wall-induced electrical lift. The effects of both the direct current electric field in the main-branch and the electric field ratio in between the inlet branches for sheath fluid and particle mixture are investigated on this electrokinetic particle separation. A Lagrangian tracking method based theoretical model is also developed to understand the particle transport in the microchannel and simulate the parametric effects on particle separation. Moreover, the demonstrated charge-based separation is applied to a mixture of yeast cells and polystyrene particles with similar sizes. Good separation efficiency and purity are achieved for both the cells and the particles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Real-time particulate mass measurement based on laser scattering

NASA Astrophysics Data System (ADS)

Rentz, Julia H.; Mansur, David; Vaillancourt, Robert; Schundler, Elizabeth; Evans, Thomas

2005-11-01

OPTRA has developed a new approach to the determination of particulate size distribution from a measured, composite, laser angular scatter pattern. Drawing from the field of infrared spectroscopy, OPTRA has employed a multicomponent analysis technique which uniquely recognizes patterns associated with each particle size "bin" over a broad range of sizes. The technique is particularly appropriate for overlapping patterns where large signals are potentially obscuring weak ones. OPTRA has also investigated a method for accurately training the algorithms without the use of representative particles for any given application. This streamlined calibration applies a one-time measured "instrument function" to theoretical Mie patterns to create the training data for the algorithms. OPTRA has demonstrated this algorithmic technique on a compact, rugged, laser scatter sensor head we developed for gas turbine engine emissions measurements. The sensor contains a miniature violet solid state laser and an array of silicon photodiodes, both of which are commercial off the shelf. The algorithmic technique can also be used with any commercially available laser scatter system.

Bone regeneration by polyhedral microcrystals from silkworm virus

PubMed Central

Matsumoto, Goichi; Ueda, Takayo; Shimoyama, Junko; Ijiri, Hiroshi; Omi, Yasushi; Yube, Hisato; Sugita, Yoshihiko; Kubo, Katsutoshi; Maeda, Hatsuhiko; Kinoshita, Yukihiko; Arias, Duverney Gaviria; Shimabukuro, Junji; Kotani, Eiji; Kawamata, Shin; Mori, Hajime

2012-01-01

Bombyx mori cypovirus is a major pathogen which causes significant losses in silkworm cocoon harvests because the virus particles are embedded in micrometer-sized protein crystals called polyhedra and can remain infectious in harsh environmental conditions for years. But the remarkable stability of polyhedra can be applied on slow-release carriers of cytokines for tissue engineering. Here we show the complete healing in critical-sized bone defects by bone morphogenetic protein-2 (BMP-2) encapsulated polyhedra. Although absorbable collagen sponge (ACS) safely and effectively delivers recombinant human BMP-2 (rhBMP-2) into healing tissue, the current therapeutic regimens release rhBMP-2 at an initially high rate after which the rate declines rapidly. ACS impregnated with BMP-2 polyhedra had enough osteogenic activity to promote complete healing in critical-sized bone defects, but ACS with a high dose of rhBMP-2 showed incomplete bone healing, indicating that polyhedral microcrystals containing BMP-2 promise to advance the state of the art of bone healing. PMID:23226833

Twice electric field poling for engineering multiperiodic Hex-PPLN microstructures

NASA Astrophysics Data System (ADS)

Pagliarulo, Vito; Gennari, Oriella; Rega, Romina; Mecozzi, Laura; Grilli, Simonetta; Ferraro, Pietro

2018-05-01

Satellite bulk ferroelectric domains were observed everywhere around the larger main inverted ferroelectric domains when a Twice Electric Field Poling (TEFP) process is applied on a z-cut lithium niobate substrate. TEFP approach can be very advantageous for engineering multiperiodic poled microstructures in ferroelectrics. In fact, it is very difficult in the experimental practice to avoid underpoling and/or overpoling when structures with different sizes are requested in the same crystal. TEFP was applied to photoresist patterned crystal with 100 μm period and then a second EP step, with a ten-times smaller periodicity of 10 μm, was accomplished on the same sample. The intriguing fact is that the shorter 10 μm pattern disappeared everywhere except that around the larger satellite ferroelectric domains. The formation of this double-periodicity in the reversed ferroelectric domains occurs very easily and in repeatedly way. We have experimentally investigated the formation of such HePPLN structures by an interference microscopy in digital holography (DH) modality. The reported results demonstrate the possibility of fabricating multi-periodic structures and open the way to investigate the possibility to achieve hierarchical PPLN structures by multiple subsequent electric poling processes.

A modular modulation method for achieving increases in metabolite production.

PubMed

Acerenza, Luis; Monzon, Pablo; Ortega, Fernando

2015-01-01

Increasing the production of overproducing strains represents a great challenge. Here, we develop a modular modulation method to determine the key steps for genetic manipulation to increase metabolite production. The method consists of three steps: (i) modularization of the metabolic network into two modules connected by linking metabolites, (ii) change in the activity of the modules using auxiliary rates producing or consuming the linking metabolites in appropriate proportions and (iii) determination of the key modules and steps to increase production. The mathematical formulation of the method in matrix form shows that it may be applied to metabolic networks of any structure and size, with reactions showing any kind of rate laws. The results are valid for any type of conservation relationships in the metabolite concentrations or interactions between modules. The activity of the module may, in principle, be changed by any large factor. The method may be applied recursively or combined with other methods devised to perform fine searches in smaller regions. In practice, it is implemented by integrating to the producer strain heterologous reactions or synthetic pathways producing or consuming the linking metabolites. The new procedure may contribute to develop metabolic engineering into a more systematic practice. © 2015 American Institute of Chemical Engineers.

Study of noise transmission through double wall aircraft windows

NASA Technical Reports Server (NTRS)

Vaicaitis, R.

1983-01-01

Analytical and experimental procedures were used to predict the noise transmitted through double wall windows into the cabin of a twin-engine G/A aircraft. The analytical model was applied to optimize cabin noise through parametric variation of the structural and acoustic parameters. The parametric study includes mass addition, increase in plexiglass thickness, decrease in window size, increase in window cavity depth, depressurization of the space between the two window plates, replacement of the air cavity with a transparent viscoelastic material, change in stiffness of the plexiglass material, and different absorptive materials for the interior walls of the cabin. It was found that increasing the exterior plexiglass thickness and/or decreasing the total window size could achieve the proper amount of noise reduction for this aircraft. The total added weight to the aircraft is then about 25 lbs.

Index Compression and Efficient Query Processing in Large Web Search Engines

ERIC Educational Resources Information Center

Ding, Shuai

2013-01-01

The inverted index is the main data structure used by all the major search engines. Search engines build an inverted index on their collection to speed up query processing. As the size of the web grows, the length of the inverted list structures, which can easily grow to hundreds of MBs or even GBs for common terms (roughly linear in the size of…

Development and tuning of an original search engine for patent libraries in medicinal chemistry.

PubMed

Pasche, Emilie; Gobeill, Julien; Kreim, Olivier; Oezdemir-Zaech, Fatma; Vachon, Therese; Lovis, Christian; Ruch, Patrick

2014-01-01

The large increase in the size of patent collections has led to the need of efficient search strategies. But the development of advanced text-mining applications dedicated to patents of the biomedical field remains rare, in particular to address the needs of the pharmaceutical & biotech industry, which intensively uses patent libraries for competitive intelligence and drug development. We describe here the development of an advanced retrieval engine to search information in patent collections in the field of medicinal chemistry. We investigate and combine different strategies and evaluate their respective impact on the performance of the search engine applied to various search tasks, which covers the putatively most frequent search behaviours of intellectual property officers in medical chemistry: 1) a prior art search task; 2) a technical survey task; and 3) a variant of the technical survey task, sometimes called known-item search task, where a single patent is targeted. The optimal tuning of our engine resulted in a top-precision of 6.76% for the prior art search task, 23.28% for the technical survey task and 46.02% for the variant of the technical survey task. We observed that co-citation boosting was an appropriate strategy to improve prior art search tasks, while IPC classification of queries was improving retrieval effectiveness for technical survey tasks. Surprisingly, the use of the full body of the patent was always detrimental for search effectiveness. It was also observed that normalizing biomedical entities using curated dictionaries had simply no impact on the search tasks we evaluate. The search engine was finally implemented as a web-application within Novartis Pharma. The application is briefly described in the report. We have presented the development of a search engine dedicated to patent search, based on state of the art methods applied to patent corpora. We have shown that a proper tuning of the system to adapt to the various search tasks clearly increases the effectiveness of the system. We conclude that different search tasks demand different information retrieval engines' settings in order to yield optimal end-user retrieval.

Development and tuning of an original search engine for patent libraries in medicinal chemistry

PubMed Central

2014-01-01

Background The large increase in the size of patent collections has led to the need of efficient search strategies. But the development of advanced text-mining applications dedicated to patents of the biomedical field remains rare, in particular to address the needs of the pharmaceutical & biotech industry, which intensively uses patent libraries for competitive intelligence and drug development. Methods We describe here the development of an advanced retrieval engine to search information in patent collections in the field of medicinal chemistry. We investigate and combine different strategies and evaluate their respective impact on the performance of the search engine applied to various search tasks, which covers the putatively most frequent search behaviours of intellectual property officers in medical chemistry: 1) a prior art search task; 2) a technical survey task; and 3) a variant of the technical survey task, sometimes called known-item search task, where a single patent is targeted. Results The optimal tuning of our engine resulted in a top-precision of 6.76% for the prior art search task, 23.28% for the technical survey task and 46.02% for the variant of the technical survey task. We observed that co-citation boosting was an appropriate strategy to improve prior art search tasks, while IPC classification of queries was improving retrieval effectiveness for technical survey tasks. Surprisingly, the use of the full body of the patent was always detrimental for search effectiveness. It was also observed that normalizing biomedical entities using curated dictionaries had simply no impact on the search tasks we evaluate. The search engine was finally implemented as a web-application within Novartis Pharma. The application is briefly described in the report. Conclusions We have presented the development of a search engine dedicated to patent search, based on state of the art methods applied to patent corpora. We have shown that a proper tuning of the system to adapt to the various search tasks clearly increases the effectiveness of the system. We conclude that different search tasks demand different information retrieval engines' settings in order to yield optimal end-user retrieval. PMID:24564220

Bioengineered porous composite curcumin/silk scaffolds for cartilage regeneration.

PubMed

Kim, Do Kyung; In Kim, Jeong; Sim, Bo Ra; Khang, Gilson

2017-09-01

Articular cartilage repair is a challenge due to its limited self-repair capacity. Cartilage tissue engineering supports to overcome following injuries or degenerative diseases. Herein, we fabricated the scaffold composed of curcumin and silk fibroin as an appropriate clinical replacement for defected cartilage. The scaffolds were designed to have adequate pore size and mechanical strength for cartilage repair. Cell proliferation, sulfated glycosaminoglycan (sGAG) content and mRNA expression analysis indicated that chondrocytes remained viable and showed its growth ability in the curcumin/silk scaffolds. Especially, in 1mg/ml curcumin/silk scaffold showed higher cell viability rate and extracellular matrix formation than other experimental groups. Furthermore, curcumin/silk scaffold showed its biocompatibility and favorable environment for cartilage repair after transplantation in vivo, as indicated in histological examination results. Overall, the functional composite curcumin/silk scaffold can be applied in cartilage tissue engineering and promising substrate for cartilage repair. Copyright © 2017. Published by Elsevier B.V.

Electrospun materials for affinity-based engineering and drug delivery

NASA Astrophysics Data System (ADS)

Sill, T. J.; von Recum, H. A.

2015-10-01

Electrospinning is a process which can quickly and cheaply create materials of high surface to volume and aspect ratios from many materials, however in application toward drug delivery this can be a strong disadvantage as well. Diffusion of drug is proportional to the thickness of that device. In moving from macro to micro to nano-sized electrospun materials drug release rates change to profiles that are too fast to be therapeutically beneficial. In this work we use molecular interactions to further control the rate of release beyond that capable of diffusion alone. To do this we create materials with molecular pockets, which can "hold" therapeutic drugs through a reversible interaction such as a host/guest complexation. Through these complexes we show we are able to impact delivery of drug from electrospun materials, and also apply them in tissue engineering for the reversible presentation of biomolecules on a fiber surface.

Locomotion control of hybrid cockroach robots.

PubMed

Sanchez, Carlos J; Chiu, Chen-Wei; Zhou, Yan; González, Jorge M; Vinson, S Bradleigh; Liang, Hong

2015-04-06

Natural systems retain significant advantages over engineered systems in many aspects, including size and versatility. In this research, we develop a hybrid robotic system using American (Periplaneta americana) and discoid (Blaberus discoidalis) cockroaches that uses the natural locomotion and robustness of the insect. A tethered control system was firstly characterized using American cockroaches, wherein implanted electrodes were used to apply an electrical stimulus to the prothoracic ganglia. Using this approach, larger discoid cockroaches were engineered into a remotely controlled hybrid robotic system. Locomotion control was achieved through electrical stimulation of the prothoracic ganglia, via a remotely operated backpack system and implanted electrodes. The backpack consisted of a microcontroller with integrated transceiver protocol, and a rechargeable battery. The hybrid discoid roach was able to walk, and turn in response to an electrical stimulus to its nervous system with high repeatability of 60%. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Magnetic bearings: A key technology for advanced rocket engines?

NASA Technical Reports Server (NTRS)

Girault, J. PH.

1992-01-01

For several years, active magnetic bearings (AMB) have demonstrated their capabilities in many fields, from industrial compressors to control wheel suspension for spacecraft. Despite this broad area, no significant advance has been observed in rocket propulsion turbomachinery, where size, efficiency, and cost are crucial design criteria. To this respect, Societe Europeenne de Propulsion (SEP) had funded for several years significant efforts to delineate the advantages and drawbacks of AMB applied to rocket propulsion systems. Objectives of this work, relative technological basis, and improvements are described and illustrated by advanced turbopump layouts. Profiting from the advantages of compact design in cryogenic environments, the designs show considerable improvements in engine life, performances, and reliability. However, these conclusions should still be tempered by high recurrent costs, mainly due to the space-rated electronics. Development work focused on this point and evolution of electronics show the possibility to decrease production costs by an order of magnitude.

Profiles of Successful and Unsuccessful Graduate Engineering Management Students.

DTIC Science & Technology

1983-09-01

AFIT GPA 24. AFIT GPA in the following categories: a. Applied engineering b. Socio-humanistic c. Analytical The next chapter is a review of the...Deficiency (1- None, 2- GPA, 3- Class(s), 4- Thesis, AI G5- 2&3, 6- 2,3,&4, 7- 3&4, 8- 2&4) ______AFIT GPA 1-___GPA for Applied Engineering Courses GPA...50 AFIT Cumulative GPA 51 - 54 Applied Engineering GPA -J 55 - 58 Socio-Humanistic GPA 59 - 62 Analytical GPA 107 361173320500620

Applications guide for waste heat recovery

NASA Technical Reports Server (NTRS)

Moynihan, P. I.

1983-01-01

The state-of-the-art of commercially available organic Rankine cycle (ORC) hardware from a literature search and industry survey is assessed. Engineering criteria for applying ORC technology are established, and a set of nomograms to enable the rapid sizing of the equipment is presented. A comparison of an ORC system with conventional heat recovery techniques can be made with a nomogram developed for a recuperative heat exchanger. A graphical technique for evaluating the economic aspects of an ORC system and conventional heat recovery method is discussed: also included is a description of anticipated future trends in organic Rankine cycle R&D.

Time Dependent Simulation of Turbopump Flows

NASA Technical Reports Server (NTRS)

Kiris, Cetin C.; Kwak, Dochan; Chan, William; Williams, Robert

2001-01-01

The objective of this viewgraph presentation is to enhance incompressible flow simulation capability for developing aerospace vehicle components, especially unsteady flow phenomena associated with high speed turbo pumps. Unsteady Space Shuttle Main Engine (SSME)-rig1 1 1/2 rotations are completed for the 34.3 million grid points model. The moving boundary capability is obtained by using the DCF module. MLP shared memory parallelism has been implemented and benchmarked in INS3D. The scripting capability from CAD geometry to solution is developed. Data compression is applied to reduce data size in post processing and fluid/structure coupling is initiated.

[Experimental study on particle size distributions of an engine fueled with blends of biodiesel].

PubMed

Lu, Xiao-Ming; Ge, Yun-Shan; Han, Xiu-Kun; Wu, Si-Jin; Zhu, Rong-Fu; He, Chao

2007-04-01

The purpose of this study is to obtain the particle size distributions of an engine fueled biodiesel and its blends. A turbocharged DI diesel engine was tested on a dynamometer. A pump of 80 L/min and fiber glass filters with diameter of 90 mm were used to sample engine particles in exhaust pipe. Sampling duration was 10 minutes. Particle size distributions were measured by a laser diffraction particle size analyzer. Results indicated that higher engine speed resulted in smaller particle sizes and narrower distributions. The modes on distribution curves and mode variation were larger with dry samples than with wet samples (dry: around 10 - 12 microm vs. wet: around 4 - 10 microm). At low speed, Sauter mean diameter d32 of dry samples was the biggest with B100, the smallest with diesel fuel, and among them with B20, while at high speed, d32 the biggest with B20, the smallest with B100, and in middle with diesel. Median diameter d(0.5) also reflected the results. Except for 2 000 r/min, d32 of wet with B20 is the biggest, the smallest with diesel, and in middle with B100. The large mode variation resulted in increase of d32.

A plume capture technique for the remote characterization of aircraft engine emissions.

PubMed

Johnson, G R; Mazaheri, M; Ristovski, Z D; Morawska, L

2008-07-01

A technique for capturing and analyzing plumes from unmodified aircraft or other combustion sources under real world conditions is described and applied to the task of characterizing plumes from commercial aircraft during the taxiing phase of the Landing/Take-Off (LTO) cycle. The method utilizes a Plume Capture and Analysis System (PCAS) mounted in a four-wheel drive vehicle which is positioned in the airfield 60 to 180 m downwind of aircraft operations. The approach offers low test turnaround times with the ability to complete careful measurements of particle and gaseous emission factors and sequentially scanned particle size distributions without distortion due to plume concentration fluctuations. These measurements can be performed for individual aircraft movements at five minute intervals. A Plume Capture Device (PCD) collected samples of the naturally diluted plume in a 200 L conductive membrane conforming to a defined shape. Samples from over 60 aircraft movements were collected and analyzed in situ for particulate and gaseous concentrations and for particle size distribution using a Scanning Particle Mobility Sizer (SMPS). Emission factors are derived for particle number, NO(x), and PM2.5 for a widely used commercial aircraft type, Boeing 737 airframes with predominantly CFM56 class engines, during taxiing. The practical advantages of the PCAS include the capacity to perform well targeted and controlled emission factor and size distribution measurements using instrumentation with varying response times within an airport facility, in close proximity to aircraft during their normal operations.

Advanced stratified charge rotary aircraft engine design study

NASA Technical Reports Server (NTRS)

Badgley, P.; Berkowitz, M.; Jones, C.; Myers, D.; Norwood, E.; Pratt, W. B.; Ellis, D. R.; Huggins, G.; Mueller, A.; Hembrey, J. H.

1982-01-01

A technology base of new developments which offered potential benefits to a general aviation engine was compiled and ranked. Using design approaches selected from the ranked list, conceptual design studies were performed of an advanced and a highly advanced engine sized to provide 186/250 shaft Kw/HP under cruise conditions at 7620/25,000 m/ft altitude. These are turbocharged, direct-injected stratified charge engines intended for commercial introduction in the early 1990's. The engine descriptive data includes tables, curves, and drawings depicting configuration, performance, weights and sizes, heat rejection, ignition and fuel injection system descriptions, maintenance requirements, and scaling data for varying power. An engine-airframe integration study of the resulting engines in advanced airframes was performed on a comparative basis with current production type engines. The results show airplane performance, costs, noise & installation factors. The rotary-engined airplanes display substantial improvements over the baseline, including 30 to 35% lower fuel usage.

Downsizing assessment of automotive Stirling engines

NASA Technical Reports Server (NTRS)

Knoll, R. H.; Tew, R. C., Jr.; Klann, J. L.

1983-01-01

A 67 kW (90 hp) Stirling engine design, sized for use in a 1984 1440 kg (3170 lb) automobile was the focal point for developing automotive Stirling engine technology. Since recent trends are towards lighter vehicles, an assessment was made of the applicability of the Stirling technology being developed for smaller, lower power engines. Using both the Philips scaling laws and a Lewis Research Center (Lewis) Stirling engine performance code, dimensional and performance characteristics were determined for a 26 kW (35 hp) and a 37 kW (50 hp) engine for use in a nominal 907 kg (2000 lb) vehicle. Key engine elements were sized and stressed and mechanical layouts were made to ensure mechanical fit and integrity of the engines. Fuel economy estimates indicated that the Stirling engine would maintain a 30 to 45 percent fuel economy advantage comparable spark ignition and diesel powered vehicles in the 1984 period.

The development of a program analysis environment for Ada: Reverse engineering tools for Ada

NASA Technical Reports Server (NTRS)

Cross, James H., II

1991-01-01

The Graphical Representations of Algorithms, Structures, and Processes for Ada (GRASP/Ada) has successfully created and prototyped a new algorithm level graphical representation for Ada software, the Control Structure Diagram (CSD). The primary impetus for creation of the CSD was to improve the comprehension efficiency of Ada software and thus improve reliability and reduce costs. The emphasis was on the automatic generation of the CSD from Ada source code to support reverse engineering and maintenance. The CSD has the potential to replace traditional prettyprinted Ada source code. In Phase 1 of the GRASP/Ada project, the CSD graphical constructs were created and applied manually to several small Ada programs. A prototype (Version 1) was designed and implemented using FLEX and BISON running under the Virtual Memory System (VMS) on a VAX 11-780. In Phase 2, the prototype was improved and ported to the Sun 4 platform under UNIX. A user interface was designed and partially implemented. The prototype was applied successfully to numerous Ada programs ranging in size from several hundred to several thousand lines of source code. In Phase 3 of the project, the prototype was prepared for limited distribution (GRASP/Ada Version 3.0) to facilitate evaluation. The user interface was extensively reworked. The current prototype provides the capability for the user to generate CSD from Ada source code in a reverse engineering mode with a level of flexibility suitable for practical application.

Developing Government Renewable Energy Projects

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

Kurt S. Myers; Thomas L. Baldwin; Jason W. Bush

The US Army Corps of Engineers has retained Idaho National Laboratory (INL) to conduct a study of past INL experiences and complete a report that identifies the processes that are needed for the development of renewable energy projects on government properties. The INL has always maintained expertise in power systems and applied engineering and INL’s renewable energy experiences date back to the 1980’s when our engineers began performing US Air Force wind energy feasibility studies and development projects. Over the last 20+ years of working with Department of Defense and other government agencies to study, design, and build government renewablemore » projects, INL has experienced the do’s and don’ts for being successful with a project. These compiled guidelines for government renewable energy projects could include wind, hydro, geothermal, solar, biomass, or a variety of hybrid systems; however, for the purpose of narrowing the focus of this report, wind projects are the main topic discussed throughout this report. It is our thought that a lot of what is discussed could be applied, possibly with some modifications, to other areas of renewable energy. It is also important to note that individual projects (regardless the type) vary to some degree depending on location, size, and need but in general these concepts and directions can be carried over to the majority of government renewable energy projects. This report focuses on the initial development that needs to occur for any project to be a successful government renewable energy project.« less

Study of The Vector Product using Three Dimensions Vector Card of Engineering in Pathumwan Institute of Technology

NASA Astrophysics Data System (ADS)

Mueanploy, Wannapa

2015-06-01

The objective of this research was to offer the way to improve engineering students in Physics topic of vector product. The sampling of this research was the engineering students at Pathumwan Institute of Technology during the first semester of academic year 2013. 1) Select 120 students by random sampling are asked to fill in a satisfaction questionnaire scale, to select size of three dimensions vector card in order to apply in the classroom. 2) Select 60 students by random sampling to do achievement test and take the test to be used in the classroom. The methods used in analysis of achievement test by the Kuder-Richardson Method (KR- 20). The results show that 12 items of achievement test are appropriate to be applied in the classroom. The achievement test gets Difficulty (P) = 0.40-0.67, Discrimination = 0.33-0.73 and Reliability (r) = 0.70.The experimental in the classroom. 3) Select 60 students by random sampling divide into two groups; group one (the controlled group) with 30 students was chosen to study in the vector product lesson by the regular teaching method. Group two (the experimental group) with 30 students was chosen to learn the vector product lesson with three dimensions vector card. 4) Analyzed data between the controlled group and the experimental group, the result showed that experimental group got higher achievement test than the controlled group significant at .01 level.

Austenite Grain Size Control in Upstream Processing of Niobium Microalloyed Steels by Nano-Scale Precipitate Engineering of TiN-NbC Composite

NASA Astrophysics Data System (ADS)

Subramanian, S. V.; Ma, Xiaoping; Rehman, Kashif

There is a growing demand for thicker gage pipes particularly for off-shore projects. Austenite grain size control in upstream processing before pancaking is essential to obtain excellent DBTT and DWTT properties in thicker gage product. This paper examines the basic science aspects of austenite grain size control by nano-scale precipitate engineering.

Particulate sizing and emission indices for a jet engine exhaust sampled at cruise

NASA Astrophysics Data System (ADS)

Hagen, D.; Whitefield, P.; Paladino, J.; Trueblood, M.; Lilenfeld, H.

Particle size and emission indices measurements for jet engines, primarily the Rolls Royce RB211 engines on a NASA 757 aircraft are reported. These data were used to estimate the fraction of fuel sulfur that was converted to particulates. These measurements were made in-situ with the sampling aircraft several kilometers behind the source. Some complimentary ground measurements on the same source aircraft and engines are also reported. Significant differences are seen between the ground observations and the in-situ observations, indicating that plume processes are changing the aerosol's characteristics.

Multi-fuel rotary engine for general aviation aircraft

NASA Technical Reports Server (NTRS)

Jones, C.; Ellis, D. R.; Meng, P. R.

1983-01-01

Design studies of advanced multifuel general aviation and commuter aircraft rotary stratified charge engines are summarized. Conceptual design studies were performed at two levels of technology, an advanced general aviation engines sized to provide 186/250 shaft kW/hp under cruise conditions at 7620 (25,000 m/ft) altitude. A follow on study extended the results to larger (2500 hp max.) engine sizes suitable for applications such as commuter transports and helicopters. The study engine designs were derived from relevant engine development background including both prior and recent engine test results using direct injected unthrottled rotary engine technology. Aircraft studies, using these resultant growth engines, define anticipated system effects of the performance and power density improvements for both single engine and twin engine airplanes. The calculated results indicate superior system performance and 27 to 33 percent fuel economy improvement for the rotary engine airplanes as compared to equivalent airframe concept designs with current baseline engines. The research and technology activities required to attain the projected engine performance levels are also discussed. Previously announced in STAR as N83-18910

AFRL Solid Propellant Laboratory Explosive Siting and Renovation Lessons Learned

DTIC Science & Technology

2010-07-01

Area 1-30A explosive facility and provide consultation/support during the review process for each of the site plans. • Applied Engineering Services...provided consultation/support during the siting review process. • Applied Engineering Services (AES) Inc. performed a detailed structural, blast, thermal... Applied Engineering Services (AES) Inc. structural, blast, thermal and fragment hazard analysis to determine the appropriate siting values based on

Study of small turbofan engines applicable to general-aviation aircraft

NASA Technical Reports Server (NTRS)

Merrill, G. L.; Burnett, G. A.; Alsworth, C. C.

1973-01-01

The applicability of small turbofan engines to general aviation aircraft is discussed. The engine and engine/airplane performance, weight, size, and cost interrelationships are examined. The effects of specific engine noise constraints are evaluated. The factors inhibiting the use of turbofan engines in general aviation aircraft are identified.

Switchable static friction of piezoelectric composite—silicon wafer contacts

NASA Astrophysics Data System (ADS)

van den Ende, D. A.; Fischer, H. R.; Groen, W. A.; van der Zwaag, S.

2013-04-01

The meso-scale surface roughness of piezoelectric fiber composites can be manipulated by applying an electric field to a piezocomposite with a polished surface. In the absence of an applied voltage, the tips of the embedded piezoelectric ceramic fibers are below the surface of the piezocomposite and a silicon wafer counter surface rests solely on the matrix region of the piezocomposite surface. When actuated, the piezoelectric ceramic fibers protrude from the surface and the wafer rests solely on these protrusions. A threefold decrease in engineering static friction coefficient upon actuation of the piezocomposite was observed: from μ* = 1.65 to μ* = 0.50. These experimental results could be linked to the change in contact surface area and roughness using capillary adhesion theory, which relates the adhesive force to the number and size of the contacting asperities for the different surface states.

Update of GRASP/Ada reverse engineering tools for Ada

NASA Technical Reports Server (NTRS)

Cross, James H., II

1993-01-01

The GRASP/Ada project (Graphical Representations of Algorithms, Structures, and Processes for Ada) successfully created and prototyped a new algorithmic level graphical representation for Ada software, the Control Structure Diagram (CSD). The primary impetus for creation of the CSD was to improve the comprehension efficiency of Ada software and, as a result, improve reliability and reduce costs. The emphasis was on the automatic generation of the CSD from Ada PDL or source code to support reverse engineering and maintenance. The CSD has the potential to replace traditional pretty printed Ada source code. In Phase 1 of the GRASP/Ada project, the CSD graphical constructs were created and applied manually to several small Ada programs. A prototype CSD generator (Version 1) was designed and implemented using FLEX and BISON running under VMS on a VAX 11-780. In Phase 2, the prototype was improved and ported to the Sun 4 platform under UNIX. A user interface was designed and partially implemented using the HP widget toolkit and the X Windows System. In Phase 3, the user interface was extensively reworked using the Athena widget toolkit and X Windows. The prototype was applied successfully to numerous Ada programs ranging in size from several hundred to several thousand lines of source code. Following Phase 3,e two update phases were completed. Update'92 focused on the initial analysis of evaluation data collected from software engineering students at Auburn University and the addition of significant enhancements to the user interface. Update'93 (the current update) focused on the statistical analysis of the data collected in the previous update and preparation of Version 3.4 of the prototype for limited distribution to facilitate further evaluation. The current prototype provides the capability for the user to generate CSD's from Ada PDL or source code in a reverse engineering as well as forward engineering mode with a level of flexibility suitable for practical application. An overview of the GRASP/Ada project with an emphasis on the current update is provided.

Effect of fuel injection pressure on a heavy-duty diesel engine nonvolatile particle emission.

PubMed

Lähde, Tero; Rönkkö, Topi; Happonen, Matti; Söderström, Christer; Virtanen, Annele; Solla, Anu; Kytö, Matti; Rothe, Dieter; Keskinen, Jorma

2011-03-15

The effects of the fuel injection pressure on a heavy-duty diesel engine exhaust particle emissions were studied. Nonvolatile particle size distributions and gaseous emissions were measured at steady-state engine conditions while the fuel injection pressure was changed. An increase in the injection pressure resulted in an increase in the nonvolatile nucleation mode (core) emission at medium and at high loads. At low loads, the core was not detected. Simultaneously, a decrease in soot mode number concentration and size and an increase in the soot mode distribution width were detected at all loads. Interestingly, the emission of the core was independent of the soot mode concentration at load conditions below 50%. Depending on engine load conditions, growth of the geometric mean diameter of the core mode was also detected with increasing injection pressure. The core mode emission and also the size of the mode increased with increasing NOx emission while the soot mode size and emission decreased simultaneously.

Experimental Observations for Determining the Maximum Torque Values to Apply to Composite Components Mechanically Joined With Fasteners (MSFC Center Director's Discretionary Fund Final Report, Proj. 03-13}

NASA Technical Reports Server (NTRS)

Thomas, F. P.

2006-01-01

Aerospace structures utilize innovative, lightweight composite materials for exploration activities. These structural components, due to various reasons including size limitations, manufacturing facilities, contractual obligations, or particular design requirements, will have to be joined. The common methodologies for joining composite components are the adhesively bonded and mechanically fastened joints and, in certain instances, both methods are simultaneously incorporated into the design. Guidelines and recommendations exist for engineers to develop design criteria and analyze and test composites. However, there are no guidelines or recommendations based on analysis or test data to specify a torque or torque range to apply to metallic mechanical fasteners used to join composite components. Utilizing the torque tension machine at NASA s Marshall Space Flight Center, an initial series of tests were conducted to determine the maximum torque that could be applied to a composite specimen. Acoustic emissions were used to nondestructively assess the specimens during the tests and thermographic imaging after the tests.

Band Gap Engineering with Ultralarge Biaxial Strains in Suspended Monolayer MoS2.

PubMed

Lloyd, David; Liu, Xinghui; Christopher, Jason W; Cantley, Lauren; Wadehra, Anubhav; Kim, Brian L; Goldberg, Bennett B; Swan, Anna K; Bunch, J Scott

2016-09-14

We demonstrate the continuous and reversible tuning of the optical band gap of suspended monolayer MoS2 membranes by as much as 500 meV by applying very large biaxial strains. By using chemical vapor deposition (CVD) to grow crystals that are highly impermeable to gas, we are able to apply a pressure difference across suspended membranes to induce biaxial strains. We observe the effect of strain on the energy and intensity of the peaks in the photoluminescence (PL) spectrum and find a linear tuning rate of the optical band gap of 99 meV/%. This method is then used to study the PL spectra of bilayer and trilayer devices under strain and to find the shift rates and Grüneisen parameters of two Raman modes in monolayer MoS2. Finally, we use this result to show that we can apply biaxial strains as large as 5.6% across micron-sized areas and report evidence for the strain tuning of higher level optical transitions.

Preparation and Characterization of a Chitosan/Gelatin/Extracellular Matrix Scaffold and Its Application in Tissue Engineering.

PubMed

Wang, Xiaoyan; Yu, Tailong; Chen, Guanghua; Zou, Jilong; Li, Jianzhong; Yan, Jinglong

2017-03-01

Previous studies have demonstrated that extracellular matrix (ECM) can be used in tissue engineering due to its bioactivity. However, adipose-derived ECM (A-dECM) has never been applied in bone tissue engineering, and it is unknown whether it would be beneficial to the growth of bone marrow mesenchymal stem cells (BMSCs). In this study, we produced chitosan/gelatin/A-dECM (C/G/A-dECM) scaffolds via lyophilization and crosslinking; chitosan/gelatin (C/G) scaffolds were used as controls. For the C/G/A-dECM scaffolds, the average pore size was 285.93 ± 85.39 μm; the average porosity was 90.62 ± 3.65%; the average compressive modulus was 0.87 ± 0.05 kPa; and the average water uptake ratio was 13.73 ± 1.16. In vitro, A-dECM scaffolds could promote the attachment and proliferation of BMSCs. In the same osteogenic-inducing reagent, better osteogenic differentiation could be observed for the C/G/A-dECM scaffolds than for the C/G scaffolds. Thus, we conclude that A-dECM is a promising material and that C/G/A-dECM scaffolds are a candidate for bone tissue engineering.

An Integrated Approach for Aircraft Engine Performance Estimation and Fault Diagnostics

NASA Technical Reports Server (NTRS)

imon, Donald L.; Armstrong, Jeffrey B.

2012-01-01

A Kalman filter-based approach for integrated on-line aircraft engine performance estimation and gas path fault diagnostics is presented. This technique is specifically designed for underdetermined estimation problems where there are more unknown system parameters representing deterioration and faults than available sensor measurements. A previously developed methodology is applied to optimally design a Kalman filter to estimate a vector of tuning parameters, appropriately sized to enable estimation. The estimated tuning parameters can then be transformed into a larger vector of health parameters representing system performance deterioration and fault effects. The results of this study show that basing fault isolation decisions solely on the estimated health parameter vector does not provide ideal results. Furthermore, expanding the number of the health parameters to address additional gas path faults causes a decrease in the estimation accuracy of those health parameters representative of turbomachinery performance deterioration. However, improved fault isolation performance is demonstrated through direct analysis of the estimated tuning parameters produced by the Kalman filter. This was found to provide equivalent or superior accuracy compared to the conventional fault isolation approach based on the analysis of sensed engine outputs, while simplifying online implementation requirements. Results from the application of these techniques to an aircraft engine simulation are presented and discussed.

MULTI-CORE AND OPTICAL PROCESSOR RELATED APPLICATIONS RESEARCH AT OAK RIDGE NATIONAL LABORATORY

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

Barhen, Jacob; Kerekes, Ryan A; ST Charles, Jesse Lee

2008-01-01

High-speed parallelization of common tasks holds great promise as a low-risk approach to achieving the significant increases in signal processing and computational performance required for next generation innovations in reconfigurable radio systems. Researchers at the Oak Ridge National Laboratory have been working on exploiting the parallelization offered by this emerging technology and applying it to a variety of problems. This paper will highlight recent experience with four different parallel processors applied to signal processing tasks that are directly relevant to signal processing required for SDR/CR waveforms. The first is the EnLight Optical Core Processor applied to matched filter (MF) correlationmore » processing via fast Fourier transform (FFT) of broadband Dopplersensitive waveforms (DSW) using active sonar arrays for target tracking. The second is the IBM CELL Broadband Engine applied to 2-D discrete Fourier transform (DFT) kernel for image processing and frequency domain processing. And the third is the NVIDIA graphical processor applied to document feature clustering. EnLight Optical Core Processor. Optical processing is inherently capable of high-parallelism that can be translated to very high performance, low power dissipation computing. The EnLight 256 is a small form factor signal processing chip (5x5 cm2) with a digital optical core that is being developed by an Israeli startup company. As part of its evaluation of foreign technology, ORNL's Center for Engineering Science Advanced Research (CESAR) had access to a precursor EnLight 64 Alpha hardware for a preliminary assessment of capabilities in terms of large Fourier transforms for matched filter banks and on applications related to Doppler-sensitive waveforms. This processor is optimized for array operations, which it performs in fixed-point arithmetic at the rate of 16 TeraOPS at 8-bit precision. This is approximately 1000 times faster than the fastest DSP available today. The optical core performs the matrix-vector multiplications, where the nominal matrix size is 256x256. The system clock is 125MHz. At each clock cycle, 128K multiply-and-add operations per second (OPS) are carried out, which yields a peak performance of 16 TeraOPS. IBM Cell Broadband Engine. The Cell processor is the extraordinary resulting product of 5 years of sustained, intensive R&D collaboration (involving over $400M investment) between IBM, Sony, and Toshiba. Its architecture comprises one multithreaded 64-bit PowerPC processor element (PPE) with VMX capabilities and two levels of globally coherent cache, and 8 synergistic processor elements (SPEs). Each SPE consists of a processor (SPU) designed for streaming workloads, local memory, and a globally coherent direct memory access (DMA) engine. Computations are performed in 128-bit wide single instruction multiple data streams (SIMD). An integrated high-bandwidth element interconnect bus (EIB) connects the nine processors and their ports to external memory and to system I/O. The Applied Software Engineering Research (ASER) Group at the ORNL is applying the Cell to a variety of text and image analysis applications. Research on Cell-equipped PlayStation3 (PS3) consoles has led to the development of a correlation-based image recognition engine that enables a single PS3 to process images at more than 10X the speed of state-of-the-art single-core processors. NVIDIA Graphics Processing Units. The ASER group is also employing the latest NVIDIA graphical processing units (GPUs) to accelerate clustering of thousands of text documents using recently developed clustering algorithms such as document flocking and affinity propagation.« less

40 CFR 1068.260 - What general provisions apply for selling or shipping engines that are not yet in their certified...

Code of Federal Regulations, 2010 CFR

2010-07-01

... certificate holder for the engines in question. We may require you to take specific steps to ensure that such... selling or shipping engines that are not yet in their certified configuration? 1068.260 Section 1068.260... COMPLIANCE PROVISIONS FOR ENGINE PROGRAMS Exemptions and Exclusions § 1068.260 What general provisions apply...

40 CFR 1045.645 - What special provisions apply for converting an engine to use an alternate fuel?

Code of Federal Regulations, 2010 CFR

2010-07-01

... converting an engine to use an alternate fuel? 1045.645 Section 1045.645 Protection of Environment... for converting an engine to use an alternate fuel? A certificate of conformity is no longer valid for.... This section applies if such modifications are done to convert the engine to run on a different fuel...

40 CFR 1054.645 - What special provisions apply for converting an engine to use an alternate fuel?

Code of Federal Regulations, 2010 CFR

2010-07-01

... converting an engine to use an alternate fuel? 1054.645 Section 1054.645 Protection of Environment... apply for converting an engine to use an alternate fuel? A certificate of conformity is no longer valid... fuel type. Such engines may need to be recertified as specified in this section if the certificate is...

Innovative Double Bypass Engine for Increased Performance

NASA Astrophysics Data System (ADS)

Manoharan, Sanjivan

Engines continue to grow in size to meet the current thrust requirements of the civil aerospace industry. Large engines pose significant transportation problems and require them to be split in order to be shipped. Thus, large amounts of time have been spent in researching methods to increase thrust capabilities while maintaining a reasonable engine size. Unfortunately, much of this research has been focused on increasing the performance and efficiencies of individual components while limited research has been done on innovative engine configurations. This thesis focuses on an innovative engine configuration, the High Double Bypass Engine, aimed at increasing fuel efficiency and thrust while maintaining a competitive fan diameter and engine length. The 1-D analysis was done in Excel and then compared to the results from Numerical Propulsion Simulation System (NPSS) software and were found to be within 4% error. Flow performance characteristics were also determined and validated against their criteria.

Digital image processing techniques for the analysis of fuel sprays global pattern

NASA Astrophysics Data System (ADS)

Zakaria, Rami; Bryanston-Cross, Peter; Timmerman, Brenda

2017-12-01

We studied the fuel atomization process of two fuel injectors to be fitted in a new small rotary engine design. The aim was to improve the efficiency of the engine by optimizing the fuel injection system. Fuel sprays were visualised by an optical diagnostic system. Images of fuel sprays were produced under various testing conditions, by changing the line pressure, nozzle size, injection frequency, etc. The atomisers were a high-frequency microfluidic dispensing system and a standard low flow-rate fuel injector. A series of image processing procedures were developed in order to acquire information from the laser-scattering images. This paper presents the macroscopic characterisation of Jet fuel (JP8) sprays. We observed the droplet density distribution, tip velocity, and spray-cone angle against line-pressure and nozzle-size. The analysis was performed for low line-pressure (up to 10 bar) and short injection period (1-2 ms). Local velocity components were measured by applying particle image velocimetry (PIV) on double-exposure images. The discharge velocity was lower in the micro dispensing nozzle sprays and the tip penetration slowed down at higher rates compared to the gasoline injector. The PIV test confirmed that the gasoline injector produced sprays with higher velocity elements at the centre and the tip regions.

Quantum Dot Surface Engineering: Toward Inert Fluorophores with Compact Size and Bright, Stable Emission

PubMed Central

Lim, Sung Jun; Ma, Liang; Schleife, André; Smith, Andrew M.

2016-01-01

The surfaces of colloidal nanocrystals are complex interfaces between solid crystals, coordinating ligands, and liquid solutions. For fluorescent quantum dots, the properties of the surface vastly influence the efficiency of light emission, stability, and physical interactions, and thus determine their sensitivity and specificity when they are used to detect and image biological molecules. But after more than 30 years of study, the surfaces of quantum dots remain poorly understood and continue to be an important subject of both experimental and theoretical research. In this article, we review the physics and chemistry of quantum dot surfaces and describe approaches to engineer optimal fluorescent probes for applications in biomolecular imaging and sensing. We describe the structure and electronic properties of crystalline facets, the chemistry of ligand coordination, and the impact of ligands on optical properties. We further describe recent advances in compact coatings that have significantly improved their properties by providing small hydrodynamic size, high stability and fluorescence efficiency, and minimal nonspecific interactions with cells and biological molecules. While major progress has been made in both basic and applied research, many questions remain in the chemistry and physics of quantum dot surfaces that have hindered key breakthroughs to fully optimize their properties. PMID:28344357

An improved yeast transformation method for the generation of very large human antibody libraries.

PubMed

Benatuil, Lorenzo; Perez, Jennifer M; Belk, Jonathan; Hsieh, Chung-Ming

2010-04-01

Antibody library selection by yeast display technology is an efficient and highly sensitive method to identify binders to target antigens. This powerful selection tool, however, is often hampered by the typically modest size of yeast libraries (approximately 10(7)) due to the limited yeast transformation efficiency, and the full potential of the yeast display technology for antibody discovery and engineering can only be realized if it can be coupled with a mean to generate very large yeast libraries. We describe here a yeast transformation method by electroporation that allows for the efficient generation of large antibody libraries up to 10(10) in size. Multiple components and conditions including CaCl(2), MgCl(2), sucrose, sorbitol, lithium acetate, dithiothreitol, electroporation voltage, DNA input and cell volume have been tested to identify the best combination. By applying this developed protocol, we have constructed a 1.4 x 10(10) human spleen antibody library essentially in 1 day with a transformation efficiency of 1-1.5 x 10(8) transformants/microg vector DNA. Taken together, we have developed a highly efficient yeast transformation method that enables the generation of very large and productive human antibody libraries for antibody discovery, and we are now routinely making 10(9) libraries in a day for antibody engineering purposes.

Dual-Mission Large Aircraft Feasibility Study and Aerodynamic Investigation

NASA Technical Reports Server (NTRS)

Mavris, Dimitri

1997-01-01

A Dual-Mission Large Aircraft, or DMLA, represents the possibility of a single aircraft capable of fulfilling both a Global Reach Aircraft (GRA) and Very Large Transport (VLT) roles. The DMLA, by combining the GRA and VLT into a single new aircraft, could possibly lower the aircraft manufacturer's production costs through the resulting increase in production quantity. This translates into lower aircraft acquisition costs, a primary concern for both the Air Force and commercial airlines. This report outlines the first steps taken in this study, namely the assessment of technical and economic feasibility of the DMLA concept. In the course of this project, specialized GRA and VLT aircraft were sized for their respective missions, using baseline conventional (i.e., lacking advanced enabling technologies) aircraft models from previous work for the Air Force's Wright Laboratory and NASA-Langley. DMLA baseline aircraft were then also developed, by first sizing the aircraft for the more critical of the two missions and then analyzing the aircraft's performance over the other mission. The resulting aircraft performance values were then compared to assess technical feasibility. Finally, the life-cycle costs of each aircraft (GRA, VLT, and DMLA) were analyzed to quantify economic feasibility. These steps were applied to both a two-engine aircraft set, and a four-engine aircraft set.

UAF Space Systems Engineering Program: Engaging Students through an Apprenticeship Model

NASA Astrophysics Data System (ADS)

Thorsen, D.

2017-12-01

Learning by doing has been the mantra of engineering education for decades, however, the constraints of semester length courses limits the types and size of experiences that can be offered to students. The Space Systems Engineering Program (SSEP) at the University of Alaska Fairbanks provides interdisciplinary engineering and science students with hands-on experience in all aspects of space systems engineering through a design, build, launch paradigm applied to balloon and rocket payloads and small satellites. The program is structured using an apprenticeship model such that students, freshmen through graduate, can participate in multi-year projects thereby gaining experiences appropriate to their level in college. Students enter the lab in a trainee position and receive training on lab processes and design software. Depending on the student's interests they learn how to use specific lab equipment and software design tools. Trainees provide support engineering under guidance of an upper classman. As the students' progress in their degree program and gain more expertise, they typically become part of a specific subsystem team, where they receive additional training in developing design documents and in writing requirements and test documents, and direct their efforts to meeting specific objectives. By the time the student reaches their senior year, they have acquired the leadership role for a specific subsystem and/or a general leadership role in the lab. If students stay to pursue graduate degrees, they assume the responsibility of training and mentoring other undergraduates in their areas of expertise. Throughout the program upper class students mentor the newer students. The Space Systems Engineering Program strives to reinforce a student's degree program through these large scale projects that place engineering in context.

Statistical physics studies of multilayer adsorption isotherm in food materials and pore size distribution

NASA Astrophysics Data System (ADS)

Aouaini, F.; Knani, S.; Ben Yahia, M.; Ben Lamine, A.

2015-08-01

Water sorption isotherms of foodstuffs are very important in different areas of food science engineering such as for design, modeling and optimization of many processes. The equilibrium moisture content is an important parameter in models used to predict changes in the moisture content of a product during storage. A formulation of multilayer model with two energy levels was based on statistical physics and theoretical considerations. Thanks to the grand canonical ensemble in statistical physics. Some physicochemical parameters related to the adsorption process were introduced in the analytical model expression. The data tabulated in literature of water adsorption at different temperatures on: chickpea seeds, lentil seeds, potato and on green peppers were described applying the most popular models applied in food science. We also extend the study to the newest proposed model. It is concluded that among studied models the proposed model seems to be the best for description of data in the whole range of relative humidity. By using our model, we were able to determine the thermodynamic functions. The measurement of desorption isotherms, in particular a gas over a solid porous, allows access to the distribution of pore size PSD.

An Option in Applied Microbiology.

ERIC Educational Resources Information Center

Lee, William E., III

1988-01-01

Describes a program option for undergraduate chemical engineering students interested in biotechnology. Discusses how this program is deployed at the University of Southern Florida. Lists courses which apply to this program. Discusses the goals of teaching applied microbiology to engineering majors. (CW)

Facilitation of University Technology Transfer Through a Cooperative Service-University-Industry Program.

DTIC Science & Technology

1997-02-01

through technology transfer centers for applied engineering training and consulting, and second, in assisting and expanding university technology...both the services and industry with an applied engineering program and the training for new engineers and researchers, (2) serve as an information

Engine Data Interpretation System (EDIS)

NASA Technical Reports Server (NTRS)

Cost, Thomas L.; Hofmann, Martin O.

1990-01-01

A prototype of an expert system was developed which applies qualitative or model-based reasoning to the task of post-test analysis and diagnosis of data resulting from a rocket engine firing. A combined component-based and process theory approach is adopted as the basis for system modeling. Such an approach provides a framework for explaining both normal and deviant system behavior in terms of individual component functionality. The diagnosis function is applied to digitized sensor time-histories generated during engine firings. The generic system is applicable to any liquid rocket engine but was adapted specifically in this work to the Space Shuttle Main Engine (SSME). The system is applied to idealized data resulting from turbomachinery malfunction in the SSME.

International Conference of Applied Science and Technology for Infrastructure Engineering

NASA Astrophysics Data System (ADS)

Elvina Santoso, Shelvy; Hardianto, Ekky

2017-11-01

Preface: International Conference of Applied Science and Technology for Infrastructure Engineering (ICASIE) 2017. The International Conference of Applied Science and Technology for Infrastructure Engineering (ICASIE) 2017 has been scheduled and successfully taken place at Swiss-Bell Inn Hotel, Surabaya, Indonesia, on August 5th 2017 organized by Department of Civil Infrastructure Engineering, Faculty of Vocation, Institut Teknologi Sepuluh Nopember (ITS). This annual event aims to create synergies between government, private sectors; employers; practitioners; and academics. This conference has different theme each year and “MATERIAL FOR INFRASTUCTURE ENGINEERING” will be taken for this year’s main theme. In addition, we also provide a platform for various other sub-theme topic including but not limited to Geopolymer Concrete and Materials Technology, Structural Dynamics, Engineering, and Sustainability, Seismic Design and Control of Structural Vibrations, Innovative and Green Buildings, Project Management, Transportation and Highway Engineering, Geotechnical Engineering, Water Engineering and Resources Management, Surveying and Geospatial Engineering, Coastal Engineering, Geophysics, Energy, Electronic and Mechatronic, Industrial Process, and Data Mining. List of Organizers, Journal Editors, Steering Committee, International Scientific Committee, Chairman, Keynote Speakers are available in this pdf.

Estimation of the vortex length scale and intensity from two-dimensional samples

NASA Technical Reports Server (NTRS)

Reuss, D. L.; Cheng, W. P.

1992-01-01

A method is proposed for estimating flow features that influence flame wrinkling in reciprocating internal combustion engines, where traditional statistical measures of turbulence are suspect. Candidate methods were tested in a computed channel flow where traditional turbulence measures are valid and performance can be rationally evaluated. Two concepts are tested. First, spatial filtering is applied to the two-dimensional velocity distribution and found to reveal structures corresponding to the vorticity field. Decreasing the spatial-frequency cutoff of the filter locally changes the character and size of the flow structures that are revealed by the filter. Second, vortex length scale and intensity is estimated by computing the ensemble-average velocity distribution conditionally sampled on the vorticity peaks. The resulting conditionally sampled 'average vortex' has a peak velocity less than half the rms velocity and a size approximately equal to the two-point-correlation integral-length scale.

Optimizing the coupled effects of Hall-Petch and precipitation strengthening in a Al 0.3 CoCrFeNi high entropy alloy

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

Gwalani, B.; Soni, Vishal; Lee, Michael

2017-05-01

A successful demonstration of applying integrated strengthening using Hall-Petch strengthening (grains size effect) and precipitation strengthening is shown in the fcc based high entropy alloy (HEA) Al0.3CoCrFeNi, leading to quantitative determinations of the Hall-Petch coefficients for both hardness and tensile yield strength, aswell as the enhancements in the yield strength fromtwo distinct types of ordered precipitates, L12 and B2. An excellent combination of yield strength (~490MPa), ultimate tensile strength (~850MPa), and ductility (~45% elongation) was achieved by optimizing and coupling both strengtheningmechanisms, resulting from a refined grain size as well as both L12 and B2 ordered precipitates. This opens upmore » new avenues for the future development of HEAs, with the appropriate balance of properties required for engineering applications.« less

Putting engineering back into protein engineering: bioinformatic approaches to catalyst design.

PubMed

Gustafsson, Claes; Govindarajan, Sridhar; Minshull, Jeremy

2003-08-01

Complex multivariate engineering problems are commonplace and not unique to protein engineering. Mathematical and data-mining tools developed in other fields of engineering have now been applied to analyze sequence-activity relationships of peptides and proteins and to assist in the design of proteins and peptides with specified properties. Decreasing costs of DNA sequencing in conjunction with methods to quickly synthesize statistically representative sets of proteins allow modern heuristic statistics to be applied to protein engineering. This provides an alternative approach to expensive assays or unreliable high-throughput surrogate screens.

Rotorcraft contingency power study

NASA Technical Reports Server (NTRS)

Hirschkron, R.; Haynes, J. F.; Goldstein, D. N.; Davis, R. H.

1984-01-01

Twin helicopter engines are often sized by the power requirement of a safe mission completion after the failure of one of the two engines. This study was undertaken for NASA Lewis by General Electric Co. to evaluate the merits of special design features to provide a 2-1/2 Contingency Power rating, permitting an engine size reduction. The merits of water injection, turbine cooling airflow modulation, throttle push, and a propellant auxiliary power plant were evaluated using military Life Cycle Cost (LCC) and commercial helicopter Direct Operating Cost (DOC) merit factors in a rubber engine and a rubber aircraft scenario.

40 CFR 1045.601 - What compliance provisions apply to these engines?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false What compliance provisions apply to these engines? 1045.601 Section 1045.601 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

40 CFR 1045.601 - What compliance provisions apply to these engines?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false What compliance provisions apply to these engines? 1045.601 Section 1045.601 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

40 CFR 1045.640 - What special provisions apply to branded engines?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false What special provisions apply to branded engines? 1045.640 Section 1045.640 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

40 CFR 1045.640 - What special provisions apply to branded engines?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false What special provisions apply to branded engines? 1045.640 Section 1045.640 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

40 CFR 1045.601 - What compliance provisions apply to these engines?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false What compliance provisions apply to these engines? 1045.601 Section 1045.601 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

40 CFR 1045.601 - What compliance provisions apply to these engines?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false What compliance provisions apply to these engines? 1045.601 Section 1045.601 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

40 CFR 1045.601 - What compliance provisions apply to these engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What compliance provisions apply to these engines? 1045.601 Section 1045.601 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

40 CFR 1045.640 - What special provisions apply to branded engines?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false What special provisions apply to branded engines? 1045.640 Section 1045.640 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

40 CFR 1045.640 - What special provisions apply to branded engines?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false What special provisions apply to branded engines? 1045.640 Section 1045.640 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND...

Facilitation of University Technology Transfer through a Cooperative Army-University-Industry Program,

DTIC Science & Technology

1995-01-01

through Army technology transfer centers for applied engineering training and consulting, and second in assisting and expanding university technology...industry with an applied engineering program and the training for new engineers and researchers, serve as an information resource for both the Army and

Optimization of nanoparticles for cardiovascular tissue engineering.

PubMed

Izadifar, Mohammad; Kelly, Michael E; Haddadi, Azita; Chen, Xiongbiao

2015-06-12

Nano-particulate delivery systems have increasingly been playing important roles in cardiovascular tissue engineering. Properties of nanoparticles (e.g. size, polydispersity, loading capacity, zeta potential, morphology) are essential to system functions. Notably, these characteristics are regulated by fabrication variables, but in a complicated manner. This raises a great need to optimize fabrication process variables to ensure the desired nanoparticle characteristics. This paper presents a comprehensive experimental study on this matter, along with a novel method, the so-called Geno-Neural approach, to analyze, predict and optimize fabrication variables for desired nanoparticle characteristics. Specifically, ovalbumin was used as a protein model of growth factors used in cardiovascular tissue regeneration, and six fabrication variables were examined with regard to their influence on the characteristics of nanoparticles made from high molecular weight poly(lactide-co-glycolide). The six-factor five-level central composite rotatable design was applied to the conduction of experiments, and based on the experimental results, a geno-neural model was developed to determine the optimum fabrication conditions. For desired particle sizes of 150, 200, 250 and 300 nm, respectively, the optimum conditions to achieve the low polydispersity index, higher negative zeta potential and higher loading capacity were identified based on the developed geno-neural model and then evaluated experimentally. The experimental results revealed that the polymer and the external aqueous phase concentrations and their interactions with other fabrication variables were the most significant variables to affect the size, polydispersity index, zeta potential, loading capacity and initial burst release of the nanoparticles, while the electron microscopy images of the nanoparticles showed their spherical geometries with no sign of large pores or cracks on their surfaces. The release study revealed that the onset of the third phase of release can be affected by the polymer concentration. Circular dichroism spectroscopy indicated that ovalbumin structural integrity is preserved during the encapsulation process. Findings from this study would greatly contribute to the design of high molecular weight poly(lactide-co-glycolide) nanoparticles for prolonged release patterns in cardiovascular engineering.

40 CFR 90.706 - Engine sample selection.

Code of Federal Regulations, 2010 CFR

2010-07-01

... = emission test result for an individual engine. x = mean of emission test results of the actual sample. FEL... test with the last test result from the previous model year and then calculate the required sample size.... Test results used to calculate the variables in the following Sample Size Equation must be final...

The Effect of Pixel Size on the Accuracy of Orthophoto Production

NASA Astrophysics Data System (ADS)

Kulur, S.; Yildiz, F.; Selcuk, O.; Yildiz, M. A.

2016-06-01

In our country, orthophoto products are used by the public and private sectors for engineering services and infrastructure projects, Orthophotos are particularly preferred due to faster and are more economical production according to vector digital photogrammetric production. Today, digital orthophotos provide an expected accuracy for engineering and infrastructure projects. In this study, the accuracy of orthophotos using pixel sizes with different sampling intervals are tested for the expectations of engineering and infrastructure projects.

Technologies for Energy from Biomass by Direct Combustion, Gasification, and Liquefaction.

DTIC Science & Technology

1981-05-01

1980 1982 1984 Development Alberta Industrial Dev. X American Fyr. Feeder X Andco, Inc. X Applied Engineering Co., Inc. X Biomass Corp. X Bio-Solar x...Feeder ANDCO, Inc. Applied Engineering Company Biomass Corporation Bio-Solar Research and Development Corporation Combustion Power Company, Inc. Davy...Andco. Inc. X Applied Engineering Co., Inc. X Biomass Corp. X , Big-Solar .X I Combustion Power .. XI Davy Powergas X j Dekalb Acresearch, Inc.- x Duvant

Marine Engine-Exhaust Emissions Test Cell

DOT National Transportation Integrated Search

1974-11-01

A marine engine exhaust emissions test cell for boat-size diesel engines (approx. 200 hp) and outboard engines was constructed as part of a project sponsored by the United States Coast Guard for the monitoring and control of emissions from marine sou...

40 CFR 89.1009 - What special provisions apply to branded engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false What special provisions apply to branded engines? 89.1009 Section 89.1009 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... branded engines? A manufacturer identifying the name and trademark of another company on the emission...

40 CFR 1039.625 - What requirements apply under the program for equipment-manufacturer flexibility?

Code of Federal Regulations, 2012 CFR

2012-07-01

... NONROAD COMPRESSION-IGNITION ENGINES Special Compliance Provisions § 1039.625 What requirements apply... manufacturers to produce equipment with engines that are subject to less stringent emission standards after the... such equipment without manufacturing it. Engines and equipment you produce under this section are...

40 CFR 1039.625 - What requirements apply under the program for equipment-manufacturer flexibility?

Code of Federal Regulations, 2013 CFR

2013-07-01

... NONROAD COMPRESSION-IGNITION ENGINES Special Compliance Provisions § 1039.625 What requirements apply... manufacturers to produce equipment with engines that are subject to less stringent emission standards after the... such equipment without manufacturing it. Engines and equipment you produce under this section are...

46 CFR 162.161-1 - Scope.

Code of Federal Regulations, 2014 CFR

2014-10-01

... APPROVAL ENGINEERING EQUIPMENT Fixed Clean Agent Fire Extinguishing Systems § 162.161-1 Scope. (a) This subpart applies to each engineered fixed fire extinguishing system using a halocarbon or an inert gas as an agent. It does not apply to pre-engineered systems. (b) Each system must be designed for...

46 CFR 162.161-1 - Scope.

Code of Federal Regulations, 2013 CFR

2013-10-01

... APPROVAL ENGINEERING EQUIPMENT Fixed Clean Agent Fire Extinguishing Systems § 162.161-1 Scope. (a) This subpart applies to each engineered fixed fire extinguishing system using a halocarbon or an inert gas as an agent. It does not apply to pre-engineered systems. (b) Each system must be designed for...

46 CFR 162.161-1 - Scope.

Code of Federal Regulations, 2012 CFR

2012-10-01

... APPROVAL ENGINEERING EQUIPMENT Fixed Clean Agent Fire Extinguishing Systems § 162.161-1 Scope. (a) This subpart applies to each engineered fixed fire extinguishing system using a halocarbon or an inert gas as an agent. It does not apply to pre-engineered systems. (b) Each system must be designed for...

Garrett Electric Boosting Systems (EBS) Program

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

Steve Arnold; Craig Balis; Pierre Barthelet

2005-03-31

Turbo diesel engine use in passenger cars in Europe has resulted in 30-50% improvement in fuel economy. Diesel engine application is particularly suitable for US because of vehicle size and duty cycle patterns. Adopting this technology for use in the US presents two issues--emissions and driveability. Emissions reduction technology is being well addressed with advanced turbocharging, fuel injection and catalytic aftertreatment systems One way to address driveability is to eliminate turbo lag and increase low speed torque. Electrically assisted turbocharging concepts incorporated in e-Turbo{trademark} designs do both The purpose of this project is to design and develop an electrically assistedmore » turbocharger, e-Turbo{trademark}, for diesel engine use in the US. In this report, early design and development of electrical assist technology is described together with issues and potential benefits. In this early phase a mathematical model was developed and verified. The model was used in a sensitivity study. The results of the sensitivity study together with the design and test of first generation hardware was fed into second generation designs. In order to fully realize the benefits of electrical assist technology it was necessary to expand the scope of work to include technology on the compressor side as well as electronic controls concepts. The results of the expanded scope of work are also reported here. In the first instance, designs and hardware were developed for a small engine to quantify and demonstrate benefits. The turbo size was such that it could be applied in a bi-turbo configuration to an SUV sized V engine. Mathematical simulation was used to quantify the possible benefits in an SUV application. It is shown that low speed torque can be increased to get the high performance expected in US, automatic transmission vehicles. It is also shown that e-Turbo{trademark} can be used to generate modest amounts of electrical power and supplement the alternator under most load-speed conditions. It is shown that a single (large) e-Turbo{trademark} consumes slightly less electrical power for the same steady state torque shaping than a bi-Turbo configuration. However, the transient response of a bi-Turbo configuration is slightly better. It was shown that in order to make full use of additional capabilities of e-Turbo{trademark} wide compressor flow range is required. Variable geometry compressor (VGC) technology developed under a separate project was evaluated for incorporation into e-Turbo{trademark} designs. It was shown that the combination of these two technologies enables very high torque at low engine speeds. Designs and hardware combining VGC and e-Turbo{trademark} are to be developed in a future project. There is concern about high power demands (even though momentary) of e-Turbo{trademark}. Reducing the inertia of the turbocharger can reduce power demand and increase battery life. Low inertia turbocharger technology called IBT developed under a separate project was evaluated for synergy with e-Turbo{trademark} designs. It was concluded that inertial reduction provided by IBT is very beneficial for e-Turbo{trademark}. Designs and hardware combining IBT and e-Turbo{trademark} are to be developed in a future project. e-Turbo{trademark} provides several additional flexibilities including exhaust gas recirculation (EGR) for emissions reduction with minimum fuel economy penalty and exhaust temperature control for aftertreatment. In integrated multi-parameter control system is needed to realize the full potential of e-Turbo{trademark} performance. Honeywell expertise in process control systems involving hundreds of sensors and actuators was applied to demonstrate the potential benefits of multi-parameter, model based control systems.« less

Evaluation of innovative rocket engines for single-stage earth-to-orbit vehicles

NASA Astrophysics Data System (ADS)

Manski, Detlef; Martin, James A.

1988-07-01

Computer models of rocket engines and single-stage-to-orbit vehicles that were developed by the authors at DFVLR and NASA have been combined. The resulting code consists of engine mass, performance, trajectory and vehicle sizing models. The engine mass model includes equations for each subsystem and describes their dependences on various propulsion parameters. The engine performance model consists of multidimensional sets of theoretical propulsion properties and a complete thermodynamic analysis of the engine cycle. The vehicle analyses include an optimized trajectory analysis, mass estimation, and vehicle sizing. A vertical-takeoff, horizontal-landing, single-stage, winged, manned, fully reusable vehicle with a payload capability of 13.6 Mg (30,000 lb) to low earth orbit was selected. Hydrogen, methane, propane, and dual-fuel engines were studied with staged-combustion, gas-generator, dual bell, and the dual-expander cycles. Mixture ratio, chamber pressure, nozzle exit pressure liftoff acceleration, and dual fuel propulsive parameters were optimized.

Evaluation of innovative rocket engines for single-stage earth-to-orbit vehicles

NASA Technical Reports Server (NTRS)

Manski, Detlef; Martin, James A.

1988-01-01

Computer models of rocket engines and single-stage-to-orbit vehicles that were developed by the authors at DFVLR and NASA have been combined. The resulting code consists of engine mass, performance, trajectory and vehicle sizing models. The engine mass model includes equations for each subsystem and describes their dependences on various propulsion parameters. The engine performance model consists of multidimensional sets of theoretical propulsion properties and a complete thermodynamic analysis of the engine cycle. The vehicle analyses include an optimized trajectory analysis, mass estimation, and vehicle sizing. A vertical-takeoff, horizontal-landing, single-stage, winged, manned, fully reusable vehicle with a payload capability of 13.6 Mg (30,000 lb) to low earth orbit was selected. Hydrogen, methane, propane, and dual-fuel engines were studied with staged-combustion, gas-generator, dual bell, and the dual-expander cycles. Mixture ratio, chamber pressure, nozzle exit pressure liftoff acceleration, and dual fuel propulsive parameters were optimized.

Engine lubrication circuit including two pumps

DOEpatents

Lane, William H.

2006-10-03

A lubrication pump coupled to the engine is sized such that the it can supply the engine with a predetermined flow volume as soon as the engine reaches a peak torque engine speed. In engines that operate predominately at speeds above the peak torque engine speed, the lubrication pump is often producing lubrication fluid in excess of the predetermined flow volume that is bypassed back to a lubrication fluid source. This arguably results in wasted power. In order to more efficiently lubricate an engine, a lubrication circuit includes a lubrication pump and a variable delivery pump. The lubrication pump is operably coupled to the engine, and the variable delivery pump is in communication with a pump output controller that is operable to vary a lubrication fluid output from the variable delivery pump as a function of at least one of engine speed and lubrication flow volume or system pressure. Thus, the lubrication pump can be sized to produce the predetermined flow volume at a speed range at which the engine predominately operates while the variable delivery pump can supplement lubrication fluid delivery from the lubrication pump at engine speeds below the predominant engine speed range.

A Keyboard for Underwater Performance Assessment Battery Testing

DTIC Science & Technology

1990-11-08

Applied Engineering . This four button underwater keyboard uses only a small portion of the boards capacity. The cable is connected to the I/O 32 board via a...H.O., by Applied Engineering ) require special programming to work with the IO 32 board. If the boards are accessed directly from Apple Basic with the... Applied Engineering , 1988) is presented in the Appendix. This program will work with either the enhanced or the unenhanced version of the Apple lie. 6

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES

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

Victor W. Wong; Tian Tian; Grant Smedley

2004-09-30

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston/ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and emissions. An iterative process of simulation, experimentation and analysis, are being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston/ring dynamic and friction models have been developed and applied that illustrated the fundamental relationships between design parameters and friction losses. Various low-friction strategies and ring-design concepts have been explored, and engine experiments have been done on a full-scalemore » Waukesha VGF F18 in-line 6 cylinder power generation engine rated at 370 kW at 1800 rpm. Current accomplishments include designing and testing ring-packs using a subtle top-compression-ring profile (skewed barrel design), lowering the tension of the oil-control ring, employing a negative twist to the scraper ring to control oil consumption. Initial test data indicate that piston ring-pack friction was reduced by 35% by lowering the oil-control ring tension alone, which corresponds to a 1.5% improvement in fuel efficiency. Although small in magnitude, this improvement represents a first step towards anticipated aggregate improvements from other strategies. Other ring-pack design strategies to lower friction have been identified, including reduced axial distance between the top two rings, tilted top-ring groove. Some of these configurations have been tested and some await further evaluation. Colorado State University performed the tests and Waukesha Engine Dresser, Inc. provided technical support. Key elements of the continuing work include optimizing the engine piston design, application of surface and material developments in conjunction with improved lubricant properties, system modeling and analysis, and continued technology demonstration in an actual full-sized reciprocating natural-gas engine.« less

Motor-Reducer Sizing through a MATLAB-Based Graphical Technique

ERIC Educational Resources Information Center

Giberti, H.; Cinquemani, S.

2012-01-01

The design of the drive system for an automatic machine and its correct sizing is a very important competence for an electrical or mechatronic engineer. This requires knowledge that crosses the fields of electrical engineering, electronics and mechanics, as well as the skill to choose commercial components based upon their technical documentation.…

A Matter of Size: Flipping Library Instruction in Various Engineering Classrooms

ERIC Educational Resources Information Center

Maddison, Tasha

2015-01-01

This case study explores the use of flipped teaching in three different undergraduate engineering courses, discussing the advantages and disadvantages of class size and how it affects the delivery of information literacy instruction as observed through student engagement and the perceived helpfulness of the instruction. A flipped classroom was…

Surface-enhanced Raman spectroscopy on laser-engineered ruthenium dye-functionalized nanoporous gold

NASA Astrophysics Data System (ADS)

Schade, Lina; Franzka, Steffen; Biener, Monika; Biener, Jürgen; Hartmann, Nils

2016-06-01

Photothermal processing of nanoporous gold with a microfocused continuous-wave laser at λ = 532 nm provides a facile means in order engineer the pore and ligament size of nanoporous gold. In this report we take advantage of this approach in order to investigate the size-dependence of enhancement effects in surface-enhanced Raman spectroscopy (SERS). Surface structures with laterally varying pore sizes from 25 nm to ≥200 nm are characterized using scanning electron microscopy and then functionalized with N719, a commercial ruthenium complex, which is widely used in dye-sensitized solar cells. Raman spectroscopy reveals the characteristic spectral features of N719. Peak intensities strongly depend on the pore size. Highest intensities are observed on the native support, i.e. on nanoporous gold with pore sizes around 25 nm. These results demonstrate the particular perspectives of laser-fabricated nanoporous gold structures in fundamental SERS studies. In particular, it is emphasized that laser-engineered porous gold substrates represent a very well defined platform in order to study size-dependent effects with high reproducibility and precision and resolve conflicting results in previous studies.

A silk-based scaffold platform with tunable architecture for engineering critically-sized tissue constructs.

PubMed

Wray, Lindsay S; Rnjak-Kovacina, Jelena; Mandal, Biman B; Schmidt, Daniel F; Gil, Eun Seok; Kaplan, David L

2012-12-01

In the field of tissue engineering and regenerative medicine there is significant unmet need for critically-sized, fully degradable biomaterial scaffold systems with tunable properties for optimizing tissue formation in vitro and tissue regeneration in vivo. To address this need, we have developed a silk-based scaffold platform that has tunable material properties, including localized and bioactive functionalization, degradation rate, and mechanical properties and that provides arrays of linear hollow channels for delivery of oxygen and nutrients throughout the scaffold bulk. The scaffolds can be assembled with dimensions that range from millimeters to centimeters, addressing the need for a critically-sized platform for tissue formation. We demonstrate that the hollow channel arrays support localized and confluent endothelialization. This new platform offers a unique and versatile tool for engineering 'tailored' scaffolds for a range of tissue engineering and regenerative medicine needs. Copyright © 2012 Elsevier Ltd. All rights reserved.

Engineering the architectural diversity of heterogeneous metallic nanocrystals.

PubMed

Yu, Yue; Zhang, Qingbo; Xie, Jianping; Lee, Jim Yang

2013-01-01

Similar to molecular engineering where structural diversity is used to create more property variations for application explorations, the architectural engineering of heterogeneous metallic nanocrystals (HMNCs) can likewise increase the versatility of metallic nanocrystals (NCs). Here we present a synthesis strategy capable of engineering the architectural diversity of HMNCs through rational and independent programming of every architecture-determining element, that is, the shape and size of the component NCs and their spatial arrangement. The strategy is based on the galvanic replacement reaction of a self-sustaining layer formed by underpotential deposition on a polyhedral NC. The selective deposition of satellite NCs on specific site of the central NC is realized by creating a geometry-dependent heterogeneous electron distribution. This site-selective deposition approach is applicable to central NCs in various polyhedral shapes and sizes. The satellite NCs can further develop their own shape and size through crystal growth kinetics control.

Nanotechnology Investigated for Future Gelled and Metallized Gelled Fuels

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan A.

2003-01-01

The objective of this research is to create combustion data for gelled and metallized gelled fuels using unique nanometer-sized gellant particles and/or nanometer-sized aluminum particles. Researchers at the NASA Glenn Research Center are formulating the fuels for both gas turbine and pulsed detonation engines. We intend to demonstrate metallized gelled fuel ignition characteristics for pulse detonation engines with JP/aluminum fuel and for gas turbine engines with gelled JP, propane, and methane fuel. The fuels to be created are revolutionary as they will deliver the highest theoretically maximum performance of gelled and metallized gelled fuels. Past combustion work has used micrometer-sized particles, which have limited the combustion performance of gelled and metallized gelled fuels. The new fuel used nanometer-sized aluminum oxide particles, which reduce the losses due to mismatch in the gas and solid phases in the exhaust. Gelled fuels provide higher density, added safety, reduced fuel slosh, reduced leakage, and increased exhaust velocity. Altogether, these benefits reduce the overall size and mass of the vehicle, increasing its flexibility.

Specialized data analysis for the Space Shuttle Main Engine and diagnostic evaluation of advanced propulsion system components

NASA Technical Reports Server (NTRS)

1993-01-01

The Marshall Space Flight Center is responsible for the development and management of advanced launch vehicle propulsion systems, including the Space Shuttle Main Engine (SSME), which is presently operational, and the Space Transportation Main Engine (STME) under development. The SSME's provide high performance within stringent constraints on size, weight, and reliability. Based on operational experience, continuous design improvement is in progress to enhance system durability and reliability. Specialized data analysis and interpretation is required in support of SSME and advanced propulsion system diagnostic evaluations. Comprehensive evaluation of the dynamic measurements obtained from test and flight operations is necessary to provide timely assessment of the vibrational characteristics indicating the operational status of turbomachinery and other critical engine components. Efficient performance of this effort is critical due to the significant impact of dynamic evaluation results on ground test and launch schedules, and requires direct familiarity with SSME and derivative systems, test data acquisition, and diagnostic software. Detailed analysis and evaluation of dynamic measurements obtained during SSME and advanced system ground test and flight operations was performed including analytical/statistical assessment of component dynamic behavior, and the development and implementation of analytical/statistical models to efficiently define nominal component dynamic characteristics, detect anomalous behavior, and assess machinery operational condition. In addition, the SSME and J-2 data will be applied to develop vibroacoustic environments for advanced propulsion system components, as required. This study will provide timely assessment of engine component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. This contract will be performed through accomplishment of negotiated task orders.

An Assessment of Research-Doctorate Programs in the United States: Engineering.

ERIC Educational Resources Information Center

Jones, Lyle V., Ed.; And Others

The quality of doctoral-level chemical engineering (N=79), civil engineering (N=74), electrical engineering (N=91), and mechanical engineering (N=82) programs at United States universities was assessed, using 16 measures. These measures focused on variables related to: (1) program size; (2) characteristics of graduates; (3) reputational factors…

Evaluation of an Audience Response System in Library Orientations for Engineering Students

ERIC Educational Resources Information Center

Brush, Denise A.

2010-01-01

While interactive hands-on instruction is usually considered the best approach for engineering students for both their academic courses and for library instruction, the size of the engineering student population compared to the number of instructors and the available classroom space means that engineering librarians, like engineering faculty, may…

Automotive Stirling Engine Development Program

NASA Technical Reports Server (NTRS)

Nightingale, N.; Ernst, W.; Richey, A.; Simetkosky, M.; Antonelli, M. (Editor)

1982-01-01

Activities performed on Mod I engine testing and test results; the manufacture, assembly, and test of a Mod I engine in the United States; design initiation of the Mod I-A engine system; transient performance testing; Stirling reference engine manufacturing and reduced size studies; components and subsystems; and the study and test of low cost alloys are summarized.

Automotive Stirling engine development program

NASA Technical Reports Server (NTRS)

Ernst, W.; Piller, S.; Richey, A.; Simetkosky, M.; Antonelli, M. (Editor)

1982-01-01

Activities performed on Mod I engine testing and test results, progress in manufacturing, assembling and testing of a Mod I engine in the United States, P40 Stirling engine dynamometer and multifuels testing, analog/digital controls system testing, Stirling reference engine manufacturing and reduced size studies, components and subsystems, and computer code development are summarized.

Developing a New Industrial Engineering Curriculum Using a Systems Engineering Approach

ERIC Educational Resources Information Center

Buyurgan, Nebil; Kiassat, Corey

2017-01-01

This paper reports on the development of an engineering curriculum for a new industrial engineering programme at a medium-sized private university in the northeast United States. A systems engineering process has been followed to design and develop the new curriculum. Considering the programme curriculum as a system, first the stakeholders have…

Geotechnical characterization of mined clay from Appalachian Ohio: challenges and implications for the clay mining industry.

PubMed

Moran, Anthony R; Hettiarachchi, Hiroshan

2011-07-01

Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL) in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling.

Geotechnical Characterization of Mined Clay from Appalachian Ohio: Challenges and Implications for the Clay Mining Industry

PubMed Central

Moran, Anthony R.; Hettiarachchi, Hiroshan

2011-01-01

Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL) in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling. PMID:21845150

Performance of Diffusion Aluminide Coatings Applied on Alloy CF8C-Plus at 800oC

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

Kumar, Deepak; Dryepondt, Sebastien N; Zhang, Ying

2012-01-01

High performance cast stainless steel, CF8C-Plus, is a low cost alloy with prospective applications ranging from covers and casings of small and medium size gas turbines to turbocharger housing and manifolds in internal combustion engines. Diffusion aluminide coatings were applied on this alloy as a potential strategy for improved oxidation resistance, particularly in wet air and steam. In this paper the performance of the aluminide coatings evaluated by cyclic oxidation experiments in air containing 10 vol.% H2O at 800 C and conventional tension-compression low-cycle-fatigue tests in air at 800 C with a strain range of 0.5% is presented. The resultsmore » show that specimens coated by a chemical vapor deposition process provide better oxidation resistance than those coated by an Al-slurry coating process. The application of a coating by pack cementation reduced the fatigue life by 15%.« less

Scalable Methods for Eulerian-Lagrangian Simulation Applied to Compressible Multiphase Flows

NASA Astrophysics Data System (ADS)

Zwick, David; Hackl, Jason; Balachandar, S.

2017-11-01

Multiphase flows can be found in countless areas of physics and engineering. Many of these flows can be classified as dispersed two-phase flows, meaning that there are solid particles dispersed in a continuous fluid phase. A common technique for simulating such flow is the Eulerian-Lagrangian method. While useful, this method can suffer from scaling issues on larger problem sizes that are typical of many realistic geometries. Here we present scalable techniques for Eulerian-Lagrangian simulations and apply it to the simulation of a particle bed subjected to expansion waves in a shock tube. The results show that the methods presented here are viable for simulation of larger problems on modern supercomputers. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1315138. This work was supported in part by the U.S. Department of Energy under Contract No. DE-NA0002378.

40 CFR 1039.625 - What requirements apply under the program for equipment-manufacturer flexibility?

Code of Federal Regulations, 2014 CFR

2014-07-01

... differences that justify your request. (vi) Describe your efforts to find and use other compliant engines, or... NONROAD COMPRESSION-IGNITION ENGINES Special Compliance Provisions § 1039.625 What requirements apply... manufacturers to produce equipment with engines that are subject to less stringent emission standards after the...

40 CFR 86.1930 - What special provisions apply from 2005 through 2010?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86.1930 What special provisions apply from 2005 through 2010? (a) We may direct you to test engines under this subpart for...

40 CFR 86.1930 - What special provisions apply from 2005 through 2010?

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86.1930 What special provisions apply from 2005 through 2010? (a) We may direct you to test engines under this subpart for...

40 CFR 86.1930 - What special provisions apply from 2005 through 2010?

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86.1930 What special provisions apply from 2005 through 2010? (a) We may direct you to test engines under this subpart for...

40 CFR 1068.510 - How do I prepare and apply my remedial plan?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) AIR POLLUTION CONTROLS GENERAL COMPLIANCE PROVISIONS FOR ENGINE PROGRAMS Reporting Defects and Recalling Engines/Equipment § 1068.510 How do I prepare and apply my remedial plan? (a) In your remedial plan, describe all of the following: (1) The class or category of engines/equipment to be recalled...

40 CFR 1068.360 - What restrictions apply to assigning a model year to imported engines and equipment?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false What restrictions apply to assigning a model year to imported engines and equipment? 1068.360 Section 1068.360 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS GENERAL COMPLIANCE PROVISIONS FOR ENGINE...

40 CFR 1068.360 - What restrictions apply to assigning a model year to imported engines and equipment?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What restrictions apply to assigning a model year to imported engines and equipment? 1068.360 Section 1068.360 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS GENERAL COMPLIANCE PROVISIONS FOR ENGINE...

Interconnected porous hydroxyapatite ceramics for bone tissue engineering

PubMed Central

Yoshikawa, Hideki; Tamai, Noriyuki; Murase, Tsuyoshi; Myoui, Akira

2008-01-01

Several porous calcium hydroxyapatite (HA) ceramics have been used clinically as bone substitutes, but most of them possessed few interpore connections, resulting in pathological fracture probably due to poor bone formation within the substitute. We recently developed a fully interconnected porous HA ceramic (IP-CHA) by adopting the ‘foam-gel’ technique. The IP-CHA had a three-dimensional structure with spherical pores of uniform size (average 150 μm, porosity 75%), which were interconnected by window-like holes (average diameter 40 μm), and also demonstrated adequate compression strength (10–12 MPa). In animal experiments, the IP-CHA showed superior osteoconduction, with the majority of pores filled with newly formed bone. The interconnected porous structure facilitates bone tissue engineering by allowing the introduction of mesenchymal cells, osteotropic agents such as bone morphogenetic protein or vasculature into the pores. Clinically, we have applied the IP-CHA to treat various bony defects in orthopaedic surgery, and radiographic examinations demonstrated that grafted IP-CHA gained radiopacity more quickly than the synthetic HA in clinical use previously. We review the accumulated data on bone tissue engineering using the novel scaffold and on clinical application in the orthopaedic field. PMID:19106069

Nanoceramics on osteoblast proliferation and differentiation in bone tissue engineering.

PubMed

Sethu, Sai Nievethitha; Namashivayam, Subhapradha; Devendran, Saravanan; Nagarajan, Selvamurugan; Tsai, Wei-Bor; Narashiman, Srinivasan; Ramachandran, Murugesan; Ambigapathi, Moorthi

2017-05-01

Bone, a highly dynamic connective tissue, consist of a bioorganic phase comprising osteogenic cells and proteins which lies over an inorganic phase predominantly made of CaPO 4 (biological apatite). Injury to bone can be due to mechanical, metabolic or inflammatory agents also owing pathological conditions like fractures, osteomyelitis, osteolysis or cysts may arise in enameloid, chondroid, cementum, or chondroid bone which forms the intermediate tissues of the body. Bone tissue engineering (BTE) applies bioactive scaffolds, host cells and osteogenic signals for restoring damaged or diseased tissues. Various bioceramics used in BTE can be bioactive (like glass ceramics and hydroxyapatite bioactive glass), bioresorbable (like tricalcium phosphates) or bioinert (like zirconia and alumina). Limiting the size of these materials to nano-scale has resulted in a higher surface area to volume ratio thereby improving multi-functionality, solubility, surface catalytic activity, high heat and electrical conductivity. Nanoceramics have been found to induce osteoconduction, osteointegration, osteogenesis and osteoinduction. The present review aims at summarizing the interactions of nanoceramics and osteoblast/stem cells for promoting the proliferation and differentiation of the osteoblast cells by nanoceramics as superior bone substitutes in bone tissue engineering applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Noyce SWARMS Scholars and Two Professional Development Models (LASSI and RAMPED): Summer 2015, 2016, and 2017

NASA Astrophysics Data System (ADS)

Burrows, Andrea C.; Myers, Adam D.; Borowczak, Mike

2018-06-01

This poster showcases an astronomy professional development (PD) for 41 K-12 teachers. The project was entitled Launching Astronomy Standards and STEM Integration (LASSI). A project description (activities in the 18 months - Summer 2015 and 2016) for the astronomy, authentic science, and pre-service teacher opportunities is included. The PD team utilized real-world problems, participant-generated questions, science instruments, technology, evidence, communication, dissemination, and collaboration in the LASSI PD model. Computer science was a feature of the PD and the K-12 teacher participants showcased various methods of its use. Embracing an engineering process with an authentic astronomy PD allowed participants to make connections to current topics and create shareable projects. The PD team highlights teacher work from LASSI entitled - A Model for Determining Size of Objects in an Artificial Solar System. The Sustaining Wyoming's Advancing Reach in Mathematics and Science (SWARMS) Scholars (NSF Noyce funded) interacted with and used the materials from the LASSI PD. The poster highlights PD use from the LASSI participants and SWARMS Scholars as well as explains lessons learned to date as a follow-up PD Robotics, Applied Mathematics, Physics, and Engineering Design (RAMPED) was implemented in Summer 2017 and carried methods from LASSI. The LASSI and RAMPED PD teams included faculty from the College of Education, College of Engineering and Applied Science, College of Arts and Sciences, graduate students, and the teachers themselves. The PD teams created a website with these and other PD materials - UWpd.org - for others to view and change to meet their needs.

Establishment of a preclinical ovine model for tibial segmental bone defect repair by applying bone tissue engineering strategies.

PubMed

Reichert, Johannes C; Epari, Devakara R; Wullschleger, Martin E; Saifzadeh, Siamak; Steck, Roland; Lienau, Jasmin; Sommerville, Scott; Dickinson, Ian C; Schütz, Michael A; Duda, Georg N; Hutmacher, Dietmar W

2010-02-01

Currently, well-established clinical therapeutic approaches for bone reconstruction are restricted to the transplantation of autografts and allografts, and the implantation of metal devices or ceramic-based implants to assist bone regeneration. Bone grafts possess osteoconductive and osteoinductive properties; however, they are limited in access and availability and associated with donor-site morbidity, hemorrhage, risk of infection, insufficient transplant integration, graft devitalization, and subsequent resorption resulting in decreased mechanical stability. As a result, recent research focuses on the development of alternative therapeutic concepts. The field of tissue engineering has emerged as an important approach to bone regeneration. However, bench-to-bedside translations are still infrequent as the process toward approval by regulatory bodies is protracted and costly, requiring both comprehensive in vitro and in vivo studies. The subsequent gap between research and clinical translation, hence, commercialization, is referred to as the "Valley of Death" and describes a large number of projects and/or ventures that are ceased due to a lack of funding during the transition from product/technology development to regulatory approval and subsequently commercialization. One of the greatest difficulties in bridging the Valley of Death is to develop good manufacturing processes and scalable designs and to apply these in preclinical studies. In this article, we describe part of the rationale and road map of how our multidisciplinary research team has approached the first steps to translate orthopedic bone engineering from bench to bedside by establishing a preclinical ovine critical-sized tibial segmental bone defect model, and we discuss our preliminary data relating to this decisive step.

The Effect of Altitude Conditions on the Particle Emissions of a J85-GE-5L Turbojet Engine

NASA Technical Reports Server (NTRS)

Rickey, June Elizabeth

1995-01-01

Particles from a J85-GE-5L turbojet engine were measured over a range of engine speeds at simulated altitude conditions ranging from near sea level to 45,000 ft and at flight Mach numbers of 0.5 and 0.8. Samples were collected from the engine by using a specially designed probe positioned several inches behind the exhaust nozzle. A differential mobility particle sizing system was used to determine particle size. Particle data measured at near sea-level conditions were compared with Navy Aircraft Environmental Support Office (AESO) particle data taken from a GE-J85-4A engine at a sea-level static condition. Particle data from the J85 engine were also compared with particle data from a J85 combustor at three different simulated altitudes.

Interference-free Micro/nanoparticle Cell Engineering by Use of High-Throughput Microfluidic Separation.

PubMed

Yeo, David C; Wiraja, Christian; Zhou, Yingying; Tay, Hui Min; Xu, Chenjie; Hou, Han Wei

2015-09-23

Engineering cells with active-ingredient-loaded micro/nanoparticles is becoming increasingly popular for imaging and therapeutic applications. A critical yet inadequately addressed issue during its implementation concerns the significant number of particles that remain unbound following the engineering process, which inadvertently generate signals and impart transformative effects onto neighboring nontarget cells. Here we demonstrate that those unbound micro/nanoparticles remaining in solution can be efficiently separated from the particle-labeled cells by implementing a fast, continuous, and high-throughput Dean flow fractionation (DFF) microfluidic device. As proof-of-concept, we applied the DFF microfluidic device for buffer exchange to sort labeled suspension cells (THP-1) from unbound fluorescent dye and dye-loaded micro/nanoparticles. Compared to conventional centrifugation, the depletion efficiency of free dyes or particles was improved 20-fold and the mislabeling of nontarget bystander cells by free particles was minimized. The microfluidic device was adapted to further accommodate heterogeneous-sized mesenchymal stem cells (MSCs). Complete removal of unbound nanoparticles using DFF led to the usage of engineered MSCs without exerting off-target transformative effects on the functional properties of neighboring endothelial cells. Apart from its effectiveness in removing free particles, this strategy is also efficient and scalable. It could continuously process cell solutions with concentrations up to 10(7) cells·mL(-1) (cell densities commonly encountered during cell therapy) without observable loss of performance. Successful implementation of this technology is expected to pave the way for interference-free clinical application of micro/nanoparticle engineered cells.

Number size distribution of particulate emissions of heavy-duty engines in real world test cycles

NASA Astrophysics Data System (ADS)

Lehmann, Urs; Mohr, Martin; Schweizer, Thomas; Rütter, Josef

Five in-service engines in heavy-duty trucks complying with Euro II emission standards were measured on a dynamic engine test bench at EMPA. The particulate matter (PM) emissions of these engines were investigated by number and mass measurements. The mass of the total PM was evaluated using the standard gravimetric measurement method, the total number concentration and the number size distribution were measured by a Condensation Particle Counter (lower particle size cut-off: 7 nm) and an Electrical Low Pressure Impactor (lower particle size: 32 nm), respectively. The transient test cycles used represent either driving behaviour on the road (real-world test cycles) or a type approval procedure. They are characterised by the cycle power, the average cycle power and by a parameter for the cycle dynamics. In addition, the particle number size distribution was determined at two steady-state operating modes of the engine using a Scanning Mobility Particle Sizer. For quality control, each measurement was repeated at least three times under controlled conditions. It was found that the number size distributions as well as the total number concentration of emitted particles could be measured with a good repeatability. Total number concentration was between 9×10 11 and 1×10 13 particles/s (3×10 13-7×10 14 p/kWh) and mass concentration was between 0.09 and 0.48 g/kWh. For all transient cycles, the number mean diameter of the distributions lay typically at about 120 nm for aerodynamic particle diameter and did not vary significantly. In general, the various particle measurement devices used reveal the same trends in particle emissions. We looked at the correlation between specific gravimetric mass emission (PM) and total particle number concentration. The correlation tends to be influenced more by the different engines than by the test cycles.

Comprehensive Characterization Of Ultrafine Particulate Emission From 2007 Diesel Engines: PM Size Distribution, Loading And Indidividual Particle Size And Composition.

NASA Astrophysics Data System (ADS)

Zelenyuk, A.; Cuadra-Rodriguez, L. A.; Imre, D.; Shimpi, S.; Warey, A.

2006-12-01

The strong absorption of solar radiation by black carbon (BC) impacts the atmospheric radiative balance in a complex and significant manner. One of the most important sources of BC is vehicular emissions, of which diesel represents a significant fraction. To address this issue the EPA has issues new stringent regulations that will be in effect in 2007, limiting the amount of particulate mass that can be emitted by diesel engines. The new engines are equipped with aftertreatments that reduce PM emissions to the point, where filter measurements are subject to significant artifacts and characterization by other techniques presents new challenges. We will present the results of the multidisciplinary study conducted at the Cummins Technical Center in which a suite of instruments was deployed to yield comprehensive, temporally resolved information on the diesel exhaust particle loadings and properties in real-time: Particle size distributions were measured by Engine Exhaust Particle Sizer (EEPS) and Scanning Mobility Particle Sizer (SMPS). Total particle diameter concentration was obtained using Electrical Aerosol Detector (EAD). Laser Induced Incandescence and photoacoustic techniques were used to monitor the PM soot content. Single Particle Laser Ablation Time-of- flight Mass Spectrometer (SPLAT) provided the aerodynamic diameter and chemical composition of individual diesel exhaust particles. Measurements were conducted on a number of heavy duty diesel engines operated under variety of operating conditions, including FTP transient cycles, ramped-modal cycles and steady states runs. We have also characterized PM emissions during diesel particulate filter regeneration cycles. We will present a comparison of PM characteristics observed during identical cycles, but with and without the use of aftertreatment. A total of approximately 100,000 individual particles were sized and their composition characterized by SPLAT. The aerodynamic size distributions of the characterized particles were between 50 and 300 nm, depending on engine operating conditions and particle composition. We will show that while the drastically reduced diesel PM emissions often render the PM filter measurements inadequate due to organic vapor artifacts SPLAT demonstrated its capability to provide real-time information on size and composition of individual diesel exhaust particles as function of engine operating conditions with better than 1 minute resolution.

Predictive modeling and reducing cyclic variability in autoignition engines

DOEpatents

Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

2016-08-30

Methods and systems are provided for controlling a vehicle engine to reduce cycle-to-cycle combustion variation. A predictive model is applied to predict cycle-to-cycle combustion behavior of an engine based on observed engine performance variables. Conditions are identified, based on the predicted cycle-to-cycle combustion behavior, that indicate high cycle-to-cycle combustion variation. Corrective measures are then applied to prevent the predicted high cycle-to-cycle combustion variation.

Integrating Science and Engineering to Implement Evidence-Based Practices in Health Care Settings.

PubMed

Wu, Shinyi; Duan, Naihua; Wisdom, Jennifer P; Kravitz, Richard L; Owen, Richard R; Sullivan, J Greer; Wu, Albert W; Di Capua, Paul; Hoagwood, Kimberly Eaton

2015-09-01

Integrating two distinct and complementary paradigms, science and engineering, may produce more effective outcomes for the implementation of evidence-based practices in health care settings. Science formalizes and tests innovations, whereas engineering customizes and optimizes how the innovation is applied tailoring to accommodate local conditions. Together they may accelerate the creation of an evidence-based healthcare system that works effectively in specific health care settings. We give examples of applying engineering methods for better quality, more efficient, and safer implementation of clinical practices, medical devices, and health services systems. A specific example was applying systems engineering design that orchestrated people, process, data, decision-making, and communication through a technology application to implement evidence-based depression care among low-income patients with diabetes. We recommend that leading journals recognize the fundamental role of engineering in implementation research, to improve understanding of design elements that create a better fit between program elements and local context.

Tissue engineering and regenerative medicine in applied research: a year in review of 2014.

PubMed

Lin, Xunxun; Huang, Jia; Shi, Yuan; Liu, Wei

2015-04-01

Tissue engineering and regenerative medicine (TERM) remains to be one of the fastest growing fields, which covers a wide scope of topics of both basic and applied biological researches. This overview article summarized the advancements in applied researches of TERM area, including stem cell-mediated tissue regeneration, material science, and TERM clinical trial. These achievements demonstrated the great potential of clinical regenerative therapy of tissue/organ disease or defect through stem cells and tissue engineering approaches.

National Dam Safety Program. Main Tailings Dam (MO 31082), Mississippi - St. Francis Basin, Madison County, Missouri. Phase I Inspection Report.

DTIC Science & Technology

1979-06-01

failure and other information. These reports were prepared by personnel from the Mis- souri Geology and Land Survey, Applied Engineering and Urban...34Report of the National Lead Stifling Basin Washout, Madison County, Missouri", Applied Engineering and Urban Geology, Geo- logy and Land Survey, 30...failure and other information are contained in reports by personnel from the Missouri Geology and Land Survey, Applied Engineering and Urban Geology

National Dam Safety Program. Bray Lake Dam (MO 30098), Osage - Gasconade Basin, Phelps County, Missouri. Phase I Inspection Report.

DTIC Science & Technology

1979-12-01

Geologist Applied Engineering & Urban Geology Missouri Geological Survey May 6, 1974 Sheet 6, Appendix B For file Only DEAN LAKE SITE (Formerly Bray...time to point out these problems that you have been discussing. ,J. Hadley Williams Geologist and Chief Applied Engineering & Urban Geology Missouri...Geologist Applied Engineering & Urban Geology Missouri Geological Survey June 27, 1974 Sheet 9, Appendix B FOR FILE ONLY L • BRAYS LAKE RECONNAISSANCE PHELPS

Research in progress in applied mathematics, numerical analysis, and computer science

NASA Technical Reports Server (NTRS)

1990-01-01

Research conducted at the Institute in Science and Engineering in applied mathematics, numerical analysis, and computer science is summarized. The Institute conducts unclassified basic research in applied mathematics in order to extend and improve problem solving capabilities in science and engineering, particularly in aeronautics and space.

Properties of jet engine combustion particles during the PartEmis experiment: Microphysics and Chemistry

NASA Astrophysics Data System (ADS)

Petzold, A.; Stein, C.; Nyeki, S.; Gysel, M.; Weingartner, E.; Baltensperger, U.; Giebl, H.; Hitzenberger, R.; Döpelheuer, A.; Vrchoticky, S.; Puxbaum, H.; Johnson, M.; Hurley, C. D.; Marsh, R.; Wilson, C. W.

2003-07-01

The particles emitted from an aircraft engine combustor were investigated in the European project PartEmis. Measured aerosol properties were mass and number concentration, size distribution, mixing state, thermal stability of internally mixed particles, hygroscopicity, and cloud condensation nuclei (CCN) activation potential. The combustor operation conditions corresponded to modern and older engine gas path temperatures at cruise altitude, with fuel sulphur contents (FSC) of 50, 410, and 1270 μg g-1. Operation conditions and FSC showed only a weak influence on the microphysical aerosol properties, except for hygroscopic and CCN properties. Particles of size D >= 30 nm were almost entirely internally mixed. Particles of sizes D < 20 nm showed a considerable volume fraction of compounds that volatilise at 390 K (10-15%) and 573 K (4-10%), while respective fractions decreased to <5% for particles of size D >= 50 nm.

Evolution of deep-bed filtration of engine exhaust particulates with trapped mass

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

Viswanathan, Sandeep; Rothamer, David A.; Foster, David E.

Micro-scale filtration experiments were performed on cordierite filter samples using particulate matter (PM) generated by a spark-ignition direct-injection (SIDI) engine fueled with tier II EEE certification gasoline. Size-resolved mass and number concentrations were obtained from several engine operating conditions. The resultant mass-mobility relationships showed weak dependence on the operating condition. An integrated particle size distribution (IPSD) method was used estimate the PM mass concentration in the exhaust stream from the SIDI engine and a heavy duty diesel (HDD) engine. The average estimated mass concentration between all conditions was ~77****** % of the gravimetric measurements performed on Teflon filters. Despite themore » relatively low elemental carbon fraction (~0.4 to 0.7), the IPSD mass for stoichiometric SIDI exhaust was ~83±38 % of the gravimetric measurement. Identical cordierite filter samples with properties representative of diesel particulate filters were sequentially loaded with PM from the different SIDI engine operating conditions, in order of increasing PM mass concentration. Simultaneous particle size distribution measurements upstream and downstream of the filter sample were used to evaluate filter performance evolution and the instantaneous trapped mass within the filter for two different filter face velocities. The evolution of filtration performance for the different samples was sensitive only to trapped mass, despite using PM from a wide range of operating conditions. Higher filtration velocity resulted in a more rapid shift in the most penetrating particle size towards smaller mobility diameters.« less

A Nanometer Aerosol Size Analyzer (nASA) for Rapid Measurement of High-concentration Size Distributions

NASA Astrophysics Data System (ADS)

Han, Hee-Siew; Chen, Da-Ren; Pui, David Y. H.; Anderson, Bruce E.

2000-03-01

We have developed a fast-response nanometer aerosol size analyzer (nASA) that is capable of scanning 30 size channels between 3 and 100 nm in a total time of 3 s. The analyzer includes a bipolar charger (Po210), an extended-length nanometer differential mobility analyzer (Nano-DMA), and an electrometer (TSI 3068). This combination of components provides particle size spectra at a scan rate of 0.1 s per channel free of uncertainties caused by response-time-induced smearing. The nASA thus offers a fast response for aerosol size distribution measurements in high-concentration conditions and also eliminates the need for applying a de-smearing algorithm to resulting data. In addition, because of its thermodynamically stable means of particle detection, the nASA is useful for applications requiring measurements over a broad range of sample pressures and temperatures. Indeed, experimental transfer functions determined for the extended-length Nano-DMA using the tandem differential mobility analyzer (TDMA) technique indicate the nASA provides good size resolution at pressures as low as 200 Torr. Also, as was demonstrated in tests to characterize the soot emissions from the J85-GE engine of a T-38 aircraft, the broad dynamic concentration range of the nASA makes it particularly suitable for studies of combustion or particle formation processes. Further details of the nASA performance as well as results from calibrations, laboratory tests and field applications are presented below.

A Nanometer Aerosol Size Analyzer (nASA) for Rapid Measurement of High-Concentration Size Distributions

NASA Technical Reports Server (NTRS)

Han, Hee-Siew; Chen, Da-Ren; Pui, David Y. H.; Anderson, Bruce E.

2001-01-01

We have developed a fast-response Nanometer Aerosol Size Analyzer (nASA) that is capable of scanning 30 size channels between 3 and 100 nm in a total time of 3 seconds. The analyzer includes a bipolar charger (P0210), an extended-length Nanometer Differential Mobility Analyzer (Nano-DMA), and an electrometer (TSI 3068). This combination of components provides particle size spectra at a scan rate of 0.1 second per channel free of uncertainties caused by response-time-induced smearing. The nASA thus offers a fast response for aerosol size distribution measurements in high-concentration conditions and also eliminates the need for applying a de-smearing algorithm to resulting data. In addition, because of its thermodynamically stable means of particle detection, the nASA is useful for applications requiring measurements over a broad range of sample pressures and temperatures. Indeed, experimental transfer functions determined for the extended-length Nano-DMA using the Tandem Differential Mobility Analyzer (TDMA) technique indicate the nASA provides good size resolution at pressures as low as 200 Torr. Also, as was demonstrated in tests to characterize the soot emissions from the J85-GE engine of a T38 aircraft, the broad dynamic concentration range of the nASA makes it particularly suitable for studies of combustion or particle formation processes. Further details of the nASA performance as well as results from calibrations, laboratory tests and field applications are presented.

Novel strategy for protein exploration: high-throughput screening assisted with fuzzy neural network.

PubMed

Kato, Ryuji; Nakano, Hideo; Konishi, Hiroyuki; Kato, Katsuya; Koga, Yuchi; Yamane, Tsuneo; Kobayashi, Takeshi; Honda, Hiroyuki

2005-08-19

To engineer proteins with desirable characteristics from a naturally occurring protein, high-throughput screening (HTS) combined with directed evolutional approach is the essential technology. However, most HTS techniques are simple positive screenings. The information obtained from the positive candidates is used only as results but rarely as clues for understanding the structural rules, which may explain the protein activity. In here, we have attempted to establish a novel strategy for exploring functional proteins associated with computational analysis. As a model case, we explored lipases with inverted enantioselectivity for a substrate p-nitrophenyl 3-phenylbutyrate from the wild-type lipase of Burkhorderia cepacia KWI-56, which is originally selective for (S)-configuration of the substrate. Data from our previous work on (R)-enantioselective lipase screening were applied to fuzzy neural network (FNN), bioinformatic algorithm, to extract guidelines for screening and engineering processes to be followed. FNN has an advantageous feature of extracting hidden rules that lie between sequences of variants and their enzyme activity to gain high prediction accuracy. Without any prior knowledge, FNN predicted a rule indicating that "size at position L167," among four positions (L17, F119, L167, and L266) in the substrate binding core region, is the most influential factor for obtaining lipase with inverted (R)-enantioselectivity. Based on the guidelines obtained, newly engineered novel variants, which were not found in the actual screening, were experimentally proven to gain high (R)-enantioselectivity by engineering the size at position L167. We also designed and assayed two novel variants, namely FIGV (L17F, F119I, L167G, and L266V) and FFGI (L17F, L167G, and L266I), which were compatible with the guideline obtained from FNN analysis, and confirmed that these designed lipases could acquire high inverted enantioselectivity. The results have shown that with the aid of bioinformatic analysis, high-throughput screening can expand its potential for exploring vast combinatorial sequence spaces of proteins.

Application of Extrusion-Based Hydrogel Bioprinting for Cartilage Tissue Engineering.

PubMed

You, Fu; Eames, B Frank; Chen, Xiongbiao

2017-07-23

Extrusion-based bioprinting (EBB) is a rapidly developing technique that has made substantial progress in the fabrication of constructs for cartilage tissue engineering (CTE) over the past decade. With this technique, cell-laden hydrogels or bio-inks have been extruded onto printing stages, layer-by-layer, to form three-dimensional (3D) constructs with varying sizes, shapes, and resolutions. This paper reviews the cell sources and hydrogels that can be used for bio-ink formulations in CTE application. Additionally, this paper discusses the important properties of bio-inks to be applied in the EBB technique, including biocompatibility, printability, as well as mechanical properties. The printability of a bio-ink is associated with the formation of first layer, ink rheological properties, and crosslinking mechanisms. Further, this paper discusses two bioprinting approaches to build up cartilage constructs, i.e., self-supporting hydrogel bioprinting and hybrid bioprinting, along with their applications in fabricating chondral, osteochondral, and zonally organized cartilage regenerative constructs. Lastly, current limitations and future opportunities of EBB in printing cartilage regenerative constructs are reviewed.

Effectiveness of off-line and web-based promotion of health information web sites.

PubMed

Jones, Craig E; Pinnock, Carole B

2002-01-01

The relative effectiveness of off-line and web-based promotional activities in increasing the use of health information web sites by target audiences were compared. Visitor sessions were classified according to their method of arrival at the site (referral) as external web site, search engine, or "no referrer" (i.e., visitor arriving at the site by inputting URL or using bookmarks). The number of Australian visitor sessions correlated with no referrer referrals but not web site or search-engine referrals. Results showed that the targeted consumer group is more likely to access the web site as a result of off-line promotional activities. The properties of target audiences likely to influence the effectiveness of off-line versus on-line promotional strategies include the size of the Internet using population of the target audience, their proficiency in the use of the Internet, and the increase in effectiveness of off-line promotional activities when applied to locally defined target audiences.

Inlet Aerodynamics and Ram Drag of Laser-Propelled Lightcraft Vehicles

NASA Astrophysics Data System (ADS)

Langener, Tobias; Myrabo, Leik; Rusak, Zvi

2010-05-01

Numerical simulations are used to study the aerodynamic inlet properties of three axisymmetric configurations of laser-propelled Lightcraft vehicles operating at subsonic, transonic and supersonic speeds up to Mach 5. The 60 cm vehicles were sized for launching 0.1-1.0 kg nanosatellites with combined-cycle airbreathing/rocket engines, transitioning between propulsion modes at roughly Mach 5-6. Results provide the pressure, temperature, density, and velocity flowfields around and through the three representative vehicle/engine configurations, as well as giving the resulting ram drag and total drag coefficients—all as a function of flight Mach number. Simulations with rotating boundaries were also carried out, since for stability reasons, Lightcraft are normally spun up before lift-off. Given the three alternatives, it is demonstrated that the optimal geometry for minimum drag is the configuration with a parabola nose; hence, these inlet flow conditions are being applied in subsequent "direct connect" 2D laser propulsion experiments in a small transonic flow facility.

Chitosan-chitin nanocrystal composite scaffolds for tissue engineering.

PubMed

Liu, Mingxian; Zheng, Huanjun; Chen, Juan; Li, Shuangli; Huang, Jianfang; Zhou, Changren

2016-11-05

Chitin nanocrystals (CNCs) with length and width of 300 and 20nm were uniformly dispersed in chitosan (CS) solution. The CS/CNCs composite scaffolds prepared utilizing a dispersion-based freeze dry approach exhibit significant enhancement in compressive strength and modulus compared with pure CS scaffold both in dry and wet state. A well-interconnected porous structure with size in the range of 100-200μm and over 80% porosity are found in the composite scaffolds. The crystal structure of CNCs is retained in the composite scaffolds. The incorporation of CNCs leads to increase in the scaffold density and decrease in the water swelling ratio. Moreover, the composite scaffolds are successfully applied as scaffolds for MC3T3-E1 osteoblast cells, showing their excellent biocompatibility and low cytotoxicity. The results of fluorescent micrographs images reveal that CNCs can markedly promote the cell adhesion and proliferation of the osteoblast on CS. The biocompatible composite scaffolds with enhanced mechanical properties have potential application in bone tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

Compressive Properties of Metal Matrix Syntactic Foams in Free and Constrained Compression

NASA Astrophysics Data System (ADS)

Orbulov, Imre Norbert; Májlinger, Kornél

2014-06-01

Metal matrix syntactic foam (MMSF) blocks were produced by an inert gas-assisted pressure infiltration technique. MMSFs are advanced hollow sphere reinforced-composite materials having promising application in the fields of aviation, transport, and automotive engineering, as well as in civil engineering. The produced blocks were investigated in free and constrained compression modes, and besides the characteristic mechanical properties, their deformation mechanisms and failure modes were studied. In the tests, the chemical composition of the matrix material, the size of the reinforcing ceramic hollow spheres, the applied heat treatment, and the compression mode were considered as investigation parameters. The monitored mechanical properties were the compressive strength, the fracture strain, the structural stiffness, the fracture energy, and the overall absorbed energy. These characteristics were strongly influenced by the test parameters. By the proper selection of the matrix and the reinforcement and by proper design, the mechanical properties of the MMSFs can be effectively tailored for specific and given applications.

Approach to Modeling Boundary Layer Ingestion Using a Fully Coupled Propulsion-RANS Model

NASA Technical Reports Server (NTRS)

Gray, Justin; Mader, Charles A.; Kenway, Gaetan K. W.; Martins, Joaquim R. R. A.

2017-01-01

Although boundary layer ingestion (BLI), or wake ingestion, is commonly applied in marine propulsion applications, it has not yet seen wide-spread adoption in aircraft applications. However, recent studies have predicted that BLI offers a potential for a 10 reduction in aircraft fuel burn, even on a fairly traditional aircraft configuration. This dramatic reduction in fuel burn is achieved via tight integration of the propulsion system and airframe aerodynamics, but actually realizing such large performance gains will require modifying the aircraft design process to account for this integration. Traditionally, in aircraft design, the airframe and the propulsion system are designed separately and then the engine sizing is managed with a rubber-engine approach. This works when the propulsion system is placed in the free-stream air, away from the aerodynamic influence of the airframe, and it is reasonable to assume that small changes to either system won't have a strong impact on the other.

78 FR 5710 - Airworthiness Directives; Engine Alliance Turbofan Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-28

... Airworthiness Directives; Engine Alliance Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT... all Engine Alliance GP7270 and GP7277 turbofan engines. This AD requires initial and repetitive...) Applicability This AD applies to all Engine Alliance GP7270 and GP7277 turbofan engines with a high-pressure...

Cellular Stress Response to Engineered Nanoparticles: Effect of Size, Surface Coating, and Cellular Uptake

EPA Science Inventory

CELLULAR STRESS RESPONSE TO ENGINEERED NANOPARTICLES: EFFECT OF SIZE, SURFACE COATING, AND CELLULAR UPTAKE RY Prasad 1, JK McGee2, MG Killius1 D Ackerman2, CF Blackman2 DM DeMarini2 , SO Simmons2 1 Student Services Contractor, US EPA, RTP, NC 2 US EPA, RTP, NC The num...

Virtual Collaborative Environments for System of Systems Engineering and Applications for ISAT

NASA Technical Reports Server (NTRS)

Dryer, David A.

2002-01-01

This paper describes an system of systems or metasystems approach and models developed to help prepare engineering organizations for distributed engineering environments. These changes in engineering enterprises include competition in increasingly global environments; new partnering opportunities caused by advances in information and communication technologies, and virtual collaboration issues associated with dispersed teams. To help address challenges and needs in this environment, a framework is proposed that can be customized and adapted for NASA to assist in improved engineering activities conducted in distributed, enhanced engineering environments. The approach is designed to prepare engineers for such distributed collaborative environments by learning and applying e-engineering methods and tools to a real-world engineering development scenario. The approach consists of two phases: an e-engineering basics phase and e-engineering application phase. The e-engineering basics phase addresses skills required for e-engineering. The e-engineering application phase applies these skills in a distributed collaborative environment to system development projects.

Applying systems engineering to implement an evidence-based intervention at a community health center.

PubMed

Tu, Shin-Ping; Feng, Sherry; Storch, Richard; Yip, Mei-Po; Sohng, HeeYon; Fu, Mingang; Chun, Alan

2012-11-01

Impressive results in patient care and cost reduction have increased the demand for systems-engineering methodologies in large health care systems. This Report from the Field describes the feasibility of applying systems-engineering techniques at a community health center currently lacking the dedicated expertise and resources to perform these activities.

FísicActiva: Applying Active Learning Strategies to a Large Engineering Lecture

ERIC Educational Resources Information Center

Auyuanet, Adriana; Modzelewski, Helena; Loureiro, Silvia; Alessandrini, Daniel; Míguez, Marina

2018-01-01

This paper presents and analyses the results obtained by applying Active Learning techniques in overcrowded Physics lectures at the University of the Republic, Uruguay. The course referred to is Physics 1, the first Physics course that all students of the Faculty of Engineering take in their first semester for all the Engineering-related careers.…

Applying Systems Engineering to Implement an Evidence-based Intervention at a Community Health Center

PubMed Central

Tu, Shin-Ping; Feng, Sherry; Storch, Richard; Yip, Mei-Po; Sohng, HeeYon; Fu, Mingang; Chun, Alan

2013-01-01

Summary Impressive results in patient care and cost reduction have increased the demand for systems-engineering methodologies in large health care systems. This Report from the Field describes the feasibility of applying systems-engineering techniques at a community health center currently lacking the dedicated expertise and resources to perform these activities. PMID:23698657

40 CFR 86.1930 - What special provisions apply from 2005 through 2010?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Manufacturer-Run In-Use Testing Program for Heavy-Duty Diesel Engines § 86.1930 What special provisions apply from 2005 through 2010? (a) We may direct you to test engines under this subpart for emissions other...

The Errors Sources Affect to the Results of One-Way Nested Ocean Regional Circulation Model

NASA Astrophysics Data System (ADS)

Pham, S. V.

2016-02-01

Pham-Van Sy1, Jin Hwan Hwang2 and Hyeyun Ku3 Dept. of Civil & Environmental Engineering, Seoul National University, KoreaEmail: 1phamsymt@gmail.com (Corresponding author) Email: 2jinhwang@snu.ac.krEmail: 3hyeyun.ku@gmail.comAbstractThe Oceanic Regional Circulation Model (ORCM) is an essential tool in resolving highly a regional scale through downscaling dynamically the results from the roughly revolved global model. However, when dynamic downscaling from a coarse resolution of the global model or observations to the small scale, errors are generated due to the different sizes of resolution and lateral updating frequency. This research evaluated the effect of four main sources on the results of the ocean regional circulation model (ORCMs) during downscaling and nesting the output data from the ocean global circulation model (OGCMs). Representative four error sources should be the way of the LBC formulation, the spatial resolution difference between driving and driven data, the frequency for up-dating LBCs and domain size. Errors which are contributed from each error source to the results of the ORCMs are investigated separately by applying the Big-Brother Experiment (BBE). Within resolution of 3km grid point of the ORCMs imposing in the BBE framework, it clearly exposes that the simulation results of the ORCMs significantly depend on the domain size and specially the spatial and temporal resolution of lateral boundary conditions (LBCs). The ratio resolution of spatial resolution between driving data and driven model could be up to 3, the updating frequency of the LBCs can be up to every 6 hours per day. The optimal domain size of the ORCMs could be smaller than the OGCMs' domain size around 2 to 10 times. Key words: ORCMs, error source, lateral boundary conditions, domain size Acknowledgement: This research was supported by grants from the Korean Ministry of Oceans and Fisheries entitled as "Developing total management system for the Keum river estuary and coast" and "Development of Technology for CO2 Marine Geological Storage". We also thank to the administrative supports of the Integrated Research Institute of Construction and Environmental Engineering of the Seoul National University.

40 CFR 1042.345 - Reporting.

Code of Federal Regulations, 2010 CFR

2010-07-01

... test engine, including the engine family's identification and the engine's model year, build date... you developed and applied the Green Engine Factor, if applicable. (5) Identify how you accumulated...

Cognitive engineering and health informatics: Applications and intersections.

PubMed

Hettinger, A Zachary; Roth, Emilie M; Bisantz, Ann M

2017-03-01

Cognitive engineering is an applied field with roots in both cognitive science and engineering that has been used to support design of information displays, decision support, human-automation interaction, and training in numerous high risk domains ranging from nuclear power plant control to transportation and defense systems. Cognitive engineering provides a set of structured, analytic methods for data collection and analysis that intersect with and complement methods of Cognitive Informatics. These methods support discovery of aspects of the work that make performance challenging, as well as the knowledge, skills, and strategies that experts use to meet those challenges. Importantly, cognitive engineering methods provide novel representations that highlight the inherent complexities of the work domain and traceable links between the results of cognitive analyses and actionable design requirements. This article provides an overview of relevant cognitive engineering methods, and illustrates how they have been applied to the design of health information technology (HIT) systems. Additionally, although cognitive engineering methods have been applied in the design of user-centered informatics systems, methods drawn from informatics are not typically incorporated into a cognitive engineering analysis. This article presents a discussion regarding ways in which data-rich methods can inform cognitive engineering. Copyright © 2017 Elsevier Inc. All rights reserved.

Career Services | College of Engineering & Applied Science

Science.gov Websites

Engineering & Applied Science uses the university's PantherJobs to help students post resumes, search and ' resumes, post available positions and schedule interviews. Co-ops and Internships Co-ops and Internships

40 CFR 1045.1 - Does this part apply for my products?

Code of Federal Regulations, 2011 CFR

2011-07-01

... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Overview... exhaust emissions apply to new, spark-ignition propulsion marine engines beginning with the 2010 model...

40 CFR 1045.1 - Does this part apply for my products?

Code of Federal Regulations, 2012 CFR

2012-07-01

... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Overview... exhaust emissions apply to new, spark-ignition propulsion marine engines beginning with the 2010 model...

40 CFR 1045.1 - Does this part apply for my products?

Code of Federal Regulations, 2013 CFR

2013-07-01

... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Overview... exhaust emissions apply to new, spark-ignition propulsion marine engines beginning with the 2010 model...

40 CFR 1045.1 - Does this part apply for my products?

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Overview... exhaust emissions apply to new, spark-ignition propulsion marine engines beginning with the 2010 model...

40 CFR 1045.1 - Does this part apply for my products?

Code of Federal Regulations, 2010 CFR

2010-07-01

... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS Overview... exhaust emissions apply to new, spark-ignition propulsion marine engines beginning with the 2010 model...

40 CFR 1039.102 - What exhaust emission standards and phase-in allowances apply for my engines in model year 2014...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Requirements § 1039.102 What exhaust emission standards and phase-in allowances apply for my engines in model year 2014 and earlier? The exhaust emission standards of this section apply for 2014 and earlier model years. See § 1039.101 for exhaust emission standards that apply to later model years. See 40 CFR 89.112...

40 CFR 1039.102 - What exhaust emission standards and phase-in allowances apply for my engines in model year 2014...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Requirements § 1039.102 What exhaust emission standards and phase-in allowances apply for my engines in model year 2014 and earlier? The exhaust emission standards of this section apply for 2014 and earlier model years. See § 1039.101 for exhaust emission standards that apply to later model years. See 40 CFR 89.112...

40 CFR 1039.102 - What exhaust emission standards and phase-in allowances apply for my engines in model year 2014...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Requirements § 1039.102 What exhaust emission standards and phase-in allowances apply for my engines in model year 2014 and earlier? The exhaust emission standards of this section apply for 2014 and earlier model years. See § 1039.101 for exhaust emission standards that apply to later model years. See 40 CFR 89.112...

40 CFR 1039.102 - What exhaust emission standards and phase-in allowances apply for my engines in model year 2014...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Requirements § 1039.102 What exhaust emission standards and phase-in allowances apply for my engines in model year 2014 and earlier? The exhaust emission standards of this section apply for 2014 and earlier model years. See § 1039.101 for exhaust emission standards that apply to later model years. See 40 CFR 89.112...

Super-focusing of center-covered engineered microsphere.

PubMed

Wu, Mengxue; Chen, Rui; Soh, Jiahao; Shen, Yue; Jiao, Lishi; Wu, Jianfeng; Chen, Xudong; Ji, Rong; Hong, Minghui

2016-08-16

Engineered microsphere possesses the advantage of strong light manipulation at sub-wavelength scale and emerges as a promising candidate to shrink the focal spot size. Here we demonstrated a center-covered engineered microsphere which can adjust the transverse component of the incident beam and achieve a sharp photonic nanojet. Modification of the beam width and working distance of the photonic nanojet were achieved by tuning the cover ratio of the engineered microsphere, leading to a sharp spot size which exceeded the optical diffraction limit. At a wavelength of 633 nm, a focal spot of 245 nm (0.387 λ) was achieved experimentally under plane wave illumination. Strong localized field with Bessel-like distribution was demonstrated by employing the linearly polarized beam and a center-covered mask being engineered on the microsphere.

Super-focusing of center-covered engineered microsphere

PubMed Central

Wu, Mengxue; Chen, Rui; Soh, Jiahao; Shen, Yue; Jiao, Lishi; Wu, Jianfeng; Chen, Xudong; Ji, Rong; Hong, Minghui

2016-01-01

Engineered microsphere possesses the advantage of strong light manipulation at sub-wavelength scale and emerges as a promising candidate to shrink the focal spot size. Here we demonstrated a center-covered engineered microsphere which can adjust the transverse component of the incident beam and achieve a sharp photonic nanojet. Modification of the beam width and working distance of the photonic nanojet were achieved by tuning the cover ratio of the engineered microsphere, leading to a sharp spot size which exceeded the optical diffraction limit. At a wavelength of 633 nm, a focal spot of 245 nm (0.387 λ) was achieved experimentally under plane wave illumination. Strong localized field with Bessel-like distribution was demonstrated by employing the linearly polarized beam and a center-covered mask being engineered on the microsphere. PMID:27528093

Ultra-efficient Engine Diameter Study

NASA Technical Reports Server (NTRS)

Daggett, David L.; Brown, Stephen T.; Kawai, Ron T.

2003-01-01

Engine fan diameter and Bypass Ratio (BPR) optimization studies have been conducted since the beginning of the turbofan age with the recognition that reducing the engine core jet velocity and increasing fan mass flow rate generally increases propulsive efficiency. However, performance tradeoffs limit the amount of fan flow achievable without reducing airplane efficiency. This study identifies the optimum engine fan diameter and BPR, given the advanced Ultra-Efficient Engine Technology (UEET) powerplant efficiencies, for use on an advanced subsonic airframe. Engine diameter studies have historically focused on specific engine size options, and were limited by existing technology and transportation infrastructure (e.g., ability to fit bare engines through aircraft doors and into cargo holds). This study is unique in defining the optimum fan diameter and drivers for future 2015 (UEET) powerplants while not limiting engine fan diameter by external constraints. This report follows on to a study identifying the system integration issues of UEET engines. This Engine Diameter study was managed by Boeing Phantom Works, Seattle, Washington through the NASA Glenn Revolutionary Aero Space Engine Research (RASER) contract under task order 10. Boeing Phantom Works, Huntington Beach, completed the engine/airplane sizing optimization, while the Boeing Commercial Airplane group (BCA) provided design oversight. A separate subcontract to support the overall project was issued to Tuskegee University.

The Effect of STEM Learning through the Project of Designing Boat Model toward Student STEM Literacy

NASA Astrophysics Data System (ADS)

Tati, T.; Firman, H.; Riandi, R.

2017-09-01

STEM Learning focusses on development of STEM-literate society, the research about implementation of STEM learning to develope students’ STEM literacy is still limited. This study is aimed to examine the effect of implementation STEM learning through the project of designing boat model on students STEM literacy in energy topic. The method of this study was a quasi-experiment with non-randomized pretest-posttest control group design. There were two classes involved, the experiment class used Project Based Learning with STEM approach and control class used Project-Based Learning without STEM approach. A STEM Literacy test instrument was developed to measure students STEM literacy which consists of science literacy, mathematics literacy, and technology-engineering literacy. The analysis showed that there were significant differences on improvement science literacy, mathematics technology-engineering between experiment class and control class with effect size more than 0.8 (large effect). The difference of improvement of STEM literacy between experiment class and control class is caused by the existence of design engineering activity which required students to apply the knowledge from every field of STEM. The challenge that was faced in STEM learning through design engineering activity was how to give the students practice to integrate STEM field in solving the problems. In additional, most of the students gave positive response toward implementation of STEM learning through design boat model project.

Control of cell growth on 3D-printed cell culture platforms for tissue engineering.

PubMed

Tan, Zhikai; Liu, Tong; Zhong, Juchang; Yang, Yikun; Tan, Weihong

2017-12-01

Biocompatible tissue growth has excellent prospects for tissue engineering. These tissues are built over scaffolds, which can influence aspects such as cell adhesion, proliferation rate, morphology, and differentiation. However, the ideal 3D biological structure has not been developed yet. Here, we applied the electro-hydrodynamic jet (E-jet) 3D printing technology using poly-(lactic-co-glycolic acid, PLGA) solution to print varied culture platforms for engineered tissue structures. The effects of different parameters (electrical voltage, plotting speed, and needle sizes) on the outcome were investigated. We compared the biological compatibility of the 3D printed culture platforms with that of random fibers. Finally, we used the 3D-printed PLGA platforms to culture fibroblasts, the main cellular components of loose connective tissue. The results show that the E-jet printed platforms could guide and improve cell growth. These highly aligned fibers were able to support cellular alignment and proliferation. Cell angle was consistent with the direction of the fibers, and cells cultured on these fibers showed a much faster migration, potentially enhancing wound healing performance. Thus, the potential of this technology for 3D biological printing is large. This process can be used to grow biological scaffolds for the engineering of tissues. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3281-3292, 2017. © 2017 Wiley Periodicals, Inc.

The effects of biodiesels on semivolatile and nonvolatile particulate matter emissions from a light-duty diesel engine.

PubMed

Cheng, Yuan; Li, Shao-Meng; Liggio, John; Hayden, Katherine; Han, Yuemei; Stroud, Craig; Chan, Tak; Poitras, Marie-Josée

2017-11-01

Semivolatile organic compounds (SVOCs) represent a dominant category of secondary organic aerosol precursors that are increasingly included in air quality models. In the present study, an experimental system was developed and applied to a light-duty diesel engine to determine the emission factors of particulate SVOCs (pSVOCs) and nonvolatile particulate matter (PM) components at dilution ratios representative of ambient conditions. The engine was tested under three steady-state operation modes, using ultra-low-sulfur diesel (ULSD), three types of pure biodiesels and their blends with ULSD. For ULSD, the contribution of pSVOCs to total particulate organic matter (POM) mass in the engine exhaust ranged between 21 and 85%. Evaporation of pSVOCs from the diesel particles during dilution led to decreases in the hydrogen to carbon ratio of POM and the PM number emission factor of the particles. Substituting biodiesels for ULSD could increase pSVOCs emissions but brought on large reductions in black carbon (BC) emissions. Among the biodiesels tested, tallow/used cooking oil (UCO) biodiesel showed advantages over soybean and canola biodiesels in terms of both pSVOCs and nonvolatile PM emissions. It is noteworthy that PM properties, such as particle size and BC mass fraction, differed substantially between emissions from conventional diesel and biodiesels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental investigation on the performance, gaseous and particulate emissions of a methanol fumigated diesel engine.

PubMed

Cheng, C H; Cheung, C S; Chan, T L; Lee, S C; Yao, C D

2008-01-15

Experiments were conducted on a 4-cylinder direct-injection diesel engine with fumigation methanol injected into the air intake of each cylinder. The fumigation methanol was injected to top up 10%, 20% and 30% of the power output under different engine operating conditions. The effects of fumigation methanol on engine performance, gaseous emissions and particulate emission were investigated. The experimental results show that there is a decrease in the brake thermal efficiency when fumigation methanol is applied, except at the highest load of 0.67 MPa. At low loads, the brake thermal efficiency decreases with increase in fumigation methanol; but at high loads, it increases with increase in fumigation methanol. The fumigation method results in a significant increase in hydrocarbon (HC), carbon monoxide (CO), and nitrogen dioxide (NO(2)) emissions. The concentration of nitrogen oxides (NOx) is significantly reduced except at close to full load condition. There is also a reduction in the smoke opacity and the particulate matter (PM) mass concentration. For the submicron particles, the total number of particles decreases at low and medium loads but increases at high loads. In all cases, there is a shift of the particles towards smaller geometrical mean diameter, especially at high loads. The increase in nano-sized particles and the increase in NO(2) emission could have serious impact on human health.

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

Automotive Stirling Engine Development Program

NASA Technical Reports Server (NTRS)

Nightingale, N.; Ernst, W.; Richey, A.; Simetkosky, M.; Smith, G.; Antonelli, M. (Editor)

1983-01-01

Mod I engine testing and test results, the test of a Mod I engine in the United States, Mod I engine characterization and analysis, Mod I Transient Test Bed fuel economy, Mod I-A engine performance are discussed. Stirling engine reference engine manufacturing and reduced size studies, components and subsystems, and the study and test of low-cost casting alloys are also covered. The overall program philosophy is outlined, and data and results are presented.

Internationalizing professional codes in engineering.

PubMed

Harris, Charles E

2004-07-01

Professional engineering societies which are based in the United States, such as the American Society of Mechanical Engineers (ASME, now ASME International) are recognizing that their codes of ethics must apply to engineers working throughout the world. An examination of the ethical code of the ASME International shows that its provisions pose many problems of application, especially in societies outside the United States. In applying the codes effectively in the international environment, two principal issues must be addressed. First, some Culture Transcending Guidelines must be identified and justified. Nine such guidelines are identified Second, some methods for applying the codes to particular situations must be identified Three such methods are specification, balancing, and finding a creative middle way.

Development and Testing of an Experimental Mobile Instructional Facility for Applied Courses in Engineering Technology.

ERIC Educational Resources Information Center

Kleine, Louis W.

The experimental pilot project was conducted to determine whether students who take the laboratory phase of an engineering technology applied electricity course in a mobile laboratory at branch schools demonstrate proficiency comparable to students who take the applied electricity course in permanent facilities at the parent institution. The…

Enhancing fire safety at Hydro plants with dry transformers

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

Clemen, D.M.

Hydroelectric plant owners and engineers can use dry-type transformers to reduce fire hazards in auxiliary power systems. The decision to replace a liquid-immersed transformer with a dry-type product has a price: higher unit cost and a need to be more vigilant in detailing transformer specifications. But, whether the change affects only one failed transformer or is part of a plant rehabilitation project, the benefits in safety can be worth it. Voltages on hydroelectric plant auxiliary power systems can range from a 20 kV medium-voltage system to the normal 480-208/120 V low-voltage system. Dry transformers typically are used in such systemsmore » to reduce the fire hazard present with liquid-filled transformers. For a hydro plant owner or engineer seeking alternatives to liquid-filled transformers, there are two main kinds of dry-type transformers to consider: vacuum pressure impregnated (VPI) and cast coil epoxy resin. VPI transformers normally are manufactured in sizes up to 6,000 kVA with primary voltage ratings up to 20 kV. Cast coil transformers can be made in sizes from 75 to 10,000 kVA, with primary voltage ratings up to 34,500 V. Although the same transformer theory applies to dry transformers as to liquid-filled units, the cooling medium, air, required different temperature rise ratings, dielectric tests, and construction techniques to ensure reliability. Consequently, the factory and field tests for dry units are established by a separate set of American National Standards Institute (ANSI)/Institute of Electrical and Electronics Engineers (IEEE) standards. Cast coil transformers have several important advantages over VPI units.« less

HiDi: an efficient reverse engineering schema for large-scale dynamic regulatory network reconstruction using adaptive differentiation.

PubMed

Deng, Yue; Zenil, Hector; Tegnér, Jesper; Kiani, Narsis A

2017-12-15

The use of differential equations (ODE) is one of the most promising approaches to network inference. The success of ODE-based approaches has, however, been limited, due to the difficulty in estimating parameters and by their lack of scalability. Here, we introduce a novel method and pipeline to reverse engineer gene regulatory networks from gene expression of time series and perturbation data based upon an improvement on the calculation scheme of the derivatives and a pre-filtration step to reduce the number of possible links. The method introduces a linear differential equation model with adaptive numerical differentiation that is scalable to extremely large regulatory networks. We demonstrate the ability of this method to outperform current state-of-the-art methods applied to experimental and synthetic data using test data from the DREAM4 and DREAM5 challenges. Our method displays greater accuracy and scalability. We benchmark the performance of the pipeline with respect to dataset size and levels of noise. We show that the computation time is linear over various network sizes. The Matlab code of the HiDi implementation is available at: www.complexitycalculator.com/HiDiScript.zip. hzenilc@gmail.com or narsis.kiani@ki.se. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Analysis of the design and economics of molten carbonate fuel cell tri-generation systems providing heat and power for commercial buildings and H2 for FC vehicles

NASA Astrophysics Data System (ADS)

Li, Xuping; Ogden, Joan; Yang, Christopher

2013-11-01

This study models the operation of molten carbonate fuel cell (MCFC) tri-generation systems for “big box” store businesses that combine grocery and retail business, and sometimes gasoline retail. Efficiency accounting methods and parameters for MCFC tri-generation systems have been developed. Interdisciplinary analysis and an engineering/economic model were applied for evaluating the technical, economic, and environmental performance of distributed MCFC tri-generation systems, and for exploring the optimal system design. Model results show that tri-generation is economically competitive with the conventional system, in which the stores purchase grid electricity and NG for heat, and sell gasoline fuel. The results are robust based on sensitivity analysis considering the uncertainty in energy prices and capital cost. Varying system sizes with base case engineering inputs, energy prices, and cost assumptions, it is found that there is a clear tradeoff between the portion of electricity demand covered and the capital cost increase of bigger system size. MCFC Tri-generation technology provides lower emission electricity, heat, and H2 fuel. With NG as feedstock the CO2 emission can be reduced by 10%-43.6%, depending on how the grid electricity is generated. With renewable methane as feedstock CO2 emission can be further reduced to near zero.

Appling grain boundary engineering to Alloy 690 tube for enhancing intergranular corrosion resistance

NASA Astrophysics Data System (ADS)

Xia, Shuang; Li, Hui; Liu, Ting Guang; Zhou, Bang Xin

2011-09-01

The feasibility of applying the grain boundary engineering (GBE) processing to Alloy 690 tube manufacturing for improving the intergranular corrosion resistance was studied. Through small amount of deformation by cold drawing using a draw-bench on a production line and subsequent short time annealing at high temperature, the proportion of low Σ coincidence site lattice (CSL) grain boundaries of the Alloy 690 tube can be enhanced to about 75% which mainly were of Σ3 n ( n = 1, 2, 3, …) type. In this case, the grain boundary network (GBN) was featured by the formation of highly twinned large size grain-clusters produced by multiple twinning during recrystallization. All of the grains inside this kind of cluster had Σ3 n mutual misorientations, and hence all the boundaries inside the cluster were of Σ3 n type and formed many interconnected Σ3 n type triple junctions. The weight losses due to grain dropping during intergranular corrosion for the samples with the modified GBN were much less than that with conventional microstructure. Based on the characterization by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) technique, it was shown that the highly twinned large size grain-cluster microstructure played a key role in enhancing the intergranular corrosion resistance: (1) the large grain-cluster can arrest the penetration of intergranular corrosion; (2) the large grain-cluster can protect the underlying microstructure.

78 FR 70216 - Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-25

... Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines AGENCY: Federal Aviation... all Thielert Aircraft Engines GmbH TAE 125-01 reciprocating engines. This AD requires applying sealant... directive (AD): 2013-24-06 Thielert Aircraft Engines GmbH: Amendment 39-17680; Docket No. FAA-2013-0561...

40 CFR 1039.101 - What exhaust emission standards must my engines meet after the 2014 model year?

Code of Federal Regulations, 2010 CFR

2010-07-01

... my engines meet after the 2014 model year? 1039.101 Section 1039.101 Protection of Environment... emission standards must my engines meet after the 2014 model year? The exhaust emission standards of this section apply after the 2014 model year. Certain of these standards also apply for model year 2014 and...

Defining Gas Turbine Engine Performance Requirements for the Large Civil TiltRotor (LCTR2)

NASA Technical Reports Server (NTRS)

Snyder, Christopher A.

2013-01-01

Defining specific engine requirements is a critical part of identifying technologies and operational models for potential future rotary wing vehicles. NASA's Fundamental Aeronautics Program, Subsonic Rotary Wing Project has identified the Large Civil TiltRotor (LCTR) as the configuration to best meet technology goals. This notional vehicle concept has evolved with more clearly defined mission and operational requirements to the LCTR-iteration 2 (LCTR2). This paper reports on efforts to further review and refine the LCTR2 analyses to ascertain specific engine requirements and propulsion sizing criteria. The baseline mission and other design or operational requirements are reviewed. Analysis tools are described to help understand their interactions and underlying assumptions. Various design and operational conditions are presented and explained for their contribution to defining operational and engine requirements. These identified engine requirements are discussed to suggest which are most critical to the engine sizing and operation. The most-critical engine requirements are compared to in-house NASA engine simulations to try to ascertain which operational requirements define engine requirements versus points within the available engine operational capability. Finally, results are summarized with suggestions for future efforts to improve analysis capabilities, and better define and refine mission and operational requirements.

Center for Urban Transportation Studies | College of Engineering & Applied

Science.gov Websites

Engineering of the College of Engineering and Applied Science as well as with the faculty at UW-Madison, UW Science A B C D E F G H I J K L M N O P Q R S T U V W X Y Z D2L PAWS Email My UW-System About UWM Jobs D2L PAWS Email My UW-System University of Wisconsin-Milwaukee College ofEngineering &

Field Evaluation of Six Protective Coatings Applied to T56 Turbines after 1500 Hours Engine Use

DTIC Science & Technology

1991-06-01

Six Coating Systems On First-stage Gas Turbine Blades In The Engines of a Long-Range Maritime Patrol Aircraft ", Surface and Coating Technology, 36...based coatings. They were applied to the first-stage turbine blades in the engines of two long range maritime patrol aircraft operated by the Royal...incorrect. These differently coated turbine - blades have in fact seen 1500 hours service in a T56 engine . The title and further reference in the text should

Sea level side loads in high-area-ratio rocket engines

NASA Technical Reports Server (NTRS)

Nave, L. H.; Coffey, G. A.

1973-01-01

An empirical separation and side load model to obtain applied aerodynamic loads has been developed based on data obtained from full-scale J-2S (265K-pound-thrust engine with an area ratio of 40:1) engine and model testing. Experimental data include visual observations of the separation patterns that show the dynamic nature of the separation phenomenon. Comparisons between measured and applied side loads are made. Correlations relating the separation location to the applied side loads and the methods used to determine the separation location are given.

Durability Testing of Tank Track Rubber Compounds under Cyclic Loading

DTIC Science & Technology

1987-10-15

depiction of time-to-failure vs applied ( engineering ) stress for 15TP-14AX rubber compounds in creep experiments at 23"C. (After McKenna (1...behavior of the 15TP-14AX rubber was carried out at 23, 75, 125 and 175 OC. The logarithm of the time to failure vs. the applied ( engineering ) stress is...4 3I. I I 5 10 15 a/MPa Figure 3-7 Semilogarith±ic depiction of time-to--failure vs applied ( engineering ) stress for 15TP-14AX rubber compounds in

Analysis of Performance of Jet Engine from Characteristics of Components II : Interaction of Components as Determined from Engine Operation

NASA Technical Reports Server (NTRS)

Goldstein, Arthur W; Alpert, Sumner; Beede, William; Kovach, Karl

1949-01-01

In order to understand the operation and the interaction of jet-engine components during engine operation and to determine how component characteristics may be used to compute engine performance, a method to analyze and to estimate performance of such engines was devised and applied to the study of the characteristics of a research turbojet engine built for this investigation. An attempt was made to correlate turbine performance obtained from engine experiments with that obtained by the simpler procedure of separately calibrating the turbine with cold air as a driving fluid in order to investigate the applicability of component calibration. The system of analysis was also applied to prediction of the engine and component performance with assumed modifications of the burner and bearing characteristics, to prediction of component and engine operation during engine acceleration, and to estimates of the performance of the engine and the components when the exhaust gas was used to drive a power turbine.

Probabilistic Analysis Techniques Applied to Complex Spacecraft Power System Modeling

NASA Technical Reports Server (NTRS)

Hojnicki, Jeffrey S.; Rusick, Jeffrey J.

2005-01-01

Electric power system performance predictions are critical to spacecraft, such as the International Space Station (ISS), to ensure that sufficient power is available to support all the spacecraft s power needs. In the case of the ISS power system, analyses to date have been deterministic, meaning that each analysis produces a single-valued result for power capability because of the complexity and large size of the model. As a result, the deterministic ISS analyses did not account for the sensitivity of the power capability to uncertainties in model input variables. Over the last 10 years, the NASA Glenn Research Center has developed advanced, computationally fast, probabilistic analysis techniques and successfully applied them to large (thousands of nodes) complex structural analysis models. These same techniques were recently applied to large, complex ISS power system models. This new application enables probabilistic power analyses that account for input uncertainties and produce results that include variations caused by these uncertainties. Specifically, N&R Engineering, under contract to NASA, integrated these advanced probabilistic techniques with Glenn s internationally recognized ISS power system model, System Power Analysis for Capability Evaluation (SPACE).

Advanced Vacuum Plasma Spray (VPS) for a Robust, Longlife and Safe Space Shuttle Main Engine (SSME)

NASA Technical Reports Server (NTRS)

Holmes, Richard R.; Elam, Sandra K.; McKechnie, Timothy N.; Power, Christopher A.

2010-01-01

In 1984, the Vacuum Plasma Spray Lab was built at NASA/Marshall Space Flight Center for applying durable, protective coatings to turbine blades for the space shuttle main engine (SSME) high pressure fuel turbopump. Existing turbine blades were cracking and breaking off after five hot fire tests while VPS coated turbine blades showed no wear or cracking after 40 hot fire tests. Following that, a major manufacturing problem of copper coatings peeling off the SSME Titanium Main Fuel Valve Housing was corrected with a tenacious VPS copper coating. A patented VPS process utilizing Functional Gradient Material (FGM) application was developed to build ceramic lined metallic cartridges for space furnace experiments, safely containing gallium arsenide at 1260 degrees centigrade. The VPS/FGM process was then translated to build robust, long life, liquid rocket combustion chambers for the space shuttle main engine. A 5K (5,000 Lb. thrust) thruster with the VPS/FGM protective coating experienced 220 hot firing tests in pristine condition with no wear compared to the SSME which showed blanching (surface pulverization) and cooling channel cracks in less than 30 of the same hot firing tests. After 35 of the hot firing tests, the injector face plates disintegrated. The VPS/FGM process was then applied to spraying protective thermal barrier coatings on the face plates which showed 50% cooler operating temperature, with no wear after 50 hot fire tests. Cooling channels were closed out in two weeks, compared to one year for the SSME. Working up the TRL (Technology Readiness Level) to establish the VPS/FGM process as viable technology, a 40K thruster was built and is currently being tested. Proposed is to build a J-2X size liquid rocket engine as the final step in establishing the VPS/FGM process TRL for space flight.

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.

Effect of open channel filter on particle emissions of modern diesel engine.

PubMed

Heikkilä, Juha; Rönkkö, Topi; Lähde, Tero; Lemmetty, Mikko; Arffman, Anssi; Virtanen, Annele; Keskinen, Jorma; Pirjola, Liisa; Rothe, Dieter

2009-10-01

Particle emissions of modern diesel engines are of a particular interest because of their negative health effects. The special interest is in nanosized solid particles. The effect of an open channel filter on particle emissions of a modern heavy-duty diesel engine (MAN D2066 LF31, model year 2006) was studied. Here, the authors show that the open channel filter made from metal screen efficiently reduced the number of the smallest particles and, notably, the number and mass concentration of soot particles. The filter used in this study reached 78% particle mass reduction over the European Steady Cycle. Considering the size-segregated number concentration reduction, the collection efficiency was over 95% for particles smaller than 10 nm. The diffusion is the dominant collection mechanism in small particle sizes, thus the collection efficiency decreased as particle size increased, attaining 50% at 100 nm. The overall particle number reduction was 66-99%, and for accumulation-mode particles the number concentration reduction was 62-69%, both depending on the engine load.

The Effects of Topographical Patterns and Sizes on Neural Stem Cell Behavior

PubMed Central

Qi, Lin; Li, Ning; Huang, Rong; Song, Qin; Wang, Long; Zhang, Qi; Su, Ruigong; Kong, Tao; Tang, Mingliang; Cheng, Guosheng

2013-01-01

Engineered topographical manipulation, a paralleling approach with conventional biochemical cues, has recently attracted the growing interests in utilizations to control stem cell fate. In this study, effects of topological parameters, pattern and size are emphasized on the proliferation and differentiation of adult neural stem cells (ANSCs). We fabricate micro-scale topographical Si wafers with two different feature sizes. These topographical patterns present linear micro-pattern (LMP), circular micro-pattern (CMP) and dot micro-pattern (DMP). The results show that the three topography substrates are suitable for ANSC growth, while they all depress ANSC proliferation when compared to non-patterned substrates (control). Meanwhile, LMP and CMP with two feature sizes can both significantly enhance ANSC differentiation to neurons compared to control. The smaller the feature size is, the better upregulation applies to ANSC for the differentiated neurons. The underlying mechanisms of topography-enhanced neuronal differentiation are further revealed by directing suppression of mitogen-activated protein kinase/extracellular signaling-regulated kinase (MAPK/Erk) signaling pathway in ANSC using U0126, known to inhibit the activation of Erk. The statistical results suggest MAPK/Erk pathway is partially involved in topography-induced differentiation. These observations provide a better understanding on the different roles of topographical cues on stem cell behavior, especially on the selective differentiation, and facilitate to advance the field of stem cell therapy. PMID:23527077

Characterization of silver nanoparticles using flow-field flow fractionation interfaced to inductively coupled plasma mass spectrometry.

PubMed

Poda, A R; Bednar, A J; Kennedy, A J; Harmon, A; Hull, M; Mitrano, D M; Ranville, J F; Steevens, J

2011-07-08

The ability to detect and identify the physiochemical form of contaminants in the environment is important for degradation, fate and transport, and toxicity studies. This is particularly true of nanomaterials that exist as discrete particles rather than dissolved or sorbed contaminant molecules in the environment. Nanoparticles will tend to agglomerate or dissolve, based on solution chemistry, which will drastically affect their environmental properties. The current study investigates the use of field flow fractionation (FFF) interfaced to inductively coupled plasma-mass spectrometry (ICP-MS) as a sensitive and selective method for detection and characterization of silver nanoparticles. Transmission electron microscopy (TEM) is used to verify the morphology and primary particle size and size distribution of precisely engineered silver nanoparticles. Subsequently, the hydrodynamic size measurements by FFF are compared to dynamic light scattering (DLS) to verify the accuracy of the size determination. Additionally, the sensitivity of the ICP-MS detector is demonstrated by fractionation of μg/L concentrations of mixed silver nanoparticle standards. The technique has been applied to nanoparticle suspensions prior to use in toxicity studies, and post-exposure biological tissue analysis. Silver nanoparticles extracted from tissues of the sediment-dwelling, freshwater oligochaete Lumbriculus variegatus increased in size from approximately 31-46nm, indicating a significant change in the nanoparticle characteristics during exposure. Published by Elsevier B.V.

Internet Search Engines - Fluctuations in Document Accessibility.

ERIC Educational Resources Information Center

Mettrop, Wouter; Nieuwenhuysen, Paul

2001-01-01

Reports an empirical investigation of the consistency of retrieval through Internet search engines. Evaluates 13 engines: AltaVista, EuroFerret, Excite, HotBot, InfoSeek, Lycos, MSN, NorthernLight, Snap, WebCrawler, and three national Dutch engines: Ilse, Search.nl and Vindex. The focus is on a characteristic related to size: the degree of…

Integrating Science and Engineering to Implement Evidence-Based Practices in Health Care Settings

PubMed Central

Wu, Shinyi; Duan, Naihua; Wisdom, Jennifer P.; Kravitz, Richard L.; Owen, Richard R.; Sullivan, Greer; Wu, Albert W.; Di Capua, Paul; Hoagwood, Kimberly Eaton

2015-01-01

Integrating two distinct and complementary paradigms, science and engineering, may produce more effective outcomes for the implementation of evidence-based practices in health care settings. Science formalizes and tests innovations, whereas engineering customizes and optimizes how the innovation is applied tailoring to accommodate local conditions. Together they may accelerate the creation of an evidence-based healthcare system that works effectively in specific health care settings. We give examples of applying engineering methods for better quality, more efficient, and safer implementation of clinical practices, medical devices, and health services systems. A specific example was applying systems engineering design that orchestrated people, process, data, decision-making, and communication through a technology application to implement evidence-based depression care among low-income patients with diabetes. We recommend that leading journals recognize the fundamental role of engineering in implementation research, to improve understanding of design elements that create a better fit between program elements and local context. PMID:25217100

Statistical shear lag model - unraveling the size effect in hierarchical composites.

PubMed

Wei, Xiaoding; Filleter, Tobin; Espinosa, Horacio D

2015-05-01

Numerous experimental and computational studies have established that the hierarchical structures encountered in natural materials, such as the brick-and-mortar structure observed in sea shells, are essential for achieving defect tolerance. Due to this hierarchy, the mechanical properties of natural materials have a different size dependence compared to that of typical engineered materials. This study aimed to explore size effects on the strength of bio-inspired staggered hierarchical composites and to define the influence of the geometry of constituents in their outstanding defect tolerance capability. A statistical shear lag model is derived by extending the classical shear lag model to account for the statistics of the constituents' strength. A general solution emerges from rigorous mathematical derivations, unifying the various empirical formulations for the fundamental link length used in previous statistical models. The model shows that the staggered arrangement of constituents grants composites a unique size effect on mechanical strength in contrast to homogenous continuous materials. The model is applied to hierarchical yarns consisting of double-walled carbon nanotube bundles to assess its predictive capabilities for novel synthetic materials. Interestingly, the model predicts that yarn gauge length does not significantly influence the yarn strength, in close agreement with experimental observations. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Microwave Tissue Ablation: Biophysics, Technology and Applications

PubMed Central

2010-01-01

Microwave ablation is an emerging treatment option for many cancers, cardiac arrhythmias and other medical conditions. During treatment, microwaves are applied directly to tissues to produce rapid temperature elevations sufficient to produce immediate coagulative necrosis. The engineering design criteria for each application differ, with individual consideration for factors such as desired ablation zone size, treatment duration, and procedural invasiveness. Recent technological developments in applicator cooling, power control and system optimization for specific applications promise to increase the utilization of microwave ablation in the future. This article will review the basic biophysics of microwave tissue heating, provide an overview of the design and operation of current equipment, and outline areas for future research for microwave ablation. PMID:21175404

Analysis of survival data from telemetry projects

USGS Publications Warehouse

Bunck, C.M.; Winterstein, S.R.; Pollock, K.H.

1985-01-01

Telemetry techniques can be used to study the survival rates of animal populations and are particularly suitable for species or settings for which band recovery models are not. Statistical methods for estimating survival rates and parameters of survival distributions from observations of radio-tagged animals will be described. These methods have been applied to medical and engineering studies and to the study of nest success. Estimates and tests based on discrete models, originally introduced by Mayfield, and on continuous models, both parametric and nonparametric, will be described. Generalizations, including staggered entry of subjects into the study and identification of mortality factors will be considered. Additional discussion topics will include sample size considerations, relocation frequency for subjects, and use of covariates.

Ducted Fan Designs Lead to Potential New Vehicles

NASA Technical Reports Server (NTRS)

2010-01-01

In 1994, aerospace engineers Rob Bulaga and Mike Moshier formed Trek Aerospace Inc., based in Folsom, California, to develop personal air vehicles using a novel ducted fan design. The company relied on Ames Research Center for a great deal of testing, the results of which have provided greater lift, lowered weight, more power, and improved maneuverability. The technology has been applied to three models: the Dragonfly UMR-1, the Springtail EFV, and the OVIWUN, a small-scale version that is for sale through the company's Web site. It is safer than a manned vehicle, and its size makes it relatively difficult for it to damage itself during test flights the way a larger mass, faster craft could.

LETTER TO THE EDITOR: Exhaustive search for low-autocorrelation binary sequences

NASA Astrophysics Data System (ADS)

Mertens, S.

1996-09-01

Binary sequences with low autocorrelations are important in communication engineering and in statistical mechanics as ground states of the Bernasconi model. Computer searches are the main tool in the construction of such sequences. Owing to the exponential size 0305-4470/29/18/005/img1 of the configuration space, exhaustive searches are limited to short sequences. We discuss an exhaustive search algorithm with run-time characteristic 0305-4470/29/18/005/img2 and apply it to compile a table of exact ground states of the Bernasconi model up to N = 48. The data suggest F > 9 for the optimal merit factor in the limit 0305-4470/29/18/005/img3.

Biomedical Engineering | Classification | College of Engineering & Applied

Science.gov Websites

Engineering, Biomedical Engineering(414) 229-6614wjchang@uwm.eduEng & Math Sciences 1113 profile photo Malkoc, Ph.D.Visiting Assistant ProfessorBiomedical Engineering414-229-6919malkoc@uwm.eduEng & Math Engineering / Electrical Engineering(414) 229-3327misra@uwm.eduEng & Math Sciences E-314 profile photo

Some Expected Characteristics of Lunar Dust: A Geological View Applied to Engineering

NASA Technical Reports Server (NTRS)

Street, Kenneth W.; Schrader, Christian M.; Rickman, Doug

2008-01-01

Compared to the Earth the geologic nature of the lunar regolith is quite distinct. Even though similar minerals exist on the Earth and Moon, they may have very different properties due to the absence of chemical modification in the lunar environment. The engineering properties of the lunar regolith reflect aspects of the parent rock and the consequences of hypervelocity meteor bombardment. On scales relevant to machinery and chemical processing for In-Situ Resource Utilization, ISRU (such as water production), the lunar regolith compositional range is much more restricted than terrestrial material. This fact impacts predictions of properties required by design engineers for constructing equipment for lunar use. In this paper two examples will be covered. 1) Abrasion is related to hardness and hardness is a commonly measured property for both minerals and engineering materials. Although different hardness scales are routinely employed for minerals and engineering materials, a significant amount of literature is available relating the two. As one example, we will discuss how to relate hardness to abrasion for the design of lunar equipment. We also indicate how abundant the various mineral phases are and typical size distributions for lunar regolith which will impact abrasive nature. 2) Mineral characteristics that may seem trivial to the non-geologist or material scientist may have significant bearing on ISRU processing technologies. As a second example we discuss the impact of traces of F-, Cl-, and OH-, H2O, CO2, and sulfur species which can radically alter melting points and the corrosive nature of reaction products thereby significantly changing bulk chemistry and associated processing technologies. For many engineering uses, a simulant s fidelity to bulk lunar regolith chemistry may be insufficient. Therefore, simulant users need to engage in continuing dialogue with simulant developers and geoscientists.

Some Expected Characteristics of Lunar Dust: A Geological View Applied to Engineering

NASA Technical Reports Server (NTRS)

Street, Kenneth W.; Schrader, Christian M.; Rickman, Doug

2008-01-01

Compared to the Earth the geologic nature of the lunar regolith is quite distinct. Even though similar minerals exist on the Earth and Moon, they may have very different properties due to the absence of chemical modification in the lunar environment. The engineering properties of the lunar regolith reflect aspects of the parent rock and the consequences of hypervelocity meteor bombardment. On scales relevant to machinery and chemical processing for In-Situ Resource Utilization, ISRU (such as water production), the lunar regolith compositional range is much more restricted than terrestrial material. This fact impacts predictions of properties required by design engineers for constructing equipment for lunar use. In this paper two examples will be covered. 1) Abrasion is related to hardness and hardness is a commonly measured property for both minerals and engineering materials. Although different hardness scales are routinely employed for minerals and engineering materials, a significant amount of literature is available relating the two. As one example, we will discuss how to relate hardness to abrasion for the design of lunar equipment. We also indicate how abundant the various mineral phases are and typical size distributions for lunar regolith which will impact abrasive nature. 2) Mineral characteristics that may seem trivial to the non-geologist or material scientist may have significant bearing on ISRU processing technologies. As a second example we discuss the impact of traces of fluoride, chloride, and hydroxide, water, carbon dioxide, and sulfur species which can radically alter melting points and the corrosive nature of reaction products thereby significantly changing bulk chemistry and associated processing technologies. For many engineering uses, a simulant's fidelity to bulk lunar regolith chemistry may be insufficient. Therefore, simulant users need to engage in continuing dialogue with simulant developers and geoscientists.

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.

77 FR 1009 - Airworthiness Directives; Turbomeca Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-09

... Directives; Turbomeca Turboshaft Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... the Federal Register. That AD applies to Turbomeca Arriel 1 series turboshaft engines. The AD number...: Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park...

Welding As Science: Applying Basic Engineering Principles to the Discipline

NASA Technical Reports Server (NTRS)

Nunes, A. C., Jr.

2010-01-01

This Technical Memorandum provides sample problems illustrating ways in which basic engineering science has been applied to the discipline of welding. Perhaps inferences may be drawn regarding optimal approaches to particular welding problems, as well as for the optimal education for welding engineers. Perhaps also some readers may be attracted to the science(s) of welding and may make worthwhile contributions to the discipline.

Combustion system CFD modeling at GE Aircraft Engines

NASA Technical Reports Server (NTRS)

Burrus, D.; Mongia, H.; Tolpadi, Anil K.; Correa, S.; Braaten, M.

1995-01-01

This viewgraph presentation discusses key features of current combustion system CFD modeling capabilities at GE Aircraft Engines provided by the CONCERT code; CONCERT development history; modeling applied for designing engine combustion systems; modeling applied to improve fundamental understanding; CONCERT3D results for current production combustors; CONCERT3D model of NASA/GE E3 combustor; HYBRID CONCERT CFD/Monte-Carlo modeling approach; and future modeling directions.

Combustion system CFD modeling at GE Aircraft Engines

NASA Astrophysics Data System (ADS)

Burrus, D.; Mongia, H.; Tolpadi, Anil K.; Correa, S.; Braaten, M.

1995-03-01

This viewgraph presentation discusses key features of current combustion system CFD modeling capabilities at GE Aircraft Engines provided by the CONCERT code; CONCERT development history; modeling applied for designing engine combustion systems; modeling applied to improve fundamental understanding; CONCERT3D results for current production combustors; CONCERT3D model of NASA/GE E3 combustor; HYBRID CONCERT CFD/Monte-Carlo modeling approach; and future modeling directions.

A Joint Venture Model for Teaching Required Courses in "Ethics and Engineering" to Engineering Students

ERIC Educational Resources Information Center

Zandvoort, H.; Van Hasselt, G. J.; Bonnet, J. A. B. A. F.

2008-01-01

We present our experience, spanning more than 10 years of teaching a course on "ethics and engineering" for a group of MSc programmes in applied sciences at Delft University of Technology. The course is taught by a team of teachers from the faculty of Applied Sciences and from the department of Philosophy of the Faculty of Technology,…

Turbulent Transport at High Reynolds Numbers in an Inertial Confinement Fusion Context

DTIC Science & Technology

2014-09-01

Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794 P . Rao1 Department of Applied Mathematics and Statistics...scales, 1Corresponding author. Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING...Engineering SEPTEMBER 2014, Vol. 136 / 091206-1Copyright VC 2014 by ASME Downloaded From: http://fluidsengineering.asmedigitalcollection.asme.org/ on

Characterization of manufactured TiO2 nanoparticles

NASA Astrophysics Data System (ADS)

Motzkus, C.; Macé, T.; Vaslin-Reimann, S.; Ausset, P.; Maillé, M.

2013-04-01

Technological advances in nanomaterials have allowed the development of new applications in industry, increasing the probability of finding airborne manufactured and engineered nano-objects in the workplace, as well as in ambient air. Scientific studies on health and environmental risks have indicated that airborne nano-objects in ambient air have potential adverse effects on the health of exposed workers and the general population. For regulatory purposes, ambient measurements of particulate matter are based on the determination of mass concentrations for PM10 and PM2.5, as regulated in the European Directive 2008/50/EC. However, this legislation is not suitable for airborne manufactured and engineered nano-objects. Parameters characterising ultrafine particles, such as particle number concentration and size distribution, are under consideration for future health-based legislation, to monitor workplaces and to control industrial processes. Currently, there are no existing regulations covering manufactured airborne nano-objects. There is therefore a clear, unaddressed need to focus on the toxicology and exposure assessment of nano-objects such as titanium dioxide (TiO2), which are manufactured and engineered in large quantities in industry. To perform reliable toxicology studies it is necessary to determine the relevant characteristics of nano-objects, such as morphology, surface area, agglomeration, chemical composition, particle size and concentration, by applying traceable methods. Manufacturing of nanomaterials, and their use in industrial applications, also require traceable characterisation of the nanomaterials, particularly for quality control of the process. The present study arises from the OECD WPMN sponsorship programme, supported by the French Agency for Environmental and Occupational Health Safety (ANSES), in order to develop analytical methods for the characterization of TiO2 nanoparticles in size and count size distribution, based on different techniques to characterize five different manufactured TiO2 nanoparticles. In this study, different measurement techniques have been implemented: Transmission Electron Microscopy (TEM), Scanning Mobility Particle Sizer (SMPS) and Aerodynamic Particle Sizer (APS). The TEM results lead to a relatively good agreement between data from the manufacturer and our characterizations of primary particle size. With regard to the dustiness, the results show a strong presence of agglomerates / aggregates of primary particles and a significant presence of emitted airborne nanoparticles with a diameter below 100 nm (composed of isolated primary particles and small aggregates / agglomerates formed from a few primary particles): the number proportion of these particles varies from 0 to 44 % in the measurement range 14-360 nm depending on the types of powders and corrections of measurements.

Automotive Stirling engine development program

NASA Technical Reports Server (NTRS)

Nightingale, N.; Ernst, W.; Richey, A.; Simetkosky, M.; Smith, G.; Rohdenburg, C.; Vatsky, A.; Antonelli, M. (Editor)

1983-01-01

Activities performed on Mod I engine testing and test results, testing of the Mod I engine in the United States, Mod I engine characterization and analyses, Mod I Transient Test Bed fuel economy, upgraded Mod I performance and testing, Stirling engine reference engine manufacturing and reduced size studied, components and subsystems, and the study and test of low cost casting alloys are summarized. The overall program philosophy is outlined, and data and results are presented.

Advanced general aviation engine/airframe integration study

NASA Technical Reports Server (NTRS)

Zmroczek, L. A.

1982-01-01

A comparison of the in-airframe performance and efficiency of the advanced engine concepts is presented. The results indicate that the proposed advanced engines can significantly improve the performance and economy of general aviation airplanes. The engine found to be most promising is the highly advanced version of a rotary combustion (Wankel) engine. The low weight and fuel consumption of this engine, as well as its small size, make it suited for aircraft use.

40 CFR 1027.115 - What special provisions apply for certification related to nonroad and stationary engines?

Code of Federal Regulations, 2010 CFR

2010-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS FEES FOR ENGINE, VEHICLE, AND EQUIPMENT... relates to emission standards that apply only in California, you must pay the same fee identified for...

40 CFR 1027.115 - What special provisions apply for certification related to nonroad and stationary engines?

Code of Federal Regulations, 2014 CFR

2014-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS FEES FOR ENGINE, VEHICLE, AND EQUIPMENT... relates to emission standards that apply only in California, you must pay the same fee identified for...

40 CFR 1027.115 - What special provisions apply for certification related to nonroad and stationary engines?

Code of Federal Regulations, 2011 CFR

2011-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS FEES FOR ENGINE, VEHICLE, AND EQUIPMENT... relates to emission standards that apply only in California, you must pay the same fee identified for...

40 CFR 1027.115 - What special provisions apply for certification related to nonroad and stationary engines?

Code of Federal Regulations, 2012 CFR

2012-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS FEES FOR ENGINE, VEHICLE, AND EQUIPMENT... relates to emission standards that apply only in California, you must pay the same fee identified for...

40 CFR 1027.115 - What special provisions apply for certification related to nonroad and stationary engines?

Code of Federal Regulations, 2013 CFR

2013-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS FEES FOR ENGINE, VEHICLE, AND EQUIPMENT... relates to emission standards that apply only in California, you must pay the same fee identified for...

23 CFR 620.202 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS ENGINEERING Relinquishment of Highway Facilities § 620.202 Applicability. The provisions of this subpart apply to highway... a project. The provisions of this subpart apply only to relinquishment of facilities for continued...

23 CFR 620.202 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS ENGINEERING Relinquishment of Highway Facilities § 620.202 Applicability. The provisions of this subpart apply to highway... a project. The provisions of this subpart apply only to relinquishment of facilities for continued...

23 CFR 620.202 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS ENGINEERING Relinquishment of Highway Facilities § 620.202 Applicability. The provisions of this subpart apply to highway... a project. The provisions of this subpart apply only to relinquishment of facilities for continued...

40 CFR 86.347-79 - Alternative calculations for diesel engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures § 86.347-79 Alternative calculations for diesel engines. (a) This section applies to Diesel engines only. Gasoline-fueled engines must use the calculations in § 86.345. (b) For Diesel engines, the...

40 CFR 86.347-79 - Alternative calculations for diesel engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures § 86.347-79 Alternative calculations for diesel engines. (a) This section applies to Diesel engines only. Gasoline-fueled engines must use the calculations in § 86.345. (b) For Diesel engines, the...

Micro/nano-particles and Cells: Manipulation, Transport, and Self-assembly

DTIC Science & Technology

2014-10-23

SECURITY CLASSIFICATION OF: Technologies that control nano- and micron- sized inert as well as biological materials are crucial to realizing engineered...that control nano- and micron- sized inert as well as biological materials are crucial to realizing engineered systems that can assemble, transport, and...nano-scale particles offer several advantages as building blocks of artificial materials . The relative ease of modifying their charge states

Advanced Subsonic Airplane Design and Economic Studies

NASA Technical Reports Server (NTRS)

Liebeck, Robert H.; Andrastek, Donald A.; Chau, Johnny; Girvin, Raquel; Lyon, Roger; Rawdon, Blaine K.; Scott, Paul W.; Wright, Robert A.

1995-01-01

A study was made to examine the effect of advanced technology engines on the performance of subsonic airplanes and provide a vision of the potential which these advanced engines offered. The year 2005 was selected as the entry-into-service (EIS) date for engine/airframe combination. A set of four airplane classes (passenger and design range combinations) that were envisioned to span the needs for the 2005 EIS period were defined. The airframes for all classes were designed and sized using 2005 EIS advanced technology. Two airplanes were designed and sized for each class: one using current technology (1995) engines to provide a baseline, and one using advanced technology (2005) engines. The resulting engine/airframe combinations were compared and evaluated on the basis on sensitivity to basic engine performance parameters (e.g. SFC and engine weight) as well as DOC+I. The advanced technology engines provided significant reductions in fuel burn, weight, and wing area. Average values were as follows: reduction in fuel burn = 18%, reduction in wing area = 7%, and reduction in TOGW = 9%. Average DOC+I reduction was 3.5% using the pricing model based on payload-range index and 5% using the pricing model based on airframe weight. Noise and emissions were not considered.

LOX/Hydrogen Coaxial Injector Atomization Test Program

NASA Technical Reports Server (NTRS)

Zaller, M.

1990-01-01

Quantitative information about the atomization of injector sprays is needed to improve the accuracy of computational models that predict the performance and stability margin of liquid propellant rocket engines. To obtain this data, a facility for the study of spray atomization is being established at NASA-Lewis to determine the drop size and velocity distributions occurring in vaporizing liquid sprays at supercritical pressures. Hardware configuration and test conditions are selected to make the cold flow simulant testing correspond as closely as possible to conditions in liquid oxygen (LOX)/gaseous H2 rocket engines. Drop size correlations from the literature, developed for liquid/gas coaxial injector geometries, are used to make drop size predictions for LOX/H2 coaxial injectors. The mean drop size predictions for a single element coaxial injector range from 0.1 to 2000 microns, emphasizing the need for additional studies of the atomization process in LOX/H2 engines. Selection of cold flow simulants, measured techniques, and hardware for LOX/H2 atomization simulations are discussed.

Towards the Development and Validation of a Global Field Size and Irrigation Map using Crowdsourcing, Mobile Apps and Google Earth Engine in support of GEOGLAM

NASA Astrophysics Data System (ADS)

Fritz, S.; Nordling, J.; See, L. M.; McCallum, I.; Perger, C.; Becker-Reshef, I.; Mucher, S.; Bydekerke, L.; Havlik, P.; Kraxner, F.; Obersteiner, M.

2014-12-01

The International Institute for Applied Systems Analysis (IIASA) has developed a global cropland extent map, which supports the monitoring and assessment activities of GEOGLAM (Group on Earth Observations Global Agricultural Monitoring Initiative). Through the European-funded SIGMA (Stimulating Innovation for Global Monitoring of Agriculture and its Impact on the Environment in support of GEOGLAM) project, IIASA is continuing to support GEOGLAM by providing cropland projections in the future and modelling environmental impacts on agriculture under various scenarios. In addition, IIASA is focusing on two specific elements within SIGMA: the development of a global field size and irrigation map; and mobile app development for in-situ data collection and validation of remotely-sensed products. Cropland field size is a very useful indicator for agricultural monitoring yet the information we have at a global scale is currently very limited. IIASA has already created a global map of field size at a 1 km resolution using crowdsourced data from Geo-Wiki as a first approximation. Using automatic classification of Landsat imagery and algorithms contained within Google Earth Engine, initial experimentation has shown that circular fields and landscape structures can easily be extracted. Not only will this contribute to improving the global map of field size, it can also be used to create a global map that contains a large proportion of the world's irrigated areas, which will be another useful contribution to GEOGLAM. The field size map will also be used to stratify and develop a global crop map in SIGMA. Mobile app development in support of in-situ data collection is another area where IIASA is currently working. An Android app has been built using the Open Data Toolkit (ODK) and extended further with spatial mapping capabilities called GeoODK. The app allows users to collect data on different crop types and delineate fields on the ground, which can be used to validate the field size map. The app can also cache map data so that high resolution satellite imagery and reference data from the users can be viewed in the field without the need for an internet connection. This app will be used for calibration and validation of the data products in SIGMA, e.g. data collection at JECAM (Joint Experiment of Crop Assessment and Monitoring) sites.

Highly stretchable HA/SA hydrogels for tissue engineering.

PubMed

Zhu, Chengcheng; Yang, Rui; Hua, Xiaobin; Chen, Hong; Xu, Jumei; Wu, Rile; Cen, Lian

2018-04-01

A highly stretchable hyaluronic acid (HA)/sodium alginate (SA) hydrogel was developed in this study based on an interpenetrating polymer network. HA/SA hydrogels were prepared by mixing two polysaccharides followed by covalent crosslinking via epoxy groups on HA molecules and ionic crosslinking via divalent ions on SA chains sequentially. The effect of HA/SA ratio on the pore size and distribution, swelling ratio, elongation and rheological properties as well as protein loading and release properties of HA/SA hydrogels was explored. Moreover, a surface modification method, layer-by-layer (LBL) assembly technique, was applied to modify the hydrogel to evaluate the hydrogel's tenability in varying biological performance. It was then shown that the hydrogels had the pore sizes ranging from 100 to 50 μm. With the increase in SA content of the resulting hydrogels, the pore size, swelling ratio, and storage modulus (G') and loss modulus (G″) of the hydrogel all decreased, whereas the in vitro bulk weight loss was fastened. Moreover, elongation at break (EB) value increased first, reached a peak value and then decreased, that is HA8/SA1 (HA:SA = 8:1) had the highest EB value of 417%. This hydrogel could retain 33.2% of the pre-loaded protein even after 72 h, which could be further attenuated when LBL was used to shell the hydrogel. The growth of fibroblasts on HA8/SA1 hydrogel gave preliminary assessment on its suitability as a cellular carrier, while the LBL modified HA8/SA1 hydrogel also favored the anchoring of keratinocytes, further enhancing its cell carrier role for tissue regeneration, especially skin engineering.

Monocular display unit for 3D display with correct depth perception

NASA Astrophysics Data System (ADS)

Sakamoto, Kunio; Hosomi, Takashi

2009-11-01

A study of virtual-reality system has been popular and its technology has been applied to medical engineering, educational engineering, a CAD/CAM system and so on. The 3D imaging display system has two types in the presentation method; one is a 3-D display system using a special glasses and the other is the monitor system requiring no special glasses. A liquid crystal display (LCD) recently comes into common use. It is possible for this display unit to provide the same size of displaying area as the image screen on the panel. A display system requiring no special glasses is useful for a 3D TV monitor, but this system has demerit such that the size of a monitor restricts the visual field for displaying images. Thus the conventional display can show only one screen, but it is impossible to enlarge the size of a screen, for example twice. To enlarge the display area, the authors have developed an enlarging method of display area using a mirror. Our extension method enables the observers to show the virtual image plane and to enlarge a screen area twice. In the developed display unit, we made use of an image separating technique using polarized glasses, a parallax barrier or a lenticular lens screen for 3D imaging. The mirror can generate the virtual image plane and it enlarges a screen area twice. Meanwhile the 3D display system using special glasses can also display virtual images over a wide area. In this paper, we present a monocular 3D vision system with accommodation mechanism, which is useful function for perceiving depth.

Testing exposure of a jet engine to a dilute volcanic-ash cloud

NASA Astrophysics Data System (ADS)

Guffanti, M.; Mastin, L. G.; Schneider, D. J.; Holliday, C. R.; Murray, J. J.

2013-12-01

An experiment to test the effects of volcanic-ash ingestion by a jet engine is being planned for 2014 by a consortium of U.S. Government agencies and engine manufacturers, under the auspices of NASA's Vehicle Integrated Propulsion Research Program. The experiment, using a 757-type engine, will be an on-ground, on-wing test carried out at Edwards Air Force Base, California. The experiment will involve the use of advanced jet-engine sensor technology for detecting and diagnosing engine health. A primary test objective is to determine the effect on the engine of many hours of exposure to ash concentrations (1 and 10 mg/cu m) representative of ash clouds many 100's to >1000 km from a volcanic source, an aviation environment of great interest since the 2010 Eyjafjallajökull, Iceland, eruption. A natural volcanic ash will be used; candidate sources are being evaluated. Data from previous ash/aircraft encounters, as well as published airborne measurements of the Eyjafjallajökull ash cloud, suggest the ash used should be composed primarily of glassy particles of andesitic to rhyolitic composition (SiO2 of 57-77%), with some mineral crystals, and a few tens of microns in size. Collected ash will be commercially processed less than 63 microns in size with the expectation that the ash particles will be further pulverized to smaller sizes in the engine during the test. For a nominally planned 80 hour test at multiple ash-concentration levels, the test will require roughly 500 kg of processed (appropriately sized) ash to be introduced into the engine core. Although volcanic ash clouds commonly contain volcanic gases such as sulfur dioxide, testing will not include volcanic gas or aerosol interactions as these present complex processes beyond the scope of the planned experiment. The viscous behavior of ash particles in the engine is a key issue in the experiment. The small glassy ash particles are expected to soften in the engine's hot combustion chamber, then stick to cooler parts of the turbine. Composition (primarily silica content) and dissolved water content, both of which affect the softening temperature of silicate melts, will be taken into account when evaluating candidate ash sources, although the practicalities of collecting, shipping, and processing a substantial amount of ash are a major decision factor in source selection.

Evaluation of engineering plastic for rollover protective structure (ROPS) mounting.

PubMed

Comer, R S; Ayers, P D; Liu, J

2007-04-01

Agriculture has one of the highest fatality rates of any industry in America. Tractor rollovers are a significant contributor to the high death rate. Rollover protective structures (ROPS) have helped lower these high fatality rates on full-size tractors. However, a large number of older tractors still do not use ROPS due to the difficulty of designing and creating a mounting structure. To help reduce this difficulty, engineering plastics were evaluated for use in a ROPS mounting structure on older tractors. The use of engineering plastics around axle housings could provide a uniform mounting configuration as well as lower costs for aftermarket ROPS. Various plastics were examined through shear testing, scale model testing, and compressive strength testing. Once a material was chosen based upon strength and cost, full-scale testing of the plastic's strength on axle housings was conducted. Finally, a mounting structure was tested in static ROPS tests, and field upset tests were performed in accordance with SAE Standard J2194. Initial tests revealed that the ROPS mounting structure and axle housing combination had higher torsional strength with less twisting than the axle housing alone. An engineering plastic ROPS mounting structure was easily successful in withstanding the forces applied during the static longitudinal and lateral ROPS tests. Field upset testing revealed that the mounting structure could withstand the impact loads seen during actual upsets without a failure. During both static testing and field upset testing, no permanent twisting of the mounting structure was found. Engineering plastic could therefore be a viable option for a universal ROPS mounting structure for older tractors.

Strain engineering of the elasticity and the Raman shift of nanostructured TiO2

NASA Astrophysics Data System (ADS)

Liu, X. J.; Pan, L. K.; Sun, Z.; Chen, Y. M.; Yang, X. X.; Yang, L. W.; Zhou, Z. F.; Sun, Chang Q.

2011-08-01

Correlation between the elastic modulus (B) and the Raman shift (Δω) of TiO2 and their responses to the variation of crystal size, applied pressure, and measuring temperature have been established as a function depending on the order, length, and energy of a representative bond for the entire specimen. In addition to the derived fundamental information of the atomic cohesive energy, binding energy density, Debye temperature and nonlinear compressibility, theoretical reproduction of the observations clarified that (i) the size effect arises from the under-coordination induced cohesive energy loss and the energy density gain in the surface up to skin depth; (ii) the thermally softened B and Δω results from bond expansion and bond weakening due to vibration; and, (iii) the mechanically stiffened B and Δω results from bond compression and bond strengthening due to mechanical work hardening. With the developed premise, one can predict the changing trends of the concerned properties with derivatives of quantitative information as such from any single measurement alone.

Soil mechanics: breaking ground.

PubMed

Einav, Itai

2007-12-15

In soil mechanics, student's models are classified as simple models that teach us unexplained elements of behaviour; an example is the Cam clay constitutive models of critical state soil mechanics (CSSM). 'Engineer's models' are models that elaborate the theory to fit more behavioural trends; this is usually done by adding fitting parameters to the student's models. Can currently unexplained behavioural trends of soil be explained without adding fitting parameters to CSSM models, by developing alternative student's models based on modern theories?Here I apply an alternative theory to CSSM, called 'breakage mechanics', and develop a simple student's model for sand. Its unique and distinctive feature is the use of an energy balance equation that connects grain size reduction to consumption of energy, which enables us to predict how grain size distribution (gsd) evolves-an unprecedented capability in constitutive modelling. With only four parameters, the model is physically clarifying what CSSM cannot for sand: the dependency of yielding and critical state on the initial gsd and void ratio.

The Effect of Friction Stir Processing on Microstructure and Tensile Behavior of Thixomolded AZ91 Magnesium Alloy

NASA Astrophysics Data System (ADS)

Mansoor, B.; Decker, R. F.; Kulkarni, S.; LeBeau, S. E.; Khraisheh, M. K.

Friction Stir Processing (FSP) to partial sheet thickness can be utilized to engineer unique microstructures in metallic alloys. These composite microstructures consist of three distinct layers associated with stirred, transition and core micro structural regions. The stirred region is of particular interest where severe plastic deformation imparted by the rotating and translating FSP tool under frictional heat leads to grain refinement down to 1 urn grain size. In this work, partial depth penetration into thixomolded AZ91 Mg plate from the top and bottom surfaces by friction stir processing is explored. Furthermore, low temperature aging treatments are applied to the processed material. The present results with AZ91 Mg show that FSP processed material exhibits higher strength (> 300 MPa), and improvement in ductility (> 7 % tensile elongation). It is found that in addition to Hall-Petch strengthening produced by 1 um grain size in the stirred region, the enhanced strength levels and ductility are strongly influenced by dispersoids of the intermetallic precipitates found in this alloy.

Engineering and Scaling the Spontaneous Magnetization Reversal of Faraday Induced Magnetic Relaxation in Nano-Sized Amorphous Ni Coated on Crystalline Au.

PubMed

Li, Wen-Hsien; Lee, Chi-Hung; Kuo, Chen-Chen

2016-05-28

We report on the generation of large inverse remanent magnetizations in nano-sized core/shell structure of Au/Ni by turning off the applied magnetic field. The remanent magnetization is very sensitive to the field reduction rate as well as to the thermal and field processes before the switching off of the magnetic field. Spontaneous reversal in direction and increase in magnitude of the remanent magnetization in subsequent relaxations over time were found. All of the various types of temporal relaxation curves of the remanent magnetizations are successfully scaled by a stretched exponential decay profile, characterized by two pairs of relaxation times and dynamic exponents. The relaxation time is used to describe the reduction rate, while the dynamic exponent describes the dynamical slowing down of the relaxation through time evolution. The key to these effects is to have the induced eddy current running beneath the amorphous Ni shells through Faraday induction.

Biocatalysis engineering: the big picture.

PubMed

Sheldon, Roger A; Pereira, Pedro C

2017-05-22

In this tutorial review we describe a holistic approach to the invention, development and optimisation of biotransformations utilising isolated enzymes. Increasing attention to applied biocatalysis is motivated by its numerous economic and environmental benefits. Biocatalysis engineering concerns the development of enzymatic systems as a whole, which entails engineering its different components: substrate engineering, medium engineering, protein (enzyme) engineering, biocatalyst (formulation) engineering, biocatalytic cascade engineering and reactor engineering.

A Process for Capturing the Art of Systems Engineering

NASA Technical Reports Server (NTRS)

Owens, Clark V., III; Sekeres, Carrie; Roumie, Yasmeen

2016-01-01

There is both an art and a science to systems engineering. The science of systems engineering is effectively captured in processes and procedures, but the art is much more elusive. We propose that there is six step process that can be applied to any systems engineering organization to create an environment from which the "art" of that organization can be captured, be allowed to evolve collaboratively and be shared with all members of the organization. This paper details this process as it was applied to NASA Launch Services Program (LSP) Integration Engineering Branch during a pilot program of Confluence, a Commercial Off The Shelf (COTS) wiki tool.

Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

1993-01-01

In order to reduce heat transfer between a hot gas heat source and a metallic engine component, a thermal insulating layer of material is placed between them. This thermal barrier coating is applied by plasma spray processing the thin films. The coating has been successfully employed in aerospace applications for many years. Lewis Research Center, a leader in the development engine components coating technology, has assisted Caterpillar, Inc. in applying ceramic thermal barrier coatings on engines. Because these large engines use heavy fuels containing vanadium, engine valve life is sharply decreased. The barrier coating controls temperatures, extends valve life and reduces operating cost. Additional applications are currently under development.

A Technique of Two-Stage Clustering Applied to Environmental and Civil Engineering and Related Methods of Citation Analysis.

ERIC Educational Resources Information Center

Miyamoto, S.; Nakayama, K.

1983-01-01

A method of two-stage clustering of literature based on citation frequency is applied to 5,065 articles from 57 journals in environmental and civil engineering. Results of related methods of citation analysis (hierarchical graph, clustering of journals, multidimensional scaling) applied to same set of articles are compared. Ten references are…

40 CFR 1039.101 - What exhaust emission standards must my engines meet after the 2014 model year?

Code of Federal Regulations, 2013 CFR

2013-07-01

... emission standards must my engines meet after the 2014 model year? The exhaust emission standards of this section apply after the 2014 model year. Certain of these standards also apply for model year 2014 and... emission standards that apply to 2014 and earlier model years. Section 1039.105 specifies smoke standards...

40 CFR 1039.101 - What exhaust emission standards must my engines meet after the 2014 model year?

Code of Federal Regulations, 2014 CFR

2014-07-01

... emission standards must my engines meet after the 2014 model year? The exhaust emission standards of this section apply after the 2014 model year. Certain of these standards also apply for model year 2014 and... emission standards that apply to 2014 and earlier model years. Section 1039.105 specifies smoke standards...

40 CFR 1039.101 - What exhaust emission standards must my engines meet after the 2014 model year?

Code of Federal Regulations, 2012 CFR

2012-07-01

... emission standards must my engines meet after the 2014 model year? The exhaust emission standards of this section apply after the 2014 model year. Certain of these standards also apply for model year 2014 and... emission standards that apply to 2014 and earlier model years. Section 1039.105 specifies smoke standards...

40 CFR 1039.101 - What exhaust emission standards must my engines meet after the 2014 model year?

Code of Federal Regulations, 2011 CFR

2011-07-01

... emission standards must my engines meet after the 2014 model year? The exhaust emission standards of this section apply after the 2014 model year. Certain of these standards also apply for model year 2014 and... emission standards that apply to 2014 and earlier model years. Section 1039.105 specifies smoke standards...

Advanced rotary engine studies

NASA Technical Reports Server (NTRS)

Jones, C.

1980-01-01

A review of rotary engine developments relevant to a stratified charge rotary aircraft engine is presented. Advantages in module size and weight, fuel efficiency, reliability, and multi-fuel capability are discussed along with developments in turbocharging, increased mean effective pressure, improved apex seal/trochoid wear surfacing materials, and high strength and temperature aluminum casting alloys. A carbureted prototype aircraft engine is also described.

A Short Course in Problems in Applied Science and Engineering.

ERIC Educational Resources Information Center

Nicholson, H. W.

1987-01-01

Provides a description of a concentrated four-week term course that provided students with opportunities of association with applied science and engineering professionals. Reviews the program's organizational structure, project requirements, and summarizes students reactions to the course. (ML)

Research Capabilities for Oil-Free Turbomachinery Expanded by New Rotordynamic Simulator Facility

NASA Technical Reports Server (NTRS)

Howard, Samuel A.

2004-01-01

A new test rig has been developed for simulating high-speed turbomachinery shafting using Oil-Free foil air bearing technology. Foil air journal bearings are self-acting hydrodynamic bearings with a flexible inner sleeve surface using air as the lubricant. These bearings have been used in turbomachinery, primarily air cycle machines, for the past four decades to eliminate the need for oil lubrication. More recently, interest has been growing in applying foil bearings to aircraft gas turbine engines. They offer potential improvements in efficiency and power density, decreased maintenance costs, and other secondary benefits. The goal of applying foil air bearings to aircraft gas turbine engines prompted the fabrication of this test rig. The facility enables bearing designers to test potential bearing designs with shafts that simulate the rotating components of a target engine without the high cost of building actual flight hardware. The data collected from this rig can be used to make changes to the shaft and bearings in subsequent design iterations. The rest of this article describes the new test rig and demonstrates some of its capabilities with an initial simulated shaft system. The test rig has two support structures, each housing a foil air journal bearing. The structures are designed to accept any size foil journal bearing smaller than 63 mm (2.5 in.) in diameter. The bearing support structures are mounted to a 91- by 152-cm (3- by 5-ft) table and can be separated by as much as 122 cm (4 ft) and as little as 20 cm (8 in.) to accommodate a wide range of shaft sizes. In the initial configuration, a 9.5-cm (3.75-in.) impulse air turbine drives the test shaft. The impulse turbine, as well as virtually any number of "dummy" compressor and turbine disks, can be mounted on the shaft inboard or outboard of the bearings. This flexibility allows researchers to simulate various engine shaft configurations. The bearing support structures include a unique bearing mounting fixture that rotates to accommodate a laserbased alignment system. This can measure the misalignment of the bearing centers in each of 2 translational degrees of freedom and 2 rotational degrees of freedom. In the initial configuration, with roughly a 30.5-cm- (12-in.-) long shaft, two simulated aerocomponent disks, and two 50.8-cm (2-in.) foil journal bearings, the rig can operate at 65,000 rpm at room temperature. The test facility can measure shaft displacements in both the vertical and horizontal directions at each bearing location. Horizontal and vertical structural vibrations are monitored using accelerometers mounted on the bearing support structures. This information is used to determine system rotordynamic response, including critical speeds, mode shapes, orbit size and shape, and potentially the onset of instabilities. Bearing torque can be monitored as well to predict the power loss in the foil bearings. All of this information is fed back and forth between NASA and the foil bearing designers in an iterative fashion to converge on a final bearing and shaft design for a given engine application. In addition to its application development capabilities, the test rig offers several unique capabilities for basic bearing research. Using the laser alignment system mentioned earlier, the facility will be used to map foil air journal bearing performance. A known misalignment of increasing severity will be induced to determine the sensitivity of foil bearings to misalignment. Other future plans include oil-free integral starter generator testing and development, and dynamic load testing of foil journal bearings.

Reduction of diesel engine exhaust noise in the petroleum mining industry. [by resonator type diffuser

NASA Technical Reports Server (NTRS)

Marinov, T.

1974-01-01

An important noise source in a drilling plant is Diesel engine exhaust. In order to reduce this noise, a reactive silencer of the derivative resonator type was proposed, calculated from the acoustic and design point of view and applied. As a result of applying such a silencer on the exhaust conduit of a Diesel engine the noise level dropped down to 18 db.

Engine Data Interpretation System (EDIS), phase 2

NASA Technical Reports Server (NTRS)

Cost, Thomas L.; Hofmann, Martin O.

1991-01-01

A prototype of an expert system was developed which applies qualitative constraint-based reasoning to the task of post-test analysis of data resulting from a rocket engine firing. Data anomalies are detected and corresponding faults are diagnosed. Engine behavior is reconstructed using measured data and knowledge about engine behavior. Knowledge about common faults guides but does not restrict the search for the best explanation in terms of hypothesized faults. The system contains domain knowledge about the behavior of common rocket engine components and was configured for use with the Space Shuttle Main Engine (SSME). A graphical user interface allows an expert user to intimately interact with the system during diagnosis. The system was applied to data taken during actual SSME tests where data anomalies were observed.

7 CFR 1724.31 - Engineering services contracts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Engineering services contracts. 1724.31 Section 1724..., DEPARTMENT OF AGRICULTURE ELECTRIC ENGINEERING, ARCHITECTURAL SERVICES AND DESIGN POLICIES AND PROCEDURES Engineering Services § 1724.31 Engineering services contracts. The provisions of this section apply only to...

7 CFR 1724.31 - Engineering services contracts.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 11 2014-01-01 2014-01-01 false Engineering services contracts. 1724.31 Section 1724..., DEPARTMENT OF AGRICULTURE ELECTRIC ENGINEERING, ARCHITECTURAL SERVICES AND DESIGN POLICIES AND PROCEDURES Engineering Services § 1724.31 Engineering services contracts. The provisions of this section apply only to...

7 CFR 1724.31 - Engineering services contracts.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 11 2011-01-01 2011-01-01 false Engineering services contracts. 1724.31 Section 1724..., DEPARTMENT OF AGRICULTURE ELECTRIC ENGINEERING, ARCHITECTURAL SERVICES AND DESIGN POLICIES AND PROCEDURES Engineering Services § 1724.31 Engineering services contracts. The provisions of this section apply only to...

7 CFR 1724.31 - Engineering services contracts.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 11 2013-01-01 2013-01-01 false Engineering services contracts. 1724.31 Section 1724..., DEPARTMENT OF AGRICULTURE ELECTRIC ENGINEERING, ARCHITECTURAL SERVICES AND DESIGN POLICIES AND PROCEDURES Engineering Services § 1724.31 Engineering services contracts. The provisions of this section apply only to...

7 CFR 1724.31 - Engineering services contracts.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 11 2012-01-01 2012-01-01 false Engineering services contracts. 1724.31 Section 1724..., DEPARTMENT OF AGRICULTURE ELECTRIC ENGINEERING, ARCHITECTURAL SERVICES AND DESIGN POLICIES AND PROCEDURES Engineering Services § 1724.31 Engineering services contracts. The provisions of this section apply only to...

40 CFR 1065.518 - Engine preconditioning.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Engine preconditioning. 1065.518... CONTROLS ENGINE-TESTING PROCEDURES Performing an Emission Test Over Specified Duty Cycles § 1065.518 Engine preconditioning. (a) This section applies for engines where measured emissions are affected by prior operation...

Impact of workstations on criticality analyses at ABB combustion engineering

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

Tarko, L.B.; Freeman, R.S.; O'Donnell, P.F.

1993-01-01

During 1991, ABB Combustion Engineering (ABB C-E) made the transition from a CDC Cyber 990 mainframe for nuclear criticality safety analyses to Hewlett Packard (HP)/Apollo workstations. The primary motivation for this change was improved economics of the workstation and maintaining state-of-the-art technology. The Cyber 990 utilized the NOS operating system with a 60-bit word size. The CPU memory size was limited to 131 100 words of directly addressable memory with an extended 250000 words available. The Apollo workstation environment at ABB consists of HP/Apollo-9000/400 series desktop units used by most application engineers, networked with HP/Apollo DN10000 platforms that use 32-bitmore » word size and function as the computer servers and network administrative CPUS, providing a virtual memory system.« less

Space Shuttle Project

NASA Image and Video Library

1977-08-01

A workman reams holes to the proper size and aligment in the Space Shuttle Main Engine's main injector body, through which propellants will pass through on their way into the engine's combustion chamber. Rockwell International's Rocketdyne Division plant produced the engines under contract to the Marshall Space Flight Center.

High Bypass Turbofan Component Development. Phase II. Detailed Design.

DTIC Science & Technology

1979-08-01

Selecting Blade Thickness for Bird Strike 46 27. Method for Selecting Blade Airfoil Attachment 49 AIRCRAF ENGINE GROUP IV GENERAL ELECTRIC COMPANY...reserves, the replacement aircraft must have a fuel efficient engine as the propulsion system, i. e., * modern turbofan engine . Technology in the large... turbofan engines has been well demonstrated, but little has been done in the size applicable to a twin- engine primary trainer aircraft . Today, there is

48 CFR 926.7004 - Size standard for Energy Policy Act procurements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Policy Act of 1992 926.7004 Size standard for Energy Policy Act procurements. The size standard for Energy Policy Act engineering services procurements (SIC 8711) shall be the size standard specified for... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Size standard for Energy...

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.

Pit bearing capacity effect on status of soil plug during pile driving in ocean engineering

NASA Astrophysics Data System (ADS)

Yan, Shu-Wang; Zhou, Qun-Hua; Liu, Run; Dong, Wei

2011-06-01

Foundation piles of the offshore oil platforms in the Bohai Bay are usually longer than 100 m with a diameter larger than 2 m. Driving such long and large-sized piles into the ground is a difficult task. It needs a comprehensive consider ation of the pile dimensions, soil properties and the hammer energy. Thoughtful drivability analysis has to be performed in the design stage. It has been shown that judging whether the soil column inside the pile is fully plugged, which makes the pile behave as close-ended, strongly influences the accuracy of drivability analysis. Engineering practice repeatedly indicates that the current methods widely used for soil plug judgment often give incorrect results, leading the designers to make a wrong decision. It has been found that this problem is caused by the ignorance of the bearing capacity provided by the soil surrounding the pile. Based on the Terzaghi's bearing capacity calculation method for deep foundation, a new approach for judging soil plug status is put forward, in which the surcharge effect has been considered and the dynamic effect coefficient is included. This approach has been applied to some practical engineering projects successfully, which may give more reasonable results than the currently used method does.

An Investigation of the Coefficient of Discharge of Liquids Through Small Round Orifices

NASA Technical Reports Server (NTRS)

Joachim, W F

1926-01-01

The work covered by this report was undertaken in connection with a general investigation of fuel injection engine principles as applied to engines for aircraft propulsion, the specific purpose being to obtain information on the coefficient of discharge of small round orifices suitable for use as fuel injection nozzles. Values for the coefficient were determined for the more important conditions of engine service such as discharge under pressures up to 8,000 pounds per square inch, at temperatures between 80 degrees and 180 degrees F. And into air compressed to pressures up to 1,000 pounds per square inch. The results show that the coefficient ranges between 0.62 and 0.88 for the different test conditions between 1,000 and 8,000 pounds per square inch hydraulic pressure. At lower pressures the coefficient increases materially. It is concluded that within the range of these tests and for hydraulic pressures above 1,000 pound per square inch the coefficient does not change materially with pressure or temperature; that it depends considerably upon the liquid, decreases with increase in orifice size, and increases in the case of discharge into compressed air until the compressed-air pressure equals approximately three-tenths of the hydraulic pressure, beyond which pressure ratio it remains practically constant.

Software engineering processes for Class D missions

NASA Astrophysics Data System (ADS)

Killough, Ronnie; Rose, Debi

2013-09-01

Software engineering processes are often seen as anathemas; thoughts of CMMI key process areas and NPR 7150.2A compliance matrices can motivate a software developer to consider other career fields. However, with adequate definition, common-sense application, and an appropriate level of built-in flexibility, software engineering processes provide a critical framework in which to conduct a successful software development project. One problem is that current models seem to be built around an underlying assumption of "bigness," and assume that all elements of the process are applicable to all software projects regardless of size and tolerance for risk. This is best illustrated in NASA's NPR 7150.2A in which, aside from some special provisions for manned missions, the software processes are to be applied based solely on the criticality of the software to the mission, completely agnostic of the mission class itself. That is, the processes applicable to a Class A mission (high priority, very low risk tolerance, very high national significance) are precisely the same as those applicable to a Class D mission (low priority, high risk tolerance, low national significance). This paper will propose changes to NPR 7150.2A, taking mission class into consideration, and discuss how some of these changes are being piloted for a current Class D mission—the Cyclone Global Navigation Satellite System (CYGNSS).

Pigs taking wing with transposons and recombinases

PubMed Central

Clark, Karl J; Carlson, Daniel F; Fahrenkrug, Scott C

2007-01-01

Swine production has been an important part of our lives since the late Mesolithic or early Neolithic periods, and ranks number one in world meat production. Pig production also contributes to high-value-added medical markets in the form of pharmaceuticals, heart valves, and surgical materials. Genetic engineering, including the addition of exogenous genetic material or manipulation of the endogenous genome, holds great promise for changing pig phenotypes for agricultural and medical applications. Although the first transgenic pigs were described in 1985, poor survival of manipulated embryos; inefficiencies in the integration, transmission, and expression of transgenes; and expensive husbandry costs have impeded the widespread application of pig genetic engineering. Sequencing of the pig genome and advances in reproductive technologies have rejuvenated efforts to apply transgenesis to swine. Pigs provide a compelling new resource for the directed production of pharmaceutical proteins and the provision of cells, vascular grafts, and organs for xenotransplantation. Additionally, given remarkable similarities in the physiology and size of people and pigs, swine will increasingly provide large animal models of human disease where rodent models are insufficient. We review the challenges facing pig transgenesis and discuss the utility of transposases and recombinases for enhancing the success and sophistication of pig genetic engineering. 'The paradise of my fancy is one where pigs have wings.' (GK Chesterton). PMID:18047690

Inter-printer color calibration using constrained printer gamut

NASA Astrophysics Data System (ADS)

Zeng, Huanzhao; Humet, Jacint

2005-01-01

Due to the drop size variation of the print heads in inkjet printers, consistent color reproduction becomes challenge for high quality color printing. To improve the color consistency, we developed a method and system to characterize a pair of printers using a colorimeter or a color scanner. Different from prior known approaches that simply try to match colors of one printer to the other without considering the gamut differences, we first constructed an overlapped gamut in which colors can be produced by both printers, and then characterized both printers using a pair of 3-D or 4-D lookup tables (LUT) to produce same colors limited to the overlapped gamut. Each LUT converts nominal device color values into engine-dependent device color values limited to the overlapped gamut. Compared to traditional approaches, the color calibration accuracy is significantly improved. This method can be simply extended to calibrate more than two engines. In a color imaging system that includes a scanner and more than one print engine, this method improves the color consistency very effectively without increasing hardware costs. A few examples for applying this method are: 1) one-pass bi-directional inkjet printing; 2) a printer with two or more sets of pens for printing; and 3) a system embedded with a pair of printers (the number of printers could be easily incremented).

Grain boundary engineering: fatigue fracture

NASA Astrophysics Data System (ADS)

Das, Arpan

2017-04-01

Grain boundary engineering has revealed significant enhancement of material properties by modifying the populations and connectivity of different types of grain boundaries within the polycrystals. The character and connectivity of grain boundaries in polycrystalline microstructures control the corrosion and mechanical behaviour of materials. A comprehensive review of the previous researches has been carried out to understand this philosophy. Present research thoroughly explores the effect of total strain amplitude on phase transformation, fatigue fracture features, grain size, annealing twinning, different grain connectivity and grain boundary network after strain controlled low cycle fatigue deformation of austenitic stainless steel under ambient temperature. Electron backscatter diffraction technique has been used extensively to investigate the grain boundary characteristics and morphologies. The nominal variation of strain amplitude through cyclic plastic deformation is quantitatively demonstrated completely in connection with the grain boundary microstructure and fractographic features to reveal the mechanism of fatigue fracture of polycrystalline austenite. The extent of boundary modifications has been found to be a function of the number of applied loading cycles and strain amplitudes. It is also investigated that cyclic plasticity induced martensitic transformation strongly influences grain boundary characteristics and modifications of the material's microstructure/microtexture as a function of strain amplitudes. The experimental results presented here suggest a path to grain boundary engineering during fatigue fracture of austenite polycrystals.

Quantification of uncertainty in photon source spot size inference during laser-driven radiography experiments at TRIDENT

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

Tobias, Benjamin John; Palaniyappan, Sasikumar; Gautier, Donald Cort

Images of the R2DTO resolution target were obtained during laser-driven-radiography experiments performed at the TRIDENT laser facility, and analysis of these images using the Bayesian Inference Engine (BIE) determines a most probable full-width half maximum (FWHM) spot size of 78 μm. However, significant uncertainty prevails due to variation in the measured detector blur. Propagating this uncertainty in detector blur through the forward model results in an interval of probabilistic ambiguity spanning approximately 35-195 μm when the laser energy impinges on a thick (1 mm) tantalum target. In other phases of the experiment, laser energy is deposited on a thin (~100more » nm) aluminum target placed 250 μm ahead of the tantalum converter. When the energetic electron beam is generated in this manner, upstream from the bremsstrahlung converter, the inferred spot size shifts to a range of much larger values, approximately 270-600 μm FWHM. This report discusses methods applied to obtain these intervals as well as concepts necessary for interpreting the result within a context of probabilistic quantitative inference.« less

Multi-Functional Carbon Fibre Composites using Carbon Nanotubes as an Alternative to Polymer Sizing

PubMed Central

Pozegic, T. R.; Anguita, J. V.; Hamerton, I.; Jayawardena, K. D. G. I.; Chen, J-S.; Stolojan, V.; Ballocchi, P.; Walsh, R.; Silva, S. R. P.

2016-01-01

Carbon fibre reinforced polymers (CFRP) were introduced to the aerospace, automobile and civil engineering industries for their high strength and low weight. A key feature of CFRP is the polymer sizing - a coating applied to the surface of the carbon fibres to assist handling, improve the interfacial adhesion between fibre and polymer matrix and allow this matrix to wet-out the carbon fibres. In this paper, we introduce an alternative material to the polymer sizing, namely carbon nanotubes (CNTs) on the carbon fibres, which in addition imparts electrical and thermal functionality. High quality CNTs are grown at a high density as a result of a 35 nm aluminium interlayer which has previously been shown to minimise diffusion of the catalyst in the carbon fibre substrate. A CNT modified-CFRP show 300%, 450% and 230% improvements in the electrical conductivity on the ‘surface’, ‘through-thickness’ and ‘volume’ directions, respectively. Furthermore, through-thickness thermal conductivity calculations reveal a 107% increase. These improvements suggest the potential of a direct replacement for lightning strike solutions and to enhance the efficiency of current de-icing solutions employed in the aerospace industry. PMID:27876858

Multi-Functional Carbon Fibre Composites using Carbon Nanotubes as an Alternative to Polymer Sizing

NASA Astrophysics Data System (ADS)

Pozegic, T. R.; Anguita, J. V.; Hamerton, I.; Jayawardena, K. D. G. I.; Chen, J.-S.; Stolojan, V.; Ballocchi, P.; Walsh, R.; Silva, S. R. P.

2016-11-01

Carbon fibre reinforced polymers (CFRP) were introduced to the aerospace, automobile and civil engineering industries for their high strength and low weight. A key feature of CFRP is the polymer sizing - a coating applied to the surface of the carbon fibres to assist handling, improve the interfacial adhesion between fibre and polymer matrix and allow this matrix to wet-out the carbon fibres. In this paper, we introduce an alternative material to the polymer sizing, namely carbon nanotubes (CNTs) on the carbon fibres, which in addition imparts electrical and thermal functionality. High quality CNTs are grown at a high density as a result of a 35 nm aluminium interlayer which has previously been shown to minimise diffusion of the catalyst in the carbon fibre substrate. A CNT modified-CFRP show 300%, 450% and 230% improvements in the electrical conductivity on the ‘surface’, ‘through-thickness’ and ‘volume’ directions, respectively. Furthermore, through-thickness thermal conductivity calculations reveal a 107% increase. These improvements suggest the potential of a direct replacement for lightning strike solutions and to enhance the efficiency of current de-icing solutions employed in the aerospace industry.

Multi-Functional Carbon Fibre Composites using Carbon Nanotubes as an Alternative to Polymer Sizing.

PubMed

Pozegic, T R; Anguita, J V; Hamerton, I; Jayawardena, K D G I; Chen, J-S; Stolojan, V; Ballocchi, P; Walsh, R; Silva, S R P

2016-11-23

Carbon fibre reinforced polymers (CFRP) were introduced to the aerospace, automobile and civil engineering industries for their high strength and low weight. A key feature of CFRP is the polymer sizing - a coating applied to the surface of the carbon fibres to assist handling, improve the interfacial adhesion between fibre and polymer matrix and allow this matrix to wet-out the carbon fibres. In this paper, we introduce an alternative material to the polymer sizing, namely carbon nanotubes (CNTs) on the carbon fibres, which in addition imparts electrical and thermal functionality. High quality CNTs are grown at a high density as a result of a 35 nm aluminium interlayer which has previously been shown to minimise diffusion of the catalyst in the carbon fibre substrate. A CNT modified-CFRP show 300%, 450% and 230% improvements in the electrical conductivity on the 'surface', 'through-thickness' and 'volume' directions, respectively. Furthermore, through-thickness thermal conductivity calculations reveal a 107% increase. These improvements suggest the potential of a direct replacement for lightning strike solutions and to enhance the efficiency of current de-icing solutions employed in the aerospace industry.

Effect of drop size on the impact thermodynamics for supercooled large droplet in aircraft icing

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

Zhang, Chen; Liu, Hong, E-mail: hongliu@sjtu.edu.cn

Supercooled large droplet (SLD), which can cause abnormal icing, is a well-known issue in aerospace engineering. Although efforts have been exerted to understand large droplet impact dynamics and the supercooled feature in the film/substrate interface, respectively, the thermodynamic effect during the SLD impact process has not received sufficient attention. This work conducts experimental studies to determine the effects of drop size on the thermodynamics for supercooled large droplet impingement. Through phenomenological reproduction, the rapid-freezing characteristics are observed in diameters of 400, 800, and 1300 μm. The experimental analysis provides information on the maximum spreading rate and the shrinkage rate ofmore » the drop, the supercooled diffusive rate, and the freezing time. A physical explanation of this unsteady heat transfer process is proposed theoretically, which indicates that the drop size is a critical factor influencing the supercooled heat exchange and effective heat transfer duration between the film/substrate interface. On the basis of the present experimental data and theoretical analysis, an impinging heating model is developed and applied to typical SLD cases. The model behaves as anticipated, which underlines the wide applicability to SLD icing problems in related fields.« less

TOPICAL REVIEW: Progress in engineering high strain lead-free piezoelectric ceramics

NASA Astrophysics Data System (ADS)

Leontsev, Serhiy O.; Eitel, Richard E.

2010-08-01

Environmental concerns are strongly driving the need to replace the lead-based piezoelectric materials currently employed as multilayer actuators. The current review describes both compositional and structural engineering approaches to achieve enhanced piezoelectric properties in lead-free materials. The review of the compositional engineering approach focuses on compositional tuning of the properties and phase behavior in three promising families of lead-free perovskite ferroelectrics: the titanate, alkaline niobate and bismuth perovskites and their solid solutions. The 'structural engineering' approaches focus instead on optimization of microstructural features including grain size, grain orientation or texture, ferroelectric domain size and electrical bias field as potential paths to induce large piezoelectric properties in lead-free piezoceramics. It is suggested that a combination of both compositional and novel structural engineering approaches will be required in order to realize viable lead-free alternatives to current lead-based materials for piezoelectric actuator applications.

Characteristics and engineering properties of residual soil of volcanic deposits

NASA Astrophysics Data System (ADS)

Wibawa, Y. S.; Sugiarti, K.; Soebowo, E.

2018-02-01

Residual soil knowledge of volcanic-sedimentary rock products provides important information on the soil bearing capacity and its engineering properties. The residual soil is the result of weathering commonly found in unsaturated conditions, having varied geotechnical characteristics at each level of weathering. This paper summarizes the results of the research from the basic engineering properties of residual soil of volcanic-sedimentary rocks from several different locations. The main engineering properties of residual soil such as specific gravity, porosity, grain size, clay content (X-Ray test) and soil shear strength are performed on volcanic rock deposits. The results show that the variation of the index and engineering properties and the microstructure properties of residual soil have the correlation between the depths of weathering levels. Pore volume and pore size distribution on weathered rock profiles can be used as an indication of weathering levels in the tropics.

Final Rule for Gasoline Spark-Ignition Marine Engines; Exemptions for New Nonroad Compression-Ignition Engines at or Above 37 Kilowatts and New Nonroad Spark-Ignition Engines at or Below 19 Kilowatts

EPA Pesticide Factsheets

These standards apply for outboard engines, personal watercraft engines, and jet boat engines. This rule also adds a national security exemption for Nonroad Compression-Ignition (CI) and Small SI sectors.

BENCHMARKING SUSTAINABILITY ENGINEERING EDUCATION

EPA Science Inventory

The goals of this project are to develop and apply a methodology for benchmarking curricula in sustainability engineering and to identify individuals active in sustainability engineering education.

Production and Assessment of Damaged High Energy Propellant Samples,

DTIC Science & Technology

1980-05-08

and (c) -69.8% ...... 14 3 Longitudinal Velocity one hour after Compressing Versus Applied Engineering Compressive Strain for Propellant Samples...LONGITUDINAL VELOCITY ONE HOUR AFTER COMPRESSING VERSUS APPLIED ENGINEERING COMPRESSIVE STRAIN FOR PROPELLANT SAMPLES (NOMINAL 40 mm DIA x 13 mm HIGH

Research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis and computer science

NASA Technical Reports Server (NTRS)

1987-01-01

Research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, numerical analysis, and computer science during the period April, 1986 through September 30, 1986 is summarized.

A study of the Armstrong Whitworth swing beam engine for automotive application

NASA Technical Reports Server (NTRS)

1983-01-01

The introduction of ceramics to those parts suffering high thermal loading was successfully demonstrated, and there is no question that the 100 kw (134 hp) naturally aspirated engine of the future will be developed to produce up to 300 kw (402 hp) by the application of turbocharging or its equivalent. However, at the 60 - 80 kw (80 - 107 hp) size needed for the economic automotive engine, scaling down the 300 kw (402 hp) is beset by the laws of scale. The conventional four stroke diesel was not shown to be successful at the small high speed engine size. The opposed piston two stroke engine does not suffer the same laws of scale and engines in the low power range have already been marketed successfully. The half liter/cylinder Armstrong Whitworth Swing Beam Engine is the latest to be designed with the automotive market in mind. Its low noise structure and balanced linkage system coupled with advantages for easy start and potential use of low grade fuels, derived from its variable compression ratio and slow piston motion, qualifies it for the application.

The second law of thermodynamics and quantum heat engines: Is the law strictly enforced?

NASA Astrophysics Data System (ADS)

Keefe, Peter D.

2010-01-01

A quantum heat engine is a construct having a working medium which is cyclically processed through a pair of control variables of state involving a Bose-Einstein condensation (BEC) in which a heat input is converted into a work output. Of interest is a first species of quantum heat engine in which the working medium is macroscopic in the sense the size scale is sufficiently large that the BEC is not volumetrically coherent. In this first species of quantum heat engine, near Carnot efficiencies may be possible. Of particular interest is a second species of quantum heat engine in which the working medium is mesoscopic in the sense that the size scale is sufficiently small that the BEC is volumetrically coherent. In this second species of quantum heat engine, the resulting in-process non-equilibrium condition affects the finally arrived at control variables of state such that Carnot efficiencies and beyond may be possible. A Type I superconductor is used to model the first and second species of quantum heat engine.

Engineering of an inhalable DDA/TDB liposomal adjuvant: a quality-by-design approach towards optimization of the spray drying process.

PubMed

Ingvarsson, Pall Thor; Yang, Mingshi; Mulvad, Helle; Nielsen, Hanne Mørck; Rantanen, Jukka; Foged, Camilla

2013-11-01

The purpose of this study was to identify and optimize spray drying parameters of importance for the design of an inhalable powder formulation of a cationic liposomal adjuvant composed of dimethyldioctadecylammonium (DDA) bromide and trehalose-6,6'-dibehenate (TDB). A quality by design (QbD) approach was applied to identify and link critical process parameters (CPPs) of the spray drying process to critical quality attributes (CQAs) using risk assessment and design of experiments (DoE), followed by identification of an optimal operating space (OOS). A central composite face-centered design was carried out followed by multiple linear regression analysis. Four CQAs were identified; the mass median aerodynamic diameter (MMAD), the liposome stability (size) during processing, the moisture content and the yield. Five CPPs (drying airflow, feed flow rate, feedstock concentration, atomizing airflow and outlet temperature) were identified and tested in a systematic way. The MMAD and the yield were successfully modeled. For the liposome size stability, the ratio between the size after and before spray drying was modeled successfully. The model for the residual moisture content was poor, although, the moisture content was below 3% in the entire design space. Finally, the OOS was drafted from the constructed models for the spray drying of trehalose stabilized DDA/TDB liposomes. The QbD approach for the spray drying process should include a careful consideration of the quality target product profile. This approach implementing risk assessment and DoE was successfully applied to optimize the spray drying of an inhalable DDA/TDB liposomal adjuvant designed for pulmonary vaccination.

Detection, characterization and quantification of inorganic engineered nanomaterials: A review of techniques and methodological approaches for the analysis of complex samples.

PubMed

Laborda, Francisco; Bolea, Eduardo; Cepriá, Gemma; Gómez, María T; Jiménez, María S; Pérez-Arantegui, Josefina; Castillo, Juan R

2016-01-21

The increasing demand of analytical information related to inorganic engineered nanomaterials requires the adaptation of existing techniques and methods, or the development of new ones. The challenge for the analytical sciences has been to consider the nanoparticles as a new sort of analytes, involving both chemical (composition, mass and number concentration) and physical information (e.g. size, shape, aggregation). Moreover, information about the species derived from the nanoparticles themselves and their transformations must also be supplied. Whereas techniques commonly used for nanoparticle characterization, such as light scattering techniques, show serious limitations when applied to complex samples, other well-established techniques, like electron microscopy and atomic spectrometry, can provide useful information in most cases. Furthermore, separation techniques, including flow field flow fractionation, capillary electrophoresis and hydrodynamic chromatography, are moving to the nano domain, mostly hyphenated to inductively coupled plasma mass spectrometry as element specific detector. Emerging techniques based on the detection of single nanoparticles by using ICP-MS, but also coulometry, are in their way to gain a position. Chemical sensors selective to nanoparticles are in their early stages, but they are very promising considering their portability and simplicity. Although the field is in continuous evolution, at this moment it is moving from proofs-of-concept in simple matrices to methods dealing with matrices of higher complexity and relevant analyte concentrations. To achieve this goal, sample preparation methods are essential to manage such complex situations. Apart from size fractionation methods, matrix digestion, extraction and concentration methods capable of preserving the nature of the nanoparticles are being developed. This review presents and discusses the state-of-the-art analytical techniques and sample preparation methods suitable for dealing with complex samples. Single- and multi-method approaches applied to solve the nanometrological challenges posed by a variety of stakeholders are also presented. Copyright © 2015 Elsevier B.V. All rights reserved.

15 KW Small Turboelectric Power Generation System

DTIC Science & Technology

2006-08-18

1 hour per response, including the time for reviewing instnlctions, searching existing data sources, gathering and maintaining the data needed, and...pressure rise is consistent with data from the baseline compressor and a large body of published diffuser data . Table 1 LTS22 Compressor Preliminary... data on designs of 150 HP, 60 HP, and 5 HP engine size class, and in subsequent engine testing. The design methodology encompasses basic sizing

Detailed characterization of particulate matter emitted by lean-burn gasoline direct injection engine

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

Zelenyuk, Alla; Wilson, Jacqueline; Imre, Dan

This study presents detailed characterization of the chemical and physical properties of PM emitted by a 2.0L BMW lean-burn turbocharged GDI engine operated under a number of combustion strategies that include lean homogeneous, lean stratified, stoichiometric, and fuel rich conditions. We characterized PM number concentrations, size distributions, and the size, mass, compositions, and effective density of fractal and compact individual exhaust particles. For the fractal particles, these measurements yielded fractal dimension, average diameter of primary spherules, and number of spherules, void fraction, and dynamic shape factors as function of particle size. Overall, the PM properties were shown to vary significantlymore » with engine operation condition. Lean stratified operation yielded the most diesel-like size distribution and the largest PM number and mass concentrations, with nearly all particles being fractal agglomerates composed of elemental carbon with small amounts of ash and organics. In contrast, stoichiometric operation yielded a larger fraction of ash particles, especially at low speed and low load. Three distinct forms of ash particles were observed, with their fractions strongly dependent on engine operating conditions: sub-50 nm ash particles, abundant at low speed and low load, ash-containing fractal particles, and large compact ash particles that significantly contribute to PM mass loadings« less

Nondestructive ultrasonic characterization of armor grade silicon carbide

NASA Astrophysics Data System (ADS)

Portune, Andrew Richard

Ceramic materials have traditionally been chosen for armor applications for their superior mechanical properties and low densities. At high strain rates seen during ballistic events, the behavior of these materials relies upon the total volumetric flaw concentration more so than any single anomalous flaw. In this context flaws can be defined as any microstructural feature which detriments the performance of the material, potentially including secondary phases, pores, or unreacted sintering additives. Predicting the performance of armor grade ceramic materials depends on knowledge of the absolute and relative concentration and size distribution of bulk heterogeneities. Ultrasound was chosen as a nondestructive technique for characterizing the microstructure of dense silicon carbide ceramics. Acoustic waves interact elastically with grains and inclusions in large sample volumes, and were well suited to determine concentration and size distribution variations for solid inclusions. Methodology was developed for rapid acquisition and analysis of attenuation coefficient spectra. Measurements were conducted at individual points and over large sample areas using a novel technique entitled scanning acoustic spectroscopy. Loss spectra were split into absorption and scattering dominant frequency regimes to simplify analysis. The primary absorption mechanism in polycrystalline silicon carbide was identified as thermoelastic in nature. Correlations between microstructural conditions and parameters within the absorption equation were established through study of commercial and custom engineered SiC materials. Nonlinear least squares regression analysis was used to estimate the size distributions of boron carbide and carbon inclusions within commercial SiC materials. This technique was shown to additionally be capable of approximating grain size distributions in engineered SiC materials which did not contain solid inclusions. Comparisons to results from electron microscopy exhibited favorable agreement between predicted and observed distributions. Developed techniques were applied to large sample areas using scanning acoustic spectroscopy to map variations in the size distribution and concentration of grains and solid inclusions within the bulk microstructure. The experiments performed in this thesis form the foundation of a novel characterization technique capable of mapping variations in sample composition which could be extended to a wide range of dense polycrystalline heterogeneous materials.

Impact of nanotechnology on drug delivery.

PubMed

Farokhzad, Omid C; Langer, Robert

2009-01-27

Nanotechnology is the engineering and manufacturing of materials at the atomic and molecular scale. In its strictest definition from the National Nanotechnology Initiative, nanotechnology refers to structures roughly in the 1-100 nm size regime in at least one dimension. Despite this size restriction, nanotechnology commonly refers to structures that are up to several hundred nanometers in size and that are developed by top-down or bottom-up engineering of individual components. Herein, we focus on the application of nanotechnology to drug delivery and highlight several areas of opportunity where current and emerging nanotechnologies could enable entirely novel classes of therapeutics.

40 CFR 1039.102 - What exhaust emission standards and phase-in allowances apply for my engines in model year 2014...

Code of Federal Regulations, 2010 CFR

2010-07-01

... phase-in allowances apply for my engines in model year 2014 and earlier? 1039.102 Section 1039.102... year 2014 and earlier? The exhaust emission standards of this section apply for 2014 and earlier model... in paragraphs (a) and (b) of this section: (1) For each model year before 2014 noted in Tables 4...

40 CFR 1048.325 - What happens if an engine family fails the production-line testing requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false What happens if an engine family fails... SPARK-IGNITION ENGINES Testing Production-line Engines § 1048.325 What happens if an engine family fails... engine family if it fails under § 1048.315. The suspension may apply to all facilities producing engines...

40 CFR 1048.325 - What happens if an engine family fails the production-line testing requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false What happens if an engine family fails... SPARK-IGNITION ENGINES Testing Production-line Engines § 1048.325 What happens if an engine family fails... engine family if it fails under § 1048.315. The suspension may apply to all facilities producing engines...

Motivational Factors of Professional Engineers and Non-Professional Engineers in Applying for License as Professional Engineer: A Comparative Study

ERIC Educational Resources Information Center

Khamis, Nor Kamaliana; Harun, Zambri; Tahir, Mohd Faizal Mat; Wahid, Zaliha; Sabri, Mohd Anas Mohd

2013-01-01

All engineering faculties in Malaysia are required to have at least three academics who have engineering competency for each program. Having an engineering competency means academics has obtained the compulsory endorsements from the Boards of Engineers, Malaysia, BEM. Upon approval, academics seeking such competency could carry the suffix Ir. to…

Engineering Encounters: Building a Spaghetti Structure

ERIC Educational Resources Information Center

Llewellyn, Douglas; Pray, Sandra; DeRose, Rob; Ottman, William

2016-01-01

This column presents ideas and techniques to enhance science teaching. In this month's issue an upper elementary Science, technology, engineering, and math (STEM) challenge brings an engineer into the classroom while emphasizing cooperation, communication, and creativity. STEM activities come in various shapes and sizes. Some are quite involved…