Liquid Phase Sintering

NASA Technical Reports Server (NTRS)

2004-01-01

Industry spends billions of dollars each year on machine tools to manufacture products out of metal. This includes tools for cutting every kind of metal part from engine blocks to Shuttle main engine components. Cutting tool tips often break because of weak spots or defects in their composition. Based on a new concept called defect trapping, space offers a novel environment to study defect formation in molten metal materials as they solidify. After the return of these materials from space, researchers can evaluate the source of the defect and seek ways to eliminate them in products prepared on Earth. A widely used process for cutting tip manufacturing is liquid phase sintering. Compared to Earth-sintered samples which slump due to buoyancy induced by gravity, space samples are uniformly shaped and defects remain where they are formed. By studying metals sintered in space the US tool industry can potentially enhance its worldwide competitiveness. The Consortium for Materials Development in Space along with Wyle Labs, Teledyne Advanced Materials, and McDornell Douglas have conducted experiments in space.

Microgravity

NASA Image and Video Library

2004-04-15

Industry spends billions of dollars each year on machine tools to manufacture products out of metal. This includes tools for cutting every kind of metal part from engine blocks to Shuttle main engine components. Cutting tool tips often break because of weak spots or defects in their composition. Based on a new concept called defect trapping, space offers a novel environment to study defect formation in molten metal materials as they solidify. After the return of these materials from space, researchers can evaluate the source of the defect and seek ways to eliminate them in products prepared on Earth. A widely used process for cutting tip manufacturing is liquid phase sintering. Compared to Earth-sintered samples which slump due to buoyancy induced by gravity, space samples are uniformly shaped and defects remain where they are formed. By studying metals sintered in space the US tool industry can potentially enhance its worldwide competitiveness. The Consortium for Materials Development in Space along with Wyle Labs, Teledyne Advanced Materials, and McDornell Douglas have conducted experiments in space.

The Evolution of Utilizing Manual Throttles to Avoid Low LH2 NPSP at the SSME Inlet

NASA Technical Reports Server (NTRS)

Henfling, Rick

2011-01-01

Even before the first flight of the Space Shuttle, it was understood low liquid hydrogen (LH2) Net Positive Suction Pressure (NPSP) at the inlet to the Space Shuttle Main Engine (SSME) can have adverse effects on engine operation. A number of failures within both the External Tank (ET) and the Orbiter Main Propulsion System could result in a low LH2 NPSP condition. Operational workarounds were developed to take advantage of the onboard crew s ability to manually throttle down the SSMEs, which alleviated the low LH2 NPSP condition. A throttling down of the SSME resulted in an increase in NPSP, mainly due to the reduction in frictional flow losses while at a lower throttle setting. As engineers refined their understanding of the NPSP requirements for the SSME (through a robust testing program), the operational techniques evolved to take advantage of these additional capabilities. Currently the procedure, which for early Space Shuttle missions required a Return-to-Launch-Site abort, now would result in a nominal Main Engine Cut Off (MECO) and no loss of mission objectives.

Recent developments in turbomachinery component materials and manufacturing challenges for aero engine applications

NASA Astrophysics Data System (ADS)

Srinivas, G.; Raghunandana, K.; Satish Shenoy, B.

2018-02-01

In the recent years the development of turbomachinery materials performance enhancement plays a vital role especially in aircraft air breathing engines like turbojet engine, turboprop engine, turboshaft engine and turbofan engines. Especially the transonic flow engines required highly sophisticated materials where it can sustain the entire thrust which can create by the engine. The main objective of this paper is to give an overview of the present cost-effective and technological capabilities process for turbomachinery component materials. Especially the main focus is given to study the Electro physical, Photonic additive removal process and Electro chemical process for turbomachinery parts manufacture. The aeronautical propulsion based technologies are reviewed thoroughly where in surface reliability, geometrical precession, and material removal and highly strengthened composite material deposition rates usually difficult to cut dedicated steels, Titanium and Nickel based alloys. In this paper the past aeronautical and propulsion mechanical based manufacturing technologies, current sophisticated technologies and also future challenging material processing techniques are covered. The paper also focuses on the brief description of turbomachinery components of shaping process and coating in aeromechanical applications.

KSC-05PD-1587

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Patricia Slinger (left), a test engineer, and Monica Hagley, an avionics test engineer, look at a replacement orbiter point sensor chassis. Components are being tested to determine why one of the four liquid hydrogen tank low- level fuel cut-off sensors failed in a routine prelaunch check during the launch countdown July 13. The failure caused mission managers to scrub Discovery's first launch attempt. The sensor protects the Shuttle's main engines by triggering their shutdown in the event fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank (ET).

KSC-07pd3649

NASA Image and Video Library

2007-12-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the wiring is checked and validated before the tanking test on space shuttle Atlantis' external tank set for Dec. 18. The test wiring has been spliced into an electrical harness in the aft main engine compartment connected with the engine cut-off, or ECO, sensor system. The attached wiring leads to the interior of the mobile launcher platform where the time domain reflectometry, or TDR, test equipment is located. Photo credit: NASA/Kim Shiflett

KSC-07pd3644

NASA Image and Video Library

2007-12-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, a technician sets up wiring for the tanking test on space shuttle Atlantis' external tank set for Dec. 18. The test wiring has been spliced into an electrical harness in the aft main engine compartment connected with the engine cut-off, or ECO, sensor system. The attached wiring leads to the interior of the mobile launcher platform where the time domain reflectometry, or TDR, test equipment is located. Photo credit: NASA/Kim Shiflett

KSC-07pd3631

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, a technician explains how test equipment -- the blue monitor -- will be used to validate the circuit on test wiring from the electrical harness in space shuttle Atlantis' aft main engine compartment connected with the engine cut-off system. The test wiring leads from the tail mast on the mobile launcher platform to the interior where the Time Domain Reflectometry, or TDR, test equipment will be located to test the sensor system. Photo credit: NASA/Kim Shiflett

KSC-07pd3651

NASA Image and Video Library

2007-12-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the wiring is checked and validated before the tanking test on space shuttle Atlantis' external tank set for Dec. 18. The test wiring has been spliced into an electrical harness in the aft main engine compartment connected with the engine cut-off, or ECO, sensor system. The attached wiring leads to the interior of the mobile launcher platform where the time domain reflectometry, or TDR, test equipment is located. Photo credit: NASA/Kim Shiflett

KSC-07pd3648

NASA Image and Video Library

2007-12-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the wiring is checked and validated before the tanking test on space shuttle Atlantis' external tank set for Dec. 18. The test wiring has been spliced into an electrical harness in the aft main engine compartment connected with the engine cut-off, or ECO, sensor system. The attached wiring leads to the interior of the mobile launcher platform where the time domain reflectometry, or TDR, test equipment is located. Photo credit: NASA/Kim Shiflett

KSC-07pd3647

NASA Image and Video Library

2007-12-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the wiring is checked and validated before the tanking test on space shuttle Atlantis' external tank set for Dec. 18. The test wiring has been spliced into an electrical harness in the aft main engine compartment connected with the engine cut-off, or ECO, sensor system. The attached wiring leads to the interior of the mobile launcher platform where the time domain reflectometry, or TDR, test equipment is located. Photo credit: NASA/Kim Shiflett

KSC-07pd3632

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, technicians overlook wires and monitoring equipment that will be used to validate the circuit on the test wiring from the electrical harness in space shuttle Atlantis' aft main engine compartment connected with the engine cut-off system. The test wiring leads from the tail mast on the mobile launcher platform to the interior where the Time Domain Reflectometry, or TDR, test equipment will be located to test the sensor system. Photo credit: NASA/Kim Shiflett

KSC-07pd3650

NASA Image and Video Library

2007-12-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, the wiring is checked and validated before the tanking test on space shuttle Atlantis' external tank set for Dec. 18. The test wiring has been spliced into an electrical harness in the aft main engine compartment connected with the engine cut-off, or ECO, sensor system. The attached wiring leads to the interior of the mobile launcher platform where the time domain reflectometry, or TDR, test equipment is located. Photo credit: NASA/Kim Shiflett

KSC-07pd3645

NASA Image and Video Library

2007-12-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, a wiring board has been set up for the tanking test on space shuttle Atlantis' external tank set for Dec. 18. The test wiring has been spliced into an electrical harness in the aft main engine compartment connected with the engine cut-off, or ECO, sensor system. The attached wiring leads to the interior of the mobile launcher platform where the time domain reflectometry, or TDR, test equipment is located. Photo credit: NASA/Kim Shiflett

Auxiliary propulsion technology for advanced Earth-to-orbit vehicles

NASA Technical Reports Server (NTRS)

Schneider, Steven J.

1987-01-01

The payload which can be delivered to orbit by advanced Earth-to-Orbit vehicles is significantly increased by advanced subsystem technology. Any weight which can be saved by advanced subsystem design can be converted to payload at Main Engine Cut Off (MECO) given the same launch vehicle performance. The auxiliary propulsion subsystem and the impetus for the current hydrogen/oxygen technology program is examined. A review of the auxiliary propulsion requirements of advanced Earth-to-Orbit (ETO) vehicles and their proposed missions is given first. Then the performance benefits of hydrogen/oxygen auxiliary propulsion are illustrated using current shuttle data. The proposed auxiliary propulsion subsystem implementation includes liquid hydrogen/liquid oxygen (LH2/LO2) primary Reaction Control System (RCS) engines and gaseous hydrogen/gaseous oxygen (GH2/GO2) vernier RCS engines. A distribution system for the liquid cryogens to the engines is outlined. The possibility of providing one dual-phase engine that can operate on either liquid or gaseous propellants is being explored, as well as the simultaneous firing of redundant primary RCS thrusters to provide Orbital Maneuvering System (OMS) level impulse. Scavenging of propellants from integral main engine tankage is proposed to utilize main engine tank residuals and to combine launch vehicle and subsystem reserves.

KSC-07pd3646

NASA Image and Video Library

2007-12-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A at NASA's Kennedy Space Center, a technician checks the blue monitor that will be used to validate the circuit on test wiring during the tanking test on space shuttle Atlantis' external tank. The test wiring has been spliced into an electrical harness in the aft main engine compartment connected with the engine cut-off, or ECO, sensor system. The attached wiring leads to the interior of the mobile launcher platform where the time domain reflectometry, or TDR, test equipment is located. Photo credit: NASA/Kim Shiflett

KSC-05PD-1584

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Monica Hagley, an avionic test engineer, places a refurbished, spare orbiter point sensor chassis on the table. Faulty readings in the liquid hydrogen tank low-level fuel cut-off sensor are being investigated because one of the four sensors failed a routine prelaunch check during the launch countdown July 13, causing mission managers to scrub Discovery's first launch attempt. The sensor protects the Shuttle's main engines by triggering their shutdown in the event fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank (ET).

Identification of Technological Parameters of Ni-Alloys When Machining by Monolithic Ceramic Milling Tool

NASA Astrophysics Data System (ADS)

Czán, Andrej; Kubala, Ondrej; Danis, Igor; Czánová, Tatiana; Holubják, Jozef; Mikloš, Matej

2017-12-01

The ever-increasing production and the usage of hard-to-machine progressive materials are the main cause of continual finding of new ways and methods of machining. One of these ways is the ceramic milling tool, which combines the pros of conventional ceramic cutting materials and pros of conventional coating steel-based insert. These properties allow to improve cutting conditions and so increase the productivity with preserved quality known from conventional tools usage. In this paper, there is made the identification of properties and possibilities of this tool when machining of hard-to-machine materials such as nickel alloys using in airplanes engines. This article is focused on the analysis and evaluation ordinary technological parameters and surface quality, mainly roughness of surface and quality of machined surface and tool wearing.

13. CLOSEUP OF AFT BULKHEAD IN THE MAIN HOLD. HORIZONTAL ...

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

13. CLOSE-UP OF AFT BULKHEAD IN THE MAIN HOLD. HORIZONTAL ALUMINUM SCALE RESTING ON STEP IS FOUR FEET LONG. THE BOTTOM OF THE HOLD IS MADE OF POURED CONCRETE AND HAS A CENTER DRAIN TO COLLECT WATER FROM MELTING ICE AND OTHER FLUIDS. THE DRAIN LED TO A SUMP CLEARED BY A BILGE PUMP WHICH PUMPED OVERBOARD. THE RECTANGULAR OPENING IN THE BULKHEAD WAS CUT TO ENABLE EASIER REMOVAL OF THE ENGINE AFTER THE EVELINA M. GOULART WAS ABANDONED. - Auxiliary Fishing Schooner "Evelina M. Goulart", Essex Shipbuilding Museum, 66 Main Street, Essex, Essex County, MA

Machining process influence on the chip form and surface roughness by neuro-fuzzy technique

NASA Astrophysics Data System (ADS)

Anicic, Obrad; Jović, Srđan; Aksić, Danilo; Skulić, Aleksandar; Nedić, Bogdan

2017-04-01

The main aim of the study was to analyze the influence of six machining parameters on the chip shape formation and surface roughness as well during turning of Steel 30CrNiMo8. Three components of cutting forces were used as inputs together with cutting speed, feed rate, and depth of cut. It is crucial for the engineers to use optimal machining parameters to get the best results or to high control of the machining process. Therefore, there is need to find the machining parameters for the optimal procedure of the machining process. Adaptive neuro-fuzzy inference system (ANFIS) was used to estimate the inputs influence on the chip shape formation and surface roughness. According to the results, the cutting force in direction of the depth of cut has the highest influence on the chip form. The testing error for the cutting force in direction of the depth of cut has testing error 0.2562. This cutting force determines the depth of cut. According to the results, the depth of cut has the highest influence on the surface roughness. Also the depth of cut has the highest influence on the surface roughness. The testing error for the cutting force in direction of the depth of cut has testing error 5.2753. Generally the depth of cut and the cutting force which provides the depth of cut are the most dominant factors for chip forms and surface roughness. Any small changes in depth of cut or in cutting force which provide the depth of cut could drastically affect the chip form or surface roughness of the working material.

KSC-05PD-1577

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Members of the engineering team are meeting in the Launch Control Center to review data and possible troubleshooting plans for the liquid hydrogen tank low-level fuel cut-off sensor. At left is John Muratore, manager of Systems Engineering and Integration for the Space Shuttle Program; Ed Mango, JSC deputy manager of the orbiter project office; and Carol Scott, KSC Integration Manager. The sensor failed a routine prelaunch check during the launch countdown July 13, causing mission managers to scrub Discovery's first launch attempt. The sensor protects the Shuttle's main engines by triggering their shutdown in the event fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank (ET).

3000-HP Roller Gear Transmission Development Program. Volume 3. Roller Gear Manufacture

DTIC Science & Technology

1975-07-01

power is fed through the ramp roller clutch type free- wheel units to spur gears which mesh with the combining spur gear whose centerline is common...when the engine tends to turn faster than the main rotor shaft. It is in the free- wheel mode when the main rotor shaft tends to turn faster than the...gears are cut progrind at this time. Check face runout on each end of largo gears. Not to exceed .002" TIR 30 EBW one end 40 EBW opposite end

STS-114 Engine Cut-off Sensor Anomaly Technical Consultation Report

NASA Technical Reports Server (NTRS)

Wilson, Timmy R.; Kichak, Robert A.; Ungar, Eugene K.; Cherney, Robert; Rickman, Steve L.

2009-01-01

The NESC consultation team participated in real-time troubleshooting of the Main Propulsion System (MPS) Engine Cutoff (ECO) sensor system failures during STS-114 launch countdown. The team assisted with External Tank (ET) thermal and ECO Point Sensor Box (PSB) circuit analyses, and made real-time inputs to the Space Shuttle Program (SSP) problem resolution teams. Several long-term recommendations resulted. One recommendation was to conduct cryogenic tests of the ECO sensors to validate, or disprove, the theory that variations in circuit impedance due to cryogenic effects on swaged connections within the sensor were the root cause of STS-114 failures.

Reviews on laser cutting technology for industrial applications

NASA Astrophysics Data System (ADS)

Muangpool, T.; Pullteap, S.

2018-03-01

In this paper, an overview of the laser technology applied for the industrial has been reviewed. In general, this technology was used in several engineering applications such as industrial, medical, science, research sectors, etc. Focusing on the laser technology in the industrial section, it was, normally, employed for many purposes i.e. target marking, welding, drilling, and also cutting. Consequently, the laser cutting technology was, however, divided into three classifications YAG, CO2, and fiber laser, respectively. Each laser types have different advantages and disadvantages depending on the material type. The advantages by using laser cutting compared with the general cutting machines were exploited in terms of narrow kerf, high cutting speed, low heat-affected zone (HAZ), improve efficiency of the cutting process, high accuracy, etc. However, the main objectives from the technology used were increasing of the products and also decreasing the production cost. In the opposite way, some disadvantages of the technology were summarized by complexity to operate, high maintenance cost, and also high power consumption. In Thailand industry, there were many factories used this technology as a cutting process. Unfortunately, only few researches were published. It might explains that this technology were difficulty to develop, high investment, and also easy to import from aboard. For becoming to the Thailand 4.0 community, the Thailand industry might awareness to reduce the importing machine and boosting some policies to create novel innovative / know-how from the own country.

Performance and emission characteristics of the thermal barrier coated SI engine by adding argon inert gas to intake mixture.

PubMed

Karthikeya Sharma, T

2015-11-01

Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE). This paper investigates the effects of using argon (Ar) gas to mitigate the spark ignition engine intake air to enhance the performance and cut down the emissions mainly nitrogen oxides. The input variables of this study include the compression ratio, stroke length, and engine speed and argon concentration. Output parameters like TE, volumetric efficiency, heat release rates, brake power, exhaust gas temperature and emissions of NOx, CO2 and CO were studied in a thermal barrier coated SI engine, under variable argon concentrations. Results of this study showed that the inclusion of Argon to the input air of the thermal barrier coated SI engine has significantly improved the emission characteristics and engine's performance within the range studied.

Whitson cuts Treschev's hair in the SM during Expedition Five on the ISS

NASA Image and Video Library

2002-07-20

ISS005-E-08151 (July 2002) --- Astronaut Peggy A. Whitson, Expedition Five flight engineer, cuts cosmonaut Sergei Y. Treschev’s hair in the Zvezda Service Module on the International Space Station (ISS). Treschev, flight engineer representing Rosaviakosmos, holds a vacuum device the crew has fashioned to garner freshly cut hair, which is floating freely.

Reiter cuts Tyurins hair in the Zvezda Service module

NASA Image and Video Library

2006-11-05

ISS014-E-07174 (5 Nov. 2006) --- European Space Agency (ESA) astronaut Thomas Reiter, Expedition 14 flight engineer, cuts the hair of cosmonaut Mikhail Tyurin, flight engineer representing Russia's Federal Space Agency, in the Unity node of the International Space Station. Reiter used hair clippers fashioned with a vacuum device to prevent freshly cut hair from being scattered throughout the module.

Hair cut

NASA Image and Video Library

2012-11-10

ISS033-E-018986 (10 Nov. 2012) --- Russian cosmonaut Evgeny Tarelkin, Expedition 33 flight engineer, trims the hair of Russian cosmonaut Oleg Novitskiy, flight engineer, in the Tranquility node of the International Space Station. Tarelkin used hair clippers fashioned with a vacuum device to garner freshly cut hair. NASA astronaut Kevin Ford, flight engineer, is visible in the background.

Expedition 33 Crew Hair Cut

NASA Image and Video Library

2012-10-21

Expedition 33 Flight Engineer Evgeny Tarelkin gets his hair cut at the Cosmonaut Hotel, on Sunday, October 21, 2012, at the Baikonur Cosmodrome in Kazakhstan. Launch of the Soyuz rocket is scheduled for October 23 and will send Expedition 33/34 Flight Engineer Kevin Ford of NASA, Soyuz Commander Oleg Novitskiy and Flight Engineer Engineer Evgeny Tarelkin of ROSCOSMOS on a five-month mission aboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

Performance and emission characteristics of the thermal barrier coated SI engine by adding argon inert gas to intake mixture

PubMed Central

Karthikeya Sharma, T.

2014-01-01

Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE). This paper investigates the effects of using argon (Ar) gas to mitigate the spark ignition engine intake air to enhance the performance and cut down the emissions mainly nitrogen oxides. The input variables of this study include the compression ratio, stroke length, and engine speed and argon concentration. Output parameters like TE, volumetric efficiency, heat release rates, brake power, exhaust gas temperature and emissions of NOx, CO2 and CO were studied in a thermal barrier coated SI engine, under variable argon concentrations. Results of this study showed that the inclusion of Argon to the input air of the thermal barrier coated SI engine has significantly improved the emission characteristics and engine’s performance within the range studied. PMID:26644918

Modified atmosphere packaging for fresh-cut fruits and vegetables

USDA-ARS?s Scientific Manuscript database

The latest development in and different aspects of modified atmosphere packaging for fresh-cut fruits and vegetables are reviewed in the book. This book provides all readers, including fresh-cut academic researchers, fresh-cut R&D personnel, and fresh-cut processing engineers, with unique, essential...

Space Shuttle Discovery Launch

NASA Image and Video Library

2008-05-31

NASA Shuttle Launch Director Michael Leinbach, left, STS-124 Assistant Launch Director Ed Mango, center, and Flow Director for Space Shuttle Discovery Stephanie Stilson clap in the the Launch Control Center after the main engine cut off and successful launch of the Space Shuttle Discovery (STS-124) Saturday, May 31, 2008, at the Kennedy Space Center in Cape Canaveral, Fla. The Shuttle lifted off from launch pad 39A at 5:02 p.m. EDT. Photo Credit: (NASA/Bill Ingalls)

Hair cut

NASA Image and Video Library

2012-11-10

ISS033-E-018991 (10 Nov. 2012) --- Russian cosmonaut Oleg Novitskiy, Expedition 33 flight engineer, trims the hair of Russian cosmonaut Evgeny Tarelkin, flight engineer, in the Tranquility node of the International Space Station. Novitskiy used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Sloshing in the Liquid Hydrogen and Liquid Oxygen Propellant Tanks After Main Engine Cut Off

NASA Technical Reports Server (NTRS)

Kim, Sura; West, Jeff

2011-01-01

NASA Marshall Space Flight Center is designing and developing the Main Propulsion System (MPS) for Ares launch vehicles. Propellant sloshing in the liquid hydrogen (LH2) and liquid oxygen (LO2) propellant tanks after Main Engine Cut Off (MECO) was modeled using the Volume of Fluid (VOF) module of the computational fluid dynamics code, CFD-ACE+. The present simulation shows that there is substantial sloshing side forces acting on the LH2 tank during the deceleration of the vehicle after MECO. The LH2 tank features a side wall drain pipe. The side loads result from the residual propellant mass motion in the LH2 tank which is initiated by the stop of flow into the drain pipe at MECO. The simulations show that radial force on the LH2 tank wall is less than 50 lbf and the radial moment calculated based up through the center of gravity of the vehicle is predicted to be as high as 300 lbf-ft. The LO2 tank features a bottom dome drain system and is equipped with sloshing baffles. The remaining LO2 in the tank slowly forms a liquid column along the centerline of tank under the zero gravity environments. The radial force on the LO2 tank wall is predicted to be less than 100 lbf. The radial moment calculated based on the center of gravity of the vehicle is predicted as high as 4500 lbf-ft just before MECO and dropped down to near zero after propellant draining stopped completely.

Advanced Health Management System for the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Davidson, Matt; Stephens, John; Rodela, Chris

2006-01-01

Pratt & Whitney Rocketdyne, Inc., in cooperation with NASA-Marshall Space Flight Center (MSFC), has developed a new Advanced Health Management System (AHMS) controller for the Space Shuttle Main Engine (SSME) that will increase the probability of successfully placing the shuttle into the intended orbit and increase the safety of the Space Transportation System (STS) launches. The AHMS is an upgrade o the current Block II engine controller whose primary component is an improved vibration monitoring system called the Real-Time Vibration Monitoring System (RTVMS) that can effectively and reliably monitor the state of the high pressure turbomachinery and provide engine protection through a new synchronous vibration redline which enables engine shutdown if the vibration exceeds predetermined thresholds. The introduction of this system required improvements and modification to the Block II controller such as redesigning the Digital Computer Unit (DCU) memory and the Flight Accelerometer Safety Cut-Off System (FASCOS) circuitry, eliminating the existing memory retention batteries, installation of the Digital Signal Processor (DSP) technology, and installation of a High Speed Serial Interface (HSSI) with accompanying outside world connectors. Test stand hot-fire testing along with lab testing have verified successful implementation and is expected to reduce the probability of catastrophic engine failures during the shuttle ascent phase and improve safely by about 23% according to the Quantitative Risk Assessment System (QRAS), leading to a safer and more reliable SSME.

Expedition 33 Crew Hair Cut

NASA Image and Video Library

2012-10-21

Expedition 33 Flight Engineer Kevin Ford gets his hair cut at the Cosmonaut Hotel, on Sunday, October 21, 2012, at the Baikonur Cosmodrome in Kazakhstan. Launch of the Soyuz rocket is scheduled for October 23 and will send Expedition 33/34 Flight Engineer Kevin Ford of NASA, Soyuz Commander Oleg Novitskiy and Flight Engineer Evgeny Tarelkin of ROSCOSMOS on a five-month mission aboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

An innovative multi dof TMD system for motorcycle handlebars designed to reduce structural vibrations and human exposure

NASA Astrophysics Data System (ADS)

Agostoni, S.; Cheli, F.; Leo, E.; Pezzola, M.

2012-08-01

Motor vehicle ride comfort is mainly affected by reciprocating engine inertia unbalances. These forces are transmitted to the driver through the main frame, the engine mounts, and the auxiliary sub systems—all components with which he physically comes into contact. On-road traction vehicle engines are mainly characterized by transient exercise. Thus, an excitation frequency range from 800 RPM (≈15 Hz for stationary vehicles) up to 15,000 RPM (≈250 Hz as a cut off condition) occurs. Several structural resonances are induced by the unbalancing forces spectrum, thus exposing the driver to amplified vibrations. The aim of this research is to reduce driver vibration exposure, by acting on the modal response of structures with which the driver comes into contact. An experimental methodology, capable of identifying local vibration modes was developed. The application of this methodology on a reference vehicle allows us to detect if/when/how the above mentioned resonances are excited. Numerical models were used to study structural modifications. In this article, a handlebar equipped with an innovative multi reciprocating tuned mass damper was optimized. All structural modifications were designed, developed and installed on a vehicle. Modal investigations were then performed in order to predict modification efficiency. Furthermore, functional solution efficiency was verified during sweep tests performed on a target vehicle, by means of a roller bench capable of replicating on-road loads. Three main investigation zones of the vehicle were detected and monitored using accelerometers: (1) engine mounts, to characterize vibration emissions; (2) bindings connecting the engine to the frame, in order to detect vibration transfer paths, with particular attention being paid to local dynamic amplifications due to compliances and (3) the terminal components with which the driver comes into contact.

Optimization to reduce fuel consumption in charge depleting mode

DOEpatents

Roos, Bryan Nathaniel; Martini, Ryan D.

2014-08-26

A powertrain includes an internal combustion engine, a motor utilizing electrical energy from an energy storage device, and a plug-in connection. A Method for controlling the powertrain includes monitoring a fuel cut mode, ceasing a fuel flow to the engine based upon the fuel cut mode, and through a period of operation including acceleration of the powertrain, providing an entirety of propelling torque to the powertrain with the electrical energy from the energy storage device based upon the fuel cut mode.

Current status and biotechnological advances in genetic engineering of ornamental plants.

PubMed

Azadi, Pejman; Bagheri, Hedayat; Nalousi, Ayoub Molaahmad; Nazari, Farzad; Chandler, Stephen F

2016-11-01

Cut flower markets are developing in many countries as the international demand for cut flowers is rapidly growing. Developing new varieties with modified characteristics is an important aim in floriculture. Production of transgenic ornamental plants can shorten the time required in the conventional breeding of a cultivar. Biotechnology tools in combination with conventional breeding methods have been used by cut flower breeders to change flower color, plant architecture, post-harvest traits, and disease resistance. In this review, we describe advances in genetic engineering that have led to the development of new cut flower varieties. Copyright © 2016 Elsevier Inc. All rights reserved.

Improved Concrete Cutting and Excavation Capabilities for Crater Repair, Phase 1

DTIC Science & Technology

2014-04-01

manageable pieces, it is not recommended for the ADR process because of the requirement for additional supporting equipment - the air compressor ... Air Force Civil Engineer Center Tyndall Air Force Base, FL 32403-5319 ERDC/GSL TR-14-8 ii Abstract The US Army Engineer Research and...Development Center was tasked by the US Air Force Civil Engineer Center to improve the saw cutting and excavation production rates of crater repairs in thick

CUTS FOR MTR EXCAVATION ILLUSTRATE SEDIMENTARY MANTLE OF SOIL AND ...

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

CUTS FOR MTR EXCAVATION ILLUSTRATE SEDIMENTARY MANTLE OF SOIL AND GRAVEL OVERLAYING LAVA ROCK FIFTY FEET BELOW. SAGEBRUSH HAS BEEN SCOURED FROM REST OF SITE. CAMERA PROBABLY FACES SOUTHWEST. INL NEGATIVE NO. 67. Unknown Photographer, 6/4/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Engineering the shape and structure of materials by fractal cut.

PubMed

Cho, Yigil; Shin, Joong-Ho; Costa, Avelino; Kim, Tae Ann; Kunin, Valentin; Li, Ju; Lee, Su Yeon; Yang, Shu; Han, Heung Nam; Choi, In-Suk; Srolovitz, David J

2014-12-09

In this paper we discuss the transformation of a sheet of material into a wide range of desired shapes and patterns by introducing a set of simple cuts in a multilevel hierarchy with different motifs. Each choice of hierarchical cut motif and cut level allows the material to expand into a unique structure with a unique set of properties. We can reverse-engineer the desired expanded geometries to find the requisite cut pattern to produce it without changing the physical properties of the initial material. The concept was experimentally realized and applied to create an electrode that expands to >800% the original area with only very minor stretching of the underlying material. The generality of our approach greatly expands the design space for materials so that they can be tuned for diverse applications.

KSC-07pd3624

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, a technician checks test wiring spliced into an electrical harness in space shuttle Atlantis' aft main engine compartment connected with the engine cut-off, or ECO, system. The test wiring leads to the interior of the mobile launcher platform where the Time Domain Reflectometry, or TDR, test equipment will be located to test the sensor system. The shuttle's planned launches on Dec. 6 and Dec. 9 were postponed because of false readings from the part of the ECO system that monitors the liquid hydrogen section of the tank. The liftoff date from NASA's Kennedy Space Center, Florida, is now targeted for Jan. 10, depending on the resolution of the problem in the fuel sensor system. Photo credit: NASA/Kim Shiflett

KSC-07pd3623

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, a technician checks test wiring spliced into an electrical harness in space shuttle Atlantis' aft main engine compartment connected with the engine cut-off, or ECO, system. The test wiring leads to the interior of the mobile launcher platform where the Time Domain Reflectometry, or TDR, test equipment will be located to test the sensor system. The shuttle's planned launches on Dec. 6 and Dec. 9 were postponed because of false readings from the part of the ECO system that monitors the liquid hydrogen section of the tank. The liftoff date from NASA's Kennedy Space Center, Florida, is now targeted for Jan. 10, depending on the resolution of the problem in the fuel sensor system. Photo credit: NASA/Kim Shiflett

EDIN design study alternate space shuttle booster replacement concepts. Volume 2: Design simulation results

NASA Technical Reports Server (NTRS)

Demakes, P. T.; Hirsch, G. N.; Stewart, W. A.; Glatt, C. R.

1976-01-01

Historical weight estimating relationships were developed for the liquid rocket booster (LRB) using Saturn technology, and modified as required to support the EDIN05 study. Mission performance was computed using February 1975 shuttle configuration groundrules to allow reasonable comparison of the existing shuttle with the EDIN05 designs. The launch trajectory was constrained to pass through both the RTLS/AOA and main engine cut-off points. Performance analysis was based on a point design trajectory model which optimized initial tilt rate and exo-atmospheric pitch profile. A gravity turn was employed during the boost phase in place of the shuttle angle-of-attack profile. Engine throttling add/or shutdown was used to constrain dynamic pressure and/or longitudinal acceleration where necessary.

KSC-07pd3625

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, a technician checks test wiring spliced into an electrical harness in space shuttle Atlantis' aft main engine compartment connected with the engine cut-off, or ECO, system. The test wiring leads to the interior of the mobile launcher platform where the Time Domain Reflectometry, or TDR, test equipment will be located to test the sensor system. The shuttle's planned launches on Dec. 6 and Dec. 9 were postponed because of false readings from the part of the ECO system that monitors the liquid hydrogen section of the tank. The liftoff date from NASA's Kennedy Space Center, Florida, is now targeted for Jan. 10, depending on the resolution of the problem in the fuel sensor system. Photo credit: NASA/Kim Shiflett

The Lick-Gaertner automatic measuring system

NASA Technical Reports Server (NTRS)

Vasilevskis, S.; Popov, W. A.

1971-01-01

The Lick-Gaertner automatic equipment has been designed mainly for the measurement of stellar proper motions with reference to galaxies, and consists of two main components: the survey machine and the automatic measuring engine. The survey machine is used for initial inspection and selection of objects for subsequent measurement. Two plates, up to 17 x 17 inches each, are surveyed simultaneously by means of projection on a screen. The approximate positions of objects selected are measured by two optical screws: helical lines cut through an aluminum coating on glass cylinders. These approximate coordinates to a precision of the order of 0.03mm are transmitted to a card punch by encoders connected with the cylinders.

76 FR 35378 - Installation and Use of Engine Cut-Off Switches on Recreational Vehicles

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-17

... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Parts 175 and 183 [Docket No. USCG-2009-0206] RIN 1825-AB34 Installation and Use of Engine Cut-Off Switches on Recreational Vehicles Correction Proposed Rule document 2011-14140 was inadvertently published in the Rules section of the issue of June 8...

Beam engineering for zero conicity cutting and drilling with ultra fast laser (Conference Presentation)

NASA Astrophysics Data System (ADS)

Letan, Amelie; Mishchik, Konstantin; Audouard, Eric; Hoenninger, Clemens; Mottay, Eric P.

2017-03-01

With the development of high average power, high repetition rate, industrial ultrafast lasers, it is now possible to achieve a high throughput with femtosecond laser processing, providing that the operating parameters are finely tuned to the application. Femtosecond lasers play a key role in these processes, due to their ability to high quality micro processing. They are able to drill high thickness holes (up to 1 mm) with arbitrary shapes, such as zero-conicity or even inversed taper, but can also perform zero-taper cutting. A clear understanding of all the processing steps necessary to optimize the processing speed is a main challenge for industrial developments. Indeed, the laser parameters are not independent of the beam steering devices. Pulses energy and repetition rate have to be precisely adjusted to the beam angle with the sample, and to the temporal and spatial sequences of pulses superposition. The purpose of the present work is to identify the role of these parameters for high aspect ratio drilling and cutting not only with experimental trials, but also with numerical estimations, using a simple engineering model based on the two temperature description of ultra-fast ablation. Assuming a nonlinear logarithmic response of the materials to ultrafast pulses, each material can be described by only two adjustable parameters. Simple assumptions allow to predict the effect of beam velocity and non-normal incident beams to estimate profile shapes and processing time.

Modal analysis of an aircraft engine fan noise

NASA Astrophysics Data System (ADS)

Gorodkova, Natalia; Chursin, Valeriy; Bersenev, Yuliy; Burdakov, Ruslan; Siner, Aleksandr; Viskova, Tatiana

2016-10-01

The fan is one of the main noise sources of an aircraft engine. To reduce fan noise and provide liner optimization in the inlet it is necessary to research modal structure of the fan noise. The present paper contains results of acoustic tests on installation for mode generation that consists of 34-channel generator and the inlet updated for mounting of 100 microphones, the experiments were provided in new anechoic chamber of Perm National Research Polytechnic University, the engine with the same inlet was also tested in the open test bench conditions, and results of the fan noise modal structure are presented. For modal structure educting, all 100 channels were synchronously registered in a given frequency range. The measured data were analyzed with PULSE analyzer using fast Fourier transform with a frequency resolution 8..16 Hz. Single modes with numbers from 0 to 35 at frequencies 500; 630; 800; 1000; 1250; 1600 Hz and different combinations of modes at frequencies 1000, 1600, 2000, 2500 Hz were set during tests. Modes with small enough numbers are generated well on the laboratory installation, high-number modes generate additional modes caused by a complicated interference pattern of sound field in the inlet. Open test bench results showed that there are also a lot of harmonic components at frequencies lower than fan BPF. Under 0.65 of cut off there is only one distinct mode, other modes with close and less numbers appear from 0.7 of cut off and above. At power regimes 0.76 and 0.94 of cut off the highest mode also changes from positive to negative mode number area. Numbers of the highest modes change smoothly enough with the growth of power regime. At power regimes with Mach>1 (0.7 of cut off and above) on circumference of blade wheel there is a well-defined noise of shock waves at rotor frequency harmonics that appears at the range between the first rotor frequency and fan blade passing frequency (BPF). It is planned to continue researching of sound field modal structure with acoustic measurements in near and far field.

KSC-05PD-1586

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. On the table is a refurbished, spare orbiter point sensor chassis and a motherboard. Components are being tested to determine why one of the four liquid hydrogen tank low-level fuel cut-off sensors failed in a routine prelaunch check during the launch countdown July 13. The failure caused mission managers to scrub Discovery's first launch attempt. The sensor protects the Shuttle's main engines by triggering their shutdown in the event fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank (ET).

Understanding and Writing G & M Code for CNC Machines

ERIC Educational Resources Information Center

Loveland, Thomas

2012-01-01

In modern CAD and CAM manufacturing companies, engineers design parts for machines and consumable goods. Many of these parts are cut on CNC machines. Whether using a CNC lathe, milling machine, or router, the ideas and designs of engineers must be translated into a machine-readable form called G & M Code that can be used to cut parts to precise…

Optimization of self-aligned double patterning (SADP)-compliant layout designs using pattern matching for sub-20nm metal routing

NASA Astrophysics Data System (ADS)

Wang, Lynn T.-N.; Schroeder, Uwe Paul; Madhavan, Sriram

2017-03-01

A pattern-based methodology for optimizing SADP-compliant layout designs is developed based on identifying cut mask patterns and replacing them with pre-characterized fixing solutions. A pattern-based library of difficult-tomanufacture cut patterns with pre-characterized fixing solutions is built. A pattern-based engine searches for matching patterns in the decomposed layouts. When a match is found, the engine opportunistically replaces the detected pattern with a pre-characterized fixing solution. The methodology was demonstrated on a 7nm routed metal2 block. A small library of 30 cut patterns increased the number of more manufacturable cuts by 38% and metal-via enclosure by 13% with a small parasitic capacitance impact of 0.3%.

KSC-05PD-1592

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Media gather in the television studio at the NASA News Center to hear members of the Mission Management Team reveal aspects of the troubleshooting and testing being done on the liquid hydrogen tank low-level fuel cut-off sensor. On the stage at right are (from left) Wayne Hale, Space Shuttle deputy program manager; John Muratore, manager of Systems Engineering and Integration for the Space Shuttle Program; and Mike Wetmore, director of Space Shuttle Processing. The sensor failed a routine prelaunch check during the launch countdown July 13, causing mission managers to scrub Discovery's first launch attempt. The sensor protects the Shuttle's main engines by triggering their shutdown in the event fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank (ET).

KSC-07pd3629

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, a technician prepares a cable from an electrical harness in space shuttle Atlantis' aft main engine compartment connected with the engine cut-off, or ECO, system leading into the tail mast. The test wiring leads from the tail mast to the interior of the mobile launcher platform where the Time Domain Reflectometry, or TDR, test equipment will be located to test the sensor system. The shuttle's planned launches on Dec. 6 and Dec. 9 were postponed because of false readings from the part of the ECO system that monitors the liquid hydrogen section of the tank. The liftoff date from NASA's Kennedy Space Center, Florida, is now targeted for Jan. 10, depending on the resolution of the problem in the fuel sensor system. Photo credit: NASA/Kim Shiflett

KSC-07pd3628

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, cables lead from an electrical harness in space shuttle Atlantis' aft main engine compartment connected with the engine cut-off, or ECO, system into the tail mast. The test wiring leads from the tail mast to the interior of the mobile launcher platform where the Time Domain Reflectometry, or TDR, test equipment will be located to test the sensor system. The shuttle's planned launches on Dec. 6 and Dec. 9 were postponed because of false readings from the part of the ECO system that monitors the liquid hydrogen section of the tank. The liftoff date from NASA's Kennedy Space Center, Florida, is now targeted for Jan. 10, depending on the resolution of the problem in the fuel sensor system. Photo credit: NASA/Kim Shiflett

KSC-07pd3627

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, cables lead from an electrical harness in space shuttle Atlantis' aft main engine compartment connected with the engine cut-off, or ECO, system into the tail mast. The test wiring leads from the tail mast to the interior of the mobile launcher platform where the Time Domain Reflectometry, or TDR, test equipment will be located to test the sensor system. The shuttle's planned launches on Dec. 6 and Dec. 9 were postponed because of false readings from the part of the ECO system that monitors the liquid hydrogen section of the tank. The liftoff date from NASA's Kennedy Space Center, Florida, is now targeted for Jan. 10, depending on the resolution of the problem in the fuel sensor system. Photo credit: NASA/Kim Shiflett

EDIN design study alternate space shuttle booster replacement concepts. Volume 1: Engineering analysis

NASA Technical Reports Server (NTRS)

Demakes, P. T.; Hirsch, G. N.; Stewart, W. A.; Glatt, C. R.

1976-01-01

The use of a recoverable liquid rocket booster (LRB) system to replace the existing solid rocket booster (SRB) system for the shuttle was studied. Historical weight estimating relationships were developed for the LRB using Saturn technology and modified as required. Mission performance was computed using February 1975 shuttle configuration groundrules to allow reasonable comparison of the existing shuttle with the study designs. The launch trajectory was constrained to pass through both the RTLS/AOA and main engine cut off points of the shuttle reference mission 1. Performance analysis is based on a point design trajectory model which optimizes initial tilt rate and exoatmospheric pitch profile. A gravity turn was employed during the boost phase in place of the shuttle angle of attack profile. Engine throttling add/or shutdown was used to constrain dynamic pressure and/or longitudinal acceleration where necessary. Four basic configurations were investigated: a parallel burn vehicle with an F-1 engine powered LRB; a parallel burn vehicle with a high pressure engine powered LRB; a series burn vehicle with a high pressure engine powered LRB. The relative sizes of the LRB and the ET are optimized to minimize GLOW in most cases.

Engineering control technologies to reduce occupational silica exposures in masonry cutting and tuckpointing.

PubMed

Meeker, John D; Cooper, Michael R; Lefkowitz, Daniel; Susi, Pam

2009-01-01

A number of tasks in construction generate worker overexposures to respirable crystalline silica dust, which is a significant contributor to occupational mortality and morbidity. This study evaluated the performance of commercially available engineering controls used in dusty construction tasks commonly performed by bricklayers. Local exhaust ventilation (LEV) controls for a portable abrasive cutter and for tuckpointing grinders were examined at a bricklayers' training center, as were two stationary wet saws. Personal breathing zone air samples were collected with and without the use of LEV or water suppression during simulated concrete block cutting, brick cutting, and tuckpointing. Compared with the use of no exposure control during block and brick cutting, the portable LEV unit significantly reduced mean respirable quartz exposures by 96% for block cutting and 91% for brick cutting (p < 0.01). The use of stationary wet saws was also associated with 91% reductions in exposure (p < 0.01). For tuckpointing, the reductions in mean respirable quartz concentrations were between 91% and 93% with the LEV controls (p < 0.05). Reductions of up to 96% in mean respirable quartz concentration were observed between control and no-control scenarios. These reductions with commercially available off-the-shelf tools demonstrate the effectiveness of engineering control interventions to reduce crystalline silica exposures in construction. Strategies to further improve control performance and approaches for increasing control interventions in construction are needed.

Expedition 33 Crew Hair Cut

NASA Image and Video Library

2012-10-21

Expedition 33 Soyuz Commander Oleg Novitskiy gets his hair cut at the Cosmonaut Hotel, on Sunday, October 21, 2012, at the Baikonur Cosmodrome in Kazakhstan. Launch of the Soyuz rocket is scheduled for October 23 and will send Expedition 33/34 Flight Engineer Kevin Ford of NASA, Soyuz Commander Oleg Novitskiy and Flight Engineer Evgeny Tarelkin of ROSCOSMOS on a five-month mission aboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

Three-Dimensional Profiles Using a Spherical Cutting Bit: Problem Solving in Practice

ERIC Educational Resources Information Center

Ollerton, Richard L.; Iskov, Grant H.; Shannon, Anthony G.

2002-01-01

An engineering problem concerned with relating the coordinates of the centre of a spherical cutting tool to the actual cutting surface leads to a potentially rich example of problem-solving techniques. Basic calculus, Lagrange multipliers and vector calculus techniques are employed to produce solutions that may be compared to better understand…

Mamdani-Fuzzy Modeling Approach for Quality Prediction of Non-Linear Laser Lathing Process

NASA Astrophysics Data System (ADS)

Sivaraos; Khalim, A. Z.; Salleh, M. S.; Sivakumar, D.; Kadirgama, K.

2018-03-01

Lathing is a process to fashioning stock materials into desired cylindrical shapes which usually performed by traditional lathe machine. But, the recent rapid advancements in engineering materials and precision demand gives a great challenge to the traditional method. The main drawback of conventional lathe is its mechanical contact which brings to the undesirable tool wear, heat affected zone, finishing, and dimensional accuracy especially taper quality in machining of stock with high length to diameter ratio. Therefore, a novel approach has been devised to investigate in transforming a 2D flatbed CO2 laser cutting machine into 3D laser lathing capability as an alternative solution. Three significant design parameters were selected for this experiment, namely cutting speed, spinning speed, and depth of cut. Total of 24 experiments were performed with eight (8) sequential runs where they were then replicated three (3) times. The experimental results were then used to establish Mamdani - Fuzzy predictive model where it yields the accuracy of more than 95%. Thus, the proposed Mamdani - Fuzzy modelling approach is found very much suitable and practical for quality prediction of non-linear laser lathing process for cylindrical stocks of 10mm diameter.

Remote-Sensing Survey of the Atchafalaya Basin Main Channel, Atchafalaya Channel Training Project, Sts. Martin and Mary Parishes, Louisiana

DTIC Science & Technology

1991-11-01

Just above Cornay’s Bridge they sunk the steamer Flycatcher and a schooner loaded with bricks, plus live oak trees were cut down and thrown into the...contour level) (Feet) Single Objects Engine camshaft 20 fi x 2 m 45 45 x 50 feet 15 Cas’ Iron soil pipe 10 ft long. 100 lbs 1407 45 x 65 feet 4 Iron...hitting any of the numerous fallen trees , snags, submerged logs, shallow sand bars, etc., 52 Chapter 3. Remote-Sensing Survey which occur along much of the

KSC-05PD-1575

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. The gate is open to Launch Pad 39B where Space Shuttle Discovery remains on the pad after scrub of Return to Flight mission STS-114. The July 13 mission was scrubbed when a low-level fuel cut-off sensor for the liquid hydrogen tank inside the External Tank failed a routine prelaunch check during the countdown July 13, causing mission managers to scrub Discovery's first launch attempt. The sensor protects the Shuttle's main engines by triggering their shutdown in the event fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank (ET).

KSC-05PD-1585

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. On the table is a mother board with electronic components that could be used in a spare orbiter point sensor chassis. Faulty readings in the liquid hydrogen tank low- level fuel cut-off sensor are being investigated because one of the four sensors failed a routine prelaunch check during the launch countdown July 13, causing mission managers to scrub Discovery's first launch attempt. The sensor protects the Shuttle's main engines by triggering their shutdown in the event fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank (ET).

System Identification of X-33 Neural Network

NASA Technical Reports Server (NTRS)

Aggarwal, Shiv

2003-01-01

Modern flight control research has improved spacecraft survivability as its goal. To this end we need to have a failure detection system on board. In case the spacecraft is performing imperfectly, reconfiguration of control is needed. For that purpose we need to have parameter identification of spacecraft dynamics. Parameter identification of a system is called system identification. We treat the system as a black box which receives some inputs that lead to some outputs. The question is: what kind of parameters for a particular black box can correlate the observed inputs and outputs? Can these parameters help us to predict the outputs for a new given set of inputs? This is the basic problem of system identification. The X33 was supposed to have the onboard capability of evaluating the current performance and if needed to take the corrective measures to adapt to desired performance. The X33 is comprised of both rocket and aircraft vehicle design characteristics and requires, in general, analytical methods for evaluating its flight performance. Its flight consists of four phases: ascent, transition, entry and TAEM (Terminal Area Energy Management). It spends about 200 seconds in ascent phase, reaching an altitude of about 180,000 feet and a speed of about 10 to 15 Mach. During the transition phase which lasts only about 30 seconds, its altitude may increase to about 190,000 feet but its speed is reduced to about 9 Mach. At the beginning of this phase, the Main Engine is Cut Off (MECO) and the control is reconfigured with the help of aerosurfaces (four elevons, two flaps and two rudders) and reaction control system (RCS). The entry phase brings down the altitude of X33 to about 90,000 feet and its speed to about Mach 3. It spends about 250 seconds in this phase. Main engine is still cut off and the vehicle is controlled by complex maneuvers of aerosurfaces. The last phase TAEM lasts for about 450 seconds and the altitude and speed, both are reduced to zero. The present attempt, as a start, focuses only on the entry phase. Since the main engine remains cut off in this phase, there is no thrust acting on the system. This considerably simplifies the equations of motion. We introduce another simplification by assuming the system to be linear after some non-linearities are removed analytically from our consideration. Under these assumptions, the problem could be solved by Classical Statistics by employing the least sum of squares approach. Instead we chose to use the Neural Network method. This method has many advantages. It is modern, more efficient, can be adapted to work even when the assumptions are diluted. In fact, Neural Networks try to model the human brain and are capable of pattern recognition.

Reservoir management cost-cutting

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

Gulati, M.S.

This article by Mohinder S. Gulati, Chief Engineer, Unocal Geothermal Operations, discusses cost cutting in geothermal reservoir management. The reservoir engineer or geoscientist can make a big difference in the economical outcome of a project by improving well performance and thus making geothermal energy more competitive in the energy marketplace. Bringing plants online in less time and proving resources to reduce the cycle time are some of the ways to reduce reservoir management costs discussed in this article.

Investigation of the current requirements engineering practices among software developers at the Universiti Utara Malaysia Information Technology (UUMIT) centre

NASA Astrophysics Data System (ADS)

Hussain, Azham; Mkpojiogu, Emmanuel O. C.; Abdullah, Inam

2016-08-01

Requirements Engineering (RE) is a systemic and integrated process of eliciting, elaborating, negotiating, validating and managing of the requirements of a system in a software development project. UUM has been supported by various systems developed and maintained by the UUM Information Technology (UUMIT) Centre. The aim of this study was to assess the current requirements engineering practices at UUMIT. The main problem that prompted this research is the lack of studies that support software development activities at the UUMIT. The study is geared at helping UUMIT produce quality but time and cost saving software products by implementing cutting edge and state of the art requirements engineering practices. Also, the study contributes to UUM by identifying the activities needed for software development so that the management will be able to allocate budget to provide adequate and precise training for the software developers. Three variables were investigated: Requirement Description, Requirements Development (comprising: Requirements Elicitation, Requirements Analysis and Negotiation, Requirements Validation), and Requirement Management. The results from the study showed that the current practice of requirement engineering in UUMIT is encouraging, but still need further development and improvement because a few RE practices were seldom practiced.

KSC-05PD-1590

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. Media gather in the television studio at the NASA News Center to hear members of the Mission Management Team reveal aspects of the troubleshooting and testing being done on the liquid hydrogen tank low-level fuel cut-off sensor. On the stage at right are (from left) Bruce Buckingham, NASA news chief; Wayne Hale, Space Shuttle deputy program manager; John Muratore, manager of Systems Engineering and Integration for the Space Shuttle Program; and Mike Wetmore, director of Space Shuttle Processing. The sensor failed a routine prelaunch check during the launch countdown July 13, causing mission managers to scrub Discovery's first launch attempt. The sensor protects the Shuttle's main engines by triggering their shutdown in the event fuel runs unexpectedly low. The sensor is one of four inside the liquid hydrogen section of the External Tank (ET).

Status of Goldstone solar energy system study of the first Goldstone energy project

NASA Technical Reports Server (NTRS)

Lansing, F. L.

1977-01-01

The results reached by the DSN engineering section and private consultants in the review of the initial plan of the Golstone Energy Project are summarized. The main objectives were in the areas of energy conservation and the application of solar-driven systems for power and hydrogen generation. This summary will provide background data for management planning decisions both to the DSN engineering section and other organizations planning a similar program. The review showed that an add-on solar driven absorption refrigeration unit with its associated changes to the existing system was not cost-effective, having a payback period of 29 years. Similar economically unattractive results were found for both a solar-hydrogen and a wind-hydrogen generation plant. However, cutting the hydrogen generation linkage from this plant improved its economic feasibility.

75 FR 70096 - Airworthiness Directives; General Electric Company (GE) CT7-9C and -9C3 Turboprop Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

... generator turbine (GGT) shafts for nonconforming land balance-cuts, and if found, removing the shaft from... detect nonconforming GGT shaft land balance-cuts, which could result in the shaft failing before its..., for nonconforming land balance- cuts, and if found, replacing the shaft. Comments We gave the public...

Energy Efficient Engine acoustic supporting technology report

NASA Technical Reports Server (NTRS)

Lavin, S. P.; Ho, P. Y.

1985-01-01

The acoustic development of the Energy Efficient Engine combined testing and analysis using scale model rigs and an integrated Core/Low Spool demonstration engine. The scale model tests show that a cut-on blade/vane ratio fan with a large spacing (S/C = 2.3) is as quiet as a cut-off blade/vane ratio with a tighter spacing (S/C = 1.27). Scale model mixer tests show that separate flow nozzles are the noisiest, conic nozzles the quietest, with forced mixers in between. Based on projections of ICLS data the Energy Efficient Engine (E3) has FAR 36 margins of 3.7 EPNdB at approach, 4.5 EPNdB at full power takeoff, and 7.2 EPNdB at sideline conditions.

Sixty Years of Silviculture in a Northern Conifer Forest in Maine, USA

Treesearch

Nicole Rogers; Laura Kenefic; Mindy Crandall; Robert Seymour; Paul Sendak

2017-01-01

In 1950, the US Forest Service initiated a cutting practice level (CPL) study on the Penobscot Experimental Forest in Maine on the basis of findings of a national appraisal of forestland management. Silvicultural treatments, including the selection system with 5- and 15-year cutting cycles, fixed diameter-limit cutting, and variants of commercial clearcutting, were...

Power control system for a hot gas engine

DOEpatents

Berntell, John O.

1986-01-01

A power control system for a hot gas engine of the type in which the power output is controlled by varying the mean pressure of the working gas charge in the engine has according to the present invention been provided with two working gas reservoirs at substantially different pressure levels. At working gas pressures below the lower of said levels the high pressure gas reservoir is cut out from the control system, and at higher pressures the low pressure gas reservoir is cut out from the system, thereby enabling a single one-stage compressor to handle gas within a wide pressure range at a low compression ratio.

STS-114: Engine Cut-Off Sensors Are a No-Go: Teaching Notes for NASA Case Study

NASA Technical Reports Server (NTRS)

Ransom, Khadijah S.; Johnson, Grace K.

2013-01-01

This case study format is intended to simulate the experience of facing the same difficult challenges and making the same critical decisions as managers, engineers, and scientists in the Space Shuttle Program. It has been designed for use in the classroom setting to help students develop skills related to decision-making. Students will read about the engine cut-off sensor anomaly which created challenges during the STS-114 mission and have the opportunity to make decisions as lead NASA engineers and Mission Management Team members. Included within this document are three case study presentation options - class discussion, group activity, and open-ended research. Please read the full case prior to in-class presentation to allow ample time for students' analysis and reflection, as well as to prepare additional questions. activities or exercises, material selection, etc. Depending upon the setting of your presentation and the number of participants, please choose at least one presentation format beforehand and plan accordingly. You may expect the following learning objectives by using the proposed formats. Learning Objectives: To enable students to experience the responsibilities of NASA management, engineers, and analysis; to discover possible procedures for investigating system anomalies; to become familiar with the liquid hydrogen low level engine cut-off sensor, including its function, connecting components, and location within the Space Shuttle; and to encourage critical analysis and stimulating discussion of Space Shuttle mission challenges.

Sun, Sand and Water: A History of the Jacksonville District U.S. Army Corps of Engineers 1821-1975

DTIC Science & Technology

1981-01-01

plan envisioned a dredged cut through the barrier beach to Banana River. On the river there would be a turning basin with terminal facilities, and...intracoastal canal to the west This canal would cut through Merritt Island, which separated Indian River from Banana River.6 District Engineer, Colonel...canal, guarded by two jetties, through the barrier land from the 27 -foot contour line in the Atlantic to a 27 -foot turning basin in the Banana

Popham Beach, Maine: An example of engineering activity that saved beach property without harming the beach

NASA Astrophysics Data System (ADS)

Kelley, Joseph T.

2013-10-01

Beach and property erosion on coasts is a widespread and chronic problem. Historical approaches to this issue, including seawalls and sand replenishment, are often inappropriate or too expensive. In Maine, seawalls were banned in 1983 and replenishment is too costly to employ. Replacement of storm-damaged buildings is also not allowed, and a precedent case on Popham Beach, Maine required that the owner remove an unpermitted building from a site where an earlier structure was damaged. When the most popular park in Maine, Popham Beach State Park, experienced inlet associated erosion that threatened park infrastructure (a bathhouse), temporary measures were all that the law allowed. Because it was clear that the inlet channel causing the erosion would eventually change course, the state opted to erect a temporary seawall with fallen trees at the site. This may or may not have slowed the erosion temporarily, but reassured the public that "something was being done". Once a storm cut a new tidal inlet channel and closed off the old one, tidal water still entered the former channel and continued to threaten the bathhouse. To ultimately save the property, beach scraping was employed. Sand was scraped from the lower beach to construct a sand berm that deflected the tidal current away from the endangered property. This action created enough time for natural processes to drive the remains of the former spit onto the beach and widen it significantly. Whereas many examples of engineering practices exist that endanger instead of saving beaches, this example is one of an appropriate engineering effort to rescue unwisely located beach-front property.

STS-87 Mission Specialist Chawla talks to the media during TCDT

NASA Technical Reports Server (NTRS)

1997-01-01

Kalpana Chawla, Ph.D., a mission specialist of the STS-87 crew, participates in a news briefing at Launch Pad 39B during the Terminal Countdown Demonstration Test (TCDT) at Kennedy Space Center (KSC). First-time Shuttle flier Dr. Chawla reported for training as an astronaut at Johnson Space Center in 1995. She has a doctorate in aerospace engineering from the University of Colorado. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay. STS-87 is scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from pad 39B at KSC.

KSC-97PC1603

NASA Image and Video Library

1997-11-04

Kalpana Chawla, Ph.D., a mission specialist of the STS-87 crew, participates in a news briefing at Launch Pad 39B during the Terminal Countdown Demonstration Test (TCDT) at Kennedy Space Center (KSC). First-time Shuttle flier Dr. Chawla reported for training as an astronaut at Johnson Space Center in 1995. She has a doctorate in aerospace engineering from the University of Colorado. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay. STS-87 is scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from pad 39B at KSC

75 FR 43099 - Airworthiness Directives; General Electric Company (GE) CT7-9C and -9C3 Turboprop Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-23

... GGT shaft for nonconforming land balance-cuts, and if found, removing the shaft from service. This... nonconforming GGT shaft land balance-cuts, which could result in the shaft failing before its published life... reports of 21 nonconforming land balance-cuts on GGT shafts, P/N 6068T44P02. The nonconforming land...

STS-88 Mission Specialists Currie and Ross inside Endeavour

NASA Technical Reports Server (NTRS)

1998-01-01

STS-88 Mission Specialists Nancy J. Currie, Ph.D., (back) and Jerry L. Ross (front) check over equipment inside orbiter Endeavour during Terminal Countdown Demonstration Activities (TCDT). The TCDT includes mission familiarization activities, emergency egress training, and the simulated main engine cut-off exercise. Mission STS-88 is targeted for launch on Dec. 3, 1998. It is the first U.S. flight for the assembly of the International Space Station and will carry the Unity connecting module. Unity will be mated with the already orbiting Russian-built Zarya control module. The 12-day mission includes three planned spacewalks to connect power, data and utility lines and install exterior equipment.

Engineering specification and system design for CAD/CAM of custom shoes: UMC project effort

NASA Technical Reports Server (NTRS)

Bao, Han P.

1990-01-01

Further experimentations were made to improve the design and fabrication techniques of the integrated sole. The sole design is shown to be related to the foot position requirements and the actual shape of the foot including presence of neurotropic ulcers or other infections. Factors for consideration were: heel pitch, balance line, and rigidity conditions of the foot. Machining considerations were also part of the design problem. Among these considerations, widths of each contour, tool motion, tool feed rate, depths of cut, and slopes of cut at the boundary were the key elements. The essential fabrication techniques evolved around the idea of machining a mold then, using quick-firm latex material, casting the sole through the mold. Two main mold materials were experimented with: plaster and wood. Plaster was very easy to machine and shape but could barely support the pressure in the hydraulic press required by the casting process. Wood was found to be quite effective in terms of relative cost, strength, and surface smoothness except for the problem of cutting against the fibers which could generate ragged surfaces. The programming efforts to convert the original dBase programs into C programs so that they could be executed on the SUN Computer at North Carolina State University are discussed.

Network Analysis of Conversation Data for Engineering Professional Skills Assessment. Research Report. ETS RR-17-59

ERIC Educational Resources Information Center

Zhu, Mengxiao; Zhang, Mo

2017-01-01

In this paper, we examine the student group discussion processes in a scenario-based assessment of engineering professional skills called Engineering Professional Skills Assessment (EPSA). In the assessment, the students were evaluated through a discussion on a scenario related to an engineering problem with no clear-cut solution. We applied…

Tool path strategy and cutting process monitoring in intelligent machining

NASA Astrophysics Data System (ADS)

Chen, Ming; Wang, Chengdong; An, Qinglong; Ming, Weiwei

2018-06-01

Intelligent machining is a current focus in advanced manufacturing technology, and is characterized by high accuracy and efficiency. A central technology of intelligent machining—the cutting process online monitoring and optimization—is urgently needed for mass production. In this research, the cutting process online monitoring and optimization in jet engine impeller machining, cranio-maxillofacial surgery, and hydraulic servo valve deburring are introduced as examples of intelligent machining. Results show that intelligent tool path optimization and cutting process online monitoring are efficient techniques for improving the efficiency, quality, and reliability of machining.

Propagation of waves in elliptic ducts. A theoretical study. [in view of jet engine compressor noise reduction

NASA Technical Reports Server (NTRS)

Baskaran, S.

1974-01-01

The cut-off frequencies for high order circumferential modes were calculated for various eccentricities of an elliptic duct section. The problem was studied with a view to the reduction of jet engine compressor noise by elliptic ducts, instead of circular ducts. The cut-off frequencies for even functions decrease with increasing eccentricity. The third order eigen frequencies are oscillatory as the eccentricity increases for odd functions. The eigen frequencies decrease for higher order odd functions inasmuch as, for higher orders, they assume the same values as those for even functions. Deformation of a circular pipe into an elliptic one of sufficiently large eccentricity produces only a small reduction in the cut-off frequency, provided the area of the pipe section is kept invariable.

Probable effects on ground-water resources from construction of the proposed Grand River cut-off channel west of Lansing, Mich.

USGS Publications Warehouse

Ferris, John G.

1950-01-01

This memorandum summarize information brought out in correspondence between the office of the District Engineer of the Milwaukee District, U.S. Corps of Engineers, and the District Office of the Ground Water Branch of the U.S. Geological Survey at Lansing, Mich., concerning the probable effects on the ground-water resources of the Lansing area from the construction of a proposed flood-water cut-off channel for the Grand River to extend from Millett to Delta Mills, in Eaton County, Mich.

FY2016 Advanced Combustion Engine Annual Progress Report

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

None, None

The Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles.

FY2014 Advanced Combustion Engine Annual Progress Report

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

None

2015-03-01

The Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles.

ARC-2001-ACD01-0018

NASA Image and Video Library

2001-02-16

New Center Network Deployment ribbon Cutting: from left to right: Maryland Edwards, Code JT upgrade project deputy task manager; Ed Murphy, foundry networks systems engineer; Bohdan Cmaylo, Code JT upgrade project task manager, Scott Santiago, Division Chief, Code JT; Greg Miller, Raytheon Network engineer and Frank Daras, Raytheon network engineering manager.

FY2015 Advanced Combustion Engine Annual Progress Report

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

Singh, Gurpreet; Gravel, Roland M.; Howden, Kenneth C.

The Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles.

LDSD Test Device Arrives in Hawaii

NASA Image and Video Library

2014-05-28

Engineers unload ground support equipment for a June engineering test flight above Kauai, Hawaii. The test flight is part of NASA LDSD project, which is investigating cutting-edge landing technologies that could fly on future Mars missions.

High speed turning of compacted graphite iron using controlled modulation

NASA Astrophysics Data System (ADS)

Stalbaum, Tyler Paul

Compacted graphite iron (CGI) is a material which emerged as a candidate material to replace cast iron (CI) in the automotive industry for engine block castings. Its thermal and mechanical properties allow the CGI-based engines to operate at higher cylinder pressures and temperatures than CI-based engines, allowing for lower fuel emissions and increased fuel economy. However, these same properties together with the thermomechanical wear mode in the CGI-CBN system result in poor machinability and inhibit CGI from seeing wide spread use in the automotive industry. In industry, machining of CGI is done only at low speeds, less than V = 200 m/min, to avoid encountering rapid wear of the cutting tools during cutting. Studies have suggested intermittent cutting operations such as milling suffer less severe tool wear than continuous cutting. Furthermore, evidence that a hard sulfide layer which forms over the cutting edge in machining CI at high speeds is absent during machining CGI is a major factor in the difference in machinability of these material systems. The present study addresses both of these issues by modification to the conventional machining process to allow intermittent continuous cutting. The application of controlled modulation superimposed onto the cutting process -- modulation-assisted machining (MAM) -- is shown to be quite effective in reducing the wear of cubic boron nitride (CBN) tools when machining CGI at high machining speeds (> 500 m/min). The tool life is at least 20 times greater than found in conventional machining of CGI. This significant reduction in wear is a consequence of reduction in the severity of the tool-work contact conditions with MAM. The propensity for thermochemical wear of CBN is thus reduced. It is found that higher cutting speed (> 700 m/min) leads to lower tool wear with MAM. The MAM configuration employing feed-direction modulation appears feasible for implementation at high speeds and offers a solution to this challenging class of industrial machining applications. This study's approach is by series of high speed turning tests of CGI with CBN tools, comparing conventional machining to MAM for similar parameters otherwise, by tool wear measurements and machinability observations.

On-line fresh-cut lettuce quality measurement system using hyperspectral imaging

USDA-ARS?s Scientific Manuscript database

Lettuce, which is a main type of fresh-cut vegetable, has been used in various fresh-cut products. In this study, an online quality measurement system for detecting foreign substances on the fresh-cut lettuce was developed using hyperspectral reflectance imaging. The online detection system with a s...

Evaluation of alternative snow plow cutting edges.

DOT National Transportation Integrated Search

2009-05-01

With approximately 450 snow plow trucks, the Maine Department of Transportation (MaineDOT) uses in : excess of 10,000 linear feet of plow cutting edges each winter season. Using the 2008-2009 cost per linear : foot of $48.32, the Departments total co...

Influence of Cutting Parameters and Tool Wear on the Surface Integrity of Cobalt-Based Stellite 6 Alloy When Machined Under a Dry Cutting Environment

NASA Astrophysics Data System (ADS)

Yingfei, Ge; de Escalona, Patricia Muñoz; Galloway, Alexander

2017-01-01

The efficiency of a machining process can be measured by evaluating the quality of the machined surface and the tool wear rate. The research reported herein is mainly focused on the effect of cutting parameters and tool wear on the machined surface defects, surface roughness, deformation layer and residual stresses when dry milling Stellite 6, deposited by overlay on a carbon steel surface. The results showed that under the selected cutting conditions, abrasion, diffusion, peeling, chipping and breakage were the main tool wear mechanisms presented. Also the feed rate was the primary factor affecting the tool wear with an influence of 83%. With regard to the influence of cutting parameters on the surface roughness, the primary factors were feed rate and cutting speed with 57 and 38%, respectively. In addition, in general, as tool wear increased, the surface roughness increased and the deformation layer was found to be influenced more by the cutting parameters rather than the tool wear. Compressive residual stresses were observed in the un-machined surface, and when machining longer than 5 min, residual stress changed 100% from compression to tension. Finally, results showed that micro-crack initiation was the main mechanism for chip formation.

Stress Reconstruction Analysis of Wheel Saw Cut Tests and Evaluation of Reconstruction Procedure

DOT National Transportation Integrated Search

1993-09-01

The report is the fourth in a series of engineering studies on railroad vehicle wheel performance. The results of saw cut tests performed on one new and one used wheel designed for a fleet of multiple unit (MU) power cars are summarized and analyzed....

The Impact of Budget Cuts on Three Directorates of the National Science Foundation.

ERIC Educational Resources Information Center

General Accounting Office, Washington, DC.

This report provides comments and opinions from National Science Foundation (NSF) officials on proposed agency budget cuts which could affect three NSF Directorates: Science and Engineering; Biological, Behavioral, and Social Sciences; and Scientific, Technological, and International Affairs. Specific topics discussed focus on personnel levels,…

Expedition 21 Crew Members cut one another hair in the Destiny Laboratory

NASA Image and Video Library

2009-10-11

ISS021-E-005057 (11 Oct. 2009) --- Canadian Space Agency astronaut Robert Thirsk, Expedition 21 flight engineer, trims Russian cosmonaut Roman Romanenko's hair in the Destiny laboratory of the International Space Station. Thirsk used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Williams cuts his hair in the SM during Expedition 13

NASA Image and Video Library

2006-05-09

ISS013-E-17184 (9 May 2006) --- Astronaut Jeffrey N. Williams, Expedition 13 NASA space station science officer and flight engineer, trims his hair in the Zarya module of the International Space Station. Williams used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Curve Numbers for Nine Mountainous Eastern United States Watersheds: Seasonal Variation and Forest Cutting

EPA Science Inventory

Many engineers and hydrologists use the curve number method to estimate runoff from ungaged watersheds; however, the method does not explicitly account for the influence of season or forest cutting on runoff. This study of observed rainfall and runoff for small, forested watershe...

Howard University Engineers Success: Interdisciplinary Study Keeps Howard on the Cutting Edge

ERIC Educational Resources Information Center

Chew, Cassie M.

2004-01-01

According to Engineering Workforce Commission annual reports, in 1999 Howard University graduated 108 students, 92 of whom were African American, in its chemical, civil, electrical, and mechanical engineering programs and computer science programs. After two more years of graduating approximately 100 students across programs, in 2002, according to…

Optimum angle-cut of collimator for dense objects in high-energy proton radiography

NASA Astrophysics Data System (ADS)

Xu, Hai-Bo; Zheng, Na

2016-02-01

The use of minus identity lenses with an angle-cut collimator can achieve high contrast images in high-energy proton radiography. This article presents the principles of choosing the angle-cut aperture of the collimator for different energies and objects. Numerical simulation using the Monte Carlo code Geant4 has been implemented to investigate the entire radiography for the French test object. The optimum angle-cut apertures of the collimators are also obtained for different energies. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)

Prototype automated post-MECO ascent I-load Verification Data Table

NASA Technical Reports Server (NTRS)

Lardas, George D.

1990-01-01

A prototype automated processor for quality assurance of Space Shuttle post-Main Engine Cut Off (MECO) ascent initialization parameters (I-loads) is described. The processor incorporates Clips rules adapted from the quality assurance criteria for the post-MECO ascent I-loads. Specifically, the criteria are implemented for nominal and abort targets, as given in the 'I-load Verification Data Table, Part 3, Post-MECO Ascent, Version 2.1, December 1989.' This processor, ivdt, compares a given l-load set with the stated mission design and quality assurance criteria. It determines which I-loads violate the stated criteria, and presents a summary of I-loads that pass or fail the tests.

STS-88 Mission Specialist Nancy J. Currie suits up for TCDT

NASA Technical Reports Server (NTRS)

1998-01-01

STS-88 Mission Specialist Nancy J. Currie suits up in the Operations and Checkout Building, as part of flight crew equipment fit check, prior to her trip to Launch Pad 39A. She is helped by suit tech Drew Billingsley. The crew are at KSC to participate in the Terminal Countdown Demonstration Test (TCDT) which includes mission familiarization activities, emergency egress training, and the simulated main engine cut-off exercise. This is Currie's third space flight. Mission STS-88 is targeted for launch on Dec. 3, 1998. It is the first U.S. flight for the assembly of the International Space Station and will carry the Unity connecting module.

Investigating the Effect of Approach Angle and Nose Radius on Surface Quality of Inconel 718

NASA Astrophysics Data System (ADS)

Kumar, Sunil; Singh, Dilbag; Kalsi, Nirmal S.

2017-11-01

This experimental work presents a surface quality evaluation of a Nickel-Cr-Fe based Inconel 718 superalloy, which has many applications in the aero engine and turbine components. However, during machining, the early wear of tool leads to decrease in surface quality. The coating on cutting tool plays a significant role in increasing the wear resistance and life of the tool. In this work, the aim is to study the surface quality of Inconel 718 with TiAlN-coated carbide tools. Influence of various geometrical parameters (tool nose radius, approach angle) and machining variables (cutting velocity, feed rate) on the quality of machined surface (surface roughness) was determined by using central composite design (CCD) matrix. The mathematical model of the same was developed. Analysis of variance was used to find the significance of the parameters. Results showed that the tool nose radius and feed were the main active factors. The present experiment accomplished that TiAlN-coated carbide inserts result in better surface quality as compared with uncoated carbide inserts.

Changes after partial cutting of a spruce-fir stand in Maine

Treesearch

Arthur C. Hart

1956-01-01

In 1945 a partial-cutting experiment in spruce-fir silviculture was begun by the Penobscot Research Center of the Northeastern Forest Experiment Station. The Eastern Pulp Wood Company of Calais, Maine, made available for the study a tract of forest land, in Dyer Township, Washington County, Maine. This 20.6-acre tract is part of a large area that had been burned over...

Pulsed, Hydraulic Coal-Mining Machine

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr.

1986-01-01

In proposed coal-cutting machine, piston forces water through nozzle, expelling pulsed jet that cuts into coal face. Spring-loaded piston reciprocates at end of travel to refill water chamber. Machine a onecylinder, two-cycle, internal-combustion engine, fueled by gasoline, diesel fuel, or hydrogen. Fuel converted more directly into mechanical energy of water jet.

Williams receives a haircut from Yurchikhin in the SM during Expedition 15

NASA Image and Video Library

2007-06-03

ISS015-E-10596 (3 June 2007) --- Cosmonaut Fyodor N. Yurchikhin, Expedition 15 commander representing Russia's Federal Space Agency, cuts astronaut Sunita L. Williams' hair in the Zvezda Service Module of the International Space Station. Williams, flight engineer, holds a vacuum device fashioned to garner freshly cut hair.

Whitson receives haircut from Korzun in Zvezda

NASA Image and Video Library

2002-10-01

ISS005-E-18072 (October 2002) --- Cosmonaut Valery G. Korzun, Expedition Five mission commander, cuts astronaut Peggy A. Whitson’s hair in the Zvezda Service Module on the International Space Station (ISS). Whitson, flight engineer, holds a vacuum device the crew has fashioned to garner freshly cut hair, which is floating freely.

Tyurin gives Lopez-Alegria a hair cut in Node 1 module

NASA Image and Video Library

2007-02-20

ISS014-E-14031 (20 Feb. 2007) --- Cosmonaut Mikhail Tyurin, Expedition 14 flight engineer representing Russia's Federal Space Agency, trims commander Michael E. Lopez-Alegria's hair in the Unity node of the International Space Station. Tyurin used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Whitson receives haircut from Korzun in Zvezda

NASA Image and Video Library

2002-10-01

ISS005-E-18071 (October 2002) --- Cosmonaut Valery G. Korzun, Expedition Five mission commander, cuts astronaut Peggy A. Whitson’s hair in the Zvezda Service Module on the International Space Station (ISS). Whitson, flight engineer, holds a vacuum device the crew has fashioned to garner freshly cut hair, which is floating freely.

Williams receives a haircut from Yurchikhin in the SM during Expedition 15

NASA Image and Video Library

2007-06-03

ISS015-E-10595 (3 June 2007) --- Cosmonaut Fyodor N. Yurchikhin, Expedition 15 commander representing Russia's Federal Space Agency, cuts astronaut Sunita L. Williams' hair in the Zvezda Service Module of the International Space Station. Williams, flight engineer, holds a vacuum device fashioned to garner freshly cut hair.

Level Recession Of Emissions Release By Motor-And-Tractor Diesel Engines Through The Application Of Water-Fuel Emulsions

NASA Astrophysics Data System (ADS)

Ivanov, A.; Chikishev, E.

2017-01-01

The paper is dedicated to a problem of environmental pollution by emissions of hazardous substances with the exhaust gases of internal combustion engines. It is found that application of water-fuel emulsions yields the best results in diesels where production of a qualitative carburetion is the main problem for the organization of working process. During pilot studies the composition of a water-fuel emulsion with the patent held is developed. The developed composition of a water-fuel emulsion provides its stability within 14-18 months depending on mass content of components in it while stability of emulsions’ analogues makes 8-12 months. The mode of operation of pilot unit is described. Methodology and results of pilot study of operation of diesel engine on a water-fuel emulsion are presented. Cutting time of droplet combustion of a water-fuel emulsion improves combustion efficiency and reduces carbon deposition (varnish) on working surfaces. Partial dismantling of the engine after its operating time during 60 engine hours has shown that there is a removal of a carbon deposition in cylinder-piston group which can be observed visually. It is found that for steady operation of the diesel and ensuring decrease in level of emission of hazardous substances the water-fuel emulsion with water concentration of 18-20% is optimal.

Stennis cuts ribbon on records retention facility

NASA Image and Video Library

2010-08-24

NASA's John C. Stennis Space Center cut the ribbon Aug. 24 on a new, storm-resistant Records Retention Facility that consolidates and protects records storage at the nation's premier rocket engine test facility. This facility will also house history office operations. Participants in the ribbon-cutting included: (l to r) Gay Irby, Center Operations deputy director at Stennis; Linda Cureton, NASA chief information officer; Patrick Scheuermann, Stennis director; Jane Odom, NASA chief archivist; Dinna Cottrell, Stennis chief information officer; and James Cluff, Stennis records manager.

Woodcock utilization of commercial timberlands in the northeast

USGS Publications Warehouse

Nicholson, C.P.; Homer, S.; Owen, R.B.; Dilworth, T.G.

1977-01-01

This paper reports the results of studies in Maine (1975-77) and New Brunswick (1974) on the utilization of commercial timber areas by woodcock (Philohela minor). Openings created by logging operations were utilized for singing grounds and nocturnal roosting habitat. Singing male densities of 3.4 birds/1oo ha on were found on New Brunswick elearcuts, 0.24 birds/IOO ha on northern Maine elearcuts, and 1.8-2.1 birds/IOO ha on central Maine selective cuts. Singing male densities in New Brunswick were greater on cuts smaller than 20 ha than on larger cuts. Compared to abandoned agricultural land and alder thickets, earthworm biomass on timber harvest areas was lower and fewer birds used the cuts as diurnal habitat. Regenerating stands provided low quality diurnal habitat, which appeared to limit woodcock numbers on the study areas. The importance of commercial timber harvest operations to future woodcock populations is discussed.

Hardwood Regeneration After Seed Tree Cutting

Treesearch

Robert L. Johnson; R. M. Krinard

1976-01-01

Seed trees left at two sites did not appear to influence the establishment or development of reproduction . Seed trees were mainly sweetgum and red oaks. Most reproduction was from sprouting of the stumps and roots of cut trees or from advanced seedlings present in the understory at the time of cutting. Eighteen years after cutting, dominant trees of the reproduction...

The New Global Responsibilities of Engineers Create Challenges for Engineering Education

ERIC Educational Resources Information Center

Fuchs, Willi

2012-01-01

Modern societies aim to solve the global challenges of the 21st century with sustainable solutions such as resource efficiency, use of renewable energy sources and recycling. Engineers are called upon to create the cutting edge technological solutions that can help to address these challenges. In developed as well as in developing countries,…

Dentine chips produced by nickel-titanium rotary instruments.

PubMed

Guppy, D R; Curtis, R V; Ford, T R

2000-12-01

This study aimed to compare the cross-sectional shape of two nickel-titanium rotary instruments, namely ProFile and Quantec files, both ISO 25, 0.06 taper, and sought to relate this to the chips produced by cutting dentine. A limited comparison was made with stainless steel engine reamers. First, five files of each type were sectioned transversely at 12 mm, 8 mm and 4 mm from the tip and examined by scanning electron microscopy. The cutting angles were assessed by a direct measurement technique which allowed for the inclination of a cutting edge to the root canal. Second, eight samples of cutting debris were collected from instrumentation by each type of nickel-titanium file and four samples from the engine reamers. The major and minor axis, area and roundness of the dentine chips in each sample were measured using computerized particle analysis. The results demonstrated that all files had a negative cutting angle which varied at the different levels (ProFiles range 69.4 degrees to 58.4 degrees and Quantec range 74.8 degrees to 56.8 degrees). The consistency within files of the same type was good as demonstrated by low standard deviations, except for Quantec files at the 4 mm level where higher standard deviations of 4.1 degrees and 5.5 degrees for the two blades were found. The chip analysis showed significant differences between chips produced by ProFile and Quantec files (P < 0.05). The latter were larger and rounder. The chips from the ProFile and the engine reamer chips were similar in dimension (P > 0.05). No simple relationship existed between file geometry and the dentine chips produced during instrumentation.

The Determination of Several Spray Characteristics of a High-Speed Oil Engine Injection System with an Oscilloscope

NASA Technical Reports Server (NTRS)

Hicks, Chester W; Moore, Charles S

1928-01-01

An investigation was conducted to determine the injection lag, duration of injection, and spray start and cut-off characteristics of a fuel injection system operated on an engine and injecting fuel into the atmosphere.

Haircut day

NASA Image and Video Library

2013-07-04

ISS036-E-014568 (4 July 2013) --- Russian cosmonaut Fyodor Yurchikhin, Expedition 36 flight engineer, trims the hair of Russian cosmonaut Alexander Misurkin, flight engineer, in the Unity node of the International Space Station. Yurchikhin used hair clippers fashioned with a vacuum device to garner freshly cut hair.

New Design Heaters Using Tubes Finned by Deforming Cutting Method

NASA Astrophysics Data System (ADS)

Zubkov, N. N.; Nikitenko, S. M.; Nikitenko, M. S.

2017-10-01

The article describes the results of research aimed at selecting and assigning technological processing parameters for obtaining outer fins of heat-exchange tubes by the deformational cutting method, for use in a new design of industrial water-air heaters. The thermohydraulic results of comparative engineering tests of new and standard design air-heaters are presented.

Evolution of Nickel-titanium Alloys in Endodontics.

PubMed

Ounsi, Hani F; Nassif, Wadih; Grandini, Simone; Salameh, Ziad; Neelakantan, Prasanna; Anil, Sukumaran

2017-11-01

To improve clinical use of nickel-titanium (NiTi) endodontic rotary instruments by better understanding the alloys that compose them. A large number of engine-driven NiTi shaping instruments already exists on the market and newer generations are being introduced regularly. While emphasis is being put on design and technique, manufacturers are more discreet about alloy characteristics that dictate instrument behavior. Along with design and technique, alloy characteristics of endodontic instruments is one of the main variables affecting clinical performance. Modification in NiTi alloys is numerous and may yield improvements, but also drawbacks. Martensitic instruments seem to display better cyclic fatigue properties at the expense of surface hardness, prompting the need for surface treatments. On the contrary, such surface treatments may improve cutting efficiency but are detrimental to the gain in cyclic fatigue resistance. Although the design of the instrument is vital, it should in no way cloud the importance of the properties of the alloy and how they influence the clinical behavior of NiTi instruments. Dentists are mostly clinicians rather than engineers. With the advances in instrumentation design and alloys, they have an obligation to deal more intimately with engineering consideration to not only take advantage of their possibilities but also acknowledge their limitations.

Cutting performance orthogonal test of single plane puncture biopsy needle based on puncture force

NASA Astrophysics Data System (ADS)

Xu, Yingqiang; Zhang, Qinhe; Liu, Guowei

2017-04-01

Needle biopsy is a method to extract the cells from the patient's body with a needle for tissue pathological examination. Many factors affect the cutting process of soft tissue, including the geometry of the biopsy needle, the mechanical properties of the soft tissue, the parameters of the puncture process and the interaction between them. This paper conducted orthogonal experiment of main cutting parameters based on single plane puncture biopsy needle, and obtained the cutting force curve of single plane puncture biopsy needle by studying the influence of the inclination angle, diameter and velocity of the single plane puncture biopsy needle on the puncture force of the biopsy needle. Stage analysis of the cutting process of biopsy needle puncture was made to determine the main influencing factors of puncture force during the cutting process, which provides a certain theoretical support for the design of new type of puncture biopsy needle and the operation of puncture biopsy.

Highly Productive Tools For Turning And Milling

NASA Astrophysics Data System (ADS)

Vasilko, Karol

2015-12-01

Beside cutting speed, shift is another important parameter of machining. Its considerable influence is shown mainly in the workpiece machined surface microgeometry. In practice, mainly its combination with the radius of cutting tool tip rounding is used. Options to further increase machining productivity and machined surface quality are hidden in this approach. The paper presents variations of the design of productive cutting tools for lathe work and milling on the base of the use of the laws of the relationship among the highest reached uneveness of machined surface, tool tip radius and shift.

Composite load spectra for select space propulsion structural components

NASA Technical Reports Server (NTRS)

Newell, J. F.; Ho, H. W.; Kurth, R. E.

1991-01-01

The work performed to develop composite load spectra (CLS) for the Space Shuttle Main Engine (SSME) using probabilistic methods. The three methods were implemented to be the engine system influence model. RASCAL was chosen to be the principal method as most component load models were implemented with the method. Validation of RASCAL was performed. High accuracy comparable to the Monte Carlo method can be obtained if a large enough bin size is used. Generic probabilistic models were developed and implemented for load calculations using the probabilistic methods discussed above. Each engine mission, either a real fighter or a test, has three mission phases: the engine start transient phase, the steady state phase, and the engine cut off transient phase. Power level and engine operating inlet conditions change during a mission. The load calculation module provides the steady-state and quasi-steady state calculation procedures with duty-cycle-data option. The quasi-steady state procedure is for engine transient phase calculations. In addition, a few generic probabilistic load models were also developed for specific conditions. These include the fixed transient spike model, the poison arrival transient spike model, and the rare event model. These generic probabilistic load models provide sufficient latitude for simulating loads with specific conditions. For SSME components, turbine blades, transfer ducts, LOX post, and the high pressure oxidizer turbopump (HPOTP) discharge duct were selected for application of the CLS program. They include static pressure loads and dynamic pressure loads for all four components, centrifugal force for the turbine blade, temperatures of thermal loads for all four components, and structural vibration loads for the ducts and LOX posts.

Automated Propulsion Data Screening demonstration system

NASA Technical Reports Server (NTRS)

Hoyt, W. Andes; Choate, Timothy D.; Whitehead, Bruce A.

1995-01-01

A fully-instrumented firing of a propulsion system typically generates a very large quantity of data. In the case of the Space Shuttle Main Engine (SSME), data analysis from ground tests and flights is currently a labor-intensive process. Human experts spend a great deal of time examining the large volume of sensor data generated by each engine firing. These experts look for any anomalies in the data which might indicate engine conditions warranting further investigation. The contract effort was to develop a 'first-cut' screening system for application to SSME engine firings that would identify the relatively small volume of data which is unusual or anomalous in some way. With such a system, limited and expensive human resources could focus on this small volume of unusual data for thorough analysis. The overall project objective was to develop a fully operational Automated Propulsion Data Screening (APDS) system with the capability of detecting significant trends and anomalies in transient and steady-state data. However, the effort limited screening of transient data to ground test data for throttle-down cases typical of the 3-g acceleration, and for engine throttling required to reach the maximum dynamic pressure limits imposed on the Space Shuttle. This APDS is based on neural networks designed to detect anomalies in propulsion system data that are not part of the data used for neural network training. The delivered system allows engineers to build their own screening sets for application to completed or planned firings of the SSME. ERC developers also built some generic screening sets that NASA engineers could apply immediately to their data analysis efforts.

Feasibility Study on Cutting HTPB Propellants with Abrasive Water Jet

NASA Astrophysics Data System (ADS)

Jiang, Dayong; Bai, Yun

2018-01-01

Abrasive water jet is used to carry out the experiment research on cutting HTPB propellants with three components, which will provide technical support for the engineering treatment of waste rocket motor. Based on the reliability theory and related scientific research results, the safety and efficiency of cutting sensitive HTPB propellants by abrasive water jet were experimentally studied. The results show that the safety reliability is not less than 99.52% at 90% confidence level, so the safety is adequately ensured. The cooling and anti-friction effect of high-speed water jet is the decisive factor to suppress the detonation of HTPB propellant. Compared with pure water jet, cutting efficiency was increased by 5% - 87%. The study shows that abrasive water jets meet the practical use for cutting HTPB propellants.

KSC-97PC1613

NASA Image and Video Library

1997-11-05

STS-87 Payload Specialist Leonid Kadenyuk, at right, of the National Space Agency of Ukraine (NSAU) is assisted into his orange launch and entry spacesuit ensemble by NASA Suit Technician Al Rochford, at left, before participating in Terminal Countdown Demonstration Test (TCDT) activities. The crew of the STS-87 mission is scheduled for launch Nov. 19 aboard the Space Shuttle Columbia. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay

STS-87 Commander Kregel holds the crew patch in front of Columbia's entry hatch at LC 39B during TCD

NASA Technical Reports Server (NTRS)

1997-01-01

STS-87 Commander Kevin Kregel holds the crew patch in front of Columbia's entry hatch at Launch Pad 39B during Terminal Countdown Demonstration Test (TCDT) activities. The crew of the STS-87 mission is scheduled for launch Nov. 19 aboard the Space Shuttle Columbia. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

iss038e054117

NASA Image and Video Library

2014-02-22

ISS038-E-054117 (22 Feb. 2014) --- Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, trims the hair of NASA astronaut Rick Mastracchio, flight engineer, in the Unity node of the International Space Station. Wakata used hair clippers fashioned with a vacuum device to garner freshly cut hair.

iss038e054116

NASA Image and Video Library

2014-02-22

ISS038-E-054116 (22 Feb. 2014) --- Japan Aerospace Exploration Agency astronaut Koichi Wakata, Expedition 38 flight engineer, trims the hair of NASA astronaut Rick Mastracchio, flight engineer, in the Unity node of the International Space Station. Wakata used hair clippers fashioned with a vacuum device to garner freshly cut hair.

The Development of STEAM Educational Policy to Promote Student Creativity and Social Empowerment

ERIC Educational Resources Information Center

Allina, Babette

2018-01-01

The Science, Technology, Engineering, Arts, and Mathematics (STEAM) movement argues that broad-based education that promotes creativity recognizes student learning diversity, increases student engagement and can potentially enhance Science, Technology, Engineering, and Mathematics (STEM) learning by embracing cross-cutting translational skills…

Use of Concurrent Engineering in Space Mission Design

NASA Technical Reports Server (NTRS)

Wall, S.

2000-01-01

In recent years, conceptual-phase (proposal level) design of space missions has been improved considerably. Team structures, tool linkage, specialized facilities known as design centers and scripted processes have been demonstrated to cut proposal-level engineering design time from a few months to a few weeks.

A Study on The Development of Local Exhaust Ventilation System (LEV’s) for Installation of Laser Cutting Machine

NASA Astrophysics Data System (ADS)

Harun, S. I.; Idris, S. R. A.; Tamar Jaya, N.

2017-09-01

Local exhaust ventilation (LEV) is an engineering system frequently used in the workplace to protect operators from hazardous substances. The objective of this project is design and fabricate the ventilation system as installation for chamber room of laser cutting machine and to stimulate the air flow inside chamber room of laser cutting machine with the ventilation system that designed. LEV’s fabricated with rated voltage D.C 10.8V and 1.5 ampere. Its capacity 600 ml, continuously use limit approximately 12-15 minute, overall length LEV’s fabricated is 966 mm with net weight 0.88 kg and maximum airflow is 1.3 meter cubic per minute. Stimulate the air flow inside chamber room of laser cutting machine with the ventilation system that designed and fabricated overall result get 2 main gas vapor which air and carbon dioxide. For air gas which experimented by using anemometer, general duct velocity that produce is same with other gas produce, carbon dioxide which 5 m/s until 10 m/s. Overall result for 5 m/s and 10 m/s as minimum and maximum duct velocity produce for both air and carbon dioxide. The air gas flow velocity that captured by LEV’s fabricated, 3.998 m/s average velocity captured from 5 m/s duct velocity which it efficiency of 79.960% and 7.667 m/s average velocity captured from 10 m/s duct velocity with efficiency of 76.665%. For carbon dioxide gas flow velocity that captured by LEV’s fabricated, 3.674 m/s average velocity captured from 5 m/s duct velocity which it efficiency of 73.480% and 8.255 m/s average velocity captured from 10 m/s duct velocity with efficiency of 82.545%.

Curve numbers for nine mountainous eastern United States watersheds: seasonal variation and forest cutting

Treesearch

Negussie H. Tedela; Steven C. McCutcheon; John L. Campbell; Wayne T. Swank; Mary Beth Adams; Todd C. Rasmussen

2012-01-01

Many engineers and hydrologists use the curve number method to estimate runoff from ungaged watersheds; however, the method does not explicitly account for the influence of season or forest cutting on runoff. This study of observed rainfall and runoff for small, forested watersheds that span the Appalachian Mountains of the eastern United States showed that curve...

Tool post modification allows easy turret lathe cutting-tool alignment

NASA Technical Reports Server (NTRS)

Fouts, L.

1966-01-01

Modified tool holder and tool post permit alignment of turret lathe cutting tools on the center of the spindle. The tool is aligned with the spindle by the holder which is kept in position by a hydraulic lock in feature of the tool post. The tool post is used on horizontal and vertical turret lathes and other engine lathes.

78 FR 77789 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-24

... Subdivision, from Control Point (CP) Y901 and Kedzie may be made in accordance with signal indication and at... and from the CP Y901 with the ATC cut out and back-up moves; or, With the ATC cut out due to failure. 2. Operations on the Chicago Service Unit, Geneva Subdivision, from Kedzie and Park CP Y015, engines...

Streamlining Simulation Development using a Commercial Game Engine

DTIC Science & Technology

2009-10-01

few years. The realism is stunning and the Commercial Game Industry fuels the fire of cutting edge advances in hardware and immersive experiences...Technology applies to Military training in more than just the obvious upgrades in game engines and hardware. The increased visual realism and performance...elaborate storytelling and cinematic effects provide a more immersive and compelling experience to the player. The underlying game engine technology

Rock Cutting Depth Model Based on Kinetic Energy of Abrasive Waterjet

NASA Astrophysics Data System (ADS)

Oh, Tae-Min; Cho, Gye-Chun

2016-03-01

Abrasive waterjets are widely used in the fields of civil and mechanical engineering for cutting a great variety of hard materials including rocks, metals, and other materials. Cutting depth is an important index to estimate operating time and cost, but it is very difficult to predict because there are a number of influential variables (e.g., energy, geometry, material, and nozzle system parameters). In this study, the cutting depth is correlated to the maximum kinetic energy expressed in terms of energy (i.e., water pressure, water flow rate, abrasive feed rate, and traverse speed), geometry (i.e., standoff distance), material (i.e., α and β), and nozzle system parameters (i.e., nozzle size, shape, and jet diffusion level). The maximum kinetic energy cutting depth model is verified with experimental test data that are obtained using one type of hard granite specimen for various parameters. The results show a unique curve for a specific rock type in a power function between cutting depth and maximum kinetic energy. The cutting depth model developed here can be very useful for estimating the process time when cutting rock using an abrasive waterjet.

Assessment of Attack Reconnaissance Helicopter (ARH) Machining, Cutting and Drilling Operations

DTIC Science & Technology

2006-09-29

Date: June 20, 2006 Name Organization Email Jim Corwin Consultant JCAI/Army corwinj@att.net Cindy Fenny Process Engineer Bell / Process Engineering...bellhelicopter.textron.com Cindy Fenny Process Eng 817-280-2549 cfenny@bellhelicopter.textron.com Max Trull Process Eng 817-280-2678 mtrull@bellhelicopter.textron.com Ron

Alternative Pulse Detonation Engine Ignition System Investigation through Detonation Splitting

DTIC Science & Technology

2002-03-01

on the soccer field and later discovered is a brilliant and dedicated scientist and engineer. He’s been an inspiration and role model, who sees...designing configurations before cutting metal for an experiment reduces research time and cost. Dr. Vish Katta had built an in-house program ( UNICORN

Building on the foundation for an engineering career

NASA Technical Reports Server (NTRS)

White, Susan; White, Ruth

1994-01-01

A predictable and preventable hurdle stops a majority of young women from entering the scientific and technical fields. This cuts down the individual's career possibilities and cuts in half the pool of potential U.S. engineers later available to industry. The waste of talent does not advance our country's competitive position. The typical American adolescent girl has acquired all the basic mathematical skills needed to pursue science and math, but, from adolescence on, she does not build the foundation of science and math courses that she would need later in life to work in engineering. Several questions are addressed: Why are some young women stopped cold in their mathematical tracks during adolescence? What is the influence of psychology, including discussion of the personality traits quantifiably shared by women in technical fields? and How should the school system adapt to keep their female charges learning math and science?

Evaluation of Separation Mechanism Design for the Orion/Ares Launch Vehicle

NASA Technical Reports Server (NTRS)

Konno, Kevin E.; Catalano, Daniel A.; Krivanek, Thomas M.

2008-01-01

As a part of the preliminary design work being performed for the Orion vehicle, the Orion to Spacecraft Adaptor (SA) separation mechanism was analyzed and sized, with findings presented here. Sizing is based on worst case abort condition as a result of an anomaly driving the launch vehicle engine thrust vector control hard-over causing a severe vehicle pitch over. This worst case scenario occurs just before Upper Stage Main Engine Cut-Off (MECO) when the vehicle is the lightest and the damping effect due to propellant slosh has been reduced to a minimum. To address this scenario and others, two modeling approaches were invoked. The first approach was a detailed 2-D (Simulink) model to quickly assess the Service Module Engine nozzle to SA clearance for a given separation mechanism. The second approach involved the generation of an Automatic Dynamic Analysis of Mechanical Systems (ADAMS) model to assess secondary effects due to mass centers of gravity that were slightly off the vehicle centerline. It also captured any interference between the Solar Arrays and the Spacecraft Adapter. A comparison of modeling results and accuracy are discussed. Most notably, incorporating a larger SA flange diameter allowed for a natural separation of the Orion and its engine nozzle even at relatively large pitch rates minimizing the kickoff force. Advantages and disadvantages of the 2-D model vs. a full 3-D (ADAMS) model are discussed as well.

Evaluation of Separation Mechanism Design for the Orion/Ares Launch Vehicle

NASA Technical Reports Server (NTRS)

Konno, Kevin E.; Catalano, Daniel A.; Krivanek, Thomas M.

2008-01-01

As a part of the preliminary design work being performed for the Orion vehicle, the Orion to Spacecraft Adaptor (SA) separation mechanism mechanism was analyzed and sized, with findings presented here. Sizing is based on worst case abort condition as a result of an anomaly driving the launch vehicle engine thrust vector control hard-over causing a severe vehicle pitch over. This worst case scenario occurs just before Upper Stage Main Engine Cut-Off (MECO) when the vehicle is the lightest and the damping effect due to propellant slosh has been reduced to a minimum. To address this scenario and others, two modeling approaches were invoked. The first approach was a detailed Simulink model to quickly assess the Service Module Engine nozzle to SA clearance for a given separation mechanism. The second approach involved the generation of an Automatic Dynamic Analysis of Mechanical Systems (ADAMS) model to assess secondary effects due to mass centers of gravity that were slightly off the vehicle centerline. It also captured any interference between the Solar Arrays and the Spacecraft Adapter. A comparison of modeling results and accuracy are discussed. Most notably, incorporating a larger SA flange diameter allowed for a natural separation of the Orion and its engine nozzle even at relatively large pitch rates minimizing the kickoff force. Advantages and disadvantages of the Simulink model vs. a full geometric ADAMS model are discussed as well.

Evaluation of Separation Mechanism Design for the Orion/Ares Launch Vehicle

NASA Technical Reports Server (NTRS)

Konno, Kevin E.; Catalano, Daniel A.; Krivanek, Thomas M.

2008-01-01

As a part of the preliminary design work being performed for the Orion vehicle, the Orion to Spacecraft Adaptor (SA) separation mechanism was analyzed and sized, with findings presented here. Sizing is based on worst case abort condition as a result of an anomaly driving the launch vehicle engine thrust vector control hard-over causing a severe vehicle pitch over. This worst-case scenario occurs just before Upper Stage Main Engine Cut-Off when the vehicle is the lightest and the damping effect due to propellant slosh has been reduced to a minimum. To address this scenario and others, two modeling approaches were invoked. The first approach was a detailed Simulink model to quickly assess the Service Module Engine nozzle to SA clearance for a given separation mechanism. The second approach involved the generation of an Automatic Dynamic Analysis of Mechanical Systems (ADAMS) model to assess secondary effects due to mass centers of gravity that were slightly off the vehicle centerline. It also captured any interference between the Solar Arrays and the Spacecraft Adapter. A comparison of modeling results and accuracy are discussed. Most notably, incorporating a larger SA flange diameter allowed for a natural separation of the Orion and its engine nozzle even at relatively large pitch rates minimizing the kickoff force. Advantages and disadvantages of the Simulink model vs. a full geometric ADAMS model are discussed as well.

Evaluation of Separation Mechanism Design for the Orion/Ares Launch Vehicle

NASA Technical Reports Server (NTRS)

Konno, Kevin E.; Catalano, Daniel A.; Krivanek, Thomas M.

2008-01-01

As a part of the preliminary design work being performed for the Orion vehicle, the Orion to Spacecraft Adaptor (SA) separation mechanism was analyzed and sized, with findings presented here. Sizing is based on worst case abort condition as a result of an anomaly driving the launch vehicle engine thrust vector control hard-over causing a severe vehicle pitch over. This worst case scenario occurs just before Upper Stage Main Engine Cut-Off (MECO) when the vehicle is the lightest and the damping effect due to propellant slosh has been reduced to a minimum. To address this scenario and others, two modeling approaches were invoked. The first approach was a detailed Simulink model to quickly assess the Service Module Engine nozzle to SA clearance for a given separation mechanism. The second approach involved the generation of an Automatic Dynamic Analysis of Mechanical Systems (ADAMS) model to assess secondary effects due to mass centers of gravity that were slightly off the vehicle centerline. It also captured any interference between the Solar Arrays and the Spacecraft Adapter. A comparison of modeling results and accuracy are discussed. Most notably, incorporating a larger SA flange diameter allowed for a natural separation of the Orion and it's engine nozzle even at relatively large pitch rates minimizing the kickoff force. Advantages and disadvantages of the Simulink model vs. a full geometric ADAMS model are discussed as well.

An algorithm developed in Matlab for the automatic selection of cut-off frequencies, in the correction of strong motion data

NASA Astrophysics Data System (ADS)

Sakkas, Georgios; Sakellariou, Nikolaos

2018-05-01

Strong motion recordings are the key in many earthquake engineering applications and are also fundamental for seismic design. The present study focuses on the automated correction of accelerograms, analog and digital. The main feature of the proposed algorithm is the automatic selection for the cut-off frequencies based on a minimum spectral value in a predefined frequency bandwidth, instead of the typical signal-to-noise approach. The algorithm follows the basic steps of the correction procedure (instrument correction, baseline correction and appropriate filtering). Besides the corrected time histories, Peak Ground Acceleration, Peak Ground Velocity, Peak Ground Displacement values and the corrected Fourier Spectra are also calculated as well as the response spectra. The algorithm is written in Matlab environment, is fast enough and can be used for batch processing or in real-time applications. In addition, the possibility to also perform a signal-to-noise ratio is added as well as to perform causal or acausal filtering. The algorithm has been tested in six significant earthquakes (Kozani-Grevena 1995, Aigio 1995, Athens 1999, Lefkada 2003 and Kefalonia 2014) of the Greek territory with analog and digital accelerograms.

Leaning and Greening the Supply Chain: A Teaching Case Study for Engineering Students

ERIC Educational Resources Information Center

Grantham, Katie; Cudney, Elizabeth

2011-01-01

A version of the American Clean Energy and Security Act, passed by the House of Representatives in June 2009, mandates a 17% cut in emissions by 2020 and upwards of an 80% cut by 2050, based on emissions from 2005. This impending legislation is a challenge to companies already trying to survive in an economic downturn. It is critical that the…

Production of volatiles in fresh-cut apple: effect of applying alginate coatings containing linoleic acid or isoleucine.

PubMed

Maya-Meraz, Irma O; Espino-Díaz, Miguel; Molina-Corral, Francisco J; González-Aguilar, Gustavo A; Jacobo-Cuellar, Juan L; Sepulveda, David R; Olivas, Guadalupe I

2014-11-01

One of the main quality parameters in apples is aroma, its main precursors are fatty acids (FA) and amino acids (AA). In this study, alginate edible coatings were used as carriers of linoleic acid or isoleucine to serve as precursors for the production of aroma in cut apples. Apple wedges were immersed in a CaCl2 solution and coated with one of the following formulations: alginate solution (Alg-Ca), Alg-Ca-low-level linoleic acid (0.61 g/Lt), (LFA), Alg-Ca-high-level linoleic acid (2.44 g/L; HFA), Alg-Ca-low-level isoleucine (0.61 g/L; LAA), and Alg-Ca-high-level isoleucine (2.44 g/L; HAA). Apple wedges were stored at 3 °C and 85% relative humidity for 21 d and key volatiles were studied during storage. Addition of precursors, mainly isoleucine, showed to increase the production of some key volatiles on coated fresh-cut apples during storage. The concentration of 2-methyl-1-butanol was 4 times higher from day 12 to day 21 in HAA, while 2-methyl butyl acetate increased from day 12 to day 21 in HAA. After 21 d, HAA-apples presented a 40-fold value of 2-methyl-butyl acetate, compared to Alg-Ca cut apples. Values of hexanal increased during cut apple storage when the coating carried linoleic acid, mainly on HFA, from 3 to 12 d. The ability of apples to metabolize AA and FA depends on the concentration of precursors, but also depends on key enzymes, previous apple storage, among others. Further studies should be done to better clarify the behavior of fresh-cut apples as living tissue to metabolize precursors contained in edible coatings for the production of volatiles. © 2014 Institute of Food Technologists®

Murine precision-cut lung slices exhibit acute responses following exposure to gasoline direct injection engine emissions.

PubMed

Maikawa, Caitlin L; Zimmerman, Naomi; Rais, Khaled; Shah, Mittal; Hawley, Brie; Pant, Pallavi; Jeong, Cheol-Heon; Delgado-Saborit, Juana Maria; Volckens, John; Evans, Greg; Wallace, James S; Godri Pollitt, Krystal J

2016-10-15

Gasoline direct injection (GDI) engines are increasingly prevalent in the global vehicle fleet. Particulate matter emissions from GDI engines are elevated compared to conventional gasoline engines. The pulmonary effects of these higher particulate emissions are unclear. This study investigated the pulmonary responses induced by GDI engine exhaust using an ex vivo model. The physiochemical properties of GDI engine exhaust were assessed. Precision cut lung slices were prepared using Balb/c mice to evaluate the pulmonary response induced by one-hour exposure to engine-out exhaust from a laboratory GDI engine operated at conditions equivalent to vehicle highway cruise conditions. Lung slices were exposed at an air-liquid interface using an electrostatic aerosol in vitro exposure system. Particulate and gaseous exhaust was fractionated to contrast mRNA production related to polycyclic aromatic hydrocarbon (PAH) metabolism and oxidative stress. Exposure to GDI engine exhaust upregulated genes involved in PAH metabolism, including Cyp1a1 (2.71, SE=0.22), and Cyp1b1 (3.24, SE=0.12) compared to HEPA filtered air (p<0.05). GDI engine exhaust further increased Cyp1b1 expression compared to filtered GDI engine exhaust (i.e., gas fraction only), suggesting this response was associated with the particulate fraction. Exhaust particulate was dominated by high molecular weight PAHs. Hmox1, an oxidative stress marker, exhibited increased expression after exposure to GDI (1.63, SE=0.03) and filtered GDI (1.55, SE=0.04) engine exhaust compared to HEPA filtered air (p<0.05), likely attributable to a combination of the gas and particulate fractions. Exposure to GDI engine exhaust contributes to upregulation of genes related to the metabolism of PAHs and oxidative stress. Copyright © 2016 Elsevier B.V. All rights reserved.

Modern laser technologies used for cutting textile materials

NASA Astrophysics Data System (ADS)

Isarie, Claudiu; Dragan, Anca; Isarie, Laura; Nastase, Dan

2006-02-01

With modern laser technologies we can cut multiple layers at once, yielding high production levels and short setup times between cutting runs. One example could be the operation of cutting the material named Nylon 66, used to manufacture automobile airbags. With laser, up to seven layers of Nylon 66 can be cut in one pass, that means high production rates on a single machine. Airbags must be precisely crafted piece of critical safety equipment that is built to very high levels of precision in a mass production environment. Of course, synthetic material, used for airbags, can be cut also by a conventional fixed blade system, but for a high production rates and a long term low-maintenance, laser cutting is most suitable. Most systems, are equipped with two material handling systems, which can cut on one half of he table while the finished product is being removed from the other half and the new stock material laid out. The laser system is reliable and adaptable to any flatbed-cutting task. Computer controlled industrial cutting and plotting machines are the latest offerings from a well established and experienced industrial engineering company that is dedicated to reduce cutting costs and boosting productivity in today's competitive industrial machine tool market. In this way, just one machine can carry out a multitude of production tasks. Authors have studied the cutting parameters for different textile materials, to reach the maximum output of the process.

Mechanical pre-cutting, a rediscovered tunneling technique

NASA Astrophysics Data System (ADS)

van Walsum, E.

1991-04-01

In 1950, the exact outlines of some circular tunnels, to be driven through chalk for the Corps of Engineers' Fort Randall Reservoir Project on the Missouri River at Pickstown, South Dakota, U.S.A., were pre-cut mechanically, i. e. prior to blasting the tunnel openings. No further applications of mechanical pre-cutting as a tunneling technique were made until the technique was rediscovered and further developed in France during the seventies. These further developments relate to the pre-cutting of harder rocks and the pre-cutting of cohesive and non-cohesive soils combined with the construction of a concrete pre-lining, i. e. a lining which is in place before the ground under it is excavated. Mechanical pre-cutting, as presently practiced, improves the quality and safety of tunneling and reduces surface settlement, noise and vibration. It is concluded that the technique is likely to be applied in the future in the construction of various types of underground structures whenever conventional tunneling is too risky or when environmental concerns are important.

Monitoring micro-crack healing in an engineered cementitious composite using the environmental scanning electron microscope

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

Suryanto, B., E-mail: b.suryanto@hw.ac.uk; Buckman

Environmental Scanning Electron Microscopy (ESEM) is used to study the origin of micro-crack healing in an Engineered Cementitious Composite (ECC). ESEM images were acquired from ECC specimens cut from pre-cracked, dog-bone samples which then subjected to submerged curing followed by exposure to the natural environment. The mineralogical and chemical compositions of the healing products were determined using the EDX facility in the ESEM. It is shown that the precipitation of calcium carbonate is the main contributor to micro-crack healing at the crack mouth. The healing products initially appeared in an angular rhombohedral morphology which then underwent a discernable transformation inmore » size, shape and surface texture, from relatively flat and smooth to irregular and rough, resembling the texture of the original surface areas surrounding the micro-cracks. It is also shown that exposure to the natural environment, involving intermittent wetting/drying cycles, promotes additional crystal growth, which indicates enhanced self-healing capability in this environment. - Highlights: •ESEM with EDX used to characterize the origin of micro-crack healing in an ECC •Evolution of healing precipitates studied at three specific locations over four weeks •Specimens exposed to laboratory environment, followed by the natural environment •Calcium carbonate is the main contributor to crack healing at the crack mouth. •Outdoor exposure involving intermittent rain promotes additional crystal growth.« less

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

Yuuichi Tooya; Tadahiro Washiya; Kenji Koizumi

Japan Atomic Energy Agency (JAEA) has been leading feasibility study on commercialized fast reactor cycle systems in Japan. In this study, we have proposed a new disassembly technology by mechanical disassembly system that consists of a mechanical cutting step and a wrapper tube pulling step. In the mechanical disassembly system, high durability mechanical tool grinds the wrapper tube (Slit-cut (S/C) operation in circle direction), and then the wrapper tube is pulled out and removed from the fuel assembly. Then the fuel pins are cut (Crop-cut (C/C) operation at entrance nozzle side) and the entrance nozzle is removed. The fuel pinsmore » are transported to the shearing device in next process. The Fundamental tests were carried out with simulated FBR fuel pins and wrapper tube, and cutting performance and wrapper tube pulling performance has been confirmed by engineering scale. As results, we established an efficient disassembly procedure and the fundamental design of mechanical disassembly system. (authors)« less

STS-87 Mission Specialist Chawla is assisted with her launch and entry spacesuit at LC 39B during TC

NASA Technical Reports Server (NTRS)

1997-01-01

STS-87 Mission Specialist Kalpana Chawla, Ph.D., is assisted with her orange launch and entry spacesuit by NASA suit technicians at Launch Pad 39B during Terminal Countdown Demonstration Test (TCDT) activities. The crew of the STS-87 mission is scheduled for launch Nov. 19 aboard the Space Shuttle Columbia. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

Report on the Conference on Transposition and Genome Engineering 2015 (TGE 2015): advancing cutting-edge genomics technology in the ancient city of Nara.

PubMed

Woltjen, Knut; Yamamoto, Takashi; Kokubu, Chikara; Takeda, Junji

2016-05-01

From November 17 to 20 in 2015, the Conference on Transposition and Genome Engineering 2015 (TGE 2015) was held at Nara Kasugano International Forum-IRAKA-in Nara, Japan, located at the center of Nara Park. All of the presentations were carried out at Nohgaku hall in Nara Kasugano International Forum-IRAKA. Participation totaled 148 persons (30 international, 118 domestic), who were able to engage in lively scientific discussions over the 4-day period. The guest speaker list consisted of many top-notch international researchers, an achievement for which the conference received praise from the attendees. There were 36 oral presentations including the keynote lecture (22 presentations from guest speakers, complemented with 14 selected from abstract submissions). Additionally, there were 46 poster presentations. The conference uniquely combined research mainly from two different genomics approaches: (i) transposon technology allowing random genomic integration followed by gene discovery-related phenotypes and (ii) genome editing technology with designer nuclease allowing precise modification of a gene-of-interest. © 2016 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Tyurin gives Culbertson a haircut in the Service Module during Expedition Three

NASA Image and Video Library

2001-09-22

ISS003-E-5901 (22 September 2001) --- Astronaut Frank L. Culbertson, Jr. (right), Expedition Three mission commander, holds a vacuum device the crew has fashioned to garner freshly cut hair floating freely, as Mikhail Tyurin cuts his hair in the Zvezda Service Module on the International Space Station (ISS). Tyurin is a flight engineer representing Rosaviakosmos. This image was taken with a digital still camera.

Tyurin gives Dezhurov a haircut in the Service Module during Expedition Three

NASA Image and Video Library

2001-09-22

ISS003-E-5891 (22 September 2001) --- Cosmonauts Mikhail Tyurin (left) and Vladimir N. Dezhurov, Expedition Three flight engineers representing Rosaviakosmos, take turns cutting each other’s hair in the Zvezda Service Module on the International Space Station (ISS). Dezhurov holds a vacuum device the crew has fashioned to garner freshly cut hair floating freely. This image was taken with a digital still camera.

Tyurin gives Culbertson a haircut in the Service Module during Expedition Three

NASA Image and Video Library

2001-09-22

ISS003-E-5896 (22 September 2001) --- Astronaut Frank L. Culbertson, Jr. (right), Expedition Three mission commander, holds a vacuum device the crew has fashioned to garner freshly cut hair floating freely, as Mikhail Tyurin cuts his hair in the Zvezda Service Module on the International Space Station (ISS). Tyurin is a flight engineer representing Rosaviakosmos. This image was taken with a digital still camera.

The Evolution of Utilizing Manual Throttles to Avoid Excessively Low LH2 NPSP at the SSME Inlet

NASA Technical Reports Server (NTRS)

Henfling, Rick

2011-01-01

In the late 1970s, years before the Space Shuttle flew its maiden voyage, it was understood low liquid hydrogen (LH2) Net Positive Suction Pressure (NPSP) at the inlet to the Space Shuttle Main Engine (SSME) could have adverse effects on engine operation. A number of failures within both the External Tank (ET) and the Orbiter Main Propulsion System (MPS) could result in a low LH2 NPSP condition, which at extremely low levels can result in cavitation of SSME turbomachinery. Operational workarounds were developed to take advantage of the onboard crew s ability to manually throttle down the SSMEs (via the Pilot s Speedbrake/Throttle Controller), which alleviated the low LH2 NPSP condition. Manually throttling the SSME to a lower power level resulted in an increase in NPSP, mainly due to the reduction in frictional flow losses while at the lower throttle setting. Early in the Space Shuttle Program s history, the relevant Flight Rule for the Booster flight controllers in Mission Control did not distinguish between ET and Orbiter MPS failures and the same crew action was taken for both. However, after a review of all Booster operational techniques following the Challenger disaster in the late 1980s, it was determined manually throttling the SSME to a lower power was only effective for Orbiter MPS failures and the Flight Rule was updated to reflect this change. The Flight Rule and associated crew actions initially called for a single throttle step to minimum power level when a low threshold for NPSP was met. As engineers refined their understanding of the NPSP requirements for the SSME (through a robust testing program), the operational techniques evolved to take advantage of the additional capabilities. This paper will examine the evolution of the Flight rule and associated procedure and how increases in knowledge about the SSME and the Space Shuttle vehicle as a whole have helped shape their development. What once was a single throttle step when NPSP decreased to a certain threshold has now become three throttle steps, each occurring at a lower NPSP threshold. Additionally the procedure, which for early Space Shuttle missions required a Return-to-Launch-Site abort, now results in a nominal Main Engine Cut Off and no loss of mission objectives.

The Evolution of Utilizing Manual Throttling to Avoid Excessively Low LH2 NPSP at the SSME Inlet

NASA Technical Reports Server (NTRS)

Henfling, Rick

2010-01-01

In the late 1970s, years before the Space Shuttle flew its maiden voyage, it was understood low liquid hydrogen (LH2) Net Positive Suction Pressure (NPSP) at the inlet to the Space Shuttle Main Engine (SSME) could have adverse effects on engine operation. A number of failures within both the External Tank (ET) and the Orbiter Main Propulsion System (MPS) could result in a low LH2 NPSP condition, which at extremely low levels can result in cavitation of SSME turbomachinery. Operational workarounds were developed to take advantage of the onboard crew s ability to manually throttle down the SSMEs (via the Pilot s Speedbrake/Throttle Controller), which alleviated the low LH2 NPSP condition. Manually throttling the SSME to a lower power level resulted in an increase in NPSP, mainly due to the reduction in frictional flow losses while at the lower throttle setting. Early in the Space Shuttle Program s history, the relevant Flight Rule for the Booster flight controller in Mission Control did not distinguish between ET and Orbiter MPS failures and the same crew action was taken for both. However, after a review of all Booster operational techniques following the Challenger disaster in the late 1980s, it was determined manually throttling the SSME to a lower power was only effective for Orbiter MPS failures and the Flight Rule was updated to reflect this change. The Flight Rule and associated crew actions initially called for a single throttle step to minimum power level when a low threshold for NPSP was met. As engineers refined their understanding of the NPSP requirements for the SSME (through a robust testing program), the operational techniques evolved to take advantage of the additional capabilities. This paper will examine the evolution of the Flight rule and associated procedure and how increases in knowledge about the SSME and the Space Shuttle vehicle as a whole have helped shape their development. What once was a single throttle step when NPSP decreased to a certain low threshold has now become three throttle steps, each occurring at a lower NPSP threshold. Additionally the procedure, which for early Space Shuttle missions required a Return-to-Launch-Site abort, now results in a nominal Main Engine Cut Off and no loss of mission objectives.

Optimization of Interior Permanent Magnet Motor by Quality Engineering and Multivariate Analysis

NASA Astrophysics Data System (ADS)

Okada, Yukihiro; Kawase, Yoshihiro

This paper has described the method of optimization based on the finite element method. The quality engineering and the multivariable analysis are used as the optimization technique. This optimizing method consists of two steps. At Step.1, the influence of parameters for output is obtained quantitatively, at Step.2, the number of calculation by the FEM can be cut down. That is, the optimal combination of the design parameters, which satisfies the required characteristic, can be searched for efficiently. In addition, this method is applied to a design of IPM motor to reduce the torque ripple. The final shape can maintain average torque and cut down the torque ripple 65%. Furthermore, the amount of permanent magnets can be reduced.

Methods and Research for Multi-Component Cutting Force Sensing Devices and Approaches in Machining

PubMed Central

Liang, Qiaokang; Zhang, Dan; Wu, Wanneng; Zou, Kunlin

2016-01-01

Multi-component cutting force sensing systems in manufacturing processes applied to cutting tools are gradually becoming the most significant monitoring indicator. Their signals have been extensively applied to evaluate the machinability of workpiece materials, predict cutter breakage, estimate cutting tool wear, control machine tool chatter, determine stable machining parameters, and improve surface finish. Robust and effective sensing systems with capability of monitoring the cutting force in machine operations in real time are crucial for realizing the full potential of cutting capabilities of computer numerically controlled (CNC) tools. The main objective of this paper is to present a brief review of the existing achievements in the field of multi-component cutting force sensing systems in modern manufacturing. PMID:27854322

Methods and Research for Multi-Component Cutting Force Sensing Devices and Approaches in Machining.

PubMed

Liang, Qiaokang; Zhang, Dan; Wu, Wanneng; Zou, Kunlin

2016-11-16

Multi-component cutting force sensing systems in manufacturing processes applied to cutting tools are gradually becoming the most significant monitoring indicator. Their signals have been extensively applied to evaluate the machinability of workpiece materials, predict cutter breakage, estimate cutting tool wear, control machine tool chatter, determine stable machining parameters, and improve surface finish. Robust and effective sensing systems with capability of monitoring the cutting force in machine operations in real time are crucial for realizing the full potential of cutting capabilities of computer numerically controlled (CNC) tools. The main objective of this paper is to present a brief review of the existing achievements in the field of multi-component cutting force sensing systems in modern manufacturing.

Marshall Space Flight Center Materials and Processes Laboratory

NASA Technical Reports Server (NTRS)

Tramel, Terri L.

2012-01-01

Marshall?s Materials and Processes Laboratory has been a core capability for NASA for over fifty years. MSFC has a proven heritage and recognized expertise in materials and manufacturing that are essential to enable and sustain space exploration. Marshall provides a "systems-wise" capability for applied research, flight hardware development, and sustaining engineering. Our history of leadership and achievements in materials, manufacturing, and flight experiments includes Apollo, Skylab, Mir, Spacelab, Shuttle (Space Shuttle Main Engine, External Tank, Reusable Solid Rocket Motor, and Solid Rocket Booster), Hubble, Chandra, and the International Space Station. MSFC?s National Center for Advanced Manufacturing, NCAM, facilitates major M&P advanced manufacturing partnership activities with academia, industry and other local, state and federal government agencies. The Materials and Processes Laborato ry has principal competencies in metals, composites, ceramics, additive manufacturing, materials and process modeling and simulation, space environmental effects, non-destructive evaluation, and fracture and failure analysis provide products ranging from materials research in space to fully integrated solutions for large complex systems challenges. Marshall?s materials research, development and manufacturing capabilities assure that NASA and National missions have access to cutting-edge, cost-effective engineering design and production options that are frugal in using design margins and are verified as safe and reliable. These are all critical factors in both future mission success and affordability.

Rock Drilling Performance Evaluation by an Energy Dissipation Based Rock Brittleness Index

NASA Astrophysics Data System (ADS)

Munoz, H.; Taheri, A.; Chanda, E. K.

2016-08-01

To reliably estimate drilling performance both tool-rock interaction laws along with a proper rock brittleness index are required to be implemented. In this study, the performance of a single polycrystalline diamond compact (PDC) cutter cutting and different drilling methods including PDC rotary drilling, roller-cone rotary drilling and percussive drilling were investigated. To investigate drilling performance by rock strength properties, laboratory PDC cutting tests were performed on different rocks to obtain cutting parameters. In addition, results of laboratory and field drilling on different rocks found elsewhere in literature were used. Laboratory and field cutting and drilling test results were coupled with values of a new rock brittleness index proposed herein and developed based on energy dissipation withdrawn from the complete stress-strain curve in uniaxial compression. To quantify cutting and drilling performance, the intrinsic specific energy in rotary-cutting action, i.e. the energy consumed in pure cutting action, and drilling penetration rate values in percussive action were used. The results show that the new energy-based brittleness index successfully describes the performance of different cutting and drilling methods and therefore is relevant to assess drilling performance for engineering applications.

Heritage stones and their deterioration in rock-cut monuments in India

NASA Astrophysics Data System (ADS)

Sharma, Vinod K.

2017-04-01

India is dotted with thousands of rock- cut monuments of considerable antiquity having artwork of global importance. It is evident from the location of many of these monuments that knowledge of viable selection of site, geotechnical considerations and amenability to sculptures' chisel was vital for construction of rock-cut monuments and sculptures. These rock-cut structures also represent significant achievements of geotechnical and structural engineering and craftsmanship of contemporary period. The paper deals with some of the sites where natural rock-mass exposures were used to hew the monuments and highlight the deterioration owing to geological and climatic conditions. The Kailash temple in Ellora and Ajanta rock-cut caves are among the greatest architectural feats which owe their grandeur to amenability and consistency of basalt of Deccan Volcanic Province from which it is hewn. The Kailash Temple was created through a single, huge top-down excavation 100 feet deep down into the volcanic basaltic cliff rock. These ancient rock cut structures are amazing achievements of structural engineering and craftsmanship. The lava flows are nearly horizontal, competent rock medium facilitated the chiseling for the sculptures. The deterioration of these basalts are seen where the amygdule, vesicles and opening in rock discontinuity had the medium of construction or excavation. The monolithic rock- cut monuments of Mahabalipuram temples are constructed in the form of rathas or chriot and adjoining caves by excavating solid charnockite/granites. The large rock exposures are excavated and cut to perfection with wall decorations and sculptured art. The charnockites are the strongest and the most durable rock, yet quite amenable to fine dressing. These monolithic monuments in charnockite and are cut out of the hillock. The 7th Century monuments now exhibit somewhat rough surface probably due to weathering effect of salt laden winds from the sea side and alteration of feldspars. The Rock shelters of Bhimbetka, a World Heritage Site, are located within Vindhyan sandstone, yielded primitive tools and decorative rock paintings.The rock-cut caves in twin hills Udayagiri and Khandagiri , contain carvings sculptured in coarse grained grey to buff coloured sandstone of Gondwana group of rocks. The Badami cave temples constructed out of escarpment of the hill in sandstone represent some of the earliest known examples of Hindu temples. Utilizing in situ rock exposures, natural rocks and landscape of Deccan basalts, granites of peninsular shield, sandstones and limestone for rock cut architecture in India, thus, holds varied examples of rock-cut architectures.

Comparison of Fixed Diameter-Limit and Selection Cutting in Northern Conifers

Treesearch

Laura S. Kenefic; Paul E. Sendak; John C. Brissette

2005-01-01

Diameter-limit cutting is a common type of harvest in which all merchantable trees above specific size thresholds are removed. Despite a long history of application, controlled experiments of these harvests are rare and the cumulative effects of repeated diameter-limit cuts are largely unknown. The Penobscot Experimental Forest in Maine is the location of a long-term...

View of an Expedition 21 Crew Member trimming his hair in the Destiny Laboratory

NASA Image and Video Library

2009-10-11

ISS021-E-005067 (11 Oct. 2009) --- Russian cosmonaut Maxim Suraev, Expedition 21 flight engineer, trims his hair in the Destiny laboratory of the International Space Station, using hair clippers fashioned with a vacuum device to garner freshly cut hair. Canadian Space Agency astronaut Robert Thirsk, flight engineer, is at right.

Crewmembers in the Node 1/Unity during Expedition 13

NASA Image and Video Library

2006-07-29

ISS013-E-62373 (29 July 2006) --- Astronaut Jeffrey N. Williams, Expedition 13 NASA space station science officer and flight engineer, trims astronaut Thomas Reiter's hair in the Unity node of the International Space Station. Williams used hair clippers fashioned with a vacuum device to garner freshly cut hair. Reiter, flight engineer, represents the European Space Agency (ESA).

An Analysis of Insulated Concrete Forms for use in Sustainable Military Construction

DTIC Science & Technology

2014-03-27

CONSTRUCTION THESIS Presented to the Faculty Department of Systems and Engineering Management Graduate School of Engineering and Management...which fit together and are filled with reinforced concrete to construct the exterior wall systems of a building. By design, this material provides a...Forms with Rebar .............................................................. 12 Figure 3. Cut outs of ICF wall systems

A Simplified Model of Human Alcohol Metabolism That Integrates Biotechnology and Human Health into a Mass Balance Team Project

ERIC Educational Resources Information Center

Yang, Allen H. J.; Dimiduk, Kathryn; Daniel, Susan

2011-01-01

We present a simplified human alcohol metabolism model for a mass balance team project. Students explore aspects of engineering in biotechnology: designing/modeling biological systems, testing the design/model, evaluating new conditions, and exploring cutting-edge "lab-on-a-chip" research. This project highlights chemical engineering's impact on…

Research Technology

NASA Image and Video Library

1998-09-16

A team of engineers at Marshall Space Flight Center (MSFC) has designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket that produces lower thrust but has better thrust efficiency than the chemical combustion engines. This segmented array of mirrors is the solar concentrator test stand at MSFC for firing the thermal propulsion engines. The 144 mirrors are combined to form an 18-foot diameter array concentrator. The mirror segments are aluminum hexagons that have the reflective surface cut into it by a diamond turning machine, which is developed by MSFC Space Optics Manufacturing Technology Center.

Details of the Construction and Production of Fuel Pumps and Fuel Nozzles for the Airplane Diesel Engine

NASA Technical Reports Server (NTRS)

Lubenetsky, W S

1936-01-01

This report presents investigations into the design and construction of fuel pumps for diesel engines. The results of the pump tests on the engines showed that, with a good cut-off, accurate injection, assured by the proper adjustment of the pump elements, there is a decrease in the consumption of fuel and hence an increase in the rated power of the engine. Some of the aspects investigated include: cam profile, coefficient of discharge, and characteristics of the injection system.

16. SAME ROOMOAK FRAMES, CUT FROM PATTERNS, ARE READIED FOR ...

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

16. SAME ROOM-OAK FRAMES, CUT FROM PATTERNS, ARE READIED FOR CLAMPING AND GLUING ON WORKBENCH. COMPLETED BOATS CAN BE SEEN ON RIVER OUTSIDE WINDOW. - Lowell's Boat Shop, 459 Main Street, Amesbury, Essex County, MA

Spoke permanent magnet machine with reduced torque ripple and method of manufacturing thereof

DOEpatents

Reddy, Patel Bhageerath; EL-Refaie, Ayman Mohamed Fawzi; Huh, Kum-Kang; Alexander, James Pellegrino

2016-03-15

An internal permanent magnet machine includes a rotor assembly having a shaft comprising a plurality of protrusions extending radially outward from a main shaft body and being formed circumferentially about the main shaft body and along an axial length of the main shaft body. A plurality of stacks of laminations are arranged circumferentially about the shaft to receive the plurality of protrusions therein, with each stack of laminations including a plurality of lamination groups arranged axially along a length of the shaft and with permanent magnets being disposed between the stacks of laminations. Each of the laminations includes a shaft protrusion cut formed therein to receive a respective shaft protrusion and, for each of the stacks of laminations, the shaft protrusion cuts formed in the laminations of a respective lamination group are angularly offset from the shaft protrusion cuts formed in the laminations in an adjacent lamination group.

Pathways and Challenges to Innovation in Aerospace

NASA Technical Reports Server (NTRS)

Terrile, Richard J.

2010-01-01

This paper explores impediments to innovation in aerospace and suggests how successful pathways from other industries can be adopted to facilitate greater innovation. Because of its nature, space exploration would seem to be a ripe field of technical innovation. However, engineering can also be a frustratingly conservative endeavor when the realities of cost and risk are included. Impediments like the "find the fault" engineering culture, the treatment of technical risk as almost always evaluated in terms of negative impact, the difficult to account for expansive Moore's Law growth when making predictions, and the stove-piped structural organization of most large aerospace companies and federally funded research laboratories tend to inhibit cross-cutting technical innovation. One successful example of a multi-use cross cutting application that can scale with Moore's Law is the Evolutionary Computational Methods (ECM) technique developed at the Jet Propulsion Lab for automated spectral retrieval. Future innovations like computational engineering and automated design optimization can potentially redefine space exploration, but will require learning lessons from successful innovators.

Impact of gate engineering in enhancement mode n++GaN/InAlN/AlN/GaN HEMTs

NASA Astrophysics Data System (ADS)

Adak, Sarosij; Swain, Sanjit Kumar; Rahaman, Hafizur; Sarkar, Chandan Kumar

2016-12-01

This paper illustrate the effect of gate material engineering on the performance of enhancement mode n++GaN/InAlN/AlN/GaN high electron mobility transistors (HEMTs). A comparative analysis of key device parameters is discussed for the Triple Material Gate (TMG), Dual Material Gate (DMG) and the Single Material Gate (SMG) structure HEMTs by considering the same device dimensions. The simulation results shows that an significant improvement is noticed in the key analysis parameters such as drain current (Id), transconductance (gm), cut off frequency (fT), RF current gain, maximum cut off frequency (fmax) and RF power gain of the gate material engineered devices with respect to SMG normally off n++GaN/InAlN/AlN/GaN HEMTs. This improvement is due to the existence of the perceivable step in the surface potential along the channel which successfully screens the drain potential variation in the source side of the channel for the gate engineering devices. The analysis suggested that the proposed TMG and DMG engineered structure enhancement mode n++GaN/InAlN/AlN/GaN HEMTs can be considered as a potential device for future high speed, microwave and digital application.

Developmental problems and their solution for the Space Shuttle main engine alternate liquid oxygen high-pressure turbopump: Anomaly or failure investigation the key

NASA Astrophysics Data System (ADS)

Ryan, R.; Gross, L. A.

1995-05-01

The Space Shuttle main engine (SSME) alternate high-pressure liquid oxygen pump experienced synchronous vibration and ball bearing life problems that were program threatening. The success of the program hinged on the ability to solve these development problems. The design and solutions to these problems are engirded in the lessons learned and experiences from prior programs, technology programs, and the ability to properly conduct failure or anomaly investigations. The failure investigation determines the problem cause and is the basis for recommending design solutions. For a complex problem, a comprehensive solution requires that formal investigation procedures be used, including fault trees, resolution logic, and action items worked through a concurrent engineering-multidiscipline team. The normal tendency to use an intuitive, cut-and-try approach will usually prove to be costly, both in money and time and will reach a less than optimum, poorly understood answer. The SSME alternate high-pressure oxidizer turbopump development has had two complex problems critical to program success: (1) high synchronous vibrations and (2) excessive ball bearing wear. This paper will use these two problems as examples of this formal failure investigation approach. The results of the team's investigation provides insight into the complexity of the turbomachinery technical discipline interacting/sensitivities and the fine balance of competing investigations required to solve problems and guarantee program success. It is very important to the solution process that maximum use be made of the resources that both the contractor and Government can bring to the problem in a supporting and noncompeting way. There is no place for the not-invented-here attitude. The resources include, but are not limited to: (1) specially skilled professionals; (2) supporting technologies; (3) computational codes and capabilities; and (4) test and manufacturing facilities.

Developmental problems and their solution for the Space Shuttle main engine alternate liquid oxygen high-pressure turbopump: Anomaly or failure investigation the key

NASA Technical Reports Server (NTRS)

Ryan, R.; Gross, L. A.

1995-01-01

The Space Shuttle main engine (SSME) alternate high-pressure liquid oxygen pump experienced synchronous vibration and ball bearing life problems that were program threatening. The success of the program hinged on the ability to solve these development problems. The design and solutions to these problems are engirded in the lessons learned and experiences from prior programs, technology programs, and the ability to properly conduct failure or anomaly investigations. The failure investigation determines the problem cause and is the basis for recommending design solutions. For a complex problem, a comprehensive solution requires that formal investigation procedures be used, including fault trees, resolution logic, and action items worked through a concurrent engineering-multidiscipline team. The normal tendency to use an intuitive, cut-and-try approach will usually prove to be costly, both in money and time and will reach a less than optimum, poorly understood answer. The SSME alternate high-pressure oxidizer turbopump development has had two complex problems critical to program success: (1) high synchronous vibrations and (2) excessive ball bearing wear. This paper will use these two problems as examples of this formal failure investigation approach. The results of the team's investigation provides insight into the complexity of the turbomachinery technical discipline interacting/sensitivities and the fine balance of competing investigations required to solve problems and guarantee program success. It is very important to the solution process that maximum use be made of the resources that both the contractor and Government can bring to the problem in a supporting and noncompeting way. There is no place for the not-invented-here attitude. The resources include, but are not limited to: (1) specially skilled professionals; (2) supporting technologies; (3) computational codes and capabilities; and (4) test and manufacturing facilities.

128. COTTONWOOD CUT, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; ...

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

128. COTTONWOOD CUT, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; NORTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

Novel Model-Based Inquiry of Ionic Bonding in Alginate Hydrogels Used in Tissue Engineering for High School Students

ERIC Educational Resources Information Center

Bowles, Robby D.; Saroka, James M.; Archer, Shivaun D.; Bonassar, Lawrence J.

2012-01-01

Because of cost and time, it is difficult to relate to students how fundamental chemical principles are involved in cutting edge biomedical breakthroughs being reported in the national media. The laboratory exercise presented here is aimed at high school chemistry students and uses alginate hydrogels, a common material used in tissue engineering,…

127. COTTONWOOD CUT AREA, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, ...

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

127. COTTONWOOD CUT AREA, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; NORTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

35. PRATER GRADE ROAD VIEW, FACING NW. NOTE WEATHERING STEEL ...

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

35. PRATER GRADE ROAD VIEW, FACING NW. NOTE WEATHERING STEEL RAIL AND ROAD CUT IN DISTANCE. MONTEZUMA VALLEY OVERLOOK IS JUST TO RIGHT OF DISTANT ROAD CUT. - Mesa Verde National Park Main Entrance Road, Cortez, Montezuma County, CO

Current Launch Vehicle Practice and Data Base Assessment. Volume 1. Executive Summary and Report Body

DTIC Science & Technology

1989-06-01

resulted in an increase of the intermediate seal purge pressure, revised redlines, and a design change from a lift-off seal to a labyrinth seal design. This...engine 0003 caused fa&i!ure of the primary lox seal and an uncontained engine fire. The redline cut was set by a HPOTP overspeed. This failure...occurred as a result of undetected internal HEX damage caused during arc welding which resulted in an engine fire. HEX coil leakage resulted in an

In vitro comparison of the cutting efficiency and temperature production of ten different rotary cutting instruments. Part II: electric handpiece and comparison with turbine.

PubMed

Ercoli, Carlo; Rotella, Mario; Funkenbusch, Paul D; Russell, Scott; Feng, Changyong

2009-05-01

The cutting behavior of dental rotary cutting instruments is influenced by the handpiece used. While the turbine handpiece has been extensively tested in previous studies, limited published information exists on the use of rotary cutting instruments with the electric handpiece system and on possible interactions between rotary cutting instruments and handpiece type. The purpose of this study was to examine the cutting performance of a wide selection of rotary cutting instruments tested with the electric handpiece and compare the results with those of the air-turbine handpiece (Part I), identifying possible interactions between handpiece type and rotary cutting instruments. Ten groups of rotary cutting instruments (n=30) designed for tooth preparation were selected: 9 diamond (7 multi-use, 2 disposable) and 1 carbide. Macor blocks (n=75) were used as a substrate, and 4 cuts were made on each specimen, using a new rotary cutting instrument each time, for a total of 300 cuts. The cuts were performed with an electric handpiece (Intramatic Lux K200), with the same methods used in the Part I study. To qualitatively evaluate the rotary cutting instrument surface characteristics, 1 specimen from each group was examined 3 times with a scanning electron microscope (SEM): before use, then after use, but before being cleaned and sterilized, and finally, after ultrasonic cleaning. To compare rotary cutting instrument performance between the turbine and electric handpieces, the data were analyzed using 2-way ANOVA to study the main effects of the group of rotary cutting instruments, handpieces, and their interaction. For analysis of the significant main effect, 1-way ANOVA and Tukey's Studentized Range test were used (alpha=.05). Compared to the baseline temperature, all rotary cutting instruments showed a reduction of the temperature in the simulated pulp chamber when tested with the electric handpiece. The Great White Ultra (carbide bur) showed the highest rate of advancement (0.17 mm/s) and lowest applied load (108.35 g). Considering all rotary cutting instruments as a single group, the electric handpiece showed mean lower temperature (26.68 degrees C), higher rate of advancement (0.12 mm/s), and higher load (124.53 g) than the air-turbine handpiece (28.37 degrees C, 0.11 mm/s, and 121.7 g, respectively). Considering each single group of rotary cutting instruments, significant differences were found for the electric or air-turbine handpiece. The tested carbide bur showed greater cutting efficiency than the tested diamond rotary cutting instruments when used with the electric handpiece. The electric handpiece showed a higher cutting efficiency than the turbine, especially when used with the carbide bur, probably due to its greater torque.

Thermally Conductive Structural 2D Composite Materials

DTIC Science & Technology

2012-08-14

through-thickness thermal conductivity of up to 20 W/m.K. This novel structural prepreg material will be developed through engineering of an optimal fiber...with an EPON 862/Epikure W epoxy resin system to form unidirectional prepreg tapes. Each prepreg was then cut to 6 inch by 6 inch plies and...impregnated with an EPON 862/Epikure W epoxy resin system. The unidirectional prepreg tape was then cut into twelve 6 inch by 6 inch plies and

Unleashing Lessons: Sharing Stories About the Fine Art of Systems Engineering

NASA Technical Reports Server (NTRS)

Singer, Christopher E.

2010-01-01

NASA leaders have a responsibility to share their unique oral histories with junior-level employees on whom NASA's future depends. This presentation will give a few examples of how the imaginative, flexible art of systems engineering is as necessary to mission success as is the rigorous, disciplined side of engineering. Engineering space systems involves many disciplines propulsion, loads, dynamics, and so forth that are based on the foundations of scientific principles and methodology and the application of the laws of physics. The term rocket scientist is an apt term, considering that the underlying chemical properties of propellants and the subatomic properties of materials must be understood to harness the powerful energy necessary to escape Earth's gravity in machines that can withstand the stresses and forces to which they are subjected, not to mention the harsh space environments in which they must work. This is a simplistic, yet illustrative, explanation of the scientific side of the engineer s challenge. Bringing together these individual parts into a solid system goes beyond the science of engineering to employ the art of systems engineering. Systems engineers are known for their ability to integrate various solutions to meet or exceed challenging requirements. As the old adage goes, measure twice and cut once. The act of measuring is balancing rigid, inflexible requirements with creative compromises to attain the optimum solution to the challenge of space flight. Then, we cut out those answers that are too risky, expensive, dangerous, and so forth. The process of sharing stories about the little-discussed art of engineering, also known as the art of compromise, will equip the workforce to subjectively judge the best right answer from among the many presented, while objectively integrating the various piece parts into a unified whole.

Craterlike structures on the laser cut surface

NASA Astrophysics Data System (ADS)

Shulyatyev, V. B.; Orishich, A. M.

2017-10-01

Analysis of the laser cut surface morphology remain topical. It is related with the fact that the surface roughness is the main index of the cut quality. The present paper deals with the experimental study of the relatively unstudied type of defects on the laser cut surface, dimples, or craters. According to the measurement results, amount of craters per unit of the laser cut surface area rises as the sheet thickness rises. The crater diameter rises together with the sheet thickness and distance from the upper sheet edge. The obtained data permit concluding that the defects like craters are observed predominantly in the case of thick sheets. The results agree with the hypothesis of crater formation as impact structures resulting from the melt drops getting on the cut channel walls upon separation from the cut front by the gas flow.

Experimental response of Salix cuttings to different flow regimes due to human activities

NASA Astrophysics Data System (ADS)

Gorla, Lorenzo; Signarbieux, Constant; Turberg, Pascal; Buttler, Alexandre; Perona, Paolo

2014-05-01

Hydropower production and other human activities change the natural flow regime of rivers, in turn impacting the riparian environment. The main challenge in order to define eco-sustainable flows is to quantify the effects in terms of geomorphology and ecosystem adaptation. We present 2-years controlled experiments to investigate riparian vegetation (Salix Viminalis) response to forced water table changing dynamics, from one water regime to another, in a temperate region (Switzerland). Three synthetic flow regimes have been simulated and applied to three batteries of Salix cuttings growing outdoor within plastic pots, each about 1 meter tall. In 2012 one treatment simulated a minimal flow policy for small run-of-river hydropower plants, which drastically impacts the low and the medium-low components of the hydrograph, but not the extremes. In 2013 we confirmed and completed some of 2012 results, by reproducing typical hydropeaking effects due to dam management and focusing on daily water table variations and offsets. For both the seasons, after an initial period where all pots undergone the same oscillations in order to uniform the plants initial conditions, the experiment started, and the water dynamic was changed. Cuttings transitory response dynamics has been quantified by continuous sap flow and water potential measurements, and by regularly collecting growth parameters, as well as leaves photosynthesis, fluorescence, and pictures of each plant. At the end of the experiment, all cuttings were carefully removed and the both above and below ground biomass analyzed in detail. Particularly, the 3D root structure was obtained by High Resolution Computer Tomography. Our analyses revealed a clear dependence between roots distribution and water regime reflecting the need for adaptation, in agreement with field observations of Pasquale et al. (2012). In particular, an initial strong difference in terms of stress and growth performances was then followed by a later adjustment in the roots system, notably detected from tomographic images. Macroscopic effects in terms of growth parameters at weekly time step have found correspondence at higher time resolution in terms of sap flow and stem pressure, strengthening our results interpretation. REFERENCES - Pasquale et al. "Effects of streamflow variability on the vertical root density distribution of willow cutting experiments." Ecological Engineering 40 (2012): 167-172. - Gorla et al., "Transient response of Salix cuttings to changing water level regimes", WRR, submitted.

Effect of cutting fluids and cutting conditions on surface integrity and tool wear in turning of Inconel 713C

NASA Astrophysics Data System (ADS)

Hikiji, R.

2018-01-01

The trend toward downsizing of engines helps to increase the number of turbochargers around Europe. As for the turbocharger, the temperature of the exhaust gas is so high that the parts made of nickel base super alloy Inconel 713C are used as high temperature strength metals. External turning of Inconel 713C which is used as the actual automotive parts was carried out. The effect of the cutting fluids and cutting conditions on the surface integrity and tool wear was investigated, considering global environment and cost performance. As a result, in the range of the cutting conditions used this time, when the depth of cut was small, the good surface integrity and tool life were obtained. However, in the case of the large corner radius, it was found that the more the cutting length increased, the more the tool wear increased. When the cutting length is so large, the surface integrity and tool life got worse. As for the cutting fluids, it was found that the synthetic type showed better performance in the surface integrity and tool life than the conventional emulsion. However, it was clear that the large corner radius made the surface roughness and tool life good, but it affected the size error etc. in machining the workpiece held in a cantilever style.

CESAR robotics and intelligent systems research for nuclear environments

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

Mann, R.C.

1992-07-01

The Center for Engineering Systems Advanced Research (CESAR) at the Oak Ridge National Laboratory (ORNL) encompasses expertise and facilities to perform basic and applied research in robotics and intelligent systems in order to address a broad spectrum of problems related to nuclear and other environments. For nuclear environments, research focus is derived from applications in advanced nuclear power stations, and in environmental restoration and waste management. Several programs at CESAR emphasize the cross-cutting technology issues, and are executed in appropriate cooperation with projects that address specific problem areas. Although the main thrust of the CESAR long-term research is on developingmore » highly automated systems that can cooperate and function reliably in complex environments, the development of advanced human-machine interfaces represents a significant part of our research. 11 refs.« less

CESAR robotics and intelligent systems research for nuclear environments

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

Mann, R.C.

1992-01-01

The Center for Engineering Systems Advanced Research (CESAR) at the Oak Ridge National Laboratory (ORNL) encompasses expertise and facilities to perform basic and applied research in robotics and intelligent systems in order to address a broad spectrum of problems related to nuclear and other environments. For nuclear environments, research focus is derived from applications in advanced nuclear power stations, and in environmental restoration and waste management. Several programs at CESAR emphasize the cross-cutting technology issues, and are executed in appropriate cooperation with projects that address specific problem areas. Although the main thrust of the CESAR long-term research is on developingmore » highly automated systems that can cooperate and function reliably in complex environments, the development of advanced human-machine interfaces represents a significant part of our research. 11 refs.« less

Optical waveguides in lithium niobate: Recent developments and applications

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

Bazzan, Marco, E-mail: marco.bazzan@unipd.it; Sada, Cinzia, E-mail: cinzia.sada@unipd.it

The state of the art of optical waveguide fabrication in lithium niobate is reviewed, with particular emphasis on new technologies and recent applications. The attention is mainly devoted to recently developed fabrication methods, such as femtosecond laser writing, ion implantation, and smart cut waveguides as well as to the realization of waveguides with tailored functionalities, such as photorefractive or domain engineered structures. More exotic systems, such as reconfigurable and photorefractive soliton waveguides, are also considered. Classical techniques, such as Ti in-diffusion and proton exchange, are cited and briefly reviewed as a reference standpoint to highlight the recent developments. In allmore » cases, the application-oriented point of view is preferred, in order to provide the reader with an up-to date panorama of the vast possibilities offered by lithium niobate to integrated photonics.« less

Challenges of river basin management: Current status of, and prospects for, the River Danube from a river engineering perspective.

PubMed

Habersack, Helmut; Hein, Thomas; Stanica, Adrian; Liska, Igor; Mair, Raimund; Jäger, Elisabeth; Hauer, Christoph; Bradley, Chris

2016-02-01

In the Danube River Basin multiple pressures affect the river system as a consequence of river engineering works, altering both the river hydrodynamics and morphodynamics. The main objective of this paper is to identify the effects of hydropower development, flood protection and engineering works for navigation on the Danube and to examine specific impacts of these developments on sediment transport and river morphology. Whereas impoundments are characterised by deposition and an excess of sediment with remobilisation of fine sediments during severe floods, the remaining five free flowing sections of the Danube are experiencing river bed erosion of the order of several centimetres per year. Besides the effect of interruption of the sediment continuum, river bed degradation is caused by an increase in the sediment transport capacity following an increase in slope, a reduction of river bed width due to canalisation, prohibition of bank erosion by riprap or regressive erosion following base level lowering by flood protection measures and sediment dredging. As a consequence, the groundwater table is lowered, side-arms are disconnected, instream structures are lost and habitat quality deteriorates affecting the ecological status of valuable floodplains. The lack of sediments, together with cutting off meanders, leads also to erosion of the bed of main arms in the Danube Delta and coastal erosion. This paper details the causes and effects of river engineering measures and hydromorphological changes for the Danube. It highlights the importance of adopting a basin-wide holistic approach to river management and demonstrates that past management in the basin has been characterised by a lack of integration. To-date insufficient attention has been paid to the wide-ranging impacts of river engineering works throughout the basin: from the basin headwaters to the Danube Delta, on the Black Sea coast. This highlights the importance of new initiatives that seek to advance knowledge exchange and knowledge transfer within the basin to reach the goal of integrated basin management. Copyright © 2015 Elsevier B.V. All rights reserved.

Assuring quality in high-consequence engineering

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

Hoover, Marcey L.; Kolb, Rachel R.

2014-03-01

In high-consequence engineering organizations, such as Sandia, quality assurance may be heavily dependent on staff competency. Competency-dependent quality assurance models are at risk when the environment changes, as it has with increasing attrition rates, budget and schedule cuts, and competing program priorities. Risks in Sandia's competency-dependent culture can be mitigated through changes to hiring, training, and customer engagement approaches to manage people, partners, and products. Sandia's technical quality engineering organization has been able to mitigate corporate-level risks by driving changes that benefit all departments, and in doing so has assured Sandia's commitment to excellence in high-consequence engineering and national service.

125. COTTONWOOD CUT AREA, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, ...

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

125. COTTONWOOD CUT AREA, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; SOUTH VIEW OF CANAL. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

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

NASA Astrophysics Data System (ADS)

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

2009-11-01

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

Effect of micro-scale texturing on the cutting tool performance

NASA Astrophysics Data System (ADS)

Vasumathy, D.; Meena, Anil

2018-05-01

The present study is mainly focused on the cutting performance of the micro-scale textured carbide tools while turning AISI 304 austenitic stainless steel under dry cutting environment. The texture on the rake face of the carbide tools was fabricated by laser machining. The cutting performance of the textured tools was further compared with conventional tools in terms of cutting forces, tool wear, machined surface quality and chip curl radius. SEM and EDS analyses have been also performed to better understand the tool surface characteristics. Results show that the grooves help in breaking the tool-chip contact leading to a lesser tool-chip contact area which results in reduced iron (Fe) adhesion to the tool.

Response Ant Colony Optimization of End Milling Surface Roughness

PubMed Central

Kadirgama, K.; Noor, M. M.; Abd Alla, Ahmed N.

2010-01-01

Metal cutting processes are important due to increased consumer demands for quality metal cutting related products (more precise tolerances and better product surface roughness) that has driven the metal cutting industry to continuously improve quality control of metal cutting processes. This paper presents optimum surface roughness by using milling mould aluminium alloys (AA6061-T6) with Response Ant Colony Optimization (RACO). The approach is based on Response Surface Method (RSM) and Ant Colony Optimization (ACO). The main objectives to find the optimized parameters and the most dominant variables (cutting speed, feedrate, axial depth and radial depth). The first order model indicates that the feedrate is the most significant factor affecting surface roughness. PMID:22294914

Chevron cutting: Experiment with new runway mixtures

NASA Technical Reports Server (NTRS)

Tyran, K. (Compiler)

1978-01-01

Chevron cutting is shown to occur in different forms depending on the type of tire and the rubber on the running surface. Hardest wear is shown by the main tires of the B-747. Four defects occurred, in the form of two rip separation and two breakouts of the running surface. Tires capped by Thompson are more affected than any of the other rubber-capping fabrics. For Thompson tires, Chevron Cutting is greatly reduced with a fiberglass-rubber mixture. For Goodyear tires, it is eliminated with spiral wrap rubbercapping; resistance to damages through cuts seems to be more positive for Goodyear tires. For Mader tires, the extent of Chevron Cutting is generally smaller than for Thompson cappings.

Study of the Vibration Effect on the Cutting Forces and Roughness of Slub Milling

NASA Astrophysics Data System (ADS)

Germa, S.; Estrems Amestoy, M.; Sánchez Reinoso, H. T.; Franco Chumillas, P.

2009-11-01

For the planning process of slab milling operations, the vibration of the tool is the main factor to be considered. Under vibration conditions, the effect of the small displacements of the cutting tool and the cutting forces on the chip thickness must be minimized in order to avoid undesirable consequences, such as the fast flank wear, superficial defects and roughness increase. In this work, a mathematical model is developed to take into account the combined effect of the cutting tool and workpiece oscillation, as well as the axial errors of different milling tool tips. As a result, the model estimates the variation of the cutting forces and the ideal surface roughness.

Field testing of alternative carbide edge snow plow blades : [technical memorandum].

DOT National Transportation Integrated Search

2004-03-01

The Maine Department of Transportation uses almost 2,500 carbide cutting edges on its fleet of highway snow plow trucks : each winter. This represents almost 9,000 linear ft. of cutting edges and an annual expenditure of roughly $150,000 each winter ...

Prediction of surface roughness and cutting force under MQL turning of AISI 4340 with nano fluid by using response surface methodology

NASA Astrophysics Data System (ADS)

Patole, Pralhad B.; Kulkarni, Vivek V.

2018-06-01

This paper presents an investigation into the minimum quantity lubrication mode with nano fluid during turning of alloy steel AISI 4340 work piece material with the objective of experimental model in order to predict surface roughness and cutting force and analyze effect of process parameters on machinability. Full factorial design matrix was used for experimental plan. According to design of experiment surface roughness and cutting force were measured. The relationship between the response variables and the process parameters is determined through the response surface methodology, using a quadratic regression model. Results show how much surface roughness is mainly influenced by feed rate and cutting speed. The depth of cut exhibits maximum influence on cutting force components as compared to the feed rate and cutting speed. The values predicted from the model and experimental values are very close to each other.

The influence of machining condition and cutting tool wear on surface roughness of AISI 4340 steel

NASA Astrophysics Data System (ADS)

Natasha, A. R.; Ghani, J. A.; Che Haron, C. H.; Syarif, J.

2018-01-01

Sustainable machining by using cryogenic coolant as the cutting fluid has been proven to enhance some machining outputs. The main objective of the current work was to investigate the influence of machining conditions; dry and cryogenic, as well as the cutting tool wear on the machined surface roughness of AISI 4340 steel. The experimental tests were performed using chemical vapor deposition (CVD) coated carbide inserts. The value of machined surface roughness were measured at 3 cutting intervals; beginning, middle, and end of the cutting based on the readings of the tool flank wear. The results revealed that cryogenic turning had the greatest influence on surface roughness when machined at lower cutting speed and higher feed rate. Meanwhile, the cutting tool wear was also found to influence the surface roughness, either improving it or deteriorating it, based on the severity and the mechanism of the flank wear.

NASA Balloon Highlights 2015-2017

NASA Technical Reports Server (NTRS)

Fairbrother, Debora

2017-01-01

The NASA Balloon Program provides low-cost, quick response, near space access to NASAs science Community for conducting Cutting Edge Science Investigations. Serve as a technology development platform. Excellent training for NASA scientists and engineers.

Space Transportation Main Engine

NASA Technical Reports Server (NTRS)

Monk, Jan C.

1992-01-01

The topics are presented in viewgraph form and include the following: Space Transportation Main Engine (STME) definition, design philosophy, robust design, maximum design condition, casting vs. machined and welded forgings, operability considerations, high reliability design philosophy, engine reliability enhancement, low cost design philosophy, engine systems requirements, STME schematic, fuel turbopump, liquid oxygen turbopump, main injector, and gas generator. The major engine components of the STME and the Space Shuttle Main Engine are compared.

Rotation of intramedullary alignment rods affects distal femoral cutting plane in total knee arthroplasty.

PubMed

Maderbacher, Günther; Matussek, Jan; Keshmiri, Armin; Greimel, Felix; Baier, Clemens; Grifka, Joachim; Maderbacher, Hermann

2018-02-17

Intramedullary rods are widely used to align the distal femoral cut in total knee arthroplasty. We hypothesised that both coronal (varus/valgus) and sagittal (extension/flexion) cutting plane are affected by rotational changes of intramedullary femoral alignment guides. Distal femoral cuts using intramedullary alignment rods were simulated by means of a computer-aided engineering software in 4°, 6°, 8°, 10°, and 12° of valgus in relation to the femoral anatomical axis and 4° extension, neutral, as well as 4°, 8°, and 12° of flexion in relation to the femoral mechanical axis. This reflects the different angles between anatomical and mechanical axis in coronal and sagittal planes. To assess the influence of rotation of the alignment guide on the effective distal femoral cutting plane, all combinations were simulated with the rod gradually aligned from 40° of external to 40° of internal rotation. Rotational changes of the distal femoral alignment guides affect both the coronal and sagittal cutting planes. When alignment rods are intruded neutrally with regards to sagittal alignment, external rotation causes flexion, while internal rotation causes extension of the sagittal cutting plane. Simultaneously the coronal effect (valgus) decreases resulting in an increased varus of the cutting plane. However, when alignment rods are intruded in extension or flexion partly contradictory effects are observed. Generally the effect increases with the degree of valgus preset, rotation and flexion. As incorrect rotation of intramedullary alignment guides for distal femoral cuts causes significant cutting errors, exact rotational alignment is crucial. Coronal cutting errors in the distal femoral plane might result in overall leg malalignment, asymmetric extension gaps and subsequent sagittal cutting errors.

Slice-push, formation of grooves and the scale effect in cutting.

PubMed

Atkins, A G

2016-06-06

Three separate aspects of cutting are investigated which complement other papers on the mechanics of separation processes presented at this interdisciplinary Theo Murphy meeting. They apply in all types of cutting whether blades are sharp or blunt, and whether the material being cut is 'hard, stiff and strong' or 'soft, compliant and weak'. The first topic discusses why it is easier to cut when there is motion along (parallel to) the blade as well motion across (perpendicular to) the cutting edge, and the analysis is applied to optimization of blade geometries to produce minimum cutting forces and hence minimum damage to cut surfaces. The second topic concerns cutting with more than one edge with particular application to the formation of grooves in surfaces by hard pointed tools. The mechanics are investigated and applied to the topic of abrasive wear by hard particles. Traditional analyses say that abrasive wear resistance increases monotonically with the hardness of the workpiece, but we show that the fracture toughness of the surface material is also important, and that behaviour is determined by the toughness-to-hardness ratio rather than hardness alone. Scaling forms the third subject. As cutting is a branch of elasto-plastic fracture mechanics, cube-square energy scaling applies in which the important length scale is (ER/k (2)), where E is Young's modulus, R is the fracture toughness and k is the shear yield strength. Whether, in cutting, material is removed as ductile ribbons, as semi-ductile discontinuous chips, or by brittle 'knocking lumps out' is shown to depend on the depth of cut relative to this characteristic length parameter. Scaling in biology is called allometry and its relationship with engineering scaling is discussed. Some speculative predictions are made in relation to the action of teeth on food.

An investigation on co-axial water-jet assisted fiber laser cutting of metal sheets

NASA Astrophysics Data System (ADS)

Madhukar, Yuvraj K.; Mullick, Suvradip; Nath, Ashish K.

2016-02-01

Water assisted laser cutting has received significant attention in recent times with assurance of many advantages than conventional gas assisted laser cutting. A comparative study between co-axial water-jet and gas-jet assisted laser cutting of thin sheets of mild steel (MS) and titanium (Ti) by fiber laser is presented. Fiber laser (1.07 μm wavelength) was utilised because of its low absorption in water. The cut quality was evaluated in terms of average kerf, projected dross height, heat affected zone (HAZ) and cut surface roughness. It was observed that a broad range process parameter could produce consistent cut quality in MS. However, oxygen assisted cutting could produce better quality only with optimised parameters at high laser power and high cutting speed. In Ti cutting the water-jet assisted laser cutting performed better over the entire range of process parameters compared with gas assisted cutting. The specific energy, defined as the amount of laser energy required to remove unit volume of material was found more in case of water-jet assisted laser cutting process. It is mainly due to various losses associated with water assisted laser processing such as absorption of laser energy in water and scattering at the interaction zone.

Laser Cutting of Multilayered Kevlar Plates

NASA Astrophysics Data System (ADS)

Yilbas, B. S.; Al-Sulaiman, F.; Karakas, C.; Ahsan, M.

2007-12-01

Laser cutting of Kevlar plates, consisting of multilayered laminates, with different thicknesses are carried out. A mathematical model is developed to predict the kerf width, thermal efficiency, and specific energy requirements during cutting. Optical microscopy and Scanning Electron Microscopy (SEM) are employed to obtain the micrographs of the cutting sections. The kerf width size is measured and compared with the predictions. A factorial analysis is carried out to assess the affecting parameters on the mean kerf width and dimensionless damage sizes. It is found that the kerf width and damage sizes changes sharply when increasing cutting speed from 0.03 to 0.08 m/s. Thermal efficiency of the cutting process increases with increasing thickness and cutting speed while specific energy reduces with increasing thickness. The main effects of cutting parameters are found to be significant on the mean kerf width and dimensionless damage sizes, which is more pronounced for the workpiece bottom surface, where locally distributed char formation and sideways burning are observed.

Deformation of products cut on AWJ x-y tables and its suppression

NASA Astrophysics Data System (ADS)

Hlaváč, L. M.; Hlaváčová, I. M.; Plančár, Š.; Krenický, T.; Geryk, V.

2018-02-01

The aim of this study is namely investigation of the abrasive water jet (AWJ) cutting of column pieces on commercial x-y cutting machines with AWJ. The shape deformation in curved and/or stepped parts of cutting trajectories caused by both the trailback (declination angle) and the taper (inclination of cut walls) can be calculated from submitted analytical model. Some of the results were compared with data measured on samples cut on two types of commercial tables. The main motivation of this investigation is determination of the percentage difference between predicted and real distortion of cutting product, i.e. accuracy of prepared analytical model. Subsequently, the possibility of reduction of the distortion can be studied through implementation of the theoretical model into the control systems of the cutting machines with the system for cutting head tilting. Despite some limitations of the used AWJ machines the comparison of calculated dimensions with the real ones shows very good correlation of model and experimental data lying within the range of measurement uncertainty. Results on special device demonstrated that the shape deformation in curved parts of the cutting trajectory can be substantially reduced through tilting of the cutting head.

Preliminary results from field testing of alternative carbide edge snow plow blades.

DOT National Transportation Integrated Search

2003-04-01

The Maine Department of Transportation uses almost 2,500 carbide cutting edges on its fleet of highway snow plow trucks : each winter. This represents almost 9,000 linear ft. of cutting edges and an annual expenditure of roughly $150,000 each winter ...

120. COTTONWOOD CUT AREA, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, ...

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

120. COTTONWOOD CUT AREA, TWIN FALLS COUNTY, SOUTH OF KIMBERLY, IDAHO; OVERALL VIEW OF THE COTTONWOOD CREEK DRAW, SOUTH VIEW. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

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.

Investigation of the Hydraulic Characteristics of Capillary Elements of the Injector Head of Jet Engines under Conditions of Isothermal Flow of A Liquid

NASA Astrophysics Data System (ADS)

Nigodjuk, V. E.; Sulinov, A. V.

2018-01-01

The article presents the results of an experimental study of the hydraulic characteristics of capillary elements of the injector head of jet engines in isothermal fluid flow and the proposed method of their calculation. The main geometric dimensions of the capillaries in the experiment were changed in the following range: Inner diameter from 0.16 to 0.36 mm, length from 4.3 to 158 mm and relative length from 25 to 614 and the inlet edge of the capillaries: sharp or smooth the leading edge. As the working fluid during the tests were distilled water, acetone and ethyl alcohol. Based on the results of a study of the dependences for calculation of ultimate losses in laminar and turbulent flow regimes in capillary tubes with smooth and sharp edges input. The influence of surface tension forces on loss of input on a sharp cutting edge. Experimentally confirmed the possibility of calculating the linear coefficient of hydraulic resistance of capillary tubes with a diameter of 0.16-0.36 mm in isothermal stable during the known dependencies that are valid for hydrodynamically smooth round tube.

Study on the cutting mechanism and the brittle ductile transition model of isotropic pyrolyric graphite

NASA Astrophysics Data System (ADS)

Wang, Minghai; Wang, Hujun; Liu, Zhonghai

2011-05-01

Isotropic pyrolyric graphite (IPG) is a new kind of brittle material, it can be used for sealing the aero-engine turbine shaft and the ethylene high-temperature equipment. It not only has the general advantages of ordinal carbonaceous materials such as high temperature resistance, lubrication and abrasion resistance, but also has the advantages of impermeability and machinability that carbon/carbon composite doesn't have. Therefore, it has broad prospects for development. Mechanism of brittle-ductile transition of IPG is the foundation of precision cutting while the plastic deformation of IPG is the essential and the most important mechanical behavior of precision cutting. Using the theory of strain gradient, the mechanism of this material removal during the precision cutting is analyzed. The critical cutting thickness of IPG is calculated for the first time. Furthermore, the cutting process parameters such as cutting depth, feed rate which corresponding to the scale of brittle-ductile transition deformation of IPG are calculated. In the end, based on the theory of micromechanics, the deformation behaviors of IPG such as brittle fracture, plastic deformation and mutual transformation process are all simulated under the Sih.G.C fracture criterion. The condition of the simulation is that the material under the pressure-shear loading conditions .The result shows that the best angle during the IPG precision cutting is -30°. The theoretical analysis and the simulation result are validated by precision cutting experiments.

Investigation of the Effect of Tool Edge Geometry upon Cutting Variables, Tool Wear and Burr Formation Using Finite Element Simulation — A Progress Report

NASA Astrophysics Data System (ADS)

Sartkulvanich, Partchapol; Al-Zkeri, Ibrahim; Yen, Yung-Chang; Altan, Taylan

2004-06-01

This paper summarizes some of the progress made on FEM simulations of metal cutting processes conducted at the Engineering Research Center (ERC/NSM). Presented research focuses on the performance of various cutting edge geometries (hone and chamfer edges) for different tool materials and specifically on: 1) the effect of round and chamfer edge geometries on the cutting variables in machining carbon steels and 2) the effect of the edge hone size upon the flank wear and burr formation behavior in face milling of A356-T6 aluminum alloy. In the second task, an innovative design of edge preparation with varying hone size around the tool nose is also explored using FEM. In order to model three-dimensional conventional turning and face milling with two-dimensional orthogonal cutting simulations, 2D simulation cross-sections consisting of the cutting speed direction and chip flow direction are selected at different locations along the tool nose radius. Then the geometries of the hone and chamfer edges and their associated tool angles as well as uncut chip thickness are determined on these planes and employed in cutting simulations. The chip flow direction on the tool rake face are obtained by examining the wear grooves on the experimental inserts or estimated by using Oxley's approximation theory of oblique cutting. Simulation results are compared with the available experimental results (e.g. cutting forces) both qualitatively and quantitatively.

Designing to Save Energy

ERIC Educational Resources Information Center

Santamaria, Joseph W.

1977-01-01

While tripling the campus size of Alvin Community College in Texas, architects and engineers cut back on nonessential lighting, recaptured waste heat, insulated everything possible, and let energy considerations dictate the size and shape of the building. (Author/MLF)

Heat-Affected Zone Studies Of Thermally Cut Structural Steels

DOT National Transportation Integrated Search

1999-12-01

According to this primer, asset management is a systematic process of maintaining, upgrading, and operating physical assets cost-effectively. It combines engineering principles with sound business practices and economic theory, and it provides tools ...

Review on analog/radio frequency performance of advanced silicon MOSFETs

NASA Astrophysics Data System (ADS)

Passi, Vikram; Raskin, Jean-Pierre

2017-12-01

Aggressive gate-length downscaling of the metal-oxide-semiconductor field-effect transistor (MOSFET) has been the main stimulus for the growth of the integrated circuit industry. This downscaling, which has proved beneficial to digital circuits, is primarily the result of the need for improved circuit performance and cost reduction and has resulted in tremendous reduction of the carrier transit time across the channel, thereby resulting in very high cut-off frequencies. It is only in recent decades that complementary metal-oxide-semiconductor (CMOS) field-effect transistor (FET) has been considered as the radio frequency (RF) technology of choice. In this review, the status of the digital, analog and RF figures of merit (FoM) of silicon-based FETs is presented. State-of-the-art devices with very good performance showing low values of drain-induced barrier lowering, sub-threshold swing, high values of gate transconductance, Early voltage, cut-off frequencies, and low minimum noise figure, and good low-frequency noise characteristic values are reported. The dependence of these FoM on the device gate length is also shown, helping the readers to understand the trends and challenges faced by shorter CMOS nodes. Device performance boosters including silicon-on-insulator substrates, multiple-gate architectures, strain engineering, ultra-thin body and buried-oxide and also III-V and 2D materials are discussed, highlighting the transistor characteristics that are influenced by these boosters. A brief comparison of the two main contenders in continuing Moore’s law, ultra-thin body buried-oxide and fin field-effect transistors are also presented. The authors would like to mention that despite extensive research carried out in the semiconductor industry, silicon-based MOSFET will continue to be the driving force in the foreseeable future.

Theoretical study of cut area of reduction of large surfaces of rotation parts on machines with rotary cutters “Extra”

NASA Astrophysics Data System (ADS)

Bondarenko, J. A.; Fedorenko, M. A.; Pogonin, A. A.

2018-03-01

Large parts can be treated without disassembling machines using “Extra”, having technological and design challenges, which differ from the challenges in the processing of these components on the stationary machine. Extension machines are used to restore large parts up to the condition allowing one to use them in a production environment. To achieve the desired accuracy and surface roughness parameters, the surface after rotary grinding becomes recoverable, which greatly increases complexity. In order to improve production efficiency and productivity of the process, the qualitative rotary processing of the machined surface is applied. The rotary cutting process includes a continuous change of the cutting edge surfaces. The kinematic parameters of a rotary cutting define its main features and patterns, the cutting operation of the rotary cutting instrument.

The Impact Of Surface Shape Of Chip-Breaker On Machined Surface

NASA Astrophysics Data System (ADS)

Šajgalík, Michal; Czán, Andrej; Martinček, Juraj; Varga, Daniel; Hemžský, Pavel; Pitela, David

2015-12-01

Machined surface is one of the most used indicators of workpiece quality. But machined surface is influenced by several factors such as cutting parameters, cutting material, shape of cutting tool or cutting insert, micro-structure of machined material and other known as technological parameters. By improving of these parameters, we can improve machined surface. In the machining, there is important to identify the characteristics of main product of these processes - workpiece, but also the byproduct - the chip. Size and shape of chip has impact on lifetime of cutting tools and its inappropriate form can influence the machine functionality and lifetime, too. This article deals with elimination of long chip created when machining of shaft in automotive industry and with impact of shape of chip-breaker on shape of chip in various cutting conditions based on production requirements.

Physiological, volatile, and SEM surface effects resulting from cutting and dipping treatments in cantaloupe.

PubMed

Beaulieu, John C; Ingber, Bruce F; Lea, Jeanne M

2011-09-01

Previous research examined sanitation treatments on cut cantaloupe tissue to deliver germicidal and food safety effects. However, an apparent compromise between volatile loss and treatment/sampling efficacy appeared. Subsequently, a physiological and volatile reassessment of thinly sliced tissue against cubes was performed in cantaloupe tissue. Thin sliced cantaloupe L* decreased 27.5%, 40.5%, and 52.9% in 3, 2, and 1 mm thickness, respectively, compared with cut cubes after 3 d. Overall color (C) decreased in freshly prepared cubes (2.4%) and slices (14.4%) that were washed in cold water. Surface area per unit volume (SA: vol) in slices was 4.1 times greater than typical cubes, as reflected by substantial water loss (20.4%, 9.5%, and 6.7% in 1, 2 and 3-mm slices, respectively) after 1 d at 5 °C. Rinsing cubes and thin-slices with 5 °C deionized water resulted in roughly 15% soluble solids loss. SEM indicated 65.4% reduced cell size in 1-d old thin slices, evidenced by excessive cell damage and desiccation compared with stored fresh-cut cubes. In thin-sliced tissue exposed 15 min to an open atmosphere (mimic sanitation treatments), total esters decreased 92.8% and 95.8%, respectively, after 1 and 3 d storage at 5 °C. Washing tissue provided a boundary layer that reduced short-term ester losses in slices and cubes. Excessive cutting, sanitation treatment regimes, and storage can radically alter the desirable volatile profile of cut cantaloupe. Reduction of tissue size to maximize food-safety sanitation efficacy or delivering items to a niche market will need substantial work to engineer equipment and develop protocols to insure that product quality and volatiles are not compromised. We have demonstrated that cutting method and sampling protocol are critically important when using volatiles as a means by which to assess or interpret stress response and ascribe fresh-cut quality. Reduction of tissue size to maximize food-safety sanitation efficacy (for example, thin slices) will need substantial work to engineer equipment and design protocols to insure product quality and volatile profiles are not compromised. Journal of Food Science © 2011 Institute of Food Technologists® No claim to original US government works.

Setting Meaningful Criterion-Reference Cut Scores as an Effective Professional Development

ERIC Educational Resources Information Center

Munyofu, Paul

2010-01-01

The state of Pennsylvania, like many organizations interested in performance improvement, routinely engages in professional development activities. Educators in this hands-on activity engaged in setting meaningful criterion-referenced cut scores for career and technical education assessments using two methods. The main purposes of this study were…

EVALUATION OF THE CARBON FOOTPRINT OF INNOVATIVE WATER MAIN REHABILITATION TECHNOLOGIES VS OPEN CUT METHODS

EPA Science Inventory

A major benefit of trenchless rehabilitation technologies touted by many practitioners when comparing their products with traditional open cut construction methods is lower carbon dioxide (CO₂) emissions. In an attempt to verify these claims, multiple tools have been d...

EVALUATION OF THE CARBON FOOTPRINT OF INNOVATIVE WATER MAIN REHABILITATION TECHNOLOGIES VS. OPEN CUT METHODS

EPA Science Inventory

A major benefit of trenchless rehabilitation technologies touted by many practitioners when comparing their products with tradition open cut construction methods is lower carbon dioxide (CO₂) emissions. In an attempt to verify these claims, multiple tools have been dev...

Designing a place for automation.

PubMed

Bazzoli, F

1995-05-01

Re-engineering is a hot topic in health care as market forces increase pressure to cut costs. Providers and payers that are redesigning their business processes are counting on information systems to help achieve simplification and make large gains in efficiency. But these same organizations say they're reluctant to make large upfront investments in information systems until they know exactly what role technology will play in the re-engineered entity.

Advanced Turbine Engine Seal Test

DTIC Science & Technology

1976-07-01

Transpiration- Cooled Shroud Segments. 67. ATEST Shroud Rub Pin Heights and Mid-Chord Runout . 68. Locations of Nine-Point Runout Check on Shroud Surface...69. ATEST Shroud Leading Edge Runout . 70. ATEST Shroud Trailing Edge Runout . 71. ATEST Shroud Support Posttest Runout . 72. ATEST Shroud Flow Zones...at General Electric on many prior engines with good success. It Involves the use of a grinding wheel in conjunction with a cutting fluid which is

Laser cutting: industrial relevance, process optimization, and laser safety

NASA Astrophysics Data System (ADS)

Haferkamp, Heinz; Goede, Martin; von Busse, Alexander; Thuerk, Oliver

1998-09-01

Compared to other technological relevant laser machining processes, up to now laser cutting is the application most frequently used. With respect to the large amount of possible fields of application and the variety of different materials that can be machined, this technology has reached a stable position within the world market of material processing. Reachable machining quality for laser beam cutting is influenced by various laser and process parameters. Process integrated quality techniques have to be applied to ensure high-quality products and a cost effective use of the laser manufacturing plant. Therefore, rugged and versatile online process monitoring techniques at an affordable price would be desirable. Methods for the characterization of single plant components (e.g. laser source and optical path) have to be substituted by an omnivalent control system, capable of process data acquisition and analysis as well as the automatic adaptation of machining and laser parameters to changes in process and ambient conditions. At the Laser Zentrum Hannover eV, locally highly resolved thermographic measurements of the temperature distribution within the processing zone using cost effective measuring devices are performed. Characteristic values for cutting quality and plunge control as well as for the optimization of the surface roughness at the cutting edges can be deducted from the spatial distribution of the temperature field and the measured temperature gradients. Main influencing parameters on the temperature characteristic within the cutting zone are the laser beam intensity and pulse duration in pulse operation mode. For continuous operation mode, the temperature distribution is mainly determined by the laser output power related to the cutting velocity. With higher cutting velocities temperatures at the cutting front increase, reaching their maximum at the optimum cutting velocity. Here absorption of the incident laser radiation is drastically increased due to the angle between the normal of the cutting front and the laser beam axis. Beneath process optimization and control further work is focused on the characterization of particulate and gaseous laser generated air contaminants and adequate safety precautions like exhaust and filter systems.

Qualitative Importance Measures of Systems Components - A New Approach and Its Applications

NASA Astrophysics Data System (ADS)

Chybowski, Leszek; Gawdzińska, Katarzyna; Wiśnicki, Bogusz

2016-12-01

The paper presents an improved methodology of analysing the qualitative importance of components in the functional and reliability structures of the system. We present basic importance measures, i.e. the Birnbaum's structural measure, the order of the smallest minimal cut-set, the repetition count of an i-th event in the Fault Tree and the streams measure. A subsystem of circulation pumps and fuel heaters in the main engine fuel supply system of a container vessel illustrates the qualitative importance analysis. We constructed a functional model and a Fault Tree which we analysed using qualitative measures. Additionally, we compared the calculated measures and introduced corrected measures as a tool for improving the analysis. We proposed scaled measures and a common measure taking into account the location of the component in the reliability and functional structures. Finally, we proposed an area where the measures could be applied.

The cost of performance - A comparison of the space transportation main engine and the Space Shuttle main engine

NASA Technical Reports Server (NTRS)

Barisa, B. B.; Flinchbaugh, G. D.; Zachary, A. T.

1989-01-01

This paper compares the cost of the Space Shuttle Main Engine (SSME) and the Space Transportation Main Engine (STME) proposed by the Advanced Launch System Program. A brief description of the SSME and STME engines is presented, followed by a comparison of these engines that illustrates the impact of focusing on acceptable performance at minimum cost (as for the STME) or on maximum performance (as for the SSME). Several examples of cost reduction methods are presented.

Feather seal slot for vanes

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

Del Mastro, B. P.; Eckart, F.

1985-10-22

The slots for accommodating feather seals in the turbine vanes of a gas turbine engine has the end thereof sealed off by use of weld wire inserted into the slot and simultaneously welded and cut to the required length.

High speed, self-acting shaft seal. [for use in turbine engines

NASA Technical Reports Server (NTRS)

Ludwig, L. P.; Hady, W. F. (Inventor)

1975-01-01

A high-speed, self-acting circumferential type shaft seal for use in turbine engines is disclosed. One or more conventional circumferential ring seals having a central aperture are mounted in a housing. In three of the four embodiments of the invention, a helical groove and one or more dam seals are cut in the inner cylindrical surface of the one or more ring seals. In a fourth embodiment, two or more lift pads are disposed in surface contact with the inner cylindrical surface of the seal rings. To the outside of the lift pads, two dam seals are cut in the inner cylindrical surface of two of the ring seals. In each of the embodiments, a net outward radial force was produced during rotation of the turbine causing the ring seals to lift out of contact with the turbine shaft to minimize wear of the ring seals.

Environment-friendly drilling operation technology

NASA Astrophysics Data System (ADS)

Luo, Huaidong; Jing, Ning; Zhang, Yanna; Huang, Hongjun; Wei, Jun

2017-01-01

Under the circumstance that international safety and environmental standards being more and more stringent, drilling engineering is facing unprecedented challenges, the extensive traditional process flow is no longer accepted, the new safe and environment-friendly process is more suitable to the healthy development of the industry. In 2015, CNPCIC adopted environment-friendly drilling technology for the first time in the Chad region, ensured the safety of well control, at the same time increased the environmental protection measure, reduced the risk of environmental pollution what obtain the ratification from local government. This technology carries out recovery and disposal of crude oil, cuttings and mud without falling on the ground. The final products are used in road and well site construction, which realizes the reutilization of drilling waste, reduces the operating cost, and provides a strong technical support for cost-cutting and performance-increase of drilling engineering under low oil price.

Surface Roughness Optimization Using Taguchi Method of High Speed End Milling For Hardened Steel D2

NASA Astrophysics Data System (ADS)

Hazza Faizi Al-Hazza, Muataz; Ibrahim, Nur Asmawiyah bt; Adesta, Erry T. Y.; Khan, Ahsan Ali; Abdullah Sidek, Atiah Bt.

2017-03-01

The main challenge for any manufacturer is to achieve higher quality of their final products with maintains minimum machining time. In this research final surface roughness analysed and optimized with maximum 0.3 mm flank wear length. The experiment was investigated the effect of cutting speed, feed rate and depth of cut on the final surface roughness using D2 as a work piece hardened to 52-56 HRC, and coated carbide as cutting tool with higher cutting speed 120-240 mm/min. The experiment has been conducted using L9 design of Taguchi collection. The results have been analysed using JMP software.

Shuttle Propulsion System Major Events and the Final 22 Flights

NASA Technical Reports Server (NTRS)

Owen, James W.

2011-01-01

Numerous lessons have been documented from the Space Shuttle Propulsion elements. Major events include loss of the Solid Rocket Boosters (SRB's) on STS-4 and shutdown of a Space Shuttle Main Engine (SSME) during ascent on STS-51F. On STS-112 only half the pyrotechnics fired during release of the vehicle from the launch pad, a testament for redundancy. STS-91 exhibited freezing of a main combustion chamber pressure measurement and on STS-93 nozzle tube ruptures necessitated a low liquid level oxygen cut off of the main engines. A number of on pad aborts were experienced during the early program resulting in delays. And the two accidents, STS-51L and STS-107, had unique heritage in history from early program decisions and vehicle configuration. Following STS-51L significant resources were invested in developing fundamental physical understanding of solid rocket motor environments and material system behavior. And following STS-107, the risk of ascent debris was better characterized and controlled. Situational awareness during all mission phases improved, and the management team instituted effective risk assessment practices. The last 22 flights of the Space Shuttle, following the Columbia accident, were characterized by remarkable improvement in safety and reliability. Numerous problems were solved in addition to reduction of the ascent debris hazard. The Shuttle system, though not as operable as envisioned in the 1970's, successfully assembled the International Space Station (ISS). By the end of the program, the remarkable Space Shuttle Propulsion system achieved very high performance, was largely reusable, exhibited high reliability, and was a heavy lift earth to orbit propulsion system. During the program a number of project management and engineering processes were implemented and improved. Technical performance, schedule accountability, cost control, and risk management were effectively managed and implemented. Award fee contracting was implemented to provide performance incentives. The Certification of Flight Readiness and Mission Management processes became very effective. A key to the success of the propulsion element projects was related to relationships between the MSFC project office and support organizations with their counterpart contractor organizations. The teams worked diligently to understand and satisfy requirements and achieve mission success.

Cutting the Cord

NASA Technical Reports Server (NTRS)

2004-01-01

This animation shows the view from the front hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting off the front lander petal. Before this crucial turn could take place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

Cutting the Cord-2

NASA Technical Reports Server (NTRS)

2004-01-01

This animation shows the view from the rear hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting from the front lander petal. Before this crucial turn took place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

Modeling the milling tool wear by using an evolutionary SVM-based model from milling runs experimental data

NASA Astrophysics Data System (ADS)

Nieto, Paulino José García; García-Gonzalo, Esperanza; Vilán, José Antonio Vilán; Robleda, Abraham Segade

2015-12-01

The main aim of this research work is to build a new practical hybrid regression model to predict the milling tool wear in a regular cut as well as entry cut and exit cut of a milling tool. The model was based on Particle Swarm Optimization (PSO) in combination with support vector machines (SVMs). This optimization mechanism involved kernel parameter setting in the SVM training procedure, which significantly influences the regression accuracy. Bearing this in mind, a PSO-SVM-based model, which is based on the statistical learning theory, was successfully used here to predict the milling tool flank wear (output variable) as a function of the following input variables: the time duration of experiment, depth of cut, feed, type of material, etc. To accomplish the objective of this study, the experimental dataset represents experiments from runs on a milling machine under various operating conditions. In this way, data sampled by three different types of sensors (acoustic emission sensor, vibration sensor and current sensor) were acquired at several positions. A second aim is to determine the factors with the greatest bearing on the milling tool flank wear with a view to proposing milling machine's improvements. Firstly, this hybrid PSO-SVM-based regression model captures the main perception of statistical learning theory in order to obtain a good prediction of the dependence among the flank wear (output variable) and input variables (time, depth of cut, feed, etc.). Indeed, regression with optimal hyperparameters was performed and a determination coefficient of 0.95 was obtained. The agreement of this model with experimental data confirmed its good performance. Secondly, the main advantages of this PSO-SVM-based model are its capacity to produce a simple, easy-to-interpret model, its ability to estimate the contributions of the input variables, and its computational efficiency. Finally, the main conclusions of this study are exposed.

Think before You Cut

ERIC Educational Resources Information Center

Pettifor, Ann

2010-01-01

With the main political parties set on reducing public spending, one might be forgiven for supposing that "savage" cuts are the only way forward. However, the author believes there are alternatives, and that is why public education about the financial system is so important. Today, UK is trying to clear up a mess--a mess made by the…

Expedition 41 Preflight

NASA Image and Video Library

2014-09-23

Expedition 41 Flight Engineer Barry Wilmore gets his hair cut at the Cosmonaut Hotel, on Tuesday, Sept. 23, 2014, at the Baikonur Cosmodrome in Kazakhstan. Launch of the Soyuz is scheduled for Sept. 26 and will send Barry Wilmore of NASA, Soyuz Commander Alexander Samokutyaev of the Russian Federal Space Agency (Roscosmos), and Flight Engineer Elena Serova of Roscosmos to the International Space Station for a five and a half month stay. Photo Credit: (NASA/Dr. Peter Bauer)

1400879

NASA Image and Video Library

2014-08-13

AIDING IN THE OFFICIAL BUILDING 4220 RIBBON-CUTTING ARE, FROM LEFT, JOHN HONEYCUTT, DEPUTY MANAGER OF THE SPACE LAUNCH SYSTEM PROGRAM OFFICE; LT. COL. TOM NELSON, DEPUTY COMMANDER OF THE U.S. ARMY CORPS OF ENGINEERS-MOBILE DISTRICT; U.S. SEN. JEFF SESSIONS OF ALABAMA; MARSHALL CENTER DIRECTOR PATRICK SCHEUERMANN; U.S. REP. MO BROOKS OF ALABAMA'S 5TH DISTRICT; MARSHALL DEPUTY DIRECTOR TERESA VANHOOSER; AND MARSHALL ENGINEER DAVID SKRIDULIS, TEAM LEAD FOR THE FACILITIES MANAGEMENT OFFICE'S CIVIL STRUCTURAL GROUP.

Aircraft energy efficiency. Overview

NASA Technical Reports Server (NTRS)

1981-01-01

Six advanced technology development projects that could cut fuel consumption of future civil air transports by as much as 50 percent are highlighted. These include improved engine components; better engine design; thin short blades for turboprop aircaft; using composite primary structures for weight reduction; the use of supercritical wings, higher aspect ratio, and winglets for improved aerodynamics; active controls; and laminar flow control. The time span of each of the six efforts and NASA's expected expenditures are also discussed.

Investigation of Volatiles Emitted from Freshly Cut Onions (Allium cepa L.) by Real Time Proton-Transfer Reaction-Mass Spectrometry (PTR-MS)

PubMed Central

Løkke, Mette Marie; Edelenbos, Merete; Larsen, Erik; Feilberg, Anders

2012-01-01

Volatile organic compounds (VOCs) in cut onions (Allium cepa L.) were continuously measured by PTR-MS during the first 120 min after cutting. The headspace composition changed rapidly due to the very reactive volatile sulfurous compounds emitted from onion tissue after cell disruption. Mass spectral signals corresponding to propanethial S-oxide (the lachrymatory factor) and breakdown products of this compound dominated 0–10 min after cutting. Subsequently, propanethiol and dipropyl disulfide predominantly appeared, together with traces of thiosulfinates. The concentrations of these compounds reached a maximum at 60 min after cutting. Propanethiol was present in highest concentrations and had an odor activity value 20 times higher than dipropyl disulfide. Thus, propanethiol is suggested to be the main source of the characteristic onion odor. Monitoring the rapid changes of VOCs in the headspace of cut onion necessitates a high time resolution, and PTR-MS is demonstrated to be a very suitable method for monitoring the headspace of freshly cut onions directly after cutting without extraction or pre-concentration. PMID:23443367

Stennis certifies final shuttle engine

NASA Image and Video Library

2008-10-22

Steam blasts out of the A-2 Test Stand at Stennis Space Center on Oct. 22 as engineers begin a certification test on engine 2061, the last space shuttle main flight engine scheduled to be built. Since 1975, Stennis has tested every space shuttle main engine used in the program - about 50 engines in all. Those engines have powered more than 120 shuttle missions - and no mission has failed as a result of engine malfunction. For the remainder of 2008 and throughout 2009, Stennis will continue testing of various space shuttle main engine components.

Electro-chemical grinding

NASA Technical Reports Server (NTRS)

Feagans, P. L.

1972-01-01

Electro-chemical grinding technique has rotation speed control, constant feed rates, and contour control. Hypersonic engine parts of nickel alloys can be almost 100% machined, keeping tool pressure at virtual zero. Technique eliminates galling and permits constant surface finish and burr-free interrupted cutting.

iss028e035028

NASA Image and Video Library

2011-08-27

ISS028-E-035028 (27 Aug. 2011) --- NASA astronaut Mike Fossum, Expedition 28 flight engineer, trims astronaut Ron Garan's hair in the Tranquility node of the International Space Station. Fossum used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Garrett Reisman, Expedition 17 Haircut in Harmony

NASA Image and Video Library

2008-05-04

ISS017-E-006253 (4 May 2008) --- Astronaut Garrett Reisman, Expedition 17 flight engineer, trims his hair in the Harmony node of the International Space Station, using hair clippers fashioned with a vacuum device to garner freshly cut hair.

iss028e035053

NASA Image and Video Library

2011-08-27

ISS028-E-035053 (27 Aug. 2011) --- NASA astronaut Ron Garan, Expedition 28 flight engineer, trims astronaut Mike Fossum's hair in the Tranquility node of the International Space Station. Garan used hair clippers fashioned with a vacuum device to garner freshly cut hair.

How young trees cope with removal of whole or parts of shoots: an analysis of local and distant responses to pruning in 1-year-old apple (Malus xdomestica; Rosaceae) trees.

PubMed

Fumey, Damien; Lauri, Pierre-Éric; Guédon, Yann; Godin, Christophe; Costes, Evelyne

2011-11-01

Manipulation of tree architecture by pruning provides an experimental context to analyze architectural plasticity resulting from competition between developing organs. The objective of this study was to quantify the effects of the removal of all or part of shoots through pruning on the redistribution of growth and flowering at spatial and temporal levels. Two types of pruning cuts were applied: (1) heading cuts of either the main stem or laterals and (2) thinning cuts (i.e., complete removal) of laterals. These two types of cuts were applied in summer and winter on 1-yr-old cultivars of Fuji and Braeburn apple trees. Tree topology and geometry were described over 3 years, and responses were analyzed for both local and distant scales. Heading cuts induced quasi-deterministic local responses on pruned axes, whereas responses to thinning cuts were more variable. For the main stem and laterals, responses over greater spatial and temporal scales were highlighted with (1) stronger growth the year after summer pruning and (2) modification of branching and flowering along the unpruned parts after winter pruning. Pruning typically induced growth redistribution toward traumatic reiterations and enhanced growth of the remaining unpruned axes with a concomitant decrease of flowering and cambial growth. Although results could be interpreted in relation to the root-shoot balance, tree responses appeared highly cultivar-specific.

Experimental and numerical investigations on the temperature distribution in PVD AlTiN coated and uncoated Al2O3/TiCN mixed ceramic cutting tools in hard turning of AISI 52100 steel

NASA Astrophysics Data System (ADS)

Sateesh Kumar, Ch; Patel, Saroj Kumar; Das, Anshuman

2018-03-01

Temperature generation in cutting tools is one of the major causes of tool failure especially during hard machining where machining forces are quite high resulting in elevated temperatures. Thus, the present work investigates the temperature generation during hard machining of AISI 52100 steel (62 HRC hardness) with uncoated and PVD AlTiN coated Al2O3/TiCN mixed ceramic cutting tools. The experiments were performed on a heavy duty lathe machine with both coated and uncoated cutting tools under dry cutting environment. The temperature of the cutting zone was measured using an infrared thermometer and a finite element model has been adopted to predict the temperature distribution in cutting tools during machining for comparative assessment with the measured temperature. The experimental and numerical results revealed a significant reduction of cutting zone temperature during machining with PVD AlTiN coated cutting tools when compared to uncoated cutting tools during each experimental run. The main reason for decrease in temperature for AlTiN coated tools is the lower coefficient of friction offered by the coating material which allows the free flow of the chips on the rake surface when compared with uncoated cutting tools. Further, the superior wear behaviour of AlTiN coating resulted in reduction of cutting temperature.

Evaluation of laser cutting process with auxiliary gas pressure by soft computing approach

NASA Astrophysics Data System (ADS)

Lazov, Lyubomir; Nikolić, Vlastimir; Jovic, Srdjan; Milovančević, Miloš; Deneva, Heristina; Teirumenieka, Erika; Arsic, Nebojsa

2018-06-01

Evaluation of the optimal laser cutting parameters is very important for the high cut quality. This is highly nonlinear process with different parameters which is the main challenge in the optimization process. Data mining methodology is one of most versatile method which can be used laser cutting process optimization. Support vector regression (SVR) procedure is implemented since it is a versatile and robust technique for very nonlinear data regression. The goal in this study was to determine the optimal laser cutting parameters to ensure robust condition for minimization of average surface roughness. Three cutting parameters, the cutting speed, the laser power, and the assist gas pressure, were used in the investigation. As a laser type TruLaser 1030 technological system was used. Nitrogen as an assisted gas was used in the laser cutting process. As the data mining method, support vector regression procedure was used. Data mining prediction accuracy was very high according the coefficient (R2) of determination and root mean square error (RMSE): R2 = 0.9975 and RMSE = 0.0337. Therefore the data mining approach could be used effectively for determination of the optimal conditions of the laser cutting process.

Female genital cutting in Hargeisa, Somaliland: is there a move towards less severe forms?

PubMed

Lunde, Ingvild Bergom; Sagbakken, Mette

2014-05-01

According to several sources, little progress is being made in eliminating the cutting of female genitalia. This paper, based on qualitative interviews and observations, explores perceptions of female genital cutting and elimination of the phenomenon in Hargeisa, Somaliland. Two main groups of participants were interviewed: (1) 22 representatives of organisations whose work directly relates to female genital cutting; and (2) 16 individuals representing different groups of society. It was found that there is an increasing use of medical staff and equipment when a girl undergoes the procedure of female genital cutting; the use of terminology is crucial in understanding current perceptions of female genital cutting; religion is both an important barrier and facilitator of elimination; and finally, traditional gender structures are currently being challenged in Hargeisa. The findings of this study suggest that it is important to consider current perceptions on practices of female genital cutting and on abandonment of female genital cutting, in order to gain useful knowledge on the issue of elimination. The study concludes that elimination of female genital cutting is a multifaceted process which is constantly negotiated in a diversity of social settings. Copyright © 2014 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

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

The U.S. Department of Energy's (DOE) Co-Optimization of Fuels & Engines (Co-Optima) initiative is accelerating the introduction of affordable, scalable, and sustainable fuels and high-efficiency, low-emission engines with a first-of-its-kind effort to simultaneously tackle fuel and engine research and development (R&D). This report summarizes accomplishments in the first year of the project. Co-Optima is conducting concurrent research to identify the fuel properties and engine design characteristics needed to maximize vehicle performance and affordability, while deeply cutting emissions. Nine national laboratories - the National Renewable Energy Laboratory and Argonne, Idaho, Lawrence Berkeley, Lawrence Livermore, Los Alamos, Oak Ridge, Pacific Northwest, andmore » Sandia National Laboratories - are collaborating with industry and academia on this groundbreaking research.« less

Mechanical Engineering Department engineering research: Annual report, FY 1986

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

Denney, R.M.; Essary, K.L.; Genin, M.S.

1986-12-01

This report provides information on the five areas of research interest in LLNL's Mechanical Engineering Department. In Computer Code Development, a solid geometric modeling program is described. In Dynamic Systems and Control, structure control and structure dynamics are discussed. Fabrication technology involves machine cutting, interferometry, and automated optical component manufacturing. Materials engineering reports on composite material research and measurement of molten metal surface properties. In Nondestructive Evaluation, NMR, CAT, and ultrasound machines are applied to manufacturing processes. A model for underground collapse is developed. Finally, an alternative heat exchanger is investigated for use in a fusion power plant. Separate abstractsmore » were prepared for each of the 13 reports in this publication. (JDH)« less

Study on the Optimal Groove Shape and Glue Material for Fiber Bragg Grating Measuring Bolts.

PubMed

Zhao, Yiming; Zhang, Nong; Si, Guangyao; Li, Xuehua

2018-06-02

Fiber Bragg grating (FBG) measuring bolts, as a useful tool to evaluate the behaviors of steel bolts in underground engineering, can be manufactured by gluing the FBG sensors inside the grooves, which are usually symmetrical cuts along the steel bolt rod. The selection of the cut shape and the glue types could perceivably affect the final supporting strength of the bolts. Unfortunately, the impact of cut shape and glue type on bolting strength is not yet clear. In this study, based on direct tension tests, full tensile load⁻displacement curves of rock bolts with different groove shapes were obtained and analyzed. The effects of groove shape on the bolt strength were discussed, and the stress redistribution in the cross-section of a rock bolt with different grooves was simulated using ANSYS. The results indicated that the trapezoidal groove is best for manufacturing the FBG bolt due to its low reduction of supporting strength. Four types of glues commonly used for the FBG sensors were assessed by conducting tensile tests on the mechanical testing and simulation system and the static and dynamic optical interrogators system. Using linear regression analysis, the relationship between the reflected wavelength of FBG sensors and tensile load was obtained. Practical recommendations for glue selection in engineering practice are also provided.

Experimental investigations of the effects of cutting angle on chattering of a flexible manipulator

NASA Technical Reports Server (NTRS)

Lew, J.; Huggins, J.; Magee, D.; Book, W.

1991-01-01

When a machine tool is mounted at the tip of a robotic manipulator, the manipulator becomes more flexible (the natural frequencies are lowered). Moreover, for a given flexible manipulator, its compliance will be different depending on feedback gains, configurations, and direction of interest. Here, the compliance of a manipulator is derived analytically, and its magnitude is represented as a compliance ellipsoid. Then, using a two-link flexible manipulator with an abrasive cut off saw, the experimental investigation shows that the chattering varies with the saw cutting angle due to different compliance. The main work is devoted to finding a desirable cutting angle which reduces the chattering.

A comparison of mesial molar root canal preparations using two engine-driven instruments and the balanced-force technique.

PubMed

Imura, N; Kato, A S; Novo, N F; Hata, G; Uemura, M; Toda, T

2001-10-01

The purpose of this study was to compare the effects of two engine-driven, nickel-titanium instrument systems with hand files in the final shape of slight and moderately curved canals. A total of 72 mesial roots of extracted human mandibular molars were divided into three groups: ProFile .04 taper, Pow-R rotary systems, and Flex-R hand-filing technique. The roots were mounted and cross-sectioned at two different horizontal levels using a modified Bramante technique. Pre- and postinstrumented cross-sectional roots were imaged, recorded, and computer analyzed. Results showed that, at the middle third, in almost all groups, there was a tendency of cutting more toward the mesial side with only one exception: Pow-R cut more to the distal side (danger zone) (p < 0.02). At the apical third, Flex-R (p < 0.03) and ProFile (0.001) transported to the mesial side (danger zone) when the curvature increased. When the three techniques were compared analyzing each side and considering the two groups of curvature, at the middle third in the moderately curved-canal group, Flex-R cut statistically more than Pow-R toward the lingual side. The other comparisons showed no statistically significant difference. When the techniques were compared in relation with the degree of curvature, in the apical third, ProFile .04 cut statistically more toward the mesial side in the moderately curved canal group than in the slightly curved canal group. The other comparisons showed no statistically significant difference. Canal preparation time was shorter with hand instrumentation (p < .05) in a few instances.

A Set of Blast Marks in Color, Right Side

NASA Image and Video Library

2012-08-09

This cut-out from a color panorama image taken by NASA Curiosity rover shows the effects of the descent stage rocket engines blasting the ground. It comes from the right side of the thumbnail panorama obtained the Mast Camera.

Water absorption tests for measuring permeability of field concrete.

DOT National Transportation Integrated Search

2013-09-01

The research results from CFIRE Project 04-06 were communicated to engineers and researchers in this project. : Specifically, the water absorption of concrete samples (i.e., 2-in. thick, 4-in. diameter discs cut from concrete : cylinders) was found s...

A Set of Blast Marks in Color, Left Side

NASA Image and Video Library

2012-08-09

This cut-out from a color panorama image taken by NASA Curiosity rover shows the effects of the descent stage rocket engines blasting the ground. It comes from the left side of the thumbnail panorama obtained by Curiosity Mast Camera.

Ivanishin trims his hair in the Node 3

NASA Image and Video Library

2011-12-18

ISS030-E-012662 (18 Dec. 2011) --- Russian cosmonaut Anatoly Ivanishin, Expedition 30 flight engineer, trims his hair in the Tranquility node of the International Space Station. Ivanishin used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Haircut for Hopkins

NASA Image and Video Library

2013-10-05

ISS037-E-006568 (5 Oct. 2013) --- Russian cosmonaut Fyodor Yurchikhin, Expedition 37 commander, trims the hair of NASA astronaut Michael Hopkins, flight engineer, in the Node 1 module, called Unity. Yurchikhin used hair clippers fashioned with a vacuum device to garner freshly cut hair.

iss019e013266

NASA Image and Video Library

2009-05-03

ISS019-E-013266 (3 May 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 19/20 flight engineer, trims his hair in a crew compartment on the International Space Station, using hair clippers fashioned with a vacuum device to garner freshly cut hair.

Proposed Rule for Repeal of Emission Requirements for Glider Vehicles, Glider Engines, and Glider Kits

EPA Pesticide Factsheets

Rule to finalize standards for medium- and heavy-duty vehicles that would improve fuel efficiency and cut carbon pollution to reduce the impacts of climate change, while bolstering energy security and spurring manufacturing innovation.

Intelligent transportation systems field operational test cross-cutting study : hazardous material incident management

DOT National Transportation Integrated Search

1994-08-01

This handbook was developed to assist design, traffic, and maintenance engineering personnel in making determinations about roadway delineation systems, including the appropriate system for a given situation, when a system has reached the end of its ...

Double patterning from design enablement to verification

NASA Astrophysics Data System (ADS)

Abercrombie, David; Lacour, Pat; El-Sewefy, Omar; Volkov, Alex; Levine, Evgueni; Arb, Kellen; Reid, Chris; Li, Qiao; Ghosh, Pradiptya

2011-11-01

Litho-etch-litho-etch (LELE) is the double patterning (DP) technology of choice for 20 nm contact, via, and lower metal layers. We discuss the unique design and process characteristics of LELE DP, the challenges they present, and various solutions. ∘ We examine DP design methodologies, current DP conflict feedback mechanisms, and how they can help designers identify and resolve conflicts. ∘ In place and route (P&R), the placement engine must now be aware of the assumptions made during IP cell design, and use placement directives provide by the library designer. We examine the new effects DP introduces in detail routing, discuss how multiple choices of LELE and the cut allowances can lead to different solutions, and describe new capabilities required by detail routers and P&R engines. ∘ We discuss why LELE DP cuts and overlaps are critical to optical process correction (OPC), and how a hybrid mechanism of rule and model-based overlap generation can provide a fast and effective solution. ∘ With two litho-etch steps, mask misalignment and image rounding are now verification considerations. We present enhancements to the OPCVerify engine that check for pinching and bridging in the presence of DP overlay errors and acute angles.

Proficiency Standards and Cut-Scores for Language Proficiency Tests.

ERIC Educational Resources Information Center

Moy, Raymond H.

1984-01-01

Discusses the problems associated with "grading on a curve," the approach often used for standard setting on language proficiency tests. Proposes four main steps presented in the setting of a non-arbitrary cut-score. These steps not only establish a proficiency standard checked by external criteria, but also check to see that the test covers the…

Advance reproduction under mature oak stands of the New Jersey coastal plain

Treesearch

John J. Phillips

1963-01-01

In managing hardwood stands, one of the most important tasks is to secure adequate reproduction of desirable species after harvest cuttings. Natural reproduction is usually relied upon. This can be either advance growth (seedlings or seedling sprouts) or reproduction that becomes established after the cutting. Which one the forest manager should mainly rely upon...

Combination of sodium chlorite and calcium propionate reduces enzymatic browning and microbial population of fresh-cut ‘Granny Smith’ apples

USDA-ARS?s Scientific Manuscript database

Tissue browning and microbial growth are the main concerns associated with fresh-cut apples. In this study, effects of sodium chlorite (SC) and calcium propionate (CP), individually and combined, on quality and microbial population of apple slices were investigated. ‘Granny Smith’ apple slices, dipp...

The Effect of Cutting Speed in Metallic Glass Grinding

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

Serbest, Erdinc; Bakkal, Mustafa; Karipcin, Ilker

2011-01-17

In this paper, the effects of the cutting speed in metallic glass grinding were investigated in dry conditions. The results showed that grinding forces decrease as grinding energy increase with the increasing cutting speeds. The present investigations on ground surface and grinding chips morphologies -shows that material removal and surface formation of the BMG are mainly due to the ductile chip deformation and ploughing as well as brittle fracture of some particles from the edges of the tracks. The roughness values obtained with the Cubic Boron Nitride wheels are acceptable for the grinding operation.

Engine systems analysis results of the Space Shuttle Main Engine redesigned powerhead initial engine level testing

NASA Technical Reports Server (NTRS)

Sander, Erik J.; Gosdin, Dennis R.

1992-01-01

Engineers regularly analyze SSME ground test and flight data with respect to engine systems performance. Recently, a redesigned SSME powerhead was introduced to engine-level testing in part to increase engine operational margins through optimization of the engine internal environment. This paper presents an overview of the MSFC personnel engine systems analysis results and conclusions reached from initial engine level testing of the redesigned powerhead, and further redesigns incorporated to eliminate accelerated main injector baffle and main combustion chamber hot gas wall degradation. The conclusions are drawn from instrumented engine ground test data and hardware integrity analysis reports and address initial engine test results with respect to the apparent design change effects on engine system and component operation.

28. Main engine air pump located to port side of ...

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

28. Main engine air pump located to port side of main engine cylinder beside engine bed. Dynamo lies aft of air pump (at right), pipe at extreme left of image carries lake water to condenser valves. - Steamboat TICONDEROGA, Shelburne Museum Route 7, Shelburne, Chittenden County, VT

Chlorine condenser-evaporator simulation

NASA Astrophysics Data System (ADS)

Muraveva, E. A.

2017-10-01

Refrigeration machines are an integral part of chemical engineering. Coldness in mechanical engineering is used to improve the properties of steels, to stabilize the shape and size of steel parts, to restore the dimensions of worn steel hardened parts, to fasten the parts to be machined during cutting and grinding, to ensure fixed planting during assembly, bending pipelines, deep drawing and stamping parts from sheet materials, in the manufacture and processing of rubber parts, with solid anodizing of aluminum alloy parts.

One-step patterning of hollow microstructures in paper by laser cutting to create microfluidic analytical devices.

PubMed

Nie, Jinfang; Liang, Yuanzhi; Zhang, Yun; Le, Shangwang; Li, Dunnan; Zhang, Songbai

2013-01-21

In this paper, we report a simple, low-cost method for rapid, highly reproductive fabrication of paper-based microfluidics by using a commercially available, minitype CO(2) laser cutting/engraving machine. This method involves only one operation of cutting a piece of paper by laser according to a predesigned pattern. The hollow microstructures formed in the paper are used as the 'hydrophobic barriers' to define the hydrophilic flowing paths. A typical paper device on a 4 cm × 4 cm piece of paper can be fabricated within ∼7-20 s; it is ready for use once the cutting process is finished. The main fabrication parameters such as the applied current and cutting rate of the laser were optimized. The fabrication resolution and multiplexed analytical capability of the hollow microstructure-patterned paper were also characterized.

An overview of the current technology relevant to the design and development of the Space Transportation Main Engine (STME)

NASA Technical Reports Server (NTRS)

Das, Digendra K.

1991-01-01

The objective of this project was to review the latest literature relevant to the Space Transportation Main Engine (STME). The search was focused on the following engine components: (1) gas generator; (2) hydrostatic/fluid bearings; (3) seals/clearances; (4) heat exchanges; (5) nozzles; (6) nozzle/main combustion chamber joint; (7) main injector face plate; and (8) rocket engine.

KSC-07pd1271

NASA Image and Video Library

2007-05-24

KENNEDY SPACE CENTER, FLA. -- In Space Shuttle Maine Engine Shop, workers get ready to install an engine controller in one of the three main engines (behind them) of the orbiter Discovery. The controller is an electronics package mounted on each space shuttle main engine. It contains two digital computers and the associated electronics to control all main engine components and operations. The controller is attached to the main combustion chamber by shock-mounted fittings. Discovery is the designated orbiter for mission STS-120 to the International Space Station. It will carry a payload that includes the Node 2 module, named Harmony. Launch is targeted for no earlier than Oct. 20. Photo credit: NASA/Cory Huston

KSC-07pd1272

NASA Image and Video Library

2007-05-24

KENNEDY SPACE CENTER, FLA. -- In the Space Shuttle Maine Engine Shop, workers are installing an engine controller in one of the three main engines of the orbiter Discovery. The controller is an electronics package mounted on each space shuttle main engine. It contains two digital computers and the associated electronics to control all main engine components and operations. The controller is attached to the main combustion chamber by shock-mounted fittings. Discovery is the designated orbiter for mission STS-120 to the International Space Station. It will carry a payload that includes the Node 2 module, named Harmony. Launch is targeted for no earlier than Oct. 20. Photo credit: NASA/Cory Huston

KSC-07pd1274

NASA Image and Video Library

2007-05-24

KENNEDY SPACE CENTER, FLA. -- In the Space Shuttle Maine Engine Shop, workers check the installation of an engine controller in one of the three main engines of the orbiter Discovery. The controller is an electronics package mounted on each space shuttle main engine. It contains two digital computers and the associated electronics to control all main engine components and operations. The controller is attached to the main combustion chamber by shock-mounted fittings. Discovery is the designated orbiter for mission STS-120 to the International Space Station. It will carry a payload that includes the Node 2 module, named Harmony. Launch is targeted for no earlier than Oct. 20. Photo credit: NASA/Cory Huston

KSC-07pd1273

NASA Image and Video Library

2007-05-24

KENNEDY SPACE CENTER, FLA. -- In the Space Shuttle Maine Engine Shop, workers are installing an engine controller in one of the three main engines of the orbiter Discovery. The controller is an electronics package mounted on each space shuttle main engine. It contains two digital computers and the associated electronics to control all main engine components and operations. The controller is attached to the main combustion chamber by shock-mounted fittings. Discovery is the designated orbiter for mission STS-120 to the International Space Station. It will carry a payload that includes the Node 2 module, named Harmony. Launch is targeted for no earlier than Oct. 20. Photo credit: NASA/Cory Huston

KSC-07pd1270

NASA Image and Video Library

2007-05-24

KENNEDY SPACE CENTER, FLA. -- In the Space Shuttle Maine Engine Shop, workers get ready to install an engine controller in one of the three main engines of the orbiter Discovery. The controller is an electronics package mounted on each space shuttle main engine. It contains two digital computers and the associated electronics to control all main engine components and operations. The controller is attached to the main combustion chamber by shock-mounted fittings. Discovery is the designated orbiter for mission STS-120 to the International Space Station. It will carry a payload that includes the Node 2 module, named Harmony. Launch is targeted for no earlier than Oct. 20. Photo credit: NASA/Cory Huston

An improved schlieren method for measurement and automatic reconstruction of the far-field focal spot

PubMed Central

Wang, Zhengzhou; Hu, Bingliang; Yin, Qinye

2017-01-01

The schlieren method of measuring far-field focal spots offers many advantages at the Shenguang III laser facility such as low cost and automatic laser-path collimation. However, current methods of far-field focal spot measurement often suffer from low precision and efficiency when the final focal spot is merged manually, thereby reducing the accuracy of reconstruction. In this paper, we introduce an improved schlieren method to construct the high dynamic-range image of far-field focal spots and improve the reconstruction accuracy and efficiency. First, a detection method based on weak light beam sampling and magnification imaging was designed; images of the main and side lobes of the focused laser irradiance in the far field were obtained using two scientific CCD cameras. Second, using a self-correlation template matching algorithm, a circle the same size as the schlieren ball was dug from the main lobe cutting image and used to change the relative region of the main lobe cutting image within a 100×100 pixel region. The position that had the largest correlation coefficient between the side lobe cutting image and the main lobe cutting image when a circle was dug was identified as the best matching point. Finally, the least squares method was used to fit the center of the side lobe schlieren small ball, and the error was less than 1 pixel. The experimental results show that this method enables the accurate, high-dynamic-range measurement of a far-field focal spot and automatic image reconstruction. Because the best matching point is obtained through image processing rather than traditional reconstruction methods based on manual splicing, this method is less sensitive to the efficiency of focal-spot reconstruction and thus offers better experimental precision. PMID:28207758

Expedition 21 Crew Haircuts

NASA Image and Video Library

2009-11-15

ISS021-E-027120 (15 Nov. 2009) --- NASA astronaut Jeffrey Williams, Expedition 21 flight engineer, trims European Space Agency astronaut Frank De Winne's hair in the Destiny laboratory of the International Space Station. Williams used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Wakata haircut in the Service Module (SM)

NASA Image and Video Library

2009-04-04

ISS018-E-044602 (4 April 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 18/19 flight engineer, trims his hair in the Zarya module of the International Space Station, using scissors and a vacuum device to garner freshly cut hair.

Kuipers trims his hair in the Node 3

NASA Image and Video Library

2011-12-30

ISS030-E-033523 (30 Dec. 2011) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, trims his hair in the Tranquility node of the International Space Station. Kuipers used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Expedition 21 Crew Haircuts

NASA Image and Video Library

2009-11-15

ISS021-E-027106 (15 Nov. 2009) --- NASA astronaut Jeffrey Williams, Expedition 21 flight engineer, trims Canadian Space Agency astronaut Robert Thirsk's hair in the Destiny laboratory of the International Space Station. Williams used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Expedition 21 Crew Haircuts

NASA Image and Video Library

2009-11-15

ISS021-E-027108 (15 Nov. 2009) --- NASA astronaut Jeffrey Williams, Expedition 21 flight engineer, trims Canadian Space Agency astronaut Robert Thirsk's hair in the Destiny laboratory of the International Space Station. Williams used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Haircut for Hopkins

NASA Image and Video Library

2013-10-05

ISS037-E-006571 (5 Oct. 2013) --- Russian cosmonaut Fyodor Yurchikhin, Expedition 37 commander, trims the hair of NASA astronaut Michael Hopkins, flight engineer, in the Unity node of the International Space Station. Yurchikhin used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Haircut for Hopkins

NASA Image and Video Library

2013-10-05

ISS037-E-006565 (5 Oct. 2013) --- Russian cosmonaut Fyodor Yurchikhin, Expedition 37 commander, trims the hair of NASA astronaut Michael Hopkins, flight engineer, in the Unity node of the International Space Station. Yurchikhin used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Kuipers trims his hair in the Node 3

NASA Image and Video Library

2011-12-30

ISS030-E-033548 (30 Dec. 2011) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, trims his hair in the Tranquility node of the International Space Station. Kuipers used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Advanced Space Flight and Environmental Concerns

NASA Technical Reports Server (NTRS)

Whitaker, A.

2001-01-01

The aerospace industry has conquered numerous environmental challenges during the last decade. The aerospace industry of today has evolved due in part to the environmental challenges, becoming stronger, more robust, learning to push the limits of technology, materials and manufacturing, and performing cutting edge engineering.

The Anti-Resonance Criterion in Selecting Pick Systems for Fully Operational Cutting Machinery Used in Mining

NASA Astrophysics Data System (ADS)

Cheluszka, Piotr

2017-12-01

This article discusses the issue of selecting a pick system for cutting mining machinery, concerning the reduction of vibrations in the cutting system, particularly in a load-carrying structure at work. Numerical analysis was performed on a telescopic roadheader boom equipped with transverse heads. A frequency range of the boom's free vibrations with a set structure and dynamic properties were determined based on a dynamic model. The main components excited by boom vibrations, generated through the process of cutting rock, were identified. This was closely associated with the stereometry of the cutting heads. The impact on the pick system (the number of picks and their arrangement along the side of the cutting head) was determined by the intensity of the external boom load elements, especially in resonance zones. In terms of the anti-resonance criterion, an advantageous system of cutting head picks was determined as a result of the analysis undertaken. The correct selection of the pick system was ascertained based on a computer simulation of the dynamic loads and vibrations of a roadheader telescopic boom.

Closeup View of the Space Shuttle Main Engine (SSME) 2044 ...

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

Close-up View of the Space Shuttle Main Engine (SSME) 2044 mounted in a SSME Engine Handler in the SSME processing Facility at Kennedy Space Center. This view shows SSME 2044 with its expansion nozzle removed and an Engine Leak-Test Plug is set in the throat of the Main Combustion Chamber in the approximate center of the image, the insulated, High-Pressure Fuel Turbopump sits below that and the Low Pressure Oxidizer Turbopump Discharge Duct sits towards the top of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Novel tool wear monitoring method in milling difficult-to-machine materials using cutting chip formation

NASA Astrophysics Data System (ADS)

Zhang, P. P.; Guo, Y.; Wang, B.

2017-05-01

The main problems in milling difficult-to-machine materials are the high cutting temperature and rapid tool wear. However it is impossible to investigate tool wear in machining. Tool wear and cutting chip formation are two of the most important representations for machining efficiency and quality. The purpose of this paper is to develop the model of tool wear with cutting chip formation (width of chip and radian of chip) on difficult-to-machine materials. Thereby tool wear is monitored by cutting chip formation. A milling experiment on the machining centre with three sets cutting parameters was performed to obtain chip formation and tool wear. The experimental results show that tool wear increases gradually along with cutting process. In contrast, width of chip and radian of chip decrease. The model is developed by fitting the experimental data and formula transformations. The most of monitored errors of tool wear by the chip formation are less than 10%. The smallest error is 0.2%. Overall errors by the radian of chip are less than the ones by the width of chip. It is new way to monitor and detect tool wear by cutting chip formation in milling difficult-to-machine materials.

Investigation into the Effects of Textural Properties on Cuttability Performance of a Chisel Tool

NASA Astrophysics Data System (ADS)

Tumac, Deniz; Copur, Hanifi; Balci, Cemal; Er, Selman; Avunduk, Emre

2018-04-01

The main objective of this study is to investigate the effect of textural properties of stones on cutting performance of a standard chisel tool. Therewithal, the relationships between textural properties and cutting performance parameters and physical and mechanical properties were statistically analyzed. For this purpose, physical and mechanical property tests and mineralogical and petrographic analyses were carried out on eighteen natural stone samples, which can be grouped into three fundamentally different geological origins, i.e., metamorphic, igneous, and sedimentary. Then, texture coefficient analyses were performed on the samples. To determine the cuttability of the stones; the samples were cut with a portable linear cutting machine using a standard chisel tool at different depths of cut in unrelieved (non-interactive) cutting mode. The average and maximum forces (normal and cutting) and specific energy were measured, and the obtained values were correlated with texture coefficient, packing weighting, and grain size. With reference to the relation between depth of cut and cutting performance of the chisel tool for three types of natural stone groups, specific energy decreases with increasing depth of cut, and cutting forces increase in proportion to the depth of cut. The same is observed for the relationship between packing weighting and both of specific energy and cutter forces. On the other hand, specific energy and the forces decrease while grain size increases. Based on the findings of the present study, texture coefficient has strong correlation with specific energy. Generally, the lower depth of cut values in cutting tests shows higher and more reliable correlations with texture coefficient than the increased depth of cut. The results of cutting tests show also that, at a lower depth of cut (less than 1.5 mm), even stronger correlations can be observed between texture coefficient and cutting performance. Experimental studies indicate that cutting performance of chisel tools can be predicted based on texture coefficients of the natural stones.

Machine Tool Software

NASA Technical Reports Server (NTRS)

1988-01-01

A NASA-developed software package has played a part in technical education of students who major in Mechanical Engineering Technology at William Rainey Harper College. Professor Hack has been using (APT) Automatically Programmed Tool Software since 1969 in his CAD/CAM Computer Aided Design and Manufacturing curriculum. Professor Hack teaches the use of APT programming languages for control of metal cutting machines. Machine tool instructions are geometry definitions written in APT Language to constitute a "part program." The part program is processed by the machine tool. CAD/CAM students go from writing a program to cutting steel in the course of a semester.

Installation Restoration Program. Ohio Air National Guard, Toledo Express Airport, Swanton, Ohio. Site Investigation Work Plan

DTIC Science & Technology

1990-09-01

Initially, cuttings from the borings and wells will be placed on plastic sheeting, covered, and left at the drilling site until a determination can be...Spwmxds Solids (K160.2) X X X X X Nitrate - Nitrate (PE3M.1) X X X X X tPhysical Caracteristics : Soil Enginering Classificatim X X X X X X X X (MQ8-84...site, soil cuttings from drilling the borings and wells will be placed on a plastic tarp and covered until samples of the soil have been screened using

Rejoining of cut wounds by engineered gelatin-keratin glue.

PubMed

Thirupathi Kumara Raja, S; Thiruselvi, T; Sailakshmi, G; Ganesh, S; Gnanamani, A

2013-08-01

Rejoining of cut tissue ends of a critical site challenges clinicians. The toxicity, antigenicity, low adhesive strength, flexibility, swelling and cost of the currently employed glue demands an alternative. Engineered gelatin-keratin glue (EGK-glue) described in the present study was found to be suitable for wet tissue approximation. EGK-glue was prepared by engineering gelatin with caffeic acid using EDC and conjugating with keratin by periodate oxidation. UV-visible, (1)H NMR and circular dichroism analyses followed by experiments on gelation time, rheology, gel adhesive strength (in vitro), wet tissue approximation (in vivo), H&E staining of tissue sections at scheduled time intervals and tensile strength of the healed skin were carried out to assess the effectiveness of the EGK-glue in comparison with fibrin glue and cyanoacrylate. Results of UV-visible, NMR and CD analyses confirmed the functionalization and secondary structural changes. Increasing concentration of keratin reduces the gelation time (<15s). Lap-shear test demonstrates the maximum adhesive strength of 16.6±1.2kPa. Results of hemocompatibility and cytocompatibility studies suggested the suitability of the glue for clinical applications. Tissue approximation property assessed using the incision wound model (Wistar strain) in comparison with cyanoacrylate and fibrin glue suggested, that EGK-glue explicitly accelerates the rejoining of tissue with a 1.86 fold increase in skin tensile strength after healing. Imparting quinone moiety to gelatin-keratin conjugates through caffeic acid and a weaker oxidizing agent provides an adhesive glue with appreciable strength, and hemocompatible, cytocompatible and biodegradable properties, which, rejoin the cut tissue ends effectively. EGK-glue obtained in the present study finds wide biomedical/clinical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

General view of a Space Shuttle Main Engine (SSME) mounted ...

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

General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Fuel Turbopump Discharge Duct looping around the right side and underneath the assembly, the High-Pressure Fuel Turbopump located on the lower left portion of the assembly, the Engine Controller and Main Fuel Valve Hydraulic Actuator located on the upper portion of the assembly and the Low-Pressure Oxidizer Turbopump Discharge Duct at the top of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Anticipatory postural adjustments during cutting manoeuvres in football and their consequences for knee injury risk.

PubMed

Mornieux, Guillaume; Gehring, Dominic; Fürst, Patrick; Gollhofer, Albert

2014-01-01

Anticipatory postural adjustments (APAs), i.e. preparatory positioning of the head, the trunk and the foot, are essential to initiate cutting manoeuvres during football games. The aim of the present study was to determine how APA strategies during cutting manoeuvres are influenced by a reduction of the time available to prepare the movement. Thirteen football players performed different cutting tasks, with directions of cutting either known prior to the task or indicated by a light signal occurring 850, 600 or 500 ms before ground contact. With less time available to prepare the cutting manoeuvre, the head was less orientated towards the cutting direction (P = 0.033) and the trunk was even more rotated in the opposite direction (P = 0.002), while the foot placement was not significantly influenced. Moreover, the induced higher lateral trunk flexion correlated with the increased knee abduction moment (r = 0.41; P = 0.009). Increasing lateral trunk flexion is the main strategy used to successfully perform a cutting manoeuvre when less time is available to prepare the movement. However, higher lateral trunk flexion was associated with an increased knee abduction moment and therefore an increased knee injury risk. Reducing lateral trunk flexion during cutting manoeuvres should be part of training programs seeking the optimisation of APAs.

Plywood Inlays Thourgh CO2 Laser Cutting

NASA Astrophysics Data System (ADS)

Pires, Margarida C.; Araujo, J. L.; Teixeira, M. Ribau; Rodrigues, F. Carvalho

1989-07-01

Furniture with inlays is rather expensive. This is so on two accounts: Firstly, furniture with inlays is generally manufactured with solid wood.Secondly,wood carving and figure cutting are both time consuming and they produce a high rate of rejections. To add to it all the cutting and carving of minute figures requires an outstanding craftmanship. In fact the craftman is in most instance the artist and also the manufacturer. While desiring that the high artistic level is maintained in the industry the search for new method to produce inlays for furniture in not son expensive materials and to produce them in a repetitive and flexible way laser cutting of plywood was found to be quite suitable. This paper presents the charts for CO2 laser cutting of both positive and negatives in several types of plywood. The main problem is not so much the cutting of the positive and negatives pieces but to be able to cut the piece in a way that the fitting is done without any problems caused by the ever present charring effect, which takes palce at the edges of the cut pieces. To minimise this aspect positive and negative pieces have to be cut under stringent focusing conditions and with slight different scales. The condittions for our machine are presented.

Experimental investigation of various surface integrity aspects in hard turning of AISI 4340 alloy steel with coated and uncoated cermet

NASA Astrophysics Data System (ADS)

Das, Anshuman; Patel, S. K.; Sateesh Kumar, Ch.; Biswal, B. B.

2018-03-01

The newer technological developments are exerting immense pressure on domain of production. These fabrication industries are busy finding solutions to reduce the costs of cutting materials, enhance the machined parts quality and testing different materials, which can be made versatile for cutting materials, which are difficult for machining. High-speed machining has been the domain of paramount importance for mechanical engineering. In this study, the variation of surface integrity parameters of hardened AISI 4340 alloy steel was analyzed. The surface integrity parameters like surface roughness, micro hardness, machined surface morphology and white layer of hardened AISI 4340 alloy steel were compared using coated and uncoated cermet inserts under dry cutting condition. From the results, it was deduced that coated insert outperformed uncoated one in terms of different surface integrity characteristics.

Results of small woodlot cuttings on Penobscot Experimental Forest, 1953 and 1954

Treesearch

Arthur C. Hart

1956-01-01

In 1951 foresters at the Penobscot Experimental Forest near Bangor, Maine, began a demonstration of the financial returns that can be realized through careful management of small forest properties. Light improvement cuts made in 1951 and 1952 on a moderately stocked 47-acre tract (Compartment 2) yielded gross incomes of $623.74 and $191.81 respectively. Another well-...

Fuels planning: science synthesis and integration; economic uses fact sheet 02: log hauling cost

Treesearch

Rocky Mountain Research Station USDA Forest Service

2004-01-01

Knowing the cost of fuel reduction treatments and associated activities, such as hauling cut trees, is essential for fire and fuels planning. This fact sheet explores the main factors that determine the cost of hauling cut trees and points the user to an interactive tool that can help plan for those and other expenses.

'Intelligent' system's cost-cutting power.

PubMed

Dodge, Jeremy

2010-05-01

Jeremy Dodge, business manager at Marshall Tufflex Energy Management, explains how a voltage optimisation system that, in a claimed industry first, uses "auto-transformers" to reduce incoming mains electricity voltage so that electrical equipment receives precisely the "outgoing feed" it needs to function optimally and no more, thus significantly reducing wastage, can help major electricity users cut their bills "by as much as 25%".

Structural specificity of Rn nuclease I as probed on yeast tRNA(Phe) and tRNA(Asp).

PubMed Central

Przykorska, A; el Adlouni, C; Keith, G; Szarkowski, J W; Dirheimer, G

1992-01-01

A single-strand-specific nuclease from rye germ (Rn nuclease I) was characterized as a tool for secondary and tertiary structure investigation of RNAs. To test the procedure, yeast tRNA(Phe) and tRNA(Asp) for which the tertiary structures are known, as well as the 3'-half of tRNA(Asp) were used as substrates. In tRNA(Phe) the nuclease introduced main primary cuts at positions U33 and A35 of the anticodon loop and G18 and G19 of the D loop. No primary cuts were observed within the double stranded stems. In tRNA(Asp) the main cuts occurred at positions U33, G34, U35, C36 of the anticodon loop and G18 and C20:1 positions in the D loop. No cuts were observed in the T loop in intact tRNA(Asp) but strong primary cleavages occurred at positions psi 55, C56, A57 within that loop in the absence of the tertiary interactions between T and D loops (use of 3'-half tRNA(Asp)). These results show that Rn nuclease I is specific for exposed single-stranded regions. Images PMID:1542562

Investigations on the potential of a low power diode pumped Er:YAG laser system for oral surgery

NASA Astrophysics Data System (ADS)

Stock, Karl; Wurm, Holger; Hausladen, Florian; Wagner, Sophia; Hibst, Raimund

2015-02-01

Flash lamp pumped Er:YAG-lasers are used in clinical practice for dental applications successfully. As an alternative, several diode pumped Er:YAG laser systems (Pantec Engineering AG) become available, with mean laser power of 2W, 15W, and 30W. The aim of the presented study is to investigate the potential of the 2W Er:YAG laser system for oral surgery. At first an appropriate experimental set-up was realized with a beam delivery and both, a focusing unit for non-contact tissue cutting and a fiber tip for tissue cutting in contact mode. In order to produce reproducible cuts, the samples (porcine gingiva) were moved by a computer controlled translation stage. On the fresh samples cutting depth and quality were determined by light microscopy. Afterwards histological sections were prepared and microscopically analyzed regarding cutting depth and thermal damage zone. The experiments show that low laser power ≤ 2W is sufficient to perform efficient oral soft tissue cutting with cut depth up to 2mm (sample movement 2mm/s). The width of the thermal damage zone can be controlled by the irradiation parameters within a range of about 50μm to 110μm. In general, thermal injury is more pronounced using fiber tips in contact mode compared to the focused laser beam. In conclusion the results reveal that even the low power diode pumped Er:YAG laser is an appropriate tool for oral surgery.

Stennis group receives NESC award

NASA Image and Video Library

2009-04-14

The NASA Engineering & Safety Center recently presented its Group Achievement Award to a Stennis team in recognition of technical excellence in evaluating the operational anomalies and reliability improvements associated with the space shuttle engine cut-off system. Stennis employees receiving the award were: (standing, l to r) Freddie Douglas (NASA), George Drouant (Jacobs Technology Inc.), Fred Abell (Jacobs), Robert Drackett (Jacobs) and Mike Smiles (NASA); (seated, l to r): Binh Nguyen (Jacobs), Stennis Director Gene Goldman and Joseph Lacker (NASA). Phillip Hebert of NASA is not pictured.

Stennis group receives NESC award

NASA Technical Reports Server (NTRS)

2009-01-01

The NASA Engineering & Safety Center recently presented its Group Achievement Award to a Stennis team in recognition of technical excellence in evaluating the operational anomalies and reliability improvements associated with the space shuttle engine cut-off system. Stennis employees receiving the award were: (standing, l to r) Freddie Douglas (NASA), George Drouant (Jacobs Technology Inc.), Fred Abell (Jacobs), Robert Drackett (Jacobs) and Mike Smiles (NASA); (seated, l to r): Binh Nguyen (Jacobs), Stennis Director Gene Goldman and Joseph Lacker (NASA). Phillip Hebert of NASA is not pictured.

New Engineering Solutions in Creation of Mini-BOF for Metallic Waste Recycling

NASA Astrophysics Data System (ADS)

Eronko, S. P.; Gorbatyuk, S. M.; Oshovskaya, E. V.; Starodubtsev, B. I.

2017-12-01

New engineering solutions used in design of the mini melting unit capable of recycling industrial and domestic metallic waste with high content of harmful impurities are provided. High efficiency of the process technology implemented with its use is achieved due to the possibility of the heat and mass transfer intensification in the molten metal bath, controlled charge into it of large amounts of reagents in lumps and in fines, and cut-off of remaining process slag during metal tapping into the teeming ladle.

Robot based deposition of WC-Co HVOF coatings on HSS cutting tools as a substitution for solid cemented carbide cutting tools

NASA Astrophysics Data System (ADS)

Tillmann, W.; Schaak, C.; Biermann, D.; Aßmuth, R.; Goeke, S.

2017-03-01

Cemented carbide (hard metal) cutting tools are the first choice to machine hard materials or to conduct high performance cutting processes. Main advantages of cemented carbide cutting tools are their high wear resistance (hardness) and good high temperature strength. In contrast, cemented carbide cutting tools are characterized by a low toughness and generate higher production costs, especially due to limited resources. Usually, cemented carbide cutting tools are produced by means of powder metallurgical processes. Compared to conventional manufacturing routes, these processes are more expensive and only a limited number of geometries can be realized. Furthermore, post-processing and preparing the cutting edges in order to achieve high performance tools is often required. In the present paper, an alternative method to substitute solid cemented carbide cutting tools is presented. Cutting tools made of conventional high speed steels (HSS) were coated with thick WC-Co (88/12) layers by means of thermal spraying (HVOF). The challenge is to obtain a dense, homogenous, and near-net-shape coating on the flanks and the cutting edge. For this purpose, different coating strategies were realized using an industrial robot. The coating properties were subsequently investigated. After this initial step, the surfaces of the cutting tools were ground and selected cutting edges were prepared by means of wet abrasive jet machining to achieve a smooth and round micro shape. Machining tests were conducted with these coated, ground and prepared cutting tools. The occurring wear phenomena were analyzed and compared to conventional HSS cutting tools. Overall, the results of the experiments proved that the coating withstands mechanical stresses during machining. In the conducted experiments, the coated cutting tools showed less wear than conventional HSS cutting tools. With respect to the initial wear resistance, additional benefits can be obtained by preparing the cutting edge by means of wet abrasive jet machining.

The membrane may be an important factor in browning of fresh-cut pear.

PubMed

Li, Zhenghong; Zhang, Yuxing; Ge, Huibo

2017-09-01

Surface browning is an important cause of deterioration of fresh-cut fruit during postharvest handling. In this paper, four pear cultivars with different extents of natural browning were selected to analyse the factors involved in browning. The main results are as follows: the lipoxygenase (LOX) activity of 'Mantianhong' and 'Yali' pears was higher accompanied by a stronger degree of browning, while the LOX activity in 'Xueqing' and 'Xinli 7' pears was lower, with less browning. A higher unsaturated fatty acid ratio of pear resulted in reduced browning. The cell membranes disappeared 30min after being cut in 'Mantianhong' pear, which browns easily; however, the cell membranes were still intact 30min after being cut in 'Xueqing' pear, which does not brown easily. Therefore, it can be assumed that the stability of the cell membrane plays an important role in inhibiting browning of fresh-cut pears. Copyright © 2017. Published by Elsevier Ltd.

[The behavior of fiber-reinforced plastics during laser cutting].

PubMed

Emmrich, M; Levsen, K; Trasser, F J

1992-06-01

The pattern of the organic emissions, which are produced by processing of fibre reinforced plastics (epoxy resins reinforced by aramid and glass fibres and phenol resins reinforced by aramid fibre) with laser beam was studied and the concentrations of the main components determined. Despite the application of plastic materials with different chemical structures, the observed patterns are very similar. Mainly aromatic hydrocarbons are emitted, especially benzene and toluene, as well as some heteroatom-containing aromatic hydrocarbons (e.g. phenol). By use of oxygen as process gas the emissions during cutting of glass fibre reinforced plastics can be reduced, while they will be constantly high with aramid fibre reinforced plastics.

Wakata haircut in the Service Module (SM)

NASA Image and Video Library

2009-04-04

ISS018-E-044596 (4 April 2009) --- Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, Expedition 18/19 flight engineer, trims his hair in the Zarya module of the International Space Station, using hair clippers fashioned with a vacuum device to garner freshly cut hair.

iss028e035074

NASA Image and Video Library

2011-08-27

ISS028-E-035074 (27 Aug. 2011) --- NASA astronaut Mike Fossum, Expedition 28 flight engineer, trims the hair of Japan Aerospace Exploration Agency astronaut Satoshi Furukawa in the Tranquility node of the International Space Station. Fossum used hair clippers fashioned with a vacuum device to garner freshly cut hair.

iss028e035073

NASA Image and Video Library

2011-08-27

ISS028-E-035073 (27 Aug. 2011) --- NASA astronaut Mike Fossum, Expedition 28 flight engineer, trims the hair of Japan Aerospace Exploration Agency astronaut Satoshi Furukawa in the Tranquility node of the International Space Station. Fossum used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Creamer gives Skvortsov a Haircut in Node 2

NASA Image and Video Library

2010-05-09

ISS023-E-036484 (9 May 2010) --- NASA astronaut T.J. Creamer, Expedition 23 flight engineer, trims Russian cosmonaut Alexander Skvortsov's hair in the Harmony node of the International Space Station. Creamer used hair clippers fashioned with a vacuum device to garner freshly cut hair.

iss028e035071

NASA Image and Video Library

2011-08-27

ISS028-E-035071 (27 Aug. 2011) --- NASA astronaut Mike Fossum, Expedition 28 flight engineer, trims the hair of Japan Aerospace Exploration Agency astronaut Satoshi Furukawa in the Tranquility node of the International Space Station. Fossum used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Creamer gives Skvortsov a Haircut in Node 2

NASA Image and Video Library

2010-05-09

ISS023-E-036485 (9 May 2010) --- NASA astronaut T.J. Creamer, Expedition 23 flight engineer, trims Russian cosmonaut Alexander Skvortsov's hair in the Harmony node of the International Space Station. Creamer used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Prediction of channel degradation rates in urbanizing watersheds

USDA-ARS?s Scientific Manuscript database

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

Featherweight Challenge

ERIC Educational Resources Information Center

Love, Tyler S.; Ryan, Larry

2012-01-01

As science, technology education, and engineering programs suffer budget cuts, educators continue to seek cost-effective activities that engage students and reinforce standards. The featherweight challenge is a hands-on activity that challenges students to continually refine their design while not breaking the budget. This activity uses one of the…

Future Directions in Distance Learning and Communication Technologies

ERIC Educational Resources Information Center

Shih, Timothy; Hung, Jason

2007-01-01

Future Directions in Distance Learning and Communication Technologies presents theoretical studies and practical solutions for engineers, educational professionals, and graduate students in the research areas of e-learning, distance education, and instructional design. This book provides readers with cutting-edge solutions and research directions…

Today's Apprentices, Tomorrow's Leaders.

ERIC Educational Resources Information Center

Tuholski, Robert J.

1982-01-01

Describes an innovative three-year apprenticeship training program in metal cutting tool operation which combines a certification program from the company with an associate in arts degree in applied technology (industrial engineering) from a community college. The combination of hands-on training with theoretical training is explained. (CT)

Driving Pockels Cells Using Avalanche Transistor Pulsers

DTIC Science & Technology

1997-06-01

High Voltage Avalanche Transistor Pulsers", 21st International Power Modulator Symposium, Costa Mesa, CA, June 1994 2 CRC Handbook of Applied ... Engineering Science 200 Edition 1976 Table 7-44 Velocity of Sound in Bar-Shaped Solids Longitudinal Direction Potassium chloride (KCl, sylvite) X-cut 1346

Cutting-edge platforms in cardiac tissue engineering.

PubMed

Fleischer, Sharon; Feiner, Ron; Dvir, Tal

2017-10-01

As cardiac disease takes a higher toll with each passing year, the need for new therapies to deal with the scarcity in heart donors becomes ever more pressing. Cardiac tissue engineering holds the promise of creating functional replacement tissues to repair heart tissue damage. In an attempt to bridge the gap between the lab and clinical realization, the field has made major strides. In this review, we will discuss state of the art technologies such as layer-by-layer assembly, bioprinting and bionic tissue engineering, all developed to overcome some of the major hurdles faced in the field. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metallographic Analysis of Brush Bristle and Integrity Testing of Brush Seal in Shroud Ring of T-700 Engine

NASA Technical Reports Server (NTRS)

Hendricks, Robert C.; Griffin, Thomas A.; Bobula, George A.; Bill, Robert C.; Hull, David R.; Csavina, Kristine R.

1995-01-01

Post-test investigation of a T-700 engine brush seal found regions void of bristles ('yanked out'), regions of bent-over bristles near the inlet, some 'snapped' bristles near the fence, and a more uniform 'smeared' bristle interface between the first and last axial rows of bristles. Several bristles were cut from the brush seal, wax mounted, polished, and analyzed. Metallographic analysis of the bristles near the rub tip showed tungsten-rich phases uniformly distributed throughout the bristle with no apparent change within 1 to 2 micron of the interface except for possibly a small amount of titanium, which would represent a transfer from the rotor. Analysis of the bristle wear face showed nonuniform tungsten, which is indicative of material resolidification. The cut end contained oxides and internal fractures; the worn end was covered with oxide scale. Material losses due to wear and elastoplastic deformation within the shear zone and third-body lubrication effects in the contact zone are discussed.

An Improved Effective Cost Review Process for Value Engineering

PubMed Central

Joo, D. S.; Park, J. I.

2014-01-01

Second-look value engineering (VE) is an approach that aims to lower the costs of products for which target costs are not being met during the production stage. Participants in second-look VE typically come up with a variety of ideas for cost cutting, but the outcomes often depend on their levels of experience, and not many good alternatives are available during the production stage. Nonetheless, good ideas have been consistently generated by VE experts. This paper investigates past second-look VE cases and the thinking processes of VE experts and proposes a cost review process as a systematic means of investigating cost-cutting ideas. This cost review process includes the use of an idea checklist and a specification review process. In addition to presenting the process, this paper reports on its feasibility, based on its introduction into a VE training course as part of a pilot study. The results indicate that the cost review process is effective in generating ideas for later analysis. PMID:25580459

An improved effective cost review process for value engineering.

PubMed

Joo, D S; Park, J I

2014-01-01

Second-look value engineering (VE) is an approach that aims to lower the costs of products for which target costs are not being met during the production stage. Participants in second-look VE typically come up with a variety of ideas for cost cutting, but the outcomes often depend on their levels of experience, and not many good alternatives are available during the production stage. Nonetheless, good ideas have been consistently generated by VE experts. This paper investigates past second-look VE cases and the thinking processes of VE experts and proposes a cost review process as a systematic means of investigating cost-cutting ideas. This cost review process includes the use of an idea checklist and a specification review process. In addition to presenting the process, this paper reports on its feasibility, based on its introduction into a VE training course as part of a pilot study. The results indicate that the cost review process is effective in generating ideas for later analysis.

Some metallographic results for brush bristles and brush segments of a shroud ring brush seal tested in a T-700 engine

NASA Technical Reports Server (NTRS)

Hendricks, Robert C.; Griffin, Thomas A.; Bobula, George A.; Bill, Robert C.; Hull, David R.; Csavina, Kristine R.

1994-01-01

Post-test investigation of a T-700 engine brush seal found regions void of bristles ('yanked out'), regions of bent-over bristles near the inlet, some 'snapped' bristles near the fence, and a more uniform smeared bristle interface between the first and last axial rows of bristles. Several bristles and four brush segments were cut from the brush seal, wax mounted, polished, and analyzed. Metallographic analysis of the bristle near the rub tip showed tungsten-rich phases uniformly distributed throughout the bristle, no apparent change within 1 mu m of the interface, and possibly a small amount of titanium, which would represent a transfer from the rotor. Analysis of the bristle wear face showed nonuniform tungsten, which is indicative of material resolidification. The cut end contained oxides and internal fractures; the worn end was covered with oxide scale. Material losses due to wear and elastoplastic deformation within the shear zone and third-body lubrication effects in the contact zone are discussed.

Skylab

NASA Image and Video Library

1973-05-01

The Saturn V vehicle, carrying the unmarned orbital workshop for the Skylab-1 mission, lifted off successfully and all systems performed normally. Sixty-three seconds into the flight, engineers in the operation support and control center saw an unexpected telemetry indication that signalled that damages occurred on one solar array and the micrometeoroid shield during the launch. The micrometeoroid shield, a thin protective cylinder surrounding the workshop protecting it from tiny space particles and the sun's scorching heat, ripped loose from its position around the workshop. This caused the loss of one solar wing and jammed the other. Still unoccupied, the Skylab was stricken with the loss of the heat shield and sunlight beat mercilessly on the lab's sensitive skin. Intrnal temperatures soared, rendering the station uninhabitable, threatening foods, medicines, films, and experiments. This image shows astronaut Kerwin cutting the metal strap to free and deploy the Orbital Workshop solar array. Kerwin used special cutting tools developed by engineers at the Marshall Space Flight Center (MSFC). The MSFC had a major role in developing the procedures to repair the damaged Skylab.

Complications after LP related to needle type: pencil-point versus Quincke.

PubMed

Aamodt, A; Vedeler, C

2001-06-01

We studied the incidence of complications after diagnostic lumbar puncture (LP) related to needle type. A 5 months' observational study of routine diagnostic LP in 83 patients was conducted. Significantly more headache was observed after LP using thicker cutting needles (20G Quincke) compared with thinner cutting or non-cutting needles (22G Quincke or pencil-point). No significant difference in complications after LP was found between the 22G Quincke and pencil-point needles. The size of the needle and not the needle shape seems to be the main determinant for post-dural puncture headache (PDPH).

Application of dynamic milling in stainless steel processing

NASA Astrophysics Data System (ADS)

Shan, Wenju

2017-09-01

This paper mainly introduces the method of parameter setting for NC programming of stainless steel parts by dynamic milling. Stainless steel is of high plasticity and toughness, serious hard working, large cutting force, high temperature in cutting area and easy wear of tool. It is difficult to process material. Dynamic motion technology is the newest NC programming technology of Mastercam software. It is an advanced machining idea. The tool path generated by the dynamic motion technology is more smooth, more efficient and more stable in the machining process. Dynamic motion technology is very suitable for cutting hard machining materials.

Surface coating metrology of carbides of cutting tools

NASA Astrophysics Data System (ADS)

Parfenov, V. D.; Basova, G. D.

2017-10-01

The coatings were studied by their main sign of the micrometric thickness by means of coating destruction and electron microscopical study of cleavage surfaces. Shock stress ruptures of heated carbides of cutting tools were performed. The discovery of the coating technology and creation of the coating structure for nonuniform and nonequilibrium conditions of the cutting process were dealt with. Multifracture microdestruction of nitride coatings, caused by complex external influences, was analysed to reveal the mechanism of interaction of elementary failures. Positive results were obtained in the form of improving the strength and wear resistance of the product, crack resistance increasing.

Surface and microstructure modifications of Ti-6Al-4V titanium alloy cutting by a water jet/high power laser converging coupling

NASA Astrophysics Data System (ADS)

Weiss, Laurent; Tazibt, Abdel; Aillerie, Michel; Tidu, Albert

2018-01-01

The metallurgical evolution of the Ti-6Al-4V samples is analyzed after an appropriate cutting using a converging water jet/high power laser system. New surface microstructures are obtained on the cutting edge as a result of thermo-mechanical effects of such hybrid fluid-jet-laser tool on the targeted material. The laser beam allows to melt and the water-jet to cool down and to evacuate the material upstream according to a controlled cutting process. The experimental results have shown that a rutile layer can be generated on the surface near the cutting zone. The recorded metallurgical effect is attributed to the chemical reaction between water molecules and titanium, where the laser thermal energy brought onto the surface plays the role of reaction activator. The width of the oxidized zone was found proportional to the cutting speed. During the reaction, hydrogen gas H2 is formed and is absorbed by the metal. The hydrogen atoms trapped into the alloy change the metastable phase formation developing pure β circular grains as a skin at the kerf surface. This result is original so it would lead to innovative converging laser water jet process that could be used to increase the material properties especially for surface treatment, a key value of surface engineering and manufacturing chains.

Automatic OPC repair flow: optimized implementation of the repair recipe

NASA Astrophysics Data System (ADS)

Bahnas, Mohamed; Al-Imam, Mohamed; Word, James

2007-10-01

Virtual manufacturing that is enabled by rapid, accurate, full-chip simulation is a main pillar in achieving successful mask tape-out in the cutting-edge low-k1 lithography. It facilitates detecting printing failures before a costly and time-consuming mask tape-out and wafer print occur. The OPC verification step role is critical at the early production phases of a new process development, since various layout patterns will be suspected that they might to fail or cause performance degradation, and in turn need to be accurately flagged to be fed back to the OPC Engineer for further learning and enhancing in the OPC recipe. At the advanced phases of the process development, there is much less probability of detecting failures but still the OPC Verification step act as the last-line-of-defense for the whole RET implemented work. In recent publication the optimum approach of responding to these detected failures was addressed, and a solution was proposed to repair these defects in an automated methodology and fully integrated and compatible with the main RET/OPC flow. In this paper the authors will present further work and optimizations of this Repair flow. An automated analysis methodology for root causes of the defects and classification of them to cover all possible causes will be discussed. This automated analysis approach will include all the learning experience of the previously highlighted causes and include any new discoveries. Next, according to the automated pre-classification of the defects, application of the appropriate approach of OPC repair (i.e. OPC knob) on each classified defect location can be easily selected, instead of applying all approaches on all locations. This will help in cutting down the runtime of the OPC repair processing and reduce the needed number of iterations to reach the status of zero defects. An output report for existing causes of defects and how the tool handled them will be generated. The report will with help further learning and facilitate the enhancement of the main OPC recipe. Accordingly, the main OPC recipe can be more robust, converging faster and probably in a fewer number of iterations. This knowledge feedback loop is one of the fruitful benefits of the Automatic OPC Repair flow.

An engine awaits processing in the new engine shop at KSC

NASA Technical Reports Server (NTRS)

1998-01-01

In the Space Shuttle Main Engine Processing Facility (SSMEPF), a new Block 2A engine sits on the workstand as technicians process it. The engine is scheduled to fly on the Space Shuttle Endeavour during the STS-88 mission in December 1998. The SSMEPF officially opened on July 6, replacing the Shuttle Main Engine Shop.

Burbank trims Shkaplero's hair in the Node 3

NASA Image and Video Library

2011-12-18

ISS030-E-012660 (18 Dec. 2011) --- NASA astronaut Dan Burbank, Expedition 30 commander, trims the hair of Russian cosmonaut Anton Shkaplerov, flight engineer, in the Tranquility node of the International Space Station. Burbank used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Burbank trims Shkaplerov's hair in the Node 3

NASA Image and Video Library

2012-03-18

ISS030-E-161707 (18 March 2012) --- NASA astronaut Dan Burbank, Expedition 30 commander, trims the hair of Russian cosmonaut Anton Shkaplerov, flight engineer, in the Tranquility node of the International Space Station. Burbank used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Shkaplerov trims Burbank's hair in the Node 3

NASA Image and Video Library

2011-12-18

ISS030-E-012655 (18 Dec. 2011) --- Russian cosmonaut Anton Shkaplerov, Expedition 30 flight engineer, trims the hair of NASA astronaut Dan Burbank, commander, in the Tranquility node of the International Space Station. Shkaplerov used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Whitson gives Tani a haircut in Node 2

NASA Image and Video Library

2007-12-30

ISS016-E-019457 (30 Dec. 2007) --- Astronaut Daniel Tani, Expedition 16 flight engineer, trims his hair in the Harmony node of the International Space Station. Tani used hair clippers fashioned with a vacuum device to garner freshly cut hair. Astronaut Peggy Whitson, commander, assisted Tani.

FACILITY LAYOUT OF FUEL STORAGE BUILDING (CPP603) SHOWING STORAGE BASINS, ...

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

FACILITY LAYOUT OF FUEL STORAGE BUILDING (CPP-603) SHOWING STORAGE BASINS, FUEL ELEMENT CUTTING FACILITY, AND DRY GRAPHITE STORAGE FACILITY. INL DRAWING NUMBER 200-0603-00-030-056329. - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

Final Rule for Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles - Phase 2

EPA Pesticide Factsheets

Rule to finalize standards for medium- and heavy-duty vehicles that would improve fuel efficiency and cut carbon pollution to reduce the impacts of climate change, while bolstering energy security and spurring manufacturing innovation.

A Guide to Energy Savings - For the Dairy Farmers.

ERIC Educational Resources Information Center

Frank, Gary G.

This booklet gives a brief overview of energy use patterns in a dairy farm and gives tips on cutting costs of water heating, ventilation and supplemental heat, milk cooling, vacuum pumps, electric motors, tractors, trucks, engines, and lighting. Finally, energy use recordkeeping is discussed. (BB)

The influence of cutting speed and cutting initiation location in specimen preparation for the microtensile bond strength test.

PubMed

Abreu, Celina Wanderley; Santosb, Jarbas F; Passos, Sheila Pestana; Michida, Silvia Masae; Takahashi, Fernando Eidi; Bottino, Marco Antonio

2011-06-01

This study evaluated the effect of cutting initiation location and cutting speed on the bond strength between resin cement and feldspathic ceramic. Thirty-six blocks (6.4 x 6.4 x 4.8 mm) of ceramic (Vita VM7) were produced. The ceramic surfaces were etched with 10% hydrofluoric acid gel for 60 s and then silanized. Each ceramic block was placed in a silicon mold with the treated surface exposed. A resin cement (Variolink II) was injected into the mold over the treated surface and polymerized. The resin cement-ceramic blocks were divided into two groups according to experimental conditions: a) cutting initiation location - resin cement, ceramic and interface; and b) cutting speed - 10,000, 15,000, and 20,000 rpm. The specimens were sectioned to achieve non-trimmed bar specimens. The microtensile test was performed in a universal testing machine (1 mm/min). The failure modes were examined using an optical light microscope and SEM. Bond strength results were analyzed using one-way ANOVA and Tukey's test (α = 0.05). Significant influences of cutting speed and initiation location on bond strength (p < 0.05) were observed. The highest mean was achieved for specimens cut at 15,000 rpm at the interface (15.12 ± 5.36 MPa). The lowest means were obtained for specimens cut at the highest cutting speed in resin cement (8.50 ± 3.27 MPa), and cut at the lowest cutting speed in ceramic (8.60 ± 2.65 MPa). All groups showed mainly mixed failure (75% to 100%). The cutting speed and initiation location are important factors that should be considered during specimen preparation for microtensile bond strength testing, as both may influence the bond strength results.

From Agrobacterium to viral vectors: genome modification of plant cells by rare cutting restriction enzymes.

PubMed

Marton, Ira; Honig, Arik; Omid, Ayelet; De Costa, Noam; Marhevka, Elena; Cohen, Barry; Zuker, Amir; Vainstein, Alexander

2013-01-01

Researchers and biotechnologists require methods to accurately modify the genome of higher eukaryotic cells. Such modifications include, but are not limited to, site-specific mutagenesis, site-specific insertion of foreign DNA, and replacement and deletion of native sequences. Accurate genome modifications in plant species have been rather limited, with only a handful of plant species and genes being modified through the use of early genome-editing techniques. The development of rare-cutting restriction enzymes as a tool for the induction of site-specific genomic double-strand breaks and their introduction as a reliable tool for genome modification in animals, animal cells and human cell lines have paved the way for the adaptation of rare-cutting restriction enzymes to genome editing in plant cells. Indeed, the number of plant species and genes which have been successfully edited using zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and engineered homing endonucleases is on the rise. In our review, we discuss the basics of rare-cutting restriction enzyme-mediated genome-editing technology with an emphasis on its application in plant species.

Strategies for single-point diamond machining a large format germanium blazed immersion grating

NASA Astrophysics Data System (ADS)

Montesanti, R. C.; Little, S. L.; Kuzmenko, P. J.; Bixler, J. V.; Jackson, J. L.; Lown, J. G.; Priest, R. E.; Yoxall, B. E.

2016-07-01

A large format germanium immersion grating was flycut with a single-point diamond tool on the Precision Engineering Research Lathe (PERL) at the Lawrence Livermore National Laboratory (LLNL) in November - December 2015. The grating, referred to as 002u, has an area of 59 mm x 67 mm (along-groove and cross-groove directions), line pitch of 88 line/mm, and blaze angle of 32 degree. Based on total groove length, the 002u grating is five times larger than the previous largest grating (ZnSe) cut on PERL, and forty-five times larger than the previous largest germanium grating cut on PERL. The key risks associated with cutting the 002u grating were tool wear and keeping the PERL machine running uninterrupted in a stable machining environment. This paper presents the strategies employed to mitigate these risks, introduces pre-machining of the as-etched grating substrate to produce a smooth, flat, damage-free surface into which the grooves are cut, and reports on trade-offs that drove decisions and experimental results.

Efficient prepreg recycling at low temperatures

NASA Astrophysics Data System (ADS)

Pannkoke, Kord; Oethe, Marcus; Busse, Jürgen

When manufacturing fibre reinforced plastics engineers are still confronted with a lack of experience concerning efficient recycling methods for prepreg cutting waste. Normally, the prepregs are cured and subsequently milled to use them as a filler material for polymers. However, this method is expensive and it is difficult to find applications for the milled FRP. An alternative method to recycle CFRP prepregs will be presented in this paper. Cutting the uncured prepreg waste was done by means of a saw mill which was cooled down to low temperatures. Working temperatures of -30°C are sufficient to harden the uncured resin and to achieve cuttable prepregs. Furthermore, post-curing during the cutting process is avoided with this technique. The result is a `cotton'-like matted structure with random fibre orientation and fibre length distribution. Subsequent curing was done by means of a press and an autoclave, respectively. It will be shown by means of tension and bending tests that low-temperature cutting of uncured prepregs is a way to partly conserve the high valuation of FRP during recycling. Furthermore, it offers possibilities for various applications.

Multiple hydrothermal and metamorphic events in the Kidd Creek volcanogenic massive sulphide deposit, Timmins, Ontario: evidence from tourmalines and chlorites

USGS Publications Warehouse

Slack, J.F.; Coad, P.R.

1989-01-01

The tourmalines and chlorites record a series of multiple hydrothermal and metamorphic events. Paragenetic studies suggest that tourmaline was deposited during several discrete stages of mineralization, as evidence by brecciation and cross-cutting relationships. Most of the tourmalines have two concentric growth zones defined by different colours (green, brown, blue, yellow). Some tourmalines also display pale discordant rims that cross-cut and embay the inner growth zones and polycrystalline, multiple-extinction domains. Late sulphide veinlets (chalcopyrite, pyrrhotite) transect the inner growth zones and pale discordant rims of many crystals. The concentric growth zones are interpreted as primary features developed by the main ore-forming hydrothermal system, whereas the discordant rims, polycrystalline domains, and cross-cutting sulphide veinlets reflect post-ore metamorphic processes. Variations in mineral proportions and mineral chemistry within the deposit mainly depend on fluctuations in temperature, pH, water/rock ratios, and amounts of entrained seawater. -from Authors

A New On-Line Detecting Apparatus of the Residual Chlorine in Disinfectant for Fresh-Cut Vegetables

NASA Astrophysics Data System (ADS)

Hu, Chao; Su, Shu-Qiang; Li, Bao-Guo; Liu, Meng-Fang

With the fast development of modern food and beverage industry, fresh-cut vegetables have wider application than before. During the process of sterilization in fresh-cut vegetables, the concentration of chloric disinfectant is usually so high that the common sensor can't be used directly on the product line. In order to solve this problem, we have invented a new detecting apparatus which could detect high concentration of chloric disinfectant directly. In this paper, the working principle, main monitor indicators, application and technical creations of the on-line apparatus have been discussed, and we also carried on the experimental analysis for its performance. The actual demands in factory could be met when the detecting flux is 2L/min, the dilution ratio is 15 and input amount of the disinfectant is 200ml per time, the max of the detecting deviation achieves ±4.8ppm(mg/L). The main detecting range of residual chlorine is 0~300ppm.

Analysis of the convergence rules of full-range PSD surface error of magnetorheological figuring KDP crystal.

PubMed

Chen, Shaoshan; He, Deyu; Wu, Yi; Chen, Huangfei; Zhang, Zaijing; Chen, Yunlei

2016-10-01

A new non-aqueous and abrasive-free magnetorheological finishing (MRF) method is adopted for processing potassium dihydrogen phosphate (KDP) crystal due to its low hardness, high brittleness, temperature sensitivity, and water solubility. This paper researches the convergence rules of the surface error of an initial single-point diamond turning (SPDT)-finished KDP crystal after MRF polishing. Currently, the SPDT process contains spiral cutting and fly cutting. The main difference of these two processes lies in the morphology of intermediate-frequency turning marks on the surface, which affects the convergence rules. The turning marks after spiral cutting are a series of concentric circles, while the turning marks after fly cutting are a series of parallel big arcs. Polishing results indicate that MRF polishing can only improve the low-frequency errors (L>10  mm) of a spiral-cutting KDP crystal. MRF polishing can improve the full-range surface errors (L>0.01  mm) of a fly-cutting KDP crystal if the polishing process is not done more than two times for single surface. We can conclude a fly-cutting KDP crystal will meet better optical performance after MRF figuring than a spiral-cutting KDP crystal with similar initial surface performance.

Prediction of 3D chip formation in the facing cutting with lathe machine using FEM

NASA Astrophysics Data System (ADS)

Prasetyo, Yudhi; Tauviqirrahman, Mohamad; Rusnaldy

2016-04-01

This paper presents the prediction of the chip formation at the machining process using a lathe machine in a more specific way focusing on facing cutting (face turning). The main purpose is to propose a new approach to predict the chip formation with the variation of the cutting directions i.e., the backward and forward direction. In addition, the interaction between stress analysis and chip formation on cutting process was also investigated. The simulations were conducted using three dimensional (3D) finite element method based on ABAQUS software with aluminum and high speed steel (HSS) as the workpiece and the tool materials, respectively. The simulation result showed that the chip resulted using a backward direction depicts a better formation than that using a conventional (forward) direction.

Optimization of Machining Process Parameters for Surface Roughness of Al-Composites

NASA Astrophysics Data System (ADS)

Sharma, S.

2013-10-01

Metal matrix composites (MMCs) have become a leading material among the various types of composite materials for different applications due to their excellent engineering properties. Among the various types of composites materials, aluminum MMCs have received considerable attention in automobile and aerospace applications. These materials are known as the difficult-to-machine materials because of the hardness and abrasive nature of reinforcement element-like silicon carbide particles. In the present investigation Al-SiC composite was produced by stir casting process. The Brinell hardness of the alloy after SiC addition had increased from 74 ± 2 to 95 ± 5 respectively. The composite was machined using CNC turning center under different machining parameters such as cutting speed (S), feed rate (F), depth of cut (D) and nose radius (R). The effect of machining parameters on surface roughness (Ra) was studied using response surface methodology. Face centered composite design with three levels of each factor was used for surface roughness study of the developed composite. A response surface model for surface roughness was developed in terms of main factors (S, F, D and R) and their significant interactions (SD, SR, FD and FR). The developed model was validated by conducting experiments under different conditions. Further the model was optimized for minimum surface roughness. An error of 3-7 % was observed in the modeled and experimental results. Further, it was fond that the surface roughness of Al-alloy at optimum conditions is lower than that of Al-SiC composite.

Microscopic and molecular studies of the diversity of free-living protozoa in meat-cutting plants.

PubMed

Vaerewijck, Mario J M; Sabbe, Koen; Baré, Julie; Houf, Kurt

2008-09-01

The diversity of free-living protozoa in five meat-cutting plants was determined. Light microscopy after enrichment culturing was combined with sequencing of PCR-amplified, denaturing gradient gel electrophoresis (DGGE)-separated 18S rRNA gene fragments, which was used as a fast screening method. The general results of the survey showed that a protozoan community of amoebae, ciliates, and flagellates was present in all of the plants. Protozoa were detected mainly in floor drains, in standing water on the floor, on soiled bars of cutting tables, on plastic pallets, and in out-of-use hot water knife sanitizers, but they were also detected on surfaces which come into direct contact with meat, such as conveyer belts, working surfaces of cutting tables, and needles of a meat tenderizer. After 7 days of incubation at refrigerator temperature, protozoa were detected in about one-half of the enrichment cultures. Based on microscopic observations, 61 morphospecies were found, and Bodo saltans, Bodo spp., Epistylis spp., Glaucoma scintillans, Petalomonas spp., Prodiscophrya collini, and Vannella sp. were the most frequently encountered identified organisms. Sequencing of DGGE bands resulted in identification of a total of 49 phylotypes, including representatives of the Amoebozoa, Chromalveolata, Excavata, Opisthokonta, and Rhizaria. Sequences of small heterotrophic flagellates were affiliated mainly with the Alveolata (Apicomplexa), Stramenopiles (Chrysophyceae), and Rhizaria (Cercozoa). This survey showed that there is high protozoan species richness in meat-cutting plants and that the species included species related to known hosts of food-borne pathogens.

Contribution of 3D printing to mandibular reconstruction after cancer.

PubMed

Dupret-Bories, A; Vergez, S; Meresse, T; Brouillet, F; Bertrand, G

2018-04-01

Three-dimensional (3D) printing is booming in the medical field. This technology increases the possibilities of personalized treatment for patients, while lowering manufacturing costs. To facilitate mandibular reconstruction with fibula free flap, some companies propose cutting guides obtained by CT-guided moulding. However, these guides are prohibitively expensive (€2,000 to €6,000). Based on a partnership with the CNRS, engineering students and a biomedical company, the authors have developed cutting guides and 3D-printed mandible templates, deliverable in 7days and at a lower cost. The novelty of this project is the speed of product development at a significantly lower price. In this technical note, the authors describe the logistic chain of production of mandible templates and cutting guides, as well as the results obtained. The goal is to allow access to this technology to all patients in the near future. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Capturing Knowledge In Order To Optimize The Cutting Process For Polyethylene Pipes Using Knowledge Models

NASA Astrophysics Data System (ADS)

Rotaru, Ionela Magdalena

2015-09-01

Knowledge management is a powerful instrument. Areas where knowledge - based modelling can be applied are different from business, industry, government to education area. Companies engage in efforts to restructure the database held based on knowledge management principles as they recognize in it a guarantee of models characterized by the fact that they consist only from relevant and sustainable knowledge that can bring value to the companies. The proposed paper presents a theoretical model of what it means optimizing polyethylene pipes, thus bringing to attention two important engineering fields, the one of the metal cutting process and gas industry, who meet in order to optimize the butt fusion welding process - the polyethylene cutting part - of the polyethylene pipes. All approach is shaped on the principles of knowledge management. The study was made in collaboration with companies operating in the field.

Seismic analysis of the frame structure reformed by cutting off column and jacking based on stiffness ratio

NASA Astrophysics Data System (ADS)

Zhao, J. K.; Xu, X. S.

2017-11-01

The cutting off column and jacking technology is a method for increasing story height, which has been widely used and paid much attention in engineering. The stiffness will be changed after the process of cutting off column and jacking, which directly affects the overall seismic performance. It is usually necessary to take seismic strengthening measures to enhance the stiffness. A five story frame structure jacking project in Jinan High-tech Zone was taken as an example, and three finite element models were established which contains the frame model before lifting, after lifting and after strengthening. Based on the stiffness, the dynamic time-history analysis was carried out to research its seismic performance under the EL-Centro seismic wave, the Taft seismic wave and the Tianjin artificial seismic wave. The research can provide some guidance for the design and construction of the entire jack lifting structure.

Effects of cutting parameters and machining environments on surface roughness in hard turning using design of experiment

NASA Astrophysics Data System (ADS)

Mia, Mozammel; Bashir, Mahmood Al; Dhar, Nikhil Ranjan

2016-07-01

Hard turning is gradually replacing the time consuming conventional turning process, which is typically followed by grinding, by producing surface quality compatible to grinding. The hard turned surface roughness depends on the cutting parameters, machining environments and tool insert configurations. In this article the variation of the surface roughness of the produced surfaces with the changes in tool insert configuration, use of coolant and different cutting parameters (cutting speed, feed rate) has been investigated. This investigation was performed in machining AISI 1060 steel, hardened to 56 HRC by heat treatment, using coated carbide inserts under two different machining environments. The depth of cut, fluid pressure and material hardness were kept constant. The Design of Experiment (DOE) was performed to determine the number and combination sets of different cutting parameters. A full factorial analysis has been performed to examine the effect of main factors as well as interaction effect of factors on surface roughness. A statistical analysis of variance (ANOVA) was employed to determine the combined effect of cutting parameters, environment and tool configuration. The result of this analysis reveals that environment has the most significant impact on surface roughness followed by feed rate and tool configuration respectively.

Machines employing a hot gas jet to cut metals and nonmetallic materials

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

Polyaev, V.M.; Aleksandrenkov, V.P.

1995-07-01

The flame-cutting of metals is a basic materials-processing operation performed in the course of machine-building and, in some sectors (shipbuilding, aircraft construction, petrochemicals) it is the most important operation. In addition, this method of cutting remains the main operation performed in the processing of scrap metal. The importance of it has occasioned the development of a wide range of cutting tools within just the last decade. Not surprisingly, VNIIavtogen-mash (the All-Union Scientific Research Institute of Machinery for the Gas Welding and Cutting of Metals) is the leading designer of metal-cutting tools in this country. The problem of efficiently cutting metalsmore » is gaining in importance and will continue to do so in coming years in connection with the conversion of military hardware to other uses, the decommissioning of old and obsolete equipment, and utilization of the enormous reserves of scrap in this country. There will thus be a significant increase in the amounts of existing high-alloy steels, nonferrous metals and their alloys, and composites that require cutting. A wide range of cutters is available for the gas-flame cutting of metals, Liquid fuels based on petroleum products are promising from the viewpoint of energy efficiency and performance. The operation of a new generation of cutters, referred to as thermo-gas jet cutters, is based on the principle of the destructive action of a hot, fast-moving, chemically active jet on the material to be cut.« less

Closeup side view of Space Shuttle Main Engine (SSME) 2059 ...

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

Close-up side view of Space Shuttle Main Engine (SSME) 2059 mounted in a SSME Engine Handler near the Drying Area in the High Bay section of the SSME Processing Facility. The prominent features of the SSME in this view are the hot-gas expansion nozzle extending from the approximate image center toward the image right. The main-engine components extend from the approximate image center toward image right until it meets up with the mount for the SSME Engine Handler. The engine is rotated to a position where the major components in the view are the Low-Pressure Fuel Turbopump Discharge Duct with reflective foil insulation on the upper side of the engine, the Low-Pressure Oxidizer Turbopump and its Discharge Duct on the right side of the engine assembly extending itself down and wrapping under the bottom side of the assembly to the High-Pressure Oxidizer Turbopump pump. The High-Pressure Oxidizer Turbopump Discharge Duct exists the turbopump and extends up to the top side of the assembly where it enters the main oxidizer valve. The sphere on the lower side of the engine assembly is an accumulator that is part of the SSMEs POGO suppression system. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

An engine awaits processing in the new engine shop at KSC

NASA Technical Reports Server (NTRS)

1998-01-01

In the Space Shuttle Main Engine Processing Facility (SSMEPF), a new Block 2A engine sits on the transport cradle before being moved to the workstand. The engine is scheduled to fly on the Space Shuttle Endeavour during the STS-88 mission in December 1998. The SSMEPF officially opened on July 6, replacing the Shuttle Main Engine Shop.

Tool wear of (Ti, Al) N-coated polycrystalline cubic boron nitride compact in cutting of hardened steel

NASA Astrophysics Data System (ADS)

Wada, Tadahiro; Hanyu, Hiroyuki

2017-11-01

Polycrystalline cubic boron nitride compact (cBN) is effective tool material for cutting hardened steel. In addition to coated high speed steel and coated cemented carbide that has long been used for cutting materials, more recently, coated cBN has also been used. In this study, to verify the effectiveness of the (Ti,Al)N-coated cBN, which is formed on the substrate of cBN by the physical vapor deposition method, the hardened steel was turned with the (Ti,Al)N-coated cBN tool at a cutting speed of 3.33, 5.00 m/s, a feed rate of 0.3 mm/rev and a depth of cut of 0.1 mm. Furthermore, the uncoated cBN, which was the substrate of the (Ti,Al)N-coated, was also used. The tool wear of the cBN tools was experimentally investigated. The following results were obtained: (1) The contact area between the rake face and the chip of the (Ti,.Al)N-coated cBN tool was smaller than that of the uncoated cBN tool. (2) The tool wear of the (Ti,Al)N-coated cBN was smaller than that of uncoated cBN. (3) The wear progress of the (Ti,Al)N-coated cBN with the main element phase of the TiCN-Al, was slower than that of the (Ti,Al)N-coated cBN with the main element phase of the TiN-Al. (4) In the case of the high cutting speed of 5.00 m/s, the tool wear of the (Ti,Al)N-coated cBN was also smaller than that of uncoated cBN. The above results clarify that the (Ti,Al)N-coated cBN can be used as a tool material in high feed cutting of hardened steel.

STS-87 crew in LC-39B white room during TCDT

NASA Technical Reports Server (NTRS)

1997-01-01

The crew of the STS-87 mission, scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from pad 39B at Kennedy Space Center (KSC), participates in the Terminal Countdown Demonstration Test (TCDT) at KSC. Standing, from left, Mission Specialist Winston Scott; Backup Payload Specialist Yaroslav Pustovyi, Ph.D., of the National Space Agency of Ukraine (NSAU); Payload Specialist Leonid Kadenyuk of NSAU; Pilot Steven Lindsey; Commander Kevin Kregel; Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Mission Specialist Kalpana Chawla, Ph.D. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

STS-87 crew walkout for TCDT

NASA Technical Reports Server (NTRS)

1997-01-01

The crew of the STS-87 mission, scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from pad 39B at Kennedy Space Center (KSC), participated in the Terminal Countdown Demonstration Test (TCDT) at KSC. Simulating the walk-out from the Operations and Checkout Building before entering a van to take them to the launch pad are (left to right) Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine; Mission Specialist Kalpana Chawla, Ph.D.; Pilot Steve Lindsey; Mission Specialist Winston Scott; Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Commander Kevin Kregel. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

STS-87 M.S. Doi and Chawla and P.S. Kadenyuk in slidewire basket

NASA Technical Reports Server (NTRS)

1997-01-01

The crew of the STS-87 mission, scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from pad 39B at Kennedy Space Center (KSC), participates in the Terminal Countdown Demonstration Test (TCDT) at KSC. Testing a slide wire basket that is part of the pads emergency egress system are, from left, Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan; Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU); and Mission Specialist Kalpana Chawla, Ph.D. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

KSC-07pd3634

NASA Image and Video Library

2007-12-14

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, technicians identify an area on space shuttle Atlantis' external tank that might be cut out if tests prove the need to get to the pass-through wiring associated with the engine cut-off, or ECO, sensor system. The shuttle's planned launches on Dec. 6 and Dec. 9 were postponed because of false readings from the part of the ECO system that monitors the liquid hydrogen section of the tank. The liftoff date from NASA's Kennedy Space Center, Florida, is now targeted for Jan. 10, depending on the resolution of the problem in the fuel sensor system. Photo credit: NASA/Kim Shiflett

Surface grinding of space materials using specially formulated vitrified grinding wheels

NASA Astrophysics Data System (ADS)

Jackson, M. J.; Robinson, G.

2006-04-01

The quantum leap that is expected in the reliability and safety of machined engineering components over the next 20 years, especially in the space industries, will require improvements in the quality of cutting tools if science-based manufacturing is the goal for manufacturing by 2020. Significant improvements have been made in the past 10 years by understanding the properties of vitrified bonding systems used to bond conventional and superabrasive materials in grinding tools. The nature of the bonding system is of paramount importance if next-generation cutting tools are to be used for aerospace materials, especially if they are dressed using laser beams.

Modeling nanostructural surface modifications in metal cutting by an approach of thermodynamic irreversibility: Derivation and experimental validation

NASA Astrophysics Data System (ADS)

Buchkremer, S.; Klocke, F.

2017-01-01

Performance and operational safety of many metal parts in engineering depend on their surface integrity. During metal cutting, large thermomechanical loads and high gradients of the loads concerning time and location act on the surfaces and may yield significant structural material modifications, which alter the surface integrity. In this work, the derivation and validation of a model of nanostructural surface modifications in metal cutting are presented. For the first time in process modeling, initiation and kinetics of these modifications are predicted using a thermodynamic potential, which considers the interdependent developments of plastic work, dissipation, heat conduction and interface energy as well as the associated productions and flows of entropy. The potential is expressed based on the free Helmholtz energy. The irreversible thermodynamic state changes in the workpiece surface are homogenized over the volume in order to bridge the gap between discrete phenomena involved with the initiation and kinetics of dynamic recrystallization and its macroscopic implications for surface integrity. The formulation of the thermodynamic potential is implemented into a finite element model of orthogonal cutting of steel AISI 4140. Close agreement is achieved between predicted nanostructures and those obtained in transmission electron microscopical investigations of specimen produced in cutting experiments.

Improving Legacy Aircraft Systems Through Condition-Based Maintenance: An H-60 Case Study

DTIC Science & Technology

2014-09-01

level functions. These decompositions are equivalent to a detailed design effort in systems engineering. NAMPSOPs have a common architectural structure...Assembly Power Available Spindle Cables No.1 Engine Load Demand Spindle Control Cables Engine Pneumatic Starters Auxiliary Power Unit IRCM FLIR Mission...Analysis Fuel System Main Rotor Head Main Module Main Gear Box Radiator Engine Output Shaft Auxiliary Power Unit Flight Control Cables Tail Landing

Amelioration du design et prediction des vitesses moyennes de sortie de buses a jet coherent pour les procedes de rectification a l'aide de la CFD

NASA Astrophysics Data System (ADS)

St-Pierre, Benoit

In order to produce more efficient jet engines, manufacturers add compressor stages to their new engines and their manufacturing departments must increase their productivity while reducing their costs of operation. The addition of these compressor stages causes an increase in the pressures and temperatures for those components. To address this issue, the engineering departments use highly thermal resistant alloys for their manufacturing, mostly nickel alloys. However, these alloys are very difficult to machine by conventional manufacturing processes. Thus, in order to efficiently machine these alloys, grinding processes, like Continuous Dress Creep Feed (CDCF), are always the best choices. However, the productivity of these processes is mainly limited by the burning marks that may appear on the machined surfaces if too aggressive cutting parameters are selected. A simple solution to this issue consists in improving the design of the existing coherent coolant nozzle so that they can produce an even more coherent coolant jet. Therefore, this research project proposes a method which makes it possible to predict the jet coherency of a given nozzle while also giving the possibility to optimize its design in order to improve its jet coherency and all that while using a commercial CFD software, i.e. FLUENT 6.3. Thus, the proposed method is based on the evolution of the velocity profile provided by FLUENT for a given Webster type nozzle and on the experimental measurement of jet coherency of this one in order to establish a semi-empirical model that links these two results. So, for a given nozzle it is possible to precisely predict the physical opening of the coolant jet that this one will produce by using the opening of the velocity profile provided by FLUENT and the semiempirical model developed in this research. The use of FLUENT fonctions also made it possible to simulate the fluid flow inside the coolant nozzle and to identify the cavitation zones within it in order to decrease its importance by modifying the inside profile geometry. This new design of coolant nozzle is more able to produce a coherent jet as compared to the Webster type design. Moreover, this was verified using the semi-empirical model developed in this research and then validated through experimental tests. Finally, cutting tests were performed to compare Webster type nozzle against the newly proposed coolant nozzle design. The results obtained show that the new concept of coolant nozzle gives an improvement in wheel life of more than 15% while slightly decreasing the power required for a cut and that's while preserving a similar surface finish. Finally, a comparative study between FLUENT and Bernoulli equations for the prediction of the mean velocity at the nozzle exit is carried out. This comparison shows that neglecting the effect of turbulence and cavitations on the coolant flow greatly influences the mean velocity at the nozzle exit.

76 FR 33161 - Installation and Use of Engine Cut-off Switches on Recreational Vessels

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-08

...-off switches as a standard safety feature on propulsion machinery and/or starting controls installed... not most, propulsion machinery and/or starting controls installed on recreational vessels are... new subpart N that would cover propulsion machinery capable of developing static thrust of 115 pounds...

Full road closure for work zone operations, a cross-cutting study : reducing congestion and crashes through full road closure for maintenance and construction.

DOT National Transportation Integrated Search

2003-08-01

The objective of this report is to raise awareness among designers construction engineers, and managers of the applications and benefits of full road closure during rehabilitation and construction activities. Based on interviews with project personne...

NASA and general aviation

NASA Technical Reports Server (NTRS)

Ethell, J. L.

1986-01-01

General aviation remains the single most misunderstood sector of aeronautics in the United States. A detailed look at how general aviation functions and how NASA helps keep it on the cutting edge of technology in airfoils, airframes, commuter travel, environmental concerns, engines, propellers, air traffic control, agricultural development, electronics, and safety is given.

Chamitoff gives Volkov a haircut in the Node 2 during Expedition 17

NASA Image and Video Library

2008-07-20

ISS017-E-011556 (20 July 2008) --- NASA astronaut Greg Chamitoff, Expedition 17 flight engineer, trims Russian Federal Space Agency cosmonaut Sergei Volkov's hair in the Harmony node of the International Space Station. Chamitoff used hair clippers fashioned with a vacuum device to garner freshly cut hair.

View of Expedition 28 Crew Members giving and receiving a haircut in the Node 3

NASA Image and Video Library

2011-07-31

ISS028-E-019487 (31 July 2011) --- NASA astronaut Ron Garan, Expedition 28 flight engineer, trims astronaut Mike Fossum?s hair in the Tranquility node of the International Space Station. Garan used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Tani trims his hair in Node 2

NASA Image and Video Library

2008-02-10

S122-E-007645 (10 Feb. 2008) --- Astronaut Daniel Tani, Expedition 16 flight engineer, trims his hair in the Harmony node of the International Space Station while Space Shuttle Atlantis is docked with the station. Tani used hair clippers fashioned with a vacuum device to garner freshly cut hair.

De Winne received haircut in U.S.Laboratory

NASA Image and Video Library

2009-08-09

ISS020-E-034811 (9 Aug. 2009) --- NASA astronaut Tim Kopra, Expedition 20 flight engineer, trims European Space Agency astronaut Frank De Winne’s hair in the Destiny laboratory of the International Space Station. Kopra used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Tani trims his hair in Node 2

NASA Image and Video Library

2008-02-10

S122-E-007643 (10 Feb. 2008) --- Astronaut Daniel Tani, Expedition 16 flight engineer, trims his hair in the Harmony node of the International Space Station while Space Shuttle Atlantis is docked with the station. Tani used hair clippers fashioned with a vacuum device to garner freshly cut hair.

View of Expedition 21 Crew Members trimming hair in the Destiny Laboratory

NASA Image and Video Library

2009-10-11

ISS021-E-005070 (11 Oct. 2009) --- Russian cosmonaut Roman Romanenko, Expedition 21 flight engineer, trims Russian cosmonaut Maxim Suraev's hair in the Destiny laboratory of the International Space Station. Romanenko used hair clippers fashioned with a vacuum device to garner freshly cut hair.

PLOT PLAN OF FUEL STORAGE BUILDING (CPP603) SHOWING STORAGE BASINS ...

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

PLOT PLAN OF FUEL STORAGE BUILDING (CPP-603) SHOWING STORAGE BASINS AND PROPOSED LOCATION OF FUEL ELEMENT CUTTING FACILITY. INL DRAWING NUMBER 200-0603-00-706-051287. ALTERNATE ID NUMBER CPP-C-1287. - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

Computer Review Can Cut HVAC Energy Use

ERIC Educational Resources Information Center

McClure, Charles J. R.

1974-01-01

A computerized review of construction bidding documents, usually done by a consulting engineer, can reveal how much money it will cost to operate various alternative types of HVAC equipment over a school's lifetime. The review should include a computerized load calculation, energy systems flow diagram, control system analysis, and a computerized…

Not Your Grandparents' Vocational School

ERIC Educational Resources Information Center

Schachter, Ron

2012-01-01

Manufacturing biodiesel fuel, building a geodesic-domed greenhouse, measuring the environmental impact of abandoned industrial canals--these might well fit the mission of cutting-edge companies specializing in green technologies, or they could be part of the curriculum at an institution of advanced science and engineering such as MIT or Cal Tech.…

Open pit mining profit maximization considering selling stage and waste rehabilitation cost

NASA Astrophysics Data System (ADS)

Muttaqin, B. I. A.; Rosyidi, C. N.

2017-11-01

In open pit mining activities, determination of the cut-off grade becomes crucial for the company since the cut-off grade affects how much profit will be earned for the mining company. In this study, we developed a cut-off grade determination mode for the open pit mining industry considering the cost of mining, waste removal (rehabilitation) cost, processing cost, fixed cost, and selling stage cost. The main goal of this study is to develop a model of cut-off grade determination to get the maximum total profit. Secondly, this study is also developed to observe the model of sensitivity based on changes in the cost components. The optimization results show that the models can help mining company managers to determine the optimal cut-off grade and also estimate how much profit that can be earned by the mining company. To illustrate the application of the models, a numerical example and a set of sensitivity analysis are presented. From the results of sensitivity analysis, we conclude that the changes in the sales price greatly affects the optimal cut-off value and the total profit.

The Mixed Processing Models Development Of Thermal Fracture And Laser Ablation On Glass Substrate

NASA Astrophysics Data System (ADS)

Huang, Kuo-Cheng; Wu, Wen-Hong; Tseng, Shih-Feng; Hwang, Chi-Hung

2011-01-01

As the industries of cell phone and LCD TV were vigorously flourishing and the manufacturing requirements for LCD glass substrate were getting higher, the thermal fracture cutting technology (TFCT) has progressively become the main technology for LCD glass substrate cutting. Due to using laser as the heat source, the TFCT has many advantages, such as uniform heating, small heat effect zone, and high cutting speed, smooth cutting surface and low residual stress, etc. Moreover, a general laser ablation processing or traditional diamond wheel cutting does not have the last two advantages. The article presents a mixed processing of glass substrate, which consists of TFCT and laser ablation mechanisms, and how to enhance the cutting speed with little ablation laser energy. In this study, a 10W Nd:YAG laser and a 40W CO2 laser are used as the heat source of TFCT and laser ablation processing, respectively. The result indicates that the speed of the mixed processing is more than twice the speed of TFCT. Furthermore, after the mixed processing, the residual stresses in the glass substrates are also smaller.

The impact of an underground cut-off wall on nutrient dynamics in groundwater in the lower Wang River watershed, China.

PubMed

Kang, Pingping; Xu, Shiguo

2017-03-01

Underground cut-off walls in coastal regions are mainly used to prevent saltwater intrusion, but their impact on nutrient dynamics in groundwater is not clear. In this study, a combined analysis of multiple isotopes ([Formula: see text]) and nitrogen and phosphorus concentrations is used in order to assess the impact of the underground cut-off walls on the nutrient dynamics in groundwater in the lower Wang River watershed, China. Compared with the nitrogen and phosphorus concentrations in groundwater downstream of the underground cut-off walls, high [Formula: see text] and total dissolved nitrogen concentrations and similar concentration levels of [Formula: see text] and total dissolved phosphorus are found in groundwater upstream of the underground cut-off walls. The isotopic data indicated the probable occurrence of denitrification and nitrification processes in groundwater upstream, whereas the fingerprint of these processes was not shown in groundwater downstream. The management of fertilizer application is critical to control nitrogen concentrations in groundwater restricted by the underground cut-off walls.

General view of a Space Shuttle Main Engine (SSME) mounted ...

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

General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Oxidizer Turbopump Discharge Duct looping around the right side of the engine assembly then turning in and connecting to the High-Pressure Oxidizer Turbopump. The sphere in the approximate center of the assembly is the POGO System Accumulator, the Engine Controller is located on the bottom and slightly left of the center of the Engine Assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Probabilistic Evaluation of Anthropogenic Regulations In a Vegetated River Channel Using a Vegetation Dynamics Modeling

NASA Astrophysics Data System (ADS)

Miyamoto, Hitoshi

2015-04-01

Vegetation overgrowth in fluvial floodplains, gravel beds, and sand bars has been a serious engineering problem for riparian management in Japan. From the viewpoints of flood control and ecological conservation, it would be necessary to predict the vegetation dynamics accurately for long-term duration. In this research, we have developed a stochastic model for predicting the vegetation dynamics in fluvial floodplains with emphasis on the interaction with flood impacts. The model consists of the following four components: (i) long-term stochastic behavior of flow discharge, (ii) hydrodynamics in a channel with floodplain vegetation, (iii) variation of riverbed topography, and (iv) vegetation dynamics on floodplains. In the vegetation dynamics model, the flood discharge (i) is stochastically simulated using a filtered Poisson process, one of the conventional approaches in hydrological time-series generation. The component for vegetation dynamics (iv) includes the effects of tree growth, mortality by floods, and infant tree recruitment. Vegetation condition has been observed mainly before and after floods since 2008 at a field site located between 23-24 km from the river mouth in Kako River, Japan. The Kako River has the catchment area of 1,730 km2 and the main channel length of 96 km. This site is one of the vegetation overgrowth sites in the Kako River floodplains. The predominant tree species are willows and bamboos. In the field survey, the position, trunk diameter and height of each tree as well as the riverbed materials were measured after several flood events to investigate their impacts on the floodplain vegetation community. This presentation tries to examine effects of anthropogenic river regulations, i.e., thinning and cutting-down, in the vegetated channel in Kako River by using the vegetation dynamics model. Sensitivity of both the flood water level and the vegetation status in the channel is statistically evaluated in terms of the different cutting-down levels, timings and scales of the thinning, etc., by the Monte Carlo simulation of the model.

The use of water-jetting technology in prostheses revision surgery-first results of parameter studies on bone and bone cement.

PubMed

Honl, M; Rentzsch, R; Müller, G; Brandt, C; Bluhm, A; Hille, E; Louis, H; Morlock, M

2000-01-01

Water-jet cutting techniques have been used in industrial applications for many different materials. Recently these techniques have been developed into a revolutionary cutting tool for soft tissues in visceral surgery. The present study investigates the usage of this cutting technology for the revision surgery of endoprostheses. In the first part of the study, samples of bovine bone and acrylic bone cement (PMMA) were cut using an industrial jet cutting device with pure water. Below 400 bar, only PMMA was cut; above 400 bar, bone was also cut, but only pressures above 800 bar resulted in clinically useful rates of material removal (cut depth 2. 4 mm at 10 mm/min traverse speed). In the second part of the study, the effect of adding biocompatible abrasives to the water in order to reduce the required pressure was investigated, resulting in a significantly higher removal of material. At 600 bar, PMMA was cut 5. 2 mm deep with plain water and 15.2 mm deep with added abrasives. The quality of the cuts was increased by the abrasive. Though there was no clear selectivity between bone and PMMA any more, the rate of material removal at similar pressures was significantly higher for PMMA than for bone (600 bar: 1.6 mm cut depth for bone samples, 15.2 mm for PMMA). The measured cut depths with either method were not influenced by a change of the cutting direction with respect to the main direction of the osteons in the bone. However, a reduction of the jet surface angle (90 degrees to 23 degrees ) resulted for bone in a significantly lower cut depth at 600 bar (plain water: 0.62 mm vs. 0.06 mm; abrasive: 1.61 mm vs. 0.60 mm). The laboratory experiments indicate that abrasive water jets may be suitable for cutting biomaterials like bone and bone cement. Copyright 2000 John Wiley & Sons, Inc.

KENNEDY SPACE CENTER, FLA. - Boeing workers perform a 3D digital scan of the actuator on the table. At left is Dan Clark. At right are Alden Pitard (seated at computer) and John Macke, from Boeing, St. Louis. . There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Boeing workers perform a 3D digital scan of the actuator on the table. At left is Dan Clark. At right are Alden Pitard (seated at computer) and John Macke, from Boeing, St. Louis. . There are two actuators per engine on the Shuttle, one for pitch motion and one for yaw motion. The Space Shuttle Main Engine hydraulic servoactuators are used to gimbal the main engine.

Wave structure and flow amplitude-frequency characteristics in the turbine nozzle lattice in the presence of phase transition

NASA Astrophysics Data System (ADS)

Gribin, V. G.; Gavrilov, I. Yu.; Tishchenko, A. A.; Tishchenko, V. A.; Alekseev, R. A.

2017-05-01

This paper is devoted to the wave structure of a flow at its near- and supersonic velocities in a flat turbine cascade of profiles in the zone of phase transitions. The main task was investigation of the mechanics of interaction of the condensation jump with the adiabatic jumps of packing in a change of the initial condition of the flow. The obtained results are necessary for verification of the calculation models of the moisture-steam flow in the elements of lotic parts of the steam turbines. The experimental tests were made on a stand of the wet steam contour (WSC-2) in the Moscow Power Engineering Institute (MPEI, National Research University) at various initial states of steam in a wide range of Mach numbers. In the investigation of the wave structure, use was made of an instrument based on the Schlieren-method principle. The amplitude-frequency characteristics of the flow was found by measurement of static pressure pulsations by means of the piezo resistive sensors established on a bandage plate along the bevel cut of the cascade. It is shown that appearance of phase transitions in the bevel cut of the nozzle turbine cascade leads to a change in the wave structure of the flow. In case of condensation jump, the system of adiabatic jumps in the bevel cut of the cascade becomes nonstationary, and the amplitude-frequency characteristics of static pressure pulsations are restructured. In this, a change in the frequency pulsations of pressure and amplitude takes place. It is noted that, at near-sonic speeds of the flow and the state of saturation at the input, the low-frequency pulsations of static pressure appear that lead to periodic disappearance of the condensation jump and of the adiabatic jump. As a result, in this mode, the flow discharge variations take place.

Hierarchy curriculum for practical skills training in optics and photonics

NASA Astrophysics Data System (ADS)

Zheng, XiaoDong; Wang, XiaoPing; Liu, Xu; Liu, XiangDong; Lin, YuanFang

2017-08-01

The employers in optical engineering fields hope to recruit students who are capable of applying optical principles to solve engineering problems and have strong laboratory skills. In Zhejiang University, a hierarchy curriculum for practical skill training has been constructed to satisfy this demand. This curriculum includes "Introductive practicum" for freshmen, "Opto-mechanical systems design", "Engineering training", "Electronic system design", "Student research training program (SRTP)", "National University Students' Optical-Science-Technology Competition game", and "Offcampus externship". Without cutting optical theory credit hours, this hierarchy curriculum provides a step-by-step solution to enhance students' practical skills. By following such a hierarchy curriculum, students can smoothly advance from a novice to a qualified professional expert in optics. They will be able to utilize optical engineering tools to design, build, analyze, improve, and test systems, and will be able to work effectively in teams to solve problems in engineering and design.

Pattern detection in forensic case data using graph theory: application to heroin cutting agents.

PubMed

Terrettaz-Zufferey, Anne-Laure; Ratle, Frédéric; Ribaux, Olivier; Esseiva, Pierre; Kanevski, Mikhail

2007-04-11

Pattern recognition techniques can be very useful in forensic sciences to point out to relevant sets of events and potentially encourage an intelligence-led style of policing. In this study, these techniques have been applied to categorical data corresponding to cutting agents found in heroin seizures. An application of graph theoretic methods has been performed, in order to highlight the possible relationships between the location of seizures and co-occurrences of particular heroin cutting agents. An analysis of the co-occurrences to establish several main combinations has been done. Results illustrate the practical potential of mathematical models in forensic data analysis.

National Program for Inspection of Non-Federal Dams. Durepo Brook Dam (ME 00348) Saint John River Basin, Limestone, Maine. Phase I Inspection Report.

DTIC Science & Technology

1981-09-01

EXPOLSED BY THE CUT OFF TRE NCHI ESLAVA - ’’ON SHALL Of THOROIUGHLY CLEANED AND INSPLCTLD BY THE - tNGITIIEk PRIOR TO THE PIACIMENT OF THE CIJYOFF TRENCH...concrete impact basin. A grass lined earth cut emergency spillway is provided adjacent to to the right abutment. A sediment and municipal water storage pool...0 698, METHOD CUT OFF SENCI SPIL LWAY EXCAVATION owC CU R:EPRESENTED BY MATERIl. INITEST PIT TP-5(aZ To a’ oR S:ORROW AREA Re I REPRESE NTED CONS

Locomotive Emission and Engine Idle Reduction Technology Demonstration Project

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

John R. Archer

2005-03-14

In response to a United States Department of Energy (DOE) solicitation, the Maryland Energy Administration (MEA), in partnership with CSX Transportation, Inc. (CSXT), submitted a proposal to DOE to support the demonstration of Auxiliary Power Unit (APU) technology on fifty-six CSXT locomotives. The project purpose was to demonstrate the idle fuel savings, the Nitrous Oxide (NOX) emissions reduction and the noise reduction capabilities of the APU. Fifty-six CSXT Baltimore Division locomotives were equipped with APUs, Engine Run Managers (ERM) and communications equipment to permit GPS tracking and data collection from the locomotives. Throughout the report there is mention of themore » percent time spent in the State of Maryland. The fifty-six locomotives spent most of their time inside the borders of Maryland and some spent all their time inside the state borders. Usually when a locomotive traveled beyond the Maryland State border it was into an adjoining state. They were divided into four groups according to assignment: (1) Power Unit/Switcher Mate units, (2) Remote Control units, (3) SD50 Pusher units and (4) Other units. The primary data of interest were idle data plus the status of the locomotive--stationary or moving. Also collected were main engine off, idling or working. Idle data were collected by county location, by locomotive status (stationary or moving) and type of idle (Idle 1, main engine idling, APU off; Idle 2, main engine off, APU on; Idle 3, main engine off, APU off; Idle 4, main engine idle, APU on). Desirable main engine idle states are main engine off and APU off or main engine off and APU on. Measuring the time the main engine spends in these desirable states versus the total time it could spend in an engine idling state allows the calculation of Percent Idle Management Effectiveness (%IME). IME is the result of the operation of the APU plus the implementation of CSXT's Warm Weather Shutdown Policy. It is difficult to separate the two. The units demonstrated an IME of 64% at stationary idle for the test period. The data collected during calendar year 2004 demonstrated that 707,600 gallons of fuel were saved and 285 tons of NOX were not emitted as a result of idle management in stationary idle, which translates to 12,636 gallons and 5.1 tons of NOx per unit respectively. The noise reduction capabilities of the APU demonstrated that at 150 feet from the locomotive the loaded APU with the main engine shut down generated noise that was only marginally above ambient noise level.« less

First-ever evening public engine test of a Space Shuttle Main Engine

NASA Image and Video Library

2001-04-21

Thousands of people watch the first-ever evening public engine test of a Space Shuttle Main Engine at NASA's John C. Stennis Space Center. The spectacular test marked Stennis Space Center's 20th anniversary celebration of the first Space Shuttle mission.

Section 107 Detailed Project Report. Fort Gaines Channel (Government Cut) at Dauphin Island, Alabama

DTIC Science & Technology

1990-03-01

Engineer District, Mobile AREA &WORK UNIT NUMBERS Plan Dev. Sec., Planning Div., (CESAM-PD-FP)- P. 0. Box 2-288, Mobi,L.3.a6628-OO.....,__ 11I...C’ONTAOLLING OFFICE NAME AND ADDRESS M 2 REPORT DATE US. Army Engineer District, Mobile March 1990 Pian Development Sec., Plan. Div., (CESAM-PD-FP) 13 NUMBER...OF PAGES P- 0. Box 2288, Mobile , AL 36628-0001 162 t4. MONITORING AGENCY NAME & ADORESS(11 different from Controlling Office) 15. SECURITY CLASS. (ol

Litmus paper helps detect potential pancreatoenterostomy leakage.

PubMed

Yamaguchi, K; Chijiwa, K; Shimizu, S; Yokohata, K; Tanaka, M

1998-03-01

Leakage of pancreatoenterostomy remains as a serious and fatal complication after pancreatectomy. Several risk factors have been reported, ie, normal pancreatic parenchyma, small pancreatic duct, a large amount of intraoperative blood loss, management of the cut surface of the pancreas, and the presence of preoperative jaundice. Transected pancreatic ductules on the cut surface of the pancreas that are not drained into the main pancreatic duct after pancreatectomy are one of the risks. The pancreatic juice is alkaline and turns red litmus to blue. In order to detect the transected pancreatic ductules on the cut surface of the pancreas, red litmus paper is applied to the cutting surface of the pancreas after stimulation of secretin. Nondrained, transected pancreatic ductules on the cut surface of the pancreas can be detected as blue spots on the red litmus paper. The corresponding areas to the blue spots can be transfixed with sutures to close the nondrained and transected pancreatic ductules. Litmus paper can be expected to detect pancreatoenterostomy leakage after pancreatectomy.

Study of Tool Wear Mechanisms and Mathematical Modeling of Flank Wear During Machining of Ti Alloy (Ti6Al4V)

NASA Astrophysics Data System (ADS)

Chetan; Narasimhulu, A.; Ghosh, S.; Rao, P. V.

2015-07-01

Machinability of titanium is poor due to its low thermal conductivity and high chemical affinity. Lower thermal conductivity of titanium alloy is undesirable on the part of cutting tool causing extensive tool wear. The main task of this work is to predict the various wear mechanisms involved during machining of Ti alloy (Ti6Al4V) and to formulate an analytical mathematical tool wear model for the same. It has been found from various experiments that adhesive and diffusion wear are the dominating wear during machining of Ti alloy with PVD coated tungsten carbide tool. It is also clear from the experiments that the tool wear increases with the increase in cutting parameters like speed, feed and depth of cut. The wear model was validated by carrying out dry machining of Ti alloy at suitable cutting conditions. It has been found that the wear model is able to predict the flank wear suitably under gentle cutting conditions.

Comprehensive Cross-Training among STEM Disciplines in Geothermal Energy

NASA Astrophysics Data System (ADS)

Nunn, J. A.; Dutrow, B. L.

2012-12-01

One of the foremost areas of sustainability is society's need for energy. The US uses more energy per capita than any other country in the world with most of this energy coming from fossil fuels. With its link to climate change coupled with declining resources, renewable alternatives are being pursued. Given the high demand for energy, it is not a question of if these alternatives will be utilized but when and where. One of the "greenest" of the green technologies is geothermal energy. It is a renewable resource with a small environmental footprint. To educate advanced undergraduate and graduate students from across STEM disciplines in geothermal energy, a series of three distinct but linked and related courses are being developed and taught. Courses are focused on one of the STEM disciplines to provide students with essential discipline-specific knowledge and taught by different faculty members in the departments of geology, petroleum engineering and mathematics. These courses provide the foundation necessary for interdisciplinary research projects. The first course on Geologic Properties and Processes of Geothermal Energy was developed and taught in 2012. The class had an enrollment of 27 students including: 5 undergraduates and 4 graduate students in Geology, 12 undergraduates and two graduate students in Petroleum Engineering, and 4 non-matriculated undergraduate students. The course began with the essentials of heat and mass transfer, a common deficiency for all students, then progressed to the geologic materials of these systems: minerals, rocks and fluids. To provide students with first hand experience, two short research projects were embedded into the course. The first project involved analyses of cuttings from a well-studied geothermal system (Salton Sea, CA). Students were in teams consisting of both engineers and geologists. The first assignment was to identify minerals in the cuttings. They were then provided with XRD patterns for their cuttings to more precisely identify the mineralogy of the cuttings. Based on this data with depth, they were asked to predict an approximate temperature range and calculate various fluid parameters for these conditions. The second research project was completed individually, each student covered aspects of heat transport and geologic materials on a specific geothermal field of their choice, created a poster, and gave a brief oral presentation of the poster similar to what is done at scientific meetings. This not only helped students develop communication skills it also provide the class and the instructors information on the breath and diversity of geothermal projects already underway throughout the world and helped to improve critical thinking skills. Continued integration of our research and graduate training programs in Geology and Geophysics, Petroleum Engineering, and Mathematics will occur in 2012-2013. The Petroleum Engineering course will be offered in the fall semester of 2012 and the Mathematics class in the spring semester of 2013. Providing this three semester sequence of courses across the STEM disciplines promotes comprehensive cross-training among disciplines and provides a template for future directions of teaching sustainability across the disciplines.

An engine awaits processing in the new engine shop at KSC

NASA Technical Reports Server (NTRS)

1998-01-01

A new Block 2A engine awaits processing in the low bay of the Space Shuttle Main Engine Processing Facility (SSMEPF). Officially opened on July 6, the new facility replaces the Shuttle Main Engine Shop. The SSMEPF is an addition to the existing Orbiter Processing Facility Bay 3. The engine is scheduled to fly on the Space Shuttle Endeavour during the STS-88 mission in December 1998.

Commercialising genetically engineered animal biomedical products.

PubMed

Sullivan, Eddie J; Pommer, Jerry; Robl, James M

2008-01-01

Research over the past two decades has increased the quality and quantity of tools available to produce genetically engineered animals. The number of potentially viable biomedical products from genetically engineered animals is increasing. However, moving from cutting-edge research to development and commercialisation of a biomedical product that is useful and wanted by the public has significant challenges. Even early stage development of genetically engineered animal applications requires consideration of many steps, including quality assurance and quality control, risk management, gap analysis, founder animal establishment, cell banking, sourcing of animals and animal-derived material, animal facilities, product collection facilities and processing facilities. These steps are complicated and expensive. Biomedical applications of genetically engineered animals have had some recent successes and many applications are well into development. As researchers consider applications for their findings, having a realistic understanding of the steps involved in the development and commercialisation of a product, produced in genetically engineered animals, is useful in determining the risk of genetic modification to the animal nu. the potential public benefit of the application.

A new device to test cutting efficiency of mechanical endodontic instruments.

PubMed

Giansiracusa Rubini, Alessio; Plotino, Gianluca; Al-Sudani, Dina; Grande, Nicola M; Sonnino, Gianpaolo; Putorti, Ermanno; Cotti, Elisabetta; Testarelli, Luca; Gambarini, Gianluca

2014-03-06

The purpose of the present study was to introduce a new device specifically designed to evaluate the cutting efficiency of mechanically driven endodontic instruments. Twenty new Reciproc R25 (VDW, Munich, Germany) files were used to be investigated in the new device developed to test the cutting ability of endodontic instruments. The device consists of a main frame to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1mm. The instruments were activated by using a torque-controlled motor (Silver Reciproc; VDW, Munich, Germany) in a reciprocating movement by the "Reciproc ALL" program (Group 1) and in counter-clockwise rotation at 300 rpm (Group 2). Mean and standard deviations of each group were calculated and data were statistically analyzed with a one-way ANOVA test (P<0.05). Reciproc in reciprocation (Group 1) mean cut in the Plexiglas block was 8.6 mm (SD=0.6 mm), while Reciproc in rotation mean cut was 8.9 mm (SD=0.7 mm). There was no statistically significant difference between the 2 groups investigated (P>0.05). The cutting testing device evaluated in the present study was reliable and easy to use and may be effectively used to test cutting efficiency of both rotary and reciprocating mechanical endodontic instruments.

Effect of cutting parameters on strain hardening of nickel–titanium shape memory alloy

NASA Astrophysics Data System (ADS)

Wang, Guijie; Liu, Zhanqiang; Ai, Xing; Huang, Weimin; Niu, Jintao

2018-07-01

Nickel–titanium shape memory alloy (SMA) has been widely used as implant materials due to its good biocompatibility, shape memory property and super-elasticity. However, the severe strain hardening is a main challenge due to cutting force and temperature caused by machining. An orthogonal experiment of nickel–titanium SMA with different milling parameters conditions was conducted in this paper. On the one hand, the effect of cutting parameters on work hardening is obtained. It is found that the cutting speed has the most important effect on work hardening. The depth of machining induced layer and the degree of hardening become smaller with the increase of cutting speed when the cutting speed is less than 200 m min‑1 and then get larger with further increase of cutting speed. The relative intensity of diffraction peak increases as the cutting speed increase. In addition, all of the depth of machining induced layer, the degree of hardening and the relative intensity of diffraction peak increase when the feed rate increases. On the other hand, it is found that the depth of machining induced layer is closely related with the degree of hardening and phase transition. The higher the content of austenite in the machined surface is, the higher the degree of hardening will be. The depth of the machining induced layer increases with the degree of hardening increasing.

Multiresponse Optimization of Process Parameters in Turning of GFRP Using TOPSIS Method

PubMed Central

Parida, Arun Kumar; Routara, Bharat Chandra

2014-01-01

Taguchi's design of experiment is utilized to optimize the process parameters in turning operation with dry environment. Three parameters, cutting speed (v), feed (f), and depth of cut (d), with three different levels are taken for the responses like material removal rate (MRR) and surface roughness (R a). The machining is conducted with Taguchi L9 orthogonal array, and based on the S/N analysis, the optimal process parameters for surface roughness and MRR are calculated separately. Considering the larger-the-better approach, optimal process parameters for material removal rate are cutting speed at level 3, feed at level 2, and depth of cut at level 3, that is, v 3-f 2-d 3. Similarly for surface roughness, considering smaller-the-better approach, the optimal process parameters are cutting speed at level 1, feed at level 1, and depth of cut at level 3, that is, v 1-f 1-d 3. Results of the main effects plot indicate that depth of cut is the most influencing parameter for MRR but cutting speed is the most influencing parameter for surface roughness and feed is found to be the least influencing parameter for both the responses. The confirmation test is conducted for both MRR and surface roughness separately. Finally, an attempt has been made to optimize the multiresponses using technique for order preference by similarity to ideal solution (TOPSIS) with Taguchi approach. PMID:27437503

Evaluation of the Kuper-Tuca SX36 snow plow cutting edges.

DOT National Transportation Integrated Search

2010-06-01

For the winter of 2009-2010, the MaineDOT experimented with three sets of the Kuper Tuca SX36 : plow blades. Two of these sets were used in the Region 4, Bangor maintenance facility and one set was : used in the Region 3, Turner facility. : Maine...

5. ENGINE TEST CELL BUILDING INTERIOR. CENTRAL ROOM ON MAIN ...

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

5. ENGINE TEST CELL BUILDING INTERIOR. CENTRAL ROOM ON MAIN FLOOR. LOOKING NORTHWEST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

Study of the Productivity and Surface Quality of Hybrid EDM

NASA Astrophysics Data System (ADS)

Wankhade, Sandeepkumar Haribhau; Sharma, Sunil Bansilal

2016-01-01

The development of new, advanced engineering materials and the need for precise prototypes and low-volume production have made the electric discharge machining (EDM), an important manufacturing process to meet such demands. It is capable of machining geometrically complex and hard material components, that are precise and difficult-to-machine such as heat treated tool steels, composites, super alloys, ceramics, carbides etc. Conversely the low MRR limits its productivity. Abrasive water jet machine (AJM) tools are quick to setup and offer quick turn-around on the machine and could make parts out of virtually any material. They do not heat the material hence no heat affected zone and can make any intricate shape easily. The main advantages are flexibility, low heat production and ability to machine hard and brittle materials. Main disadvantages comprise the process produces a tapered cut and health hazards due to dry abrasives. To overcome the limitations and exploit the best of each of above processes; an attempt has been made to hybridize the processes of AJM and EDM. The appropriate abrasives routed with compressed air through the hollow electrode to construct the hybrid process i.e., abrasive jet electric discharge machining (AJEDM), the high speed abrasives could impinge on the machined surface to remove the recast layer caused by EDM process. The main process parameters were varied to explore their effects and experimental results show that AJEDM enhances the machining efficiency with better surface finish hence can fit the requirements of modern manufacturing applications.

Aft Engine shop worker removes a heat shield on Columbia's main engines

NASA Technical Reports Server (NTRS)

2002-01-01

KENNEDY SPACE CENTER, FLA. -- Doug Buford (top), with the Aft Engine shop, along with another worker, removes a heat shield on one of Columbia's engines. After small cracks were discovered on the LH2 Main Propulsion System (MPS) flow liners in two other orbiters, program managers decided to move forward with inspections on Columbia before clearing it for flight on STS-107. After removal of the heat shields, the three main engines will be removed. Inspections of the flow liners will follow. The July 19 launch of Columbia on STS-107 has been delayed a few weeks

Integration of Centrifuge Testing in Undergraduate Geotechnical Engineering Education at Remote Campuses

ERIC Educational Resources Information Center

El Shamy, Usama; Abdoun, Tarek; McMartin, Flora; Pando, Miguel A.

2013-01-01

We report the results of a pilot study aimed at developing, implementing, and assessing an educational module that integrates remote major research instrumentation into undergraduate classes. Specifically, this study employs Internet Web-based technologies to allow for real-time video monitoring and execution of cutting-edge experiments. The…

New Design Tool Can Help Cut building Energy Use

Science.gov Websites

help almost any architect or engineer evaluate passive solar and efficiency design strategies in a tool that enables them to walk through the design process and understand the consequences of design , a feature that tells designers how large of a heating, ventilation and air conditioning (HVAC

The Electric Power Exhibit Challenge

ERIC Educational Resources Information Center

Roman, Harry T.

2012-01-01

A design challenge is all about planning first and understanding the problem before diving in and looking frantically for a solution. Any experienced engineer or designer will tell one to think first and plan the steps before acting. An experienced carpenter friend of the author always said to "take many measurements and cut once." There is great…

An Online, Interactive Renewable Energy Laboratory

ERIC Educational Resources Information Center

O'Leary, D. A.; Shattuck, J.; Kubby, J.

2012-01-01

An undergraduate introductory science, technology, engineering, and math (STEM) class can be a jarring disappointment to new students expecting to work with cutting-edge, real-world technology. Their cell phones are often more technically advanced and real-world than the tools used in a class lab. Not surprisingly, many complain that the STEM labs…

Florida Polytechnic University Annual Accountability Report, 2013-14

ERIC Educational Resources Information Center

Board of Governors, State University System of Florida, 2014

2014-01-01

Florida Polytechnic University offers industry focused, cutting-edge STEM degree programs in the College of Engineering and the College of Innovation and Technology. As a new university, they have the ability to adapt and be responsive to their industry partners' needs in a timely manner. The curriculum is cross-discipline and includes lab and…

Skills Conversion Project: Chapter 6, Forest Operations and Wood Products. Final Report.

ERIC Educational Resources Information Center

National Society of Professional Engineers, Washington, DC.

A study of the forest operations and wood products industries was conducted in Atlanta and Seattle by the National Society of Professional Engineers. Included among these industries are tree development, crop and land management, logging, material handling transportation, cutting, peeling, assembly, pulp and paper, mobile homes, construction,…

30 CFR 75.1910 - Nonpermissible diesel-powered equipment; electrical system design and performance requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... simultaneously and perform virtually the same duty; (f) Each ungrounded conductor must have insulation compatible with the impressed voltage. Insulation materials must be resistant to deterioration from engine heat... damaging wires, cables, or conduits by cutting or abrasion. The insulation of the cables within a battery...

30 CFR 75.1910 - Nonpermissible diesel-powered equipment; electrical system design and performance requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... simultaneously and perform virtually the same duty; (f) Each ungrounded conductor must have insulation compatible with the impressed voltage. Insulation materials must be resistant to deterioration from engine heat... damaging wires, cables, or conduits by cutting or abrasion. The insulation of the cables within a battery...

30 CFR 75.1910 - Nonpermissible diesel-powered equipment; electrical system design and performance requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... simultaneously and perform virtually the same duty; (f) Each ungrounded conductor must have insulation compatible with the impressed voltage. Insulation materials must be resistant to deterioration from engine heat... damaging wires, cables, or conduits by cutting or abrasion. The insulation of the cables within a battery...

30 CFR 75.1910 - Nonpermissible diesel-powered equipment; electrical system design and performance requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... simultaneously and perform virtually the same duty; (f) Each ungrounded conductor must have insulation compatible with the impressed voltage. Insulation materials must be resistant to deterioration from engine heat... damaging wires, cables, or conduits by cutting or abrasion. The insulation of the cables within a battery...

Coleman cuts Nespoli's hair in the JPM

NASA Image and Video Library

2011-01-15

ISS026-E-017741 (15 Jan. 2011) --- NASA astronaut Catherine (Cady) Coleman assists European Space Agency astronaut Paolo Nespoli with a haircut in the Kibo laboratory on the International Space Station. The two Expedition 26 flight engineers used a vacuum cleaner (partially out of frame) to remove free-floating hair particles from the air.

Coleman cuts Nespoli's hair in the JPM

NASA Image and Video Library

2011-01-15

ISS026-E-017736 (15 Jan. 2011) --- NASA astronaut Catherine (Cady) Coleman assists European Space Agency astronaut Paolo Nespoli with a haircut in the Kibo laboratory on the International Space Station. The two Expedition 26 flight engineers used a vacuum cleaner (partially out of frame) to remove free-floating hair particles from the air.

Nespoli cuts Kondratyev's hair in the JPM

NASA Image and Video Library

2011-01-15

ISS026-E-017715 (15 Jan. 2011) --- European Space Agency astronaut Paolo Nespoli assists cosmonaut Dmitry Kondratyev of Russia's Federal Space Agency (Roscosmos) with a haircut in the Kibo laboratory on the International Space Station. The two Expedition 26 flight engineers used a vacuum cleaner to remove free-floating hair particles from the air.

Coleman cuts Kondratyev's hair in the JPM

NASA Image and Video Library

2011-01-15

ISS026-E-017725 (15 Jan. 2011) --- NASA astronaut Catherine (Cady) Coleman assists cosmonaut Dmitry Kondratyev of Russia's Federal Space Agency (Roscosmos) with a haircut in the Kibo laboratory on the International Space Station. The two Expedition 26 flight engineers used a vacuum cleaner to remove free-floating hair particles from the air.

LPT. Low power test control building (TAN641) interior. Camera facing ...

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

LPT. Low power test control building (TAN-641) interior. Camera facing northeast at what remains of control room console. Cut in wall at right of view shows west wall of northern test cell. INEEL negative no. HD-40-4-4 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Prescribed Burning and Clear-Cutting Effects on Understory Vegetation in a Pinus canariensis Stand (Gran Canaria)

PubMed Central

Arévalo, José Ramón; García-Domínguez, Celia; Naranjo-Cigala, Agustín; Grillo, Federico

2014-01-01

Prescribed fires are a powerful tool for reducing fire hazards by decreasing amounts of fuel. The main objective is to analyze the effects of prescribed burning on the understory vegetation composition as well as on the soil characteristics of a reforested stand of Pinus canariensis. The study attempts to identify the effects of the preburning treatment of cutting understory vegetation on the floristic parameters of the vegetation community. This study was carried out for two years following a prescribed fire in a Canarian pine stand. Cutting and burning treatment affected species composition and increased diversity. Burnt and cut plots were characterized by a diverse array of herbaceous species and by a lower abundance of Teline microphylla (endemic legume), although burning apparently induced its germination. Cut treatment was more consistently differentiated from the control plots than burnt treatment. Soil K decreased after both treatments, pH slightly decreased after cutting, while P and Ca increased after fire. From an ecological point of view, prescribed burning is a better management practice than cutting the woody species of the understory. However, long-term studies would be necessary to evaluate the effects of fire intensity, season and frequency in which the prescribed burning is applied. PMID:25147839

Prescribed burning and clear-cutting effects on understory vegetation in a Pinus canariensis stand (Gran Canaria).

PubMed

Arévalo, José Ramón; Fernández-Lugo, Silvia; García-Domínguez, Celia; Naranjo-Cigala, Agustín; Grillo, Federico; Calvo, Leonor

2014-01-01

Prescribed fires are a powerful tool for reducing fire hazards by decreasing amounts of fuel. The main objective is to analyze the effects of prescribed burning on the understory vegetation composition as well as on the soil characteristics of a reforested stand of Pinus canariensis. The study attempts to identify the effects of the preburning treatment of cutting understory vegetation on the floristic parameters of the vegetation community. This study was carried out for two years following a prescribed fire in a Canarian pine stand. Cutting and burning treatment affected species composition and increased diversity. Burnt and cut plots were characterized by a diverse array of herbaceous species and by a lower abundance of Teline microphylla (endemic legume), although burning apparently induced its germination. Cut treatment was more consistently differentiated from the control plots than burnt treatment. Soil K decreased after both treatments, pH slightly decreased after cutting, while P and Ca increased after fire. From an ecological point of view, prescribed burning is a better management practice than cutting the woody species of the understory. However, long-term studies would be necessary to evaluate the effects of fire intensity, season and frequency in which the prescribed burning is applied.

The ribbon-cutting ceremony unveils the reactivated altitude chamber inside the O&C high bay

NASA Technical Reports Server (NTRS)

1999-01-01

Cutting a red ribbon for the unveiling of a newly renovated altitude chamber are (left to right) Tommy Mack, project manager, NASA; Steve Francois, director, Space Station and Shuttle Payloads; Sterling Walker, director, Engineering Development; Roy Bridges, director, Kennedy Space Center; Jay Greene, International Space Station manager for Technical; Michael Terry, project manager, Boeing; and Terry Smith, director of Engineering, Boeing Space Coast Operations. The chamber was reactivated, after a 24-year hiatus, to perform leak tests on International Space Station pressurized modules at the launch site. Originally, two chambers were built to test the Apollo command and lunar service modules. They were last used in 1975 during the Apollo-Soyuz Test Project. After installation of new vacuum pumping equipment and controls, a new control room, and a new rotation handling fixture, the chamber again became operational in February 1999. The chamber, which is 33 feet in diameter and 50 feet tall, is constructed of stainless steel. The first module that will be tested for leaks is the U.S. Laboratory. No date has been determined for the test.

Use Of Lasers In Seam Welding Of Engine Parts For Cars

NASA Astrophysics Data System (ADS)

Luttke, A.

1986-11-01

The decision in favour of active research into laser technology was taken in our company in 1978. In the following years we started with the setting-up of a laser laboratory charged with the task of performing basic manufacturing technology experiments in order to examine the ap-plications of laser technology for cutting, welding, hardening, remelting and secondary alloys. The first laboratory-laser - a 2,5 kW fast axial flow CO2 laser - is connected with a CNC-controlled workpiece manipulation unit, which is designed in such a way that workpieces from the smallest component of a car gearbox up to crankcases for commercial vehicles can be manipulated at speeds considered theoretically feasible for laser machining. The use of the laser beam for cutting, hardening and welding tasks has been under investigation in our company, in this laboratory for some 6 years. Laser cutting is now no longer a question of development, but is instead standard practice and is already used in various sec-tions of our production division for pilot-series manufacturing and for small batches. Laser hardening has, in our opinion, great possibilities for tasks which, for distortion and accessibility reasons, cannot be satisfactorily performed using present-day processes, for instance induction hardening. However, a great deal of development work is still necessary before economically reasonable and quality-assured production installation can be undertaken. Laser-welding is now used in series-production in our company for two engine components. More details are given below.

Custom-Designed Molecular Scissors for Site-Specific Manipulation of the Plant and Mammalian Genomes

NASA Astrophysics Data System (ADS)

Kandavelou, Karthikeyan; Chandrasegaran, Srinivasan

Zinc finger nucleases (ZFNs) are custom-designed molecular scissors, engineered to cut at specific DNA sequences. ZFNs combine the zinc finger proteins (ZFPs) with the nonspecific cleavage domain of the FokI restriction enzyme. The DNA-binding specificity of ZFNs can be easily altered experimentally. This easy manipulation of the ZFN recognition specificity enables one to deliver a targeted double-strand break (DSB) to a genome. The targeted DSB stimulates local gene targeting by several orders of magnitude at that specific cut site via homologous recombination (HR). Thus, ZFNs have become an important experimental tool to make site-specific and permanent alterations to genomes of not only plants and mammals but also of many other organisms. Engineering of custom ZFNs involves many steps. The first step is to identify a ZFN site at or near the chosen chromosomal target within the genome to which ZFNs will bind and cut. The second step is to design and/or select various ZFP combinations that will bind to the chosen target site with high specificity and affinity. The DNA coding sequence for the designed ZFPs are then assembled by polymerase chain reaction (PCR) using oligonucleotides. The third step is to fuse the ZFP constructs to the FokI cleavage domain. The ZFNs are then expressed as proteins by using the rabbit reticulocyte in vitro transcription/translation system and the protein products assayed for their DNA cleavage specificity.

Machining the Integral Impeller and Blisk of Aero-Engines: A Review of Surface Finishing and Strengthening Technologies

NASA Astrophysics Data System (ADS)

Fu, Youzhi; Gao, Hang; Wang, Xuanping; Guo, Dongming

2017-05-01

The integral impeller and blisk of an aero-engine are high performance parts with complex structure and made of difficult-to-cut materials. The blade surfaces of the integral impeller and blisk are functional surfaces for power transmission, and their surface integrity has significant effects on the aerodynamic efficiency and service life of an aero-engine. Thus, it is indispensable to finish and strengthen the blades before use. This paper presents a comprehensive literature review of studies on finishing and strengthening technologies for the impeller and blisk of aero-engines. The review includes independent and integrated finishing and strengthening technologies and discusses advanced rotational abrasive flow machining with back-pressure used for finishing the integral impeller and blisk. A brief assessment of future research problems and directions is also presented.

Engineering Cellular Metabolism.

PubMed

Nielsen, Jens; Keasling, Jay D

2016-03-10

Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds, and pharmaceuticals. However, making cells into efficient factories is challenging because cells have evolved robust metabolic networks with hard-wired, tightly regulated lines of communication between molecular pathways that resist efforts to divert resources. Here, we will review the current status and challenges of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation. Copyright © 2016 Elsevier Inc. All rights reserved.

General view of a Space Shuttle Main Engine (SSME) mounted ...

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

General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Fuel Turbopump Discharge Duct looping diagonally across the top of the assembly and connecting to the High-Pressure Fuel Turbopump, the Low-Pressure Oxidizer Turbopump (LPOTP) located center right of the assembly and the LPOTP Discharge Duct looping around from the pump to the underside of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

High-Temperature Smart Structures for Engine Noise Reduction and Performance Enhancement

NASA Technical Reports Server (NTRS)

Quackenbush, Todd R.; McKillip, Robert M., Jr.

2011-01-01

One of key NASA goals is to develop and integrate noise reduction technology to enable unrestricted air transportation service to all communities. One of the technical priorities of this activity has been to account for and reduce noise via propulsion/airframe interactions, identifying advanced concepts to be integrated with the airframe to mitigate these noise-producing mechanisms. An adaptive geometry chevron using embedded smart structures technology offers the possibility of maximizing engine performance while retaining and possibly enhancing the favorable noise characteristics of current designs. New high-temperature shape memory alloy (HTSMA) materials technology enables the devices to operate in both low-temperature (fan) and high-temperature (core) exhaust flows. Chevron-equipped engines have demonstrated reduced noise in testing and operational use. It is desirable to have the noise benefits of chevrons in takeoff/landing conditions, but have them deployed into a minimum drag position for cruise flight. The central feature of the innovation was building on rapidly maturing HTSMA technology to implement a next-generation aircraft noise mitigation system centered on adaptive chevron flow control surfaces. In general, SMA-actuated devices have the potential to enhance the demonstrated noise reduction effectiveness of chevron systems while eliminating the associated performance penalty. The use of structurally integrated smart devices will minimize the mechanical and subsystem complexity of this implementation. The central innovations of the effort entail the modification of prior chevron designs to include a small cut that relaxes structural stiffness without compromising the desired flow characteristics over the surface; the reorientation of SMA actuation devices to apply forces to deflect the chevron tip, exploiting this relaxed stiffness; and the use of high-temperature SMA (HTSMA) materials to enable operation in the demanding core chevron environment. The overall conclusion of these design studies was that the cut chevron concept is a critical enabling step in bringing the variable geometry core chevron within reach. The presence of the cut may be aerodynamically undesirable in some respects, but it is present only when the chevron is not immersed in the core jet exhaust. When deployed, the gap closes as the chevron tip enters the high-speed, high-temperature core stream. Aeroacoustic testing and flow visualization support the contention that this cut is inconsequential to chevron performance.

Computer-aided analysis of cutting processes for brittle materials

NASA Astrophysics Data System (ADS)

Ogorodnikov, A. I.; Tikhonov, I. N.

2017-12-01

This paper is focused on 3D computer simulation of cutting processes for brittle materials and silicon wafers. Computer-aided analysis of wafer scribing and dicing is carried out with the use of the ANSYS CAE (computer-aided engineering) software, and a parametric model of the processes is created by means of the internal ANSYS APDL programming language. Different types of tool tip geometry are analyzed to obtain internal stresses, such as a four-sided pyramid with an included angle of 120° and a tool inclination angle to the normal axis of 15°. The quality of the workpieces after cutting is studied by optical microscopy to verify the FE (finite-element) model. The disruption of the material structure during scribing occurs near the scratch and propagates into the wafer or over its surface at a short range. The deformation area along the scratch looks like a ragged band, but the stress width is rather low. The theory of cutting brittle semiconductor and optical materials is developed on the basis of the advanced theory of metal turning. The fall of stress intensity along the normal on the way from the tip point to the scribe line can be predicted using the developed theory and with the verified FE model. The crystal quality and dimensions of defects are determined by the mechanics of scratching, which depends on the shape of the diamond tip, the scratching direction, the velocity of the cutting tool and applied force loads. The disunity is a rate-sensitive process, and it depends on the cutting thickness. The application of numerical techniques, such as FE analysis, to cutting problems enhances understanding and promotes the further development of existing machining technologies.

High frequency data acquisition system for space shuttle main engine testing

NASA Technical Reports Server (NTRS)

Lewallen, Pat

1987-01-01

The high frequency data acquisition system developed for the Space Shuttle Main Engine (SSME) single engine test facility at the National Space Technology Laboratories is discussed. The real time system will provide engineering data for a complete set of SSME instrumentation (approx. 100 measurements) within 4 hours following engine cutoff, a decrease of over 48 hours from the previous analog tape based system.

Xiaowen Chen | NREL

Science.gov Websites

Xiaowen Chen Photo of Xiaowen Chen Xiaowen Chen Researcher IV-Chemical Engineering Xiaowen.Chen Education Ph.D., Chemical Engineering, University of Maine, 2009 M.S., Chemical Engineering, University of Maine, 2005 B.S., Chemical Engineering in Polymer Science and Technology, Nanjing University of Science

76 FR 8321 - Special Conditions: Pratt and Whitney Canada Model PW210S Turboshaft Engine

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-14

... contact Marc Bouthillier, ANE-111, Engine and Propeller Directorate, Aircraft Certification Service, 12... contact Vincent Bennett, ANE-7 Engine and Propeller Directorate, Aircraft Certification Service, 12 New... helicopter will incorporate a main rotor brake what will allow the engine main output shaft and power turbine...

Field Tests of In-Service Modifications to Improve Performance of An Icebreaker Main Diesel Engine

DOT National Transportation Integrated Search

1977-08-01

Field tests of in-service modifications to improve engine efficiency and lower the emissions were performed on the no. 3 main diesel engine of the USCGC Mackinaw (WAGB-83). This engine is a model 38D8-1/8 manufactured by Colt Industries, Fairbanks Mo...

Panel cutting method: new approach to generate panels on a hull in Rankine source potential approximation

NASA Astrophysics Data System (ADS)

Choi, Hee-Jong; Chun, Ho-Hwan; Park, Il-Ryong; Kim, Jin

2011-12-01

In the present study, a new hull panel generation algorithm, namely panel cutting method, was developed to predict flow phenomena around a ship using the Rankine source potential based panel method, where the iterative method was used to satisfy the nonlinear free surface condition and the trim and sinkage of the ship was taken into account. Numerical computations were performed to investigate the validity of the proposed hull panel generation algorithm for Series 60 (CB=0.60) hull and KRISO container ship (KCS), a container ship designed by Maritime and Ocean Engineering Research Institute (MOERI). The computational results were validated by comparing with the existing experimental data.

Space shuttle three main engine return to launch site abort

NASA Technical Reports Server (NTRS)

Carter, J. F.; Bown, R. L.

1975-01-01

A Return-to-Launch-Site (RTLS) abort with three Space Shuttle Main Engines (SSME) operational was examined. The results are trajectories and main engine cutoff conditions that are approximately the same as for a two SSME case. Requiring the three SSME solution to match the two SSME abort eliminates additional crew training and is accomplished with negligible software impact.

Drill Cuttings-based Methodology to Optimize Multi-stage Hydraulic Fracturing in Horizontal Wells and Unconventional Gas Reservoirs

NASA Astrophysics Data System (ADS)

Ortega Mercado, Camilo Ernesto

Horizontal drilling and hydraulic fracturing techniques have become almost mandatory technologies for economic exploitation of unconventional gas reservoirs. Key to commercial success is minimizing the risk while drilling and hydraulic fracturing these wells. Data collection is expensive and as a result this is one of the first casualties during budget cuts. As a result complete data sets in horizontal wells are nearly always scarce. In order to minimize the data scarcity problem, the research addressed throughout this thesis concentrates on using drill cuttings, an inexpensive direct source of information, for developing: 1) A new methodology for multi-stage hydraulic fracturing optimization of horizontal wells without any significant increases in operational costs. 2) A new method for petrophysical evaluation in those wells with limited amount of log information. The methods are explained using drill cuttings from the Nikanassin Group collected in the Deep Basin of the Western Canada Sedimentary Basin (WCSB). Drill cuttings are the main source of information for the proposed methodology in Item 1, which involves the creation of three 'log tracks' containing the following parameters for improving design of hydraulic fracturing jobs: (a) Brittleness Index, (b) Measured Permeability and (c) An Indicator of Natural Fractures. The brittleness index is primarily a function of Poisson's ratio and Young Modulus, parameters that are obtained from drill cuttings and sonic logs formulations. Permeability is measured on drill cuttings in the laboratory. The indication of natural fractures is obtained from direct observations on drill cuttings under the microscope. Drill cuttings are also the main source of information for the new petrophysical evaluation method mentioned above in Item 2 when well logs are not available. This is important particularly in horizontal wells where the amount of log data is almost non-existent in the vast majority of the wells. By combining data from drill cuttings and previously available empirical relationships developed from cores it is possible to estimate water saturations, pore throat apertures, capillary pressures, flow units, porosity (or cementation) exponent m, true formation resistivity Rt, distance to a water table (if present), and to distinguish the contributions of viscous and diffusion-like flow in the tight gas formation. The method further allows the construction of Pickett plots using porosity and permeability obtained from drill cuttings, without previous availability of well logs. The method assumes the existence of intervals at irreducible water saturation, which is the case of the Nikanassin Group throughout the gas column. The new methods mentioned above are not meant to replace the use of detailed and sophisticated evaluation techniques. But the proposed methods provide a valuable and practical aid in those cases where geomechanical and petrophysical information are scarce.

Prediction of laser cutting heat affected zone by extreme learning machine

NASA Astrophysics Data System (ADS)

Anicic, Obrad; Jović, Srđan; Skrijelj, Hivzo; Nedić, Bogdan

2017-01-01

Heat affected zone (HAZ) of the laser cutting process may be developed based on combination of different factors. In this investigation the HAZ forecasting, based on the different laser cutting parameters, was analyzed. The main goal was to predict the HAZ according to three inputs. The purpose of this research was to develop and apply the Extreme Learning Machine (ELM) to predict the HAZ. The ELM results were compared with genetic programming (GP) and artificial neural network (ANN). The reliability of the computational models were accessed based on simulation results and by using several statistical indicators. Based upon simulation results, it was demonstrated that ELM can be utilized effectively in applications of HAZ forecasting.

Parametric Optimization of Wire Electrical Discharge Machining of Powder Metallurgical Cold Worked Tool Steel using Taguchi Method

NASA Astrophysics Data System (ADS)

Sudhakara, Dara; Prasanthi, Guvvala

2017-04-01

Wire Cut EDM is an unconventional machining process used to build components of complex shape. The current work mainly deals with optimization of surface roughness while machining P/M CW TOOL STEEL by Wire cut EDM using Taguchi method. The process parameters of the Wire Cut EDM is ON, OFF, IP, SV, WT, and WP. L27 OA is used for to design of the experiments for conducting experimentation. In order to find out the effecting parameters on the surface roughness, ANOVA analysis is engaged. The optimum levels for getting minimum surface roughness is ON = 108 µs, OFF = 63 µs, IP = 11 A, SV = 68 V and WT = 8 g.

Characteristics and Machining Performance of TiN and TiAlN Coatings on a Milling Cutter

NASA Astrophysics Data System (ADS)

Sarwar, Mohammed; Haider, Julfikar

2011-01-01

Titanium Nitride (TiN) coating deposited by Physical Vapour Deposition (PVD) or Chemical Vapour Deposition (CVD) techniques on cutting tools (single point or multipoint) has contributed towards the improvement of tool life, productivity and product quality [1]. Addition of Al in TiN coating (e.g., TiAlN or AlTiN) has further improved the coating properties required for machining applications [2, 3]. This work presents a comparative investigation on TiN and TiAlN coatings deposited on to a Powder Metallurgy High Speed Steel (PM HSS) milling cutter used for machining bimetal (M42+D6A) steel strips. PVD (Arc evaporation) technique was used to deposit the coatings after carefully preparing the cutting edges of the milling cutter. Microstructure, chemical composition, hardness and adhesion of the coatings have been characterised using different techniques. The incorporation of Al into TiN coating results in an improvement in hardness, wear resistance and cutting performance. Examination of the worn flank in the coated cutting edges revealed that abrasive and adhesive wear are the predominant failure mechanisms. Tool designers, coating suppliers and manufacturing engineers could benefit from the information provided.

In situ repair of a failed compression fitting

DOEpatents

Wolbert, R.R.; Jandrasits, W.G.

1985-08-05

A method and apparatus for the in situ repair of a failed compression fitting is provided. Initially, a portion of a guide tube is inserted coaxially in the bore of the compression fitting and locked therein. A close fit dethreading device is then coaxially mounted on the guide tube to cut the threads from the fitting. Thereafter, the dethreading device and guide tube are removed and a new fitting is inserted onto the dethreaded fitting with the body of the new fitting overlaying the dethreaded portion. Finally, the main body of the new fitting is welded to the main body of the old fitting whereby a new threaded portion of the replacement fitting is precisely coaxial with the old threaded portion. If needed, a bushing is located on the dethreaded portion which is sized to fit snugly between the dethreaded portion and the new fitting. Preferably, the dethreading device includes a cutting tool which is moved incrementally in a radial direction whereby the threads are cut from the threaded portion of the failed fitting in increments.

In situ repair of a failed compression fitting

DOEpatents

Wolbert, Ronald R.; Jandrasits, Walter G.

1986-01-01

A method and apparatus for the in situ repair of a failed compression fitg is provided. Initially, a portion of a guide tube is inserted coaxially in the bore of the compression fitting and locked therein. A close fit dethreading device is then coaxially mounted on the guide tube to cut the threads from the fitting. Thereafter, the dethreading device and guide tube are removed and a new fitting is inserted onto the dethreaded fitting with the body of the new fitting overlaying the dethreaded portion. Finally, the main body of the new fitting is welded to the main body of the old fitting whereby a new threaded portion of the replacement fitting is precisely coaxial with the old threaded portion. If needed, a bushing is located on the dethreaded portion which is sized to fit snugly between the dethreaded portion and the new fitting. Preferably, the dethreading device includes a cutting tool which is moved incrementally in a radial direction whereby the threads are cut from the threaded portion of the failed fitting in increments.

A-3 First Tree Cutting

NASA Technical Reports Server (NTRS)

2007-01-01

Tree clearing for the site of the new A-3 Test Stand at Stennis Space center began June 13. NASA's first new large rocket engine test stand to be built since the site's inception, A-3 construction begins a historic era for America's largest rocket engine test complex. The 300-foot-tall structure is scheduled for completion in August 2010. A-3 will perform altitude tests on the Constellation's J-2X engine that will power the upper stage of the Ares I crew launch vehicle and earth departure stage of the Ares V cargo launch vehicle. The Constellation Program, NASA's plan for carrying out the nation's Vision for Space Exploration, will return humans to the moon and eventually carry them to Mars and beyond.

A-3 First Tree Cutting

NASA Image and Video Library

2007-06-13

Tree clearing for the site of the new A-3 Test Stand at Stennis Space center began June 13. NASA's first new large rocket engine test stand to be built since the site's inception, A-3 construction begins a historic era for America's largest rocket engine test complex. The 300-foot-tall structure is scheduled for completion in August 2010. A-3 will perform altitude tests on the Constellation's J-2X engine that will power the upper stage of the Ares I crew launch vehicle and earth departure stage of the Ares V cargo launch vehicle. The Constellation Program, NASA's plan for carrying out the nation's Vision for Space Exploration, will return humans to the moon and eventually carry them to Mars and beyond.

Engineering evaluation of SSME dynamic data from engine tests and SSV flights

NASA Technical Reports Server (NTRS)

1986-01-01

An engineering evaluation of dynamic data from SSME hot firing tests and SSV flights is summarized. The basic objective of the study is to provide analyses of vibration, strain and dynamic pressure measurements in support of MSFC performance and reliability improvement programs. A brief description of the SSME test program is given and a typical test evaluation cycle reviewed. Data banks generated to characterize SSME component dynamic characteristics are described and statistical analyses performed on these data base measurements are discussed. Analytical models applied to define the dynamic behavior of SSME components (such as turbopump bearing elements and the flight accelerometer safety cut-off system) are also summarized. Appendices are included to illustrate some typical tasks performed under this study.

Method of fabricating a rocket engine combustion chamber

NASA Technical Reports Server (NTRS)

Holmes, Richard R. (Inventor); Mckechnie, Timothy N. (Inventor); Power, Christopher A. (Inventor); Daniel, Ronald L., Jr. (Inventor); Saxelby, Robert M. (Inventor)

1993-01-01

A process for making a combustion chamber for a rocket engine wherein a copper alloy in particle form is injected into a stream of heated carrier gas in plasma form which is then projected onto the inner surface of a hollow metal jacket having the configuration of a rocket engine combustion chamber is described. The particles are in the plasma stream for a sufficient length of time to heat the particles to a temperature such that the particles will flatten and adhere to previously deposited particles but will not spatter or vaporize. After a layer is formed, cooling channels are cut in the layer, then the channels are filled with a temporary filler and another layer of particles is deposited.

Thin EFG octagons

NASA Astrophysics Data System (ADS)

Kalejs, J. P.

1994-03-01

This report describes work to advance the manufacturing line capabilities in crystal growth and laser cutting of Mobil Solar's unique edge-defined film-fed growth (EFG) octagon technology and to reduce the manufacturing costs of 10 cm x 10 cm polycrystalline silicon EFG wafers. The report summarizes the significant technical improvements in EFG technology achieved in the first 6 months of the PVMaT Phase 2 and the success in meeting program milestones. Technical results are reported for each of the three main pregrain areas: Task 5 -- Thin octagon growth (crystal growth) to reduce the thickness of the octagon to 200 microns; Task 6 -- Laser cutting-to improve the laser cutting process so as to produce wafers with decreased laser cutting damage at increased wafer throughput rates; and Task 7 -- Process control and product specification to implement advanced strategies in crystal growth process control and productivity designed to increase wafer yields.

A review of the use of wear-resistant coatings in the cutting-tool industry

NASA Technical Reports Server (NTRS)

Salik, J.

1983-01-01

The main mechanisms involved in the wear of cutting tools are reviewed. Evaluation of the different coating properties required for the reduction of the different kinds of wear was also reviewed. The types of coatings and their ranges of applicability are presented and discussed in view of their properties. Various coating processes as well as their advantages and shortcomings are described. Potential future developments in the field of wear-resistant coatings are discussed.

3. Oblique view of building in setting; view to northwest, ...

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

3. Oblique view of building in setting; view to northwest, 65mm lens. Railroad cut in foreground was made in 1928 when Southern Pacific Railroad realigned its main line in connection with the construction of its Martinez-Benicia Bridge. It was this cut which led to continual settlement of the southeast corner of the building, resulting in its structural failure. - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 5: Main Injector LOX Inlet analysis

NASA Technical Reports Server (NTRS)

Violett, Rebeca S.

1989-01-01

The analysis performed on the Main Injector LOX Inlet Assembly located on the Space Shuttle Main Engine is summarized. An ANSYS finite element model of the inlet assemably was built and executed. Static stress analysis was also performed.

Tripropellant engine study

NASA Technical Reports Server (NTRS)

Wheeler, D. B.

1978-01-01

Engine performance data, combustion gas thermodynamic properties, and turbine gas parameters were determined for various high power cycle engine configurations derived from the space shuttle main engine that will allow sequential burning of LOX/hydrocarbon and LOX/hydrogen fuels. Both stage combustion and gas generator pump power cycles were considered. Engine concepts were formulated for LOX/RP-1, LOX/CH4, and LOX/C3H8 propellants. Flowrates and operating conditions were established for this initial set of engine systems, and the adaptability of the major components of shuttle main engine was investigated.

COBRA System Engineering Processes to Achieve SLI Strategic Goals

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2003-01-01

The COBRA Prototype Main Engine Development Project was an endeavor conducted as a joint venture between Pratt & Whitney and Aerojet to conduct risk reduction in LOX/LH2 main engine technology for the NASA Space Launch Initiative (SLI). During the seventeen months of the project (April 2001 to September 2002), approximately seventy reviews were conducted, beginning with the Engine Systems Requirements Review (SRR) and ending with the Engine Systems Interim Design Review (IDR). This paper discusses some of the system engineering practices used to support the reviews and the overall engine development effort.

Closeup view of the top of Space Shuttle Main Engine ...

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

Close-up view of the top of Space Shuttle Main Engine (SSME) 2057 mounted in a SSME Engine Handler in the Vertical Processing area of the SSME Processing Facility at Kennedy Space Center. The most prominent components in this view is the large Low-Pressure Oxidizer Turbopump (LPOTP) Discharge Duct wrapping itself around the right side of the engine assembly. The smaller tube to the left of LPOTP Discharge Duct is the High-Pressure Oxidizer Duct used to supply the turbine of the LPOTP. The other major feature in this view is the Low-Pressure Fuel Turbopump at the top of the engine assembly. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

STS-26 Discovery, OV-103, SSME (2019) installed in position number one at KSC

NASA Image and Video Library

1988-01-10

S88-29076 (10 Jan 1988) --- KSC employees work together to carefully guide a 7,000 pound main engine into the number one position in Discovery's aft compartment. Because of the engine's weight and size, special handling equipment is needed to perform the installation. Discovery is currently being prepared for the upcoming STS-26 mission in bay 1 of the Orbiter Processing Facility. This engine, 2019, arrived at KSC on Jan. 6 and was installed Jan. 10. The other two engines are scheduled to be installed later this month. The shuttle's three main liquid fueled engines provide the main propulsion for the orbiter vehicle. The cluster of three engines operate in parallel with the solid rocket boosters during the initial ascent.

Emissions of NOx, particle mass and particle numbers from aircraft main engines, APU's and handling equipment at Copenhagen Airport

NASA Astrophysics Data System (ADS)

Winther, Morten; Kousgaard, Uffe; Ellermann, Thomas; Massling, Andreas; Nøjgaard, Jacob Klenø; Ketzel, Matthias

2015-01-01

This paper presents a detailed emission inventory for NOx, particle mass (PM) and particle numbers (PN) for aircraft main engines, APU's and handling equipment at Copenhagen Airport (CPH) based on time specific activity data and representative emission factors for the airport. The inventory has a high spatial resolution of 5 m × 5 m in order to be suited for further air quality dispersion calculations. Results are shown for the entire airport and for a section of the airport apron area ("inner apron") in focus. The methodology presented in this paper can be used to quantify the emissions from aircraft main engines, APU and handling equipment in other airports. For the entire airport, aircraft main engines is the largest source of fuel consumption (93%), NOx, (87%), PM (61%) and PN (95%). The calculated fuel consumption [NOx, PM, PN] shares for APU's and handling equipment are 5% [4%, 8%, 5%] and 2% [9%, 31%, 0%], respectively. At the inner apron area for handling equipment the share of fuel consumption [NOx, PM, PN] are 24% [63%, 75%, 2%], whereas APU and main engines shares are 43% [25%, 19%, 54%], and 33% [11%, 6%, 43%], respectively. The inner apron NOx and PM emission levels are high for handling equipment due to high emission factors for the diesel fuelled handling equipment and small for aircraft main engines due to small idle-power emission factors. Handling equipment is however a small PN source due to the low number based emission factors. Jet fuel sulphur-PM sensitivity calculations made in this study with the ICAO FOA3.0 method suggest that more than half of the PM emissions from aircraft main engines at CPH originate from the sulphur content of the fuel used at the airport. Aircraft main engine PN emissions are very sensitive to the underlying assumptions. Replacing this study's literature based average emission factors with "high" and "low" emission factors from the literature, the aircraft main engine PN emissions were estimated to change with a factor of 14.

Adventitious rooting declines with the vegetative to reproductive switch and involves a changed auxin homeostasis.

PubMed

Rasmussen, Amanda; Hosseini, Seyed Abdollah; Hajirezaei, Mohammed-Reza; Druege, Uwe; Geelen, Danny

2015-03-01

Adventitious rooting, whereby roots form from non-root tissues, is critical to the forestry and horticultural industries that depend on propagating plants from cuttings. A major problem is that age of the tissue affects the ability of the cutting to form adventitious roots. Here, a model system has been developed using Pisum sativum to differentiate between different interpretations of ageing. It is shown that the decline in adventitious rooting is linked to the ontogenetic switch from vegetative to floral and is mainly attributed to the cutting base. Using rms mutants it is demonstrated that the decline is not a result of increased strigolactones inhibiting adventitious root formation. Monitoring endogenous levels of a range of other hormones including a range of cytokinins in the rooting zone revealed that a peak in jasmonic acid is delayed in cuttings from floral plants. Additionally, there is an early peak in indole-3-acetic acid levels 6h post excision in cuttings from vegetative plants, which is absent in cuttings from floral plants. These results were confirmed using DR5:GUS expression. Exogenous supplementation of young cuttings with either jasmonic acid or indole-3-acetic acid promoted adventitious rooting, but neither of these hormones was able to promote adventitious rooting in mature cuttings. DR5:GUS expression was observed to increase in juvenile cuttings with increasing auxin treatment but not in the mature cuttings. Therefore, it seems the vegetative to floral ontogenetic switch involves an alteration in the tissue's auxin homeostasis that significantly reduces the indole-3-acetic acid pool and ultimately results in a decline in adventitious root formation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Adventitious rooting declines with the vegetative to reproductive switch and involves a changed auxin homeostasis

PubMed Central

Rasmussen, Amanda; Hosseini, Seyed Abdollah; Hajirezaei, Mohammed-Reza; Druege, Uwe; Geelen, Danny

2015-01-01

Adventitious rooting, whereby roots form from non-root tissues, is critical to the forestry and horticultural industries that depend on propagating plants from cuttings. A major problem is that age of the tissue affects the ability of the cutting to form adventitious roots. Here, a model system has been developed using Pisum sativum to differentiate between different interpretations of ageing. It is shown that the decline in adventitious rooting is linked to the ontogenetic switch from vegetative to floral and is mainly attributed to the cutting base. Using rms mutants it is demonstrated that the decline is not a result of increased strigolactones inhibiting adventitious root formation. Monitoring endogenous levels of a range of other hormones including a range of cytokinins in the rooting zone revealed that a peak in jasmonic acid is delayed in cuttings from floral plants. Additionally, there is an early peak in indole-3-acetic acid levels 6h post excision in cuttings from vegetative plants, which is absent in cuttings from floral plants. These results were confirmed using DR5:GUS expression. Exogenous supplementation of young cuttings with either jasmonic acid or indole-3-acetic acid promoted adventitious rooting, but neither of these hormones was able to promote adventitious rooting in mature cuttings. DR5:GUS expression was observed to increase in juvenile cuttings with increasing auxin treatment but not in the mature cuttings. Therefore, it seems the vegetative to floral ontogenetic switch involves an alteration in the tissue’s auxin homeostasis that significantly reduces the indole-3-acetic acid pool and ultimately results in a decline in adventitious root formation. PMID:25540438

A new device to test cutting efficiency of mechanical endodontic instruments

PubMed Central

Rubini, Alessio Giansiracusa; Plotino, Gianluca; Al-Sudani, Dina; Grande, Nicola M.; Putorti, Ermanno; Sonnino, GianPaolo; Cotti, Elisabetta; Testarelli, Luca; Gambarini, Gianluca

2014-01-01

Background The purpose of the present study was to introduce a new device specifically designed to evaluate the cutting efficiency of mechanically driven endodontic instruments. Material/Methods Twenty new Reciproc R25 (VDW, Munich, Germany) files were used to be investigated in the new device developed to test the cutting ability of endodontic instruments. The device consists of a main frame to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1mm. The instruments were activated by using a torque-controlled motor (Silver Reciproc; VDW, Munich, Germany) in a reciprocating movement by the “Reciproc ALL” program (Group 1) and in counter-clockwise rotation at 300 rpm (Group 2). Mean and standard deviations of each group were calculated and data were statistically analyzed with a one-way ANOVA test (P<0.05). Results Reciproc in reciprocation (Group 1) mean cut in the Plexiglas block was 8.6 mm (SD=0.6 mm), while Reciproc in rotation mean cut was 8.9 mm (SD=0.7 mm). There was no statistically significant difference between the 2 groups investigated (P>0.05). Conclusions The cutting testing device evaluated in the present study was reliable and easy to use and may be effectively used to test cutting efficiency of both rotary and reciprocating mechanical endodontic instruments. PMID:24603777

Surface topography and roughness of high-speed milled AlMn1Cu

NASA Astrophysics Data System (ADS)

Wang, Zhenhua; Yuan, Juntang; Yin, Zengbin; Hu, Xiaoqiu

2016-10-01

The aluminum alloy AlMn1Cu has been broadly applied for functional parts production because of its good properties. But few researches about the machining mechanism and the surface roughness were reported. The high-speed milling experiments are carried out in order to improve the machining quality and reveal the machining mechanism. The typical topography features of machined surface are observed by scan electron microscope(SEM). The results show that the milled surface topography is mainly characterized by the plastic shearing deformation surface and material piling zone. The material flows plastically along the end cutting edge of the flat-end milling tool and meanwhile is extruded by the end cutting edge, resulting in that materials partly adhere to the machined surface and form the material piling zone. As the depth of cut and the feed per tooth increase, the plastic flow of materials is strengthened and the machined surface becomes rougher. However, as the cutting speed increases, the plastic flow of materials is weakened and the milled surface becomes smoother. The cutting parameters (e.g. cutting speed, feed per tooth and depth of cut) influencing the surface roughness are analyzed. It can be concluded that the roughness of the machined surface formed by the end cutting edge is less than that by the cylindrical cutting edge when a cylindrical flat-end mill tool is used for milling. The proposed research provides the typical topography features of machined surface of the anti-rust aluminum alloy AlMn1Cu in high speed milling.

A theoretical approach to sound propagation and radiation for ducts with suppressors

NASA Technical Reports Server (NTRS)

Rice, E. J.; Sawdy, D. T.

1981-01-01

The several phenomena involved in theoretical prediction of the far-field sound radiation attenuation from an acoustically lined duct were studied. These include absorption by the suppressor, termination reflections, and far-field radiation. Extensive parametric studies show that the suppressor absorption performance can be correlated with mode cut-off ratio or angle of propagation. The other phenomena can be shown to depend explicitly upon mode cut-off ratio. A complete system can thus be generated which can be used to evaluate aircraft sound suppressors and which can be related to the sound source through the cut-off ratio-acoustic power distribution. Although the method is most fully developed for inlet suppressors, several aft radiated noise phenomena are also discussed. This simplified suppressor design and evaluation method is summarized, the recent improvements in the technique are presented, and areas where further refinement is necessary are discussed. Noise suppressor data from engine experiments are compared with the theoretical calculations.

RNA-dependent DNA endonuclease Cas9 of the CRISPR system: Holy Grail of genome editing?

PubMed

Gasiunas, Giedrius; Siksnys, Virginijus

2013-11-01

Tailor-made nucleases for precise genome modification, such as zinc finger or TALE nucleases, currently represent the state-of-the-art for genome editing. These nucleases combine a programmable protein module which guides the enzyme to the target site with a nuclease domain which cuts DNA at the addressed site. Reprogramming of these nucleases to cut genomes at specific locations requires major protein engineering efforts. RNA-guided DNA endonuclease Cas9 of the type II (clustered regularly interspaced short palindromic repeat) CRISPR-Cas system uses CRISPR RNA (crRNA) as a guide to locate the DNA target and the Cas9 protein to cut DNA. Easy programmability of the Cas9 endonuclease using customizable RNAs brings unprecedented flexibility and versatility for targeted genome modification. We highlight the potential of the Cas9 RNA-guided DNA endonuclease as a novel tool for genome surgery, and discuss possible constraints and future prospects. Copyright © 2013 Elsevier Ltd. All rights reserved.

Close coupling of pre- and post-processing vision stations using inexact algorithms

NASA Astrophysics Data System (ADS)

Shih, Chi-Hsien V.; Sherkat, Nasser; Thomas, Peter D.

1996-02-01

Work has been reported using lasers to cut deformable materials. Although the use of laser reduces material deformation, distortion due to mechanical feed misalignment persists. Changes in the lace patten are also caused by the release of tension in the lace structure as it is cut. To tackle the problem of distortion due to material flexibility, the 2VMethod together with the Piecewise Error Compensation Algorithm incorporating the inexact algorithms, i.e., fuzzy logic, neural networks and neural fuzzy technique, are developed. A spring mounted pen is used to emulate the distortion of the lace pattern caused by tactile cutting and feed misalignment. Using pre- and post-processing vision systems, it is possible to monitor the scalloping process and generate on-line information for the artificial intelligence engines. This overcomes the problems of lace distortion due to the trimming process. Applying the algorithms developed, the system can produce excellent results, much better than a human operator.

National Dam Safety Program. Lake Montowese Dam (M0 30151), Mississippi - Kaskaskia - St. Louis Basin, Jefferson County, Missouri. Phase I Inspection Report.

DTIC Science & Technology

1978-11-01

Williams, Chief Applied Engineering & Urban Geology Geology & Land Survey October 8, 1976 I Chart 2-11 APPENDIX _______--row]h NO. 1 : UPS7TREAM FACE 01...be cut out as indicated by the maintenance people. Otherwise the dam looks to be in a very good condition. I Edwin E. Luzten, Geologist Applied ... Engineering & Urban Geology Missouri Geological Survey lJuly 1i, 1973 hI I Chart 2-7 I ... . , ---- -i- - 3~ i Mf itS 0 I C)E R S. BON D .1%A

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020378 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020383 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

Expedition 40 crew in Node 2 after German - U.S. soccer game

NASA Image and Video Library

2014-06-26

ISS040-E-020384 (26 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, shaves the head of NASA astronaut Reid Wiseman, flight engineer, in the Unity node of the International Space Station. Gerst used hair clippers fashioned with a vacuum device to garner freshly cut hair. A friendly World Cup Soccer-related agreement between the crew members representing the USA, and Gerst, a German citizen who represents the European Space Agency, called for the American losers of a German-USA match to have their heads shaved. The German team won the match 1-0.

UNLV’s environmentally friendly Science and Engineering Building is monitored for earthquake shaking

USGS Publications Warehouse

Kalkan, Erol; Savage, Woody; Reza, Shahneam; Knight, Eric; Tian, Ying

2013-01-01

The University of Nevada Las Vegas’ (UNLV) Science and Engineering Building is at the cutting edge of environmentally friendly design. As the result of a recent effort by the U.S. Geological Survey’s National Strong Motion Project in cooperation with UNLV, the building is now also in the forefront of buildings installed with structural monitoring systems to measure response during earthquakes. This is particularly important because this is the first such building in Las Vegas. The seismic instrumentation will provide essential data to better understand the structural performance of buildings, especially in this seismically active region.

Efficient bone cutting with the novel diode pumped Er:YAG laser system: in vitro investigation and optimization of the treatment parameters

NASA Astrophysics Data System (ADS)

Stock, Karl; Diebolder, Rolf; Hausladen, Florian; Hibst, Raimund

2014-03-01

It is well known that flashlamp pumped Er:YAG lasers allow efficient bone ablation due to strong absorption at 3μm by water. Preliminary experiments revealed also a newly developed diode pumped Er:YAG laser system (Pantec Engineering AG) to be an efficient tool for use for bone surgery. The aim of the present in vitro study is the investigation of a new power increased version of the laser system with higher pulse energy and optimization of the treatment set-up to get high cutting quality, efficiency, and ablation depth. Optical simulations were performed to achieve various focus diameters and homogeneous beam profile. An appropriate experimental set-up with two different focusing units, a computer controlled linear stage with sample holder, and a shutter unit was realized. By this we are able to move the sample (slices of pig bone) with a defined velocity during the irradiation. Cutting was performed under appropriate water spray by moving the sample back and forth. After each path the ablation depth was measured and the focal plane was tracked to the actual bottom of the groove. Finally, the cuts were analyzed by light microcopy regarding the ablation quality and geometry, and thermal effects. In summary, the results show that with carefully adapted irradiation parameters narrow and deep cuts (ablation depth > 6mm, aspect ratio approx. 20) are possible without carbonization. In conclusion, these in vitro investigations demonstrate that high efficient bone cutting is possible with the diode pumped Er:YAG laser system using appropriate treatment set-up and parameters.

Effect of Built-Up Edge Formation during Stable State of Wear in AISI 304 Stainless Steel on Machining Performance and Surface Integrity of the Machined Part.

PubMed

Ahmed, Yassmin Seid; Fox-Rabinovich, German; Paiva, Jose Mario; Wagg, Terry; Veldhuis, Stephen Clarence

2017-10-25

During machining of stainless steels at low cutting -speeds, workpiece material tends to adhere to the cutting tool at the tool-chip interface, forming built-up edge (BUE). BUE has a great importance in machining processes; it can significantly modify the phenomenon in the cutting zone, directly affecting the workpiece surface integrity, cutting tool forces, and chip formation. The American Iron and Steel Institute (AISI) 304 stainless steel has a high tendency to form an unstable BUE, leading to deterioration of the surface quality. Therefore, it is necessary to understand the nature of the surface integrity induced during machining operations. Although many reports have been published on the effect of tool wear during machining of AISI 304 stainless steel on surface integrity, studies on the influence of the BUE phenomenon in the stable state of wear have not been investigated so far. The main goal of the present work is to investigate the close link between the BUE formation, surface integrity and cutting forces in the stable sate of wear for uncoated cutting tool during the cutting tests of AISI 304 stainless steel. The cutting parameters were chosen to induce BUE formation during machining. X-ray diffraction (XRD) method was used for measuring superficial residual stresses of the machined surface through the stable state of wear in the cutting and feed directions. In addition, surface roughness of the machined surface was investigated using the Alicona microscope and Scanning Electron Microscopy (SEM) was used to reveal the surface distortions created during the cutting process, combined with chip undersurface analyses. The investigated BUE formation during the stable state of wear showed that the BUE can cause a significant improvement in the surface integrity and cutting forces. Moreover, it can be used to compensate for tool wear through changing the tool geometry, leading to the protection of the cutting tool from wear.

Effect of Built-Up Edge Formation during Stable State of Wear in AISI 304 Stainless Steel on Machining Performance and Surface Integrity of the Machined Part

PubMed Central

Fox-Rabinovich, German; Wagg, Terry

2017-01-01

During machining of stainless steels at low cutting -speeds, workpiece material tends to adhere to the cutting tool at the tool–chip interface, forming built-up edge (BUE). BUE has a great importance in machining processes; it can significantly modify the phenomenon in the cutting zone, directly affecting the workpiece surface integrity, cutting tool forces, and chip formation. The American Iron and Steel Institute (AISI) 304 stainless steel has a high tendency to form an unstable BUE, leading to deterioration of the surface quality. Therefore, it is necessary to understand the nature of the surface integrity induced during machining operations. Although many reports have been published on the effect of tool wear during machining of AISI 304 stainless steel on surface integrity, studies on the influence of the BUE phenomenon in the stable state of wear have not been investigated so far. The main goal of the present work is to investigate the close link between the BUE formation, surface integrity and cutting forces in the stable sate of wear for uncoated cutting tool during the cutting tests of AISI 304 stainless steel. The cutting parameters were chosen to induce BUE formation during machining. X-ray diffraction (XRD) method was used for measuring superficial residual stresses of the machined surface through the stable state of wear in the cutting and feed directions. In addition, surface roughness of the machined surface was investigated using the Alicona microscope and Scanning Electron Microscopy (SEM) was used to reveal the surface distortions created during the cutting process, combined with chip undersurface analyses. The investigated BUE formation during the stable state of wear showed that the BUE can cause a significant improvement in the surface integrity and cutting forces. Moreover, it can be used to compensate for tool wear through changing the tool geometry, leading to the protection of the cutting tool from wear. PMID:29068405

Experimental evaluation of tool wear throughout a continuous stroke blanking process of quenched 22MnB5 ultra-high-strength steel

NASA Astrophysics Data System (ADS)

Vogt, S.; Neumayer, F. F.; Serkyov, I.; Jesner, G.; Kelsch, R.; Geile, M.; Sommer, A.; Golle, R.; Volk, W.

2017-09-01

Steel is the most common material used in vehicles’ chassis, which makes its research an important topic for the automotive industry. Recently developed ultra-high-strength steels (UHSS) provide extreme tensile strength up to 1,500 MPa and combine great crashworthiness with good weight reduction potential. However, in order to reach the final shape of sheet metal parts additional cutting steps such as trimming and piercing are often required. The final trimming of quenched metal sheets presents a huge challenge to a conventional process, mainly because of the required extreme cutting force. The high cutting impact, due to the materials’ brittleness, causes excessive tool wear or even sudden tool failure. Therefore, a laser is commonly used for the cutting process, which is time and energy consuming. The purpose of this paper is to demonstrate the capability of a conventional blanking tool design in a continuous stroke piercing process using boron steel 22MnB5 sheets. Two different types of tool steel were tested for their suitability as active cutting elements: electro-slag remelted (ESR) cold work tool steel Bohler K340 ISODUR and powder-metallurgic (PM) high speed steel Bohler S390 MICROCLEAN. A FEM study provided information about an optimized punch design, which withstands buckling under high cutting forces. The wear behaviour of the process was assessed by the tool wear of the active cutting elements as well as the quality of cut surfaces.

LC-MS Untargeted Metabolomics To Explain the Signal Metabolites Inducing Browning in Fresh-Cut Lettuce.

PubMed

García, Carlos J; García-Villalba, Rocío; Gil, María I; Tomas-Barberan, Francisco A

2017-06-07

Enzymatic browning is one of the main causes of quality loss in lettuce as a prepared and ready-to-eat cut salad. An untargeted metabolomics approach using UPLC-ESI-QTOF-MS was performed to explain the wound response of lettuce after cutting and to identify the metabolites responsible of browning. Two cultivars of Romaine lettuce with different browning susceptibilities were studied at short time intervals after cutting. From the total 5975 entities obtained from the raw data after alignment, filtration reduced the number of features to 2959, and the statistical analysis found that only 1132 entities were significantly different. Principal component analysis (PCA) clearly showed that these samples grouped according to cultivar and time after cutting. From those, only 15 metabolites belonging to lysophospholipids, oxylipin/jasmonate metabolites, and phenolic compounds were able to explain the browning process. These selected metabolites showed different trends after cutting; some decreased rapidly, others increased but decreased thereafter, whereas others increased during the whole period of storage. In general, the fast-browning cultivar showed a faster wound response and a higher raw intensity of some key metabolites than the slow-browning one. Just after cutting, the fast-browning cultivar contained 11 of the 15 browning-associated metabolites, whereas the slow-browning cultivar only had 5 of them. These metabolites could be used as biomarkers in breeding programs for the selection of lettuce cultivars with lower browning potential for fresh-cut applications.

Laboratory evaluation to reduce respirable crystalline silica dust when cutting concrete roofing tiles using a masonry saw.

PubMed

Carlo, Rebecca V; Sheehy, John; Feng, H Amy; Sieber, William K

2010-04-01

Respirable crystalline silica dust exposure in residential roofers is a recognized hazard resulting from cutting concrete roofing tiles. Roofers cutting tiles using masonry saws can be exposed to high concentrations of respirable dust. Silica exposures remain a serious threat for nearly two million U.S. construction workers. Although it is well established that respiratory diseases associated with exposure to silica dust are preventable, they continue to occur and cause disability or death. The effectiveness of both a commercially available local exhaust ventilation (LEV) system and a water suppression system in reducing silica dust was evaluated separately. The LEV system exhausted 0.24, 0.13, or 0.12 m(3)/sec of dust laden air, while the water suppression system supplied 0.13, 0.06, 0.03, or 0.02 L/sec of water to the saw blade. Using a randomized block design, implemented under laboratory conditions, the aforementioned conditions were evaluated independently on two types of concrete roofing tiles (s-shape and flat) using the same saw and blade. Each engineering control (LEV or water suppression) was replicated eight times, or four times for each type of tile. Analysis of variance was performed by comparing the mean airborne respirable dust concentrations generated during each run and engineering control treatment. The use of water controls and ventilation controls compared with the "no control" treatment resulted in a statistically significant (p < 0.05) reduction of mean respirable dust concentrations generated per tile cut. The percent reduction for respirable dust concentrations was 99% for the water control and 91% for the LEV. Results suggest that water is an effective method for reducing crystalline silica exposures. However, water damage potential, surface discolorations, cleanup, slip hazards, and other requirements may make the use of water problematic in many situations. Concerns with implementing an LEV system to control silica dust exposures include sufficient capture velocity, additional weight of the saw with the LEV system, electricity connections, and cost of air handling unit.

Selection of a Prototype Engine Monitor for Coast Guard Main Diesel Propulsion

DOT National Transportation Integrated Search

1979-04-01

A diesel engine monitor system has been synthesized from several parameter measurement subsystems which employ measurement techniques suitable for use on the main propulsion engines in U.S. Coast Cutters. The primary functions of the system are to mo...

"Knowledge Workers" as the New Apprentices: The Influence of Organisational Autonomy, Goals and Values on the Nurturing of Expertise

ERIC Educational Resources Information Center

Fuller, Alison; Unwin, Lorna

2010-01-01

This paper explores the concept of apprenticeship in the context of the professional formation of knowledge workers. It draws on evidence from research conducted in two knowledge intensive organizations: a research-intensive, elite university; and a "cutting edge" software engineering company. In the former, we investigated the learning…

Can a biologist fix a smartphone?-Just hack it!

PubMed

Kamoun, Sophien

2017-05-08

Biological systems integrate multiscale processes and networks and are, therefore, viewed as difficult to dissect. However, because of the clear-cut separation between the software code (the information encoded in the genome sequence) and hardware (organism), genome editors can operate as software engineers to hack biological systems without any particularly deep understanding of the complexity of the systems.

An Archeological Overview and Management Plan for the Stratford Army Engine Plant.

DTIC Science & Technology

1984-02-01

Stratford-upon-Avon, England (Bixby 1974:266). The American Shakespeare Festival Theatre and Academy, attended by hundreds of thousands of visitors...cut and fill activities (GDAs 3, 4 and 5, Table 3-1, Figure 3-1). A companion grading and contour map (Dwg. B864x2) showing cross sections through the