NASA's B377SGT Super Guppy Turbine cargo aircraft touches down at Edwards Air Force Base, Calif. on

NASA Technical Reports Server (NTRS)

2000-01-01

NASA's B377SGT Super Guppy Turbine cargo aircraft touches down at Edwards Air Force Base, Calif. on June 11, 2000 to deliver the latest version of the X-38 flight test vehicle to NASA's Dryden Flight Research Center. The B-377SGT Super Guppy Turbine evolved from the 1960s-vintage Pregnant Guppy, Mini Guppy and Super Guppy, used for transporting sections of the Saturn rocket used for the Apollo program moon launches and other outsized cargo. The various Guppies were modified from 1940's and 50's-vintage Boeing Model 377 and C-97 Stratocruiser airframes by Aero Spacelines, Inc., which operated the aircraft for NASA. NASA's Flight Research Center assisted in certification testing of the first Pregnant Guppy in 1962. One of the turboprop-powered Super Guppies, built up from a YC-97J airframe, last appeared at Dryden in May, 1976 when it was used to transport the HL-10 and X-24B lifting bodies from Dryden to the Air Force Museum at Wright-Patterson Air Force Base, Ohio. NASA's present Super Guppy Turbine, the fourth and last example of the final version, first flew in its outsized form in 1980. It and its three sister ships were built in the 1970s for Europe's Airbus Industrie to ferry outsized structures for Airbus jetliners to the final assembly plant in Toulouse, France. It later was acquired by the European Space Agency, and then acquired by NASA in late 1997 for transport of large structures for the International Space Station to the launch site. It replaced the earlier-model Super Guppy, which has been retired and is used for spare parts. NASA's Super Guppy Turbine carries NASA registration number N941NA, and is based at Ellington Field near the Johnson Space Center. For more information on NASA's Super Guppy Turbine, log onto the Johnson Space Center Super Guppy web page at http://spaceflight.nasa.gov/station/assembly/superguppy/

Blades of Glory: An Energy.gov Mini-Doc – The 2016 Collegiate Wind Competition

ScienceCinema

Zayas, Jose; Newcomb, Charles

2018-01-16

In this short documentary, we follow three collegiate teams who are participating in this year’s U.S. Department of Energy Collegiate Wind Competition in New Orleans. Learn about their experiences and why the competition is important for America’s clean energy future. The competition provides undergraduates with real-world skills they need to enter tomorrow’s clean energy workforce by challenging them to develop and deliver a business plan, establish a deployment strategy, and build and test a wind turbine.

Power electronic supply system with the wind turbine dedicated for average power receivers

NASA Astrophysics Data System (ADS)

Widerski, Tomasz; Skrzypek, Adam

2018-05-01

This article presents the original project of the AC-DC-AC converter dedicated to low power wind turbines. Such a set can be a good solution for powering isolated objects that do not have access to the power grid, for example isolated houses, mountain lodges or forester's lodges, where they can replace expensive diesel engine generators. An additional source of energy in the form of a mini-wind farm is also a good alternative to yachts, marinas and tent sites, which are characterized by relatively low power consumption. This article presents a designed low power wind converter that is dedicated to these applications. The main design idea of the authors was to create a device that converts the very wide range input voltage directly to a stable 230VAC output voltage without the battery buffer. Authors focused on maximum safety of using and service. The converter contains the thermal protection, short-circuit protection and overvoltage protection. The components have been selected in such a way as to ensure that the device functions as efficiently as possible.

The accuracy of portable peak flow meters.

PubMed

Miller, M R; Dickinson, S A; Hitchings, D J

1992-11-01

The variability of peak expiratory flow (PEF) is now commonly used in the diagnosis and management of asthma. It is essential for PEF meters to have a linear response in order to obtain an unbiased measurement of PEF variability. As the accuracy and linearity of portable PEF meters have not been rigorously tested in recent years this aspect of their performance has been investigated. The response of several portable PEF meters was tested with absolute standards of flow generated by a computer driven, servo controlled pump and their response was compared with that of a pneumotachograph. For each device tested the readings were highly repeatable to within the limits of accuracy with which the pointer position can be assessed by eye. The between instrument variation in reading for six identical devices expressed as a 95% confidence limit was, on average across the range of flows, +/- 8.5 l/min for the Mini-Wright, +/- 7.9 l/min for the Vitalograph, and +/- 6.4 l/min for the Ferraris. PEF meters based on the Wright meter all had similar error profiles with overreading of up to 80 l/min in the mid flow range from 300 to 500 l/min. This overreading was greatest for the Mini-Wright and Ferraris devices, and less so for the original Wright and Vitalograph meters. A Micro-Medical Turbine meter was accurate up to 400 l/min and then began to underread by up to 60 l/min at 720 l/min. For the low range devices the Vitalograph device was accurate to within 10 l/min up to 200 l/min, with the Mini-Wright overreading by up to 30 l/min above 150 l/min. Although the Mini-Wright, Ferraris, and Vitalograph meters gave remarkably repeatable results their error profiles for the full range meters will lead to important errors in recording PEF variability. This may lead to incorrect diagnosis and bias in implementing strategies of asthma treatment based on PEF measurement.

The accuracy of portable peak flow meters.

PubMed Central

Miller, M R; Dickinson, S A; Hitchings, D J

1992-01-01

BACKGROUND: The variability of peak expiratory flow (PEF) is now commonly used in the diagnosis and management of asthma. It is essential for PEF meters to have a linear response in order to obtain an unbiased measurement of PEF variability. As the accuracy and linearity of portable PEF meters have not been rigorously tested in recent years this aspect of their performance has been investigated. METHODS: The response of several portable PEF meters was tested with absolute standards of flow generated by a computer driven, servo controlled pump and their response was compared with that of a pneumotachograph. RESULTS: For each device tested the readings were highly repeatable to within the limits of accuracy with which the pointer position can be assessed by eye. The between instrument variation in reading for six identical devices expressed as a 95% confidence limit was, on average across the range of flows, +/- 8.5 l/min for the Mini-Wright, +/- 7.9 l/min for the Vitalograph, and +/- 6.4 l/min for the Ferraris. PEF meters based on the Wright meter all had similar error profiles with overreading of up to 80 l/min in the mid flow range from 300 to 500 l/min. This overreading was greatest for the Mini-Wright and Ferraris devices, and less so for the original Wright and Vitalograph meters. A Micro-Medical Turbine meter was accurate up to 400 l/min and then began to underread by up to 60 l/min at 720 l/min. For the low range devices the Vitalograph device was accurate to within 10 l/min up to 200 l/min, with the Mini-Wright overreading by up to 30 l/min above 150 l/min. CONCLUSION: Although the Mini-Wright, Ferraris, and Vitalograph meters gave remarkably repeatable results their error profiles for the full range meters will lead to important errors in recording PEF variability. This may lead to incorrect diagnosis and bias in implementing strategies of asthma treatment based on PEF measurement. PMID:1465746

Members of the flight and ground crews prepare to unload equipment from NASA's B377SGT Super Guppy T

NASA Technical Reports Server (NTRS)

2000-01-01

Members of the flight and ground crews prepare to unload equipment from NASA's B377SGT Super Guppy Turbine cargo aircraft on the ramp at NASA's Dryden Flight Research Center at Edwards Air Force Base, Calif. The outsize cargo plane had delivered the latest version of the X-38 flight test vehicle to NASA Dryden when this photo was taken on June 11, 2000. The B-377SGT Super Guppy Turbine evolved from the 1960s-vintage Pregnant Guppy, Mini Guppy and Super Guppy, used for transporting sections of the Saturn rocket used for the Apollo program moon launches and other outsized cargo. The various Guppies were modified from 1940's and 50's-vintage Boeing Model 377 and C-97 Stratocruiser airframes by Aero Spacelines, Inc., which operated the aircraft for NASA. NASA's Flight Research Center assisted in certification testing of the first Pregnant Guppy in 1962. One of the turboprop-powered Super Guppies, built up from a YC-97J airframe, last appeared at Dryden in May, 1976 when it was used to transport the HL-10 and X-24B lifting bodies from Dryden to the Air Force Museum at Wright-Patterson Air Force Base, Ohio. NASA's present Super Guppy Turbine, the fourth and last example of the final version, first flew in its outsized form in 1980. It and its three sister ships were built in the 1970s for Europe's Airbus Industrie to ferry outsized structures for Airbus jetliners to the final assembly plant in Toulouse, France. It later was acquired by the European Space Agency, and then acquired by NASA in late 1997 for transport of large structures for the International Space Station to the launch site. It replaced the earlier-model Super Guppy, which has been retired and is used for spare parts. NASA's Super Guppy Turbine carries NASA registration number N941NA, and is based at Ellington Field near the Johnson Space Center. For more information on NASA's Super Guppy Turbine, log onto the Johnson Space Center Super Guppy web page at http://spaceflight.nasa.gov/station/assembly/superguppy/

Tom test 8/26/02 11:45am

NASA Technical Reports Server (NTRS)

2000-01-01

Members of the flight and ground crews prepare to unload equipment from NASA's B377SGT Super Guppy Turbine cargo aircraft on the ramp at NASA's Dryden Flight Research Center at Edwards Air Force Base, Calif. The outsize cargo plane had delivered the latest version of the X-38 flight test vehicle to NASA Dryden when this photo was taken on June 11, 2000. The B-377SGT Super Guppy Turbine evolved from the 1960s-vintage Pregnant Guppy, Mini Guppy and Super Guppy, used for transporting sections of the Saturn rocket used for the Apollo program moon launches and other outsized cargo. The various Guppies were modified from 1940's and 50's-vintage Boeing Model 377 and C-97 Stratocruiser airframes by Aero Spacelines, Inc., which operated the aircraft for NASA. NASA's Flight Research Center assisted in certification testing of the first Pregnant Guppy in 1962. One of the turboprop-powered Super Guppies, built up from a YC-97J airframe, last appeared at Dryden in May, 1976 when it was used to transport the HL-10 and X-24B lifting bodies from Dryden to the Air Force Museum at Wright-Patterson Air Force Base, Ohio. NASA's present Super Guppy Turbine, the fourth and last example of the final version, first flew in its outsized form in 1980. It and its three sister ships were built in the 1970s for Europe's Airbus Industrie to ferry outsized structures for Airbus jetliners to the final assembly plant in Toulouse, France. It later was acquired by the European Space Agency, and then acquired by NASA in late 1997 for transport of large structures for the International Space Station to the launch site. It replaced the earlier-model Super Guppy, which has been retired and is used for spare parts. NASA's Super Guppy Turbine carries NASA registration number N941NA, and is based at Ellington Field near the Johnson Space Center. For more information on NASA's Super Guppy Turbine, log onto the Johnson Space Center Super Guppy web page at http://spaceflight.nasa.gov/station/assembly/superguppy/

Pressure retarded osmosis as a controlling system for traditional renewables

NASA Astrophysics Data System (ADS)

Carravetta, Armando; Fecarotta, Oreste; La Rocca, Michele; Martino, Riccardo

2015-04-01

Pressure retarded osmosis (PRO) is a viable but still not diffused form of renewable energy (see Maisonneuve et al., 2015 for a recent literature review). In PRO, water from a low salinity feed solution permeates through a membrane into a pressurized, high salinity draw solution, giving rise to a positive pressure drop; then energy is obtained by depressurizing the permeate through a hydro-turbine and brackish water is discharged. Many technological, environmental and economical aspects are obstacles in the diffusion of PRO, like the vulnerability of the membranes to fouling, the impact of the brackish water on the local marine environment, the high cost of membranes, etc. We are interested in the use of PRO as a combined form of energy with other renewable energy source like solar, wind or mini hydro in water supply networks (WSN). For the wide diffusion of renewables one of the major concerns of commercial power companies is to obtain very stable form of energy to comply with prescriptions of electricity grid operators and with the instant energy demand curve. Renewables are generally very variable form of energy, for the influence of climatic conditions on available power, and of the fluctuation in water demand in WSN. PRO is a very flexible technology where with appropriate turbines and control system power can be varied continuously to compensate for variation of other source of energy. Therefore, PRO is suitable to be used as a balancing system for commercial power system. We will present a simulation of the performance of a PRO used in combination with three different renewables. In the first two scenarios PRO compensate the difference between energy demand and energy production of a solar power plant and hydro power plant in a WSN. In the third scenario PRO is used to compensate daily variation of energy production in a wind power plant. Standard curves of energy production and energy demand for southern Italy are used. In order to control PRO production an appropriate hydro turbine system is necessary. Therefore, pumps as turbine (PAT) are used in alternative to a classical hydraulic turbine (Carravetta et al., 2013). PAT can be easily regulated by hydraulic system, of by an inverter, granting the necessary flexibility of energy production with a sensible reduction of machinery cost. Maisonneuve J, Pillay P, Laflamme C.B. Pressure-retarded osmotic power system model considering non-ideal effects. Renewable Energy. 2015; 75(3): 416-424. Carravetta A, Del Giudice G, Fecarotta O, Ramos HM. Pump as Turbine (PAT) Design in Water Distribution Network by System Effectiveness. Water. 2013; 5(3):1211-1225.

Turbine Engine Disk Rotor Health Monitoring Assessment Using Spin Tests Data

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali; Woike, Mark; Baalini, George; Bodis, James R.

2012-01-01

Detecting rotating engine component malfunctions and structural anomalies is increasingly becoming a crucial key feature that will help boost safety and lower maintenance cost. However, achievement of such technology, which can be referred to as a health monitoring remains somewhat challenging to implement. This is mostly due to presence of scattered loading conditions, crack sizes, component geometry and material properties that hinders the simplicity of imposing such application. Different approaches are being considered to assist in developing other means of health monitoring or nondestructive techniques to detect hidden flaws and mini cracks before any catastrophic events occur. These methods extend further to assess material discontinuities and other defects that have matured to the level where a failure is very likely. This paper is focused on presenting data obtained from spin test experiments of a turbine engine like rotor disk and their correlation to the development of a structural health monitoring and fault detection system. The data collected includes blade tip clearance, blade tip timing measurements and shaft displacements. The experimental results are collected at rotational speeds up to 10,000 Rpm and tests are conducted at the NASA Glenn Research Center s Rotordynamics Laboratory via a high precision spin system. Additionally, this study offers a closer glance at a selective online evaluation of a rotating disk using advanced capacitive, microwave and eddy current sensor technology.

Turbine engine disk rotor health monitoring assessment using spin tests data

NASA Astrophysics Data System (ADS)

Abdul-Aziz, Ali; Woike, Mark; Baaklini, George; Bodis, James R.

2012-04-01

Detecting rotating engine component malfunctions and structural anomalies is increasingly becoming a crucial key feature that will help boost safety and lower maintenance cost. However, achievement of such technology, which can be referred to as a health monitoring remains somewhat challenging to implement. This is mostly due to presence of scattered loading conditions, crack sizes, component geometry and material properties that hinders the simplicity of imposing such application. Different approaches are being considered to assist in developing other means of health monitoring or nondestructive techniques to detect hidden flaws and mini cracks before any catastrophic events occur. These methods extend further to assess material discontinuities and other defects that have matured to the level where a failure is very likely. This paper is focused on presenting data obtained from spin test experiments of a turbine engine like rotor disk and their correlation to the development of a structural health monitoring and fault detection system. The data collected includes blade tip clearance, blade tip timing measurements and shaft displacements. The experimental results are collected at rotational speeds up to 10,000 Rpm and tests are conducted at the NASA Glenn Research Center's Rotordynamics Laboratory via a high precision spin system. Additionally, this study offers a closer glance at a selective online evaluation of a rotating disk using advanced capacitive, microwave and eddy current sensor technology.

Mini Solar and Sea Current Power Generation System

NASA Astrophysics Data System (ADS)

Almenhali, Abdulrahman; Alshamsi, Hatem; Aljunaibi, Yaser; Almussabi, Dheyab; Alshehhi, Ahmed; Hilal, Hassan Bu

2017-07-01

The power demand in United Arab Emirates is increased so that there is a consistent power cut in our region. This is because of high power consumption by factories and also due to less availability of conventional energy resources. Electricity is most needed facility for the human being. All the conventional energy resources are depleting day by day. So we have to shift from conventional to non-conventional energy resources. In this the combination of two energy resources is takes place i.e. wind and solar energy. This process reviles the sustainable energy resources without damaging the nature. We can give uninterrupted power by using hybrid energy system. Basically this system involves the integration of two energy system that will give continuous power. Solar panels are used for converting solar energy and wind turbines are used for converting wind energy into electricity. This electrical power can utilize for various purpose. Generation of electricity will be takes place at affordable cost. This paper deals with the generation of electricity by using two sources combine which leads to generate electricity with affordable cost without damaging the nature balance. The purpose of this project was to design a portable and low cost power system that combines both sea current electric turbine and solar electric technologies. This system will be designed in efforts to develop a power solution for remote locations or use it as another source of green power.

Anomaly Detection Techniques with Real Test Data from a Spinning Turbine Engine-Like Rotor

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali; Woike, Mark R.; Oza, Nikunj C.; Matthews, Bryan L.

2012-01-01

Online detection techniques to monitor the health of rotating engine components are becoming increasingly attractive to aircraft engine manufacturers in order to increase safety of operation and lower maintenance costs. Health monitoring remains a challenge to easily implement, especially in the presence of scattered loading conditions, crack size, component geometry, and materials properties. The current trend, however, is to utilize noninvasive types of health monitoring or nondestructive techniques to detect hidden flaws and mini-cracks before any catastrophic event occurs. These techniques go further to evaluate material discontinuities and other anomalies that have grown to the level of critical defects that can lead to failure. Generally, health monitoring is highly dependent on sensor systems capable of performing in various engine environmental conditions and able to transmit a signal upon a predetermined crack length, while acting in a neutral form upon the overall performance of the engine system.

Optimal area of lateral mass mini-screws implanted in plated cervical laminoplasty: a radiography anatomy study.

PubMed

Chen, Hua; Li, Huibo; Deng, Yuxiao; Rong, Xin; Gong, Quan; Li, Tao; Song, Yueming; Liu, Hao

2017-04-01

Lateral mass mini-screws used in plated cervical laminoplasty might penetrate into facet joints. The objective is to observe this complication incidence and to identify the optimal areas for 5- and 7-mm-long mini-screws to implant on lateral mass. 47 patients who underwent plated cervical laminoplasty were included. The optimal area for mini-screws implanting was set according to pre-operative 3D CT reconstruction data. Then, each posterior-lateral mass surface was divided into three regions: 7-mm region, 5-mm region, and dangerous area. The mini-screw implanted region was recorded. Post-operative CT images were used to identify whether the mini-screws penetrated into facet joints. 235 mini-plates and 470 lateral mass mini-screws were used in the study. 117 (24.9%) mini-screws penetrated 88 (37.4%) facet joints. The 5-mm-long mini-screw optimal area occupied the upper 72, 65, 65, 64, and 65 % area of the posterior-lateral mass surface for C3-7, while the 7-mm-long mini-screw optimal area encompassed the upper 54, 39, 40, 33, and 32 %. Only 7-mm-long mini-screws were used to fix the plate to the lateral mass. 4 of 240 mini-screws in 7-mm region, 67 of the 179 mini-screws in 5-mm region, and 46 of the 51 mini-screws in dangerous region penetrated into the facet joint. The differences in the rate of facet joint penetration related to region were statistically significant (P < 0.001). The facet joint destruction by mini-screws was not a rare complication in plated cervical laminoplasty. The optimal areas we proposed may help guide the mini-screw implantation positions.

Lateral forces exerted through ball or bar attachments in relation to the inclination of mini-implant underneath overdentures: in vitro study.

PubMed

Takagaki, Kyozo; Gonda, Tomoya; Maeda, Yoshinobu

2015-09-01

Lateral force to mini-implants should be avoided because mini-implants are weak mechanically because of its small diameter. Overdentures retained by mini-implants are usually formed using ball attachments. However, bar attachments can offer the advantage of splinting the mini-implants. This study examined the effect of attachments in withstanding these lateral forces in tilted mini-implants of overdentures. Strain gauges were attached to the mini-implants (2.5 × 18 mm) embedded in an acrylic resin block. Two mini-implants were inserted vertically (Control) or with one mini-implant inclined at 10° or 20° (10-inclined and 20-inclined, respectively). The female portions of the attachments were secured to the denture base. A prefabricated ball attachment and CAD/CAM-fabricated bar attachment were compared. A vertical load of 49 N was applied to the occlusal surface at a distance 10 mm away from the center of two mini-implants. The lateral force borne by the mini-implants was measured via the attached strain gauge. Mann-Whitney U-test and an analysis of Bonferroni correction were used to compare differences between the two attachments and among the three models (P < 0.05). The lateral force exerted to the inclined mini-implant was significantly greater than that borne by a vertical mini-implant for both attachment types. The lateral force on the 20° inclined mini-implants with bar attachments was smaller than that on mini-implants with ball attachments. Inclined mini-implants are subjected to greater stresses than vertical ones, and a bar attachment can reduce the lateral forces borne by the mini-implant when one mini-implant inclined at 20°. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mini-Laparoscopy: Instruments and Economics.

PubMed

Shadduck, Phillip P; Paquentin, Eduardo Moreno; Carvalho, Gustavo L; Redan, Jay A

2015-11-01

Mini-laparoscopy (Mini) was pioneered more than 20 years ago, initially with instruments borrowed from other specialties and subsequently with tools designed specifically for Mini. Early adoption of Mini was inhibited though by the limitations of these first-generation instruments, especially functionality and durability. Newer generation Mini instruments have recently become available with improved effector tips, a choice of shaft diameters and lengths, better shaft insulation and electrosurgery capability, improved shaft strength and rotation, more ergonomic handles, low-friction trocar options, and improved instrument durability. Improvements are also occurring in imaging and advanced energy for Mini. The current status of mini-laparoscopy instruments and economics are presented.

Nanostructured severe plastic deformation processed titanium for orthodontic mini-implants.

PubMed

Serra, Glaucio; Morais, Liliane; Elias, Carlos Nelson; Semenova, Irina P; Valiev, Ruslan; Salimgareeva, Gulnaz; Pithon, Matheus; Lacerda, Rogério

2013-10-01

Titanium mini-implants have been successfully used as anchorage devices in Orthodontics. Commercially pure titanium (cpTi) was recently replaced by Ti-6Al-4V alloy as the mini-implant material base due to the higher strength properties of the alloy. However, the lower corrosion resistance and the lower biocompatibility have been lowering the success rate of Ti-6Al-4V mini-implants. Nanostructured titanium (nTi) is commercially pure titanium that was nanostructured by a specific technique of severe plastic deformation. It is bioinert, does not contain potentially toxic or allergic additives, and has higher specific strength properties than any other titanium applied in medical implants. The higher strength properties associated to the higher biocompatibility make nTi potentially useful for orthodontic mini-implant applications, theoretically overcoming cpTi and Ti-6Al-4V mini-implants. The purposes of the this work were to process nTi, to mechanically compare cpTi, Ti-6Al-4V, and nTi mini-implants by torque test, and to evaluate both the surface morphology and the fracture surface characteristics of them by SEM. Torque test results showed significant increase in the maximum torque resistance of nTi mini-implants when compared to cpTi mini-implants, and no statistical difference between Ti-6Al-4V and nTi mini-implants. SEM analysis demonstrated smooth surface morphology and transgranular fracture aspect for nTi mini-implants. Since nanostructured titanium mini-implants have mechanical properties comparable to titanium alloy mini-implants, and biocompatibility comparable to commercially pure titanium mini-implants, it is suggestive that nanostructured titanium can replace Ti-6Al-4V alloy as the material base for mini-implants. Copyright © 2013 Elsevier B.V. All rights reserved.

miniTri Mantevo miniapp v. 1.0

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

Berry, Johathan; Stark, Dylan; Wolf, Michael

2016-02-02

miniTri is a miniapplication developed as part of the Mantevo project. Given a graph, miniTri enumerates all triangles in this graph and computes a metric for each triangle based on the triangle edge and vertex degree. The output of miniTri is a summary of this metric. miniTri mimics the computational requirements of an important set of data science applications. Several approaches to this problem are included in the miniTri software.

Internal Structure of Mini-CEX Scores for Internal Medicine Residents: Factor Analysis and Generalizability

ERIC Educational Resources Information Center

Cook, David A.; Beckman, Thomas J.; Mandrekar, Jayawant N.; Pankratz, V. Shane

2010-01-01

The mini-CEX is widely used to rate directly observed resident-patient encounters. Although several studies have explored the reliability of mini-CEX scores, the dimensionality of mini-CEX scores is incompletely understood. Objective: Explore the dimensionality of mini-CEX scores through factor analysis and generalizability analysis. Design:…

Engine rotor health monitoring: an experimental approach to fault detection and durability assessment

NASA Astrophysics Data System (ADS)

Abdul-Aziz, Ali; Woike, Mark R.; Clem, Michelle; Baaklini, George

2015-03-01

Efforts to update and improve turbine engine components in meeting flights safety and durability requirements are commitments that engine manufacturers try to continuously fulfill. Most of their concerns and developments energies focus on the rotating components as rotor disks. These components typically undergo rigorous operating conditions and are subject to high centrifugal loadings which subject them to various failure mechanisms. Thus, developing highly advanced health monitoring technology to screen their efficacy and performance is very essential to their prolonged service life and operational success. Nondestructive evaluation techniques are among the many screening methods that presently are being used to pre-detect hidden flaws and mini cracks prior to any appalling events occurrence. Most of these methods or procedures are confined to evaluating material's discontinuities and other defects that have mature to a point where failure is eminent. Hence, development of more robust techniques to pre-predict faults prior to any catastrophic events in these components is highly vital. This paper is focused on presenting research activities covering the ongoing research efforts at NASA Glenn Research Center (GRC) rotor dynamics laboratory in support of developing a fault detection system for key critical turbine engine components. Data obtained from spin test experiments of a rotor disk that relates to investigating behavior of blade tip clearance, tip timing and shaft displacement based on measured data acquired from sensor devices such as eddy current, capacitive and microwave are presented. Additional results linking test data with finite element modeling to characterize the structural durability of a cracked rotor as it relays to the experimental tests and findings is also presented. An obvious difference in the vibration response is shown between the notched and the baseline no notch rotor disk indicating the presence of some type of irregularity.

A Mini-review on the Effect of Mini-implants on Contemporary Orthodontic Science

PubMed Central

Nosouhian, Saeid; Rismanchian, Mansour; Sabzian, Roya; Shadmehr, Elham; Badrian, Hamid; Davoudi, Amin

2015-01-01

The purpose of this literature review was to screen the valuable published articles regarding to the impacts of mini-implants on orthodontic science, briefly. The searching category was performed on the Pubmed using MeSH words such as “dental (mini) implants, orthodontic anchorage procedures, and orthodontic appliances.” After preliminary sketch, they were grouped as follow: Those evaluating (a) common appliances for providing orthodontic anchorage, (b) biomechanical details of mini-implants and their insertion, (c) clinical application of mini-implants for orthognathic treatments, (d) limitations and possible complications. In conclusion, mini-implant evolved the orthodontic treatment plans and compromised the required orthognathic surgery. Malocclusion treatment and pure orthodontic or orthopedic movements in the three-dimensions have become recently possible by using mini-implant to provide skeletal anchorage. PMID:26225113

Quasi-periodic Behavior of Mini-disks in Binary Black Holes Approaching Merger

NASA Astrophysics Data System (ADS)

Bowen, Dennis B.; Mewes, Vassilios; Campanelli, Manuela; Noble, Scott C.; Krolik, Julian H.; Zilhão, Miguel

2018-01-01

We present the first magnetohydrodynamic simulation in which a circumbinary disk around a relativistic binary black hole feeds mass to individual accretion disks (“mini-disks”) around each black hole. Mass flow through the accretion streams linking the circumbinary disk to the mini-disks is modulated quasi-periodically by the streams’ interaction with a nonlinear m = 1 density feature, or “lump,” at the inner edge of the circumbinary disk: the stream supplying each mini-disk comes into phase with the lump at a frequency 0.74 times the binary orbital frequency. Because the binary is relativistic, the tidal truncation radii of the mini-disks are not much larger than their innermost stable circular orbits; consequently, the mini-disks’ inflow times are shorter than the conventional estimate and are comparable to the stream modulation period. As a result, the mini-disks are always in inflow disequilibrium, with their masses and spiral density wave structures responding to the stream’s quasi-periodic modulation. The fluctuations in each mini-disk’s mass are so large that as much as 75% of the total mini-disk mass can be contained within a single mini-disk. Such quasi-periodic modulation of the mini-disk structure may introduce distinctive time-dependent features in the binary’s electromagnetic emission.

Superficial venous incompetence: low-cost outpatient minisurgery, sclerotherapy and combined procedure as a management plan. Costs and efficacy. A 20-year, follow-up registry.

PubMed

Belcaro, Gianni; Dugall, Mark; Corsi, Marcello; Agus, Giovanni B; Ippolito, Edmondo

2016-08-01

This registry study evaluated low-cost outpatient surgery (mini-S) for venous insufficiency as an alternative to stripping. This 20-year follow-up is focused on the recurrence of varices and on the long-term efficacy of the mini-S (group 1) in comparison with controls (2, stripping), sclerotherapy (3) or a combination of mini-S+sclerotherapy (4). Costs were compared. At 20-years of follow-up, considering recurrence/development of new varicose veins, 24.05% of the limbs treated with mini-S developed new varices in comparison with 64.4% in group 2, 24.1% in group 3 and 15.4% in group 4 (P<0.05). New surgical procedures were needed in 18.9% of mini-S patients vs. 58.5% in group 2, 21.9% in group 3 and 19.7% in group 4 (P<0.05 between group 2 and the other groups). Sclerotherapy (in the years following the initial treatment) was used in 37.9% of mini-S patients in comparison with 67.7% of subjects in group 2 patients, 33.1% in group 3 and 22.8% in group 4 (P<0.05 between outpatient treatment and group 2). The superficial venous system was incompetent in 21% of mini-S patients in comparison with 38.8% in group 2 (P<0.05), 20.7% in group 3 and 17.9% of group 4. At 20 years edema was present in 10.5% of limbs in group 2 in comparison with a <3% (range 2.2-2.1%) in the other groups. Edema was more significant after stripping. Ambulatory venous pressure measurements in subgroups was lower in groups 1, 3 and 4 with a lower refilling time (P<0.05). The cost of in-hospital, daily surgical treatments were €1978 (covered by the heathcare provider). The cost of mini-S was on average €488 per limb (covered by patients). Outpatients procedures, in particular the mini-S management plan, were cheaper than stripping and more effective at 20-years follow-up. They could be a model for emerging contries with restricted budgets for vein surgery. Also being cheaper more people may have benefits from treatment when/where hospital procedures are not covered by an healthcare provider.

Failure rates of mini-implants placed in the infrazygomatic region.

PubMed

Uribe, Flavio; Mehr, Rana; Mathur, Ajay; Janakiraman, Nandakumar; Allareddy, Veerasathpurush

2015-01-01

The purpose of this pilot study was to evaluate the failure rates of mini-implants placed in the infrazygomatic region and to evaluate factors that affect their stability. A retrospective cohort study of 30 consecutive patients (55 mini-implants) who had infrazygomatic mini-implants at a University Clinic were evaluated for failure rates. Patient, mini-implant, orthodontic, surgical, and mini-implant maintenance factors were evaluated by univariate logistic regression models for association to failure rates. A 21.8 % failure rate of mini-implants placed in the infazygomatic region was observed. None of the predictor variables were significantly associated with higher or lower odds for failed implants. Failure rates for infrazygomatic mini-implants were slightly higher than those reported in other maxilla-mandibular osseous locations. No predictor variables were found to be associated to the failure rates.

Comparison of success rates of orthodontic mini-screws by the insertion method.

PubMed

Kim, Jung Suk; Choi, Seong Hwan; Cha, Sang Kwon; Kim, Jang Han; Lee, Hwa Jin; Yeom, Sang Seon; Hwang, Chung Ju

2012-10-01

The aim of this study was to compare the success rates of the manual and motor-driven mini-screw insertion methods according to age, gender, length of mini-screws, and insertion sites. We retrospectively reviewed 429 orthodontic mini-screw placements in 286 patients (102 in men and 327 in women) between 2005 and 2010 at private practice. Age, gender, mini-screw length, and insertion site were cross-tabulated against the insertion methods. The Cochran-Mantel-Haenszel test was performed to compare the success rates of the 2 insertion methods. The motor-driven method was used for 228 mini-screws and the manual method for the remaining 201 mini-screws. The success rates were similar in both men and women irrespective of the insertion method used. With respect to mini-screw length, no difference in success rates was found between motor and hand drivers for the 6-mm-long mini-screws (68.1% and 69.5% with the engine driver and hand driver, respectively). However, the 8-mm-long mini-screws exhibited significantly higher success rates (90.4%, p < 0.01) than did the 6-mm-long mini-screws when placed with the engine driver. The overall success rate was also significantly higher in the maxilla (p < 0.05) when the engine driver was used. Success rates were similar among all age groups regardless of the insertion method used. Taken together, the motor-driven insertion method can be helpful to get a higher success rate of orthodontic mini-screw placement.

DOE/NREL supported wind energy activities in Indonesia

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

Drouilhet, S.

1997-12-01

This paper describes three wind energy related projects which are underway in Indonesia. The first is a USAID/Winrock Wind for Island and Nongovernmental Development (WIND) project. The objectives of this project are to train local nongovernmental organizations (NGOs) in the siting, installation, operation, and maintenance of small wind turbines. Then to install up to 20 wind systems to provide electric power for productive end uses while creating micro-enterprises which will generate enough revenue to sustain the wind energy systems. The second project is a joint Community Power Corporation/PLN (Indonesian National Electric Utility) case study of hybrid power systems in villagemore » settings. The objective is to evaluate the economic viability of various hybrid power options for several different situations involving wind/photovoltaics/batteries/diesel. The third project is a World Bank/PLN preliminary market assessment for wind/diesel hybrid systems. The objective is to estimate the size of the total potential market for wind/diesel hybrid power systems in Indonesia. The study will examine both wind retrofits to existing diesel mini-grids and new wind-diesel plants in currently unelectrified villages.« less

Production of extended release mini-tablets using directly compressible grades of HPMC.

PubMed

Mohamed, Faiezah A A; Roberts, Matthew; Seton, Linda; Ford, James L; Levina, Marina; Rajabi-Siahboomi, Ali R

2013-11-01

Hypromellose (HPMC) has been previously used to control drug release from mini-tablets. However, owing to poor flow, production of mini-tablets containing high HPMC levels is challenging. Directly compressible (DC) HPMC grades have been developed by Dow Chemical Company. To compare the properties of HPMC DC (METHOCEL™ K4M and K100M) with regular (REG) HPMC grades. Particle size distribution and flowability of HPMC REG and DC were evaluated. 3 mm mini-tablets, containing hydrocortisone or theophylline as model drugs and 40% w/w HPMC DC or REG were produced. Mini-tablets containing HPMC DC grades were manufactured using a rotary press simulator at forces between 2-4 kN and speeds of 5, 10, 15 or 20 rpm. Mini-tablets containing HPMC REG were produced manually. The improved flowability of HPMC DC grades, which have a narrower particle size distribution and larger particle sizes, meant that simulated large scale production of mini-tablets with good weight uniformity (CV 1.79-4.65%) was feasible. It was not possible to automatically manufacture mini-tablets containing HPMC REG due to the poor flowability of the formulations. Drug release from mini-tablets comprising HPMC DC and REG were comparable. Mini-tablets containing HPMC DC illustrated a higher tensile strength compared to mini-tablets made with HPMC REG. Mini-tablets produced with HPMC DC at different compression speeds had similar drug release profiles. Production of extended release mini-tablets was successfully achieved when HPMC DC was used. Drug release rate was not influenced by the different HPMC DC grades (K4M or K100M) or production speed.

Contrasting influences of Drosophila white/mini-white on ethanol sensitivity in two different behavioral assays

PubMed Central

Chan, Robin F.; Lewellyn, Lara; DeLoyht, Jacqueline M.; Sennett, Kristyn; Coffman, Scarlett; Hewitt, Matthew; Bettinger, Jill C.; Warrick, John M.; Grotewiel, Mike

2014-01-01

Background The fruit fly Drosophila melanogaster has been used extensively to investigate genetic mechanisms of ethanol-related behaviors. Many past studies in flies, including studies from our laboratory, have manipulated gene expression using transposons carrying the genetic-phenotypic marker mini-white, a derivative of the endogenous gene white. Whether the mini-white transgenic marker or the endogenous white gene influence behavioral responses to acute ethanol exposure in flies has not been systematically investigated. Methods We manipulated mini-white and white expression via (i) transposons marked with mini-white, (ii) RNAi against mini-white and white and (iii) a null allele of white. We assessed ethanol sensitivity and tolerance using a previously described eRING assay (based on climbing in the presence of ethanol) and an assay based on ethanol-induced sedation. Results In eRING assays, ethanol-induced impairment of climbing correlated inversely with expression of the mini-white marker from a series of transposon insertions. Additionally, flies harboring a null allele of white or flies with RNAi-mediated knockdown of mini-white were significantly more sensitive to ethanol in eRING assays than controls expressing endogenous white or the mini-white marker. In contrast, ethanol sensitivity and rapid tolerance measured in the ethanol sedation assay were not affected by decreased expression of mini-white or endogenous white in flies. Conclusions Ethanol sensitivity measured in the eRING assay is noticeably influenced by white and mini-white, making eRING problematic for studies on ethanol-related behavior in Drosophila using transgenes marked with mini-white. In contrast, the ethanol sedation assay described here is a suitable behavioral paradigm for studies on ethanol sedation and rapid tolerance in Drosophila including those that use widely available transgenes marked with mini-white. PMID:24890118

Replacing a failed mini-implant with a miniplate to prevent interruption during orthodontic treatment.

PubMed

Lee, Jin-Hwa; Choo, Hyeran; Kim, Seong-Hun; Chung, Kyu-Rhim; Giannuzzi, Lucille A; Ngan, Peter

2011-06-01

When mini-implants fail during orthodontic treatment, there is a need to have a backup plan to either replace the failed implant in the adjacent interradicular area or wait for the bone to heal before replacing the mini-implant. We propose a novel way to overcome this problem by replacement with a miniplate so as not to interrupt treatment or prolong treatment time. The indications, advantages, efficacy, and procedures for switching from a mini-implant to a miniplate are discussed. Two patients who required replacement of failed mini-implants are presented. In the first patient, because of the proximity of the buccal vestibule to the mini-implant, it was decided to replace the failed mini-implant by an I-shaped C-tube miniplate. In the second patient, radiolucencies were found around the failed mini-implants, making the adjacent alveolar bone unavailable for immediate placement of another mini-implant. In addition, the maxillary sinus pneumatization was expanded deeply into the interradicular spaces; this further mandated an alternative placement site. One failed mini-implant was examined under a scanning electron microscope for bone attachment. Treatment was completed in both patients after replacement with miniplates without interrupting the treatment mechanics or prolonging the treatments. Examination under the scanning electron microscope showed partial bone growth into the coating pores and titanium substrate interface even after thorough cleaning and sterilization. Replacement with a miniplate is a viable solution for failed mini-implants during orthodontic treatment. The results from microscopic evaluation of the failed mini-implant suggest that stringent guidelines are needed for recycling used mini-implants. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

A cross-sectional study on schistosomiasis and soil-transmitted helminths in Mbita district, western Kenya using different copromicroscopic techniques.

PubMed

Ng'etich, Annette I; Rawago, Fredrick O; Jura, Walter G Z O; Mwinzi, Pauline N; Won, Kimberly Y; Odiere, Maurice R

2016-02-16

Identification of populations to be targeted for individual treatment and broad-spectrum therapy in schistosomiasis-endemic areas, assessment of therapy efficacy, morbidity, and evaluation of control strategies need to be based on reliable diagnostic tools. Kato-Katz is routinely used and remains the standard diagnostic technique for schistosomiasis, despite its many challenges. This study was conducted in Nyamanga village, Mbita, western Kenya, and evaluated the diagnostic performance of Kato-Katz, Mini-Parasep and modified Mini-FLOTAC techniques in detection of Schistosoma mansoni and soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura and hookworm) ova. Stool samples from 132 individuals were screened for eggs of S. mansoni by the 3 techniques. Mini-Parasep faecal parasite concentrator (Apacor Ltd, England), a single-use diagnostic device with a built-in filter for faecal concentration of helminth eggs by sedimentation was employed on stool samples fixed in 10% formalin. A modified Mini-FLOTAC (University of Naples, Italy) was based on floatation of helminths eggs with two different solutions (FS2 and FS7) using a closed system (Fill-FLOTAC) with 5% formalin. Kato-Katz was performed following WHO recommendation. Prevalence of S. mansoni and STH, sensitivity and degree of agreement among the 3 techniques were determined. Prevalence of S. mansoni was 47.0%, 34.1% and 20.5% by Mini-Parasep, Kato-Katz and modified Mini-FLOTAC FS7 techniques, respectively. Prevalence of any STH infection was 6.1%, 3.0%, 6.1% and 6.8% by Mini-Parasep, Kato-Katz, modified Mini-FLOTAC FS2 and modified Mini-FLOTAC FS7 techniques, respectively. Considering the pooled results of the three methods (Mini-Parasep, Kato-Katz and modified Mini-FLOTAC FS7) as diagnostic 'gold' standard, the sensitivity of Mini-Parasep, Kato-Katz and modified Mini-FLOTAC FS7 for S. mansoni was 77.5%, 56.1%, and 33.8%, respectively. Mini-Parasep and modified Mini-FLOTAC FS7 techniques had moderate (κ = 0.46) and fairly good (κ = 0.25) agreements with Kato-Katz for S. mansoni, respectively. Mini-Parasep detected a higher proportion of light intensity S. mansoni infections compared to Kato-Katz, which detected high proportions of heavy infections. Mini-Parasep detected a similar mean number of S. mansoni eggs per gram (EPG) of stool compared to the standard Kato-Katz (62.9 vs 97.3; t (131) = -0.49, P = 0.6265) and significantly higher EPG compared to the modified Mini-FLOTAC FS7 (62.9 vs 34.6; t (131) = 5.39, P < 0.0001). The high sensitivity of Mini-Parasep suggests its promising potential as an alternative tool in enhancing diagnosis and in monitoring schistosomiasis transmission and determining endpoint of intervention programs, especially in low endemicity areas. Mini-Parasep is also easy to operate, safe and also permits work with fresh stool.

Contrasting influences of Drosophila white/mini-white on ethanol sensitivity in two different behavioral assays.

PubMed

Chan, Robin F; Lewellyn, Lara; DeLoyht, Jacqueline M; Sennett, Kristyn; Coffman, Scarlett; Hewitt, Matthew; Bettinger, Jill C; Warrick, John M; Grotewiel, Mike

2014-06-01

The fruit fly Drosophila melanogaster has been used extensively to investigate genetic mechanisms of ethanol (EtOH)-related behaviors. Many past studies in flies, including studies from our laboratory, have manipulated gene expression using transposons carrying the genetic-phenotypic marker mini-white(mini-w), a derivative of the endogenous gene white(w). Whether the mini-w transgenic marker or the endogenous w gene influences behavioral responses to acute EtOH exposure in flies has not been systematically investigated. We manipulated mini-w and w expression via (i) transposons marked with mini-w, (ii) RNAi against mini-w and w, and (iii) a null allele of w. We assessed EtOH sensitivity and tolerance using a previously described eRING assay (based on climbing in the presence of EtOH) and an assay based on EtOH-induced sedation. In eRING assays, EtOH-induced impairment of climbing correlated inversely with expression of the mini-w marker from a series of transposon insertions. Additionally, flies harboring a null allele of w or flies with RNAi-mediated knockdown of mini-w were significantly more sensitive to EtOH in eRING assays than controls expressing endogenous w or the mini-w marker. In contrast, EtOH sensitivity and rapid tolerance measured in the EtOH sedation assay were not affected by decreased expression of mini-w or endogenous w in flies. EtOH sensitivity measured in the eRING assay is noticeably influenced by w and mini-w, making eRING problematic for studies on EtOH-related behavior in Drosophila using transgenes marked with mini-w. In contrast, the EtOH sensitivity assay described here is a suitable behavioral paradigm for studies on EtOH sensitivity and rapid tolerance in Drosophila including those that use widely available transgenes marked with mini-w. Copyright © 2014 by the Research Society on Alcoholism.

Equilibrium Partitioning Sediment Guidelines (ESGs) for the ...

EPA Pesticide Factsheets

... PLC = partial life-cycle ... 5 ii mini iiiiiiiii iiiiiii mi 1 1 iii mini ii i B : - Benthic vs WQC i— w ~_ ~ _ o° _ -0 ° - - - ii mini iiiiiiiii iiiiiii iiiiiiiii mini ii 0.1 ... PhD thesis. ...

Critical Structural and Functional Roles for the N-Terminal Insertion Sequence in Surfactant Protein B Analogs

PubMed Central

Walther, Frans J.; Waring, Alan J.; Hernandez-Juviel, Jose M.; Gordon, Larry M.; Wang, Zhengdong; Jung, Chun-Ling; Ruchala, Piotr; Clark, Andrew P.; Smith, Wesley M.; Sharma, Shantanu; Notter, Robert H.

2010-01-01

Background Surfactant protein B (SP-B; 79 residues) belongs to the saposin protein superfamily, and plays functional roles in lung surfactant. The disulfide cross-linked, N- and C-terminal domains of SP-B have been theoretically predicted to fold as charged, amphipathic helices, suggesting their participation in surfactant activities. Earlier structural studies with Mini-B, a disulfide-linked construct based on the N- and C-terminal regions of SP-B (i.e., ∼residues 8–25 and 63–78), confirmed that these neighboring domains are helical; moreover, Mini-B retains critical in vitro and in vivo surfactant functions of the native protein. Here, we perform similar analyses on a Super Mini-B construct that has native SP-B residues (1–7) attached to the N-terminus of Mini-B, to test whether the N-terminal sequence is also involved in surfactant activity. Methodology/Results FTIR spectra of Mini-B and Super Mini-B in either lipids or lipid-mimics indicated that these peptides share similar conformations, with primary α-helix and secondary β-sheet and loop-turns. Gel electrophoresis demonstrated that Super Mini-B was dimeric in SDS detergent-polyacrylamide, while Mini-B was monomeric. Surface plasmon resonance (SPR), predictive aggregation algorithms, and molecular dynamics (MD) and docking simulations further suggested a preliminary model for dimeric Super Mini-B, in which monomers self-associate to form a dimer peptide with a “saposin-like” fold. Similar to native SP-B, both Mini-B and Super Mini-B exhibit in vitro activity with spread films showing near-zero minimum surface tension during cycling using captive bubble surfactometry. In vivo, Super Mini-B demonstrates oxygenation and dynamic compliance that are greater than Mini-B and compare favorably to full-length SP-B. Conclusion Super Mini-B shows enhanced surfactant activity, probably due to the self-assembly of monomer peptide into dimer Super Mini-B that mimics the functions and putative structure of native SP-B. PMID:20084172

Psychometric properties of a sign language version of the Mini International Neuropsychiatric Interview (MINI).

PubMed

Øhre, Beate; Saltnes, Hege; von Tetzchner, Stephen; Falkum, Erik

2014-05-22

There is a need for psychiatric assessment instruments that enable reliable diagnoses in persons with hearing loss who have sign language as their primary language. The objective of this study was to assess the validity of the Norwegian Sign Language (NSL) version of the Mini International Neuropsychiatric Interview (MINI). The MINI was translated into NSL. Forty-one signing patients consecutively referred to two specialised psychiatric units were assessed with a diagnostic interview by clinical experts and with the MINI. Inter-rater reliability was assessed with Cohen's kappa and "observed agreement". There was 65% agreement between MINI diagnoses and clinical expert diagnoses. Kappa values indicated fair to moderate agreement, and observed agreement was above 76% for all diagnoses. The MINI diagnosed more co-morbid conditions than did the clinical expert interview (mean diagnoses: 1.9 versus 1.2). Kappa values indicated moderate to substantial agreement, and "observed agreement" was above 88%. The NSL version performs similarly to other MINI versions and demonstrates adequate reliability and validity as a diagnostic instrument for assessing mental disorders in persons who have sign language as their primary and preferred language.

Reasons for mini-implants failure: choosing installation site should be valued!

PubMed Central

Consolaro, Alberto; Romano, Fábio Lourenço

2014-01-01

Mini-implant loss is often associated with physical and mechanical aspects that result from choosing an inappropriate placement site. It is worth highlighting that: a) Interdental alveolar bone crests are flexible and deformable. For this reason, they may not offer the ideal absolute anchorage. The more cervical the structures, the more delicate they are, thus offering less physical support for mini-implant placement; b) Alveolar bone crests of triangular shape are more deformable, whereas those of rectangular shape are more flexible; c) The bases of the alveolar processes of the maxilla and the mandible are not flexible, for this reason, they are more likely to receive mini-implants; d) The more cervical a mini-implant is placed, the higher the risk of loss; the more apical a mini-implant is placed, the better its prognosis will be; e) 3D evaluations play a major role in planning the use of mini-implants. Based on the aforementioned considerations, the hypotheses about mini-implant loss are as follows: 1) Deflection of maxillary and mandibular alveolar processes when mini-implants are more cervically placed; 2) Mini-implants placed too near the periodontal ligament, with normal intra-alveolar tooth movement; 3) Low bone density, low thickness and low alveolar bone volume; 4) Low alveolar cortical bone thickness; 5) Excessive pressure inducing trabecular bone microfracture; 6) Sites of higher anatomical weakness in the mandible and the maxilla; 7) Thicker gingival tissue not considered when choosing the mini-implant. PMID:24945511

Revisiting the stability of mini-implants used for orthodontic anchorage.

PubMed

Yao, Chung-Chen Jane; Chang, Hao-Hueng; Chang, Jenny Zwei-Chieng; Lai, Hsiang-Hua; Lu, Shao-Chun; Chen, Yi-Jane

2015-11-01

The aim of this study is to comprehensively analyze the potential factors affecting the failure rates of three types of mini-implants used for orthodontic anchorage. Data were collected on 727 mini-implants (miniplates, predrilled titanium miniscrews, and self-drilling stainless steel miniscrews) in 220 patients. The factors related to mini-implant failure were investigated using a Chi-square test for univariate analysis and a generalized estimating equation model for multivariate analysis. The failure rate for miniplates was significantly lower than for miniscrews. All types of mini-implants, especially the self-drilling stainless steel miniscrews, showed decreased stability if the previous implantation had failed. The stability of predrilled titanium miniscrews and self-drilling stainless steel miniscrews were comparable at the first implantation. However, the failure rate of stainless steel miniscrews increased at the second implantation. The univariate analysis showed that the following variables had a significant influence on the failure rates of mini-implants: age of patient, type of mini-implant, site of implantation, and characteristics of the soft tissue around the mini-implants. The generalized estimating equation analysis revealed that mini-implants with miniscrews used in patients younger than 35 years, subjected to orthodontic loading after 30 days and implanted on the alveolar bone ridge, have a significantly higher risk of failure. This study revealed that once the dental surgeon becomes familiar with the procedure, the stability of orthodontic mini-implants depends on the type of mini-implant, age of the patient, implantation site, and the healing time of the mini-implant. Miniplates are a more feasible anchorage system when miniscrews fail repeatedly. Copyright © 2014. Published by Elsevier B.V.

Psychometric Properties of the Mini-Social Phobia Inventory

PubMed Central

Seeley-Wait, Elizabeth; Rapee, Ronald M.

2009-01-01

Objective: Although a potentially useful measure, to date, there has been only one published test of the psychometric properties of the Mini-Social Phobia Inventory (Mini-SPIN). Therefore, the psychometric properties of the Mini-SPIN, a brief 3-item screen for social anxiety disorder, were examined. Method: Participants were 186 patients diagnosed with social anxiety disorder (DSM-IV criteria) attending a specialized anxiety disorders clinic for treatment, and 56 nonclinical participants were recruited to serve as comparisons. Participants were diagnosed using the Anxiety Disorders Interview Schedule for DSM-IV, and they also completed the Mini-SPIN, the Social Interaction Anxiety Scale (SIAS), and the Social Phobia Scale (SPS). Construct validity for the Mini-SPIN was assessed by its correlations with the SIAS and the SPS. Reliability, internal consistency, discriminant validity, and sensitivity to change were also examined, and receiver operating characteristic curve analysis was conducted to determine guidelines regarding cutoff scores for the Mini-SPIN. The study was conducted between April 1999 and December 2001. Results: Supporting findings from a previous study, strong support was found for the Mini-SPIN's ability to discriminate individuals with social anxiety disorder from those without the disorder. Receiver operating characteristic analysis revealed that using a cutoff score of 6 or greater (P < .001), the Mini-SPIN demonstrates excellent sensitivity, specificity, and positive and negative predictive values. Conclusions: Findings suggest that the Mini-SPIN is a reliable and valid instrument for screening social anxiety disorder in adults. Importantly, the use of the Mini-SPIN in primary care may be one way to address the underrecognition of social anxiety disorder in such settings. Due to the ease and brevity of the measure, it also shows potential for use in epidemiology. Given that this study has revealed the ability of the Mini-SPIN to reflect treatment change, the Mini-SPIN may also be considered for use in treatment outcome studies that specifically require minimal assessment. PMID:19956461

αA-Crystallin–Derived Mini-Chaperone Modulates Stability and Function of Cataract Causing αAG98R-Crystallin

PubMed Central

Raju, Murugesan; Santhoshkumar, Puttur; Sharma, K. Krishna

2012-01-01

Background A substitution mutation in human αA-crystallin (αAG98R) is associated with autosomal dominant cataract. The recombinant mutant αAG98R protein exhibits altered structure, substrate-dependent chaperone activity, impaired oligomer stability and aggregation on prolonged incubation at 37°C. Our previous studies have shown that αA-crystallin–derived mini-chaperone (DFVIFLDVKHFSPEDLTVK) functions like a molecular chaperone by suppressing the aggregation of denaturing proteins. The present study was undertaken to determine the effect of αA-crystallin–derived mini-chaperone on the stability and chaperone activity of αAG98R-crystallin. Methodology/Principal Findings Recombinant αAG98R was incubated in presence and absence of mini-chaperone and analyzed by chromatographic and spectrometric methods. Transmission electron microscope was used to examine the effect of mini-chaperone on the aggregation propensity of mutant protein. Mini-chaperone containing photoactive benzoylphenylalanine was used to confirm the interaction of mini-chaperone with αAG98R. The rescuing of chaperone activity in mutantα-crystallin (αAG98R) by mini-chaperone was confirmed by chaperone assays. We found that the addition of the mini-chaperone during incubation of αAG98R protected the mutant crystallin from forming larger aggregates that precipitate with time. The mini-chaperone-stabilized αAG98R displayed chaperone activity comparable to that of wild-type αA-crystallin. The complexes formed between mini-αA–αAG98R complex and ADH were more stable than the complexes formed between αAG98R and ADH. Western-blotting and mass spectrometry confirmed the binding of mini-chaperone to mutant crystallin. Conclusion/Significance These results demonstrate that mini-chaperone stabilizes the mutant αA-crystallin and modulates the chaperone activity of αAG98R. These findings aid in our understanding of how to design peptide chaperones that can be used to stabilize mutant αA-crystallins and preserve the chaperone function. PMID:22970163

Evaluation of fracture torque resistance of orthodontic mini-implants.

PubMed

Dalla Rosa, Fernando; Burmann, Paola Fp; Ruschel, Henrique C; Vargas, Ivana A; Kramer, Paulo F

2016-12-01

This study sought to assess the fracture torque resistance of mini-implants used for orthodontic anchorage. Five commercially available brands of mini-implants were used (SIN®, CONEXÃO®, NEODENT®, MORELLI®, andFORESTADENT®). Ten mini-implants of each diameter of each brand were tested, for a total 100 specimens. The mini-implants were subject to a static torsion test as described in ASTMstandard F543. Analysis of variance (ANOVA) with the Tukey multiple comparisons procedure was used to assess results. Overall, mean fracture strength ranged from 15.7 to 70.4 N·cm. Mini-implants with larger diameter exhibited higher peak torque values at fracture and higher yield strength, regardless of brand. In addition, significant differences across brands were observed when implants were stratified by diameter. In conclusion, larger mini-implant diameter is associated with increased fracture torque resistance. Additional information on peak torque values at fracture of different commercial brands of mini-implants may increase the success rate of this orthodontic anchorage modality. Sociedad Argentina de Investigación Odontológica.

Reliability and validity of the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID).

PubMed

Sheehan, David V; Sheehan, Kathy H; Shytle, R Douglas; Janavs, Juris; Bannon, Yvonne; Rogers, Jamison E; Milo, Karen M; Stock, Saundra L; Wilkinson, Berney

2010-03-01

To investigate the concurrent validity and reliability of the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID), a short structured diagnostic interview for DSM-IV and ICD-10 psychiatric disorders in children and adolescents. Participants were 226 children and adolescents (190 outpatients and 36 controls) aged 6 to 17 years. To assess the concurrent validity of the MINI-KID, participants were administered the MINI-KID and the Schedule for Affective Disorders and Schizophrenia for School Aged Children-Present and Lifetime Version (K-SADS-PL) by blinded interviewers in a counterbalanced order on the same day. Participants also completed a self-rated measure of disability. In addition, interrater (n = 57) and test-retest (n = 83) reliability data (retest interval, 1-5 days) were collected, and agreement between the parent version of the MINI-KID and the standard MINI-KID (n = 140) was assessed. Data were collected between March 2004 and January 2008. Substantial to excellent MINI-KID to K-SADS-PL concordance was found for syndromal diagnoses of any mood disorder, any anxiety disorder, any substance use disorder, any ADHD or behavioral disorder, and any eating disorder (area under curve [AUC] = 0.81-0.96, kappa = 0.56-0.87). Results were more variable for psychotic disorder (AUC = 0.94, kappa = 0.41). Sensitivity was substantial (0.61-1.00) for 15/20 individual DSM-IV disorders. Specificity was excellent (0.81-1.00) for 18 disorders and substantial (> 0.73) for the remaining 2. The MINI-KID identified a median of 3 disorders per subject compared to 2 on the K-SADS-PL and took two-thirds less time to administer (34 vs 103 minutes). Interrater and test-retest kappas were substantial to almost perfect (0.64-1.00) for all individual MINI-KID disorders except dysthymia. Concordance of the parent version (MINI-KID-P) with the standard MINI-KID was good. The MINI-KID generates reliable and valid psychiatric diagnoses for children and adolescents and does so in a third of the time as the K-SADS-PL. (c) 2010 Physicians Postgraduate Press, Inc.

Use of mini-refuges by female northern pintails wintering in southwestern Louisiana

USGS Publications Warehouse

Cox, Robert R.; Afton, Alan D.

1998-01-01

The Gulf Coast Joint Venture of the North American Waterfowl Management Plan began contracting private agricultural lands (hereafter mini-refuges) in 1988 to expand existing sanctuaries for northern pintails (Anas acuta) in southwestern Louisiana. Previous research suggested that mini-refuges may prove more attractive to pintails than permanent, open-water pools (pools) on refuges because mini-refuges provide sanctuary and food during the day, whereas pools generally provide only sanctuary (Rave and Cordes 1993). We used radiotelemetry to compare diel use of mini-refuges and pools (Lacassine Pool and Amoco Pool) by female pintails in southwestern Louisiana during winters of 1991-1992 and 1992-1993. We examined variation in use of these areas in relation to female age (immature or adult), time period (prehunting season, first hunting season, time between split hunting seasons, second hunting season, and posthunting season), and winter (1991-1992 and 1992-1993). Diurnal use of min-refuges and pools differed among time periods, but differences were not consistent between winters. Mini-refuges accounted for <2% of diurnal use by pintails in 7 of 10 time-period and winter comparisons. Diurnal use of mini-refuges was lower than that of Lacassine Pool in 8 of 10 time-period and winter comparisons. Diurnal use of mini-refuges was lower than tha of Amoco pool during first hunting season in 1992-1993, but use of these areas did not differ within other time periods and winters. Nocturnal use of mini-refuges and pools did not differ in relation to female age, time period, winter, or individual bird. Nocturnal use of mini-refuges did not differ from that of Lacassine Pool. In contrast to predictions and findings by Rave and Cordes (1993), we found that: (1) female pintails did not use mini-refuges more than pools, and (2) female pintails used mini-refuges at night. We believe that use of mini-refuges by pintails could be increased if mini-refuges were (1) located in areas of traditionally high pintail use, (2) increased in size, (3) flooded immediately prior to hunting season, and (4) cleared of dense vegetation by rolling, disking, or burning.

Ceramic blade attachment system

DOEpatents

Boyd, Gary L.

1995-01-01

A retainer ring is arranged to mount turbine blades to a turbine disk so that aerodynamic forces produced by a gas turbine engine are transferred from the turbine blades to the turbine disk to cause the turbine blades and turbine disk to rotate, but so that centrifugal forces of the turbine blades resulting from the rotation of the turbine blades and turbine disk are not transferred from the turbine blades to the turbine disk.

Mini-Rocket User Guide

DTIC Science & Technology

2007-08-01

26 8. ISTC Simulation Comparisons...Comparison c. Ground Range Comparison Figure 8. ISTC Simulation Comparisons Mini-Rocket User Guide REAL-WORLD COMPARISON 30 In particular, note...even though Mini-Rocket does not directly model the missile rigid body dynamics. The ISTC subsequently used Mini-Rocket as a driver to stimulate other

Evaluation of mini-implant sites in the posterior maxilla using traditional radiographs and cone-beam computed tomography

PubMed Central

Abbassy, Mona A.; Sabban, Hanady M.; Hassan, Ali H.; Zawawi, Khalid H.

2015-01-01

Objectives: To evaluate the accuracy of using routine 2-dimensional (2D) radiographs (panoramic and periapical) when evaluating the position of orthodontic temporary anchorage devices (mini-implants) in the maxilla, and to compare the results to 3-dimensional cone-beam computed tomography (CBCT). Methods: This cross-sectional study was conducted at King Abdulaziz University, Faculty of Dentistry, Jeddah, Kingdom of Saudi Arabia from February 2014 to January 2015. Panoramic and periapical radiographs were used to examine the position of mini-implants in relation to the adjacent roots. Rating of mini-implants position was performed by 82 dentists from different specialties, using 2 D images according to the following criteria: 1) away from the root; 2) mini-implant tip appears touching the lamina dura; and 3) mini-implant overlays the lamina dura. The results were compared with CBCT findings. Results: There was no difference between dentists from different specialties when rating the position of the mini-implants (Cronbach’s alpha=0.956). The accuracy of the periapical images was 45.1%, while the panoramic images 33.6%. However, both panoramic and periapical radiographs were significantly inaccurate when assessing the mini-implant position when compared with the CBCT findings (p=0.0001). Conclusion: Three-dimensional CBCT technology allows better visualization of mini-implant placement. The use of CBCT when assessing the position of mini-implants is recommended. PMID:26593168

Ceramic blade attachment system

DOEpatents

Boyd, G.L.

1995-04-11

A retainer ring is arranged to mount turbine blades to a turbine disk so that aerodynamic forces produced by a gas turbine engine are transferred from the turbine blades to the turbine disk to cause the turbine blades and turbine disk to rotate, but so that centrifugal forces of the turbine blades resulting from the rotation of the turbine blades and turbine disk are not transferred from the turbine blades to the turbine disk. 6 figures.

A DNA mini-barcode for land plants.

PubMed

Little, Damon P

2014-05-01

Small portions of the barcode region - mini-barcodes - may be used in place of full-length barcodes to overcome DNA degradation for samples with poor DNA preservation. 591,491,286 rbcL mini-barcode primer combinations were electronically evaluated for PCR universality, and two novel highly universal sets of priming sites were identified. Novel and published rbcL mini-barcode primers were evaluated for PCR amplification [determined with a validated electronic simulation (n = 2765) and empirically (n = 188)], Sanger sequence quality [determined empirically (n = 188)], and taxonomic discrimination [determined empirically (n = 30,472)]. PCR amplification for all mini-barcodes, as estimated by validated electronic simulation, was successful for 90.2-99.8% of species. Overall Sanger sequence quality for mini-barcodes was very low - the best mini-barcode tested produced sequences of adequate quality (B20 ≥ 0.5) for 74.5% of samples. The majority of mini-barcodes provide correct identifications of families in excess of 70.1% of the time. Discriminatory power noticeably decreased at lower taxonomic levels. At the species level, the discriminatory power of the best mini-barcode was less than 38.2%. For samples believed to contain DNA from only one species, an investigator should attempt to sequence, in decreasing order of utility and probability of success, mini-barcodes F (rbcL1/rbcLB), D (F52/R193) and K (F517/R604). For samples believed to contain DNA from more than one species, an investigator should amplify and sequence mini-barcode D (F52/R193). © 2013 John Wiley & Sons Ltd.

The use of cochlear's SCAN and wireless microphones to improve speech understanding in noise with the Nucleus6® CP900 processor.

PubMed

De Ceulaer, Geert; Pascoal, David; Vanpoucke, Filiep; Govaerts, Paul J

2017-11-01

The newest Nucleus CI processor, the CP900, has two new options to improve speech-in-noise perception: (1) use of an adaptive directional microphone (SCAN mode) and (2) wireless connection to MiniMic1 and MiniMic2 wireless remote microphones. An analysis was made of the absolute and relative benefits of these technologies in a real-world mimicking test situation. Speech perception was tested using an adaptive speech-in-noise test (sentences-in-babble noise). In session A, SRTs were measured in three conditions: (1) Clinical Map, (2) SCAN and (3) MiniMic1. Each was assessed for three distances between speakers and CI recipient: 1 m, 2 m and 3 m. In session B, the benefit of the use of MiniMic2 was compared to benefit of MiniMic1 at 3 m. A group of 13 adult CP900 recipients participated. SCAN and MiniMic1 improved performance compared to the standard microphone with a median improvement in SRT of 2.7-3.9 dB for SCAN at 1 m and 3 m, respectively, and 4.7-10.9 dB for the MiniMic1. MiniMic1 improvements were significant. MiniMic2 showed an improvement in SRT of 22.2 dB compared to 10.0 dB for MiniMic1 (3 m). Digital wireless transmission systems (i.e. MiniMic) offer a statistically and clinically significant improvement in speech perception in challenging, realistic listening conditions.

NREL: International Activities - Country Programs

Science.gov Websites

for use of mini-grid quality assurance and design standards and advising on mini-grid business models communities of practice and technical collaboration across countries on mini-grid development, modeling and interconnection standards and procedures, and with strengthening mini-grids and energy access programs. NREL is

Reading Mini-Lessons: An Instructional Practice for Meaning Centered Reading Programs.

ERIC Educational Resources Information Center

Barrentine, Shelby; And Others

1995-01-01

Mini-lessons (brief, informative explanations that demonstrate what readers do) are a key instructional practice in meaning centered reading programs. The content of the mini-lessons is determined by the needs of learners. In procedural mini-lessons, teachers explain the steps for successfully completing a task or performing a reading-related…

The Mini-Balance Evaluation Systems Test (Mini-BESTest) Demonstrates Higher Accuracy in Identifying Older Adult Participants With History of Falls Than Do the BESTest, Berg Balance Scale, or Timed Up and Go Test.

PubMed

Yingyongyudha, Anyamanee; Saengsirisuwan, Vitoon; Panichaporn, Wanvisa; Boonsinsukh, Rumpa

2016-01-01

Balance deficits a significant predictor of falls in older adults. The Balance Evaluation Systems Test (BESTest) and the Mini-Balance Evaluation Systems Test (Mini-BESTest) are tools that may predict the likelihood of a fall, but their capabilities and accuracies have not been adequately addressed. Therefore, this study aimed at examining the capabilities of the BESTest and Mini-BESTest for identifying older adult with history of falls and comparing the participants with history of falls identification accuracy of the BESTest, Mini-BESTest, Berg Balance Scale (BBS), and the Timed Up and Go Test (TUG) for identifying participants with a history of falls. Two hundred healthy older adults with a mean age of 70 years were classified into participants with and without history of fall groups on the basis of their 12-month fall history. Their balance abilities were assessed using the BESTest, Mini-BESTest, BBS, and TUG. An analysis of the resulting receiver operating characteristic curves was performed to calculate the area under the curve (AUC), sensitivity, specificity, cutoff score, and posttest accuracy of each. The Mini-BESTest showed the highest AUC (0.84) compared with the BESTest (0.74), BBS (0.69), and TUG (0.35), suggesting that the Mini-BESTest had the highest accuracy in identifying older adult with history of falls. At the cutoff score of 16 (out of 28), the Mini-BESTest demonstrated a posttest accuracy of 85% with a sensitivity of 85% and specificity of 75%. The Mini-BESTest had the highest posttest accuracy, with the others having results of 76% (BESTest), 60% (BBS), and 65% (TUG). The Mini-BESTest is the most accurate tool for identifying older adult with history of falls compared with the BESTest, BBS, and TUG.

Comparison between McMaster and Mini-FLOTAC methods for the enumeration of Eimeria maxima oocysts in poultry excreta.

PubMed

Bortoluzzi, C; Paras, K L; Applegate, T J; Verocai, G G

2018-04-30

Monitoring Eimeria shedding has become more important due to the recent restrictions to the use of antibiotics within the poultry industry. Therefore, there is a need for the implementation of more precise and accurate quantitative diagnostic techniques. The objective of this study was to compare the precision and accuracy between the Mini-FLOTAC and the McMaster techniques for quantitative diagnosis of Eimeria maxima oocyst in poultry. Twelve pools of excreta samples of broiler chickens experimentally infected with E. maxima were analyzed for the comparison between Mini-FLOTAC and McMaster technique using, the detection limits (dl) of 23 and 25, respectively. Additionally, six excreta samples were used to compare the precision of different dl (5, 10, 23, and 46) using the Mini-FLOTAC technique. For precision comparisons, five technical replicates of each sample (five replicate slides on one excreta slurry) were read for calculating the mean oocyst per gram of excreta (OPG) count, standard deviation (SD), coefficient of variation (CV), and precision of both aforementioned comparisons. To compare accuracy between the methods (McMaster, and Mini-FLOTAC dl 5 and 23), excreta from uninfected chickens was spiked with 100, 500, 1,000, 5,000, or 10,000 OPG; additional samples remained unspiked (negative control). For each spiking level, three samples were read in triplicate, totaling nine reads per spiking level per technique. Data were transformed using log10 to obtain normality and homogeneity of variances. A significant correlation (R = 0.74; p = 0.006) was observed between the mean OPG of the McMaster dl 25 and the Mini-FLOTAC dl 23. Mean OPG, CV, SD, and precision were not statistically different between the McMaster dl 25 and Mini-FLOTAC dl 23. Despite the absence of statistical difference (p > 0.05), Mini-FLOTAC dl 5 showed a numerically lower SD and CV than Mini-FLOTAC dl 23. The Pearson correlation coefficient revealed significant and positive correlation among the four dl (p ≤ 0.05). In the accuracy study, it was observed that the Mini-FLOTAC dl 5 and 23 were more accurate than the McMaster for 100 OPG, and the Mini-FLOTAC dl 23 had the highest accuracy for 500 OPG. The McMaster and Mini-FLOTAC dl 23 techniques were more accurate than the Mini-FLOTAC dl 5 for 5,000 OPG, and both dl of the Mini-FLOTAC were less accurate for 10,000 OPG counts than the McMaster technique. However, the overall accuracy of the Mini-FLOTAC dl 23 was higher than the McMaster and Mini-FLOTAC dl 5 techniques. Copyright © 2018 Elsevier B.V. All rights reserved.

Teacher Supervision and Evaluation: A Case Study of Administrators' and Teachers' Perceptions of Mini Observations

ERIC Educational Resources Information Center

Campbell, Thomas F.

2013-01-01

This case study will investigate teachers' and administrators' perceptions of the relationship between mini observations and teacher performance to understand what effect, if any, a system of mini observations has on teacher performance, and if mini observations influences a teacher's pedagogical practice differently than a…

Effects of monocortical and bicortical mini-implant anchorage on bone-borne palatal expansion using finite element analysis.

PubMed

Lee, Robert J; Moon, Won; Hong, Christine

2017-05-01

Bone-borne palatal expansion relies on mini-implant stability for successful orthopedic expansion. The large magnitude of applied force experienced by mini-implants during bone-borne expansion may lead to high failure rates. Use of bicortical mini-implant anchorage rather than monocortical anchorage may improve mini-implant stability. The aims of this study were to analyze and compare the effects of bicortical and monocortical anchorages on stress distribution and displacement during bone-borne palatal expansion using finite element analysis. Two skull models were constructed to represent expansion before and after midpalatal suture opening. Three clinical situations with varying mini-implant insertion depths were studied in each skull model: monocortical, 1-mm bicortical, and 2.5-mm bicortical. Finite element analysis simulations were performed for each clinical situation in both skull models. Von Mises stress distribution and transverse displacement were evaluated for all models. Peri-implant stress was greater in the monocortical anchorage model compared with both bicortical anchorage models. In addition, transverse displacement was greater and more parallel in the coronal plane for both bicortical models compared with the monocortical model. Minimal differences were observed between the 1-mm and the 2.5-mm bicortical models for both peri-implant stress and transverse displacement. Bicortical mini-implant anchorage results in improved mini-implant stability, decreased mini-implant deformation and fracture, more parallel expansion in the coronal plane, and increased expansion during bone-borne palatal expansion. However, the depth of bicortical mini-implant anchorage was not significant. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Effects of monocortical and bicortical mini-implant anchorage on bone-borne palatal expansion using finite element analysis

PubMed Central

Lee, Robert J.; Moon, Won; Hong, Christine

2017-01-01

Introduction Bone-borne palatal expansion relies on mini-implant stability for successful orthopedic expansion. The large magnitude of applied force experienced by mini-implants during bone-borne expansion may lead to high failure rates. Use of bicortical mini-implant anchorage rather than monocortical anchorage may improve mini-implant stability. The aim of this study was to analyze and compare the effects of bicortical and monocortical anchorage on stress distribution and displacement during bone-borne palatal expansion using finite element analysis (FEA). Methods Two skull models were constructed to represent expansion prior to and after midpalatal suture opening. Three clinical situations with varying mini-implant insertion depths were studied in each skull model: monocortical, 1mm bicortical, and 2.5mm bicortical. FEA simulations were performed for each clinical situation in both skull models. Von Mises stress distribution and transverse displacement was evaluated for all models. Results Peri-implant stress was greater in the monocortical anchorage model compared to both bicortical anchorage models. In addition, transverse displacement was greater and more parallel in the coronal plane for both bicortical models compared to the monocortical model. Minimal differences were observed between the 1mm bicortical and 2.5mm bicortical models for both peri-implant stress and transverse displacement. Conclusions Bicortical mini-implant anchorage results in improved mini-implant stability, decreased mini-implant deformation and fracture, more parallel expansion in the coronal plane, and increased expansion during bone-borne palatal expansion. However, the depth of bicortical mini-implant anchorage was not significant. PMID:28457266

Cogeneration steam turbines from Siemens: New solutions

NASA Astrophysics Data System (ADS)

Kasilov, V. F.; Kholodkov, S. V.

2017-03-01

The Enhanced Platform system intended for the design and manufacture of Siemens AG turbines is presented. It combines organizational and production measures allowing the production of various types of steam-turbine units with a power of up to 250 MWel from standard components. The Enhanced Platform designs feature higher efficiency, improved reliability, better flexibility, longer overhaul intervals, and lower production costs. The design features of SST-700 and SST-900 steam turbines are outlined. The SST-700 turbine is used in backpressure steam-turbine units (STU) or as a high-pressure cylinder in a two-cylinder condensing turbine with steam reheat. The design of an SST-700 single-cylinder turbine with a casing without horizontal split featuring better flexibility of the turbine unit is presented. An SST-900 turbine can be used as a combined IP and LP cylinder (IPLPC) in steam-turbine or combined-cycle power units with steam reheat. The arrangements of a turbine unit based on a combination of SST-700 and SST-900 turbines or SST-500 and SST-800 turbines are presented. Examples of this combination include, respectively, PGU-410 combinedcycle units (CCU) with a condensing turbine and PGU-420 CCUs with a cogeneration turbine. The main equipment items of a PGU-410 CCU comprise an SGT5-4000F gas-turbine unit (GTU) and STU consisting of SST-700 and SST-900RH steam turbines. The steam-turbine section of a PGU-420 cogeneration power unit has a single-shaft turbine unit with two SST-800 turbines and one SST-500 turbine giving a power output of N el. STU = 150 MW under condensing conditions.

Mini-tablets versus pellets as promising multiparticulate modified release delivery systems for highly soluble drugs.

PubMed

Gaber, Dina M; Nafee, Noha; Abdallah, Osama Y

2015-07-05

Whether mini-tablets (tablets, diameters ≤6mm) belong to single- or multiple-unit dosage forms is still questionable. Accordingly, Pharmacopoeial evaluation procedures for mini-tablets are lacking. In this study, the aforementioned points were discussed. Moreover, their potential for oral controlled delivery was assessed. The antidepressant venlafaxine hydrochloride (Vx), a highly soluble drug undergoing first pass effect, low bioavailability and short half-life was selected as a challenging payload. In an attempt to weigh up mini-tablets versus pellets as multiparticulate carriers, Vx-loaded mini-tablets were compared to formulated pellets of the same composition and the innovator Effexor(®)XR pellets. Formulations were prepared using various polymer hydrogels in the core and ethyl cellulose film coating with increasing thickness. Mini-tablets (diameter 2mm) showed extended Vx release (<60%, 8h). Indeed, release profiles comparable to Effexor(®)XR pellets were obtained. Remarkably higher coating thickness was required for pellets to provide equivalent retardation. Ethyl cellulose in the core ensured faster release due to polymer migration to the surface and pore formation in the coat. mini-tablets showed higher stability to pellets upon storage. Industrially speaking, mini-tablets proved to be superior to pellets in terms of manufacturing, product quality and economical aspects. Results point out the urgent need for standardized evaluation procedures for mini-tablets. Copyright © 2015. Published by Elsevier B.V.

The development and evaluation of mini-GEMs - short, focused, online e-learning videos in geriatric medicine.

PubMed

Garside, Mark J; Fisher, James M; Blundell, Adrian G; Gordon, Adam L

2018-01-01

Mini Geriatric E-Learning Modules (Mini-GEMs) are short, focused, e-learning videos on geriatric medicine topics, hosted on YouTube, which are targeted at junior doctors working with older people. This study aimed to explore how these resources are accessed and used. The authors analyzed the viewing data from 22 videos published over the first 18 months of the Mini-GEM project. We conducted a focus group of U.K. junior doctors considering their experiences with Mini-GEMS. The Mini-GEMs were viewed 10,291 times over 18 months, equating to 38,435 minutes of total viewing time. The average viewing time for each video was 3.85 minutes. Learners valued the brevity and focused nature of the Mini-GEMs and reported that they watched them in a variety of settings to supplement clinical experiences and consolidate learning. Watching the videos led to an increase in self-reported confidence in managing older patients. Mini-GEMs can effectively disseminate clinical teaching material to a wide audience. The videos are valued by junior doctors due to their accessibility and ease of use.

Impact of implant design on primary stability of orthodontic mini-implants.

PubMed

Wilmes, Benedict; Ottenstreuer, Stephanie; Su, Yu-Yu; Drescher, Dieter

2008-01-01

Skeletal anchorage with mini-implants has greatly broadened the treatment possibilities in orthodontics over the last few years. To reduce implant failure rates, it is advisable to obtain adequate primary stability. The aim of this study was to quantitatively analyze the impact of implant design and dimension on primary stability. Forty-two porcine iliac bone segments were prepared and embedded in resin. To evaluate the primary stability, we documented insertion torques of the following mini-implants: Aarhus Screw, AbsoAnchor, LOMAS, Micro-Anchorage-System, ORLUS and Spider Screw. In each bone, five Dual Top Screws were inserted for reference purposes to achieve comparability among the specimens. We observed wide variation in insertion torques and hence primary stability, depending on mini-implant design and dimension; the great impact that mini-implant diameter has on insertion torques was particularly conspicuous. Conical mini-implants achieved higher primary stabilities than cylindrical designs. The diameter and design of the mini-implant thread have a distinctive impact on primary stability. Depending on the region of insertion and local bone quality, the choice of the mini-implant design and size is crucial to establish sufficient primary stability.

Turbine design review text

NASA Technical Reports Server (NTRS)

1975-01-01

Three-volume publication covers theoretical, design, and performance aspects of turbines. Volumes cover thermodynamic and fluid-dynamic concepts, velocity diagram design, turbine blade aerodynamic design, turbine energy losses, supersonic turbines, radial-inflow turbines, turbine cooling, and aerodynamic performance testing.

Turbine blade tip gap reduction system

DOEpatents

Diakunchak, Ihor S.

2012-09-11

A turbine blade sealing system for reducing a gap between a tip of a turbine blade and a stationary shroud of a turbine engine. The sealing system includes a plurality of flexible seal strips extending from a pressure side of a turbine blade generally orthogonal to the turbine blade. During operation of the turbine engine, the flexible seal strips flex radially outward extending towards the stationary shroud of the turbine engine, thereby reducing the leakage of air past the turbine blades and increasing the efficiency of the turbine engine.

Nonlinear Modeling of Joint Dominated Structures

NASA Technical Reports Server (NTRS)

Chapman, J. M.

1990-01-01

The development and verification of an accurate structural model of the nonlinear joint-dominated NASA Langley Mini-Mast truss are described. The approach is to characterize the structural behavior of the Mini-Mast joints and struts using a test configuration that can directly measure the struts' overall stiffness and damping properties, incorporate this data into the structural model using the residual force technique, and then compare the predicted response with empirical data taken by NASA/LaRC during the modal survey tests of the Mini-Mast. A new testing technique, referred to as 'link' testing, was developed and used to test prototype struts of the Mini-Masts. Appreciable nonlinearities including the free-play and hysteresis were demonstrated. Since static and dynamic tests performed on the Mini-Mast also exhibited behavior consistent with joints having free-play and hysteresis, nonlinear models of the Mini-Mast were constructed and analyzed. The Residual Force Technique was used to analyze the nonlinear model of the Mini-Mast having joint free-play and hysteresis.

[Bone remodeling and modeling/mini-modeling.

PubMed

Hasegawa, Tomoka; Amizuka, Norio

Modeling, adapting structures to loading by changing bone size and shapes, often takes place in bone of the fetal and developmental stages, while bone remodeling-replacement of old bone into new bone-is predominant in the adult stage. Modeling can be divided into macro-modeling(macroscopic modeling)and mini-modeling(microscopic modeling). In the cellular process of mini-modeling, unlike bone remodeling, bone lining cells, i.e., resting flattened osteoblasts covering bone surfaces will become active form of osteoblasts, and then, deposit new bone onto the old bone without mediating osteoclastic bone resorption. Among the drugs for osteoporotic treatment, eldecalcitol(a vitamin D3 analog)and teriparatide(human PTH[1-34])could show mini-modeling based bone formation. Histologically, mature, active form of osteoblasts are localized on the new bone induced by mini-modeling, however, only a few cell layer of preosteoblasts are formed over the newly-formed bone, and accordingly, few osteoclasts are present in the region of mini-modeling. In this review, histological characteristics of bone remodeling and modeling including mini-modeling will be introduced.

Comparison Between Transverse Mini-Incision and Longitudinal Mini-Incision for the Resection of Locally Advanced Colonic Cancer

PubMed Central

Ishida, Hideyuki; Sobajima, Jun; Yokoyama, Masaru; Nakada, Hiroshi; Okada, Norimichi; Kumamoto, Kensuke; Ishibashi, Keiichiro

2014-01-01

We performed a retrospective review of non-overweight (body mass index ≤ 25 kg/m2) patients scheduled to undergo a curative resection of locally advanced colon cancer via a transverse mini-incision (n = 62) or a longitudinal mini-incision (skin incision ≤7 cm, n = 62), with the latter group of patients randomly selected as historical controls matched with the former group according to tumor location. Extension of the transverse mini-incision wound was necessary in 3 patients (5%). Both groups were largely equivalent in terms of demographic, clinicopathological, and surgical factors and frequency of postoperative complications. Postoperative analgesic was significantly less (P = 0.04) and postoperative length of the hospital stay was significantly shorter (P < 0.01) in the transverse mini-incision group. Concerning a mini-incision approach for locally advanced colonic cancer, a transverse incision seems to be advantageous with regard to minimal invasiveness and early recovery compared with a longitudinal incision. PMID:24833142

Mini-marathon groups: psychological "first aid" following disasters.

PubMed

Terr, L C

1992-01-01

Large group counseling sessions for soldiers following battle have been commonly used since World War II. The author conceptualizes and demonstrates how these mini-marathon sessions can be adapted to support all ages and types of civilians involved in disasters. Mini-marathons take about 3 hours and are divided into three sections: story sharing, symptom sharing, and suggestions for self-help, including sharing tales of heroism and survival. After an initial mini-marathon session, a second session may be held emphasizing creativity. The author also describes how mini-marathons can be adapted for therapists who will lead their own sessions.

Numerical analysis of flow interaction of turbine system in two-stage turbocharger of internal combustion engine

NASA Astrophysics Data System (ADS)

Liu, Y. B.; Zhuge, W. L.; Zhang, Y. J.; Zhang, S. Y.

2016-05-01

To reach the goal of energy conservation and emission reduction, high intake pressure is needed to meet the demand of high power density and high EGR rate for internal combustion engine. Present power density of diesel engine has reached 90KW/L and intake pressure ratio needed is over 5. Two-stage turbocharging system is an effective way to realize high compression ratio. Because turbocharging system compression work derives from exhaust gas energy. Efficiency of exhaust gas energy influenced by design and matching of turbine system is important to performance of high supercharging engine. Conventional turbine system is assembled by single-stage turbocharger turbines and turbine matching is based on turbine MAP measured on test rig. Flow between turbine system is assumed uniform and value of outlet physical quantities of turbine are regarded as the same as ambient value. However, there are three-dimension flow field distortion and outlet physical quantities value change which will influence performance of turbine system as were demonstrated by some studies. For engine equipped with two-stage turbocharging system, optimization of turbine system design will increase efficiency of exhaust gas energy and thereby increase engine power density. However flow interaction of turbine system will change flow in turbine and influence turbine performance. To recognize the interaction characteristics between high pressure turbine and low pressure turbine, flow in turbine system is modeled and simulated numerically. The calculation results suggested that static pressure field at inlet to low pressure turbine increases back pressure of high pressure turbine, however efficiency of high pressure turbine changes little; distorted velocity field at outlet to high pressure turbine results in swirl at inlet to low pressure turbine. Clockwise swirl results in large negative angle of attack at inlet to rotor which causes flow loss in turbine impeller passages and decreases turbine efficiency. However negative angle of attack decreases when inlet swirl is anti-clockwise and efficiency of low pressure turbine can be increased by 3% compared to inlet condition of clockwise swirl. Consequently flow simulation and analysis are able to aid in figuring out interaction mechanism of turbine system and optimizing turbine system design.

Gas Turbine Engine Having Fan Rotor Driven by Turbine Exhaust and with a Bypass

NASA Technical Reports Server (NTRS)

Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

2016-01-01

A gas turbine engine has a core engine incorporating a core engine turbine. A fan rotor is driven by a fan rotor turbine. The fan rotor turbine is in the path of gases downstream from the core engine turbine. A bypass door is moveable from a closed position at which the gases from the core engine turbine pass over the fan rotor turbine, and moveable to a bypass position at which the gases are directed away from the fan rotor turbine. An aircraft is also disclosed.

Diagnostic validity Polish language version of the questionnaire MINI-KID (Mini International Neuropsychiatry Interview for Children and Adolescent).

PubMed

Adamowska, Sylwia; Sylwia, Adamowska; Adamowski, Tomasz; Tomasz, Adamowski; Frydecka, Dorota; Dorota, Frydecka; Kiejna, Andrzej; Andrzej, Kiejna

2014-10-01

Since over forty years structuralized interviews for clinical and epidemiological research in child and adolescent psychiatry are being developed that should increase validity and reliability of diagnoses according to classification systems (DSM and ICD). The aim of the study is to assess the validity of the Polish version of MINI-KID (Mini International Neuropsychiatric Interview for Children and Adolescents) in comparison to clinical diagnosis made by a specialist in the field of child and adolescent psychiatry. There were 140 patients included in the study (93 boys, 66.4%, mean age 11.8±3.0 and 47 girls 33.5%, mean age 14.0±2.9). All the patients were diagnosed by the specialist in the field of child and adolescent psychiatry according to ICD-10 criteria and by the independent interviewer with the Polish version of MINI-KID (version 2.0, 2001). There was higher agreement between clinical diagnoses and diagnoses based on MINI-KID interview with respect to eating disorders and externalizing disorders (κ 0.43-0.56) and lower in internalizing disorders (κ 0.13-0.45). In the clinical interview, there was smaller number of diagnostic categories (maximum 3 diagnoses per one patient) in comparison to MINI-KID (maximum 10 diagnoses per one patient), and the smaller percentage of patients with one diagnosis (65,7%) in comparison to MINI-KID interview (72%). Our study has shown satisfactory validity parameters of MINI-KID questionnaire, promoting its use for clinical and epidemiological settings. The Mini International Neuropsychiatry Interview for Children and Adolescent (MINI-KID) is the first structuralized diagnostic interview for assessing mental status in children and adolescents, which has been translated into Polish language. Our validation study demonstrated satisfactory psychometric properties of the questionnaire, enabling its use in clinical practice and in research projects. Copyright © 2014 Elsevier Inc. All rights reserved.

Satisfaction, function and repair integrity after arthroscopic versus mini-open rotator cuff repair.

PubMed

Barnes, L A Fink; Kim, H M; Caldwell, J-M; Buza, J; Ahmad, C S; Bigliani, L U; Levine, W N

2017-02-01

Advances in arthroscopic techniques for rotator cuff repair have made the mini-open approach less popular. However, the mini-open approach remains an important technique for repair for many surgeons. The aims of this study were to compare the integrity of the repair, the function of the shoulder and satisfaction post-operatively using these two techniques in patients aged > 50 years. We identified 22 patients treated with mini-open and 128 patients treated with arthroscopic rotator cuff repair of July 2007 and June 2011. The mean follow-up was two years (1 to 5). Outcome was assessed using the American Shoulder and Elbow Surgeons (ASES) and Simple Shoulder Test (SST) scores, and satisfaction. The integrity of the repair was assessed using ultrasonography. A power analysis ensured sufficient enrolment. There was no statistically significant difference between the age, function, satisfaction, or pain scores (p > 0.05) of the two groups. The integrity of the repair and the mean SST scores were significantly better in the mini-open group (91% of mini-open repairs were intact versus 60% of arthroscopic repairs, p = 0.023; mean SST score 10.9 (standard deviation (sd) 1.3) in the mini-open group; 8.9 (sd 3.5) in arthroscopic group; p = 0.003). The ASES scores were also higher in the mini-open group (mean ASES score 91.0 (sd 10.5) in mini-open group; mean 82.70 (sd 19.8) in the arthroscopic group; p = 0.048). The integrity of the repair and function of the shoulder were better after a mini-open repair than after arthroscopic repair of a rotator cuff tear in these patients. The functional difference did not translate into a difference in satisfaction. Mini-open rotator cuff repair remains a useful technique despite advances in arthroscopy. Cite this article: Bone Joint J 2017;99-B:245-9. ©2017 The British Editorial Society of Bone & Joint Surgery.

Comparison of the Mini-Balance Evaluations Systems Test with the Berg Balance Scale in relationship to walking speed and motor recovery post stroke.

PubMed

Madhavan, Sangeetha; Bishnoi, Alka

2017-12-01

The Mini-BESTest is a recently developed balance assessment tool that incorporates challenging dynamic balance tasks. Few studies have compared the psychometric properties of the Mini-BESTest to the commonly used Berg Balance Scale (BBS). However, the utility of these scales in relationship to post stroke walking speeds has not been explored. The purpose of this study was to compare the sensitivity and specificity of the Mini-BESTest and BBS to evaluate walking speeds in individuals with stroke. A retrospective exploratory design. Forty-one individuals with chronic stroke were evaluated with the Mini-BESTest, BBS, and 10-meter self-selected walk test (10MWT). Based on their self-selected gait speeds (below or above 0.8 m/s), participants were classified as slow and fast walkers. Significant linear correlations were observed between the Mini-BESTest vs. BBS (r = 0.72, p ≤ 0.001), Mini-BESTest vs. 10MWT (r = 0.58, p ≤ 0.001), and BBS vs. 10MWT (r = 0.30, p = 0.05). Independent t-tests comparing the balance scores for the slow and fast walkers revealed significant group differences for the Mini-BESTest (p = 0.003), but not for the BBS (p = 0.09). The Mini-BESTest demonstrated higher sensitivity (93%) and specificity (64%) compared to the BBS (sensitivity 81%, specificity 56%) for discriminating participants into slow and fast walkers. The Mini-BESTest has a greater discriminative ability than the BBS to categorize individuals with stroke into slow and fast walkers.

Comparison of the Mini-Balance Evaluations Systems Test with the Berg Balance Scale in relationship to walking speed and motor recovery post stroke

PubMed Central

Madhavan, Sangeetha; Bishnoi, Alka

2017-01-01

Background The Mini-BESTest is a recently developed balance assessment tool that incorporates challenging dynamic balance tasks. Few studies have compared the psychometric properties of the Mini-BESTest to the commonly used Berg Balance Scale (BBS). However, the utility of these scales in relationship to post stroke walking speeds has not been explored. Objectives The purpose of this study was to compare the sensitivity and specificity of the Mini-BESTest and BBS to evaluate walking speeds in individuals with stroke. Design A retrospective exploratory design. Methods Forty-one individuals with chronic stroke were evaluated with the Mini-BESTest, BBS, and 10-meter self-selected walk test (10MWT). Based on their self-selected gait speeds (below or above 0.8 m/s), participants were classified as slow and fast walkers. Results Significant linear correlations were observed between the Mini-BESTest vs. BBS (r = 0.72, p ≤ 0.001), Mini-BESTest vs. 10MWT (r = 0.58, p ≤ 0.001), and BBS vs. 10MWT (r = 0.30, p = 0.05). Independent t-tests comparing the balance scores for the slow and fast walkers revealed significant group differences for the Mini-BESTest (p =0.003), but not for the BBS (p = 0.09). The Mini-BESTest demonstrated higher sensitivity (93%) and specificity (64%) compared to the BBS (sensitivity 81%, specificity 56%) for discriminating participants into slow and fast walkers. No significant results were observed with the FMLE-M scores. Conclusions The Mini-BESTest has a greater discriminative ability than the BBS to categorize individuals with stroke into slow and fast walkers. PMID:28826325

The Mini-Social Phobia Inventory: psychometric properties in an adolescent general population sample.

PubMed

Ranta, Klaus; Kaltiala-Heino, Riittakerttu; Rantanen, Päivi; Marttunen, Mauri

2012-07-01

Onset of social phobia (SP) typically occurs in adolescence. Short screening instruments for its assessment are needed for use in primary health and school settings. The 3-item Mini-Social Phobia Inventory (SPIN) has demonstrated effectiveness in screening for generalized SP (GSP) in adults. This study examined the psychometrics of the Mini-SPIN in an adolescent general population sample. Three hundred fifty adolescents aged 12 to 17 years were clinically interviewed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version for identification of SP and other Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Axis I disorders, blind to their Mini-SPIN status. Associations between SP; subclinical SP; other anxiety, depressive, and disruptive disorders; and Mini-SPIN scores were examined, and diagnostic efficiency statistics were calculated. The association between Mini-SPIN scores and the generalized subtype of SP was also examined. As in adults, the Mini-SPIN items differentiated subjects with SP from those without. A score of 6 points or greater was found optimal in predicting SP with a sensitivity of 86%, specificity of 84%, and positive and negative predictive values of 26% and 99%. The Mini-SPIN also possessed discriminative validity, as scores were higher for adolescents with SP than they were for those with depressive, disruptive, and other anxiety disorders. The Mini-SPIN was also able to differentiate adolescents with GSP from the rest of the sample. The Mini-SPIN has good psychometrics for screening SP in adolescents from general population and may have value in screening for GSP. Copyright © 2012 Elsevier Inc. All rights reserved.

Comparison of flexible ureterorenoscopy and mini-percutaneous nephrolithotomy in treatment of lower calyceal stones smaller than 2 cm.

PubMed

Akbulut, Fatih; Kucuktopcu, Onur; Kandemir, Emre; Sonmezay, Erkan; Simsek, Abdulmuttalip; Ozgor, Faruk; Binbay, Murat; Muslumanoglu, Ahmet Yaser; Gurbuz, Gokhan

2016-01-01

To compare the outcomes of flexible ureterorenoscopy (F-URS) and mini-percutaneous nephrolithotomy (mini-PNL) in the treatment of lower calyceal stones smaller than 2 cm. Patients who underwent F-URS and mini-PNL for the treatment of lower calyceal stones smaller than 2 cm between March 2009 and December 2014 were retrospectively evaluated. Ninety-four patients were divided into two groups by treatment modality: F-URS (Group 1: 63 patients) and mini-PNL (Group 2: 31 patients). All patients were preoperatively diagnosed with intravenous pyelography or computed tomography. Success rates for F-URS and mini-PNL at postoperative first month were 85.7% and 90.3%, respectively. Operation time, fluoroscopy time, and hospitalization time for F-URS and mini-PNL patients were 44.40 min, 2.9 min, 22.4 h, and 91.9 min, 6.4 min, and 63.8 h, respectively. All three parameters were significantly shorter among the F-URS group (p < 0.001). Postoperative hemoglobin drop was significantly lower in F-URS group compared to mini-PNL group (0.39 mg/dL vs. 1.15 mg/dL, p = 0.001). A comparison of complications according to the Clavien classification demonstrated significant differences between the groups (p = 0.001). More patients in the F-URS groups require antibiotics due to urinary tract infection, and more patients in the mini-PNL group required ureteral double J catheter insertion under general anesthesia. Although both F-URS and mini-PNL have similar success rates for the treatment of lower calyceal stones, F-URS appears to be more favorable due to shorter fluoroscopy and hospitalization times; and lower hemoglobin drops. Multicenter and studies using higher patient volumes are needed to confirm these findings.

Maxillary anterior en masse retraction using different antero-posterior position of mini screw: a 3D finite element study.

PubMed

Hedayati, Zohreh; Shomali, Mehrdad

2016-12-01

Nowadays, mini screws are used in orthodontic tooth movement to obtain maximum or absolute anchorage. They have gained popularity among orthodontists for en masse retraction of anterior teeth after first premolar extraction in maximum anchorage cases. The purpose of this study was to determine the type of anterior tooth movement during the time when force was applied from different mini screw placements to the anterior power arm with various heights. A finite element method was used for modeling maxillary teeth and bone structure. Brackets, wire, and hooks were also designed for modeling. Two appropriate positions for mini screw in the mesial and distal of the second premolar were designed as fixed nodes. Forces were applied from the mini screw to four different levels of anterior hook height: 0, 3, 6, and 9 mm. Initial tooth movement in eight different conditions was analyzed and calculated with ANSYS software. Rotation of anterior dentition was decreased with a longer anterior power arm and the mesial placement of the mini screw. Bodily movements occurred with the 9-mm height of the power arm in both mini screw positions. Intrusion or extrusion of the anterior teeth segment depended on the level of the mini screw and the edge of the power arm on the Z axis. According to the findings of this study, the best control in the sagittal plane during anterior en masse retraction was achieved by mesial placement of the mini screw and the 9-mm height of the anterior power arm. Where control in the vertical plane was concerned, distal placement of the mini screw with the 6-mm power arm height had minimum adverse effect on anterior dentition.

Cooled snubber structure for turbine blades

DOEpatents

Mayer, Clinton A.; Campbell, Christian X.; Whalley, Andrew; Marra, John J.

2014-04-01

A turbine blade assembly in a turbine engine. The turbine blade assembly includes a turbine blade and a first snubber structure. The turbine blade includes an internal cooling passage containing cooling air. The first snubber structure extends outwardly from a sidewall of the turbine blade and includes a hollow interior portion that receives cooling air from the internal cooling passage of the turbine blade.

Performance of J33 turbojet engine with shaft-power extraction III : turbine performance

NASA Technical Reports Server (NTRS)

Huppert, M C; Nettles, J C

1949-01-01

The performance of the turbine component of a J33 turbojet engine was determined over a range of turbine speeds from 8000 to 11,500 rpm.Turbine-inlet temperature was varied from the minimum required to drive the compressor to a maximum of approximately 2000 degrees R at each of several intermediate turbine speeds. Data are presented that show the horsepower developed by the turbine per pound of gas flow. The relation between turbine-inlet stagnation pressure, turbine-outlet stagnation pressure, and turbine-outlet static pressure was established. The turbine-weight-flow parameter varied from 39.2 to 43.6. The maximum turbine efficiency measured was 0.86 at a pressure ratio of 3.5 and a ratio of blade speed to theoretical nozzle velocity of 0.39. A generalized performance map of the turbine-horsepower parameter plotted against the turbine-speed parameter indicated that the best turbine efficiency is obtained when the turbine power is 10 percent greater than the compressor horsepower. The variation of efficiency with the ratio of blade speed to nozzle velocity indicated that the turbine operates at a speed above that for maximum efficiency when the engine is operated normally with the 19-inch-diameter jet nozzle.

Review of Strategies and Technologies for Demand-Side Management on Isolated Mini-Grids

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

Harper, Meg

This review provides an overview of strategies and currently available technologies used for demandside management (DSM) on mini-grids throughout the world. For the purposes of this review, mini-grids are defined as village-scale electricity distribution systems powered by small local generation sources and not connected to a main grid.1 Mini-grids range in size from less than 1 kW to several hundred kW of installed generation capacity and may utilize different generation technologies, such as micro-hydro, biomass gasification, solar, wind, diesel generators, or a hybrid combination of any of these. This review will primarily refer to AC mini-grids, though much of themore » discussion could apply to DC grids as well. Many mini-grids include energy storage, though some rely solely on real-time generation.« less

Boosting devices with integral features for recirculating exhaust gas

DOEpatents

Wu, Ko-Jen

2015-12-22

According to one embodiment of the invention, a turbine housing includes a turbine inlet in fluid communication with a turbine volute configured to house a turbine wheel, the turbine inlet configured to direct an exhaust gas flow from an engine to the turbine wheel. The turbine housing also includes a turbine outlet in fluid communication with the turbine volute, the turbine outlet configured to direct the exhaust gas flow to an exhaust gas conduit and a first exhaust gas recirculation supply port located on and in fluid communication with the turbine outlet, the first exhaust gas recirculation supply port being configured to direct a portion of the exhaust gas flow to an exhaust gas recirculation supply conduit.

Axial pico turbine - construction and experimental research

NASA Astrophysics Data System (ADS)

Peczkis, G.; Goryca, Z.; Korczak, A.

2017-08-01

The paper concerns axial water turbine of power equal to 1 kW. The example of axial water turbine constructional calculations was provided, as well as turbine rotor construction with NACA profile blades. The laboratory test rig designed and built to perform measurements on pico turbine was described. The turbine drove three-phase electrical generator. On the basis of highest efficiency parameters, pico turbine basic characteristics were elaborated. The experimental research results indicated that pico turbine can achieve maximum efficiency close to the values of larger water turbines.

[Validation of the portuguese version of the Mini-Social Phobia Inventory (Mini-SPIN)].

PubMed

D'El Rey, Gustavo José Fonseca; Matos, Cláudia Wilmor

2009-01-01

Social phobia (also known as social anxiety disorder) is a severe mental disorder that brings distress and disability. The aim of this study was validate to the Portuguese language the Mini-Social Phobia Inventory (Mini-SPIN) in a populational sample. We performed a discriminative validity study of the Mini-SPIN in a sample of 644 subjects (Mini-SPIN positive group: n = 218 and control/negative group: n = 426) of a study of anxiety disorders' prevalence in the city of Santo André-SP. The Portuguese version of the Mini-SPIN (with score of 6 points, suggested in the original English version) demonstrated a sensitivity of 95.0%, specificity of 80.3%, positive predictive value of 52.8%, negative predictive value of 98.6% and incorrect classification rate of 16.9%. With score of 7 points, was observed an increase in the specificity and positive predictive value (88.6% and 62.7%), while the sensitivity and negative predictive value (84.8% and 96.2%) remained high. The Portuguese version of the Mini-SPIN showed satisfactory psychometric qualities in terms of discriminative validity. In this study, the cut-off of 7, was considered to be the most suitable to screening of the generalized social phobia.

A simple three-dimensional stent for proper placement of mini-implant

PubMed Central

2013-01-01

Background This paper deals with the fabrication of a three-dimensional stent which is simple in design but provides an accurate placement of a mini-implant in three planes of space, namely, sagittal (root proximity), vertical (attached gingiva/alveolar mucosa) and transverse (angulation). Findings The stent is made of 0.018 × 0.025 in. stainless steel archwire which consists of a ‘u loop’ angulated at 20°, a vertical limb, a horizontal limb and a stop. The angulation of the ‘u’ helps in the placement of the mini-implant at 70° to the long axis of the tooth. The vertical height is determined such that the mini-implant is placed at the mucogingival junction. The mini-implant is placed with the aid of the stent, and its angulation and proximity to the adjacent roots are checked with a cone beam computed tomography image. The cone beam computed tomography image showed the mini-implant at an angle of 70° to the long axis of the tooth. There is no contact between mini-implant and the roots of the adjacent teeth. Conclusion This stent is simple, easy to fabricate, cost-effective, and provides ease of insertion/removal, and three-dimensional orientation of the mini-implant. PMID:24326158

Cooling of Gas Turbines. 6 - Computed Temperature Distribution through Cross Section of Water-Cooled Turbine Blade

DTIC Science & Technology

1947-05-01

AERONAUTICS Figure 7. - Cross section of water-cooleä turbine blade showing location and size of seven coolant...Power Plants.~ Jet and~ Turbine ($) [SECTION. Turbines (I3) [CROSS DEFERENCES. Turbine blades - Thermal measurements (95350); Turbine blades ...section of water-cooled turbine blade FORG’N. TITLE: v.. ’V, ORIGINATING AGENCY. TRANSLATION. National Advisory Committee for Aeronautics

First Atmospheric Science Results from the Mars Exploration Rovers Mini-TES

NASA Technical Reports Server (NTRS)

Smith, Michael D.; Wolff, Michael J.; Lemmon, Mark T.; Spanovich, Nicole; Banfield, Don; Budney, Charles J.; Clancy, R. Todd; Ghosh, Amitabha; Landis, Geoffrey A.; Smith, Peter;

First Atmospheric Science Results from the Mars Exploration Rovers Mini-TES.

PubMed

Smith, Michael D; Wolff, Michael J; Lemmon, Mark T; Spanovich, Nicole; Banfield, Don; Budney, Charles J; Clancy, R Todd; Ghosh, Amitabha; Landis, Geoffrey A; Smith, Peter; Whitney, Barbara; Christensen, Philip R; Squyres, Steven W

2004-12-03

Thermal infrared spectra of the martian atmosphere taken by the Miniature Thermal Emission Spectrometer (Mini-TES) were used to determine the atmospheric temperatures in the planetary boundary layer and the column-integrated optical depth of aerosols. Mini-TES observations show the diurnal variation of the martian boundary layer thermal structure, including a near-surface superadiabatic layer during the afternoon and an inversion layer at night. Upward-looking Mini-TES observations show warm and cool parcels of air moving through the Mini-TES field of view on a time scale of 30 seconds. The retrieved dust optical depth shows a downward trend at both sites.

Arc-to-Arc mini-sling 1999: a critical analysis of concept and technology.

PubMed

Palma, Paulo

2011-01-01

The aim of this study was to critically review the Arc-to-Arc mini-sling (Palma's technique) a less invasive mid-urethral sling using bovine pericardium as the sling material. The Arc-to-Arc mini-sling, using bovine pericardium, was the first published report of a mini-sling, in 1999. The technique was identical to the "tension-free tape" operation, midline incision and dissection of the urethra. The ATFP (white line) was identified by blunt dissection, and the mini-sling was sutured to the tendinous arc on both sides with 2 polypropylene 00 sutures. The initial results were encouraging, with 9/10 patients cured at the 6 weeks post-operative visit. However, infection and extrusion of the mini-sling resulted in sling extrusion and removal, with 5 patients remaining cured at 12 months. The Arc-to-Arc mini-sling was a good concept, but failed because of the poor technology available at that time. Further research using new materials and better technology has led to new and safer alternatives for the management of stress urinary incontinence.

Corneal oedema in a unilateral corneal graft patient induced by high Dk mini-scleral contact lens.

PubMed

Guillon, Natalie C; Godfrey, Andrew; Hammond, David S

2018-05-24

Scleral contact lenses are increasingly becoming accepted as the method of choice for visual correction of the irregular cornea. As such, cases have surfaced which demonstrate complications arising from mini-scleral lenses. Identification of these issues and adjusting fitting techniques accordingly is necessary for reducing the risks associated with mini-scleral lens wear. A 58 year old Caucasian female was referred for rigid gas permeable contact lens fitting for correction of right irregular astigmatism post penetrating keratoplasty. After four months of successful mini-scleral contact lens wear, the patient experienced a graft rejection episode and treated accordingly, then refit with a new mini-scleral lens. Five months after the lens refit, the patient presented with complaints of hazy vision, and a diagnosis of lens-induced corneal oedema made. Increased awareness of the potential complications of mini-scleral lenses is necessary to encourage and enforce mini-scleral lens fitting techniques that meet the requirements of minimum vault but adequate protection of the compromised cornea. Copyright © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Mechanical power efficiency of modified turbine blades

NASA Astrophysics Data System (ADS)

Mahmud, Syahir; Sampebatu, Limbran; Kwang, Suendy Ciayadi

2017-01-01

Abstract-The problem of energy crisis has become one of the unsolved issues until today. Indonesia has a lot of non-conventional energy sources that does not utilized effectively yet. For that the available resources must utilized efficiently due to the energy crisis and the growing energy needs. Among the abundant resources of energy, one potential source of energy is hydroelectric energy. This research compares the mechanical power efficiency generated by the Darrieus turbine, Savonius turbine and the Darrieus-Savonius turbine. The comparation of the mechanical power amongst the three turbine starts from the measurement of the water flow rate, water temperature, turbine rotation and force on the shaft on each type of turbine. The comparison will show the mechanical power efficiency of each turbine to find the most efficient turbine that can work optimally. The results show that with 0.637m/s flow velocity and 44.827 Watt of water flow power, the Darrieus-Savonius turbine can generate power equal to 29.927 Watt and shaft force around by 17 N. The Darrieus-Savonius turbine provides around 66.76% efficiency betwen the three turbines; Darrieus turbine, Savonius turbine and the Darrieus-Savonius turbine. Overall, the Darrieus Savonius turbine has the ability to work optimally at the research location.

Apparatus and methods of reheating gas turbine cooling steam and high pressure steam turbine exhaust in a combined cycle power generating system

DOEpatents

Tomlinson, Leroy Omar; Smith, Raub Warfield

2002-01-01

In a combined cycle system having a multi-pressure heat recovery steam generator, a gas turbine and steam turbine, steam for cooling gas turbine components is supplied from the intermediate pressure section of the heat recovery steam generator supplemented by a portion of the steam exhausting from the HP section of the steam turbine, steam from the gas turbine cooling cycle and the exhaust from the HP section of the steam turbine are combined for flow through a reheat section of the HRSG. The reheated steam is supplied to the IP section inlet of the steam turbine. Thus, where gas turbine cooling steam temperature is lower than optimum, a net improvement in performance is achieved by flowing the cooling steam exhausting from the gas turbine and the exhaust steam from the high pressure section of the steam turbine in series through the reheater of the HRSG for applying steam at optimum temperature to the IP section of the steam turbine.

Why are mini-implants lost: the value of the implantation technique!

PubMed

Romano, Fabio Lourenço; Consolaro, Alberto

2015-01-01

The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1) Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2) Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3) Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4) The more precise the lancing procedures, the better the implant placement technique; 5) Self-drilling does not mean higher pressures; 6) Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

VAST 2010 Challenge: Arms Dealings and Pandemics

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

Grinstein, Georges; Konecni, Shawn; Plaisant, Catherine

2010-10-23

The 5th VAST Challenge consisted of three mini-challenges that involved both intelligence analysis and bioinformatics. Teams could solve one, two or all three mini-challenges and assess the overall situation to enter the Grand Challenge. Mini-challenge one involved text reports about people and events giving information about arms dealers, situations in various countries and linkages between different countries. Mini-challenge two involved hospital admission and death records from various countries providing information about the spread of a world wide pandemic. Mini-challenge three involved genetic data to be used to identify the origin of the pandemic and the most dangerous viral mutations. Themore » Grand Challenge was to determine how these various mini-challenges were connected. As always the goal was to analyze the data and provide novel interactive visualizations useful in the analytic process. We received 58 submissions in total and gave 15 awards.« less

Design and Performance Evaluation of a UWB Communication and Tracking System for Mini-AERCam

NASA Technical Reports Server (NTRS)

Barton, Richard J.

2005-01-01

NASA Johnson Space Center (JSC) is developing a low-volume, low-mass, robotic free-flying camera known as Mini-AERCam (Autonomous Extra-vehicular Robotic Camera) to assist the International Space Station (ISS) operations. Mini-AERCam is designed to provide astronauts and ground control real-time video for camera views of ISS. The system will assist ISS crewmembers and ground personnel to monitor ongoing operations and perform visual inspections of exterior ISS components without requiring extravehicular activity (EAV). Mini-AERCam consists of a great number of subsystems. Many institutions and companies have been involved in the R&D for this project. A Mini-AERCam ground control system has been studied at Texas A&M University [3]. The path planning and control algorithms that direct the motions of Mini-AERCam have been developed through the joint effort of Carnegie Mellon University and the Texas Robotics and Automation Center [5]. NASA JSC has designed a layered control architecture that integrates all functions of Mini-AERCam [8]. The research described in this report is part of a larger effort focused on the communication and tracking subsystem that is designed to perform three major tasks: 1. To transmit commands from ISS to Mini-AERCam for control of robotic camera motions (downlink); 2. To transmit real-time video from Mini-AERCam to ISS for inspections (uplink); 3. To track the position of Mini-AERCam for precise motion control. The ISS propagation environment is unique due to the nature of the ISS structure and multiple RF interference sources [9]. The ISS is composed of various truss segments, solar panels, thermal radiator panels, and modules for laboratories and crew accommodations. A tracking system supplemental to GPS is desirable both to improve accuracy and to eliminate the structural blockage due to the close proximity of the ISS which could at times limit the number of GPS satellites accessible to the Mini-AERCam. Ideally, the tracking system will be a passive component of the communication system which will need to operate in a time-varying multipath environment created as the robot camera moves over the ISS structure. In addition, due to many interference sources located on the ISS, SSO, LEO satellites and ground-based transmitters, selecting a frequency for the ISS and Mini-AERCam link which will coexist with all interferers poses a major design challenge. To meet all of these challenges, ultrawideband (UWB) radio technology is being studied for use in the Mini-AERCam communication and tracking subsystem. The research described in this report is focused on design and evaluation of passive tracking system algorithms based on UWB radio transmissions from mini-AERCam.

Residency Mini-fellowships in the PGY-5 Year: Is There Added Value?

PubMed

Shenoy-Bhangle, Anuradha S; Eisenberg, Ronald L; Fineberg, Tabitha; Slanetz, Priscilla J

2018-06-01

With the restructuring of radiology board certification, many residencies created PGY-5 "mini-fellowships," during which residents spend focused time pursuing advanced subspecialty training or developing nonclinical skills in leadership, health policy and health-care economics, education, quality improvement, informatics, research, or global health. We surveyed graduates of an academic diagnostic radiology residency to assess the relative value and impact of PGY-5 mini-fellowships on career satisfaction and success. From 2012 to 2016, 39 radiology residents at our institution were offered the opportunity to pursue a 3- to 6-month mini-fellowship during the PGY-5 year. Thirty of 39 radiology residents (77%) participated, whereas 9 of 39 (23%) opted out. Of 39 residents, 13 completed two clinical mini-fellowships, 3 completed research mini-fellowships only, and 14 completed one nonclinical and one clinical mini-fellowship. Through SurveyMonkey, 23 of 39 residents (59%) responded to a questionnaire that collected basic demographic information and asked respondents about the value of this experience as it relates to fellowship choice and career using a five-point Likert scale. Of 23 respondents (14 male, 8 female,1 not specified), 78.3% practice in an academic university-based setting, with 8.7% in a community-based hospital practice, 4.3% in the veterans system, and 4.3% in a private practice setting. Of 23 respondents, the most popular clinical mini-fellowships were magnetic resonance imaging (31.6%), neuroradiology (21.1%), and interventional radiology (15.8%). For nonclinical mini-fellowships, the most popular were research (10.5%), education (10.5%), global health (5.3%), and healthcare economics (5.3%). Of 23 respondents who did mini-fellowships, 95% felt that the mini-fellowship prepared them well for their career, 85% felt it gave them the necessary skills to succeed, 85% cited that it gave them additional skills beyond their peers, and 40% felt it helped them create a life-long connection to a mentor. Ninety-five percent of respondents would choose to do the mini-fellowship again. Respondents suggested increasing the duration to 6-9 months and to develop a more structured curriculum and mentorship component. Only one respondent felt that the nonclinical mini-fellowship took away time from furthering clinical skills. Graduates of a university-affiliated academic radiology residency who participated in clinical and nonclinical mini-fellowships during the PGY-5 year of residency greatly value this experience and uniformly recommend that this type of program continue to be offered to trainees given its ability to develop skills perceived to be vital to ultimate career satisfaction and success. Published by Elsevier Inc.

Method of making an aero-derivative gas turbine engine

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

Wiebe, David J.

A method of making an aero-derivative gas turbine engine (100) is provided. A combustor outer casing (68) is removed from an existing aero gas turbine engine (60). An annular combustor (84) is removed from the existing aero gas turbine engine. A first row of turbine vanes (38) is removed from the existing aero gas turbine engine. A can annular combustor assembly (122) is installed within the existing aero gas turbine engine. The can annular combustor assembly is configured to accelerate and orient combustion gasses directly onto a first row of turbine blades of the existing aero gas turbine engine. Amore » can annular combustor assembly outer casing (108) is installed to produce the aero-derivative gas turbine engine (100). The can annular combustor assembly is installed within an axial span (85) of the existing aero gas turbine engine vacated by the annular combustor and the first row of turbine vanes.« less

Er:YAG laser, piezosurgery, and surgical drill for bone decortication during orthodontic mini-implant insertion: primary stability analysis-an animal study.

PubMed

Matys, Jacek; Flieger, Rafał; Tenore, Gianluca; Grzech-Leśniak, Kinga; Romeo, Umberto; Dominiak, Marzena

2018-04-01

It is important to identify factors that affect primary stability of orthodontic mini-implants because it determines the success of treatment. We assessed mini-implant primary stability (initial mechanical engagement with the bone) placed in pig jaws. We also assessed mini-implant insertion failure rate (mini-implant fracture, mini-implants to root contact). A total of 80 taper-shaped mini-implants (Absoanchor® Model SH1312-6; Dentos Inc., Daegu, Korea) 6 mm long with a diameter of 1.1 mm were used. Bone decortication was made before mini-implant insertion by means of three different methods: Group G1: Er:YAG laser (LiteTouch®, Light Instruments, Yokneam, Israel) at energy of 300 mJ, frequency 25 Hz, fluence 38.2 J/cm2, cooling 14 ml/min, tip 1.0 × 17 mm, distance 1 mm, time of irradiation 6 s; Group G2: drill (Hager & Meisinger GmbH, Hansemannstr, Germany); Group G3: piezosurgery (Piezotom Solo, Acteon, NJ, USA). In G4 group (control), mini-implants were driven by a self-drilling method. The primary stability of mini-implants was assessed by measuring damping characteristics between the implant and the tapping head of Periotest device (Gulden-Medizinteknik, Eschenweg, Modautal, Germany). The results in range between - 8 to + 9 allowed immediate loading. Significantly lower Periotest value was found in the control group (mean 0.59 ± 1.57, 95% CI 0.7, 2.4) as compared with Er:YAG laser (mean 4.44 ± 1.64, 95% CI 3.6, 5.3), piezosurgery (mean 17.92 ± 2.73, 95% CI 16.5, 19.3), and a drill (mean 5.91 ± 1.52, 95% CI 5.2, 6.6) (p < 0.05). The highest failure rate (33.3%) during mini-implant insertion was noted for self-drilling method (G4) as compared with G1, G2, and G3 groups (p < 0.05). The small diameter decortication by Er:YAG laser appeared to provide better primary stability as compared to drill and piezosurgery. Decortication of the cortical bone before mini-implant insertion resulted in reduced risk of implant fracture or injury of adjacent teeth. The high initial stability with a smaller diameter of the mini-implant resulted in increased risk of fracture, especially for a self-drilling method.

The Simulation Study of Horizontal Axis Water Turbine Using Flow Simulation Solidworks Application

NASA Astrophysics Data System (ADS)

Prasetyo, H.; Budiana, EP; Tjahjana, DDDP; Hadi, S.

2018-02-01

The design of Horizontal Axis Water Turbine in pico hydro power plants involves many parameters. To simplify that, usually using computer simulation is applied. This research performs simulation process variation on turbine blade number, turbine blade curvature angle, turbine bucket angle and blocking system tilt angle. Those four variations were combined in order to obtain the best design of turbine. The study used Flow Simulation Solidworks application, and obtain data on turbine speed, pressure, force, and torque. However, this research focused on turbine torque value. The best design of turbine was obtained in the turbine with 6 blades, blade curvature angle of 65° and bucket angle of 10°, and blocking system tilt angle of 40°. In the best turbine, the produced torque value was 8.464 Nm.

Comparative analysis of numerical and experimental data of orthodontic mini-implants.

PubMed

Chatzigianni, Athina; Keilig, Ludger; Duschner, Heinz; Götz, Hermann; Eliades, Theodore; Bourauel, Christoph

2011-10-01

The purpose of this study was to compare numerical simulation data derived from finite element analysis (FEA) to experimental data on mini-implant loading. Nine finite element (FE) models of mini-implants and surrounding bone were derived from corresponding experimental specimens. The animal bone in the experiment consisted of bovine rib. The experimental groups were based on implant type, length, diameter, and angle of insertion. One experimental specimen was randomly selected from each group and was digitized in a microCT scanner. The FE models consisted of bone pieces containing Aarhus mini-implants with dimensions 1.5 × 7 mm and 1.5 × 9 mm or LOMAS mini-implants (dimensions 1.5 × 7 mm, 1.5 × 9 mm, and 2 × 7 mm). Mini-implants were inserted in two different ways, perpendicular to the bone surface or at 45 degrees to the direction of the applied load. Loading and boundary conditions in the FE models were adjusted to match the experimental situation, with the force applied on the neck of the mini-implants, along the mesio-distal direction up to a maximum of 0.5 N. Displacement and rotation of mini-implants after force application calculated by FEA were compared to previously recorded experimental deflections of the same mini-implants. Analysis of data with the Altman-Bland test and the Youden plot demonstrated good agreement between numerical and experimental findings (P = not significant) for the models selected. This study provides further evidence of the appropriateness of the FEA as an investigational tool in relevant research.

Comparison of retrograde intrarenal surgery and mini-percutaneous nephrolithotomy in management of lower-pole renal stones with a diameter of smaller than 15 mm.

PubMed

Kirac, Mustafa; Bozkurt, Ömer Faruk; Tunc, Lutfi; Guneri, Cagri; Unsal, Ali; Biri, Hasan

2013-06-01

The aim of this study was to compare the outcomes of retrograde intrarenal surgery (RIRS) and miniaturized percutaneous nephrolithotomy (mini-PNL) in management of lower-pole renal stones with a diameter smaller than 15 mm. Between December 2009 and July 2012, the patients with the diagnosis of lower-pole stones were evaluated by ultrasonography, intravenous pyelography and computed tomography. The records of 73 evaluable patients who underwent mini-PNL (n = 37) or RIRS (n = 36) for lower-pole (LP) stones with diameter smaller than 15 mm were reviewed retrospectively. Of the 73 patients, 37 underwent mini-PNL and 36 underwent RIRS. The stone-free rates were 89.1 and 88.8 % for mini-PNL and RIRS groups, respectively. The mean operation time was 53.7 ± 14.5 in the mini-PNL group but 66.4 ± 15.8 in the RIRS group (P = 0.01). The mean fluoroscopy times and hospitalization times were significantly higher in the mini-PNL group. There was no major complication in any patient. RIRS and mini-PNL are safe and effective methods for treatment of LP calculi with a diameter smaller than 15 mm. RIRS is a non-invasive and feasible treatment option, and has also short hospitalization time, low morbidity and complication rate. It may be an alternative of mini-PNL in the treatment LP calculi with smaller than 15 mm.

Are Ducted Mini-Splits Worth It?

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

Winkler, Jonathan M; Maguire, Jeffrey B; Metzger, Cheryn E.

Ducted mini-split heat pumps are gaining popularity in some regions of the country due to their energy-efficient specifications and their ability to be hidden from sight. Although product and install costs are typically higher than the ductless mini-split heat pumps, this technology is well worth the premium for some homeowners who do not like to see an indoor unit in their living area. Due to the interest in this technology by local utilities and homeowners, the Bonneville Power Administration (BPA) has funded the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL) to develop capabilities within themore » Building Energy Optimization (BEopt) tool to model ducted mini-split heat pumps. After the fundamental capabilities were added, energy-use results could be compared to other technologies that were already in BEopt, such as zonal electric resistance heat, central air source heat pumps, and ductless mini-split heat pumps. Each of these technologies was then compared using five prototype configurations in three different BPA heating zones to determine how the ducted mini-split technology would perform under different scenarios. The result of this project was a set of EnergyPlus models representing the various prototype configurations in each climate zone. Overall, the ducted mini-split heat pumps saved about 33-60% compared to zonal electric resistance heat (with window AC systems modeled in the summer). The results also showed that the ducted mini-split systems used about 4% more energy than the ductless mini-split systems, which saved about 37-64% compared to electric zonal heat (depending on the prototype and climate).« less

Mini-Split Heat Pumps Multifamily Retrofit Feasibility Study

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

Dentz, Jordan; Podorson, David; Varshney, Kapil

Mini-split heat pumps can provide space heating and cooling in many climates and are relatively affordable. These and other features make them potentially suitable for retrofitting into multifamily buildings in cold climates to replace electric resistance heating or other outmoded heating systems. This report investigates the suitability of mini-split heat pumps for multifamily retrofits. Various technical and regulatory barriers are discussed and modeling was performed to compare long-term costs of substituting mini-splits for a variety of other heating and cooling options. A number of utility programs have retrofit mini-splits in both single family and multifamily residences. Two such multifamily programsmore » are discussed in detail.« less

Replacing Resistance Heating with Mini-Split Heat Pumps, Sharon, Connecticut (Fact Sheet)

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

Not Available

Mini-split heat pumps can provide space heating and cooling in many climates and are relatively affordable. These and other features make them potentially suitable for retrofitting into multifamily buildings in cold climates to replace electric resistance heating or other outmoded heating systems. This report investigates the suitability of mini-split heat pumps for multifamily retrofits. Various technical and regulatory barriers are discussed and modeling was performed to compare long-term costs of substituting mini-splits for a variety of other heating and cooling options. A number of utility programs have retrofit mini-splits in both single family and multifamily residences. Two such multifamily programsmore » are discussed in detail.« less

Mini-Split Heat Pumps Multifamily Retrofit Feasibility Study

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

Dentz, J.; Podorson, D.; Varshney, K.

2014-05-01

Mini-split heat pumps can provide space heating and cooling in many climates and are relatively affordable. These and other features make them potentially suitable for retrofitting into multifamily buildings in cold climates to replace electric resistance heating or other outmoded heating systems. This report investigates the suitability of mini-split heat pumps for multifamily retrofits. Various technical and regulatory barriers are discussed and modeling was performed to compare long-term costs of substituting mini-splits for a variety of other heating and cooling options. A number of utility programs have retrofit mini-splits in both single family and multifamily residences. Two such multifamily programsmore » are discussed in detail.« less

Effect of Air Cooling of Turbine Disk on Power and Efficiency of Turbine from Turbo Engineering Corporation TT13-18 Turbosupercharger.

NASA Technical Reports Server (NTRS)

Berkey, William E.

1949-01-01

An investigation was conducted to determine the effect of turbine-disk cooling with air on the efficiency and the power output of the radial-flow turbine from the Turbo Engineering Corporation TT13-18 turbosupercharger. The turbine was operated at a constant range of ratios of turbine-inlet total pressure to turbine-outlet static pressure of 1,5 and 2.0, turbine-inlet total pressure of 30 inches mercury absolute, turbine-inlet total temperature of 12000 to 20000 R, and rotor speeds of 6000 to 22,000 rpm, Over the normal operating range of the turbine, varying the corrected cooling-air weight flow from approximately 0,30 to 0.75 pound per second produced no measurable effect on the corrected turbine shaft horsepower or the turbine shaft adiabatic efficiency. Varying the turbine-inlet total temperature from 12000 to 20000 R caused no measurable change in the corrected cooling-air weight flow. Calculations indicated that the cooling-air pumping power in the disk passages was small and was within the limits of the accuracy of the power measurements. For high turbine power output, the power loss to the compressor for compressing the cooling air was approximately 3 percent of the total turbine shaft horsepower.

Environmental Assessment: Proposed Construction of Army and Air Force Exchange Service Mini-Mall

DTIC Science & Technology

2003-10-01

fast food style restaurant would be accommodated in the mini-mall. Data on electrical consumption for the Burger King restaurant at MAFB (Building...MAFB-Gunter Annex. Assuming the new restaurant in the mini-mall consumes approximately the same quantity of electricity annually as the Burger King ...in the mini-mall. Data on natural gas consumption for the Burger King restaurant at MAFB (Building 1087) in FY 2001 reveals that this facility

Developments in Miniaturized Laser Heterodyne Radiometer (mini-LHR) construction for groundtruth measurements of CH4 and CO2 in harsh terrain

NASA Astrophysics Data System (ADS)

DiGregorio, A.; Wilson, E. L.; Hoffman, C.; Grunberg, C.; Mao, J.; Ramanathan, A. K.

2016-12-01

We present an updated, ruggedized design of NASA Goddard Space Flight Center's Miniaturized Laser Heterodyne Radiometer (mini-LHR), and the results of testing in the Bonanza Creek Research Forest. The mini-LHR is a passive variation of typical heterodyne radiometry instruments, designed to work in tandem with the AERONET sun photometer for collection of column methane (CH4) and carbon dioxide (CO2) in harsh environments. Advancements in the development of the Cube-Sat version of the mini-LHR have allowed a more than 50% reduction in size, weight, and power usage of the mini-LHR. Now small enough to fit in a medium handbag, the mini-LHR can be run off of a small 35 Watt solar panel and backup battery for continuous measurement. Using a touch-screen control interface built off of a Raspberry Pi, the updated mini-LHR is capable of data collection and preliminary data processing, even without internet, cellular, or satellite connectivity. The improvements made to the mini-LHR were tested in a field campaign in May 2016 funded under NASA's IDS program to track CH4 and CO2 emissions above thawing permafrost. In addition to being a comprehensive study of methane release from thawing permafrost, this pilot study tested the ruggedization and functionality of the instrument in three different environments- a black spruce forest, collapsed scar bog, and fen.

Turbine system and adapter

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

Hogberg, Nicholas Alvin; Garcia-Crespo, Andres Jose

A turbine system and adapter are disclosed. The adapter includes a turbine attachment portion having a first geometry arranged to receive a corresponding geometry of a wheelpost of a turbine rotor, and a bucket attachment portion having a second geometry arranged to receive a corresponding geometry of a root portion of a non-metallic turbine bucket. Another adapter includes a turbine attachment portion arranged to receive a plurality of wheelposts of a turbine rotor, and a bucket attachment portion arranged to receive a plurality of non-metallic turbine buckets having single dovetail configuration root portions. The turbine system includes a turbine rotormore » wheel configured to receive metal buckets, at least one adapter secured to at least one wheelpost on the turbine rotor wheel, and at least one non-metallic bucket secured to the at least one adapter.« less

Feasibility Study for a Practical High Rotor Tip Clearance Turbine.

DTIC Science & Technology

GAS TURBINE BLADES ), (* TURBINE BLADES , TOLERANCES(MECHANICS)), (* TURBOFAN ENGINES , GAS TURBINES , AXIAL FLOW TURBINES , AXIAL FLOW TURBINE ROTORS...AERODYNAMIC CONFIGURATIONS, LEAKAGE(FLUID), MEASUREMENT, TEST METHODS, PERFORMANCE( ENGINEERING ), MATHEMATICAL PREDICTION, REDUCTION, PRESSURE, PREDICTIONS, NOZZLE GAS FLOW, COMBUSTION CHAMBER GASES, GAS FLOW.

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

Investigation of turbine ventilator performance after added wind cup for room exhaust air applications

NASA Astrophysics Data System (ADS)

Harun, D.; Zulfadhli; Akhyar, H.

2018-05-01

The turbine ventilator is a wind turbine with a vertical axis that has a combined function of the wind turbine and a suction fan. In this study, the turbine ventilator modified by adding a wind cup on the top (cap) turbine ventilator. The purpose of this experiment is to investigated the effect of the addition of wind cup on the turbine ventilator. Turbine ventilator used is type v30 and wind cup with diameter 77 mm. The experiment was conducted using a triangular pentagon model space chamber which was cut off to place the ventilator turbine ventilation cup with a volume of 0.983 m3 (equivalent to 1 mm3). The results of this study indicate that at an average wind speed of 1.8 m/s, the rotation of the turbine produced without a wind cup is 60.6 rpm while with the addition of a wind cup in the turbine ventilator is 69 rpm. The average increase of rotation turbine after added win cup is 8.4 rpm and the efficiency improvement of turbine ventilator is 1.7 %.

MINI PILOT PLANT FOR DRINKING WATER RESEARCH

EPA Science Inventory

The Water Supply & Water Resources Division (WSWRD) has constructed 2 mini-pilot plant systems used to conduct drinking water research. These two systems each have 2 parallel trains for comparative research. The mini-pilot plants are small conventional drinking water treatment ...

Three-dimensional Numerical Analysis on Blade Response of Vertical Axis Tidal Current Turbine Under Operational Condition

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

Li, Ye; Karri, Naveen K.; Wang, Qi

Tidal power as a large-scale renewable source of energy has been receiving significant attention recently because of its advantages over the wind and other renewal energy sources. The technology used to harvest energy from tidal current is called a tidal current turbine. Though some of the principles of wind turbine design are applicable to tidal current turbines, the design of latter ones need additional considerations like cavitation damage, corrosion etc. for the long-term reliability of such turbines. Depending up on the orientation of axis, tidal current turbines can be classified as vertical axis turbines or horizontal axis turbines. Existing studiesmore » on the vertical axis tidal current turbine focus more on the hydrodynamic aspects of the turbine rather than the structural aspects. This paper summarizes our recent efforts to study the integrated hydrodynamic and structural aspects of the vertical axis tidal current turbines. After reviewing existing methods in modeling tidal current turbines, we developed a hybrid approach that combines discrete vortex method -finite element method that can simulate the integrated hydrodynamic and structural response of a vertical axis turbine. This hybrid method was initially employed to analyze a typical three-blade vertical axis turbine. The power coefficient was used to evaluate the hydrodynamic performance, and critical deflection was considered to evaluate the structural reliability. A sensitivity analysis was also conducted with various turbine height-to-radius ratios. The results indicate that both the power output and failure probability increase with the turbine height, suggesting a necessity for optimal design. An attempt to optimize a 3-blade vertical axis turbine design with hybrid method yielded a ratio of turbine height to radius (H/R) about 3.0 for reliable maximum power output.« less

Development of Advanced Seals for Industrial Turbine Applications

NASA Astrophysics Data System (ADS)

Chupp, Raymond E.; Aksit, Mahmut F.; Ghasripoor, Farshad; Turnquist, Norman A.; Dinc, Saim; Mortzheim, Jason; Demiroglu, Mehmet

2002-10-01

A critical area being addressed to improve industrial turbine performance is reducing the parasitic leakage flows through the various static and dynamic seals. Implementation of advanced seals into General Electric (GE) industrial turbines has progressed well over the last few years with significant operating performance gains achieved. Advanced static seals have been placed in gas turbine hot gas-path junctions and steam turbine packing ring segment end gaps. Brush seals have significantly decreased labyrinth seal leakages in gas turbine compressors and turbine interstages, steam turbine interstage and end packings, industrial compressor shaft seals, and generator seals. Abradable seals are being developed for blade-tip locations in various turbine locations. This presentation summarizes the status of advanced seal development for industrial turbines at GE.

Ortho-Rectification of Narrow Band Multi-Spectral Imagery Assisted by Dslr RGB Imagery Acquired by a Fixed-Wing Uas

NASA Astrophysics Data System (ADS)

Rau, J.-Y.; Jhan, J.-P.; Huang, C.-Y.

2015-08-01

Miniature Multiple Camera Array (MiniMCA-12) is a frame-based multilens/multispectral sensor composed of 12 lenses with narrow band filters. Due to its small size and light weight, it is suitable to mount on an Unmanned Aerial System (UAS) for acquiring high spectral, spatial and temporal resolution imagery used in various remote sensing applications. However, due to its wavelength range is only 10 nm that results in low image resolution and signal-to-noise ratio which are not suitable for image matching and digital surface model (DSM) generation. In the meantime, the spectral correlation among all 12 bands of MiniMCA images are low, it is difficult to perform tie-point matching and aerial triangulation at the same time. In this study, we thus propose the use of a DSLR camera to assist automatic aerial triangulation of MiniMCA-12 imagery and to produce higher spatial resolution DSM for MiniMCA12 ortho-image generation. Depending on the maximum payload weight of the used UAS, these two kinds of sensors could be collected at the same time or individually. In this study, we adopt a fixed-wing UAS to carry a Canon EOS 5D Mark2 DSLR camera and a MiniMCA-12 multi-spectral camera. For the purpose to perform automatic aerial triangulation between a DSLR camera and the MiniMCA-12, we choose one master band from MiniMCA-12 whose spectral range has overlap with the DSLR camera. However, all lenses of MiniMCA-12 have different perspective centers and viewing angles, the original 12 channels have significant band misregistration effect. Thus, the first issue encountered is to reduce the band misregistration effect. Due to all 12 MiniMCA lenses being frame-based, their spatial offsets are smaller than 15 cm and all images are almost 98% overlapped, we thus propose a modified projective transformation (MPT) method together with two systematic error correction procedures to register all 12 bands of imagery on the same image space. It means that those 12 bands of images acquired at the same exposure time will have same interior orientation parameters (IOPs) and exterior orientation parameters (EOPs) after band-to-band registration (BBR). Thus, in the aerial triangulation stage, the master band of MiniMCA-12 was treated as a reference channel to link with DSLR RGB images. It means, all reference images from the master band of MiniMCA-12 and all RGB images were triangulated at the same time with same coordinate system of ground control points (GCP). Due to the spatial resolution of RGB images is higher than the MiniMCA-12, the GCP can be marked on the RGB images only even they cannot be recognized on the MiniMCA images. Furthermore, a one meter gridded digital surface model (DSM) is created by the RGB images and applied to the MiniMCA imagery for ortho-rectification. Quantitative error analyses show that the proposed BBR scheme can achieve 0.33 pixels of average misregistration residuals length and the co-registration errors among 12 MiniMCA ortho-images and between MiniMCA and Canon RGB ortho-images are all less than 0.6 pixels. The experimental results demonstrate that the proposed method is robust, reliable and accurate for future remote sensing applications.

Experimental evaluation of a translating nozzle sidewall radial turbine

NASA Technical Reports Server (NTRS)

Roelke, Richard J.; Rogo, Casimir

1987-01-01

An experimental performance evaluation was made of two movable sidewall variable area radial turbines. The turbine designs were representative of the gas generator turbine of a variable flow capacity rotorcraft engine. The first turbine was an uncooled design while the second turbine had a cooled nozzle but an uncooled rotor. The cooled nozzle turbine was evaluated both with and without coolant flow. The test results showed that the movable nozzle wall is a viable and efficient means to effectively control the flow capacity of a radial turbine. Peak efficiencies of the second turbine with and without nozzle coolant were 86.5 and 88 percent respectively. These values are comparable to pivoting vane variable geometry turbines; however, the decrease in efficiency as the flow was varied from the design value was much less for the movable wall turbine. Several design improvements which should increase the turbine efficiency one or two more points are identified. These design improvements include reduced leakage losses and relocation of the vane coolant ejection holes to reduce mainstream disturbance.

The system design and performance test of hybrid vertical axis wind turbine

NASA Astrophysics Data System (ADS)

Dwiyantoro, Bambang Arip; Suphandani, Vivien

2017-04-01

Vertical axis wind turbine is a tool that is being developed to generate energy from wind. One cause is still little use of wind energy is the design of wind turbines that are less precise. Therefore in this study will be developed the system design of hybrid vertical axis wind turbine and tested performance with experimental methods. The design of hybrid turbine based on a straight bladed Darrieus turbine along with a double step Savonius turbine. The method used to design wind turbines is by studying literature, analyzing the critical parts of a wind turbine and the structure of the optimal design. Wind turbine prototype of the optimal design characteristic tests in the wind tunnel experimentally by varying the speed of the wind. From the experimental results show that the greater the wind speed, the greater the wind turbine rotation and torque is raised. The hybrid vertical axis wind turbine has much better self-starting and better conversion efficiency.

Coordinated Control of Cross-Flow Turbines

NASA Astrophysics Data System (ADS)

Strom, Benjamin; Brunton, Steven; Polagye, Brian

2016-11-01

Cross-flow turbines, also known as vertical-axis turbines, have several advantages over axial-flow turbines for a number of applications including urban wind power, high-density arrays, and marine or fluvial currents. By controlling the angular velocity applied to the turbine as a function of angular blade position, we have demonstrated a 79 percent increase in cross-flow turbine efficiency over constant-velocity control. This strategy uses the downhill simplex method to optimize control parameter profiles during operation of a model turbine in a recirculating water flume. This optimization method is extended to a set of two turbines, where the blade motions and position of the downstream turbine are optimized to beneficially interact with the coherent structures in the wake of the upstream turbine. This control scheme has the potential to enable high-density arrays of cross-flow turbines to operate at cost-effective efficiency. Turbine wake and force measurements are analyzed for insight into the effect of a coordinated control strategy.

Computational examination of utility scale wind turbine wake interactions

DOE PAGES

Okosun, Tyamo; Zhou, Chenn Q.

2015-07-14

We performed numerical simulations of small, utility scale wind turbine groupings to determine how wakes generated by upstream turbines affect the performance of the small turbine group as a whole. Specifically, various wind turbine arrangements were simulated to better understand how turbine location influences small group wake interactions. The minimization of power losses due to wake interactions certainly plays a significant role in the optimization of wind farms. Since wind turbines extract kinetic energy from the wind, the air passing through a wind turbine decreases in velocity, and turbines downstream of the initial turbine experience flows of lower energy, resultingmore » in reduced power output. Our study proposes two arrangements of turbines that could generate more power by exploiting the momentum of the wind to increase velocity at downstream turbines, while maintaining low wake interactions at the same time. Furthermore, simulations using Computational Fluid Dynamics are used to obtain results much more quickly than methods requiring wind tunnel models or a large scale experimental test.« less

History and current status of mini-invasive thoracic surgery

PubMed Central

He, Jianxing

2011-01-01

Mini-invasive thoracic technique mainly refers to a technique involving the significant reduction of the chest wall access-related trauma. Notably, thoracoscope is the chief representative. The development of thoracoscope technique is characterized by: developing from direct peep to artificial lighting, then combination with image and video technique in equipments; technically developing from diagnostic to therapeutic approaches; developing from simpleness to complexity in application scope; and usually developing together with other techniques. At present, the widely used mini-invasive thoracic surgery refers to the mini-open thoracic surgery performed mainly by using some instruments to control target tissues and organs based on the vision associated with multi-limb coordination, which may be hand-assisted if necessary. The mini-invasive thoracic surgery consists of three approaches including video-assisted thoracic surgery (VATS), video-assisted Hybrid and hand-assisted VATS. So far the mini-invasive thoracic technique has achieved great advances due to the development in instruments of mini-invasive thoracic surgery which has the following features: instruments of mini-invasive thoracic surgery appear to be safe and practical, and have successive improvement and diversification in function; the specific instruments of open surgeries has been successively developed into dedicated instruments of endoscopic surgery; the application of endoscopic mechanical suture device generates faster fragmentation and reconstruction of organ tissues; the specific delicated instruments of endoscopic surgery have rapid development and application; and the simple instruments structurally similar to the conventional instruments are designed according to the mini-incison. In addition, the mini-invasive thoracic technique is widely used in five aspects including diseases of pleura membrane and chest wall, lung diseases, esophageal diseases, mediastinal diseases and heart diseases. However, there remain many problems in specifications and trainings, economic cost, conservation and innovation. Therefore, particular attention should be paid to these problems. Nevertheless, the promotion of thoracic surgery appears promising in the future. PMID:22263074

Mandibular Overdentures Retained by Two Mini-Implants: A Seven-Year Retention and Satisfaction Study.

PubMed

Catalán, Alfonso; Martínez, Alejandra; Marchesani, Francisco; González, Urcesino

2016-07-01

Patients with atrophic edentulous ridges generally have problems with retention, therapeutic satisfaction, and comfort with their complete dentures. An alternative treatment to assist in improving retention and stability involves the use of mini-implants. The aim of this study was to evaluate the retention of mandibular overdentures connected to two mini-implants and overall patient satisfaction with them. Seven patients with atrophic mandibular ridges (Type 4D Misch classification), aged 62 to 74 years old were rehabilitated with complete dentures. In each patient, two mini-implants measuring 15 or 13 mm in length and 1.8 mm in diameter were placed. After 15 days, overdentures were connected to the mini-implants with O-ring attachments. In each patient, retention of the overdentures was measured, and a survey of therapeutic satisfaction before and after connection to the mini-implants was administered. Prosthesis retention was measured with a digital dynamometer at 1 month, 6 months, and 2, 3, 5, and 7 years after mini-implant placement. Patient satisfaction was assessed with a survey. Data were analyzed with Student's t-test (satisfaction survey) and the Friedman test (retention measurements and satisfaction survey). The initial retention values (0.34 to 0.63 N without mini-implants) varied significantly (p ≤ 0.050). These values were less than the subsequent measurements of 3.92 to 9.64 N, taken after placement of the mini-implants and connecting them to the dentures. Satisfaction was good to very good over the 7-year observation period. Mucosa and peri-implant bone showed no pathological changes. In this limited sample size clinical study the results indicated that after connecting mandibular overdentures to two mini-implants, patient satisfaction significantly increased and retention significantly improved during the 7-year observation period. © 2015 by the American College of Prosthodontists.

Flexible Ureterorenoscopy versus Mini-Percutaneous Nephrolithotomy for the Treatment of Renal Stones.

PubMed

Ergin, Giray; Kirac, Mustafa; Kopru, Burak; Ebiloglu, Turgay; Biri, Hasan

2018-04-22

To compare the pain status and stone free rates of flexible ureterorenoscopy (F-URS) versus mini-percutaneousnephrolithotomy (mini-PNL) for the treatment of 1-to 2-cm renal stones. This study was retrospectively designed with match paired method. Between January 2013 and December 2016, 387 patients underwent stone surgery for renal stones, 45 patients underwent FURS and 45 patients underwent mini-PNL. 90 patients were divided into two groups according to the surgical procedures. Group 1 patients underwent F-URS, and Group 2 patients underwent mini-PNL. During the intraoperative andpostoperative periods, pain management for all patients was standardized. Pain scores were determined using a visual analogue scale (VAS) completed at 2, 6, 12 and 24 hours postoperatively. The stone free status, hemoglobin levels, fluoroscopy time (FT), operation time (OT), hospitalization time (HT), return to work time (RWT), and complications were noted for each patient. Of all patients, the mean age was 41.1 ± 12.1 years and the mean stone size was 13.9 ± 2.9 mm. The VAS scores were significantly higher in the mini-PNL group at 2, 6, 12 and 24 hours (P < .05). The stone-free status and complication rates were similar between the two groups (P > .05); however, the hemoglobin decreases and the fluoroscopy, operation, hospitalization and return to work times were higher in the mini-PNL group than in the F-URS group (P < .05). F-URS is less painful than mini-PNL for the treatment of 1- to 2-cm renal stones. However, the stone free rate is similar between the two procedures while mini-PNL is superior in terms of fluoroscopy, operation, hospitalization and return to work duration. We think that F-URS is more comfortable and less painful than mini-PNL and achieves a similar stone free rate for the treatment of 1- to 2-cm renal stones.

Wind Turbine Control Systems | Wind | NREL

Science.gov Websites

Turbine Control Systems Wind Turbine Control Systems Advanced wind turbine controls can reduce the loads on wind turbine components while capturing more wind energy and converting it into electricity turbines. A photo of a wind turbine against blue sky with white blades on their sides in the foreground

A Measurement of the muon neutrino charged current quasielastic interaction and a test of Lorentz violation with the MiniBooNE experiment

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

Katori, Teppei

2008-12-01

The Mini-Booster neutrino experiment (MiniBooNE) at Fermi National Accelerator Laboratory (Fermilab) is designed to search for v μ → v e appearance neutrino oscillations. Muon neutrino charged-current quasi-elastic (CCQE) interactions (v μ + n → μ + p) make up roughly 40% of our data sample, and it is used to constrain the background and cross sections for the oscillation analysis. Using high-statistics MiniBooNE CCQE data, the muon-neutrino CCQE cross section is measured. The nuclear model is tuned precisely using the MiniBooNE data. The measured total cross section is σ = (1.058 ± 0.003 (stat) ± 0.111 (syst)) x 10more » -38 cm 2 at the MiniBooNE muon neutrino beam energy (700-800 MeV). v e appearance candidate data is also used to search for Lorentz violation. Lorentz symmetry is one of the most fundamental symmetries in modern physics. Neutrino oscillations offer a new method to test it. We found that the MiniBooNE result is not well-described using Lorentz violation, however further investigation is required for a more conclusive result.« less

Do dual-thread orthodontic mini-implants improve bone/tissue mechanical retention?

PubMed

Lin, Yang-Sung; Chang, Yau-Zen; Yu, Jian-Hong; Lin, Chun-Li

2014-12-01

The aim of this study was to understand whether the pitch relationship between micro and macro thread designs with a parametrical relationship in a dual-thread mini-implant can improve primary stability. Three types of mini-implants consisting of single-thread (ST) (0.75 mm pitch in whole length), dual-thread A (DTA) with double-start 0.375 mm pitch, and dual-thread B (DTB) with single-start 0.2 mm pitch in upper 2-mm micro thread region for performing insertion and pull-out testing. Histomorphometric analysis was performed in these specimens in evaluating peri-implant bone defects using a non-contact vision measuring system. The maximum inserted torque (Tmax) in type DTA was found to be the smallest significantly, but corresponding values found no significant difference between ST and DTB. The largest pull-out strength (Fmax) in the DTA mini-implant was found significantly greater than that for the ST mini-implant regardless of implant insertion orientation. Mini-implant engaged the cortical bone well as observed in ST and DTA types. Dual-thread mini-implant with correct micro thread pitch (parametrical relationship with macro thread pitch) in the cortical bone region can improve primary stability and enhanced mechanical retention.

Psychometric Evaluation of the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID).

PubMed

Duncan, Laura; Georgiades, Kathy; Wang, Li; Van Lieshout, Ryan J; MacMillan, Harriet L; Ferro, Mark A; Lipman, Ellen L; Szatmari, Peter; Bennett, Kathryn; Kata, Anna; Janus, Magdalena; Boyle, Michael H

2017-12-04

The goals of the study were to examine test-retest reliability, informant agreement and convergent and discriminant validity of nine DSM-IV-TR psychiatric disorders classified by parent and youth versions of the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID). Using samples drawn from the general population and child mental health outpatient clinics, 283 youth aged 9 to 18 years and their parents separately completed the MINI-KID with trained lay interviewers on two occasions 7 to 14 days apart. Test-retest reliability estimates based on kappa (κ) went from 0.33 to 0.79 across disorders, samples and informants. Parent-youth agreement on disorders was low (average κ = 0.20). Confirmatory factor analysis provided evidence supporting convergent and discriminant validity. The MINI-KID disorder classifications yielded estimates of test-retest reliability and validity comparable to other standardized diagnostic interviews in both general population and clinic samples. These findings, in addition to the brevity and low administration cost, make the MINI-KID a good candidate for use in epidemiological research and clinical practice. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Surgical positioning of orthodontic mini-implants with guides fabricated on models replicated with cone-beam computed tomography.

PubMed

Kim, Seong-Hun; Choi, Yong-Suk; Hwang, Eui-Hwan; Chung, Kyu-Rhim; Kook, Yoon-Ah; Nelson, Gerald

2007-04-01

This article illustrates a new surgical guide system that uses cone-beam computed tomography (CBCT) images to replicate dental models; surgical guides for the proper positioning of orthodontic mini-implants were fabricated on the replicas, and the guides were used for precise placement. The indications, efficacy, and possible complications of this method are discussed. Patients who were planning to have orthodontic mini-implant treatment were recruited for this study. A CBCT system (PSR 9000N, Asahi Roentgen, Kyoto, Japan) was used to acquire virtual slices of the posterior maxilla that were 0.1 to 0.15 mm thick. Color 3-dimensional rapid prototyping was used to differentiate teeth, alveolus, and maxillary sinus wall. A surgical guide for the mini-implant was fabricated on the replica model. Proper positioning for mini-implants on the posterior maxilla was determined by viewing the CBCT images. The surgical guide was placed on the clinical site, and it allowed precise pilot drilling and accurate placement of the mini-implant. CBCT imaging allows remarkably lower radiation doses and thinner acquisition slices compared with medical computed tomography. Virtually reproduced replica models enable precise planning for mini-implant positions in anatomically complex sites.

14 CFR 29.1305 - Powerplant instruments.

Code of Federal Regulations, 2013 CFR

2013-01-01

... temperature indicator for each turbine engine; (12) A gas producer rotor tachometer for each turbine engine... free power turbine tachometer for each turbine engine; (16) A means, for each turbine engine, to indicate power for that engine; (17) For each turbine engine, an indicator to indicate the functioning of...

14 CFR 29.1305 - Powerplant instruments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... temperature indicator for each turbine engine; (12) A gas producer rotor tachometer for each turbine engine... free power turbine tachometer for each turbine engine; (16) A means, for each turbine engine, to indicate power for that engine; (17) For each turbine engine, an indicator to indicate the functioning of...

14 CFR 29.1305 - Powerplant instruments.

Code of Federal Regulations, 2012 CFR

2012-01-01

... temperature indicator for each turbine engine; (12) A gas producer rotor tachometer for each turbine engine... free power turbine tachometer for each turbine engine; (16) A means, for each turbine engine, to indicate power for that engine; (17) For each turbine engine, an indicator to indicate the functioning of...

14 CFR 29.1305 - Powerplant instruments.

Code of Federal Regulations, 2014 CFR

2014-01-01

... temperature indicator for each turbine engine; (12) A gas producer rotor tachometer for each turbine engine... free power turbine tachometer for each turbine engine; (16) A means, for each turbine engine, to indicate power for that engine; (17) For each turbine engine, an indicator to indicate the functioning of...

14 CFR 29.1305 - Powerplant instruments.

Code of Federal Regulations, 2011 CFR

2011-01-01

... temperature indicator for each turbine engine; (12) A gas producer rotor tachometer for each turbine engine... free power turbine tachometer for each turbine engine; (16) A means, for each turbine engine, to indicate power for that engine; (17) For each turbine engine, an indicator to indicate the functioning of...

The MiniBooNE detector

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Bartoszek, L. M.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Martin, P. S.; McGregor, G.; Metcalf, W.; Meyer, H.-O.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Nelson, R. H.; Nguyen, V. T.; Nienaber, P.; Nowak, J. A.; Ouedraogo, S.; Patterson, R. B.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Sands, W.; Schirato, R.; Schofield, G.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; Van de Water, R.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.; MiniBooNE Collaboration

2009-02-01

The MiniBooNE neutrino detector was designed and built to look for ν→ν oscillations in the (sin 2θ,Δm) parameter space region where the LSND experiment reported a signal. The MiniBooNE experiment used a beam energy and baseline that were an order of magnitude larger than those of LSND so that the backgrounds and systematic errors would be completely different. This paper provides a detailed description of the design, function, and performance of the MiniBooNE detector.

Quality Assurance Framework for Mini-Grids

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

Esterly, Sean; Baring-Gould, Ian; Booth, Samuel

To address the root challenges of providing quality power to remote consumers through financially viable mini-grids, the Global Lighting and Energy Access Partnership (Global LEAP) initiative of the Clean Energy Ministerial and the U.S. Department of Energy teamed with the National Renewable Energy Laboratory (NREL) and Power Africa to develop a Quality Assurance Framework (QAF) for isolated mini-grids. The framework addresses both alternating current (AC) and direct current (DC) mini-grids, and is applicable to renewable, fossil-fuel, and hybrid systems.

Development of a Mini-Freeze Dryer for Material-Sparing Laboratory Processing with Representative Product Temperature History.

PubMed

Obeidat, Wasfy M; Sahni, Ekneet; Kessler, William; Pikal, Michael

2018-02-01

The goal of the work described in this publication was to evaluate a new, small, material-sparing freeze dryer, denoted as the "mini-freeze dryer or mini-FD", capable of reproducing the product temperature history of larger freeze dryers, thereby facilitating scale-up. The mini-FD wall temperatures can be controlled to mimic loading procedures and dryer process characteristics of larger dryers. The mini-FD is equipped with a tunable diode laser absorption spectroscopy (TDLAS) water vapor mass flow monitor and with other advanced process analytical technology (PAT) sensors. Drying experiments were performed to demonstrate scalability to larger freeze dryers, including the determination of vial heat transfer coefficients, K v . Product temperature histories during K v runs were evaluated and compared with those obtained with a commercial laboratory-scale freeze dryer (LyoStar II) for sucrose and mannitol product formulations. When the mini-FD wall temperature was set at the LyoStar II band temperature (- 20°C) to mimic lab dryer edge vials, edge vial drying in the mini-FD possessed an average K v within 5% of those obtained during drying in the LyoStar II. When the wall temperature of the mini-FD was set equal to the central vial product temperature, edge vials behaved as center vials, possessing a K v value within 5% of those measured in the LyoStar II. During both K v runs and complete product freeze drying runs, the temperature-time profiles for the average edge vials and central vial in the mini-FD agreed well with the average edge and average central vials of the LyoStar II.

Mini Versus Standard Percutaneous Nephrolithotomy: The Impact of Sheath Size on Intrarenal Pelvic Pressure and Infectious Complications in a Porcine Model.

PubMed

Loftus, Christopher J; Hinck, Bryan; Makovey, Iryna; Sivalingam, Sri; Monga, Manoj

2018-04-01

To determine how sheath and endoscope size affect intrarenal pelvic pressures and risk of postoperative infectious complications comparing "Mini" vs "Standard" percutaneous nephrolithotomy (PCNL). Uropathogenic Escherichia coli were grown and 10 9 of them were instilled into the porcine renal pelvis through retrograde access for 1 hour. Percutaneous access utilized a 14/16F 20 cm ureteral access sheath for the Mini arm and a 30F sheath for the Standard arm. Nephroscopy was simulated utilizing either an 8/9.8F semirigid ureteroscope or 26F nephroscope for 1 hour while intrarenal pelvic pressure was continuously monitored. Blood and tissue cultures of kidney, liver, and spleen biopsies were plated and incubated and positive cultures were confirmed with polymerase chain reaction. Intrapelvic pressures were higher in the Mini group, 18.76 ± 5.82 mm Hg vs 13.56 ± 5.82 mm Hg (p < 0.0001). Time spent above 30 mm Hg was greater in the Mini arm, 117.0 seconds vs 66.1 seconds (p = 0.0452). All pigs had positive kidney tissue cultures whereas spleen cultures were positive in 100% and 60% of pigs in the Mini and Standard arms, respectively (p = 0.0253); 90% and 30% had positive liver tissue culture in the Mini and Standard arms, respectively (p = 0.0062). Blood cultures were positive in 30% of pigs in the Mini arm compared with none in the Standard arm (p = 0.0603). Mini-PCNL was associated with higher intrarenal pressures and higher risk of end organ bacterial seeding in the setting of an infected collecting system. This suggests a higher potential for infectious complications in a clinical setting.

Complete overdentures retained by mini implants: A systematic review.

PubMed

Lemos, Cleidiel Aparecido Araujo; Verri, Fellippo Ramos; Batista, Victor Eduardo de Souza; Júnior, Joel Ferreira Santiago; Mello, Caroline Cantieri; Pellizzer, Eduardo Piza

2017-02-01

The purpose of this systematic review was to evaluate the use of mini implants to retain complete overdentures in terms of survival rates of mini implants, marginal bone loss, satisfaction, and quality of life. This report followed the PRISMA Statement and PICO question. This review has been registered at PROSPERO under the number CRD42016036141. Two independent reviewers performed a comprehensive search of studies published until September 2016 and listed in the PubMed/MEDLINE, Embase, and The Cochrane Library databases. The focused question was: is the use of mini implants feasible for prosthodontic rehabilitation with complete overdentures? The 24 studies selected for review evaluated 1273 patients whose mean age was 65.93 years; these patients had received 2494 mini implants and 386 standard implants for retaining overdenture prosthesis. The mean follow-up time was 2.48 years (range: 1-7 years). There was a higher survival rate of mini implants (92.32%). More frequent failures for maxillary (31.71%) compared with mandibular arches (4.89%). The majority of studies revealed marginal bone loss values similar to those of standard implants (<1.5mm). All studies verified an increase in satisfaction and quality of life after rehabilitation treatment with mini dental implants. The present systematic review indicates that the use of mini implants for retaining overdenture prosthesis is considered an alternative treatment when standard treatment is not possible, since it presents high survival rates, acceptable marginal bone loss, and improvements in variables related to satisfaction and quality of life. Based on the results of this study, the use of a minimum 4 and 6 mini implants can be considered a satisfactory treatment option for rehabilitation of the mandibular and maxillary arches respectively with a complete overdenture. Copyright © 2016. Published by Elsevier Ltd.

Mini-Membrane Evaporator for Contingency Spacesuit Cooling

NASA Technical Reports Server (NTRS)

Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Petty, Brian; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

2015-01-01

The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only approximately 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini-ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

Mini-Membrane Evaporator for Contingency Spacesuit Cooling

NASA Technical Reports Server (NTRS)

Makinen, Janice V.; Bue, Grant C.; Campbell, Colin; Craft, Jesse; Lynch, William; Wilkes, Robert; Vogel, Matthew

2014-01-01

The next-generation Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support System (PLSS) is integrating a number of new technologies to improve reliability and functionality. One of these improvements is the development of the Auxiliary Cooling Loop (ACL) for contingency crewmember cooling. The ACL is a completely redundant, independent cooling system that consists of a small evaporative cooler--the Mini Membrane Evaporator (Mini-ME), independent pump, independent feedwater assembly and independent Liquid Cooling Garment (LCG). The Mini-ME utilizes the same hollow fiber technology featured in the full-sized AEMU PLSS cooling device, the Spacesuit Water Membrane Evaporator (SWME), but Mini-ME occupies only 25% of the volume of SWME, thereby providing only the necessary crewmember cooling in a contingency situation. The ACL provides a number of benefits when compared with the current EMU PLSS contingency cooling technology, which relies upon a Secondary Oxygen Vessel; contingency crewmember cooling can be provided for a longer period of time, more contingency situations can be accounted for, no reliance on a Secondary Oxygen Vessel (SOV) for contingency cooling--thereby allowing a reduction in SOV size and pressure, and the ACL can be recharged-allowing the AEMU PLSS to be reused, even after a contingency event. The first iteration of Mini-ME was developed and tested in-house. Mini-ME is currently packaged in AEMU PLSS 2.0, where it is being tested in environments and situations that are representative of potential future Extravehicular Activities (EVA's). The second iteration of Mini-ME, known as Mini- ME2, is currently being developed to offer more heat rejection capability. The development of this contingency evaporative cooling system will contribute to a more robust and comprehensive AEMU PLSS.

Fracture strength of orthodontic mini-implants

PubMed Central

Assad-Loss, Tatiana Feres; Kitahara-Céia, Flávia Mitiko Fernandes; Silveira, Giordani Santos; Elias, Carlos Nelson; Mucha, José Nelson

2017-01-01

ABSTRACT Objective: This study aimed at evaluating the design and dimensions of five different brands of orthodontic mini-implants, as well as their influence on torsional fracture strength. Methods: Fifty mini-implants were divided into five groups corresponding to different manufactures (DEN, RMO, CON, NEO, SIN). Twenty-five mini-implants were subjected to fracture test by torsion in the neck and the tip, through arbors attached to a Universal Mechanical Testing Machine. The other 25 mini-implants were subjected to insertion torque test into blocks of pork ribs using a torquimeter and contra-angle handpiece mounted in a surgical motor. The shape of the active tip of the mini-implants was evaluated under microscopy. The non-parametric Friedman test and Snedecor’s F in analysis of variance (ANOVA) were used to evaluate the differences between groups. Results: The fracture torque of the neck ranged from 23.45 N.cm (DEN) to 34.82 N.cm (SIN), and of the tip ranged from 9.35 N.cm (CON) to 24.36 N.cm (NEO). Insertion torque values ranged from 6.6 N.cm (RMO) to 10.2 N.cm (NEO). The characteristics that most influenced the results were outer diameter, inner diameter, the ratio between internal and external diameters, and the existence of milling in the apical region of the mini-implant. Conclusions: The fracture torques were different for both the neck and the tip of the five types evaluated. NEO and SIN mini-implants showed the highest resistance to fracture of the neck and tip. The fracture torques of both tip and neck were higher than the torque required to insert mini-implants. PMID:28746487

Roughness and wettability effect on histological and mechanical response of self-drilling orthodontic mini-implants.

PubMed

Espinar-Escalona, Eduardo; Bravo-Gonzalez, Luis-Alberto; Pegueroles, Marta; Gil, Francisco Javier

2016-06-01

Self-drilling orthodontic mini-implants can be used as temporary devices for orthodontic treatments. Our main goal was to evaluate surface characteristics, roughness and wettability, of surface modified mini-implants to increase their stability during orthodontic treatment without inducing bone fracture and tissue destruction during unscrewing. Modified mini-implants by acid etching, grit-blasting and its combination were implanted in 20 New Zealand rabbits during 10 weeks. After that, the bone-to-implant (BIC) parameter was determined and the torque during unscrewing was measured. The surface characteristics, roughness and wettability, were also measured, onto modified Ti c.p. discs. Acid-etched mini-implants (R a ≈ 1.7 μm, contact angle (CA) ≈ 66°) significantly improved the bone-to-implant parameter, 26 %, compared to as-machined mini-implants (R a ≈ 0.3 μm, CA ≈ 68°, BIC = 19 %) due to its roughness. Moreover, this surface treatment did not modify torque during unscrewing due to their statistically similar wettability (p > 0.05). Surface treatments with higher roughness and hydrophobicity (R a ≈ 4.5 μm, CA ≈ 74°) lead to a greater BIC and to a higher removal torque during unscrewing, causing bone fracture, compared to as-machined mini-implants. Based on these in vivo findings, we conclude that acid-etching surface treatment can support temporary anchoring of titanium mini-implants. This treatment represents a step forward in the direction of reducing the time prior to mini-implant loading by increasing their stability during orthodontic treatment, without inducing bone fracture and tissue destruction during unscrewing.

Method and apparatus for preventing overspeed in a gas turbine

DOEpatents

Walker, William E.

1976-01-01

A method and apparatus for preventing overspeed in a gas turbine in response to the rapid loss of applied load is disclosed. The method involves diverting gas from the inlet of the turbine, bypassing the same around the turbine and thereafter injecting the diverted gas at the turbine exit in a direction toward or opposing the flow of gas through the turbine. The injected gas is mixed with the gas exiting the turbine to thereby minimize the thermal shock upon equipment downstream of the turbine exit.

Numerical Simulations of Marine Hydrokinetic (MHK) Turbines Using the Blade Element Momentum Theory

NASA Astrophysics Data System (ADS)

Javaherchi, Teymour; Thulin, Oskar; Aliseda, Alberto

2011-11-01

Energy extraction from the available kinetic energy in tidal currents via Marine Hydrokinetic (MHK) turbines has recently attracted scientists' attention as a highly predictable source of renewable energy. The strongest tidal resources have a concentrated nature that require close turbine spacing in a farm of MHK turbines. This tight spacing, however, will lead to interaction of the downstream turbines with the turbulent wake generated by upstream turbines. This interaction can significantly reduce the power generated and possibly result in structural failure before the expected service life is completed. Development of a numerical methodology to study the turbine-wake interaction can provide a tool for optimization of turbine spacing to maximize the power generated in turbine arrays. In this work, we will present numerical simulations of the flow field in a farm of horizontal axis MHK turbines using the Blade Element Momentum Theory (BEMT). We compare the value of integral variables (i.e. efficiency, power, torque and etc.) calculated for each turbine in the farm for different arrangements with varying streamwise and lateral offsets between turbines. We find that BEMT provides accurate estimates of turbine efficiency under uniform flow conditions, but overpredicts the efficiency of downstream turbines when they are strongly affected by the wakes. Supported by DOE through the National Northwest Marine Renewable Energy Center.

MINIS: Multipurpose Interactive NASA Information System

NASA Technical Reports Server (NTRS)

1976-01-01

The Multipurpose Interactive NASA Information Systems (MINIS) was developed in response to the need for a data management system capable of operation on several different minicomputer systems. The desired system had to be capable of performing the functions of a LANDSAT photo descriptive data retrieval system while remaining general in terms of other acceptable user definable data bases. The system also had to be capable of performing data base updates and providing user-formatted output reports. The resultant MINI System provides all of these capabilities and several other features to complement the data management system. The MINI System is currently implemented on two minicomputer systems and is in the process of being installed on another minicomputer system. The MINIS is operational on four different data bases.

Turbine Design and Application, Volume 3

NASA Technical Reports Server (NTRS)

Glassman, A. J. (Editor)

1975-01-01

Turbine technology concepts for thermodynamic and fluid dynamics are presented along with velocity diagrams, losses, mechanical design, operation and performance. Designs discussed include: supersonic turbines, radial-inflow turbines, and turbine cooling.

A fish-eye view of riverine hydropower systems. Understanding the biological response to turbine passage

DOE PAGES

Pracheil, Brenda M.; DeRolph, Christopher R.; Schramm, Michael P.; ...

2016-01-01

One-way connectivity maintained by fish passing through hydropower turbines in fragmented rivers can be important to population dynamics, but can introduce a new and significant source of mortality due to turbine-associated mortality. Sources of mortality during downstream turbine passage can come from several sources including blade strike, shear forces, cavitation, or pressure decreases, and parsing the contributions of these individual forces is important for advancing and deploying turbines that minimize these impacts to fishes. We used a national hydropower database and conducted a systematic review of the literature to accomplish three goals: (1) report on the spatial distribution of turbinemore » types and generation capacities in the USA, (2) determine fish mortality rates among turbine types and fish species and (3) examine relationships between physical forces similar to those encountered during fish turbine passage and fish injury and mortality. We found that while Francis turbines generate 56% of all US hydropower and have the highest associated fish mortality of any turbine type, these turbines are proportionally understudied compared to less-common and less injury-associated Kaplan turbines, particularly in the Pacific Northwest. While juvenile salmonid species in actual or simulated Kaplan turbine conditions were the most commonly studied, the highest mortality rates were reported in percid fishes passing through Francis turbines. Also, although there are several mechanisms of turbine-associated injury, barotrauma was the most commonly studied with swim bladder rupture, exopthalmia, eye gas bubbles, and prolapsed cloaca being the most serious symptoms associated with rapid pressure decreases. Future studies should focus on understanding which species are most at-risk to turbine passage mortality and, subsequently, increasing the diversity of taxonomy and turbine types in evaluations of turbine mortality.« less

Onshore industrial wind turbine locations for the United States

USGS Publications Warehouse

Diffendorfer, Jay E.; Compton, Roger; Kramer, Louisa; Ancona, Zach; Norton, Donna

2017-01-01

This dataset provides industrial-scale onshore wind turbine locations in the United States, corresponding facility information, and turbine technical specifications. The database has wind turbine records that have been collected, digitized, locationally verified, and internally quality controlled. Turbines from the Federal Aviation Administration Digital Obstacles File, through product release date July 22, 2013, were used as the primary source of turbine data points. The dataset was subsequently revised and reposted as described in the revision histories for the report. Verification of the turbine positions was done by visual interpretation using high-resolution aerial imagery in Environmental Systems Research Institute (Esri) ArcGIS Desktop. Turbines without Federal Aviation Administration Obstacles Repository System numbers were visually identified and point locations were added to the collection. We estimated a locational error of plus or minus 10 meters for turbine locations. Wind farm facility names were identified from publicly available facility datasets. Facility names were then used in a Web search of additional industry publications and press releases to attribute additional turbine information (such as manufacturer, model, and technical specifications of wind turbines). Wind farm facility location data from various wind and energy industry sources were used to search for and digitize turbines not in existing databases. Technical specifications for turbines were assigned based on the wind turbine make and model as described in literature, specifications listed in the Federal Aviation Administration Digital Obstacles File, and information on the turbine manufacturer’s Web site. Some facility and turbine information on make and model did not exist or was difficult to obtain. Thus, uncertainty may exist for certain turbine specifications. That uncertainty was rated and a confidence was recorded for both location and attribution data quality.

A fish-eye view of riverine hydropower systems. Understanding the biological response to turbine passage

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

Pracheil, Brenda M.; DeRolph, Christopher R.; Schramm, Michael P.

One-way connectivity maintained by fish passing through hydropower turbines in fragmented rivers can be important to population dynamics, but can introduce a new and significant source of mortality due to turbine-associated mortality. Sources of mortality during downstream turbine passage can come from several sources including blade strike, shear forces, cavitation, or pressure decreases, and parsing the contributions of these individual forces is important for advancing and deploying turbines that minimize these impacts to fishes. We used a national hydropower database and conducted a systematic review of the literature to accomplish three goals: (1) report on the spatial distribution of turbinemore » types and generation capacities in the USA, (2) determine fish mortality rates among turbine types and fish species and (3) examine relationships between physical forces similar to those encountered during fish turbine passage and fish injury and mortality. We found that while Francis turbines generate 56% of all US hydropower and have the highest associated fish mortality of any turbine type, these turbines are proportionally understudied compared to less-common and less injury-associated Kaplan turbines, particularly in the Pacific Northwest. While juvenile salmonid species in actual or simulated Kaplan turbine conditions were the most commonly studied, the highest mortality rates were reported in percid fishes passing through Francis turbines. Also, although there are several mechanisms of turbine-associated injury, barotrauma was the most commonly studied with swim bladder rupture, exopthalmia, eye gas bubbles, and prolapsed cloaca being the most serious symptoms associated with rapid pressure decreases. Future studies should focus on understanding which species are most at-risk to turbine passage mortality and, subsequently, increasing the diversity of taxonomy and turbine types in evaluations of turbine mortality.« less

Tail Shape Design of Boat Wind Turbines

NASA Astrophysics Data System (ADS)

Singamsitty, Venkatesh

Wind energy is a standout among the most generally utilized sustainable power source assets. A great deal of research and improvements have been happening in the wind energy field. Wind turbines are mechanical devices that convert kinetic energy into electrical power. Boat wind turbines are for the small-scale generation of electric power. In order to catch wind energy effectively, boat wind turbines need to face wind direction. Tails are used in boat wind turbines to alter the wind turbine direction and receive the variation of the incoming direction of wind. Tails are used to change the performance of boat wind turbines in an effective way. They are required to generate a quick and steady response as per change in wind direction. Tails can have various shapes, and their effects on boat wind turbines are different. However, the effects of tail shapes on the performance of boat wind turbines are not thoroughly studied yet. In this thesis, five tail shapes were studied. Their effects on boat wind turbines were investigated. The power extracted by the turbines from the air and the force acting on the boat wind turbine tail were analyzed. The results of this thesis provide a guideline of tail shape design for boat wind turbines.

Next Generation Fast Neutron Detector for Space Exploration (Mini-FND)

NASA Astrophysics Data System (ADS)

Hassler, D. M.; Ehresmann, B.

2018-02-01

SwRI has developed a miniature Fast Neutron Detector (mini-FND), for use in the Deep Space Gateway, to characterize the neutron albedo radiation. Mini-FND will provide coverage of the biologically relevant neutrons at energies of 500 keV and greater.

Controller Evaluation of Initial Data Link Air Traffic Control Services, Mini Study 1, Volume 2

DOT National Transportation Integrated Search

1988-09-01

This report details the results of Mini Study 1. This mini study was conducted : at the Federal Aviation Administration (FAA) Technical Center utilizing the Data : Link testbed. Initial Data Link air traffic control services were evaluated : under pa...

A regulatory toolbox of MiniPromoters to drive selective expression in the brain.

PubMed

Portales-Casamar, Elodie; Swanson, Douglas J; Liu, Li; de Leeuw, Charles N; Banks, Kathleen G; Ho Sui, Shannan J; Fulton, Debra L; Ali, Johar; Amirabbasi, Mahsa; Arenillas, David J; Babyak, Nazar; Black, Sonia F; Bonaguro, Russell J; Brauer, Erich; Candido, Tara R; Castellarin, Mauro; Chen, Jing; Chen, Ying; Cheng, Jason C Y; Chopra, Vik; Docking, T Roderick; Dreolini, Lisa; D'Souza, Cletus A; Flynn, Erin K; Glenn, Randy; Hatakka, Kristi; Hearty, Taryn G; Imanian, Behzad; Jiang, Steven; Khorasan-zadeh, Shadi; Komljenovic, Ivana; Laprise, Stéphanie; Liao, Nancy Y; Lim, Jonathan S; Lithwick, Stuart; Liu, Flora; Liu, Jun; Lu, Meifen; McConechy, Melissa; McLeod, Andrea J; Milisavljevic, Marko; Mis, Jacek; O'Connor, Katie; Palma, Betty; Palmquist, Diana L; Schmouth, Jean-François; Swanson, Magdalena I; Tam, Bonny; Ticoll, Amy; Turner, Jenna L; Varhol, Richard; Vermeulen, Jenny; Watkins, Russell F; Wilson, Gary; Wong, Bibiana K Y; Wong, Siaw H; Wong, Tony Y T; Yang, George S; Ypsilanti, Athena R; Jones, Steven J M; Holt, Robert A; Goldowitz, Daniel; Wasserman, Wyeth W; Simpson, Elizabeth M

2010-09-21

The Pleiades Promoter Project integrates genomewide bioinformatics with large-scale knockin mouse production and histological examination of expression patterns to develop MiniPromoters and related tools designed to study and treat the brain by directed gene expression. Genes with brain expression patterns of interest are subjected to bioinformatic analysis to delineate candidate regulatory regions, which are then incorporated into a panel of compact human MiniPromoters to drive expression to brain regions and cell types of interest. Using single-copy, homologous-recombination "knockins" in embryonic stem cells, each MiniPromoter reporter is integrated immediately 5' of the Hprt locus in the mouse genome. MiniPromoter expression profiles are characterized in differentiation assays of the transgenic cells or in mouse brains following transgenic mouse production. Histological examination of adult brains, eyes, and spinal cords for reporter gene activity is coupled to costaining with cell-type-specific markers to define expression. The publicly available Pleiades MiniPromoter Project is a key resource to facilitate research on brain development and therapies.

NEW CLASS OF VERY HIGH ENERGY {gamma}-RAY EMITTERS: RADIO-DARK MINI SHELLS SURROUNDING ACTIVE GALACTIC NUCLEUS JETS

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

Kino, Motoki; Ito, Hirotaka; Kawakatu, Nozomu

We explore non-thermal emission from a shocked interstellar medium, which is identified as an expanding shell, driven by a relativistic jet in active galactic nuclei (AGNs). In this work, we particularly focus on parsec-scale size mini shells surrounding mini radio lobes. From the radio to X-ray band, the mini radio lobe emission dominates the faint emission from the mini shell. On the other hand, we find that inverse-Compton (IC) emission from the shell can overwhelm the associated lobe emission at the very high energy (VHE; E > 100 GeV) {gamma}-ray range, because energy densities of synchrotron photons from the lobemore » and/or soft photons from the AGN nucleus are large and IC scattering works effectively. The predicted IC emission from nearby mini shells can be detected with the Cherenkov Telescope Array and they are potentially a new class of VHE {gamma}-ray emitters.« less

Impact of a Ground Network of Miniaturized Laser Heterodyne Radiometers (mini-LHRs) on Global Carbon Flux Estimates

NASA Astrophysics Data System (ADS)

DiGregorio, A.; Wilson, E. L.; Palmer, P. I.; Mao, J.; Feng, L.

2017-12-01

We present the simulated impact of a small (50 instrument) ground network of NASA Goddard Space Flight Center's miniaturized laser heterodyne radiometer (mini-LHR), a small, low cost ( 50k), portable, and high precision CH4 and CO2 measuring instrument. Partnered with AERONET as a non-intrusive accessory, the mini-LHR is able to leverage the 500+ instrument AERONET network for rapid network deployment and testing, and simultaneously retrieve co-located aerosol data, an important input for sattelite measurements. This observing systems simulation experiment (OSSE) uses the 3-D GEOS-Chem chemistry transport model and 50 strategically selected sites to model flux estimate uncertainty reduction of both TCCON and mini-LHR instruments. We found that 50 mini-LHR sites are capable of improving global uncertainty by up to 70%, with local improvements in the Southern Hemisphere reaching to 90%. Our studies show that addition of the mini-LHR to current ground networks will play a major role in reduction of global carbon flux uncertainty.

Two-phase turbine engines. [using gas-liquid mixture accelerated in nozzles

NASA Technical Reports Server (NTRS)

Elliott, D. G.; Hays, L. G.

1976-01-01

A description is given of a two-phase turbine which utilizes a uniform mixture of gas and liquid accelerated in nozzles of the types reported by Elliott and Weinberg (1968). The mixture acts directly on an axial flow or tangential impulse turbine or is separated into gas and liquid streams which operate separately on a gas turbine and a hydraulic turbine. The basic two-phase cycles are examined, taking into account working fluids, aspects of nozzle expansion, details of turbine cycle operation, and the effect of mixture ratio variation. Attention is also given to two-phase nozzle efficiency, two-phase turbine operating characteristics and efficiencies, separator turbines, and impulse turbine experiments.

Experimental testing of axial induction based control strategies for wake control and wind farm optimization

NASA Astrophysics Data System (ADS)

Bartl, J.; Sætran, L.

2016-09-01

In state-of-the-art wind farms each turbine is controlled individually aiming for optimum turbine power not considering wake effects on downstream turbines. Wind farm control concepts aim for optimizing the overall power output of the farm taking wake interactions between the individual turbines into account. This experimental wind tunnel study investigates axial induction based control concepts. It is examined how the total array efficiency of two in-line model turbines is affected when the upstream turbine's tip speed ratio (λcontrol) or blade pitch angle (β-control) is modified. The focus is particularly directed on how the wake flow behind the upstream rotor is affected when its axial induction is reduced in order to leave more kinetic energy in the wake to be recovered by a downstream turbine. It is shown that the radial distribution of kinetic energy in the wake area can be controlled by modifying the upstream turbine's tip speed ratio. By pitching out the upstream turbine's blades, however, the available kinetic energy in the wake is increased at an equal rate over the entire blade span. Furthermore, the total array efficiency of the two turbine setup is mapped depending on the upstream turbines tip speed ratio and pitch angle. For a small turbine separation distance of x/D=3 the downstream turbine is able to recover the major part of the power lost on the upstream turbine. However, no significant increase in the two-turbine array efficiency is achieved by altering the upstream turbine's operation point away from its optimum.

Cost/benefit analysis of advanced materials technologies for future aircraft turbine engines

NASA Technical Reports Server (NTRS)

Bisset, J. W.

1976-01-01

The cost/benefits of advance commercial gas turbine materials are described. Development costs, estimated payoffs and probabilities of success are discussed. The materials technologies investigated are: (1) single crystal turbine blades, (2) high strength hot isostatic pressed turbine disk, (3) advanced oxide dispersion strengthened burner liner, (4) bore entry cooled hot isostatic pressed turbine disk, (5) turbine blade tip - outer airseal system, and (6) advance turbine blade alloys.

Seed Embryo Development Is Regulated via an AN3-MINI3 Gene Cascade

PubMed Central

Meng, Lai-Sheng; Wang, Yi-Bo; Loake, Gary J.; Jiang, Ji-Hong

2016-01-01

In agriculture, seed mass is one of the most important components related to seed yield. MINISEED3 (MINI3) which encodes the transcriptional activator WRKY10, is thought to be a pivotal regulator of seed mass. In Arabidopsis SHORT HYPOCOTYL UNDER BLUE1 (SHB1) associates with the promoter of MINI3, regulating embryo cell proliferation (both cell division and elongation), which, in turn, modulates seed mass. Furthermore, the recruitment of SHB1 via MINI3 to both its cognate promoter and that of IKU2 implies a two-step amplification for countering the low expression level of IKU2, which is thought to function as a molecular switch for seed cavity enlargement. However, it is largely unknown how embryo cell proliferation, which encompasses both cell division and elongation, is regulated by SHB1 and MINI3 function. Here, we show that a loss of function mutation within the transcriptional coactivator ANGUSTIFOLIA3 (AN3), increases seed mass. Further, AN3 associates with the MINI3 promoter in vivo. Genetic evidence indicates that the absence of MINI3 function suppresses the decrease of cell number observed in an3-4 mutants by regulating cell division and in turn inhibits increased cell size of the an3-4 line by controlling cell elongation. Thus, seed embryo development is modulated via an AN3-MINI3 gene cascade. This regulatory model provides a deeper understanding of seed mass regulation, which may in turn lead to increased crop yields. PMID:27857719

The mini-cog: a cognitive 'vital signs' measure for dementia screening in multi-lingual elderly.

PubMed

Borson, S; Scanlan, J; Brush, M; Vitaliano, P; Dokmak, A

2000-11-01

The Mini-Cog, a composite of three-item recall and clock drawing, was developed as a brief test for discriminating demented from non-demented persons in a community sample of culturally, linguistically, and educationally heterogeneous older adults. All 129 who met criteria for probable dementia based on informant interviews and 120 with no history of cognitive decline were included; 124 were non-English speakers. Sensitivity, specificity, and diagnostic value of the Mini-Cog were compared with those of the Mini-Mental State Exam (MMSE) and Cognitive Abilities Screening Instrument (CASI). The Mini-Cog had the highest sensitivity (99%) and correctly classified the greatest percentage (96%) of subjects. Moreover, its diagnostic value was not influenced by education or language, while that of the CASI was adversely influenced by low education, and both education and language compromised the diagnostic value of the MMSE. Administration time for the Mini-Cog was 3 minutes vs 7 minutes for the MMSE. The Mini-Cog required minimal language interpretation and training to administer, and no test forms of scoring modifications were needed to compensate for the extensive linguistic and educational heterogeneity of the sample. Validation in clinical and population-based samples is warranted, as its brevity and ease of administration suggest that the Mini-Cog might be readily incorporated into general practice and senior care settings as a routine 'cognitive vital signs' measure. Copyright 2000 John Wiley & Sons, Ltd.

Fully customized placement of orthodontic miniplates: a novel clinical technique

PubMed Central

2014-01-01

Introduction The initial stability and survival rate of orthodontic mini-implants are highly dependent on the amount of cortical bone at their insertion site. In areas with limited bone availability, mini-plates are preferred to provide effective skeletal anchorage. The purpose of this paper was to present a new clinical technique for the insertion of mini-plates. Methods In order to apply this new technique, a cone-beam image of the insertion area is required. A software (Galaxy Sirona, Bensheim, Germany) is used to construct a three-dimensional image of the scanned area and to virtually determine the exact location of the mini-plate as well as the position of the fixation screws. A stereolithographic model (STL) is then created by means of a three-dimensional scanner. Prior to its surgical insertion, the bone plate is adapted to the stereo-lithographic model. Finally, a custom transfer jig is fabricated in order to assist with accurate placement of the mini-plate intra-operatively. Results The presented technique minimizes intra-operative decision making, because the final position of the bone plate is determined pre-surgically. This significantly reduces the duration of the surgical procedure and improves its outcome. Conclusions A novel method for surgical placement of orthodontic mini-plates is presented. The technique facilitates accurate adaptation of mini-plates and insertion of retaining surgical screws; thereby enabling clinicians to more confidently increase the use of bone plates, especially in anatomical areas where the success of non-osseointegrated mini-screws is less favorable. PMID:24886597

Water turbine technology for small power stations

NASA Astrophysics Data System (ADS)

Salovaara, T.

1980-02-01

The paper examines hydro-power stations and the efficiency and costs of using water turbines to run them. Attention is given to different turbine types emphasizing the use of Kaplan-turbines and runners. Hydraulic characteristics and mechanical properties of low head turbines and small turbines, constructed of fully fabricated steel plate structures, are presented.

40 CFR 63.6095 - When do I have to comply with this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... stationary combustion turbine or a diffusion flame oil-fired stationary combustion turbine as defined by this... combustion turbine which is a lean premix oil-fired stationary combustion turbine or a diffusion flame oil... stationary combustion turbine or diffusion flame gas-fired stationary combustion turbine as defined by this...

40 CFR 63.6095 - When do I have to comply with this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... stationary combustion turbine or a diffusion flame oil-fired stationary combustion turbine as defined by this... combustion turbine which is a lean premix oil-fired stationary combustion turbine or a diffusion flame oil... stationary combustion turbine or diffusion flame gas-fired stationary combustion turbine as defined by this...

40 CFR 63.6095 - When do I have to comply with this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... stationary combustion turbine or a diffusion flame oil-fired stationary combustion turbine as defined by this... combustion turbine which is a lean premix oil-fired stationary combustion turbine or a diffusion flame oil... stationary combustion turbine or diffusion flame gas-fired stationary combustion turbine as defined by this...

40 CFR 63.6095 - When do I have to comply with this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... stationary combustion turbine or a diffusion flame oil-fired stationary combustion turbine as defined by this... combustion turbine which is a lean premix oil-fired stationary combustion turbine or a diffusion flame oil... stationary combustion turbine or diffusion flame gas-fired stationary combustion turbine as defined by this...

40 CFR 63.6095 - When do I have to comply with this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... stationary combustion turbine or a diffusion flame oil-fired stationary combustion turbine as defined by this... combustion turbine which is a lean premix oil-fired stationary combustion turbine or a diffusion flame oil... stationary combustion turbine or diffusion flame gas-fired stationary combustion turbine as defined by this...

Cold flow testing of the Space Shuttle Main Engine alternate turbopump development high pressure fuel turbine model

NASA Technical Reports Server (NTRS)

Gaddis, Stephen W.; Hudson, Susan T.; Johnson, P. D.

1992-01-01

NASA's Marshall Space Flight Center has established a cold airflow turbine test program to experimentally determine the performance of liquid rocket engine turbopump drive turbines. Testing of the SSME alternate turbopump development (ATD) fuel turbine was conducted for back-to-back comparisons with the baseline SSME fuel turbine results obtained in the first quarter of 1991. Turbine performance, Reynolds number effects, and turbine diagnostics, such as stage reactions and exit swirl angles, were investigated at the turbine design point and at off-design conditions. The test data showed that the ATD fuel turbine test article was approximately 1.4 percent higher in efficiency and flowed 5.3 percent more than the baseline fuel turbine test article. This paper describes the method and results used to validate the ATD fuel turbine aerodynamic design. The results are being used to determine the ATD high pressure fuel turbopump (HPFTP) turbine performance over its operating range, anchor the SSME ATD steady-state performance model, and validate various prediction and design analyses.

The methodology of the gas turbine efficiency calculation

NASA Astrophysics Data System (ADS)

Kotowicz, Janusz; Job, Marcin; Brzęczek, Mateusz; Nawrat, Krzysztof; Mędrych, Janusz

2016-12-01

In the paper a calculation methodology of isentropic efficiency of a compressor and turbine in a gas turbine installation on the basis of polytropic efficiency characteristics is presented. A gas turbine model is developed into software for power plant simulation. There are shown the calculation algorithms based on iterative model for isentropic efficiency of the compressor and for isentropic efficiency of the turbine based on the turbine inlet temperature. The isentropic efficiency characteristics of the compressor and the turbine are developed by means of the above mentioned algorithms. The gas turbine development for the high compressor ratios was the main driving force for this analysis. The obtained gas turbine electric efficiency characteristics show that an increase of pressure ratio above 50 is not justified due to the slight increase in the efficiency with a significant increase of turbine inlet combustor outlet and temperature.

Controller Evaluation of Initial Data Link Air Traffic Control Services: Mini Study 2 Volume II

DOT National Transportation Integrated Search

1989-03-01

This report details the results of Mini Study 2. This Mini Study was conducted at the Federal Aviation Administration (FAA) Technical Center utilizing the Data Link test bed. Initial Data Link air traffic control services were evaluated under part ta...

Mini-Lectures: A Taster to Engage the Audience for the Main Event

ERIC Educational Resources Information Center

Ingram, Matthew J.; Crane, Simeon; Mokree, Alan; Curdy, Marion E.; Patel, Bhavik A.

2017-01-01

This article explores the use of pre-recorded video mini-lectures to support and enhance traditional face-to-face lectures for undergraduate students. Mini-lectures guide students through key concepts so that they can understand and assimilate key content before attending lectures.

Controller Evaluation of Initial Data Link Air Traffic Control Services: Mini Study 2 Volume I

DOT National Transportation Integrated Search

1989-03-01

This report details the results of Mini Study 2. This Mini Study was conducted at the Federal Aviation Administration (FAA) Technical Center utilizing the Data Link test bed. Initial Data Link air traffic control services were evaluated under part ta...

Controller Evaluation of Initial Data Link Air Traffic Control Services, Mini Study 1, Volume 1

DOT National Transportation Integrated Search

1988-09-01

This report details the results of Mini Study 1. This mini study was conducted : at the Federal Aviation (FAA) Technical Center utilizing the Data Link testbed. : Initial Data Link air traffic control services were under part task simulation : condit...

Sean Esterly | NREL

Science.gov Websites

, micro and mini-grid policies and regulations, and international clean energy policy analysis. He has technologies, such as micro- and mini-grids. Strategic energy planning, focusing on both renewable and energy Considerations and Good Practices, NREL Technical Report (2015) Quality Assurance Framework for Mini-Grids, NREL

Turbine Inlet Air Cooling for Industrial and Aero-derivative Gas Turbine in Malaysia Climate

NASA Astrophysics Data System (ADS)

Nordin, A.; Salim, D. A.; Othoman, M. A.; Kamal, S. N. Omar; Tam, Danny; Yusof, M. KY

2017-12-01

The performance of a gas turbine is dependent on the ambient temperature. A higher temperature results in a reduction of the gas turbine’s power output and an increase in heat rate. The warm and humid climate in Malaysia with its high ambient air temperature has an adverse effect on the performance of gas turbine generators. In this paper, the expected effect of turbine inlet air cooling technology on the annual performance of an aero-derivative gas turbine (GE LM6000PD) is compared against that of an industrial gas turbine (GEFr6B.03) using GT Pro software. This study investigated the annual net energy output and the annual net electrical efficiency of a plant with and without turbine inlet air cooling technology. The results show that the aero-derivative gas turbine responds more favorably to turbine inlet air cooling technology, thereby yielding higher annual net energy output and higher net electrical efficiency when compared to the industrial gas turbine.

Comparison of Water Turbine Characteristics using Different Blades in Darrieus Water Turbines used for Tidal Current Generations

NASA Astrophysics Data System (ADS)

Shiono, Mitsuhiro; Suzuki, Katsuyuki; Kiho, Seiji

The use of renewable energies has been focused on for preserving environments and coping with the shortage of future energy supplies. In oceans, a tide reverses its current direction every six hours, and the current velocity changes into a sine wave after a period of time. Tidal current generation uses a generator to produce energy, changing the kinetic energy of current into a turning force by setting a water turbine in the tidal current. Therefore, it is considered to be very advantageous to use a water turbine that can always revolve in a fixed direction without any influence from tidal current directions. Water turbines with these characteristics are known as Darrieus water turbines. The Darrieus water turbines were modified for water from turbines originally developed for windmills. Darrieus water turbines have a difficulty in starting, but these days Darrieus water turbines have been developed with spiral blades, which make it easy to get the turbines started. However, there are very few reports regarding Darrieus water turbines with spiral blades, and therefore their characteristics are unknown. From the above points of view, this study devises and investigates spiral blade-Darrieus water turbines to clarify their characteristics through hydrographic experiments, and at the same time, it compares the characteristics of spiral-blade Darrieus water turbines with those of straight-blade ones.

30. VICTOR WATER TURBINE, STILWELLBIERCE CO., DAYTON, OHIO. SIMILAR TURBINE ...

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

30. VICTOR WATER TURBINE, STILWELL-BIERCE CO., DAYTON, OHIO. SIMILAR TURBINE TO LEFT (DOUBLE TURBINE SYSTEM), PHOTO TAKEN FROM PENSTOCK. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

Progress in the utilization of an oxide-dispersion-strengthened alloy for small engine turbine blades

NASA Technical Reports Server (NTRS)

Beatty, T. G.; Millan, P. P.

1984-01-01

The conventional means of improving gas turbine engine performance typically involves increasing the turbine inlet temperature; however, at these higher operational temperatures the high pressure turbine blades require air-cooling to maintain durability. Air-cooling imposes design, material, and economic constraints not only on the turbine blades but also on engine performance. The use of uncooled turbine blades at increased operating temperatures can offer significantly improved performance in small gas turbine engines. A program to demonstrate uncooled MA6000 high pressure turbine blades in a GTEC TFE731 turbofan engine is being conducted. The project goals include demonstration of the advantages of using uncooled MA6000 turbine blades as compared with cast directionally solidified MAR-M 247 blades.

The effects of solarization on the performance of a gas turbine

NASA Astrophysics Data System (ADS)

Homann, Christiaan; van der Spuy, Johan; von Backström, Theodor

2016-05-01

Various hybrid solar gas turbine configurations exist. The Stellenbosch University Solar Power Thermodynamic (SUNSPOT) cycle consists of a heliostat field, solar receiver, primary Brayton gas turbine cycle, thermal storage and secondary Rankine steam cycle. This study investigates the effect of the solarization of a gas turbine on its performance and details the integration of a gas turbine into a solar power plant. A Rover 1S60 gas turbine was modelled in Flownex, a thermal-fluid system simulation and design code, and validated against a one-dimensional thermodynamic model at design input conditions. The performance map of a newly designed centrifugal compressor was created and implemented in Flownex. The effect of the improved compressor on the performance of the gas turbine was evident. The gas turbine cycle was expanded to incorporate different components of a CSP plant, such as a solar receiver and heliostat field. The solarized gas turbine model simulates the gas turbine performance when subjected to a typical variation in solar resource. Site conditions at the Helio100 solar field were investigated and the possibility of integrating a gas turbine within this system evaluated. Heat addition due to solar irradiation resulted in a decreased fuel consumption rate. The influence of the additional pressure drop over the solar receiver was evident as it leads to decreased net power output. The new compressor increased the overall performance of the gas turbine and compensated for pressure losses incurred by the addition of solar components. The simulated integration of the solarized gas turbine at Helio100 showed potential, although the solar irradiation is too little to run the gas turbine on solar heat alone. The simulation evaluates the feasibility of solarizing a gas turbine and predicts plant performance for such a turbine cycle.

A wind tunnel study on the effects of complex topography on wind turbine performance

NASA Astrophysics Data System (ADS)

Howard, Kevin; Hu, Stephen; Chamorro, Leonardo; Guala, Michele

2012-11-01

A set of wind tunnel experiments were conducted to study the response of a wind turbine under flow conditions typically observed at the wind farm scale, in complex terrain. A scale model wind turbine was placed in a fully developed turbulent boundary layer flow obtained in the SAFL Wind Tunnel. Experiments focused on the performance of a turbine model, under the effects induced by a second upwind turbine or a by three-dimensional, sinusoidal hill, peaking at the turbine hub height. High frequency measurements of fluctuating streamwise and wall normal velocities were obtained with a X-wire anemometer simultaneously with the rotor angular velocity and the turbine(s) voltage output. Velocity measurements in the wake of the first turbine and of the hill were used to determine the inflow conditions for the downwind test turbine. Turbine performance was inferred by the mean and fluctuating voltage statistics. Specific experiments were devoted to relate the mean voltage to the mean hub velocity, and the fluctuating voltage to the unsteadiness in the rotor kinematics induced by the perturbed (hill or turbine) or unperturbed (boundary layer) large scales of the incoming turbulent flow. Results show that the voltage signal can be used to assess turbine performance in complex flows.

Predictors of Rater Bias in the Assessment of Social-Emotional Competence

ERIC Educational Resources Information Center

Shapiro, Valerie B.; Kim, B. K. Elizabeth; Accomazzo, Sarah; Roscoe, Joe N.

2016-01-01

"The Devereux Student Strengths Assessment Mini" (DESSA-Mini) (LeBuffe, Shapiro, & Naglieri, 2014) efficiently monitors the growth of Social-Emotional Competence (SEC) in the routine implementation of Social Emotional Learning programs. The DESSA-Mini is used to assess approximately half a million children around the world. Since…

Mini-Rocket User Guide

DTIC Science & Technology

2007-08-01

26 ISTC Simulation Comparisons ............................................................................... 29 STARS...Range Comparison Figure 8. ISTC Simulntioiz Comparisons 29 Mini-Rocket User Guide REAL-WORLD COMPARISON In particular, note the very high angle-of...not directly model the missile rigid body dynamics. The ISTC subsequently used Mini-Rocket as a driver to stimulate other models and as a risk

Teaching Economics in the Mini-Economy.

ERIC Educational Resources Information Center

Indiana State Dept. of Education, Indianapolis.

This booklet produced by the State of Indiana introduces elementary teachers to economic concepts appropriate to the elementary curriculum and explains how to use mini-economy activities to teach these concepts. Chapter 1 describes how the mini-economy works, while chapter 2 introduces basic economic vocabulary and discusses market economy. Ideas…

Partners | Integrated Energy Solutions | NREL

Science.gov Websites

Develops Off-Grid Energy Access through Quality Assurance Framework for Mini-Grids NREL has teamed with the Africa to develop a Quality Assurance Framework for isolated mini-grids. NREL Enhances Energy Resiliency Partnership Develops Off-Grid Energy Access through Quality Assurance Framework for Mini-Grids NREL has teamed

NREL Partnership Develops Off-Grid Energy Access through Quality Assurance

Science.gov Websites

Framework for Mini-Grids | Integrated Energy Solutions | NREL Partnership Develops Off-Grid Energy Access through Quality Assurance Framework for Mini-Grids NREL Partnership Develops Off-Grid Energy Access through Quality Assurance Framework for Mini-Grids NREL has teamed with the Global Lighting

NREL: International Activities - Energy Access

Science.gov Websites

experience with off-grid solutions to support mini and microgrid projects, policies, and programs that are prohibitively expensive. Investment interest in mini and microgrids for energy access has been growing among Quality Assurance Framework (QAF) for mini-grids was developed to address the root challenges to providing

Mini-clusters

NASA Technical Reports Server (NTRS)

Chinellato, J. A.; Dobrigkeit, C.; Bellandifilho, J.; Lattes, C. M. G.; Menon, M. J.; Navia, C. E.; Pamilaju, A.; Sawayanagi, K.; Shibuya, E. H.; Turtelli, A., Jr.

1985-01-01

Experimental results of mini-clusters observed in Chacaltaya emulsion chamber no.19 are summarized. The study was made on 54 single core shower upper and 91 shower clusters of E(gamma) 10 TeV from 30 families which are visible energy greater than 80 TeV and penetrate through both upper and lower detectors of the two-story chamber. The association of hadrons in mini-cluster is made clear from their penetrative nature and microscopic observation of shower continuation in lower chamber. Small P sub t (gamma) of hadrons in mini-clusters remained in puzzle.

Time domain modal identification/estimation of the mini-mast testbed

NASA Technical Reports Server (NTRS)

Roemer, Michael J.; Mook, D. Joseph

1991-01-01

The Mini-Mast is a 20 meter long 3-dimensional, deployable/retractable truss structure designed to imitate future trusses in space. Presented here are results from a robust (with respect to measurement noise sensitivity), time domain, modal identification technique for identifying the modal properties of the Mini-Mast structure even in the face of noisy environments. Three testing/analysis procedures are considered: sinusoidal excitation near resonant frequencies of the Mini-Mast, frequency response function averaging of several modal tests, and random input excitation with a free response period.

Systemic levels of metallic ions released from orthodontic mini-implants.

PubMed

de Morais, Liliane Siqueira; Serra, Glaucio Guimarães; Albuquerque Palermo, Elisabete Fernandes; Andrade, Leonardo Rodrigues; Müller, Carlos Alberto; Meyers, Marc André; Elias, Carlos Nelson

2009-04-01

Orthodontic mini-implants are a potential source of metallic ions to the human body because of the corrosion of titanium (Ti) alloy in body fluids. The purpose of this study was to gauge the concentration of Ti, aluminum (Al), and vanadium (V), as a function of time, in the kidneys, livers, and lungs of rabbits that had Ti-6Al-4V alloy orthodontic mini-implants placed in their tibia. Twenty-three New Zealand rabbits were randomly divided into 4 groups: control, 1 week, 4 weeks, and 12 weeks. Four orthodontic mini-implants were placed in the left proximal tibia of 18 rabbits. Five control rabbits had no orthodontic mini-implants. After 1, 4, and 12 weeks, the rabbits were killed, and the selected tissues were extracted and prepared for analysis by graphite furnace atomic absorption spectrophotometry. Low amounts of Ti, Al, and V were detectable in the 1-week, 4-weeks, and 12-weeks groups, confirming that release of these metals from the mini-implants occurs, with diffusion and accumulation in remote organs. Despite the tendency of ion release when using the Ti alloy as orthodontic mini-implants, the amounts of metals detected were significantly below the average intake of these elements through food and drink and did not reach toxic concentrations.

Accuracy of mini peak flow meters in indicating changes in lung function in children with asthma.

PubMed Central

Sly, P. D.; Cahill, P.; Willet, K.; Burton, P.

1994-01-01

OBJECTIVE--To assess whether mini flow meters used to measure peak expiratory flow can track changes in lung function and indicate clinically important changes. DESIGN--Comparison of measurements with a spirometer and different brands of mini flow meter; the meters were allocated to subjects haphazardly. SUBJECTS--12 boys with asthma aged 11 to 17 attending boarding school. MAIN OUTCOME MEASURES--Peak expiratory flow measured twice daily for three months with a spirometer and at least one of four brands of mini flow meter. RESULTS--The relation between changes in lung function measured with the spirometer and those measured with the mini flow meters was generally poor. In all, 26 episodes (range 1-3 in an individual child) of clinically important deterioration in lung function were detected from the records obtained with the spirometer. One mini flow meter detected six of 19 episodes, one detected six of 15, one detected six of 18, and one detected three of 21. CONCLUSIONS--Not only are the absolute values of peak expiratory flow obtained with mini flow meters inaccurate but the clinical message may also be incorrect. These findings do not imply that home monitoring of peak expiratory flow has no place in the management of childhood asthma but that the values obtained should be interpreted cautiously. PMID:8148680

Direct typing of Canine parvovirus (CPV) from infected dog faeces by rapid mini sequencing technique.

PubMed

V, Pavana Jyothi; S, Akila; Selvan, Malini K; Naidu, Hariprasad; Raghunathan, Shwethaa; Kota, Sathish; Sundaram, R C Raja; Rana, Samir Kumar; Raj, G Dhinakar; Srinivasan, V A; Mohana Subramanian, B

2016-12-01

Canine parvovirus (CPV) is a non-enveloped single stranded DNA virus with an icosahedral capsid. Mini-sequencing based CPV typing was developed earlier to detect and differentiate all the CPV types and FPV in a single reaction. This technique was further evaluated in the present study by performing the mini-sequencing directly from fecal samples which avoided tedious virus isolation steps by cell culture system. Fecal swab samples were collected from 84 dogs with enteritis symptoms, suggestive of parvoviral infection from different locations across India. Seventy six of these samples were positive by PCR; the subsequent mini-sequencing reaction typed 74 of them as type 2a virus, and 2 samples as type 2b. Additionally, 25 of the positive samples were typed by cycle sequencing of PCR products. Direct CPV typing from fecal samples using mini-sequencing showed 100% correlation with CPV typing by cycle sequencing. Moreover, CPV typing was achieved by mini-sequencing even with faintly positive PCR amplicons which was not possible by cycle sequencing. Therefore, the mini-sequencing technique is recommended for regular epidemiological follow up of CPV types, since the technique is rapid, highly sensitive and high capacity method for CPV typing. Copyright © 2016. Published by Elsevier B.V.

Spurious RF signals emitted by mini-UAVs

NASA Astrophysics Data System (ADS)

Schleijpen, Ric (H. M. A.); Voogt, Vincent; Zwamborn, Peter; van den Oever, Jaap

2016-10-01

This paper presents experimental work on the detection of spurious RF emissions of mini Unmanned Aerial Vehicles (mini-UAV). Many recent events have shown that mini-UAVs can be considered as a potential threat for civil security. For this reason the detection of mini-UAVs has become of interest to the sensor community. The detection, classification and identification chain can take advantage of different sensor technologies. Apart from the signatures used by radar and electro-optical sensor systems, the UAV also emits RF signals. These RF signatures can be split in intentional signals for communication with the operator and un-intentional RF signals emitted by the UAV. These unintentional or spurious RF emissions are very weak but could be used to discriminate potential UAV detections from false alarms. The goal of this research was to assess the potential of exploiting spurious emissions in the classification and identification chain of mini-UAVs. It was already known that spurious signals are very weak, but the focus was on the question whether the emission pattern could be correlated to the behaviour of the UAV. In this paper experimental examples of spurious RF emission for different types of mini-UAVs and their correlation with the electronic circuits in the UAVs will be shown

A DNA Mini-Barcoding System for Authentication of Processed Fish Products.

PubMed

Shokralla, Shadi; Hellberg, Rosalee S; Handy, Sara M; King, Ian; Hajibabaei, Mehrdad

2015-10-30

Species substitution is a form of seafood fraud for the purpose of economic gain. DNA barcoding utilizes species-specific DNA sequence information for specimen identification. Previous work has established the usability of short DNA sequences-mini-barcodes-for identification of specimens harboring degraded DNA. This study aims at establishing a DNA mini-barcoding system for all fish species commonly used in processed fish products in North America. Six mini-barcode primer pairs targeting short (127-314 bp) fragments of the cytochrome c oxidase I (CO1) DNA barcode region were developed by examining over 8,000 DNA barcodes from species in the U.S. Food and Drug Administration (FDA) Seafood List. The mini-barcode primer pairs were then tested against 44 processed fish products representing a range of species and product types. Of the 44 products, 41 (93.2%) could be identified at the species or genus level. The greatest mini-barcoding success rate found with an individual primer pair was 88.6% compared to 20.5% success rate achieved by the full-length DNA barcode primers. Overall, this study presents a mini-barcoding system that can be used to identify a wide range of fish species in commercial products and may be utilized in high throughput DNA sequencing for authentication of heavily processed fish products.

Mini-titins in striated and smooth molluscan muscles: structure, location and immunological crossreactivity.

PubMed

Vibert, P; Edelstein, S M; Castellani, L; Elliott, B W

1993-12-01

Invertebrate mini-titins are members of a class of myosin-binding proteins belonging to the immunoglobulin superfamily that may have structural and/or regulatory properties. We have isolated mini-titins from three molluscan sources: the striated and smooth adductor muscles of the scallop, and the smooth catch muscles of the mussel. Electron microscopy reveals flexible rod-like molecules about 0.2 micron long and 30 A wide with a distinctive polarity. Antibodies to scallop mini-titin label the A-band and especially the A/I junction of scallop striated muscle myofibrils by indirect immunofluorescence and immuno-electron microscopy. This antibody crossreacts with mini-titins in scallop smooth and Mytilus catch muscles, as well as with proteins in striated muscles from Limulus, Lethocerus (asynchronous flight muscle), and crayfish. It labels the A/I junction (I-region in Lethocerus) in these striated muscles as well as in chicken skeletal muscle. Antibodies to the repetitive immunoglobulin-like regions and also to the kinase domain of nematode twitchin crossreact with scallop mini-titin and label the A-band of scallop myofibrils. Electron microscopy of single molecules shows that antibodies to twitchin kinase bind to scallop mini-titin near one end of the molecule, suggesting how the scallop structure might be aligned with the sequence of nematode twitchin.

Replacing the AMOR with the miniDOAS in the ammonia monitoring network in the Netherlands

NASA Astrophysics Data System (ADS)

Berkhout, Augustinus J. C.; Swart, Daan P. J.; Volten, Hester; Gast, Lou F. L.; Haaima, Marty; Verboom, Hans; Stefess, Guus; Hafkenscheid, Theo; Hoogerbrugge, Ronald

2017-11-01

In this paper we present the continued development of the miniDOAS, an active differential optical absorption spectroscopy (DOAS) instrument used to measure ammonia concentrations in ambient air. The miniDOAS has been adapted for use in the Dutch National Air Quality Monitoring Network. The miniDOAS replaces the life-expired continuous-flow denuder ammonia monitor (AMOR). From September 2014 to December 2015, both instruments measured in parallel before the change from AMOR to miniDOAS was made. The instruments were deployed at six monitoring stations throughout the Netherlands. We report on the results of this intercomparison. Both instruments show a good uptime of ca. 90 %, adequate for an automatic monitoring network. Although both instruments produce 1 min values of ammonia concentrations, a direct comparison on short timescales such as minutes or hours does not give meaningful results because the AMOR response to changing ammonia concentrations is slow. Comparisons between daily and monthly values show good agreement. For monthly averages, we find a small average offset of 0.65 ± 0.28 µg m-3 and a slope of 1.034 ± 0.028, with the miniDOAS measuring slightly higher than the AMOR. The fast time resolution of the miniDOAS makes the instrument suitable not only for monitoring but also for process studies.

Risperidone oral disintegrating mini-tablets: A robust-product for pediatrics.

PubMed

El-Say, Khalid M; Ahmed, Tarek A; Abdelbary, Maged F; Ali, Bahaa E; Aljaeid, Bader M; Zidan, Ahmed S

2015-12-01

This study was aimed at developing risperidone oral disintegrating mini-tablets (OD-mini-tablets) as age-appropriate formulations and to assess their suitability for infants and pediatric use. An experimental Box-Behnken design was applied to assure high quality of the OD-mini-tablets and reduce product variability. The design was employed to understand the influence of the critical excipient combinations on the production of OD-mini-tablets and thus guarantee the feasibility of obtaining products with dosage form uniformity. The variables selected were mannitol percent in Avicel (X1), swelling pressure of the superdisintegrant (X2), and the surface area of Aerosil as a glidant (X3). Risperidone-excipient compatibilities were investigated using FTIR and the spectra did not display any interaction. Fifteen formulations were prepared and evaluated for pre- and post-compression characteristics. The prepared OD-mini-tablet batches were also assessed for disintegration in simulated salivary fluid (SSF, pH 6.2) and in reconstituted skimmed milk. The optimized formula fulfilled the requirements for crushing strength of 5 kN with minimal friability, disintegration times of 8.4 and 53.7 s in SSF and skimmed milk, respectively. This study therefore proposes the risperidone OD-mini-tablet formula having robust mechanical properties, uniform and precise dosing of medication with short disintegration time suitable for pediatric use.

Effects of wind turbines on upland nesting birds in Conservation Reserve Program grasslands

USGS Publications Warehouse

Leddy, K.L.; Higgins, K.F.; Naugle, D.E.

1999-01-01

Grassland passerines were surveyed during summer 1995 on the Buffalo Ridge Wind Resource Area in southwestern Minnesota to determine the relative influence of wind turbines on overall densities of upland nesting birds in Conservation Reserve Program (CRP) grasslands. Birds were surveyed along 40 m fixed width transects that were placed along wind turbine strings within three CRP fields and in three CRP fields without turbines. Conservation Reserve Program grasslands without turbines and areas located 180 m from turbines supported higher densities (261.0-312.5 males/100 ha) of grassland birds than areas within 80 m of turbines (58.2-128.0 males/100 ha). Human disturbance, turbine noise, and physical movements of turbines during operation may have disturbed nesting birds. We recommend that wind turbines be placed within cropland habitats that support lower densities of grassland passerines than those found in CRP grasslands.

Wingtip vortex turbine investigation for vortex energy recovery

NASA Technical Reports Server (NTRS)

Abeyounis, William K.; Patterson, James C., Jr.; Stough, H. P., III; Wunschel, Alfred J.; Curran, Patrick D.

1990-01-01

A flight test investigation has been conducted to determine the performance of wingtip vortex turbines and their effect on aircraft performance. The turbines were designed to recover part of the large energy loss (induced drag) caused by the wingtip vortex. The turbine, driven by the vortex flow, reduces the strength of the vortex, resulting in an associated induced drag reduction. A four-blade turbine was mounted on each wingtip of a single-engine, T-tail, general aviation airplane. Two sets of turbine blades were tested, one with a 15' twist (washin) and one with no twist. Th power recovered by the turbine and the installed drag increment were measured. A trade-off between turbine power and induced drag reduction was found to be a function of turbine blade incidence angle. This test has demonstrated that the wingtip vortex turbine is an attractive alternate, as well as an emergency, power source.

CFD analysis of a Darrieus wind turbine

NASA Astrophysics Data System (ADS)

Niculescu, M. L.; Cojocaru, M. G.; Pricop, M. V.; Pepelea, D.; Dumitrache, A.; Crunteanu, D. E.

2017-07-01

The Darrieus wind turbine has some advantages over the horizontal-axis wind turbine. Firstly, its tip speed ratio is lower than that of the horizontal-axis wind turbine and, therefore, its noise is smaller, privileging their placement near populated areas. Secondly, the Darrieus wind turbine does needs no orientation mechanism with respect to wind direction in contrast to the horizontal-axis wind turbine. However, the efficiency of the Darrieus wind turbine is lower than that of the horizontal-axis wind turbine since its aerodynamics is much more complex. With the advances in computational fluids and computers, it is possible to simulate the Darrieus wind turbine more accurately to understand better its aerodynamics. For these reasons, the present papers deals with the computational aerodynamics of a Darrieus wind turbine applying the state of the art of CFD methods (anisotropic turbulence models, transition from laminar to turbulent, scale adaptive simulation) to better understand its unsteady behavior.

Wind Turbine Contingency Control Through Generator De-Rating

NASA Technical Reports Server (NTRS)

Frost, Susan; Goebel, Kai; Balas, Mark

2013-01-01

Maximizing turbine up-time and reducing maintenance costs are key technology drivers for wind turbine operators. Components within wind turbines are subject to considerable stresses due to unpredictable environmental conditions resulting from rapidly changing local dynamics. In that context, systems health management has the aim to assess the state-of-health of components within a wind turbine, to estimate remaining life, and to aid in autonomous decision-making to minimize damage to the turbine. Advanced contingency control is one way to enable autonomous decision-making by providing the mechanism to enable safe and efficient turbine operation. The work reported herein explores the integration of condition monitoring of wind turbines with contingency control to balance the trade-offs between maintaining system health and energy capture. The contingency control involves de-rating the generator operating point to achieve reduced loads on the wind turbine. Results are demonstrated using a high fidelity simulator of a utility-scale wind turbine.

Cold-air performance of compressor-drive turbine of department of energy upgraded automobile gas turbine engine. 3: Performance of redesigned turbine

NASA Technical Reports Server (NTRS)

Roelke, R. J.; Haas, J. E.

1984-01-01

The aerodynamic performance of a redesigned compressor drive turbine of the gas turbine engine is determined in air at nominal inlet conditions of 325 K and 0.8 bar absolute. The turbine is designed with a lower flow factor, higher rotor reaction and a redesigned inlet volute compared to the first turbine. Comparisons between this turbine and the originally designed turbine show about 2.3 percentage points improvement in efficiency at the same rotor tip clearance. Two versions of the same rotor are tested: (1) an as cast rotor, and (2) the same rotor with reduced surface roughness. The effect of reducing surface roughness is about one half percentage point improvement in efficiency. Tests made to determine the effect of Reynolds number on the turbine performance show no effect for the range from 100,000 to 500,000.

New technology in turbine aerodynamics.

NASA Technical Reports Server (NTRS)

Glassman, A. J.; Moffitt, T. P.

1972-01-01

Cursory review of some recent work that has been done in turbine aerodynamic research. Topics discussed include the aerodynamic effect of turbine coolant, high work-factor (ratio of stage work to square of blade speed) turbines, and computer methods for turbine design and performance prediction. Experimental cooled-turbine aerodynamics programs using two-dimensional cascades, full annular cascades, and cold rotating turbine stage tests are discussed with some typical results presented. Analytically predicted results for cooled blade performance are compared to experimental results. The problems and some of the current programs associated with the use of very high work factors for fan-drive turbines of high-bypass-ratio engines are discussed. Computer programs have been developed for turbine design-point performance, off-design performance, supersonic blade profile design, and the calculation of channel velocities for subsonic and transonic flowfields. The use of these programs for the design and analysis of axial and radial turbines is discussed.

Rotating housing turbine

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

Allouche, Erez; Jaganathan, Arun P.

The invention is a new turbine structure having a housing that rotates. The housing has a sidewall, and turbine blades are attached to a sidewall portion. The turbine may be completely open in the center, allowing space for solids and debris to be directed out of the turbine without jamming the spinning blades/sidewall. The turbine may be placed in a generator for generation of electrical current.

Airship-floated wind turbine

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

Watson, W. K.

1985-01-01

A wind turbine, by use of a tethered airship for support, may be designed for the economical recovery of power at heights of 2,000 feet or more above ground, at which height power density in the wind is typically three times the power density available to a conventionally supported wind turbine. Means can be added to such an airship-floated wind turbine which will permit its generators to be used to meet load demand even during periods of little or no wind. Described to this end is a wind turbine system which combines, among other novel features: a novel tether linemore » system which provides access for men and materials to the supporting airship while in active service, a novel system for providing additional buoyant lift at the nose of the turbine-supporting airship to offset the vertical component of tension induced in the tether line by the downwind force exerted by the turbine blades, a novel bearing assembly at the nose of the supporting airship which permits the airship to rotate as a unit with the turbine it supports without causing a similar rotation of the tether line, a novel turbine airship structure which handles concentrated loads from the turbine efficiently and also permits the safe use of hydrogen for buoyancy, a novel ''space frame'' structure which supports the turbine blades and greatly reduces blade weight, a novel system for controlling turbine blade angle of incidence and for varying blade incidene in synchrony with blade angular position abut the turbine axis to provide greater control over airship movement, a novel system for locating propellor-driven generators out at the wind turbine perimeter and for using lightweight, high-RPM generators to produce electrical energy at a power line frequency, which greatly reduces the weight required to convert turbine blade torque into useful power, and a novel system for incorporating compressed air storage and combustion turbine components into the wind turbine's generator drive systems.« less

Potential of neuro-fuzzy methodology to estimate noise level of wind turbines

NASA Astrophysics Data System (ADS)

Nikolić, Vlastimir; Petković, Dalibor; Por, Lip Yee; Shamshirband, Shahaboddin; Zamani, Mazdak; Ćojbašić, Žarko; Motamedi, Shervin

2016-01-01

Wind turbines noise effect became large problem because of increasing of wind farms numbers since renewable energy becomes the most influential energy sources. However, wind turbine noise generation and propagation is not understandable in all aspects. Mechanical noise of wind turbines can be ignored since aerodynamic noise of wind turbine blades is the main source of the noise generation. Numerical simulations of the noise effects of the wind turbine can be very challenging task. Therefore in this article soft computing method is used to evaluate noise level of wind turbines. The main goal of the study is to estimate wind turbine noise in regard of wind speed at different heights and for different sound frequency. Adaptive neuro-fuzzy inference system (ANFIS) is used to estimate the wind turbine noise levels.

Highly loaded multi-stage fan drive turbine - performance of initial seven configurations

NASA Technical Reports Server (NTRS)

Wolfmeyer, G. W.; Thomas, M. W.

1974-01-01

Experimental results of a three-stage highly loaded fan drive turbine test program are presented. A plain blade turbine, a tandem blade turbine, and a tangentially leaned stator turbine were designed for the same velocity diagram and flowpath. Seven combinations of bladerows were tested to evaluate stage performances and effects of the tandem blading and leaned stator. The plain blade turbine design point total-to-total efficiency was 0.886. The turbine with the stage three leaned stator had the same efficiency with an improved exit swirl profile and increased hub reaction. Two-stage group tests showed that the two-stage turbine with tandem stage two stator had an efficiency of 0.880 compared to 0.868 for the plain blade two-stage turbine.

Assessment of arrays of in-stream tidal turbines in the Bay of Fundy.

PubMed

Karsten, Richard; Swan, Amanda; Culina, Joel

2013-02-28

Theories of in-stream turbines are adapted to analyse the potential electricity generation and impact of turbine arrays deployed in Minas Passage, Bay of Fundy. Linear momentum actuator disc theory (LMADT) is combined with a theory that calculates the flux through the passage to determine both the turbine power and the impact of rows of turbine fences. For realistically small blockage ratios, the theory predicts that extracting 2000-2500 MW of turbine power will result in a reduction in the flow of less than 5 per cent. The theory also suggests that there is little reason to tune the turbines if the blockage ratio remains small. A turbine array model is derived that extends LMADT by using the velocity field from a numerical simulation of the flow through Minas Passage and modelling the turbine wakes. The model calculates the resulting speed of the flow through and around a turbine array, allowing for the sequential positioning of turbines in regions of strongest flow. The model estimates that over 2000 MW of power is possible with only a 2.5 per cent reduction in the flow. If turbines are restricted to depths less than 50 m, the potential power generation is reduced substantially, down to 300 MW. For large turbine arrays, the blockage ratios remain small and the turbines can produce maximum power with a drag coefficient equal to the Betz-limit value.

Can Fish Morphological Characteristics be Used to Re-design Hydroelectric Turbines?

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

Cada, G. F.; Richmond, Marshall C.

2011-07-19

Safe fish passage affects not only migratory species, but also populations of resident fish by altering biomass, biodiversity, and gene flow. Consequently, it is important to estimate turbine passage survival of a wide range of susceptible fish. Although fish-friendly turbines show promise for reducing turbine passage mortality, experimental data on their beneficial effects are limited to only a few species, mainly salmon and trout. For thousands of untested species and sizes of fish, the particular causes of turbine passage mortality and the benefits of fish-friendly turbine designs remain unknown. It is not feasible to measure the turbine-passage survival of everymore » species of fish in every hydroelectric turbine design. We are attempting to predict fish mortality based on an improved understanding of turbine-passage stresses (pressure, shear stress, turbulence, strike) and information about the morphological, behavioral, and physiological characteristics of different fish taxa that make them susceptible to the stresses. Computational fluid dynamics and blade strike models of the turbine environment are re-examined in light of laboratory and field studies of fish passage effects. Comparisons of model-predicted stresses to measured injuries and mortalities will help identify fish survival thresholds and the aspects of turbines that are most in need of re-design. The coupled model and fish morphology evaluations will enable us to make predictions of turbine-passage survival among untested fish species, for both conventional and advanced turbines, and to guide the design of hydroelectric turbines to improve fish passage survival.« less

Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE

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

Perevalov, Denis

2009-12-01

The MiniBooNE experiment at the Fermi National Accelerator Laboratory (Fermilab) was designed to search for v μ → v e neutrino oscillations at Δm 2 ~ 1 eV 2 using an intense neutrino flux with an average energy E v ~ 700 MeV. From 2002 to 2009 MiniBooNE has accumulated more than 1.0 x 10 21 protons on target (POT) in both neutrino and antineutrino modes. MiniBooNE provides a perfect platform for detailed measurements of exclusive and semiinclusive neutrino cross-sections, for which MiniBooNE has the largest samples of events up to date, such as neutral current elastic (NCE), neutral currentmore » π 0, charged current quasi-elastic (CCQE), charged current π +, and other channels. These measured cross-sections, in turn, allow to improve the knowledge of nucleon structure. This thesis is devoted to the study of NCE interactions. Neutrino-nucleus neutral current elastic scattering (vN → vN) accounts for about 18% of all neutrino interactions in MiniBooNE. Using a high-statistics, high purity sample of NCE interactions in MiniBooNE, the flux-averaged NCE differential cross-section has been measured and is being reported here. Further study of the NCE cross-section allowed for probing the structure of nuclei. The main interest in the NCE cross-section is that it may be sensitive to the strange quark contribution to the nucleon spin, Δs, this however requires a separation of NCE proton (vp → vp) from NCE neutron (vn → vn) events, which in general is a challenging task. MiniBooNE uses a Cherenkov detector, which imposes restrictions on the measured nucleon kinematic variables, mainly due to the impossibility to reconstruct the nucleon direction below the Cherenkov threshold. However, at kinetic energies above this threshold MiniBooNE is able to identify NCE proton events that do not experience final state interactions (FSI). These events were used for the Δs measurement. In this thesis MiniBooNE reports the NCE (n+p) cross-section, the measurement of the axial mass, M A, and the Δs parameter from the NCE data.« less

Neutrino-nucleus neutral current elastic interactions measurement in MiniBooNE

NASA Astrophysics Data System (ADS)

Perevalov, Denis

The MiniBooNE experiment at the Fermi National Accelerator Laboratory (Fermilab) was designed to search for numu → nu e neutrino oscillations at Deltam 2 ˜ 1 eV2 using an intense neutrino flux with an average energy Enu ˜ 700 MeV. From 2002 to 2009 MiniBooNE has accumulated more than 1.0x1021 protons on target (POT) in both neutrino and antineutrino modes. MiniBooNE provides a perfect platform for detailed measurements of exclusive and semi-inclusive neutrino cross-sections, for which MiniBooNE has the largest samples of events up to date, such as neutral current elastic (NCE), neutral current pi 0, charged current quasi-elastic (CCQE), charged current pi +, and other channels. These measured cross-sections, in turn, allow to improve the knowledge of nucleon structure. This thesis is devoted to the study of NCE interactions. Neutrino-nucleus neutral current elastic scattering (nuN → nu N) accounts for about 18% of all neutrino interactions in MiniBooNE. Using a high-statistics, high purity sample of NCE interactions in MiniBooNE, the flux-averaged NCE differential cross-section has been measured and is being reported here. Further study of the NCE cross-section allowed for probing the structure of nuclei. The main interest in the NCE cross-section is that it may be sensitive to the strange quark contribution to the nucleon spin, Deltas, this however requires a separation of NCE proton (nup → nu p) from NCE neutron (nun → nun ) events, which in general is a challenging task. MiniBooNE uses a Cherenkov detector, which imposes restrictions on the measured nucleon kinematic variables, mainly due to the impossibility to reconstruct the nucleon direction below the Cherenkov threshold. However, at kinetic energies above this threshold MiniBooNE is able to identify NCE proton events that do not experience final state interactions (FSI). These events were used for the Deltas measurement. In this thesis MiniBooNE reports the NCE (n+p) cross-section, the measurement of the axial mass, MA, and the Delta s parameter from the NCE data.

Arabidopsis Chloroplast Mini-Ribonuclease III Participates in rRNA Maturation and Intron Recycling

PubMed Central

Hotto, Amber M.; Castandet, Benoît; Gilet, Laetitia; Higdon, Andrea; Condon, Ciarán; Stern, David B.

2015-01-01

RNase III proteins recognize double-stranded RNA structures and catalyze endoribonucleolytic cleavages that often regulate gene expression. Here, we characterize the functions of RNC3 and RNC4, two Arabidopsis thaliana chloroplast Mini-RNase III-like enzymes sharing 75% amino acid sequence identity. Whereas rnc3 and rnc4 null mutants have no visible phenotype, rnc3/rnc4 (rnc3/4) double mutants are slightly smaller and chlorotic compared with the wild type. In Bacillus subtilis, the RNase Mini-III is integral to 23S rRNA maturation. In Arabidopsis, we observed imprecise maturation of 23S rRNA in the rnc3/4 double mutant, suggesting that exoribonucleases generated staggered ends in the absence of specific Mini-III-catalyzed cleavages. A similar phenotype was found at the 3′ end of the 16S rRNA, and the primary 4.5S rRNA transcript contained 3′ extensions, suggesting that Mini-III catalyzes several processing events of the polycistronic rRNA precursor. The rnc3/4 mutant showed overaccumulation of a noncoding RNA complementary to the 4.5S-5S rRNA intergenic region, and its presence correlated with that of the extended 4.5S rRNA precursor. Finally, we found rnc3/4-specific intron degradation intermediates that are probable substrates for Mini-III and show that B. subtilis Mini-III is also involved in intron regulation. Overall, this study extends our knowledge of the key role of Mini-III in intron and noncoding RNA regulation and provides important insight into plastid rRNA maturation. PMID:25724636

Peak insertion torque values of five mini-implant systems under different insertion loads.

PubMed

Quraishi, Erma; Sherriff, Martyn; Bister, Dirk

2014-06-01

To assess the effect of 1 and 3 kg insertion load on five makes of self-drilling mini-implants on peak insertion torque values to establish risk factors involved in the fracture of mini-implants. Two different loads were applied during insertion of 40 mini-implants from five different manufacturers (Dual Top(™) (1·6×8 mm), Infinitas(™) (1·5×9 mm), Ortho Easy(™) (1·7×8 mm), Spider Screw(™) (1·5×8 mm) and Vector TAS(™) (1·4×8 mm)) into acrylic blocks at 8 rev/min utilizing a Motorized Torque Measurement Stand. Peak insertion torque values for both loads were highest for Vector TAS followed by Ortho Easy and Dual Top and were nearly three times higher than Infinitas (original version) and Spider Screws(TM). The log-rank test showed statistically significant differences for both loads for Vector TAS, Ortho Easy and Spider Screws. Unlike other designs tested, both tapered mini-implant designs (Spider Screw and Infinitas) showed a tendency to buckle in the middle of the body but fractured at the tip. Non-tapered mini-implants fractured at significantly higher torque values compared to tapered designs under both loads. Increased pressure resulted in slightly higher maximum torque values at fracture for some of the mini-implant designs, although this is unlikely to be of clinical relevance. Tripling insertion pressure from 1 to 3 kg increased the risk of bending tapered mini-implants before fracture. © 2014 British Orthodontic Society.

New technology in turbine aerodynamics

NASA Technical Reports Server (NTRS)

Glassman, A. J.; Moffitt, T. P.

1972-01-01

A cursory review is presented of some of the recent work that has been done in turbine aerodynamic research at NASA-Lewis Research Center. Topics discussed include the aerodynamic effect of turbine coolant, high work-factor (ratio of stage work to square of blade speed) turbines, and computer methods for turbine design and performance prediction. An extensive bibliography is included. Experimental cooled-turbine aerodynamics programs using two-dimensional cascades, full annular cascades, and cold rotating turbine stage tests are discussed with some typical results presented. Analytically predicted results for cooled blade performance are compared to experimental results. The problems and some of the current programs associated with the use of very high work factors for fan-drive turbines of high-bypass-ratio engines are discussed. Turbines currently being investigated make use of advanced blading concepts designed to maintain high efficiency under conditions of high aerodynamic loading. Computer programs have been developed for turbine design-point performance, off-design performance, supersonic blade profile design, and the calculation of channel velocities for subsonic and transonic flow fields. The use of these programs for the design and analysis of axial and radial turbines is discussed.

A Take Stock of Turbine Blades Failure Phenomenon

NASA Astrophysics Data System (ADS)

Roy, Abhijit

2018-02-01

Turbine Blade design and engineering is one of the most complicated and important aspects of turbine technology. Experiments with blades can be simple or very complicated, depending upon parameters of analysis. Turbine blades are subjected to vigorous environments, such as high temperatures, high stresses, and a potentially high vibration environment. All these factors can lead to blade failures, which can destroy the turbine, and engine, so careful design is the prime consideration to resist those conditions. A high cycle of fatigue of compressor and turbine blades due to high dynamic stress caused by blade vibration and resonance within the operating range of machinery is common failure mode for turbine machine. Continuous study and investigation on failure of turbine blades are going on since last five decades. Some review papers published during these days aiming to present a review on recent studies and investigations done on failures of turbine blades. All the detailed literature related with the turbine blades has not been described but emphasized to provide all the methodologies of failures adopted by various researches to investigate turbine blade. This paper illustrate on various factors of failure.

11. Power room, view of Westinghouse steam turbine: turbine RPM6,000, ...

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

11. Power room, view of Westinghouse steam turbine: turbine RPM-6,000, governor RPM-1017, turbine number 8695, manufactured by Westinghouse Electric Manufacturing company, East Pittsburg, Pennsylvania - Norfolk Manufacturing Company Cotton Mill, 90 Milton Street, Dedham, Norfolk County, MA

78 FR 17738 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing and Immediate Effectiveness...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

... customer bases of potential product users have indicated a preference that premium pricing for Mini Options... market participants clarity as to the minimum pricing increments for Mini Options, the filing would harmonize penny pricing between Mini Options and standard options on the same security. \\4\\ See Securities...

78 FR 17970 - Self-Regulatory Organizations; Miami International Securities Exchange LLC; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-25

... product users and they have indicated a preference that premium pricing for mini-options match what is... market participants clarity as to the minimum pricing increments for mini-options, the filing would harmonize penny pricing between mini-options and standard options on the same security. \\3\\ See Securities...

Bridging the Gap in Volleyball. From Basic Instruction to Game Play.

ERIC Educational Resources Information Center

Dawson, Linda; Polvino, Geri

1982-01-01

Using volleyball "mini games," which emphasize, one at a time, skills needed to play volleyball, helps students to develop skills needed to play. Mini games described are: (1) forearm pass; (2) overhand pass; (3) overhand pass; (4) overhand serve; (5) mini volleyball; and (6) alternate court set-up. (CJ)

Mini-rack testbed evaluation

NASA Technical Reports Server (NTRS)

Gosbee, John; Stegmann, Barbara; Guess, Terrell M.

1991-01-01

The goal was to characterize the Health Maintenance Facility (HMF)-like mini-racks and drawers onboard the KC-135 as a test bed for the Space Station Freedom HMF racks. An additional goal was to evaluate the attachments, mounting points, and inner drawer assemblies of the mini-racks for various medical equipment and supplies. Results and recommendations are given.

Shortcuts for Pilot Testing Instructional Materials.

ERIC Educational Resources Information Center

Howe, R. John; Pearlstein, Gloria

1995-01-01

A mini-pilot test was conducted by the Department of Labor's Employment Standards Administration to develop training on enforcing the Federal Family and Medical Leave Act. The situation that necessitated the test is presented; mini-pilot test examples are explained; and pros and cons of the mini-pilots are examined. A sidebar contains suggestions…

Protective Factor Screening for Prevention Practice: Sensitivity and Specificity of the Dessa-Mini

ERIC Educational Resources Information Center

Shapiro, Valerie B.; Kim, B. K. Elizabeth; Robitaille, Jennifer L.; LeBuffe, Paul A.

2017-01-01

The Devereux Student Strengths Assessment Mini (DESSA-Mini; Naglieri, LeBuffe, & Shapiro, 2011/2014) was designed to overcome practical obstacles to universal prevention screening. This article seeks to determine whether an entirely strength-based, 8-item screening instrument achieves technical accuracy in routine practice. Data come from a…

Mini-Concerts: Creating Space for Student-Initiated Performance

ERIC Educational Resources Information Center

Gifford, Cody; Johnson, Erik

2015-01-01

Mini-concerts are regularly occurring, low-stakes curricular events in the classroom where students perform music of their choice for their peers. An idea generated by music educators in domestic and international K-12 schools who strive to meet the needs of diverse student populations, mini-concerts have helped generate student excitement and…

Gender and Self-Employment: The Role of Mini-Companies

ERIC Educational Resources Information Center

Johansen, Vegard

2016-01-01

Purpose: The purpose of this paper is to evaluate to what degree participation in mini-companies impact young women and men with regard to the perceived desirability and perceived feasibility of self-employment. The Company Programme (CP) is the largest mini-company scheme in European secondary school. Design/methodology/approach: The data derived…

The Genesis of Creative Greatness: Mini-C and the Expert Performance Approach

ERIC Educational Resources Information Center

Beghetto, Ronald A.; Kaufman, James C.

2007-01-01

The authors' recent theoretical work has focused on developing the construct of mini-c creativity and illustrating how all levels of creative performance follow a trajectory that starts with novel and personally meaningful interpretations (mini-c), which can then progress to intrapersonally judged novel and meaningful contributions (little-c) and…

INNOVATIVE TECHNOLOGY VERIFICATION REPORT XRF TECHNOLOGIES FOR MEASURING TRACE ELEMENTS IN SOIL AND SEDIMENT RIGAKU ZSX MINI 11 XRF ANALYZER

EPA Science Inventory

The Rigaku ZSX Mini II (ZSX Mini II) XRF Services x-ray fluorescence (XRF) analyzer was demon-strated under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program. The field portion of the demonstration was conducted in January 2...

Mini-Digest of Education Statistics, 2008. NCES 2009-021

ERIC Educational Resources Information Center

Snyder, Thomas D.

2009-01-01

This publication is the 14th edition of the "Mini-Digest of Education Statistics," a pocket-sized compilation of statistical information covering the broad field of American education from kindergarten through graduate school. The "Mini-Digest" is designed as an easy reference for materials found in much greater detail in the…

Validation and Diagnostic Efficiency of the Mini-SPIN in Spanish-Speaking Adolescents

PubMed Central

Garcia-Lopez, LuisJoaquín; Moore, Harry T. A.

2015-01-01

Objectives Social Anxiety Disorder (SAD) is one of the most common mental disorders in adolescence. Many validated psychometric tools are available to diagnose individuals with SAD efficaciously. However, there is a demand for shortened self-report instruments that identify adolescents at risk of developing SAD. We validate the Mini-SPIN and its diagnostic efficiency in overcoming this problem in Spanish-speaking adolescents in Spain. Methods The psychometric properties of the 3-item Mini-SPIN scale for adolescents were assessed in a community (study 1) and clinical sample (study 2). Results Study 1 consisted of 573 adolescents, and found the Mini-SPIN to have appropriate internal consistency and high construct validity. Study 2 consisted of 354 adolescents (147 participants diagnosed with SAD and 207 healthy controls). Data revealed that the Mini-SPIN has good internal consistency, high construct validity and adequate diagnostic efficiency. Conclusions Our findings suggest that the Mini-SPIN has good psychometric properties on clinical and healthy control adolescents and general population, which indicates that it can be used as a screening tool in Spanish-speaking adolescents. Cut-off scores are provided. PMID:26317695

A regulatory toolbox of MiniPromoters to drive selective expression in the brain

PubMed Central

Portales-Casamar, Elodie; Swanson, Douglas J.; Liu, Li; de Leeuw, Charles N.; Banks, Kathleen G.; Ho Sui, Shannan J.; Fulton, Debra L.; Ali, Johar; Amirabbasi, Mahsa; Arenillas, David J.; Babyak, Nazar; Black, Sonia F.; Bonaguro, Russell J.; Brauer, Erich; Candido, Tara R.; Castellarin, Mauro; Chen, Jing; Chen, Ying; Cheng, Jason C. Y.; Chopra, Vik; Docking, T. Roderick; Dreolini, Lisa; D'Souza, Cletus A.; Flynn, Erin K.; Glenn, Randy; Hatakka, Kristi; Hearty, Taryn G.; Imanian, Behzad; Jiang, Steven; Khorasan-zadeh, Shadi; Komljenovic, Ivana; Laprise, Stéphanie; Liao, Nancy Y.; Lim, Jonathan S.; Lithwick, Stuart; Liu, Flora; Liu, Jun; Lu, Meifen; McConechy, Melissa; McLeod, Andrea J.; Milisavljevic, Marko; Mis, Jacek; O'Connor, Katie; Palma, Betty; Palmquist, Diana L.; Schmouth, Jean-François; Swanson, Magdalena I.; Tam, Bonny; Ticoll, Amy; Turner, Jenna L.; Varhol, Richard; Vermeulen, Jenny; Watkins, Russell F.; Wilson, Gary; Wong, Bibiana K. Y.; Wong, Siaw H.; Wong, Tony Y. T.; Yang, George S.; Ypsilanti, Athena R.; Jones, Steven J. M.; Holt, Robert A.; Goldowitz, Daniel; Wasserman, Wyeth W.; Simpson, Elizabeth M.

2010-01-01

The Pleiades Promoter Project integrates genomewide bioinformatics with large-scale knockin mouse production and histological examination of expression patterns to develop MiniPromoters and related tools designed to study and treat the brain by directed gene expression. Genes with brain expression patterns of interest are subjected to bioinformatic analysis to delineate candidate regulatory regions, which are then incorporated into a panel of compact human MiniPromoters to drive expression to brain regions and cell types of interest. Using single-copy, homologous-recombination “knockins” in embryonic stem cells, each MiniPromoter reporter is integrated immediately 5′ of the Hprt locus in the mouse genome. MiniPromoter expression profiles are characterized in differentiation assays of the transgenic cells or in mouse brains following transgenic mouse production. Histological examination of adult brains, eyes, and spinal cords for reporter gene activity is coupled to costaining with cell-type–specific markers to define expression. The publicly available Pleiades MiniPromoter Project is a key resource to facilitate research on brain development and therapies. PMID:20807748

Validation and Diagnostic Efficiency of the Mini-SPIN in Spanish-Speaking Adolescents.

PubMed

Garcia-Lopez, LuisJoaquín; Moore, Harry T A

2015-01-01

Social Anxiety Disorder (SAD) is one of the most common mental disorders in adolescence. Many validated psychometric tools are available to diagnose individuals with SAD efficaciously. However, there is a demand for shortened self-report instruments that identify adolescents at risk of developing SAD. We validate the Mini-SPIN and its diagnostic efficiency in overcoming this problem in Spanish-speaking adolescents in Spain. The psychometric properties of the 3-item Mini-SPIN scale for adolescents were assessed in a community (study 1) and clinical sample (study 2). Study 1 consisted of 573 adolescents, and found the Mini-SPIN to have appropriate internal consistency and high construct validity. Study 2 consisted of 354 adolescents (147 participants diagnosed with SAD and 207 healthy controls). Data revealed that the Mini-SPIN has good internal consistency, high construct validity and adequate diagnostic efficiency. Our findings suggest that the Mini-SPIN has good psychometric properties on clinical and healthy control adolescents and general population, which indicates that it can be used as a screening tool in Spanish-speaking adolescents. Cut-off scores are provided.

The Formation of Mini-Neptunes

NASA Astrophysics Data System (ADS)

Venturini, Julia; Helled, Ravit

2017-10-01

Mini-Neptunes seem to be common planets. In this work we investigate the possible formation histories and predicted occurrence rates of mini-Neptunes, assuming that the planets form beyond the iceline. We consider pebble and planetesimal accretion accounting for envelope enrichment and two different opacity conditions. We find that the formation of mini-Neptunes is a relatively frequent output when envelope enrichment by volatiles is included, and that there is a “sweet spot” for mini-Neptune formation with a relatively low solid accretion rate of ˜10-6 M ⊕ yr-1. This rate is typical for low/intermediate-mass protoplanetary disks and/or disks with low metallicities. With pebble accretion, envelope enrichment and high opacity favor the formation of mini-Neptunes, with more efficient formation at large semimajor axes (˜30 au) and low disk viscosities. For planetesimal accretion, such planets can also form without enrichment, with the opacity being a key aspect in the growth history and favorable formation location. Finally, we show that the formation of Neptune-like planets remains a challenge for planet formation theories.

Adaptation of a Turbine Test Facility to High-Temperature Research (Adaptation d’un banc de Turbine aux Recherches pour les Hautes Temperatures,

DTIC Science & Technology

1980-12-19

Des hautes temperatures devant turbine sur turborgacteur et turbines A gaz. (High turbine inlet temperatures in turbo - jet engines and gas turbines ... turbo - jet engines .) Revue Gn(rale de Thermique, No. 166, October 1975 15 D. Arnal Etude exprimentale et thgorique de la transition de la couche J.C...r AD-AIOl 374 ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUBH (ENGLAND) F/B 10/1 ADAPTATION OF A TURBINE TEST FACILITY TO HIGH-TEMPERATURE RESEA--ETC(U) DEC

A Study on Aircraft Structure and Jet Engine

NASA Astrophysics Data System (ADS)

Park, Gil Moon; Park, Hwan Kyu; Kim, Jong Il; Kim, Jin Won; Kim, Jin Heung; Lee, Moo Seok; Chung, Nak Kyu

1985-12-01

The one of critical factor in gas turbine engine performance is high turbine inlet gas temperature. Therefore, the turbine rotor has so many problems which must be considered such as the turbine blade cooling, thermal stress of turbine disk due to severe temperature gradient, turbine rotor tip clearance, under the high operation temperature. The purpose of this study is to provide the temperature distribution and heat flux in turbine disk which is required to considered premensioned problem by the Finite Difference Method and the Finite Element Methods on the steady state condition.

Gas Dynamic Modernization of Axial Uncooled Turbine by Means of CFD and Optimization Software

NASA Astrophysics Data System (ADS)

Marchukov, E. Yu; Egorov, I. N.

2018-01-01

The results of multicriteria optimization of three-stage low-pressure turbine are described in the paper. The aim of the optimization is to improve turbine operation process by three criteria: turbine outlet flow angle, value of residual swirl at the turbine outlet, and turbine efficiency. Full reprofiling of all blade rows is carried out while solving optimization problem. Reprofiling includes a change in both shape of flat blade sections (profiles) and three-dimensional shape of the blades. The study is carried out with 3D numerical models of turbines.

Partial admission effect on the performance and vibration of a supersonic impulse turbine

NASA Astrophysics Data System (ADS)

Lee, Hang Gi; Shin, Ju Hyun; Choi, Chang-Ho; Jeong, Eunhwan; Kwon, Sejin

2018-04-01

This study experimentally investigates the effects of partial admission on the performance and vibration outcomes of a supersonic impulse turbine with circular nozzles. The turbine of a turbopump for a gas-generator-type liquid rocket engine in the Korea Space Launch Vehicle-II is of the supersonic impulse type with the partial admission configuration for obtaining a high specific power. Partial admission turbines with a low-flow-rate working gas exhibit benefits over turbines with full admission, such as loss reduction, ease of controllability of the turbine power output, and simple turbine configurations with separate starting sections. However, the radial force of the turbine rotor due to the partial admission causes an increase in turbine vibration. Few experimental studies have previously been conducted regarding the partial admission effects on supersonic impulse turbines with circular nozzles. In the present study, performance tests of supersonic impulse turbines with circular nozzles were conducted for various partial admission ratios using a turbine test facility with high-pressure air in order to investigate the resulting aerodynamic performance and vibration. Four types of turbines with partial admission ratios of 0.17, 0.42, 0.75 and 0.83 were tested. Results show that the efficiencies at the design point increase linearly as the partial admission ratios increase. Moreover, as the velocity ratios increase, the difference in efficiency from the reference turbine with a partial admission ratio of 0.83 becomes increasingly significant, and the magnitudes of these differences are proportional to the square of the velocity ratios. Likewise, the decrease in the partial admission ratio results in an increase in the turbine vibration level owing to the increase in the radial force.

Method for Making Measurements of the Post-Combustion Residence Time in a Gas Turbine Engine

NASA Technical Reports Server (NTRS)

Miles, Jeffrey H (Inventor)

2015-01-01

A system and method of measuring a residence time in a gas-turbine engine is provided, whereby the method includes placing pressure sensors at a combustor entrance and at a turbine exit of the gas-turbine engine and measuring a combustor pressure at the combustor entrance and a turbine exit pressure at the turbine exit. The method further includes computing cross-spectrum functions between a combustor pressure sensor signal from the measured combustor pressure and a turbine exit pressure sensor signal from the measured turbine exit pressure, applying a linear curve fit to the cross-spectrum functions, and computing a post-combustion residence time from the linear curve fit.

Web-based software tool for constraint-based design specification of synthetic biological systems.

PubMed

Oberortner, Ernst; Densmore, Douglas

2015-06-19

miniEugene provides computational support for solving combinatorial design problems, enabling users to specify and enumerate designs for novel biological systems based on sets of biological constraints. This technical note presents a brief tutorial for biologists and software engineers in the field of synthetic biology on how to use miniEugene. After reading this technical note, users should know which biological constraints are available in miniEugene, understand the syntax and semantics of these constraints, and be able to follow a step-by-step guide to specify the design of a classical synthetic biological system-the genetic toggle switch.1 We also provide links and references to more information on the miniEugene web application and the integration of the miniEugene software library into sophisticated Computer-Aided Design (CAD) tools for synthetic biology ( www.eugenecad.org ).

Analysis of turbine-grid interaction of grid-connected wind turbine using HHT

NASA Astrophysics Data System (ADS)

Chen, A.; Wu, W.; Miao, J.; Xie, D.

2018-05-01

This paper processes the output power of the grid-connected wind turbine with the denoising and extracting method based on Hilbert Huang transform (HHT) to discuss the turbine-grid interaction. At first, the detailed Empirical Mode Decomposition (EMD) and the Hilbert Transform (HT) are introduced. Then, on the premise of decomposing the output power of the grid-connected wind turbine into a series of Intrinsic Mode Functions (IMFs), energy ratio and power volatility are calculated to detect the unessential components. Meanwhile, combined with vibration function of turbine-grid interaction, data fitting of instantaneous amplitude and phase of each IMF is implemented to extract characteristic parameters of different interactions. Finally, utilizing measured data of actual parallel-operated wind turbines in China, this work accurately obtains the characteristic parameters of turbine-grid interaction of grid-connected wind turbine.

Particle image and acoustic Doppler velocimetry analysis of a cross-flow turbine wake

NASA Astrophysics Data System (ADS)

Strom, Benjamin; Brunton, Steven; Polagye, Brian

2017-11-01

Cross-flow turbines have advantageous properties for converting kinetic energy in wind and water currents to rotational mechanical energy and subsequently electrical power. A thorough understanding of cross-flow turbine wakes aids understanding of rotor flow physics, assists geometric array design, and informs control strategies for individual turbines in arrays. In this work, the wake physics of a scale model cross-flow turbine are investigated experimentally. Three-component velocity measurements are taken downstream of a two-bladed turbine in a recirculating water channel. Time-resolved stereoscopic particle image and acoustic Doppler velocimetry are compared for planes normal to and distributed along the turbine rotational axis. Wake features are described using proper orthogonal decomposition, dynamic mode decomposition, and the finite-time Lyapunov exponent. Consequences for downstream turbine placement are discussed in conjunction with two-turbine array experiments.

Miniature cryogenic expansion turbines - A review

NASA Astrophysics Data System (ADS)

Sixsmith, H.

Lord Rayleigh (1898) has first suggested the use of a turbine instead of a piston expander for the liquification of air. The development of expansion turbines is discussed, taking into account the first successful commercial application for cryogenic expansion turbines in Germany, Kapitza's turbine, work on much smaller turbines conducted in England, the development of a helium expansion turbine at the National Bureau of Standards, the development of small turboexpanders in Switzerland, the development of gas bearing expansion turbines, and the development of a small turboexpander similar to designs developed at the National Bureau of Standards. The reliability of cryogenic expansion turbines is discussed. It is found that applications for helium refrigerators and the demand for them would greatly increase if the reliability of these devices could be improved. Such a development would be crucial for the adoption of superconducting machinery by industry.

Turbine Engine Hot Section Technology, 1985

NASA Technical Reports Server (NTRS)

1985-01-01

The Turbine Engine Section Technology (HOST) Project Office of the Lewis Research Center sponsored a workshop to discuss current research pertinent to turbine engine hot section durability problems. Presentations were made concerning hot section environment and the behavior of combustion liners, turbine blades, and turbine vanes.

A WRKY transcription factor recruits the SYG1-like protein SHB1 to activate gene expression and seed cavity enlargement.

PubMed

Kang, Xiaojun; Li, Wei; Zhou, Yun; Ni, Min

2013-01-01

Seed development in Arabidopsis and in many dicots involves an early proliferation of the endosperm to form a large embryo sac or seed cavity close to the size of the mature seed, followed by a second phase during which the embryo grows and replaces the endosperm. Short hypocotyl under BLUE1 (SHB1) is a member of the SYG1 protein family in fungi, Caenorhabditis elegans, flies, and mammals. SHB1 gain-of-function enhances endosperm proliferation, increases seed size, and up-regulates the expression of the WRKY transcription factor gene MINISEED3 (MINI3) and the LRR receptor kinase gene HAIKU2 (IKU2). Mutations in either IKU2 or MINI3 retard endosperm proliferation and reduce seed size. However, the molecular mechanisms underlying the establishment of the seed cavity and hence the seed size remain largely unknown. Here, we show that the expression of MINI3 and IKU2 is repressed before fertilization and after 4 days after pollination (DAP), but is activated by SHB1 from 2 to 4 DAP prior to the formation of the seed cavity. SHB1 associates with their promoters but without a recognizable DNA binding motif, and this association is abolished in mini3 mutant. MINI3 binds to W-boxes in, and recruits SHB1 to, its own and IKU2 promoters. Interestingly, SHB1, but not MINI3, activates transcription of pMINI3::GUS or pIKU2::GUS. We reveal a critical developmental switch through the activation of MINI3 expression by SHB1. The recruitment of SHB1 by MINI3 to its own and IKU2 promoters represents a novel two-step amplification to counter the low expression level of IKU2, which is a trigger for endosperm proliferation and seed cavity enlargement.

Temporary anchorage devices (TADs) in orthodontics: review of the factors that influence the clinical success rate of the mini-implants.

PubMed

Leo, M; Cerroni, L; Pasquantonio, G; Condò, S G; Condò, R

2016-01-01

The mini-implant, temporary anchorage devices (TADS), are now a common method of treatment in Orthodontics with versatility, minimal invasiveness and the relationship between costs and benefits that they offer even today. Skeletal anchorage has, to a large degree, replaced conventional anchorage in situations where anchorage is considered either critical, insufficient, or likely to result in undesirable side effects such as vertical displacements generated by inter-maxillary force systems. The objective of this study is to carry out a review about the factors that seem affect the success or failure rate of orthodontic mini-implants. A computerized literature review was performed by searching the MEDLINE database (Entrez PubMed, www.ncbi.nlm.nih.gov), Google Scholar, Scopus, Cochrane Central Register of Controlled Trials, Isi Web of Knowledge until March 2016 . The main subject heading "orthodontics" was combined with these keywords mini-implant, mini-screw, micro-implants, mini-implant success rate, mini-implant failure rate, skeletal anchorage, temporary anchorage device (TADS). In the selection process, abstracts were initially read independently by two researchers to identify potentially eligible full text papers which were then retrieved and assessed in order to decide on the final inclusion. The clinical success of orthodontic anchorage by mini-implants depends on the stability of the miniscrews used for fixation. For good stability, the application site must provide bone of good quantity and quality. We can reasonably assume that the stability of the anchorage of the mini-implants could be optimized by selecting a position with particular characteristics of quality and quantity of bone, in relation to cortical and total mandibular and jaw bone thickness. These expected informations are important because they indicates that the bone quality and quantity are significant when considering an implant placement site, but also that there are other confounding factors influencing the success rate.

Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study.

PubMed

Aunmeungtong, W; Khongkhunthian, P; Rungsiyakull, P

2016-01-01

Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant should exhibit the same behavior to chewing force.

The use of mini-samples in palaeomagnetism

NASA Astrophysics Data System (ADS)

Böhnel, Harald; Michalk, Daniel; Nowaczyk, Norbert; Naranjo, Gildardo Gonzalez

2009-10-01

Rock cores of ~25 mm diameter are widely used in palaeomagnetism. Occasionally smaller diameters have been used as well which represents distinct advantages in terms of throughput, weight of equipment and core collections. How their orientation precision compares to 25 mm cores, however, has not been evaluated in detail before. Here we compare the site mean directions and their statistical parameters for 12 lava flows sampled with 25 mm cores (standard samples, typically 8 cores per site) and with 12 mm drill cores (mini-samples, typically 14 cores per site). The site-mean directions for both sample sizes appear to be indistinguishable in most cases. For the mini-samples, site dispersion parameters k on average are slightly lower than for the standard samples reflecting their larger orienting and measurement errors. Applying the Wilcoxon signed-rank test the probability that k or α95 have the same distribution for both sizes is acceptable only at the 17.4 or 66.3 per cent level, respectively. The larger mini-core numbers per site appears to outweigh the lower k values yielding also slightly smaller confidence limits α95. Further, both k and α95 are less variable for mini-samples than for standard size samples. This is interpreted also to result from the larger number of mini-samples per site, which better averages out the detrimental effect of undetected abnormal remanence directions. Sampling of volcanic rocks with mini-samples therefore does not present a disadvantage in terms of the overall obtainable uncertainty of site mean directions. Apart from this, mini-samples do present clear advantages during the field work, as about twice the number of drill cores can be recovered compared to 25 mm cores, and the sampled rock unit is then more widely covered, which reduces the contribution of natural random errors produced, for example, by fractures, cooling joints, and palaeofield inhomogeneities. Mini-samples may be processed faster in the laboratory, which is of particular advantage when carrying out palaeointensity experiments.

Review of fluid and control technology of hydraulic wind turbines

NASA Astrophysics Data System (ADS)

Cai, Maolin; Wang, Yixuan; Jiao, Zongxia; Shi, Yan

2017-09-01

This study examines the development of the fluid and control technology of hydraulic wind turbines. The current state of hydraulic wind turbines as a new technology is described, and its basic fluid model and typical control method are expounded by comparing various study results. Finally, the advantages of hydraulic wind turbines are enumerated. Hydraulic wind turbines are expected to become the main development direction of wind turbines.

Best Practices for Fuel System Contamination Detection and Remediation

DTIC Science & Technology

2015-12-14

Valve Fyre Ring GR DBB Style Plug Valve Gasket SS graphite Spiral DBB Style Plug Valve O- rings & slip seals VI DBB Style Plug Valve Packing gland...Pumps Impeller Key SS Vertical Turbine Pumps Impeller Retaining Ring SS Vertical Turbine Pumps Impellers (Electroless Nickel Plating) DI Vertical... Turbine Pumps Line Shaft SS Vertical Turbine Pumps Lineshaft Bearing CA Vertical Turbine Pumps Mating Ring Si-C Vertical Turbine Pumps Mechanical

Best Practices for Fuel System Contamination Detection and Remediation

DTIC Science & Technology

2016-01-15

Valve Fyre Ring GR DBB Style Plug Valve Gasket SS graphite Spiral DBB Style Plug Valve O- rings & slip seals VI DBB Style Plug Valve Packing gland...Pumps Impeller Key SS Vertical Turbine Pumps Impeller Retaining Ring SS Vertical Turbine Pumps Impellers (Electroless Nickel Plating) DI Vertical... Turbine Pumps Line Shaft SS Vertical Turbine Pumps Lineshaft Bearing CA Vertical Turbine Pumps Mating Ring Si-C Vertical Turbine Pumps Mechanical

A wind-tunnel investigation of wind-turbine wakes in different yawed and loading conditions

NASA Astrophysics Data System (ADS)

Bastankhah, Majid; Porté-Agel, Fernando

2015-04-01

Wind-turbine wakes have negative effects on wind-farm performance. They are associated with: (a) the velocity deficit, which reduces the generated power of downwind turbines; and (b) the turbulence level, which increases the fatigue loads on downwind turbines. Controlling the yaw angle of turbines can potentially improve the performance of wind farms by deflecting the wake away from downwind turbines. However, except for few studies, wakes of yawed turbines still suffer from the lack of systematic research. To fill this research gap, we performed wind-tunnel experiments in the recirculating boundary-layer wind tunnel at the WIRE Laboratory of EPFL to better understand the wakes of yawed turbines. High-resolution stereoscopic particle image-velocimetry (S-PIV) was used to measure three velocity components in a horizontal plane located downwind of a horizontal-axis, three-blade model turbine. A servo-controller was connected to the DC generator of the turbine, which allowed us to apply different loadings. The power and thrust coefficients of the turbine were also measured for each case. These power and thrust measurements together with the highly-resolved flow measurements enabled us to study different wake characteristics such as the energy entrainment from the outer flow into the wake, the wake deflection and the helicoidal tip vortices for yawed turbines.

FY17 Accomplishments - Testing Facilities and Capabilities at SWiFT, SNL

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

Berg, Jonathan Charles

The Scaled Wind Farm Technologies (SWiFT) facility operated by Sandia National Laboratories (SNL) has, in support of the Atmosphere to electrons (A2e) research program, acquired measurements of wind turbine wake dynamics under various atmospheric conditions and while interacting with a downstream wind turbine. SNL researchers, in collaboration with National Renewable Energy Laboratory (NREL) researchers, installed a customized LIDAR system created by the Technical University of Denmark (DTU) in one of the SWiFT wind turbines (Figure 1) and operated that turbine with intentional yaw-versus-winddirection misalignment to study the behavior of the turbine wake under numerous combinations of atmospheric conditions and turbinemore » yaw offsets. The DTU-customized LIDAR provided detailed measurements of the wake’s shape and location at many distances downwind of the turbine (Figure 2). These measurements will benefit wind energy researchers looking to understand wind turbine wake behavior and improve modeling and simulation of wake dynamics, including the “wake steering” affect that is observed when turbine yaw offset is controlled. During the test campaign, two SWiFT wind turbines were operated at the same time to observe the influence of the turbines on each other as the wake of the upwind turbine was observed sweeping over and interacting with the downwind turbine.« less

Experimental investigation on performance of crossflow wind turbine as effect of blades number

NASA Astrophysics Data System (ADS)

Kurniawati, Diniar Mungil; Tjahjana, Dominicus Danardono Dwi Prija; Santoso, Budi

2018-02-01

Urban living is one of the areas with large electrical power consumption that requires a power supply that is more than rural areas. The number of multi-storey buildings such as offices, hotels and several other buildings that caused electricity power consumption in urban living is very high. Therefore, energy alternative is needed to replace the electricity power consumption from government. One of the utilization of renewable energy in accordance with these conditions is the installation of wind turbines. One type of wind turbine that is now widely studied is a crossflow wind turbines. Crossflow wind turbine is one of vertical axis wind turbine which has good self starting at low wind speed condition. Therefore, the turbine design parameter is necessary to know in order to improve turbine performance. One of wind turbine performance parameter is blades number. The main purpose of this research to investigate the effect of blades number on crossflow wind turbine performance. The design of turbine was 0.4 × 0.4 m2 tested by experimental method with configuration on three kinds of blades number were 8,16 and 20. The turbine investigated at low wind speed on 2 - 5 m/s. The result showed that best performance on 16 blade number.

Orthodontic mechanics using mini-implant measured by FBG

NASA Astrophysics Data System (ADS)

Trannin, Pamela G.; Milczewski, Maura S.; de Oliveira, Walmir; Guariza Filho, Odilon; Lopes, Stephani C. P. S.; Kalinowski, Hypolito J.

2015-07-01

The magnitude of the force generated during orthodontic mechanics anchored in mini-implant in a maxilla model was analyzed. Data was collected during the insertion of the mini-implant and at the moment of applying forces to the structure of the maxilla and dentition. To obtain quantitative results, the Fibre Bragg Gratings (FBG) were inserted in an elastomeric material reproducing a maxilla model. It was observed levels of forces of approximately 3,78N next to the root of first premolar by the insertion of the mini-implant and different levels of the force to different orthodontic mechanics applied on the dental system.

Giant mini-clusters as possible origin of halo phenomena observed in super-families

NASA Technical Reports Server (NTRS)

1985-01-01

Among 91 mini-clusters from 30 high energy Chiron-type families in Chacaltaya emulsion chambers, there were observed several extremely large multiplicity clusters in the highest energy range, far beyond the average of ordinary type clusters. Some details of microscopic observation of those giant mini-clusters in nuclear emulsion plates and some phenomenological regularity found in common among them are described. Such giant mini-clusters are possible candidates for the origin of narrow symmetric single halo phenomena in X-ray films which are frequently observed in super-families of visible energy greater than 1,000 TeV.

Rare complication of needleless mini-sling procedure: Case report.

PubMed

Karalar, Mustafa; Keles, Ibrahim; Unlu, Serdar; Sarici, Hasmet; Kose, Mesut; Ay, Cemil

2017-01-01

The mini-sling procedure is a widely used, minimally invasive treatment for stress urinary incontinence. While bladder perforation and stone formation over the mesh is not an expected complication of the mini-sling procedure, in this case, we report on the management of bladder calculi formed over the mesh, which was passed through the bladder while applying the mini-sling procedure, and was eventually removed using holmium laser. Performing cystoscopy in patients with irritative and obstructive symptoms after the sling procedure will help confirm bladder perforation, and an endoscopic approach using holmium laser is an effective treatment.

Hydroacoustic Assessment of Behavioral Responses by Fish Passing Near an Operating Tidal Turbine in the East River, New York

DOE PAGES

Bevelhimer, Mark; Scherelis, Constantin C.; Colby, Jonathan; ...

2017-06-13

An important environmental issue facing the marine and hydrokinetic energy industry is whether fish that encounter underwater energy devices are likely to be struck and injured by moving components, primarily rotating turbine blades. The automated analysis of nearly 3 weeks of multibeam hydroacoustics data identified about 35,000 tracks of fish passing a tidal turbine in the East River, New York. These tracks included both individual fish and schools during periods with the turbine absent, the turbine present and operating, and the turbine present but not operating. The density of fish in the sampled area when the turbine was absent wasmore » roughly twice the density observed when the turbine was in place, particularly when the turbine was operating. This suggests that some avoidance occurred before fish were close enough to the turbine to be observed by the hydroacoustics system. Various measures of swimming behavior (direction, velocity, and linearity) were calculated for each track and evaluated for indication of behavioral responses to turbine presence and operation. Fish tracks were grouped based on tidal cycle, current velocity, and swimming direction and were evaluated with respect to turbine presence and operation and with respect to distance from the turbine. Nonparametric tests (Kolmogorov–Smirnov test) and multivariate analysis (canonical discriminant analysis) found significant differences among groups with respect to turbine presence and operation, suggesting that some fish responded to the turbine by adjusting swimming behavior, such as making small adjustments to swimming direction and velocity as they passed near the turbine. We found no evidence that fish were being struck by rotating blades, but there did appear to be large-scale avoidance initiated out of the range of the hydroacoustics detection system. Furthermore, more study is needed to determine whether such avoidance behavior has significant ramifications for normal fish movement patterns, bioenergetics, seasonal migrations, and predator exposure.« less

Hydroacoustic Assessment of Behavioral Responses by Fish Passing Near an Operating Tidal Turbine in the East River, New York

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

Bevelhimer, Mark; Scherelis, Constantin C.; Colby, Jonathan

An important environmental issue facing the marine and hydrokinetic energy industry is whether fish that encounter underwater energy devices are likely to be struck and injured by moving components, primarily rotating turbine blades. The automated analysis of nearly 3 weeks of multibeam hydroacoustics data identified about 35,000 tracks of fish passing a tidal turbine in the East River, New York. These tracks included both individual fish and schools during periods with the turbine absent, the turbine present and operating, and the turbine present but not operating. The density of fish in the sampled area when the turbine was absent wasmore » roughly twice the density observed when the turbine was in place, particularly when the turbine was operating. This suggests that some avoidance occurred before fish were close enough to the turbine to be observed by the hydroacoustics system. Various measures of swimming behavior (direction, velocity, and linearity) were calculated for each track and evaluated for indication of behavioral responses to turbine presence and operation. Fish tracks were grouped based on tidal cycle, current velocity, and swimming direction and were evaluated with respect to turbine presence and operation and with respect to distance from the turbine. Nonparametric tests (Kolmogorov–Smirnov test) and multivariate analysis (canonical discriminant analysis) found significant differences among groups with respect to turbine presence and operation, suggesting that some fish responded to the turbine by adjusting swimming behavior, such as making small adjustments to swimming direction and velocity as they passed near the turbine. We found no evidence that fish were being struck by rotating blades, but there did appear to be large-scale avoidance initiated out of the range of the hydroacoustics detection system. Furthermore, more study is needed to determine whether such avoidance behavior has significant ramifications for normal fish movement patterns, bioenergetics, seasonal migrations, and predator exposure.« less

The Psychometrics of the Mini-K.

PubMed

Richardson, George B; Chen, Ching-Chen; Dai, Chia-Liang; Brubaker, Michael D; Nedelec, Joseph L

2017-01-01

Many published studies have employed the Mini-K to measure a single fast-slow life history dimension. However, the internal structure of the Mini-K has not been determined and it is not clear that a single higher order K-factor fits the data. It is also not clear that the Mini-K is measurement invariant across groups such as the sexes. To establish the construct validity of K as well as the broader usefulness of applying life history theory to humans, it is crucial that these psychometric issues are addressed as a part of measure validation efforts. Here we report on three studies that used latent variable modeling and data drawn from two college student samples ( ns = 361 and 300) to elucidate the psychometrics of the Mini-K. We found that (a) the Mini-K had a six dimensional first-order structure, (b) the K-factor provided a parsimonious explanation of the associations among the lower order factors at no significant cost to fit, (c) the Mini-K measured the same K-factor across the sexes, (d) K-factor means did not have the same meaning across the sexes and thus the first-order factors should be used in studies of mean sex differences, and finally, (e) the K-factor was only associated with environment and aspects of mating competition in females. Implications and future directions for life history research are discussed.

Mu-driven transposition of recombinant mini-Mu unit DNA in the Corynebacterium glutamicum chromosome.

PubMed

Gorshkova, Natalya V; Lobanova, Juliya S; Tokmakova, Irina L; Smirnov, Sergey V; Akhverdyan, Valerii Z; Krylov, Alexander A; Mashko, Sergey V

2018-03-01

A dual-component Mu-transposition system was modified for the integration/amplification of genes in Corynebacterium. The system consists of two types of plasmids: (i) a non-replicative integrative plasmid that contains the transposing mini-Mu(LR) unit bracketed by the L/R Mu ends or the mini-Mu(LER) unit, which additionally contains the enhancer element, E, and (ii) an integration helper plasmid that expresses the transposition factor genes for MuA and MuB. Efficient transposition in the C. glutamicum chromosome (≈ 2 × 10 -4 per cell) occurred mainly through the replicative pathway via cointegrate formation followed by possible resolution. Optimizing the E location in the mini-Mu unit significantly increased the efficiency of Mu-driven intramolecular transposition-amplification in C. glutamicum as well as in gram-negative bacteria. The new C. glutamicum genome modification strategy that was developed allows the consequent independent integration/amplification/fixation of target genes at high copy numbers. After integration/amplification of the first mini-Mu(LER) unit in the C. glutamicum chromosome, the E-element, which is bracketed by lox-like sites, is excised by Cre-mediated fashion, thereby fixing the truncated mini-Mu(LR) unit in its position for the subsequent integration/amplification of new mini-Mu(LER) units. This strategy was demonstrated using the genes for the citrine and green fluorescent proteins, yECitrine and yEGFP, respectively.

Mini-implants for Orthodontic Anchorage: Surface Analysis after Redrilling and Sterilization - An in vitro Study.

PubMed

Gross, J M; Nascimento, G G; Araújo, V C; Bönecker, Mjs; Furuse, C

2016-04-01

This study aimed to investigate, in vitro, possible alterations on mini-implants surface after retrieval and if the cleaning process and sterilization can predispose damages. Two commercial mini-implants were tested for deformations after drilling and removing in artificial bone four times. Samples were analyzed by scanning electron microscopy, and surface alterations verified through thread and pitches deformation. To alterations caused by insertion/removal and the cleaning process and sterilization were verified in different procedures: Insertions and sterilization, only insertions, and only sterilization. Photomicrographs were analyzed in order to compare the surface characteristics. Head deformation was verified qualitatively. For a quantitative analysis, distances between threads were measured across the active part of the mini-implants. No deformation was observed in both groups. The cleaning and sterilization processes did not provoke alteration in both groups. Nevertheless, the presence of synthetic bone was noted in some samples. The mean distances between implant threads were similar after all steps in all regions in both groups. The results suggest that the tested mini-implants can be retrieved without damage of its surface after four cycles of insertion, removal, and sterilization. Orthodontic mini-implant, Redrilling, Sterilization. Mini-implants can be retrieved without damage to its surface after four cycles of insertion, removal, and sterilization in the same patient without representing a biological concern.

Congenital hypogonadotropic hypogonadism: implications of absent mini-puberty.

PubMed

Dwyer, Andrew A; Jayasena, Channa N; Quinton, Richard

2016-06-01

The phenomenon known as "mini-puberty" refers to activation of the neonatal hypothalamo-pituitary axis causing serum concentrations of gonadotrophins and testosterone (T) to approach adult male levels. This early neonatal period is a key proliferative window for testicular germ cells and immature Sertoli cells. Although failure to spontaneously initiate (adolescent) puberty is the most evident consequence of a defective gonadotropin-releasing hormone (GnRH) neurosecretory network, absent mini-puberty is also likely to have a major impact on the reproductive phenotype of men with congenital hypogonadotrophic hypogonadism (CHH). Furthermore, the phase of male mini-puberty represents a key window-of-opportunity to identify congenital GnRH deficiency (either isolated CHH, or as part of combined pituitary hormone deficiency) in childhood. Among male neonates exhibiting "red flag" indicators for CHH (i.e. maldescended testes with or without cryptorchidism) a single serum sample (between 4-8 weeks of life) can pinpoint congenital GnRH deficiency far more rapidly and with much greater accuracy than dynamic tests performed in later childhood or adolescence. Potential consequences for missing absent mini-puberty in a male neonate include the lack of monitoring of pubertal progression/lack of progression, and the missed opportunity for early therapeutic intervention. This article will review our current understanding of the mechanisms and clinical consequences of mini-puberty. Furthermore, evidence for the optimal clinical management of patients with absent mini-puberty will be discussed.

An anthropological approach to teach and evaluate cultural competence in medical students - the application of mini-ethnography in medical history taking.

PubMed

Hsieh, Jyh-Gang; Hsu, Mutsu; Wang, Ying-Wei

2016-01-01

Purpose To use mini-ethnographies narrating patient illness to improve the cultural competence of the medical students. Methods Between September 2013 and June 2015, all sixth-year medical students doing their internship at a medical center in eastern Taiwan were trained to write mini-ethnographies for one of the patients in their care. The mini-ethnographies were analyzed by authors with focus on the various aspects of cultural sensitivity and a holistic care approach. Results Ninety-one students handed in mini-ethnographies, of whom 56 were male (61.5%) and 35 were female (38.5%). From the mini-ethnographies, three core aspects were derived: 1) the explanatory models and perceptions of illness, 2) culture and health care, and 3) society, resources, and health care. Based on the qualities of each aspect, nine secondary nodes were classified: expectations and attitude about illness/treatment, perceptions about their own prognosis in particular, knowledge and feelings regarding illness, cause of illness, choice of treatment method (including traditional medical treatments), prejudice and discrimination, influences of traditional culture and language, social support and resources, and inequality in health care. Conclusions Mini-ethnography is an effective teaching method that can help students to develop cultural competence. It also serves as an effective instrument to assess the cultural competence of medical students.

Millwright Apprenticeship. Related Training Modules. 8.1-8.5 Turbines.

ERIC Educational Resources Information Center

Lane Community Coll., Eugene, OR.

This packet, part of the instructional materials for the Oregon apprenticeship program for millwright training, contains five modules covering turbines. The modules provide information on the following topics: types, components, and auxiliaries of steam turbines; operation and maintenance of steam turbines; and gas turbines. Each module consists…

14 CFR 27.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 27.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 27.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 29.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 29.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 29.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 29.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 27.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 27.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

14 CFR 29.939 - Turbine engine operating characteristics.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be... limitations of the rotorcraft and of the engine. (b) The turbine engine air inlet system may not, as a result...

Wind Turbine Research Validation | Wind | NREL

Science.gov Websites

Wind Turbine Research Validation Wind Turbine Research Validation Photo of a large wind turbine operators with turbine and component research validation that ensures performance and reliability. Prototype research is especially important to capture manufacturing flaws. The NWTC staff conducts research on

Development and Analysis of a Bi-Directional Tidal Turbine

DTIC Science & Technology

2012-03-01

commercial CFD software ANSYS CFX was utilized to build a turbine map. The basic turbine map was developed for a 25 blade bi-axial turbine under...directional turbine created for this purpose. In the present study, the commercial CFD software ANSYS CFX was utilized to build a turbine map. The...sheath C. PROBLEM SPECIFICATIONS AND BOUNDARY CONDITIONS The simulation definition was created using ANSYS CFX -Pre. The best measurements to determine

Development and Evaluation of Processes for Deposition of Ni/Co-Cr-Aly (MCrAly) Coatings for Gas Turbine Components.

DTIC Science & Technology

1979-09-01

turbine engines demand increasingly higher operating tem- peratures in blades and vanes for greater thrust and efficiency. The turbine components...limitations; namely, expense and the inability to uniformly coat complex geometries and clustered turbine blade and vane airfoils . Thus, another means of...cost and the ability to uniformly coat turbine components of complex geometries and clustered turbine blade and vane airfoils .

Turbulent Dispersion of Film Coolant and Hot Streaks in a Turbine Vane Cascade

DTIC Science & Technology

2015-01-18

of Film Coolant in a Turbine Vane Cascade, ASME 2014 International Gas Turbine Institute (10 2013) TOTAL: 1 Books Number of Manuscripts: Patents...Stanford, CA 94305 eatonj@stanford.edu (650) 723-1971 Overview High pressure turbine blades in gas turbine engines are exposed to extremely harsh...results are applicable to real gas turbines . The latter goal led to the development of a second experimental configuration that was not in the

Development turbine blade for ultramicro hydro power generation by 3D printer system

NASA Astrophysics Data System (ADS)

Kamimura, T.; Itoh, H.; Sugiura, K.

2017-11-01

We have developed micro generation system for effective use of unutilized energy and the spread of a self-controlled dispersion energy supply system. The turbine blade was designed for achieving high performance by special shape. The turbine type was called quasi-Peace turbine type. Turbine with a diameter of 30cm is made of metal, it was created by the 5-axis milling machine. The experimental apparatus was fabricated by the 3D printer. An experiment was carried out in the scale down model. The specific speed of this turbine was much lower than that of existing turbines.

Fuel quality/processing study. Volume 4: On site processing studies

NASA Technical Reports Server (NTRS)

Jones, G. E., Jr.; Cutrone, M.; Doering, H.; Hickey, J.

1981-01-01

Fuel treated at the turbine and the turbine exhaust gas processed at the turbine site are studied. Fuel treatments protect the turbine from contaminants or impurities either in the upgrading fuel as produced or picked up by the fuel during normal transportation. Exhaust gas treatments provide for the reduction of NOx and SOx to environmentally acceptable levels. The impact of fuel quality upon turbine maintenance and deterioration is considered. On site costs include not only the fuel treatment costs as such, but also incremental costs incurred by the turbine operator if a turbine fuel of low quality is not acceptably upgraded.

Methods of Si based ceramic components volatilization control in a gas turbine engine

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

Garcia-Crespo, Andres Jose; Delvaux, John; Dion Ouellet, Noemie

A method of controlling volatilization of silicon based components in a gas turbine engine includes measuring, estimating and/or predicting a variable related to operation of the gas turbine engine; correlating the variable to determine an amount of silicon to control volatilization of the silicon based components in the gas turbine engine; and injecting silicon into the gas turbine engine to control volatilization of the silicon based components. A gas turbine with a compressor, combustion system, turbine section and silicon injection system may be controlled by a controller that implements the control method.

Turbine repair process, repaired coating, and repaired turbine component

DOEpatents

Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

2015-11-03

A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

Performance characteristics of aerodynamically optimum turbines for wind energy generators

NASA Technical Reports Server (NTRS)

Rohrbach, C.; Worobel, R.

1975-01-01

This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.

Quantitative analysis of backflow of reversible pump-turbine in generating mode

NASA Astrophysics Data System (ADS)

Liu, K. H.; Zhang, Y. N.; Li, J. W.; Xian, H. Z.

2016-05-01

Significant vibration and pressure fluctuations are usually observed when pump- turbine is operated during the off-design conditions, especially turbine brake and runaway. The root cause of these instability phenomena is the abnormal unsteady flow (especially the backflow) inside the pump-turbine. In the present paper, numerical simulation method is adopted to investigate the characteristics of the flow inside the whole passage of pump-turbine with two guide vane openings (6° and 21° respectively) and three kinds of operating conditions (turbine, runaway and turbine braking respectively). A quantitative analysis of backflow is performed in both the axial and radial directions and the generation and development of backflow in the pump turbine are revealed with great details.

Cold-air performance of compressor-drive turbine of Department of Energy upgraded automobile gas turbine engine. 2: Stage performance

NASA Technical Reports Server (NTRS)

Roelke, R. J.; Haas, J. E.

1982-01-01

The aerodynamic performance of the compressor-drive turbine of the DOE upgraded gas turbine engine was determined in low temperature air. The as-received cast rotor blading had a significantly thicker profile than design and a fairly rough surface finish. Because of these blading imperfections a series of stage tests with modified rotors were made. These included the as-cast rotor, a reduced-roughness rotor, and a rotor with blades thinned to near design. Significant performance changes were measured. Tests were also made to determine the effect of Reynolds number on the turbine performance. Comparisons are made between this turbine and the compressor-drive turbine of the DOE baseline gas turbine engine.

Mean-line Modeling of an Axial Turbine

NASA Astrophysics Data System (ADS)

Tkachenko, A. Yu; Ostapyuk, Ya A.; Filinov, E. P.

2018-01-01

The article describes the approach for axial turbine modeling along the mean line. It bases on the developed model of an axial turbine blade row. This model is suitable for both nozzle vanes and rotor blades simulations. Consequently, it allows the simulation of the single axial turbine stage as well as a multistage turbine. The turbine stage model can take into account the cooling air flow before and after a throat of each blade row, outlet straightener vanes existence and stagger angle controlling of nozzle vanes. The axial turbine estimation method includes the loss estimation and thermogasdynamic analysis. The single stage axial turbine was calculated with the developed model. The obtained results deviation was within 3% when comparing with the results of CFD modeling.

Aircraft engine with inter-turbine engine frame supported counter rotating low pressure turbine rotors

NASA Technical Reports Server (NTRS)

Seda, Jorge F. (Inventor); Dunbar, Lawrence W. (Inventor); Gliebe, Philip R. (Inventor); Szucs, Peter N. (Inventor); Brauer, John C. (Inventor); Johnson, James E. (Inventor); Moniz, Thomas (Inventor); Steinmetz, Gregory T. (Inventor)

2003-01-01

An aircraft gas turbine engine assembly includes an inter-turbine frame axially located between high and low pressure turbines. Low pressure turbine has counter rotating low pressure inner and outer rotors with low pressure inner and outer shafts which are at least in part rotatably disposed co-axially within a high pressure rotor. Inter-turbine frame includes radially spaced apart radially outer first and inner second structural rings disposed co-axially about a centerline and connected by a plurality of circumferentially spaced apart struts. Forward and aft sump members having forward and aft central bores are fixedly joined to axially spaced apart forward and aft portions of the inter-turbine frame. Low pressure inner and outer rotors are rotatably supported by a second turbine frame bearing mounted in aft central bore of aft sump member. A mount for connecting the engine to an aircraft is located on first structural ring.

Effect of steam sterilization inside the turbine chambers of dental turbines.

PubMed

Andersen, H K; Fiehn, N E; Larsen, T

1999-02-01

It has been demonstrated that contamination of the insides of high-speed dental turbines occurs and that bacteria as well as viruses may remain infectious when expelled from such turbines during subsequent use. Consequently, it has been widely recommended that a high-speed turbine be sterilized after each patient. The purpose of this study was to evaluate the effect of steam autoclaving on a high-speed dental turbine with a contaminated turbine chamber. Streptococcus salivarius and endospores of Bacillus stearothermophilus were used as test organisms to determine the effectiveness of 4 different small non-vacuum autoclaves and one vacuum autoclave. The study demonstrated different efficiencies among the small non-vacuum autoclaves, the best showing close to a 6 log reduction of the test organisms inside the turbine chamber. When cleaning and lubrication of the high-speed dental turbine was carried out before autoclaving, this level of reduction was observed for all the examined non-vacuum autoclaves. It is concluded that cleaning before sterilization is essential for safe use of high-speed dental turbines and that small non-vacuum autoclaves should be carefully evaluated before being used for the reprocessing of hollow instruments such as high-speed turbines.

Numerical simulation of turbulence flow in a Kaplan turbine -Evaluation on turbine performance prediction accuracy-

NASA Astrophysics Data System (ADS)

Ko, P.; Kurosawa, S.

2014-03-01

The understanding and accurate prediction of the flow behaviour related to cavitation and pressure fluctuation in a Kaplan turbine are important to the design work enhancing the turbine performance including the elongation of the operation life span and the improvement of turbine efficiency. In this paper, high accuracy turbine and cavitation performance prediction method based on entire flow passage for a Kaplan turbine is presented and evaluated. Two-phase flow field is predicted by solving Reynolds-Averaged Navier-Stokes equations expressed by volume of fluid method tracking the free surface and combined with Reynolds Stress model. The growth and collapse of cavitation bubbles are modelled by the modified Rayleigh-Plesset equation. The prediction accuracy is evaluated by comparing with the model test results of Ns 400 Kaplan model turbine. As a result that the experimentally measured data including turbine efficiency, cavitation performance, and pressure fluctuation are accurately predicted. Furthermore, the cavitation occurrence on the runner blade surface and the influence to the hydraulic loss of the flow passage are discussed. Evaluated prediction method for the turbine flow and performance is introduced to facilitate the future design and research works on Kaplan type turbine.

Advanced turbine study. [airfoil coling in rocket turbines

NASA Technical Reports Server (NTRS)

1982-01-01

Experiments to determine the available increase in turbine horsepower achieved by increasing turbine inlet temperature over a range of 1800 to 2600 R, while applying current gas turbine airfoil cling technology are discussed. Four cases of rocket turbine operating conditions were investigated. Two of the cases used O2/H2 propellant, one with a fuel flowrate of 160 pps, the other 80 pps. Two cases used O2/CH4 propellant, each having different fuel flowrates, pressure ratios, and inlet pressures. Film cooling was found to be the required scheme for these rocket turbine applications because of the high heat flux environments. Conventional convective or impingement cooling, used in jet engines, is inadequate in a rocket turbine environment because of the resulting high temperature gradients in the airfoil wall, causing high strains and low cyclic life. The hydrogen-rich turbine environment experienced a loss, or no gain, in delivered horsepower as turbine inlet temperature was increased at constant airfoil life. The effects of film cooling with regard to reduced flow available for turbine work, dilution of mainstream gas temperature and cooling reentry losses, offset the relatively low specific work capability of hydrogen when increasing turbine inlet temperature over the 1800 to 2600 R range. However, the methane-rich environment experienced an increase in delivered horsepower as turbine inlet temperature was increased at constant airfoil life. The results of a materials survey and heat transfer and durability analysis are discussed.

Assessing hydraulic conditions through Francis turbines using an autonomous sensor device

DOE PAGES

Fu, Tao; Deng, Zhiqun Daniel; Duncan, Joanne P.; ...

2016-08-19

Downstream migratory fish, including some endangered species, can be injured or killed during turbine passage. In this study an autonomous Sensor Fish device was deployed at Arrowrock Dam, Cougar Dam, and Detroit Dam to evaluate the hydraulic conditions and physical stresses that fish experienced when passing through these Francis turbines. Pressure data was used to identify the location of the Sensor Fish and to calculate the nadir pressure and the magnitude and the rate of change in pressure during turbine passage. Acceleration data was used to identify events (collisions or shear) Sensor Fish experienced and to categorize the severity levelmore » (severe, medium, and slight) of each event. The results showed that Sensor Fish experienced severe events mostly in the stay vane/wicket gate region and the runner region. In the stay vane/wicket gate region, almost all severe events were collisions. In the runner region, Sensor fish experienced both severe collisions and severe shear events. Sensor Fish data at three wicket gate opening treatments at Cougar Dam indicated that the wicket gate opening of the Francis turbine can affect the hydraulic conditions in the turbine runner region. Fewer Sensor Fish experienced severe collisions in the turbine runner region at the peak efficiency than at the minimum opening and the maximum opening treatments. Comparisons between the Francis turbines at the three dams and the AHT Kaplan turbine at Wanapum Dam showed that higher percentage of Sensor Fish experienced severe events in the runner region when passing through Francis turbines than the AHT Kaplan turbine. The nadir pressures of the Francis turbines were lower than those of the AHT Kaplan turbine at Wanapum Dam. Both the magnitude and the rate of change in pressure were higher in Francis turbines than in the AHT Kaplan turbine at Wanapum Dam in the runner region. This study can be used to guide future laboratory studies of fish passing through Francis turbine and help the design of more fish-friendly turbines for new hydroelectric dams or the rehabilitations of existing dams.« less

Cross-flow turbines: physical and numerical model studies towards improved array simulations

NASA Astrophysics Data System (ADS)

Wosnik, M.; Bachant, P.

2015-12-01

Cross-flow, or vertical-axis turbines, show potential in marine hydrokinetic (MHK) and wind energy applications. As turbine designs mature, the research focus is shifting from individual devices towards improving turbine array layouts for maximizing overall power output, i.e., minimizing wake interference for axial-flow turbines, or taking advantage of constructive wake interaction for cross-flow turbines. Numerical simulations are generally better suited to explore the turbine array design parameter space, as physical model studies of large arrays at large model scale would be expensive. However, since the computing power available today is not sufficient to conduct simulations of the flow in and around large arrays of turbines with fully resolved turbine geometries, the turbines' interaction with the energy resource needs to be parameterized, or modeled. Most models in use today, e.g. actuator disk, are not able to predict the unique wake structure generated by cross-flow turbines. Experiments were carried out using a high-resolution turbine test bed in a large cross-section tow tank, designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. To improve parameterization in array simulations, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier--Stokes models. The ALM predicts turbine loading with the blade element method combined with sub-models for dynamic stall and flow curvature. The open-source software is written as an extension library for the OpenFOAM CFD package, which allows the ALM body force to be applied to their standard RANS and LES solvers. Turbine forcing is also applied to volume of fluid (VOF) models, e.g., for predicting free surface effects on submerged MHK devices. An additional sub-model is considered for injecting turbulence model scalar quantities based on actuator line element loading. Results are presented for the simulation of performance and wake dynamics of axial- and cross-flow turbines and compared with experiments and body-fitted mesh, blade-resolving CFD. Supported by NSF-CBET grant 1150797.

Physical and Numerical Model Studies of Cross-flow Turbines Towards Accurate Parameterization in Array Simulations

NASA Astrophysics Data System (ADS)

Wosnik, M.; Bachant, P.

2014-12-01

Cross-flow turbines, often referred to as vertical-axis turbines, show potential for success in marine hydrokinetic (MHK) and wind energy applications, ranging from small- to utility-scale installations in tidal/ocean currents and offshore wind. As turbine designs mature, the research focus is shifting from individual devices to the optimization of turbine arrays. It would be expensive and time-consuming to conduct physical model studies of large arrays at large model scales (to achieve sufficiently high Reynolds numbers), and hence numerical techniques are generally better suited to explore the array design parameter space. However, since the computing power available today is not sufficient to conduct simulations of the flow in and around large arrays of turbines with fully resolved turbine geometries (e.g., grid resolution into the viscous sublayer on turbine blades), the turbines' interaction with the energy resource (water current or wind) needs to be parameterized, or modeled. Models used today--a common model is the actuator disk concept--are not able to predict the unique wake structure generated by cross-flow turbines. This wake structure has been shown to create "constructive" interference in some cases, improving turbine performance in array configurations, in contrast with axial-flow, or horizontal axis devices. Towards a more accurate parameterization of cross-flow turbines, an extensive experimental study was carried out using a high-resolution turbine test bed with wake measurement capability in a large cross-section tow tank. The experimental results were then "interpolated" using high-fidelity Navier--Stokes simulations, to gain insight into the turbine's near-wake. The study was designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. The end product of this work will be a cross-flow turbine actuator line model to be used as an extension to the OpenFOAM computational fluid dynamics (CFD) software framework, which will likely require modifications to commonly-used dynamic stall models, in consideration of the turbines' high angle of attack excursions during normal operation.

Assessing hydraulic conditions through Francis turbines using an autonomous sensor device

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

Fu, Tao; Deng, Zhiqun Daniel; Duncan, Joanne P.

Downstream migratory fish, including some endangered species, can be injured or killed during turbine passage. In this study an autonomous Sensor Fish device was deployed at Arrowrock Dam, Cougar Dam, and Detroit Dam to evaluate the hydraulic conditions and physical stresses that fish experienced when passing through these Francis turbines. Pressure data was used to identify the location of the Sensor Fish and to calculate the nadir pressure and the magnitude and the rate of change in pressure during turbine passage. Acceleration data was used to identify events (collisions or shear) Sensor Fish experienced and to categorize the severity levelmore » (severe, medium, and slight) of each event. The results showed that Sensor Fish experienced severe events mostly in the stay vane/wicket gate region and the runner region. In the stay vane/wicket gate region, almost all severe events were collisions. In the runner region, Sensor fish experienced both severe collisions and severe shear events. Sensor Fish data at three wicket gate opening treatments at Cougar Dam indicated that the wicket gate opening of the Francis turbine can affect the hydraulic conditions in the turbine runner region. Fewer Sensor Fish experienced severe collisions in the turbine runner region at the peak efficiency than at the minimum opening and the maximum opening treatments. Comparisons between the Francis turbines at the three dams and the AHT Kaplan turbine at Wanapum Dam showed that higher percentage of Sensor Fish experienced severe events in the runner region when passing through Francis turbines than the AHT Kaplan turbine. The nadir pressures of the Francis turbines were lower than those of the AHT Kaplan turbine at Wanapum Dam. Both the magnitude and the rate of change in pressure were higher in Francis turbines than in the AHT Kaplan turbine at Wanapum Dam in the runner region. This study can be used to guide future laboratory studies of fish passing through Francis turbine and help the design of more fish-friendly turbines for new hydroelectric dams or the rehabilitations of existing dams.« less

Research for the Classroom: Mini Vocabulary Lessons for Maximum Recall

ERIC Educational Resources Information Center

Sovereen, Deanne

2013-01-01

"Research for the Classroom" publishes mini-studies of ELA classroom practices and suggests ways in which high school and middle school English teachers may study the effectiveness of their pedagogy. The author of this mini-study notes that it takes around six minutes per day of instructional time for students to remember most of the…

Mini-Versus Traditional: An Experimental Study of High School Social Studies Curricula.

ERIC Educational Resources Information Center

Roberts, Arthur D.; Gable, Robert K.

This study assessed some of the cognitive and affective elements for both the traditional and mini curricula. The hypothesis, stated in the null form, was there will be no difference between students in the mini-course curriculum and the traditional curriculum on a number of stated cognitive variables (focusing on critical thinking and reading…

Propulsion and power for 21st century aviation

NASA Astrophysics Data System (ADS)

Sehra, Arun K.; Whitlow, Woodrow

2004-05-01

Air transportation in the new millennium will require revolutionary solutions to meet public demand for improving safety, reliability, environmental compatibility, and affordability. NASA's vision for 21st century aircraft is to develop propulsion systems that are intelligent, highly efficient, virtually inaudible (outside airport boundaries), and have near zero harmful emissions (CO 2 and NO x). This vision includes intelligent engines capable of adapting to changing internal and external conditions to optimally accomplish missions with either minimal or no human intervention. Distributed vectored propulsion will replace current two to four wing mounted and fuselage mounted engine configurations with a large number of small, mini, or micro engines. Other innovative concepts, such as the pulse detonation engine (PDE), which potentially can replace conventional gas turbine engines, also are reviewed. It is envisioned that a hydrogen economy will drive the propulsion system revolution towards the ultimate goal of silent aircrafts with zero harmful emissions. Finally, it is envisioned that electric drive propulsion based on fuel cell power will generate electric power, which in turn will drive propulsors to produce the desired thrust. This paper reviews future propulsion and power concepts that are under development at the National Aeronautics and Space Administration's (NASA) John H. Glenn Research Center at Lewis Field, Cleveland, Ohio, USA.

The clinical and radiological results of arthroscopic versus arthroscopy assisted mini-open repair of rotator cuff tears

PubMed Central

Özcan, Muhammed Sefa; Sezer, Hasan Basri; Eren, Osman Tuğrul; Armağan, Raffi; Kanar, Muharrem

2017-01-01

In this study we reported retrospectively the comperative clinical and radiological results of the two most common surgical procedures in rotator cuff tear repair of shoulder, the golden standart arthroscopic and alternative arthroscopically assisted mini-open surgery. We included 58 patients who admitted to our clinic for rotator cuff tear and treated surgically between january 2013 and august 2015. The two groups were composed of arthroscopically treated 29 patients and 29 patients who were treated with arthroscopically assisted mini open surgery. The arthroscopy group included 18 females and 11 males, the mini-open group included 10 females and 19 males. The mean age was 56,0 (39,0-73,0) years, in arthroscopic and 55,0 (40,0-70,0) years in mini-open surgery group. 6 patients in the arthroscopy group(20,7%) and 10 patients in the mini-open group(34,5%) were defining trauma before the beginning of their complaints. The postoperative follow up was 28,9 months in arthroscopy group and 22,6 months in the mini-open surgery group. Preoperative physical or medical treatments were documented. Any additional surgical procedures like biceps long head tenotomy, subacromial decompression and bursectomy were also noted. Patients were evaluated with ASES and Constant shoulder scales before and after the surgery. Patients were evaluated radiologically with MRI at the last follow up for healing and tendon quality. The type 2 acromion was the dominant in both groups constituting the 44,8% of the total number of patients. 24 (82,8%)patients in the arthroscopically treated patients and 18(62,1%) patients in the mini-open group were undergone at least one of the additional surgical treatments. The mean length of the surgical scar was 3,4(3-5) cm in mini open group. None of the patients complained of the surgical scar. 16 patients in the arthroscopy group and 17 patients in the mini-open group had supraspinatus tendon pathology(either tear or degeneration) in the MRI control at the last follow up. Postoperative pain was present in 1 patient in each group who were classified as bad result. There was no statistically meaningful difference between two groups in terms of clinical or radiological results. In conclusion the arthroscopy assisted mini-open surgery may be a useful tool in hands of training surgeons to prevent ineffective treatment of rotator cuff tears.

Evaluating depressive symptoms in hypomanic and manic episodes using a structured diagnostic tool: validation of a new Mini International Neuropsychiatric Interview (M.I.N.I.) module for the DSM-5 'With Mixed Features' specifier.

PubMed

Hergueta, Thierry; Weiller, Emmanuelle

2013-01-01

The Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), includes a new 'With Mixed Features' specifier for mood episodes. In (hypo-)manic episodes, the specifier is given if three or more depressive symptoms are present nearly every day during the episode. A new module of the Mini International Neuropsychiatric Interview (M.I.N.I.) has been developed as a patient-completed questionnaire to evaluate the DSM-5 specifier for (hypo-)manic episodes. The objective of this study was to validate this new module. In Phase I, patients with a manic episode in the past 6 months completed the module and were asked whether the wording was clear, understandable, relevant and specific. Based on their feedback, the module was refined and finalised. In Phase II, psychiatrists each invited five patients to complete the module. The psychiatrists completed record forms for these five patients, which included their diagnoses, made according to DSM-5 criteria during clinical interviewing. The module was validated by comparing depressive symptoms reported by the patients themselves using the M.I.N.I. module with those evaluated by their psychiatrist using DSM-5 criteria during clinical interviewing. In Phase I, a few changes were made to the M.I.N.I. module based on feedback from 20 patients (60% of whom had mixed features). In Phase II, 23 psychiatrists completed record forms for 115 patients, 99 (86.1%) of whom completed the M.I.N.I. module. Agreement between psychiatrists' DSM-5 diagnoses and patients' M.I.N.I. responses was substantial (Cohen's kappa coefficient, 0.60). The overall sensitivity of the M.I.N.I. was 0.91 and its specificity was 0.70. Sensitivity ranged from 0.63 for psychomotor retardation to 0.90 for suicidal thoughts. Specificity ranged from 0.63 for diminished interest/pleasure to 0.90 for suicidal thoughts. The module's positive and negative predictive values were 0.72 and 0.90, respectively. In summary, the M.I.N.I. module demonstrated good concurrent validity with psychiatrists' evaluation of DSM-5 mixed features in manic patients, accurately detecting mixed features with limited risk of over-diagnosis. Due to its simplicity, the M.I.N.I. module could be incorporated into routine psychiatric evaluation of patients with manic episodes. It could also provide a valuable standardised tool for clinical and epidemiological research.

Late-stage development of the Bryant Canyon turbidite pathway on the Louisiana continental slope

USGS Publications Warehouse

Twichell, David C.; Nelson, Hans; Damuth, John E.

2000-01-01

GLORIA sidescan imagery, multibeam bathymetry, seismic profiles, and piston cores (3–5 m penetration) reveal the near-surface geology of the Bryant Canyon turbidite pathway on the continental margin of Louisiana. This pathway extends from the continental shelf edge, across the continental slope, to a deep-sea fan on the continental rise. The pathway is narrow (<2 km) where it crosses shallow salt deposits. Turbidites have been sampled from these narrow segments, and radiocarbon dates indicate that some of them accumulated as recently as 10,150 yr B.P. The pathway broadens however, where it crosses mini-basins whose floors are covered largely by muddy mass-transport deposits and coarse silt turbidites. Mass-transport deposits in the upper 4.7 m of cores from the floors of mini-basins accumulated 18,140-3,400 yr. BP. Seismic profiles show that the mass-transport deposits in some of the mini-basins are as much as 225 milliseconds thick and that turbidites in the basin floor are buried by these deposits. Salt movement has had a major impact on this pathway, and its thalweg no longer has a continuous down-slope gradient. Some mini-basin floors along the pathway are now more than 500 m deeper than their basin’s spill point. We propose a 6-stage conceptual model to explain our observations for the evolution of a mini-basin along this turbidite pathway. In this model, an active channel feeds sand to a mini-basin (Stabe B). Once the mini-basin is filled, the sand deposit is entrenched by a bypass channel (Stage C). When the turbidite system shuts off, salt migration oversteepens the mini-basin walls (Stage D) which collapse and create a layer of mass-transport deposits on the mini-basin floor (Stage E). The depositional succession is capped by a layer of highstand hemipelagic drape (Stage F). The Bryant Canyon turbidite pathway provides a recent example of a large turbidite pathway in the Gulf of Mexico that crosses an area of active salt tectonics thus providing a conceptual model for older systems in similar settings. In Bryant Canyon, thick turbidite sands presumably are found in mini-basins however, they are sealed by thick, fine-grained, mass-transport deposits which terminate mini-basin turbidite deposition cycles. The importance of mass-transport deposits in basins along this turbidite pathway is in startling contrast to the Trinity-Brazos pathway whose shallow subsurface expression is virtually free of mass-transport deposits and has undergone minimal deformation by salt movement.

Implementing the undergraduate mini-CEX: a tailored approach at Southampton University.

PubMed

Hill, Faith; Kendall, Kathleen; Galbraith, Kevin; Crossley, Jim

2009-04-01

The mini-clinical evaluation exercise (mini-CEX) is widely used in the UK to assess clinical competence, but there is little evidence regarding its implementation in the undergraduate setting. This study aimed to estimate the validity and reliability of the undergraduate mini-CEX and discuss the challenges involved in its implementation. A total of 3499 mini-CEX forms were completed. Validity was assessed by estimating associations between mini-CEX score and a number of external variables, examining the internal structure of the instrument, checking competency domain response rates and profiles against expectations, and by qualitative evaluation of stakeholder interviews. Reliability was evaluated by overall reliability coefficient (R), estimation of the standard error of measurement (SEM), and from stakeholders' perceptions. Variance component analysis examined the contribution of relevant factors to students' scores. Validity was threatened by various confounding variables, including: examiner status; case complexity; attachment specialty; patient gender, and case focus. Factor analysis suggested that competency domains reflect a single latent variable. Maximum reliability can be achieved by aggregating scores over 15 encounters (R = 0.73; 95% confidence interval [CI] +/- 0.28 based on a 6-point assessment scale). Examiner stringency contributed 29% of score variation and student attachment aptitude 13%. Stakeholder interviews revealed staff development needs but the majority perceived the mini-CEX as more reliable and valid than the previous long case. The mini-CEX has good overall utility for assessing aspects of the clinical encounter in an undergraduate setting. Strengths include fidelity, wide sampling, perceived validity, and formative observation and feedback. Reliability is limited by variable examiner stringency, and validity by confounding variables, but these should be viewed within the context of overall assessment strategies.

Identification of Bacteriophage N4 Virion RNA Polymerase-Nucleic Acid Interactions in Transcription Complexes*

PubMed Central

Davydova, Elena K.; Kaganman, Irene; Kazmierczak, Krystyna M.; Rothman-Denes, Lucia B.

2009-01-01

Bacteriophage N4 mini-virion RNA polymerase (mini-vRNAP), the 1106-amino acid transcriptionally active domain of vRNAP, recognizes single-stranded DNA template-containing promoters composed of conserved sequences and a 3-base loop–5-base pair stem hairpin structure. The major promoter recognition determinants are a purine located at the center of the hairpin loop (–11G) and a base at the hairpin stem (–8G). Mini-vRNAP is an evolutionarily highly diverged member of the T7 family of RNAPs. A two-plasmid system was developed to measure the in vivo activity of mutant mini-vRNAP enzymes. Five mini-vRNAP derivatives, each containing a pair of cysteine residues separated by ∼100 amino acids and single cysteine-containing enzymes, were generated. These reagents were used to determine the smallest catalytically active polypeptide and to map promoter, substrate, and RNA-DNA hybrid contact sites to single amino acid residues in the enzyme by using end-labeled 5-iododeoxyuridine- and azidophenacyl-substituted oligonucleotides, cross-linkable derivatives of the initiating nucleotide, and RNA products with 5-iodouridine incorporated at specific positions. Localization of functionally important amino acid residues in the recently determined crystal structures of apomini-vRNAP and the mini-vRNAP-promoter complex and comparison with the crystal structures of the T7 RNAP initiation and elongation complexes allowed us to predict major rearrangements in mini-vRNAP in the transition from transcription initiation to elongation similar to those observed in T7 RNAP, a task otherwise precluded by the lack of sequence homology between N4 mini-vRNAP and T7 RNAP. PMID:19015264

MD-miniRNA could be a more accurate biomarker for prostate cancer screening compared with serum prostate-specific antigen level.

PubMed

Xue, Dong; Zhou, Cui-Xing; Shi, Yun-Bo; Lu, Hao; He, Xiao-Zhou

2015-05-01

Prostate cancer and prostatic hyperplasia detection remains a great challenge, lacking of effective non-invasive and specific diagnostic biomarkers. In the current study, we aimed to identify the relative expression of plasma MD-miniRNA and its diagnostic performance in differentiating prostate cancer and prostatic hyperplasia patients from healthy controls, compared with serum prostate-specific antigen (PSA) level. All of the clinical participants (63 prostate cancer patients, 32 prostatic hyperplasia patients, and 50 healthy controls) were obtained from the Third Affiliated Hospital of Suzhou University in China between January 2013 and April 2014. Clinical characteristics were well matched. Plasma samples were extracted to test the relative expression of MD-miniRNA using the method of qRT-PCR. SPSS 22.0 statistical software package was used to analyze the data and GraphPad Prism 6.0 was used to generate the graphs. Relativity expression of plasma MD-miniRNA was significantly upregulated in prostate cancer, compared with prostatic hyperplasia patients and healthy controls. Serum PSA level revealed similar differences among these groups. MD-miniRNA presented a relatively high diagnostic accuracy with AUC of 0.86 (95 % CI 0.80-0.93) in differentiating prostate cancer patients from healthy controls. Simultaneously, MD-miniRNA was able to discriminate prostate cancer patients from prostatic hyperplasia controls with AUC of 0.79 (95 % CI 0.70-0.88). In addition, MD-miniRNA displayed a better diagnostic performance than PSA level. However, the panel of these two biomarkers revealed the best diagnostic performance, compared with either single biomarker. Results of this study showed that plasma MD-miniRNA could serve as a promising and noninvasive biomarker for diagnosing prostate cancer. Further large-scale studies are needed to confirm its clinical diagnosis accuracy.

Mini-interfacial Fracture Toughness of a Multimode Adhesive Bonded to Plasma-treated Dentin.

PubMed

Ayres, Ana Paula Almeida; Pongprueksa, Pong; De Munck, Jan; Gré, Cristina Parise; Nascimento, Fábio Dupart; Giannini, Marcelo; Van Meerbeek, Bart

2017-01-01

To investigate the bonding efficacy of a multimode adhesive to plasma-treated and -untreated (control) dentin using a mini-interfacial fracture toughness (mini-iFT) test. Twenty human molars were used in a split-tooth design (n = 10). The adhesive Scotchbond Universal (SBU; 3M ESPE) was applied in etch-and-rinse (E&R) and self-etch (SE) modes. Mid-coronal dentin was exposed and covered with a standardized smear layer ground to 320 grit. One half of each dentin surface received 15 s of non-thermal atmospheric plasma (NTAP), while the other half was covered with a metallic barrier and kept untreated. Following the E&R mode, dentin was plasma treated immediately after phosphoric acid etching. SBU and a resin-based composite were applied to dentin following the manufacturer's instructions. Six mini-iFT specimens were prepared per tooth (1.5 x 2.0 x 16 to 18 mm), and a single notch was prepared at the adhesive-dentin interface using a 150-μm diamond blade under water cooling. Half of the mini-iFT specimens were immediately loaded until failure in a 4-point bending test, while the other half were first stored in distilled water for 6 months. After testing, the exact dimensions of the notch were measured with a measuring optical microscope, from which ΚIc was determined. Three-way ANOVA revealed higher mini-iFT for SBU applied in E&R than SE mode for both storage times, irrespective of NTAP treatment. Overall, mini-iFT did not decrease for any of the experimental groups upon 6-month aging, while plasma treatment did not show a direct beneficial effect on mini-iFT of SBU applied in either E&R or SE mode.

Evaluation of the success and complication rates of self-drilling orthodontic mini-implants.

PubMed

Gurdan, Z; Szalma, J

2018-05-01

Orthodontic mini-implants are important devices for successful anchorage management in orthodontics; however, the survival of these devices depends on several clinical factors. The aim of our study was to calculate the success and complication rates of orthodontic mini-implants. In this retrospective study, patients of our orthodontic department were enrolled, getting overall 59 orthodontic mini-implants during their orthodontic treatment in a 2-year period. Every patient had one or more of the 1.6 mm × 8 mm in size self-drilling mini-implants (Jeil Dual Top Anchor System, Jeil Medical Corp., Seoul, Korea). Screw loading was performed immediately after insertions, keeping tension forces under 150 g. Soft tissue and bone infections, implant mobility and screw loss, implant fracture, and neighboring tooth injury were registered. Relationships between variables were tested using the Chi-square test for statistical significance. The success rate of the orthodontic mini-implants was 89.8% in this study while the average loading period was 8.1 months. Soft-tissue infections varied between 6.3% and 33.3% of the cases while screw mobility varied between 3.1% and 20.8% of the cases regarding the anatomic localization. Screw mobility was significantly more frequent in the buccal fold than in the palate (P = 0.034). Screw mobility was significantly more frequent in the buccal fold than in the palate (P = 0.034) and screw mobility was found more frequently in case of intrusions than by extrusions (P = 0.036). The overall success rate of mini-implants was found acceptable in this study, however, screw mobility in the buccal fold showed a high incidence, suggesting the thorough consideration of the immediate loading by buccal mini-implants.

Validation of an electronic version of the Mini Asthma Quality of Life Questionnaire.

PubMed

Olajos-Clow, J; Minard, J; Szpiro, K; Juniper, E F; Turcotte, S; Jiang, X; Jenkins, B; Lougheed, M D

2010-05-01

The Mini Asthma Quality of Life Questionnaire (MiniAQLQ) is a validated disease-specific quality of life (QOL) paper (p) questionnaire. Electronic (e) versions enable inclusion of asthma QOL in electronic medical records and research databases. To validate an e-version of the MiniAQLQ, compare time required for completion of e- and p-versions, and determine which version participants prefer. Adults with stable asthma were randomized to complete either the e- or p-MiniAQLQ, followed by a 2-h rest period before completing the other version. Agreement between versions was measured using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Two participants with incomplete p-MiniAQLQ responses were excluded. Forty participants (85% female; age 47.7 +/- 14.9 years; asthma duration 22.6 +/- 16.1 years; FEV(1) 87.1 +/- 21.6% predicted) with both AQLQ scores <6.0 completed the study. Agreement between e- and p-versions for the overall score was acceptable (ICC=0.95) with no bias (difference (Delta) p-e=0.1; P=0.21). ICCs for the symptom, activity limitation, emotional function and environmental stimuli domains were 0.94, 0.89, 0.90, and 0.91 respectively. A small but significant bias (Delta=0.3; P=0.004) was noted in the activity limitation domain. Completion time was significantly longer for the e-version (3.8 +/- 1.9min versus 2.7 +/- 1.1min; P<0.0001). The majority of patients (57.5%) preferred the e-MiniAQLQ; 35% had no preference. This e-version of the MiniAQLQ is valid and was preferred by most participants despite taking slightly longer to complete. Generalizabilty may be limited in younger (12-17) and older (>65) adults.

A stainless steel bracket for orthodontic application.

PubMed

Oh, Keun-Taek; Choo, Sung-Uk; Kim, Kwang-Mahn; Kim, Kyoung-Nam

2005-06-01

Aesthetics has become an essential element when choosing orthodontic fixed appliances. Most metallic brackets used in orthodontic therapy are made from stainless steel (SS) with the appropriate physical properties and good corrosion resistance, and are available as types 304, 316 and 17-4 PH SS. However, localized corrosion of these materials can frequently occur in the oral environment. This study was undertaken to evaluate the accuracy of sizing, microstructure, hardness, corrosion resistance, frictional resistance and cytotoxicity of commercially available Mini-diamond (S17400), Archist (S30403) and experimentally manufactured SR-50A (S32050) brackets. The size accuracy of Mini-diamond was the highest at all locations except for the external horizontal width of the tie wing (P < 0.05). Micrographs of the Mini-diamond and Archist showed precipitates in the grains and around their boundaries. SR-50A showed the only austenitic phase and the highest polarization resistance of the tested samples. SR-50A also had the highest corrosion resistance [SR-50A, Mini-diamond and Archist were 0.9 x 10(-3), 3.7 x 10(-3), and 7.4 x 10(-3) mm per year (mpy), respectively], in the artificial saliva. The frictional force of SR-50A decreased over time, but that of Mini-diamond and Archist increased. Therefore, SR-50A is believed to have better frictional properties to orthodontic wire than Mini-diamond and Archist. Cytotoxic results showed that the response index of SR-50A was 0/1 (mild), Mini-diamond 1/1 (mild+), and Archist 1/2 (mild+). SR-50A showed greater biocompatibility than either Mini-diamond or Archist. It is concluded that the SR-50A bracket has good frictional property, corrosion resistance and biocompatibility with a lower probability of allergic reaction, compared with conventionally used SS brackets.

Poster - 23: Dosimetric Characterization and Transferability of an Accessory Mounted Mini-Beam Collimator

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

Davis, William; Crewson, Cody; Alexander, Andrew

Objective: The dosimetric characterization of an accessory-mounted mini-beam collimator across three beam matched linear accelerators. Materials and Methods: Percent depth dose and profiles were measured for the open and mini-beam collimated fields. The average beam quality and peak-to-valley dose ratio (PVDR), the ratio of average peak dose to average valley dose, were obtained from these measurements. The open field relative output and the mini-beam collimator factor, the ratio of the mini-beam dose to open field dose at the beam center, were measured for square fields of side 2, 3, 4, and 5 cm. Mini-beam output as a function of collimatormore » inclination angle relative to the central axis was also investigated. Results and Discussion: Beam quality for both the open and mini-beam collimated fields agreed across all linacs to within ±1.0%. The PVDR was found to vary by up to ±6.6% from the mean. For the 2, 3, and 4 cm fields the average open field relative output with respect to the 5 cm field was 0.874±0.4%, 0.921±0.3%, and 0.962±0.1%. The average collimator factors were 0.450±3.9%, 0.443±3.9%, 0.438±3.9%, and 0.434±3.9%. A decrease in collimator factor greater than 7% was found for an inclination angle change of 0.09°. Conclusion: The mini-beam collimator has revealed a difference between the three linacs not apparent in the open field data, yet transferability can still be attained through thorough dosimetric characterization.« less

Identifying applicants suitable to a career in nursing: a value-based approach to undergraduate selection.

PubMed

Traynor, Marian; Galanouli, Despina; Roberts, Martin; Leonard, Lawrence; Gale, Thomas

2017-06-01

The aim of this study was to complement existing evidence on the suitability of Multiple Mini Interviews as a potential tool for the selection of nursing candidates on to a BSc (Hons) nursing programme. This study aimed to trial the Multiple Mini Interview approach to recruitment with a group of first year nursing students (already selected using traditional interviews). Cross-sectional validation study. This paper reports on the evaluation of the participants' detailed scores from the Multiple Mini Interview stations; their original interview scores and their end of year results. This study took place in March 2015. Scores from the seven Multiple Mini Interview stations were analysed to show the internal structure, reliability and generalizability of the stations. Original selection scores from interviews and in-course assessment were correlated with the MMI scores and variation by students' age, gender and disability status was explored. Reliability of the Multiple Mini Interview score was moderate (G = 0·52). The Multiple Mini Interview score provided better differentiation between more able students than did the original interview score but neither score was correlated with the module results. Multiple Mini Interview scores were positively associated with students' age but not their gender or disability status. The Multiple Mini Interview reported in this study offers a selection process that is based on the values and personal attributes regarded as desirable for a career in nursing and does not necessarily predict academic success. Its moderate reliability indicates the need for further improvement but it is capable of discriminating between candidates and shows little evidence of bias. © 2016 John Wiley & Sons Ltd.

[Development of new type plastics air turbine handpiece for dental use].

PubMed

Kusano, M

1989-06-01

The noise generated by the metal air turbine handpiece employed in dental practice is considerable and attended with predominant high frequency components. Therefore, investigation of the noise generation mechanism and development of a silent air turbine handpiece was only a matter of course. In addition, the metal air turbine hardpiece is comparatively heavy and its production cost is high. From this point of view as well, production of a light air turbine handpiece at low cost is also desirable. In order to overcome the objections to the metal air turbine handpiece, appropriate plastics materials were employed wherever possible. In this study, the number of revolutions, noise level, frequency analysis, start pressure and weight of newly produced plastics handpieces and metal handpieces were examined and compared. The following results were obtained: 1. The number of revolutions of single-nozzle type air turbine handpieces encased in plastics housings and fitted with metal turbine rotors was higher than that of all-metal air turbine handpieces. The noise level of the former tended to be lower. 2. The number of revolutions of multi-nozzle type air turbine handpieces encased in plastics housings and fitted with turbine rotors with plastics turbine blades was almost equal to that of similar metal handpieces, with the noise level tending to be lower. 3. In the case of handpieces fitted with turbine rotors with dynamic balance, the number of revolutions was high and the noise level was low. This indicated that dynamic balance was a factor affecting the number of revolutions and noise level. 4. Narrow band sound frequency analysis of single-nozzle type air turbine handpieces showed a sharp peak at the fundamental frequency which was the same as the number of revolutions multiplied by the number of rotor turbine blades. It is thought that the noise from air turbine handpieces was aerodynamic in origin, being generated by the periodical interruption of steady air flow by rotor turbine blades. 5. The start pressure of plastics handpieces was almost equal to that of metal handpieces. 6. The weight of plastics handpieces was 20%-50% of that of metal handpieces. The present results indicate that it is possible to produce a new type of light, silent and aesthetical air turbine handpiece.

ON THE PROBLEM OF CORRECTING TWISTED TURBINE BLADES,

DTIC Science & Technology

TURBINE BLADES , DESIGN), GAS TURBINES , STEAM TURBINES , BLADE AIRFOILS , ASPECT RATIO, FLUID DYNAMICS, SECONDARY FLOW, ANGLE OF ATTACK, INLET GUIDE VANES , CORRECTIONS, PERFORMANCE( ENGINEERING ), OPTIMIZATION, USSR

Optimising use of the mini C-arm in foot and ankle surgery.

PubMed

Gangopadhyay, Soham; Scammell, Brigitte E

2009-01-01

The mini C-arm reduces exposure to ionising radiation compared to the conventional C-arm. Optimising radiation exposure is not only desirable, but also a legal requirement and protocols should be in place to achieve this. Since 2004, all elective foot surgery requiring intraoperative imaging was performed using the mini C-arm. Screening times and radiation doses were recorded for each procedure. Following a learning curve, the screening times stabilised around the median value for the individual procedures. For subtalar or triple arthrodesis this was less than 60 s, for ankle arthrodesis, less than 90 s, for hindfoot arthrodesis using a nail, less than 100 s and for joint injections less than 12 s. Screening time can be used as an audit tool to measure optimum use of the mini C-arm. A protocol is presented including an audit form for every operation where the mini C-arm is used. Radiation protection issues are addressed.

Mini-implants: alternative for oral rehabilitation of a child with ectodermal dysplasia.

PubMed

Mello, Bianca Zeponi Fernandes; Silva, Thiago Cruvinel; Rios, Daniela; Machado, Maria Aparecida Andrade Moreira; Valarelli, Fabrício Pinelli; Oliveira, Thais Marchini

2015-01-01

Ectodermal dysplasia is a rare congenital disease that affects several structures of ectodermal origin. The most commonly related oral characteristics are hypodontia, malformed teeth and underdeveloped alveolar ridges. New alternative treatments are needed due to the failure of the conventional prosthesis retention. This case report outlines the oral rehabilitation treatment of a 9-year-old girl with ectodermal dysplasia. The treatment was performed with conventional prosthesis upon mini-implants. The mini-implants provided prosthetic retention. The patient reported a good adaptation of the dental prosthesis and satisfaction with the treatment. The increased self-esteem improved the socialization skills of the girl. In this case report, use of prosthesis with mini-implants was satisfactory for prosthetic retention. However, clinical studies with long-term follow-up are needed to test the mini-implants as an alternative for oral rehabilitation of children with ectodermal dysplasia.

Turbocharger apparatus

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

Leavesley, M.G.

1993-08-03

Variable turbocharger apparatus is described comprising a compressor housing, a compressor mounted for rotation in the compressor housing, a turbine housing, a turbine mounted for rotation in the turbine housing, a first inlet for enabling air to be conducted to the compressor, an outlet for air from the compressor, a second inlet for enabling exhaust gases from an engine to be conducted to the turbine, a chamber which surrounds the turbine and which receives the exhaust gases from the second inlet before the exhaust gases are conducted to the turbine, a piston which is positioned between the turbine and themore » turbine housing and which is slidable backwards and forwards to form a movable wall separating the turbine from the chamber which surrounds the turbine, a bearing assembly for allowing the rotation of the compressor and the turbine, and a heat shield for shielding the bearing assembly from the exhaust gases, the piston having a plurality of vanes, the piston being such that in its closed position it terminates short of an adjacent part of the turbine housing so that there is always a gap between the end of the piston and the adjacent part of the turbine housing whereby exhaust gases from the chamber can always pass through the gap to act on the turbine, the piston being such that in its open position the gap is increased, and the piston being biased to its closed position against pressure from exhaust gases in the chamber during use of the variable turbocharger apparatus whereby the piston slides backwards and forwards to vary the gap in dependence upon engine operating conditions, and the variable turbocharger apparatus being such that the vanes on the piston enter into slots in the heat shield.« less

Preliminary design of an alternate high-temperature turbine. A topical report for Phase II of the High-Temperature-Turbine Technology Program

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

Strough, R.I.

The feasibility of designing a convectively air-cooled turbine to operate in the environment of a 3000/sup 0/F combustor exit temperature with maximum turbine airfoil metal temperatures held to 1500/sup 0/F was established. The United Technologies-Kraftwerk Union V84.3 gas turbine design was used as the basic configuration for the design of the 3000/sup 0/F turbine. Turbine cooling requirements were determined based on the use of the modified V84.3 type silo combustor with a pattern factor of 0.1. The convective air-cooling technology levels in terms of cooling effectiveness required to satisfy the airfoil cooling requirements were identified. Cooling schemes and fabrication technologiesmore » required are discussed. Turbine airfoil cooling technology levels required for the 3000/sup 0/F engine were selected. The performance of the 3000/sup 0/F convectively air-cooled gas turbine in simple and combined cycle was calculated. The 3000/sup 0/F gas turbine combined-cycle system provides an increase in power of 61% and a decrease in heat rate of 10% compared to a similar system with a combustor exit temperature of 2210/sup 0/F and the same airflow. The development of a successful 3000/sup 0/F convectively air-cooled turbine can be accomplished with a reasonable design and fabrication development effort on the cooled turbine airfoils. Use of the convectively air-cooled turbine provides the transfer of technology from extensive aircraft engines developed programs and operating experience to industrial gas turbines. It eliminates the requirement for large investments in alternate cooling techniques tailored specifically for industrial engines which offer no additional benefits.« less

Turbulent Coolant Dispersion in the Wake of a Turbine Vane Trailing Edge

DTIC Science & Technology

2015-01-01

turbine vane from a gas turbine engine. The understanding and prediction of the highly three-dimensional flow and heat transfer in a modern gas turbine ...engine is a problem that has not been solved over many years of turbomachinery research. Turbine blades and vanes are both internally and...Approved for public release; distribution is unlimited. Turbulent Coolant Dispersion in the Wake of a Turbine Vane Trailing Edge The views, opinions and/or

Progress in net shape fabrication of alpha SiC turbine components

NASA Technical Reports Server (NTRS)

Storm, R. S.; Naum, R. G.

1983-01-01

The development status of component technology in an automotive gas turbine Ceramic Applications in Turbine Engines program is discussed, with attention to such materials and processes having a low cost, net shape fabrication potential as sintered alpha-SiC that has been fashioned by means of injection molding, slip casting, and isostatic pressing. The gas turbine elements produced include a gasifier turbine rotor, a turbine wheel, a connecting duct, a combustor baffle, and a transition duct.

Effects of Pulsing on Film Cooling of Gas Turbine Airfoils

DTIC Science & Technology

2005-05-09

turbine engine . 15. NUMBER OF PAGES 70 14. SUBJECT TERMS: Turbine blade ; Film cooling ; Pulsed jet 16. PRICE CODE 17...with additional research, ultimately allowing for an increased efficiency in a gas turbine engine . 2 Keywords Turbine blade Film cooling Pulsed jet ... engine for aircraft propulsion…………………. 11 Figure 2: Thermodynamic cycle of a general turbine engine . ………………………..…… 11

Modified Adaptive Control for Region 3 Operation in the Presence of Wind Turbine Structural Modes

NASA Technical Reports Server (NTRS)

Frost, Susan Alane; Balas, Mark J.; Wright, Alan D.

2010-01-01

Many challenges exist for the operation of wind turbines in an efficient manner that is reliable and avoids component fatigue and failure. Turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, possibly causing component fatigue and failure. Wind turbine manufacturers are highly motivated to reduce component fatigue and failure that can lead to loss of revenue due to turbine down time and maintenance costs. The trend in wind turbine design is toward larger, more flexible turbines that are ideally suited to adaptive control methods due to the complexity and expense required to create accurate models of their dynamic characteristics. In this paper, we design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed horizontal axis wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the excitation of structural modes in the wind turbine. The control objective is accomplished by collectively pitching the turbine blades. The adaptive collective pitch controller for Region 3 was compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller. The adaptive controller will demonstrate the ability to regulate generator speed in Region 3, while accommodating gusts, and reducing the excitation of certain structural modes in the wind turbine.

Stationary Engineers Apprenticeship. Related Training Modules. 15.1-15.5 Turbines.

ERIC Educational Resources Information Center

Lane Community Coll., Eugene, OR.

This learning module, one in a series of 20 related training modules for apprentice stationary engineers, deals with turbines. addressed in the individual instructional packages included in the module are the following topics: types and components of steam turbines, steam turbine auxiliaries, operation and maintenance of steam turbines, and gas…

Automotive gas turbine fuel control

NASA Technical Reports Server (NTRS)

Gold, H. (Inventor)

1978-01-01

A fuel control system is reported for automotive-type gas turbines and particulary advanced gas turbines utilizing variable geometry components to improve mileage and reduce pollution emission. The fuel control system compensates for fuel density variations, inlet temperature variations, turbine vane actuation, acceleration, and turbine braking. These parameters are utilized to control various orifices, spool valves and pistons.

Advanced Thermoplastic Resins for Manufacturing Wind Turbine Blades |

Science.gov Websites

Turbine Blades Advanced Thermoplastic Resins for Manufacturing Wind Turbine Blades At its Composites Arkema's Elium liquid thermoplastic resin. Photo of men working on turbine blades in a dome-shaped building composite structures of wind turbine blades. Capabilities Learn more about NREL's IACMI projects and its

3D Blade Vibration Measurements on an 80 m Diameter Wind Turbine by Using Non-contact Remote Measurement Systems

NASA Astrophysics Data System (ADS)

Ozbek, Muammer; Rixen, Daniel J.

Non-contact optical measurement systems photogrammetry and laser interferometry are introduced as cost efficient alternatives to the conventional wind turbine/farm monitoring systems that are currently in use. The proposed techniques are proven to provide an accurate measurement of the dynamic behavior of a 2.5 MW—80 m diameter—wind turbine. Several measurements are taken on the test turbine by using 4 CCD cameras and 1 laser vibrometer and the response of the turbine is monitored from a distance of 220 m. The results of the infield tests and the corresponding analyses show that photogrammetry (also can be called as videogrammetry or computer vision technique) enable the 3D deformations of the rotor to be measured at 33 different points simultaneously with an average accuracy of ±25 mm, while the turbine is rotating. Several important turbine modes can also be extracted from the recorded data. Similarly, laser interferometry (used for the parked turbine only) provides very valuable information on the dynamic properties of the turbine structure. Twelve different turbine modes can be identified from the obtained response data.

Visualization and analysis of vortex-turbine intersections in wind farms.

PubMed

Shafii, Sohail; Obermaier, Herald; Linn, Rodman; Koo, Eunmo; Hlawitschka, Mario; Garth, Christoph; Hamann, Bernd; Joy, Kenneth I

2013-09-01

Characterizing the interplay between the vortices and forces acting on a wind turbine's blades in a qualitative and quantitative way holds the potential for significantly improving large wind turbine design. This paper introduces an integrated pipeline for highly effective wind and force field analysis and visualization. We extract vortices induced by a turbine's rotation in a wind field, and characterize vortices in conjunction with numerically simulated forces on the blade surfaces as these vortices strike another turbine's blades downstream. The scientifically relevant issue to be studied is the relationship between the extracted, approximate locations on the blades where vortices strike the blades and the forces that exist in those locations. This integrated approach is used to detect and analyze turbulent flow that causes local impact on the wind turbine blade structure. The results that we present are based on analyzing the wind and force field data sets generated by numerical simulations, and allow domain scientists to relate vortex-blade interactions with power output loss in turbines and turbine life expectancy. Our methods have the potential to improve turbine design to save costs related to turbine operation and maintenance.

Experimental study to the influences of rotational speed and blade shape on water vortex turbine performance

NASA Astrophysics Data System (ADS)

Kueh, T. C.; Beh, S. L.; Ooi, Y. S.; Rilling, D. G.

2017-04-01

Water vortex turbine utilizes the natural behaviour of water to form free surface vortex for energy extraction. This allows simple construction and ease of management on the whole water vortex power plant system. To our findings, the literature study specifically on water vortex turbine is inadequate and low efficiency was reported. Influences of operating speed and blade shape on turbine performance are the two parameters investigated in this study. Euler Turbomachinery Equation and velocity triangle are used in the improvement analysis. Two turbines with flat blades and curved blades are tested and compared. Both turbines show similar rotational speed at no load condition. This suggested that the circulation force of the water vortex has more dominant effect on the turbine rotational speed, compared to the turbine’s geometry. Flat-blades turbine showed maximum efficiency of 21.63% at 3.27 rad/s whereas curved-blades turbine showed 22.24% at 3.56 rad/s. When operating load is applied, the backward-leaning curve helps the turbine blades to reduce the disturbance on the water vortex, and hence provide a better performance.

The prediction of the hydrodynamic performance of tidal current turbines

NASA Astrophysics Data System (ADS)

Y Xiao, B.; Zhou, L. J.; Xiao, Y. X.; Wang, Z. W.

2013-12-01

Nowadays tidal current energy is considered to be one of the most promising alternative green energy resources and tidal current turbines are used for power generation. Prediction of the open water performance around tidal turbines is important for the reason that it can give some advice on installation and array of tidal current turbines. This paper presents numerical computations of tidal current turbines by using a numerical model which is constructed to simulate an isolated turbine. This paper aims at studying the installation of marine current turbine of which the hydro-environmental impacts influence by means of numerical simulation. Such impacts include free-stream velocity magnitude, seabed and inflow direction of velocity. The results of the open water performance prediction show that the power output and efficiency of marine current turbine varies from different marine environments. The velocity distribution should be clearly and the suitable unit installation depth and direction be clearly chosen, which can ensure the most effective strategy for energy capture before installing the marine current turbine. The findings of this paper are expected to be beneficial in developing tidal current turbines and array in the future.

Effect of blades number to performance of Savonius water turbine in water pipe

NASA Astrophysics Data System (ADS)

Hamzah, Imron; Prasetyo, Ari; Tjahjana, D. D. D. Prija; Hadi, Syamsul

2018-02-01

Savonius is usually known as a wind turbine that works efficiently at low wind speed. In this research, the Savonius turbine is proposed for a pico hydro power plant that is installed straightly on the 3-inch vertical pipeline of rainwater and household waste. The Savonius water turbine was designed with blade curvature angle of 70°, the aspect ratio of 1, turbine diameter of 82 mm, and endplate ratio of 1,1. The experimental study investigated the effect of blades number to the performance of Savonius turbine on various volume flow rate of water. Savonius turbine with three blades number generated the highest coefficient of performance of 0.23 on tip speed ratio of 1.7 compared to turbines with the number of other blades.

Locations and attributes of wind turbines in Colorado, 2011

USGS Publications Warehouse

Carr, Natasha B.; Diffendorfer, James E.; Fancher, Tammy; Hawkins, Sarah J.; Latysh, Natalie; Leib, Kenneth J.; Matherne, Anne Marie

2013-01-01

This dataset represents an update to U.S. Geological Survey Data Series 597. Locations and attributes of wind turbines in Colorado, 2009 (available at http://pubs.usgs.gov/ds/597/). This updated Colorado wind turbine Data Series provides geospatial data for all 1,204 wind turbines established within the State of Colorado as of September 2011, an increase of 297 wind turbines from 2009. Attributes specific to each turbine include: turbine location, manufacturer and model, rotor diameter, hub height, rotor height, potential megawatt output, land ownership, county, and development status of the wind turbine. Wind energy facility data for each turbine include: facility name, facility power capacity, number of turbines associated with each facility to date, facility developer, facility ownership, and year the facility went online. The locations of turbines are derived from 1-meter true-color aerial photographs produced by the National Agriculture Imagery Program (NAIP); the photographs have a positional accuracy of about ±5 meters. Locations of turbines constructed during or prior to August 2009 are based on August 2009 NAIP imagery and turbine locations constructed after August 2009 were based on September 2011 NAIP imagery. The location of turbines under construction during September 2011 likely will be less accurate than the location of existing turbines. This data series contributes to an Online Interactive Energy Atlas developed by the U.S. Geological Survey (http://my.usgs.gov/eerma/). The Energy Atlas synthesizes data on existing and potential energy development in Colorado and New Mexico and includes additional natural resource data layers. This information may be used by decisionmakers to evaluate and compare the potential benefits and tradeoffs associated with different energy development strategies or scenarios. Interactive maps, downloadable data layers, comprehensive metadata, and decision-support tools also are included in the Energy Atlas. The format of the Energy Atlas is designed to facilitate the integration of information about energy with key terrestrial and aquatic resources for evaluating resource values and minimizing risks from energy development.

Locations and attributes of wind turbines in New Mexico, 2011

USGS Publications Warehouse

Carr, Natasha B.; Diffendorfer, James B.; Fancher, Tammy; Hawkins, Sarah J.; Latysh, Natalie; Leib, Kenneth J.; Matherne, Anne Marie

2013-01-01

This dataset represents an update to U.S. Geological Survey Data Series 596. Locations and attributes of wind turbines in New Mexico, 2009 (available at http://pubs.usgs.gov/ds/596/).This updated New Mexico wind turbine Data Series provides geospatial data for all 562 wind turbines established within the State of New Mexico as of June 2011, an increase of 155 wind turbines from 2009. Attributes specific to each turbine include: turbine location, manufacturer and model, rotor diameter, hub height, rotor height, potential megawatt output, land ownership, county, and development status of wind turbine. Wind energy facility data for each turbine include: facility name, facility power capacity, number of turbines associated with each facility to date, facility developer, facility ownership, and year the facility went online. The locations of turbines are derived from 1-meter true-color aerial photographs produced by the National Agriculture Imagery Program (NAIP); the photographs have a positional accuracy of about ±5 meters. The locations of turbines constructed during or prior to August 2009 are based on August 2009 NAIP imagery and turbine locations constructed after August 2009 were based June 2011 NAIP imagery. The location of turbines under construction during June 2011 likely will be less accurate than the location of existing turbines. This data series contributes to an Online Interactive Energy Atlas developed by the U.S. Geological Survey (http://my.usgs.gov/eerma/). The Energy Atlas synthesizes data on existing and potential energy development in Colorado and New Mexico and includes additional natural resource data layers. This information may be used by decisionmakers to evaluate and compare the potential benefits and tradeoffs associated with different energy development strategies or scenarios. Interactive maps, downloadable data layers, comprehensive metadata, and decision-support tools also are included in the Energy Atlas. The format of the Energy Atlas is designed to facilitate the integration of information about energy with key terrestrial and aquatic resources for evaluating resource values and minimizing risks from energy development.

Component Performance Investigation of J71 Type II Turbines: III - Overall Performance of J71 Type IIA Turbine

NASA Technical Reports Server (NTRS)

Schum, Harold J.; Davison, Elmer H.; Petrash, Donald A.

1955-01-01

The over-all component performance characteristics of the J71 Type IIA three-stage turbine were experimentally determined over a range of speed and over-all turbine total-pressure ratio at inlet-air conditions af 35 inches of mercury absolute and 700 deg. R. The results are compared with those obtained for the J71 Type IIF turbine, which was previously investigated, the two turbines being designed for the same engine application. Geometrically the two turbines were much alike, having the same variation of annular flow area and the same number of blades for corresponding stator and rotor rows. However, the blade throat areas downstream of the first stator of the IIA turbine were smaller than those of the IIF; and the IIA blade profiles were curve-backed, whereas those of the IIF were straight-backed. The IIA turbine passed the equivalent design weight flow and had a brake internal efficiency of 0.880 at design equivalent speed and work output. A maximum efficiency of 0.896 occurred at 130 percent of design equivalent speed and a pressure ratio of 4.0. The turbine had a wide range of efficient operation. The IIA turbine had slightly higher efficiencies than the IIF turbine at comparable operating conditions. The fact that the IIA turbine obtained the design equivalent weight flow at the design equivalent operating point was probably a result of the decrease in the blading throat areas downstream of the first stator from those of the IIF turbine, which passed 105 percent of design weight flow at the corresponding operating point. The third stator row of blades of the IIA turbine choked at the design equivalent speed and at an over-all pressure ratio of 4.2; the third rotor choked at a pressure ratio of approximately 4.9

MOD-2 wind turbine farm stability study

NASA Technical Reports Server (NTRS)

Hinrichsen, E. N.

1980-01-01

The dynamics of single and multiple 2.5 ME, Boeing MOD-2 wind turbine generators (WTGs) connected to utility power systems were investigated. The analysis was based on digital simulation. Both time response and frequency response methods were used. The dynamics of this type of WTG are characterized by two torsional modes, a low frequency 'shaft' mode below 1 Hz and an 'electrical' mode at 3-5 Hz. High turbine inertia and low torsional stiffness between turbine and generator are inherent features. Turbine control is based on electrical power, not turbine speed as in conventional utility turbine generators. Multi-machine dynamics differ very little from single machine dynamics.

The swirl turbine

NASA Astrophysics Data System (ADS)

Haluza, M.; Pochylý, F.; Rudolf, P.

2012-11-01

In the article is introduced the new type of the turbine - swirl turbine. This turbine is based on opposite principle than Kaplan turbine. Euler equation is satisfied in the form gHηh = -u2vu2. From this equation is seen, that inflow of liquid into the runner is without rotation and on the outflow is a rotation of liquid opposite of rotation of runner. This turbine is suitable for small head and large discharge. Some constructional variants of this turbine are introduced in the article and theoretical aspects regarding losses in the draft tube. The theory is followed by computational simulations in Fluent and experiments using laser Doppler anemometry.

Method for Making Measurements of the Post-Combustion Residence Time in a Gas Turbine Engine

NASA Technical Reports Server (NTRS)

Miles, Jeffrey H. (Inventor)

2017-01-01

A method of measuring a residence time in a gas-turbine engine is disclosed that includes measuring a combustor pressure signal at a combustor entrance and a turbine exit pressure signal at a turbine exit. The method further includes computing a cross-spectrum function between the combustor pressure signal and the turbine exit pressure signal, calculating a slope of the cross-spectrum function, shifting the turbine exit pressure signal an amount corresponding to a time delay between the measurement of the combustor pressure signal and the turbine exit pressure signal, and recalculating the slope of the cross-spectrum function until the slope reaches zero.

Nucleated casting for the production of large superalloy ingots

NASA Astrophysics Data System (ADS)

Carter, William T.; Jones, Robin M. Forbes

2005-04-01

The gas turbine industry is continuously driven to achieve higher thermodynamic efficiency, higher electrical output, and higher reliability through turbine design improvements. The specific component of interest in this article is the turbine wheel, which is the rotating hub on which turbine blades are mounted. The wheel is mechanically loaded by both axial and centrifugal forces and thermally loaded by heat that is conducted from the turbine blades. Currently, the turbine wheel is forged from an ingot that is triple-melted, but nucleated casting is under development as a long-term option. This article describes the investigation into nucleated casting technology for future turbine wheel production.

Closed loop air cooling system for combustion turbines

DOEpatents

Huber, David John; Briesch, Michael Scot

1998-01-01

Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor and delivered to passages internal to one or more of a combustor and turbine hot parts. The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts.

Closed loop air cooling system for combustion turbines

DOEpatents

Huber, D.J.; Briesch, M.S.

1998-07-21

Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor and delivered to passages internal to one or more of a combustor and turbine hot parts. The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts. 1 fig.

A wind turbine hybrid simulation framework considering aeroelastic effects

NASA Astrophysics Data System (ADS)

Song, Wei; Su, Weihua

2015-04-01

In performing an effective structural analysis for wind turbine, the simulation of turbine aerodynamic loads is of great importance. The interaction between the wake flow and the blades may impact turbine blades loading condition, energy yield and operational behavior. Direct experimental measurement of wind flow field and wind profiles around wind turbines is very helpful to support the wind turbine design. However, with the growth of the size of wind turbines for higher energy output, it is not convenient to obtain all the desired data in wind-tunnel and field tests. In this paper, firstly the modeling of dynamic responses of large-span wind turbine blades will consider nonlinear aeroelastic effects. A strain-based geometrically nonlinear beam formulation will be used for the basic structural dynamic modeling, which will be coupled with unsteady aerodynamic equations and rigid-body rotations of the rotor. Full wind turbines can be modeled by using the multi-connected beams. Then, a hybrid simulation experimental framework is proposed to potentially address this issue. The aerodynamic-dominant components, such as the turbine blades and rotor, are simulated as numerical components using the nonlinear aeroelastic model; while the turbine tower, where the collapse of failure may occur under high level of wind load, is simulated separately as the physical component. With the proposed framework, dynamic behavior of NREL's 5MW wind turbine blades will be studied and correlated with available numerical data. The current work will be the basis of the authors' further studies on flow control and hazard mitigation on wind turbine blades and towers.

Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatography – tandem mass spectrometry

USDA-ARS?s Scientific Manuscript database

This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

The Mini-Economy: Integrating Economics into the Elementary Curriculum.

ERIC Educational Resources Information Center

Indiana State Dept. of Education, Indianapolis.

The focus of this guide is to simulate real world economic activity in the classroom by using a form of economics instruction called a " mini-economy." In a mini-economy, students earn play money in a variety of ways and spend it at a class store or class auction. Students apply for classroom jobs, run businesses, pay taxes, buy rental properties,…

Effects and Implications of Mini-Lectures on Learning in First-Semester General Chemistry

ERIC Educational Resources Information Center

Toto, Joe; Booth, Kathy

2008-01-01

This study describes the efficacy of a novel tool, mini-lecture movies, in teaching Web based general chemistry. The analysis shows a marked improvement in student learning, as evidenced by a corresponding increase in homework and final exam scores. Students with access to mini-lecture movies scored 11.2% (p = 0.016) higher than students who did…

Sesame and You, Two--A Teacher's Helper: A Revised Guide to Accompany a Videotape Package of Twenty Sesame Street Mini Shows.

ERIC Educational Resources Information Center

Sylves, David, Ed.; Sardina, Kathleen, Ed.

The teaching guide is intended to accompany a videotape package of 20 Sesame Street Mini Shows selected for their relevance to the education of young hearing impaired children. Individually described are segments of each Mini Show in terms of a description, captions, general objective, specific objectives, necessary preteaching, and related…

Case Study: Mini-Case Studies: Small Infusions of Active Learning for Large-Lecture Courses

ERIC Educational Resources Information Center

Carloye, Lisa

2017-01-01

In this article, the author introduces the usage of case studies to be an excellent method for engaging students through stories. The author notes she developed a series of mini-case studies that can be implemented, with a little advance preparation, within a 10- to 15-minute window during lecture. What makes them "mini" case studies?…

Status of the core and the mini core collections for the U.S. gemrplasm collection of peanut

USDA-ARS?s Scientific Manuscript database

To maximize their usefulness, core and mini core collections should be dynamic. The peanut core collection was developed in the early 1990's, and the mini core was developed in the late 1990's. Research has shown that these collections can be used to improve the efficiency and effectiveness of ide...

New York State Occupational Education Mini-Grant Program. 1972 Final Report.

ERIC Educational Resources Information Center

Alwell, William

The mini-grant concept has emerged in recent years as a specific catalyst for the promotion of educational change. A mini-grant is a small grant awarded to an individual (usually a teacher or supervisor) in order that he might investigate or further develop an idea within the classroom or school setting. Developed in the State of New York, this…

Designing a Microhydraulically driven Mini robotic Squid

DTIC Science & Technology

2016-05-20

applications for microrobots include remote monitoring, surveillance, search and rescue, nanoassembly, medicine, and in-vivo surgery . Robotics platforms...Secretary of Defense for Research and Engineering. Designing a Microhydraulically-driven Mini- robotic Squid by Kevin Dehan Meng B.S., U.S. Air...Committee on Graduate Students 2 Designing a Microhydraulically-driven Mini- robotic Squid by Kevin Dehan Meng Submitted to the Department

Embedding Hands-On Mini Laboratory Experiences in a Core Undergraduate Fluid Mechanics Course: A Pilot Study

ERIC Educational Resources Information Center

Han, Duanduan; Ugaz, Victor

2017-01-01

Three self-contained mini-labs were integrated into a core undergraduate fluid mechanics course, with the goal of delivering hands-on content in a manner scalable to large class sizes. These mini-labs supported learning objectives involving friction loss in pipes, flow measurement, and centrifugal pump analysis. The hands-on experiments were…

The Effects of Teaching a Science Topic in the Regents Living Environment Course in a Mini-Lesson Instructional Environment

ERIC Educational Resources Information Center

Barrows, Calder James

2010-01-01

This study investigated the effects on high school students' understanding of studying a science topic in the Regents Living Environment course using a Mini-Lesson educational protocol. Mini-Lesson instruction is one of guided instruction, which consists primarily of three sections. First, a brief, focused section in which the teachers explicitly…

Cost analysis of a mini-facet heliostat

NASA Astrophysics Data System (ADS)

Hall, Colin; Pratt, Rodney; Farrant, David; Corsi, Clotilde; Pye, John; Coventry, Joe

2017-06-01

A significant problem with conventional heliostats is off-axis astigmatism, which increases the spot size at the central receiver, limiting the temperature and efficiency of solar thermal systems. Inspired by low-cost mini-actuators used for car wing mirrors, we examine the economic feasibility of a heliostat with individually adjustable mini-facets to correct astigmatic effects, and we compare three alternative tracking configurations.

Fast-Flowering Mini-Maize: Seed to Seed in 60 Days

PubMed Central

McCaw, Morgan E.; Wallace, Jason G.; Albert, Patrice S.; Buckler, Edward S.; Birchler, James A.

2016-01-01

Two lines of Zea mays were developed as a short-generation model for maize. The Fast-Flowering Mini-Maize (FFMM) lines A and B are robust inbred lines with a significantly shorter generation time, much smaller stature, and better greenhouse adaptation than traditional maize varieties. Five generations a year are typical. FFMM is the result of a modified double-cross hybrid between four fast-flowering lines: Neuffer’s Early ACR (full color), Alexander’s Early Early Synthetic, Tom Thumb Popcorn, and Gaspe Flint, followed by selection for early flowering and desirable morphology throughout an 11-generation selfing regime. Lines A and B were derived from different progeny of the initial hybrid, and crosses between Mini-Maize A and B exhibit heterosis. The ancestry of each genomic region of Mini-Maize A and B was inferred from the four founder populations using genotyping by sequencing. Other genetic and genomic tools for these lines include karyotypes for both lines A and B, kernel genetic markers y1 (white endosperm) and R1-scm2 (purple endosperm and embryo) introgressed into Mini-Maize A, and ∼24× whole-genome resequencing data for Mini-Maize A. PMID:27440866

Pitfall Traps and Mini-Winkler Extractor as Complementary Methods to Sample Soil Coleoptera.

PubMed

Carneiro, A C; Batistella, D A; Battirola, L D; Marques, M I

2016-02-01

We compared abundance, species richness, and capture efficiency with pitfall traps and mini-Winkler extractors to examine their use as complementary methods for sampling soil Coleoptera during dry (2010) and high water seasons (2011) in three areas, including inundated and non-inundated regions, in the Pantanal of Poconé, Mato Grosso, Brazil. We paired treatments with two 10 × 10 m plots in inundated and non-inundated locations that were repeated three times in each location for a total of 18 plots. In each plot, we used nine pitfall traps and collected 2 m(2) of leaf litter and surface soil samples with mini-Winkler extractors. We collected a total of 4260 adult beetles comprising 36 families, 113 genera, and 505 species. Most were caught in pitfalls (69%) and the remainder in the mini-Winkler extractors (31%). Each method provided distinct information about the beetle community: 252 species were captured only in pitfall traps, 147 using only the mini-Winkler extractors, and these methods shared another 106 species. Pitfall and mini-Winkler contribute in different ways for the sampling of the soil beetle community, and so they should be considered complementary for a more thorough assessment of community diversity.

Minimally invasive knee arthroplasty: An overview

PubMed Central

Tria, Alfred J; Scuderi, Giles R

2015-01-01

Minimally invasive surgery (MIS) for arthroplasty of the knee began with surgery for unicondylar knee arthroplasty (UKA). Partial knee replacements were designed in the 1970s and were amenable to a more limited exposure. In the 1990s Repicci popularized the MIS for UKA. Surgeons began to apply his concepts to total knee arthroplasty. Four MIS surgical techniques were developed: quadriceps sparing, mini-mid vastus, mini-subvastus, and mini-medial parapatellar. The quadriceps sparing technique is the most limited one and is also the most difficult. However, it is the least invasive and allows rapid recovery. The mini-midvastus is the most common technique because it affords slightly better exposure and can be extended. The mini-subvastus technique entirely avoids incising the quadriceps extensor mechanism but is time consuming and difficult in the obese and in the muscular male patient. The mini-parapatellar technique is most familiar to surgeons and represents a good starting point for surgeons who are learning the techniques. The surgeries are easier with smaller instruments but can be performed with standard ones. The techniques are accurate and do lead to a more rapid recovery, with less pain, less blood loss, and greater motion if they are appropriately performed. PMID:26601062

Miniature Robotic Spacecraft for Inspecting Other Spacecraft

NASA Technical Reports Server (NTRS)

Fredrickson, Steven; Abbott, Larry; Duran, Steve; Goode, Robert; Howard, Nathan; Jochim, David; Rickman, Steve; Straube, Tim; Studak, Bill; Wagenknecht, Jennifer;

An educational video game for nutrition of young people: Theory and design

PubMed Central

Ledoux, Tracey; Griffith, Melissa; Thompson, Debbe; Nguyen, Nga; Watson, Kathy; Baranowski, Janice; Buday, Richard; Abdelsamad, Dina; Baranowski, Tom

2016-01-01

Background Playing Escape from DIAB (DIAB) and Nanoswarm (NANO), epic video game adventures, increased fruit and vegetable consumption among a multi-ethnic sample of 10–12 year old children during pilot testing. Key elements of both games were educational mini-games embedded in the overall game that promoted knowledge acquisition regarding diet, physical activity and energy balance. 95–100% of participants demonstrated mastery of these mini-games suggesting knowledge acquisition. Aim This article describes the process of designing and developing the educational mini-games. A secondary purpose was to explore the experience of children while playing the games. Method The educational games were based on Social Cognitive and Mastery Learning Theories. A multidisciplinary team of behavioral nutrition, PA, and video game experts designed, developed, and tested the mini-games. Results Alpha testing revealed children generally liked the mini-games and found them to be reasonably challenging. Process evaluation data from pilot testing revealed almost all participants completed nearly all educational mini-games in a reasonable amount of time suggesting feasibility of this approach. Conclusions Future research should continue to explore the use of video games in educating children to achieve healthy behavior changes. PMID:27547019

Quantitative assessment of orthodontic mini-implant displacement: the effect of initial force application.

PubMed

Holst, Alexandra Ioana; Karl, Matthias; Karolczak, Marek; Goellner, Matthias; Holst, Stefan

2010-01-01

Primary stability and micromovement of orthodontic mini-implants depends on a number of factors and influences clinical success or failure. The purpose of this study was to assess the behavior of orthodontic mini-implants upon initial load application. Orthodontic mini-implants (n = 39) were inserted in the alveolar process of maxillary human cadaver specimens (n = 10). Increasing horizontal forces (up to 2.5 N) were applied, and triggered images were taken in 0.5-N load intervals. Additionally, peri-implant parameters based on micro-CT volume data were recorded. Data were subjected to a two-sided nonparametric Wilcoxon signed rank test, and between-group comparisons were assessed with a Mann-Whitney test (alpha = .05). Initial load application led to displacement beyond elastic recovery of the surrounding bone after force release (P < .001). Cortical thickness and insertion depth, despite numeric differences, did not reveal any statistical differences, while displacement of mini-implants was significantly affected by contact to neighboring teeth (P < .001). Insertion technique and initial load application on orthodontic mini-implants may be regarded as two crucial factors for success, while repeated application of orthodontic force does not seem to increase screw mobility.

An educational video game for nutrition of young people: Theory and design.

PubMed

Ledoux, Tracey; Griffith, Melissa; Thompson, Debbe; Nguyen, Nga; Watson, Kathy; Baranowski, Janice; Buday, Richard; Abdelsamad, Dina; Baranowski, Tom

2016-08-01

Playing Escape from DIAB (DIAB) and Nanoswarm (NANO) , epic video game adventures, increased fruit and vegetable consumption among a multi-ethnic sample of 10-12 year old children during pilot testing. Key elements of both games were educational mini-games embedded in the overall game that promoted knowledge acquisition regarding diet, physical activity and energy balance. 95-100% of participants demonstrated mastery of these mini-games suggesting knowledge acquisition. This article describes the process of designing and developing the educational mini-games. A secondary purpose was to explore the experience of children while playing the games. The educational games were based on Social Cognitive and Mastery Learning Theories. A multidisciplinary team of behavioral nutrition, PA, and video game experts designed, developed, and tested the mini-games. Alpha testing revealed children generally liked the mini-games and found them to be reasonably challenging. Process evaluation data from pilot testing revealed almost all participants completed nearly all educational mini-games in a reasonable amount of time suggesting feasibility of this approach. Future research should continue to explore the use of video games in educating children to achieve healthy behavior changes.

Silicon micro-fabricated miniature polymer electrolyte fuel cells

NASA Astrophysics Data System (ADS)

Kelley, Shawn Christopher

2000-10-01

The present thesis relates the design, fabrication, and testing of a unique type of silicon-based, miniature fuel cell. The fuel cell electrodes were constructed using standard silicon micro-fabrication techniques, and were used to construct miniature polymer electrolyte fuel cells (PEFCs) using NafionRTM. During testing, methanol and oxygen were the common reactants, but hydrogen and oxygen could be used as well. A novel form of an electrodeposited Pt:Ru alloy was developed for use as a methanol electrooxidation catalyst in the mini-PEFCs. An optimized mini-PEFC design was developed, tested, and compared with large PEFCs on the basis of performance. Mini-PEFC performance was equivalent to that of large PEFCs when scaled for active-area, but was limited by the function of the oxygen electrode. The rate of methanol crossover in a methanol/oxygen mini-PEFC was predicted using Fick's first law and the electrode chip feed-hole area. It was shown that the present mini-PEFC design could function as a fuel cell material test structure. Additionally, the mini-PEFCs were tested as two-cell stacks and as methanol sensors. The miniature, silicon-based PEFCs developed here successfully incorporate the essential aspects of a large PEFC in a smaller, simpler design.

Nicotine Lozenges in the Relief of Behaviorally Provoked Craving.

PubMed

Nides, Mitchell; Shanga, Gilbert Marava; Bishop, Amanda; Becker, William D

2018-05-01

Environmental cues may precipitate nicotine cravings in smokers. We present 2 studies exploring the efficacy of nicotine mini lozenges to reduce nicotine craving in smokers following behavioral provocation. Healthy smokers aged ≥18 years enrolled. In Study 1, participants were stratified by number of cigarettes smoked daily; Study 2 enrolled only heavy smokers. After an abstinence period, participants engaged in behavioral provocation to induce nicotine craving before receiving a nicotine mini lozenge (Study 1: 1.5 mg or 4 mg; Study 2: 4 mg) or matching placebo. Craving was assessed using a 100-mm visual analogue scale, and safety was monitored. In Study 1, neither nicotine mini lozenge dose significantly reduced craving in smokers versus placebo. In Study 2, 4-mg nicotine mini lozenges significantly reduced craving scores 5 minutes post-treatment (least-square mean [LSM] change from baseline: -41.8; 95% confidence interval [CI]: -45.8, -37.7) versus placebo (-25.9; 95% CI: -30.0, -21.8; p < .001). Adverse events were infrequent, mild in intensity, and more common with the 4-mg nicotine mini lozenges. Behaviorally provoked nicotine craving can be significantly and safely reduced in heavy/high-dependency smokers with 4-mg nicotine mini lozenges.

Mini AERCam Inspection Robot for Human Space Missions

NASA Technical Reports Server (NTRS)

Fredrickson, Steven E.; Duran, Steve; Mitchell, Jennifer D.

2004-01-01

The Engineering Directorate of NASA Johnson Space Center has developed a nanosatellite-class free-flyer intended for future external inspection and remote viewing of human spacecraft. The Miniature Autonomous Extravehicular Robotic Camera (Mini AERCam) technology demonstration unit has been integrated into the approximate form and function of a flight system. The spherical Mini AERCam free flyer is 7.5 inches in diameter and weighs approximately 10 pounds, yet it incorporates significant additional capabilities compared to the 35 pound, 14 inch AERCam Sprint that flew as a Shuttle flight experiment in 1997. Mini AERCam hosts a full suite of miniaturized avionics, instrumentation, communications, navigation, imaging, power, and propulsion subsystems, including digital video cameras and a high resolution still image camera. The vehicle is designed for either remotely piloted operations or supervised autonomous operations including automatic stationkeeping and point-to-point maneuvering. Mini AERCam is designed to fulfill the unique requirements and constraints associated with using a free flyer to perform external inspections and remote viewing of human spacecraft operations. This paper describes the application of Mini AERCam for stand-alone spacecraft inspection, as well as for roles on teams of humans and robots conducting future space exploration missions.

Quality Assurance Framework for Mini-Grids

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

Baring-Gould, Ian; Burman, Kari; Singh, Mohit

Providing clean and affordable energy services to the more than 1 billion people globally who lack access to electricity is a critical driver for poverty reduction, economic development, improved health, and social outcomes. More than 84% of populations without electricity are located in rural areas where traditional grid extension may not be cost-effective; therefore, distributed energy solutions such as mini-grids are critical. To address some of the root challenges of providing safe, quality, and financially viable mini-grid power systems to remote customers, the U.S. Department of Energy (DOE) teamed with the National Renewable Energy Laboratory (NREL) to develop a Qualitymore » Assurance Framework (QAF) for isolated mini-grids. The QAF for mini-grids aims to address some root challenges of providing safe, quality, and affordable power to remote customers via financially viable mini-grids through two key components: (1) Levels of service: Defines a standard set of tiers of end-user service and links them to technical parameters of power quality, power availability, and power reliability. These levels of service span the entire energy ladder, from basic energy service to high-quality, high-reliability, and high-availability service (often considered 'grid parity'); (2) Accountability and performance reporting framework: Provides a clear process of validating power delivery by providing trusted information to customers, funders, and/or regulators. The performance reporting protocol can also serve as a robust monitoring and evaluation tool for mini-grid operators and funding organizations. The QAF will provide a flexible alternative to rigid top-down standards for mini-grids in energy access contexts, outlining tiers of end-user service and linking them to relevant technical parameters. In addition, data generated through implementation of the QAF will provide the foundation for comparisons across projects, assessment of impacts, and greater confidence that will drive investment and scale-up in this sector. The QAF implementation process also defines a set of implementation guidelines that help the deployment of mini-grids on a regional or national scale, helping to insure successful rapid deployment of these relatively new remote energy options. Note that the QAF is technology agnostic, addressing both alternating current (AC) and direct current (DC) mini-grids, and is also applicable to renewable, fossil-fuel, and hybrid systems.« less

Turbine inner shroud and turbine assembly containing such inner shroud

DOEpatents

Bagepalli, Bharat Sampathkumaran; Corman, Gregory Scot; Dean, Anthony John; DiMascio, Paul Stephen; Mirdamadi, Massoud

2001-01-01

A turbine inner shroud and a turbine assembly. The turbine assembly includes a turbine stator having a longitudinal axis and having an outer shroud block with opposing and longitudinally outward facing first and second sides having open slots. A ceramic inner shroud has longitudinally inward facing hook portions which can longitudinally and radially surround a portion of the sides of the outer shroud block. In one attachment, the hook portions are engageable with, and are positioned within, the open slots.

Aerodynamic design and analysis of a highly loaded turbine exhaust

NASA Technical Reports Server (NTRS)

Huber, F. W.; Montesdeoca, X. A.; Rowey, R. J.

1993-01-01

The aerodynamic design and analysis of a turbine exhaust volute manifold is described. This turbine exhaust system will be used with an advanced gas generator oxidizer turbine designed for very high specific work. The elevated turbine stage loading results in increased discharge Mach number and swirl velocity which, along with the need for minimal circumferential variation of fluid properties at the turbine exit, represent challenging volute design requirements. The design approach, candidate geometries analyzed, and steady state/unsteady CFD analysis results are presented.

Cold-air performance of the compressor-drive turbine of the Department of Energy baseline automobile gas-turbine engine

NASA Technical Reports Server (NTRS)

Roelke, R. J.; Mclallin, K. L.

1978-01-01

The aerodynamic performance of the compressor-drive turbine of the DOE baseline gas-turbine engine was determined over a range of pressure ratios and speeds. In addition, static pressures were measured in the diffusing transition duct located immediately downstream of the turbine. Results are presented in terms of mass flow, torque, specific work, and efficiency for the turbine and in terms of pressure recovery and effectiveness for the transition duct.

Small Horizontal Axis Wind Turbine under High Speed Operation: Study of Power Evaluation

NASA Astrophysics Data System (ADS)

Moh. M. Saad, Magedi; Mohd, Sofian Bin; Zulkafli, Mohd Fadhli Bin; Abdullah, Aslam Bin; Rahim, Mohammad Zulafif Bin; Subari, Zulkhairi Bin; Rosly, Nurhayati Binti

2017-10-01

Mechanical energy is produced through the rotation of wind turbine blades by air that convert the mechanical energy into electrical energy. Wind turbines are usually designed to be use for particular applications and design characteristics may vary depending on the area of use. The variety of applications is reflected on the size of turbines and their infrastructures, however, performance enhancement of wind turbine may start by analyzing the small horizontal axis wind turbine (SHAWT) under high wind speed operation. This paper analyzes the implementations of SHAWT turbines and investigates their performance in both simulation and real life. Depending on the real structure of the rotor geometry and aerodynamic test, the power performance of the SHAWT was simulated using ANSYS-FLUENT software at different wind speed up to 33.33 m/s (120km/h) in order to numerically investigate the actual turbine operation. Dynamic mesh and user define function (UDF) was used for revolving the rotor turbine via wind. Simulation results were further validated by experimental data and hence good matching was yielded. And for reducing the energy producing cost, car alternator was formed to be used as a small horizontal wind turbine. As a result, alternator-based turbine system was found to be a low-cost solution for exploitation of wind energy.

Augmented Adaptive Control of a Wind Turbine in the Presence of Structural Modes

NASA Technical Reports Server (NTRS)

Frost, Susan A.; Balas, Mark J.; Wright, Alan D.

2010-01-01

Wind turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, potentially causing component fatigue and failure. Two key technology drivers for turbine manufacturers are increasing turbine up time and reducing maintenance costs. Since the trend in wind turbine design is towards larger, more flexible turbines with lower frequency structural modes, manufacturers will want to develop methods to operate in the presence of these modes. Accurate models of the dynamic characteristics of new wind turbines are often not available due to the complexity and expense of the modeling task, making wind turbines ideally suited to adaptive control. In this paper, we develop theory for adaptive control with rejection of disturbances in the presence of modes that inhibit the controller. We use this method to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the interference of certain structural modes in feedback. The control objective is accomplished by collectively pitching the turbine blades. The adaptive pitch controller for Region 3 is compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller.

Cross-flow turbines: progress report on physical and numerical model studies at large laboratory scale

NASA Astrophysics Data System (ADS)

Wosnik, Martin; Bachant, Peter

2016-11-01

Cross-flow turbines show potential in marine hydrokinetic (MHK) applications. A research focus is on accurately predicting device performance and wake evolution to improve turbine array layouts for maximizing overall power output, i.e., minimizing wake interference, or taking advantage of constructive wake interaction. Experiments were carried with large laboratory-scale cross-flow turbines D O (1 m) using a turbine test bed in a large cross-section tow tank, designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. Several turbines of varying solidity were employed, including the UNH Reference Vertical Axis Turbine (RVAT) and a 1:6 scale model of the DOE-Sandia Reference Model 2 (RM2) turbine. To improve parameterization in array simulations, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier-Stokes models. Results are presented for the simulation of performance and wake dynamics of cross-flow turbines and compared with experiments and body-fitted mesh, blade-resolving CFD. Supported by NSF-CBET Grant 1150797, Sandia National Laboratories.

A Numerical Investigation of Turbine Noise Source Hierarchy and Its Acoustic Transmission Characteristics

NASA Technical Reports Server (NTRS)

VanZante, Dale; Envia, Edmane

2008-01-01

Understanding the relative importance of the various turbine noise generation mechanisms and the characteristics of the turbine acoustic transmission loss are essential ingredients in developing robust reduced-order models for predicting the turbine noise signature. A computationally based investigation has been undertaken to help guide the development of a turbine noise prediction capability that does not rely on empiricism. The investigation relies on highly detailed numerical simulations of the unsteady flowfield inside a modern high-pressure turbine (HPT). The simulations are developed using TURBO, which is an unsteady Reynolds-averaged Navier-Stokes (URANS) code capable of multi-stage simulations. The purpose of this study is twofold. First, to determine an estimate of the relative importance of the contributions to the coherent part of the acoustic signature of a turbine from the three potential sources of turbine noise generation, namely, blade-row viscous interaction, potential field interaction, and entropic source associated with the interaction of the blade rows with the temperature nonuniformities caused by the incomplete mixing of the hot fluid and the cooling flow. Second, to develop an understanding of the turbine acoustic transmission characteristics and to assess the applicability of existing empirical and analytical transmission loss models to realistic geometries and flow conditions for modern turbine designs. The investigation so far has concentrated on two simulations: (1) a single-stage HPT and (2) a two-stage HPT and the associated inter-turbine duct/strut segment. The simulations are designed to resolve up to the second harmonic of the blade passing frequency tone in accordance with accepted rules for second order solvers like TURBO. The calculations include blade and vane cooling flows and a radial profile of pressure and temperature at the turbine inlet. The calculation can be modified later to include the combustor pattern factor at the turbine inlet to include that contribution to turbine noise. We shall present preliminary analysis of the results obtained so far in order to assess the validity of such an approach and to seek feedback on improving the approach. This work addresses both Area 1 (Turbine Tone Noise) and Area 5 (Influence of the Turbine on Combustor Noise) topics.

40 CFR 60.4390 - What are my reporting requirements if I operate an emergency combustion turbine or a research and...

Code of Federal Regulations, 2011 CFR

2011-07-01

... operate an emergency combustion turbine or a research and development turbine? 60.4390 Section 60.4390... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Stationary Combustion Turbines Reporting § 60.4390 What are my reporting requirements if I operate an emergency combustion turbine or a research...

40 CFR 60.4390 - What are my reporting requirements if I operate an emergency combustion turbine or a research and...

Code of Federal Regulations, 2010 CFR

2010-07-01

... operate an emergency combustion turbine or a research and development turbine? 60.4390 Section 60.4390... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Stationary Combustion Turbines Reporting § 60.4390 What are my reporting requirements if I operate an emergency combustion turbine or a research...

Cost Effective Repair Techniques for Turbine Airfoils. Volume I

DTIC Science & Technology

1978-11-01

Turbine blades and vanes in current engines are subjected to the most hostile environment...payoff potential in turbine vanes / blades . The criteria used included: • Incidence of damage - Scrapped or damaged turbine airfoils at the ALC centers...Corporate Author: GENERAL ELECTRIC CO CINCINNATI OHIO AIRCRAFT ENGINE GROUP Unclassified Title: (U) Cost Effective Repair Techniques for Turbine

Computational and Experimental Evaluation of a Complex Inlet Swirl Pattern Generation System (POSTPRINT)

DTIC Science & Technology

2016-08-01

Sanders, Chase A. Nessler, William W. Copenhaver, Michael G. List, and Timothy J. Janczewski Turbomachinery Branch Turbine Engine Division AUGUST...Branch Turbine Engine Division Turbine Engine Division Aerospace Systems Directorate //Signature// ROBERT D. HANCOCK Principal Scientist Turbine ...ORGANIZATION Turbomachinery Branch Turbine Engine Division Air Force Research Laboratory, Aerospace Systems Directorate Wright-Patterson Air Force

40 CFR 60.4390 - What are my reporting requirements if I operate an emergency combustion turbine or a research and...

Code of Federal Regulations, 2012 CFR

2012-07-01

... operate an emergency combustion turbine or a research and development turbine? 60.4390 Section 60.4390... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Stationary Combustion Turbines Reporting § 60.4390 What are my reporting requirements if I operate an emergency combustion turbine or a research...

40 CFR 60.4390 - What are my reporting requirements if I operate an emergency combustion turbine or a research and...

Code of Federal Regulations, 2014 CFR

2014-07-01

... operate an emergency combustion turbine or a research and development turbine? 60.4390 Section 60.4390... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Stationary Combustion Turbines Reporting § 60.4390 What are my reporting requirements if I operate an emergency combustion turbine or a research...

40 CFR 60.4390 - What are my reporting requirements if I operate an emergency combustion turbine or a research and...

Code of Federal Regulations, 2013 CFR

2013-07-01

... operate an emergency combustion turbine or a research and development turbine? 60.4390 Section 60.4390... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Stationary Combustion Turbines Reporting § 60.4390 What are my reporting requirements if I operate an emergency combustion turbine or a research...

Advanced Gas Turbine (AGT) Technology Project

NASA Technical Reports Server (NTRS)

1984-01-01

Technical work on the design and effort leading to the testing of a 74.5 kW (100 hp) automotive gas turbine engine is reviewed. Development of the engine compressor, gasifier turbine, power turbine, combustor, regenerator, and secondary system is discussed. Ceramic materials development and the application of such materials in the gas turbine engine components is described.

Plan Turbines 3 & 4, Side View Turbines ...

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

Plan - Turbines 3 & 4, Side View - Turbines 3 & 4, Section A-A - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

Efficiency limit factor analysis for the Francis-99 hydraulic turbine

NASA Astrophysics Data System (ADS)

Zeng, Y.; Zhang, L. X.; Guo, J. P.; Guo, Y. K.; Pan, Q. L.; Qian, J.

2017-01-01

The energy loss in hydraulic turbine is the most direct factor that affects the efficiency of the hydraulic turbine. Based on the analysis theory of inner energy loss of hydraulic turbine, combining the measurement data of the Francis-99, this paper calculates characteristic parameters of inner energy loss of the hydraulic turbine, and establishes the calculation model of the hydraulic turbine power. Taken the start-up test conditions given by Francis-99 as case, characteristics of the inner energy of the hydraulic turbine in transient and transformation law are researched. Further, analyzing mechanical friction in hydraulic turbine, we think that main ingredients of mechanical friction loss is the rotation friction loss between rotating runner and water body, and defined as the inner mechanical friction loss. The calculation method of the inner mechanical friction loss is given roughly. Our purpose is that explore and research the method and way increasing transformation efficiency of water flow by means of analysis energy losses in hydraulic turbine.

Onshore industrial wind turbine locations for the United States up to March 2014

USGS Publications Warehouse

Diffendorfer, James E.; Kramer, Louisa; Ancona, Zachary H.; Garrity, Christopher P.

2015-01-01

Wind energy is a rapidly growing form of renewable energy in the United States. While summary information on the total amounts of installed capacity are available by state, a free, centralized, national, turbine-level, geospatial dataset useful for scientific research, land and resource management, and other uses did not exist. Available in multiple formats and in a web application, these public domain data provide industrial-scale onshore wind turbine locations in the United States up to March 2014, corresponding facility information, and turbine technical specifications. Wind turbine records have been collected and compiled from various public sources, digitized or position verified from aerial imagery, and quality assured and quality controlled. Technical specifications for turbines were assigned based on the wind turbine make and model as described in public literature. In some cases, turbines were not seen in imagery or turbine information did not exist or was difficult to obtain. Uncertainty associated with these is recorded in a confidence rating.

A numerical study of automotive turbocharger mixed flow turbine inlet geometry for off design performance

NASA Astrophysics Data System (ADS)

Leonard, T.; Spence, S.; Early, J.; Filsinger, D.

2013-12-01

Mixed flow turbines represent a potential solution to the increasing requirement for high pressure, low velocity ratio operation in turbocharger applications. While literature exists for the use of these turbines at such operating conditions, there is a lack of detailed design guidance for defining the basic geometry of the turbine, in particular, the cone angle - the angle at which the inlet of the mixed flow turbine is inclined to the axis. This investigates the effect and interaction of such mixed flow turbine design parameters. Computational Fluids Dynamics was initially used to investigate the performance of a modern radial turbine to create a baseline for subsequent mixed flow designs. Existing experimental data was used to validate this model. Using the CFD model, a number of mixed flow turbine designs were investigated. These included studies varying the cone angle and the associated inlet blade angle. The results of this analysis provide insight into the performance of a mixed flow turbine with respect to cone and inlet blade angle.

Parametric performance analysis of steam-injected gas turbine with a thermionic-energy-converter-lined combustor

NASA Technical Reports Server (NTRS)

Choo, Y. K.; Burns, R. K.

1982-01-01

The performance of steam-injected gas turbines having combustors lined with thermionic energy converters (STIG/TEC systems) was analyzed and compared with that of two baseline systems; a steam-injected gas turbine (without a TEC-lined combustor) and a conventional combined gas turbine/steam turbine cycle. Common gas turbine parameters were assumed for all of the systems. Two configurations of the STIG/TEC system were investigated. In both cases, steam produced in an exhaust-heat-recovery boiler cools the TEC collectors. It is then injected into the gas combustion stream and expanded through the gas turbine. The STIG/TEC system combines the advantage of gas turbine steam injection with the conversion of high-temperature combustion heat by TEC's. The addition of TEC's to the baseline steam-injected gas turbine improves both its efficiency and specific power. Depending on system configuration and design parameters, the STIG/TEC system can also achieve higher efficiency and specific power than the baseline combined cycle.

Analytical investigation of chord size and cooling methods on turbine blade cooling requirements. Book 1: Sections 1 through 8 and appendixes A through I

NASA Technical Reports Server (NTRS)

Faulkner, F. E.

1971-01-01

A study was conducted to determine the effect of chord size on air cooled turbine blades. In the preliminary design phase, eight turbine blade cooling configurations in 0.75-in., 1.0-in., and 1.5-in. chord sizes were analyzed to determine the maximum turbine inlet temperature capabilities. A pin fin convection cooled configuration and a film-impingement cooled configuration were selected for a final design analysis in which the maximum turbine inlet temperature was determined as a function of the cooling air inlet temperature and the turbine inlet total pressure for each of the three chord sizes. The cooling air flow requirements were also determined for a varying cooling air inlet temperature with a constant turbine inlet temperature. It was determined that allowable turbine inlet temperature increases with increasing chord for the convection cooled and transpiration cooled designs, however, the film-convection cooled designs did not have a significant change in turbine inlet temperature with chord.

Onshore industrial wind turbine locations for the United States up to March 2014.

PubMed

Diffendorfer, Jay E; Kramer, Louisa A; Ancona, Zach H; Garrity, Christopher P

2015-11-24

Wind energy is a rapidly growing form of renewable energy in the United States. While summary information on the total amounts of installed capacity are available by state, a free, centralized, national, turbine-level, geospatial dataset useful for scientific research, land and resource management, and other uses did not exist. Available in multiple formats and in a web application, these public domain data provide industrial-scale onshore wind turbine locations in the United States up to March 2014, corresponding facility information, and turbine technical specifications. Wind turbine records have been collected and compiled from various public sources, digitized or position verified from aerial imagery, and quality assured and quality controlled. Technical specifications for turbines were assigned based on the wind turbine make and model as described in public literature. In some cases, turbines were not seen in imagery or turbine information did not exist or was difficult to obtain. Uncertainty associated with these is recorded in a confidence rating.

Study on performance and flow field of an undershot cross-flow water turbine comprising different number of blades

NASA Astrophysics Data System (ADS)

Nishi, Yasuyuki; Hatano, Kentaro; Inagaki, Terumi

2017-10-01

Recently, small hydroelectric generators have gained attention as a further development in water turbine technology for ultra low head drops in open channels. The authors have evaluated the application of cross-flow water turbines in open channels as an undershot type after removing the casings and guide vanes to substantially simplify these water turbines. However, because undershot cross-flow water turbines are designed on the basis of cross-flow water turbine runners used in typical pipelines, it remains unclear whether the number of blades has an effect on the performance or flow fields. Thus, in this research, experiments and numerical analyses are employed to study the performance and flow fields of undershot cross-flow water turbines with varying number of blades. The findings show that the turbine output and torque are lower, the fluctuation is significantly higher, and the turbine efficiency is higher for runners with 8 blades as opposed to those with 24 blades.

Wind turbines, flicker, and photosensitive epilepsy: characterizing the flashing that may precipitate seizures and optimizing guidelines to prevent them.

PubMed

Harding, Graham; Harding, Pamela; Wilkins, Arnold

2008-06-01

Wind turbines are known to produce shadow flicker by interruption of sunlight by the turbine blades. Known parameters of the seizure provoking effect of flicker, i.e., contrast, frequency, mark-space ratio, retinal area stimulated and percentage of visual cortex involved were applied to wind turbine features. The proportion of patients affected by viewing wind turbines expressed as distance in multiples of the hub height of the turbine showed that seizure risk does not decrease significantly until the distance exceeds 100 times the hub height. Since risk does not diminish with viewing distance, flash frequency is therefore the critical factor and should be kept to a maximum of three per second, i.e., sixty revolutions per minute for a three-bladed turbine. On wind farms the shadows cast by one turbine on another should not be viewable by the public if the cumulative flash rate exceeds three per second. Turbine blades should not be reflective.

Onshore industrial wind turbine locations for the United States up to March 2014

PubMed Central

Diffendorfer, Jay E.; Kramer, Louisa A.; Ancona, Zach H.; Garrity, Christopher P.

2015-01-01

Wind energy is a rapidly growing form of renewable energy in the United States. While summary information on the total amounts of installed capacity are available by state, a free, centralized, national, turbine-level, geospatial dataset useful for scientific research, land and resource management, and other uses did not exist. Available in multiple formats and in a web application, these public domain data provide industrial-scale onshore wind turbine locations in the United States up to March 2014, corresponding facility information, and turbine technical specifications. Wind turbine records have been collected and compiled from various public sources, digitized or position verified from aerial imagery, and quality assured and quality controlled. Technical specifications for turbines were assigned based on the wind turbine make and model as described in public literature. In some cases, turbines were not seen in imagery or turbine information did not exist or was difficult to obtain. Uncertainty associated with these is recorded in a confidence rating. PMID:26601687

Centaur boost pump turbine icing investigation

NASA Technical Reports Server (NTRS)

Rollbuhler, R. J.

1976-01-01

An investigation was conducted to determine if ice formation in the Centaur vehicle liquid oxygen boost pump turbine could prevent rotation of the pump and whether or not this phenomenon could have been the failure mechanism for the Titan/Centaur vehicle TC-1. The investigation consisted of a series of tests done in the LeRC Space Power Chamber Facility to evaluate evaporative cooling behavior patterns in a turbine as a function of the quantity of water trapped in the turbine and as a function of the vehicle ascent pressure profile. It was found that evaporative freezing of water in the turbine housing, due to rapid depressurization within the turbine during vehicle ascent, could result in the formation of ice that would block the turbine and prevent rotation of the boost pump. But for such icing conditions to exist it would be necessary to have significant quantities of water in the turbine and/or its components, and the turbine housing temperature would have to be colder than 40 F at vehicle liftoff.

A DISTANT RADIO MINI-HALO IN THE PHOENIX GALAXY CLUSTER

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

Van Weeren, R. J.; Andrade-Santos, F.; Forman, W. R.

We report the discovery of extended radio emission in the Phoenix cluster (SPT-CL J2344-4243, z = 0.596) with the Giant Metrewave Radio Telescope (GMRT) at 610 MHz. The diffuse emission extends over a region of at least 400-500 kpc and surrounds the central radio source of the Brightest Cluster Galaxy, but does not appear to be directly associated with it. We classify the diffuse emission as a radio mini-halo, making it the currently most distant mini-halo known. Radio mini-halos have been explained by synchrotron emitting particles re-accelerated via turbulence, possibly induced by gas sloshing generated from a minor merger event. Chandra observationsmore » show a non-concentric X-ray surface brightness distribution, which is consistent with this sloshing interpretation. The mini-halo has a flux density of 17 ± 5 mJy, resulting in a 1.4 GHz radio power of (10.4 ± 3.5) × 10{sup 24} W Hz{sup –1}. The combined cluster emission, which includes the central compact radio source, is also detected in a shallow GMRT 156 MHz observation and together with the 610 MHz data we compute a spectral index of –0.84 ± 0.12 for the overall cluster radio emission. Given that mini-halos typically have steeper radio spectra than cluster radio galaxies, this spectral index should be taken as an upper limit for the mini-halo.« less

Novel miniature mobile cardiac catheterization laboratory for critical cardiovascular disease following natural disasters: a feasibility study.

PubMed

Han, Ya-ling; Liang, Zhuo; Yao, Tian-ming; Sun, Jing-yang; Liang, Ming; Huo, Yu; Wang, Geng; Wang, Xiao-zeng; Liang, Yan-chun; Meng, Wei-hong

2012-03-01

Natural disasters have been frequent in recent years. Effective treatment of patients with cardiovascular disease following natural disasters is an unsolved problem. We aimed to develop a novel miniature mobile cardiac catheterization laboratory (Mini Mobile Cath Lab) to provide emergency interventional services for patients with critical cardiovascular disease following natural disasters. A feasibility study was performed by testing the Mini Mobile Cath Lab on dogs with ST-elevation myocardial infarction (STEMI) model in a hypothetical natural-disaster-stricken area. The Mini Mobile Cath Lab was transported to the hypothetical natural-disaster-stricken area by truck. Coronary angiography and primary percutaneous coronary intervention (PCI) were performed on six dogs with STEMI model. The transportation and transformation of the Mini Mobile Cath Lab were monitored and its functioning was evaluated through the results of animal experiments. The Mini Mobile Cath Lab could be transported by truck at an average speed of 80 km/h on mountain roads during daytime in the winter, under conditions of light snow (-15°C to -20°C/-68°F to -59°F). The average time required to prepare the Mini Mobile Cath Lab after transportation, in a wetland area, was 30 minutes. Coronary angiography, and primary PCI were performed successfully. This preliminary feasibility study of the use of the Mini Mobile Cath Lab for emergency interventional treatment of dogs with STEMI indicated that it may perform well in the rescue of critical cardiovascular disease following natural disasters.

A mini-microscope for in situ monitoring of cells.

PubMed

Kim, Sang Bok; Koo, Kyo-in; Bae, Hojae; Dokmeci, Mehmet R; Hamilton, Geraldine A; Bahinski, Anthony; Kim, Sun Min; Ingber, Donald E; Khademhosseini, Ali

2012-10-21

A mini-microscope was developed for in situ monitoring of cells by modifying off-the-shelf components of a commercial webcam. The mini-microscope consists of a CMOS imaging module, a small plastic lens and a white LED illumination source. The CMOS imaging module was connected to a laptop computer through a USB port for image acquisition and analysis. Due to its compact size, 8 × 10 × 9 cm, the present microscope is portable and can easily fit inside a conventional incubator, and enables real-time monitoring of cellular behaviour. Moreover, the mini-microscope can be used for imaging cells in conventional cell culture flasks, such as Petri dishes and multi-well plates. To demonstrate the operation of the mini-microscope, we monitored the cellular migration of mouse 3T3 fibroblasts in a scratch assay in medium containing three different concentrations of fetal bovine serum (5, 10, and 20%) and demonstrated differential responses depending on serum levels. In addition, we seeded embryonic stem cells inside poly(ethylene glycol) microwells and monitored the formation of stem cell aggregates in real time using the mini-microscope. Furthermore, we also combined a lab-on-a-chip microfluidic device for microdroplet generation and analysis with the mini-microscope and observed the formation of droplets under different flow conditions. Given its cost effectiveness, robust imaging and portability, the presented platform may be useful for a range of applications for real-time cellular imaging using lab-on-a-chip devices at low cost.

A mini-microscope for in situ monitoring of cells†‡

PubMed Central

Kim, Sang Bok; Koo, Kyo-in; Bae, Hojae; Dokmeci, Mehmet R.; Hamilton, Geraldine A.; Bahinski, Anthony; Kim, Sun Min; Ingber, Donald E.

2013-01-01

A mini-microscope was developed for in situ monitoring of cells by modifying off-the-shelf components of a commercial webcam. The mini-microscope consists of a CMOS imaging module, a small plastic lens and a white LED illumination source. The CMOS imaging module was connected to a laptop computer through a USB port for image acquisition and analysis. Due to its compact size, 8 × 10 × 9 cm, the present microscope is portable and can easily fit inside a conventional incubator, and enables real-time monitoring of cellular behaviour. Moreover, the mini-microscope can be used for imaging cells in conventional cell culture flasks, such as Petri dishes and multi-well plates. To demonstrate the operation of the mini-microscope, we monitored the cellular migration of mouse 3T3 fibroblasts in a scratch assay in medium containing three different concentrations of fetal bovine serum (5, 10, and 20%) and demonstrated differential responses depending on serum levels. In addition, we seeded embryonic stem cells inside poly(ethylene glycol) microwells and monitored the formation of stem cell aggregates in real time using the mini-microscope. Furthermore, we also combined a lab-on-a-chip microfluidic device for microdroplet generation and analysis with the mini-microscope and observed the formation of droplets under different flow conditions. Given its cost effectiveness, robust imaging and portability, the presented platform may be useful for a range of applications for real-time cellular imaging using lab-on-a-chip devices at low cost. PMID:22911426

Does the design of mini slings anchoring systems really matter? A biomechanical comparison between Mini Arc™ and Ophira™.

PubMed

Santos-Souza, R; Rodrigues-Palma, P C; Goulart-Fernandes-Dias, F; Teixeira-Siniscalchi, R; Zanettini-Riccetto, C L

2016-11-01

Currently, a sling implant is the standard treatment for stress urinary incontinence in women. To be effective, they require an adequate anchoring system. The aim of this study is compare biomechanical features of fixation systems of two mini slings models available on the market (Ophira™ and Mini Arc™) through a tensile test. Anchoring devices of each sling were surgically implanted in abdominal wall of 15 rats divided into three groups of five animals which were arranged according to the date of post implant euthanasia on 7, 14 and 30 days. Abdominal walls of rats were extracted on bloc containing the anchoring system and were submitted to a tensile strength test to measure the maximum load and elongation until device avulsion from the tissue. The results were compared using Student test t and a 5% cut off was considered significant. The Ophira™ mini sling fixation system demanded a greater maximum load and developed a longer stretch for avulsion from the implanted site at all moments evaluated (p value less than 0.05). There were significant differences in fixation patterns of the anchoring systems, which were exclusively related to their designs. The Ophira™ mini sling fixation device provided better fixation to the abdominal wall of rats compared to the Mini Arc™ device, even in the late post implant period. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Mini-FLOTAC, an innovative direct diagnostic technique for intestinal parasitic infections: experience from the field.

PubMed

Barda, Beatrice Divina; Rinaldi, Laura; Ianniello, Davide; Zepherine, Henry; Salvo, Fulvio; Sadutshang, Tsetan; Cringoli, Giuseppe; Clementi, Massimo; Albonico, Marco

2013-01-01

Soil-transmitted helminths and intestinal protozoa infection are widespread in developing countries, yet an accurate diagnosis is rarely performed. The aim of this study was to evaluate the recently developed mini-FLOTAC method and to compare with currently more widely used techniques for the diagnosis of intestinal parasitic infections in different settings. The study was carried out in Dharamsala, Himachal Pradesh, India, and in Bukumbi, Tanzania. A total of 180 pupils from two primary schools had their stool analyzed (n = 80 in Dharamsala and n = 100 in Bukumbi) for intestinal parasitic infections with three diagnostic methods: direct fecal smear, formol-ether concentration method (FECM) and mini-FLOTAC. Overall, 72% of the pupils were positive for any intestinal parasitic infection, 24% carried dual infections and 11% three infections or more. The most frequently encountered intestinal parasites were Entamoeba coli, Entamoeba histolytica/dispar, Giardia intestinalis, hookworm, (and Schistosoma mansoni, in Tanzania). Statistically significant differences were found in the detection of parasitic infections among the three methods: mini-FLOTAC was the most sensitive method for helminth infections (90% mini-FLOTAC, 60% FECM, and 30% direct fecal smear), whereas FECM was most sensitive for intestinal protozoa infections (88% FECM, 70% direct fecal smear, and 68% mini-FLOTAC). We present the first experiences with the mini-FLOTAC for the diagnosis of intestinal helminths and protozoa. Our results suggest that it is a valid, sensitive and potentially low-cost alternative technique that could be used in resource-limited settings--particularly for helminth diagnosis.

Environmental Effects of Hydrokinetic Turbines on Fish: Desktop and Laboratory Flume Studies

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

Jacobson, Paul T.; Amaral, Stephen V.; Castro-Santos, Theodore

This collection of three reports describes desktop and laboratory flume studies that provide information to support assessment of the potential for injury and mortality of fish that encounter hydrokinetic turbines of various designs installed in tidal and river environments. Behavioral responses to turbine exposure also are investigated to support assessment of the potential for disruptions to upstream and downstream movements of fish. The studies: (1) conducted an assessment of potential injury mechanisms using available data from studies with conventional hydro turbines; (2) developed theoretical models for predicting blade strike probabilities and mortality rates; and (3) performed flume testing with threemore » turbine designs and several fish species and size groups in two laboratory flumes to estimate survival rates and document fish behavior. The project yielded three reports which this document comprises. The three constituent documents are addressed individually below Fish Passage Through Turbines: Application of Conventional Hydropower Data to Hydrokinetic Technologies Fish passing through the blade sweep of a hydrokinetic turbine experience a much less harsh physical environment than do fish entrained through conventional hydro turbines. The design and operation of conventional turbines results in high flow velocities, abrupt changes in flow direction, relatively high runner rotational and blade speeds, rapid and significant changes in pressure, and the need for various structures throughout the turbine passageway that can be impacted by fish. These conditions generally do not occur or are not significant factors for hydrokinetic turbines. Furthermore, compared to conventional hydro turbines, hydrokinetic turbines typically produce relatively minor changes in shear, turbulence, and pressure levels from ambient conditions in the surrounding environment. Injuries and mortality from mechanical injuries will be less as well, mainly due to low rotational speeds and strike velocities, and an absence of structures that can lead to grinding or abrasion injuries. Additional information is needed to rigorously assess the nature and magnitude of effects on individuals and populations, and to refine criteria for design of more fish-friendly hydrokinetic turbines. Evaluation of Fish Injury and Mortality Associated with Hydrokinetic Turbines Flume studies exposed fish to two hydrokinetic turbine designs to determine injury and survival rates and to assess behavioral responses. Also, a theoretical model developed for predicting strike probability and mortality of fish passing through conventional hydro turbines was adapted for use with hydrokinetic turbines and applied to the two designs evaluated during flume studies. The flume tests were conducted with the Lucid spherical turbine (LST), a Darrieus-type (cross flow) turbine, and the Welka UPG, an axial flow propeller turbine. Survival rates for rainbow trout tested with the LST were greater than 98% for both size groups and approach velocities evaluated. Turbine passage survival rates for rainbow trout and largemouth bass tested with the Welka UPG were greater than 99% for both size groups and velocities evaluated. Injury rates of turbine-exposed fish were low with both turbines and generally comparable to control fish. Video observations of the LST demonstrated active avoidance of turbine passage by a large proportion fish despite being released about 25 cm upstream of the turbine blade sweep. Video observations from behavior trials indicated few if any fish pass through the turbines when released farther upstream. The theoretical predictions for the LST indicated that strike mortality would begin to occur at an ambient current velocity of about 1.7 m/s for fish with lengths greater than the thickness of the leading edge of the blades. As current velocities increase above 1.7 m/s, survival was predicted to decrease for fish passing through the LST, but generally remained high (greater than 90%) for fish less than 200 mm in length. Strike mortality was not predicted to occur during passage through a Welka UPG turbine at ambient current velocities less than about 2.5 m/s. Survival and Behavior of Juvenile Atlantic Salmon and Adult American Shad on Exposure to a Hydrokinetic Turbine This report describes a series of experiments designed to measure the effect of exposure to a full-scale, vertical axis hydrokinetic turbine on downstream migrating juvenile Atlantic salmon and upstream migrating adult American shad. Studies were performed in a large-scale, open-channel flume, and all individuals approached the turbine under volitional control. No injuries were observed, and there was no measurable increase in mortality associated with turbine passage. Exposure to the turbine elicited behavioral responses from both species, however, with salmon passing primarily over the downrunning blades. Shad movement was impeded in the presence of the device, as indicated by fewer attempts of shorter duration and reduced distance of ascent up the flume. More work should be performed in both laboratory and field conditions to determine the extent to which observed effects are likely to influence fish in riverine environments. Analysis is needed to assess the potential for multiple units to lead to greater mortality rates or impacts on fish movements and migrations. Additionally, future research should focus on expanding the existing data by developing better estimates of encounter and avoidance probabilities.« less

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... stationary combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as...

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... stationary combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as...

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... stationary combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as...

Ceramic blade attachment system

DOEpatents

Shaffer, J.E.

1995-07-11

A turbine blade having a preestablished rate of thermal expansion is attached to a turbine disc having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine blade and forms a turbine assembly. The turbine blade has a root portion defining a pair of sides having a pair of grooves therein. The turbine assembly includes a pair of flanges between which the turbine blades are positioned. Each of the pair of flanges has a plurality of grooves defined therein. The grooves within the pair of flanges are aligned with the grooves in the blades and have a space formed therebetween. A plurality of spherical balls are positioned within the space. The plurality of spherical balls has a preestablished rate of thermal expansion being equal to the preestablished rate of thermal expansion of the turbine blade. 4 figs.

Ceramic blade attachment system

DOEpatents

Shaffer, James E.

1995-01-01

A turbine blade having a preestablished rate of thermal expansion is attached to a turbine disc having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine blade and forms a turbine assembly. The turbine blade has a root portion defining a pair of sides having a pair of grooves therein. The turbine assembly includes a pair of flanges between which the turbine blades are positioned. Each of the pair of flanges has a plurality of grooves defined therein. The grooves within the pair of flanges are aligned with the grooves in the blades and have a space formed therebetween. A plurality of spherical balls are positioned within the space. The plurality of spherical balls has a preestablished rate of thermal expansion being equal to the preestablished rate of thermal expansion of the turbine blade.

The design of an air-cooled metallic high temperature radial turbine

NASA Technical Reports Server (NTRS)

Snyder, Philip H.; Roelke, Richard J.

1988-01-01

Recent trends in small advanced gas turbine engines call for higher turbine inlet temperatures. Advances in radial turbine technology have opened the way for a cooled metallic radial turbine capable of withstanding turbine inlet temperatures of 2500 F while meeting the challenge of high efficiency in this small flow size range. In response to this need, a small air-cooled radial turbine has been designed utilizing internal blade coolant passages. The coolant flow passage design is uniquely tailored to simultaneously meet rotor cooling needs and rotor fabrication constraints. The rotor flow-path design seeks to realize improved aerodynamic blade loading characteristics and high efficiency while satisfying rotor life requirements. An up-scaled version of the final engine rotor is currently under fabrication and, after instrumentation, will be tested in the warm turbine test facility at the NASA Lewis Research Center.

Cost/benefit studies of advanced materials technologies for future aircraft turbine engines: Materials for advanced turbine engines

NASA Technical Reports Server (NTRS)

Stearns, M.; Wilbers, L.

1982-01-01

Cost benefit studies were conducted on six advanced materials and processes technologies applicable to commercial engines planned for production in the 1985 to 1990 time frame. These technologies consisted of thermal barrier coatings for combustor and high pressure turbine airfoils, directionally solidified eutectic high pressure turbine blades, (both cast and fabricated), and mixers, tail cones, and piping made of titanium-aluminum alloys. A fabricated titanium fan blisk, an advanced turbine disk alloy with improved low cycle fatigue life, and a long-life high pressure turbine blade abrasive tip and ceramic shroud system were also analyzed. Technologies showing considerable promise as to benefits, low development costs, and high probability of success were thermal barrier coating, directionally solidified eutectic turbine blades, and abrasive-tip blades/ceramic-shroud turbine systems.

Thermoelastic steam turbine rotor control based on neural network

NASA Astrophysics Data System (ADS)

Rzadkowski, Romuald; Dominiczak, Krzysztof; Radulski, Wojciech; Szczepanik, R.

2015-12-01

Considered here are Nonlinear Auto-Regressive neural networks with eXogenous inputs (NARX) as a mathematical model of a steam turbine rotor for controlling steam turbine stress on-line. In order to obtain neural networks that locate critical stress and temperature points in the steam turbine during transient states, an FE rotor model was built. This model was used to train the neural networks on the basis of steam turbine transient operating data. The training included nonlinearity related to steam turbine expansion, heat exchange and rotor material properties during transients. Simultaneous neural networks are algorithms which can be implemented on PLC controllers. This allows for the application neural networks to control steam turbine stress in industrial power plants.

Wind flow characteristics in the wakes of large wind turbines. Volume 1: Analytical model development

NASA Technical Reports Server (NTRS)

Eberle, W. R.

1981-01-01

A computer program to calculate the wake downwind of a wind turbine was developed. Turbine wake characteristics are useful for determining optimum arrays for wind turbine farms. The analytical model is based on the characteristics of a turbulent coflowing jet with modification for the effects of atmospheric turbulence. The program calculates overall wake characteristics, wind profiles, and power recovery for a wind turbine directly in the wake of another turbine, as functions of distance downwind of the turbine. The calculation procedure is described in detail, and sample results are presented to illustrate the general behavior of the wake and the effects of principal input parameters.

Investigation of Single-Stage Modified Turbine of Mark 25 Torpedo Power Plant

NASA Technical Reports Server (NTRS)

Hoyt, Jack W.

1947-01-01

Efficiency investigations have been made on a single-stage modification of the turbine of a Mark 25 aerial torpedo to determine the performance of the unit with five different turbine nozzles. The output of the turbine blades was computed by analyzing the windage and mechanical-friction losses of the unit. The turbine was faund to be most efficient with a cast nozzle having sharp-edged inlets to the nine nozzle ports. An analysis af the effectiveness af the first and second stages of the standard Mark 25 torpedo turbine indicates that the first- stage turbine contributes nearly all the brake power produced at blade-jet speed ratios above 0.26.

Turbine Technology Team - An overview of current and planned activities relevant to the National Launch System (NLS)

NASA Technical Reports Server (NTRS)

Griffin, Lisa W.; Huber, Frank W.

1992-01-01

The current status of the activities and future plans of the Turbine Technology Team of the Consortium for Computational Fluid Dynamics is reviewed. The activities of the Turbine Team focus on developing and enhancing codes and models, obtaining data for code validation and general understanding of flows through turbines, and developing and analyzing the aerodynamic designs of turbines suitable for use in the Space Transportation Main Engine fuel and oxidizer turbopumps. Future work will include the experimental evaluation of the oxidizer turbine configuration, the development, analysis, and experimental verification of concepts to control secondary and tip losses, and the aerodynamic design, analysis, and experimental evaluation of turbine volutes.

Mixer-Ejector Wind Turbine: Breakthrough High Efficiency Shrouded Wind Turbine

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

None

2010-02-22

Broad Funding Opportunity Announcement Project: FloDesign Wind Turbine’s innovative wind turbine, inspired by the design of jet engines, could deliver 300% more power than existing wind turbines of the same rotor diameter by extracting more energy over a larger area. FloDesign Wind Turbine’s unique shrouded design expands the wind capture area, and the mixing vortex downstream allows more energy to flow through the rotor without stalling the turbine. The unique rotor and shrouded design also provide significant opportunity for mass production and simplified assembly, enabling mid-scale turbines (approximately 100 kW) to produce power at a cost that is comparable tomore » larger-scale conventional turbines.« less

Materials for Wind Turbine Blades: An Overview.

PubMed

Mishnaevsky, Leon; Branner, Kim; Petersen, Helga Nørgaard; Beauson, Justine; McGugan, Malcolm; Sørensen, Bent F

2017-11-09

A short overview of composite materials for wind turbine applications is presented here. Requirements toward the wind turbine materials, loads, as well as available materials are reviewed. Apart from the traditional composites for wind turbine blades (glass fibers/epoxy matrix composites), natural composites, hybrid and nanoengineered composites are discussed. Manufacturing technologies for wind turbine composites, as well their testing and modelling approaches are reviewed.

77 FR 74865 - Notice of Availability of the Final Environmental Impact Statement for the Searchlight Wind...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-18

... Record of Decision. The proposed wind turbines located on the SWE project would be up to 262-feet tall... up to 415 feet. In addition to the wind turbines, the proposed project would require the construction... turbine layout, an 87 wind turbine layout, and a no-action alternative. The 87 wind turbine alternative is...

Eutectic Composite Turbine Blade Development

DTIC Science & Technology

1976-11-01

turbine blades for aircraft engines . An MC carbide fiber reinforced eutectic alloy, NiTaC-13...composites in turbine blades for aircraft engines . An MC carbide fiber reinforced eutectic alloy, NiTaC-13 and the low pressure turbine blade of the...identified that appeared to have potential for application to aircraft engine turbine blade hardware. The potential benefits offered by these materials

Tacholess order-tracking approach for wind turbine gearbox fault detection

NASA Astrophysics Data System (ADS)

Wang, Yi; Xie, Yong; Xu, Guanghua; Zhang, Sicong; Hou, Chenggang

2017-09-01

Monitoring of wind turbines under variable-speed operating conditions has become an important issue in recent years. The gearbox of a wind turbine is the most important transmission unit; it generally exhibits complex vibration signatures due to random variations in operating conditions. Spectral analysis is one of the main approaches in vibration signal processing. However, spectral analysis is based on a stationary assumption and thus inapplicable to the fault diagnosis of wind turbines under variable-speed operating conditions. This constraint limits the application of spectral analysis to wind turbine diagnosis in industrial applications. Although order-tracking methods have been proposed for wind turbine fault detection in recent years, current methods are only applicable to cases in which the instantaneous shaft phase is available. For wind turbines with limited structural spaces, collecting phase signals with tachometers or encoders is difficult. In this study, a tacholess order-tracking method for wind turbines is proposed to overcome the limitations of traditional techniques. The proposed method extracts the instantaneous phase from the vibration signal, resamples the signal at equiangular increments, and calculates the order spectrum for wind turbine fault identification. The effectiveness of the proposed method is experimentally validated with the vibration signals of wind turbines.

Fish schooling as a basis for vertical axis wind turbine farm design.

PubMed

Whittlesey, Robert W; Liska, Sebastian; Dabiri, John O

2010-09-01

Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may experience only small decreases (or even increases) in an individual turbine's power coefficient when placed in close proximity to neighbors, thus yielding much higher power outputs for a given area of land. A potential flow model of inter-VAWT interactions is developed to investigate the effect of changes in VAWT spatial arrangement on the array performance coefficient, which compares the expected average power coefficient of turbines in an array to a spatially isolated turbine. A geometric arrangement based on the configuration of shed vortices in the wake of schooling fish is shown to significantly increase the array performance coefficient based upon an array of 16 x 16 wind turbines. The results suggest increases in power output of over one order of magnitude for a given area of land as compared to HAWTs.

Visualization and Analysis of Vortex-Turbine Intersections in Wind Farms.

PubMed

Shafii, Sohail; Obermaier, Harald; Linn, Rodman; Koo, Eunmo; Hlawitschka, Mario; Garth, Christoph; Hamann, Bernd; Joy, Kenneth

2013-02-13

Characterizing the interplay between the vortices and forces acting on a wind turbine's blades in a qualitative and quantitative way holds the potential for significantly improving large wind turbine design. The paper introduces an integrated pipeline for highly effective wind and force field analysis and visualization. We extract vortices induced by a turbine's rotation in a wind field, and characterize vortices in conjunction with numerically simulated forces on the blade surfaces as these vortices strike another turbine's blades downstream. The scientifically relevant issue to be studied is the relationship between the extracted, approximate locations on the blades where vortices strike the blades and the forces that exist in those locations. This integrated approach is used to detect and analyze turbulent flow that causes local impact on the wind turbine blade structure. The results that we present are based on analyzing the wind and force field data sets generated by numerical simulations, and allow domain scientists to relate vortex-blade interactions with power output loss in turbines and turbine life-expectancy. Our methods have the potential to improve turbine design in order to save costs related to turbine operation and maintenance.

K-65-12.8 condensing steam turbine

NASA Astrophysics Data System (ADS)

Valamin, A. E.; Kultyshev, A. Yu.; Gol'dberg, A. A.; Sakhnin, Yu. A.; Bilan, V. N.; Stepanov, M. Yu.; Polyaeva, E. N.; Shekhter, M. V.; Shibaev, T. L.

2016-11-01

A new condensing steam turbine K-65-12.8 is considered, which is the continuation of the development of the steam turbine family of 50-70 MW and the fresh steam pressure of 12.8 MPa, such as twocylinder T-50-12.8 and T-60/65-12.8 turbines. The turbine was developed using the modular design. The design and the main distinctive features of the turbine are described, such as a single two-housing cylinder with the steam flow loop; the extraction from the blading section for the regeneration, the inner needs, and heating; and the unification of some assemblies of serial turbines with shorter time of manufacture. The turbine uses the throttling steam distribution; steam from a boiler is supplied to a turbine through a separate valve block consisting of a central shut-off valve and two side control valves. The blading section of a turbine consists of 23 stages: the left flow contains ten stages installed in the inner housing and the right flow contains 13 stages with diaphragm placed in holders installed in the outer housing. The disks of the first 16 stages are forged together with a rotor, and the disks of the rest stages are mounted. Before the two last stages, the uncontrolled steam extraction is performed for the heating of a plant with the heat output of 38-75 GJ/h. Also, a turbine has five regenerative extraction points for feed water heating and the additional steam extraction to a collector for the inner needs with the consumption of up to 10 t/h. The feasibility parameters of a turbine plant are given. The main solutions for the heat flow diagram and the layout of a turbine plant are presented. The main principles and features of the microprocessor electro hydraulic control and protection system are formulated.

High-Order Numerical Simulations of Wind Turbine Wakes

NASA Astrophysics Data System (ADS)

Kleusberg, E.; Mikkelsen, R. F.; Schlatter, P.; Ivanell, S.; Henningson, D. S.

2017-05-01

Previous attempts to describe the structure of wind turbine wakes and their mutual interaction were mostly limited to large-eddy and Reynolds-averaged Navier-Stokes simulations using finite-volume solvers. We employ the higher-order spectral-element code Nek5000 to study the influence of numerical aspects on the prediction of the wind turbine wake structure and the wake interaction between two turbines. The spectral-element method enables an accurate representation of the vortical structures, with lower numerical dissipation than the more commonly used finite-volume codes. The wind-turbine blades are modeled as body forces using the actuator-line method (ACL) in the incompressible Navier-Stokes equations. Both tower and nacelle are represented with appropriate body forces. An inflow boundary condition is used which emulates homogeneous isotropic turbulence of wind-tunnel flows. We validate the implementation with results from experimental campaigns undertaken at the Norwegian University of Science and Technology (NTNU Blind Tests), investigate parametric influences and compare computational aspects with existing numerical simulations. In general the results show good agreement between the experiments and the numerical simulations both for a single-turbine setup as well as a two-turbine setup where the turbines are offset in the spanwise direction. A shift in the wake center caused by the tower wake is detected similar to experiments. The additional velocity deficit caused by the tower agrees well with the experimental data. The wake is captured well by Nek5000 in comparison with experiments both for the single wind turbine and in the two-turbine setup. The blade loading however shows large discrepancies for the high-turbulence, two-turbine case. While the experiments predicted higher thrust for the downstream turbine than for the upstream turbine, the opposite case was observed in Nek5000.

Features of steam turbine cooling by the example of an SKR-100 turbine for supercritical steam parameters

NASA Astrophysics Data System (ADS)

Arkadyev, B. A.

2015-10-01

Basic principles of cooling of high-temperature steam turbines and constructive solutions used for development of the world's first cooled steam turbine SKR-100 (R-100-300) are described. Principal differences between the thermodynamic properties of cooling medium in the steam and gas turbines and the preference of making flow passes of cooled cylinders of steam turbines as reactive are shown. Some of its operation results and their conclusions are given. This turbine with a power of 100 MW, initial steam parameters approximately 30 MPa and 650°C, and back pressure 3 MPa was made by a Kharkov turbine plant in 1961 and ran successfully at a Kashira GRES (state district power plant) up to 1979, when it was taken out of use in a still fully operating condition. For comparison, some data on construction features and operation results of the super-high pressure cylinder of steam turbines of American Philo 6 (made by General Electric Co.) and Eddystone 1 (made by Westinghouse Co.) power generating units, which are close to the SKR-100 turbine by design initial steam parameters and the implementation time, are given. The high operational reliability and effectiveness of the cooling system that was used in the super-high pressure cylinder of the SKR-100 turbine of the power-generating unit, which were demonstrated in operation, confirms rightfulness and expediency of principles and constructive solutions laid at its development. As process steam temperatures are increased, the realization of the proposed approach to cooling of multistage turbines makes it possible to limit for large turbine parts the application of new, more expensive high-temperature materials, which are required for making steam boilers, and, in some cases, to do completely away with their utilization.

Single Rotor Turbine

DOEpatents

Platts, David A.

2004-10-26

A rotor for use in turbine applications has a centrifugal compressor having axially disposed spaced apart fins forming passages and an axial turbine having hollow turbine blades interleaved with the fins and through which fluid from the centrifugal compressor flows.

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

... combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as defined by...

40 CFR 63.6100 - What emission and operating limitations must I meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... combustion turbine, a lean premix oil-fired stationary combustion turbine, a diffusion flame gas-fired stationary combustion turbine, or a diffusion flame oil-fired stationary combustion turbine as defined by...

6. ROOF OF TURBINE BUILDING AND OF L.P. BOILER ROOM ...

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

6. ROOF OF TURBINE BUILDING AND OF L.P. BOILER ROOM FROM NORTH END OF TURBINE BUILDING ROOF - Portland General Electric Company, Turbine Building, 1841 Southeast Water Street, Portland, Multnomah County, OR

Surgical management of fractured orthodontic mini- implant- a case report.

PubMed

Desai, Manthan; Jain, Anoop; Sumra, Nida

2015-01-01

The idea of absolute anchorage has always been an elusive goal for clinicians. Orthodontic mini-implants or temporary anchorage devices allow tooth movements previously thought to be impossible or difficult. Although extensive literature exists on use of temporary anchorage devices, their failures have been hardly focused upon, especially implant fracture. The following case report describes successful management of fractured orthodontic mini-implant.

[Mini-percutaneous nephrolithotomy in the treatment of un-hydronephrotic cata-staghorn renal calculi].

PubMed

Gao, Ning; Chen, He-Qun; Qi, Lin; Yang, Zhong-Qing; Qi, Fan; Zhang, Xiang-Yang

2007-08-01

To evaluate the surgical techniques and clinical effects of mini-percutaneous nephrolithotomy (mini-PCNL) in the treatment of un-hydronephrotic cata-staghorn renal calculi. The clinical data of 46 cases (31 males and 15 females) treated by mini-PCNL were retrospectively analyzed. There were mono-renal calculi in 38 patients (3 patients were the isolated renal calculi) while the other 8 combined opposite side upper urinary tract calculi. The diameter of calculi ranged from 4.2 to 6.4 (mean=5.2) cm. Puncturation was guided by B-type ultrasound. Lithotripsy by air pressure path lithotripter and/or holmium laser was done when the pervium was established. The pervium in the 46 patients was successfully established by one-session puncturation with B-type ultrasonography guidance. The operative time ranged from 140 to 280 (mean=190) min. The amount of blood ranged from 50 to 200 (mean=100) mL and no one needed blood transfusion. Calculus was completely removed in 18 patients (39.1%). Calculi in 10 patients (21.7%) were completely removed among the 20 patients who underwent second-look mini-PCNL. Calculi in 1 of the 3 cases were completely removed by third-look mini-PCNL. Left-over calculi in 17 patients (8 patients after the first time mini-PCNL, 7 patients after second-look, and 2 patients after third-look) were treated by extracorporeal shock-wave lithotripsy (ESWL) and 8 were removed completely. All the 46 patients were followed up for 4 to 48 months. None of them had nephro-hydrops or stenosis. Renal function re-investigation showed that 8 patients recovered and 2 improved in the 10 patients who had azotemia before. Two (5.4%, 2/37) had calculus recurrence in 37 cases which calculi were completely removed before. The size and amount of left-over calculi in 3 patients (33.3%, 3/9) were increasing. Mini-PCNL is effective and causes less trauma for un-hydronephrotic cata-staghorn renal calculi. Mini-PCNL combined ESWL may substitute the open operation and is the preferred method for un-hydronephrotic renal cata-staghorn calculi.

Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study

PubMed Central

AUNMEUNGTONG, W.; KHONGKHUNTHIAN, P.; RUNGSIYAKULL, P.

2016-01-01

SUMMARY Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Materials and methods Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. Results There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Conclusions Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Clinical implications Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant should exhibit the same behavior to chewing force. PMID:28042449

Mini vs standard percutaneous nephrolithotomy for renal stones: a comparative study.

PubMed

ElSheemy, Mohammed S; Elmarakbi, Akram A; Hytham, Mohammed; Ibrahim, Hamdy; Khadgi, Sanjay; Al-Kandari, Ahmed M

2018-03-16

To compare the outcome of mini-percutaneous nephrolithotomy (Mini-PNL) versus standard-PNL for renal stones. Retrospective study was performed between March 2010 and May 2013 for patients treated by Mini-PNL or standard-PNL through 18 and 30 Fr tracts, respectively, using pneumatic lithotripsy. Semirigid ureteroscope (8.5/11.5 Fr) was used for Mini-PNL and 24 Fr nephroscope for standard-PNL. Both groups were compared in stone free rate(SFR), complications and operative time using Student-t, Mann-Whitney, Chi square or Fisher's exact tests as appropriate in addition to logistic regression analysis. P < 0.05 was considered statistically significant. Mini-PNL (378) and standard-PNL (151) were nearly comparable in patients and stones criteria including stone burden (3.77 ± 2.21 vs 3.77 ± 2.43 cm 2 ; respectively). There was no significant difference in number of tracts or supracostal puncture. Mini-PNL had longer operative time (68.6 ± 29.09 vs 60.49 ± 11.38 min; p = 0.434), significantly shorter hospital stay (2.43 ± 1.46 vs 4.29 ± 1.28 days) and significantly higher rate of tubeless PNL (75.1 vs 4.6%). Complications were significantly higher in standard-PNL (7.9 vs 20.5%; p < 0.001). SFR was significantly lower in Mini-PNL (89.9 vs 96%; p = 0.022). This significant difference was found with multiple stones and large stone burden (> 2 cm 2 ), but the SFR was comparable between both groups with single stone or stone burden ≤ 2 cm. Logistic regression analysis confirmed significantly higher complications and SFR with standard-PNL but with significantly shorter operative time. Mini-PNL has significantly lower SFR when compared to standard-PNL (but clinically comparable) with markedly reduced complications and hospital stay. Most of cases can be performed tubeless. The significant difference in SFR was found with multiple stones or large stone burden (> 2 cm 2 ), but not with single stones or stone burden ≤ 2 cm 2 .

Rasch analysis of the Mini-Mental Adjustment to Cancer Scale (mini-MAC) among a heterogeneous sample of long-term cancer survivors: A cross-sectional study

PubMed Central

2012-01-01

Background The mini-Mental Adjustment to Cancer Scale (mini-MAC) is a well-recognised, popular measure of coping in psycho-oncology and assesses five cancer-specific coping strategies. It has been suggested that these five subscales could be grouped to form the over-arching adaptive and maladptive coping subscales to facilitate the interpretation and clinical application of the scale. Despite the popularity of the mini-MAC, few studies have examined its psychometric properties among long-term cancer survivors, and further validation of the mini-MAC is needed to substantiate its use with the growing population of survivors. Therefore, this study examined the psychometric properties and dimensionality of the mini-MAC in a sample of long-term cancer survivors using Rasch analysis. Methods RUMM 2030 was used to analyse the mini-MAC data (n=851). Separate Rasch analyses were conducted for each of the original mini-MAC subscales as well as the over-arching adaptive and maladaptive coping subscales to examine summary and individual model fit statistics, person separation index (PSI), response format, local dependency, targeting, item bias (or differential item functioning -DIF), and dimensionality. Results For the fighting spirit, fatalism, and helplessness-hopelessness subscales, a revised three-point response format seemed more optimal than the original four-point response. To achieve model fit, items were deleted from four of the five subscales – Anxious Preoccupation items 7, 25, and 29; Cognitive Avoidance items 11 and 17; Fighting Spirit item 18; and Helplessness-Hopelessness items 16 and 20. For those subscales with sufficient items, analyses supported unidimensionality. Combining items to form the adaptive and maladaptive subscales was partially supported. Conclusions The original five subscales required item deletion and/or rescaling to improve goodness of fit to the Rasch model. While evidence was found for overarching subscales of adaptive and maladaptive coping, extensive modifications were necessary to achieve this result. Further exploration and validation of over-arching subscales assessing adaptive and maladaptive coping is necessary with cancer survivors. PMID:22607052

Comparative Clinical Study of Conventional Dental Implants and Mini Dental Implants for Mandibular Overdentures: A Randomized Clinical Trial.

PubMed

Aunmeungtong, Weerapan; Kumchai, Thongnard; Strietzel, Frank P; Reichart, Peter A; Khongkhunthian, Pathawee

2017-04-01

Dental implant-retained overdentures have been chosen as the treatment of choice for complete mandibular removable dentures. Dental implants, such as mini dental implants, and components for retaining overdentures, are commercially available. However, comparative clinical studies comparing mini dental implants and conventional dental implants using different attachment for implant-retained overdentures have not been well documented. To compare the clinical outcomes of using two mini dental implants with Equator ® attachments, four mini dental implants with Equator attachments, or two conventional dental implants with ball attachments, by means of a randomized clinical trial. Sixty patients received implant-retained mandibular overdentures in the interforaminal region. The patients were divided into three groups. In Groups 1 and 2, two and four mini dental implants, respectively, were placed and immediately loaded by overdentures, using Equator ® attachments. In Group 3, conventional implants were placed. After osseointegration, the implants were loaded by overdentures, using ball attachments. The study distribution was randomized and double-blinded. Outcome measures included changes in radiological peri-implant bone level from surgery to 12 months postinsertion, prosthodontic complications and patient satisfaction. The cumulative survival rate in the three clinical groups after one year was 100%. There was no significant difference (p < 0.05) in clinical results regarding the number (two or four) of mini dental implants with Equator attachments. However, there was a significant difference in marginal bone loss and patient satisfaction between those receiving mini dental implants with Equator attachments and conventional dental implants with ball attachments. The marginal bone resorption in Group 3 was significantly higher than in Groups 1 and 2 (p < 0.05); there were no significant differences between Groups 1 and 2. There was no significant difference in patient satisfaction between Groups 1 and 2 but it was significantly higher than that in Group3 (p < 0.05). Two and four mini dental implants can be immediately used successfully for retaining lower complete dentures, as shown after a 1-year follow up. © 2016 Wiley Periodicals, Inc.

A Comparison of Four Gravimetric Fine Particle Sampling Methods.

PubMed

Yanosky, Jeff D; Maclntosh, David L

2001-06-01

A study was conducted to compare four gravimetric methods of measuring fine particle (PM 2.5 ) concentrations in air: the BGI, Inc. PQ200 Federal Reference Method PM 2.5 (FRM) sampler; the Harvard-Marple Impactor (HI); the BGI, Inc. GK2.05 KTL Respirable/Thoracic Cyclone (KTL); and the AirMetrics MiniVol (MiniVol). Pairs of FRM, HI, and KTL samplers and one MiniVol sampler were collocated and 24-hr integrated PM 2.5 samples were collected on 21 days from January 6 through April 9, 2000. The mean and standard deviation of PM 2.5 levels from the FRM samplers were 13.6 and 6.8 μg/m 3 , respectively. Significant systematic bias was found between mean concentrations from the FRM and the MiniVol (1.14 μg/m 3 , p = 0.0007), the HI and the MiniVol (0.85 μg/m 3 , p = 0.0048), and the KTL and the MiniVol (1.23 μg/m 3 , p = 0.0078) according to paired t test analyses. Linear regression on all pairwise combinations of the sampler types was used to evaluate measurements made by the samplers. None of the regression intercepts was significantly different from 0, and only two of the regression slopes were significantly different from 1, that for the FRM and the MiniVol [β 1 = 0.91, 95% CI (0.83-0.99)] and that for the KTL and the MiniVol [ = 0.88, 95% CI (0.78-0.98)]. Regression R 2 terms were 0.96 or greater between all pairs of samplers, and regression root mean square error terms (RMSE) were 1.65 μg/m 3 or less. These results suggest that the MiniVol will underestimate measurements made by the FRM, the HI, and the KTL by an amount proportional to PM 2.5 concentration. Nonetheless, these results indicate that all of the sampler types are comparable if ~10% variation on the mean levels and on individual measurement levels is considered acceptable and the actual concentration is within the range of this study (5-35 μg/m 3 ).

A comparison of four gravimetric fine particle sampling methods.

PubMed

Yanosky, J D; MacIntosh, D L

2001-06-01

A study was conducted to compare four gravimetric methods of measuring fine particle (PM2.5) concentrations in air: the BGI, Inc. PQ200 Federal Reference Method PM2.5 (FRM) sampler; the Harvard-Marple Impactor (HI); the BGI, Inc. GK2.05 KTL Respirable/Thoracic Cyclone (KTL); and the AirMetrics MiniVol (MiniVol). Pairs of FRM, HI, and KTL samplers and one MiniVol sampler were collocated and 24-hr integrated PM2.5 samples were collected on 21 days from January 6 through April 9, 2000. The mean and standard deviation of PM2.5 levels from the FRM samplers were 13.6 and 6.8 microg/m3, respectively. Significant systematic bias was found between mean concentrations from the FRM and the MiniVol (1.14 microg/m3, p = 0.0007), the HI and the MiniVol (0.85 microg/m3, p = 0.0048), and the KTL and the MiniVol (1.23 microg/m3, p = 0.0078) according to paired t test analyses. Linear regression on all pairwise combinations of the sampler types was used to evaluate measurements made by the samplers. None of the regression intercepts was significantly different from 0, and only two of the regression slopes were significantly different from 1, that for the FRM and the MiniVol [beta1 = 0.91, 95% CI (0.83-0.99)] and that for the KTL and the MiniVol [beta1 = 0.88, 95% CI (0.78-0.98)]. Regression R2 terms were 0.96 or greater between all pairs of samplers, and regression root mean square error terms (RMSE) were 1.65 microg/m3 or less. These results suggest that the MiniVol will underestimate measurements made by the FRM, the HI, and the KTL by an amount proportional to PM2.5 concentration. Nonetheless, these results indicate that all of the sampler types are comparable if approximately 10% variation on the mean levels and on individual measurement levels is considered acceptable and the actual concentration is within the range of this study (5-35 microg/m3).

Outcomes of Mini vs Roux-en-Y gastric bypass: A meta-analysis and systematic review.

PubMed

Wang, Fu-Gang; Yan, Wen-Mao; Yan, Ming; Song, Mao-Min

2018-05-10

Mini gastric bypass has been proved to be capable of achieving excellent metabolic results by numerous published studies. Compared to Roux-en-Y gastric bypass, mini gastric bypass is a technically simpler and reversible procedure. However, comparative outcomes of the effectiveness between Mini gastric bypass and Roux-en-Y gastric bypass remain unclear. A systematic literature search was performed in Pubmed, Embase, Cochrane library from inception to February 9, 2018. For assessment of method quality, NOS (Newcastle-Ottawa Scale) and Cochrane Collaboration's tool for assessing risk of bias were used for cohort study and randomized controlled trials, respectively. The meta-analysis was performed by RevMan 5.3 software. 10 cohort studies and 1 randomized controlled trial was included in our meta-analysis. The method quality of the 10 cohort studies was proved as high quality according to the Newcastle-Ottawa Scale. The randomized controlled trial was proved to have a low risk of bias according to Cochrane Collaboration's assessment. Patients receiving mini-gastric bypass had multiple advantageous indexes as compared with patients receiving Roux-en-Y gastric bypass. Examples include: a higher 1-year EWL% (P < 0.05), higher 2-year EWL% (P < 0.05), higher type 2 diabetes mellitus remission rate, as well as a shorter operation time (P < 0.05). No significant statistical difference was observed in hypertension remission rate, mortality, leakage rate, GERD rate, or hospital stay between mini gastric bypass and Roux-en-Y gastric bypass. Mini gastric bypass seems to be a simpler procedure with a better weight reduction effect. This seems to also be the case regarding remission rates of type 2 diabetes mellitus when using Mini gastric bypass in comparison to Roux-en-Y gastric bypass. A small sample size and biased data may have influenced the stability of our results. In light of this, surgeons should treat our results in a conservative way. Larger sample size and multi-center randomized control trials are needed to compare the effectiveness and safety between mini-gastric bypass and Roux-en-Y gastric bypass. Copyright © 2018. Published by Elsevier Ltd.

Review of the development of small- and medium-capacity gas turbines at the Motoren- und Turbinen Union

NASA Technical Reports Server (NTRS)

Heilmann, W.

1985-01-01

Small- and medium-capacity gas turbines under development for turboprop aircraft and helicopter, as well as for armored and commercial vehicle propulsion, are discussed. Design problems related to axial turbines, ceramic components, regenerative gas turbines, and the optimal expansion ratios for turbines with capacities from 250 to greater than 800 kW are considered; in addition, combustion chamber technology is mentioned. Prototype gas turbines with capacities of 500 to 600 kW or 800 to 1800 kW are described.

Experimental Investigation of the Vibration Characteristics of Four Designs of Turbine Blades and of the Effect Produced by Varying the Axial Spacing Between Nozzle Blades and Turbine Blades.

NASA Technical Reports Server (NTRS)

Morgan, W C; Morse, C R

1952-01-01

An investigation was made to determine the effects of varying the spacing between the nozzle blades and the turbine blades of a turbo-jet engine on turbine-blade vibration for four turbine-blade designs of different degrees of stiffness. In general, there was a tendency toward increase in occurrence of vibration with decrease in spacing. The effect was most evident in the case of the turbine blades that had greater stiffness.

Experimental investigation of a supersonic micro turbine running with hexamethyldisiloxane

NASA Astrophysics Data System (ADS)

Weiß Andreas, P.; Josef, Hauer; Tobias, Popp; Markus, Preißinger

2017-09-01

Experimentally determined efficiency characteristics of a supersonic micro turbine are discussed in the present paper. The micro turbine is a representative of a "micro-turbine-generator-construction-kit" for ORC small scale waste heat recovery. The isentropic total-to-static efficiency of the 12 kW turbine reaches an excellent design point performance of 73.4 %. Furthermore, its off-design operating behavior is very advantageous for small waste heat recovery plants: the turbine efficiency keeps a high level over a wide range of pressure ratio and rotational speed.

Turbine-Driven Pipe-Cleaning Brush

NASA Technical Reports Server (NTRS)

Werlink, Rudy J.; Rowell, David E.

1994-01-01

Simple pipe-cleaning device includes small turbine wheel axially connected, by standoff, to circular brush. Turbine wheel turns on hub bearing attached to end of upstream cable. Turbine-and-brush assembly inserted in pipe with cable trailing upstream and brush facing downstream. Water or cleaning solution pumped through pipe. Cable held at upstream end, so it holds turbine and brush in pipe at location to be cleaned. Flow in pipe turns turbine, which turns wheel, producing desired cleaning action. In addition to brushing action, device provides even mixing of cleaning solution in pipe.

Evaluation of Erosion Resistance of Advanced Turbine Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Kuczmarski, Maria A.; Miller, Robert A.; Cuy, Michael D.

2007-01-01

The erosion resistant turbine thermal barrier coating system is critical to aircraft engine performance and durability. By demonstrating advanced turbine material testing capabilities, we will be able to facilitate the critical turbine coating and subcomponent development and help establish advanced erosion-resistant turbine airfoil thermal barrier coatings design tools. The objective of this work is to determine erosion resistance of advanced thermal barrier coating systems under simulated engine erosion and/or thermal gradient environments, validating advanced turbine airfoil thermal barrier coating systems based on nano-tetragonal phase toughening design approaches.

Evaluating the Effectiveness of an Ultrasonic Acoustic Deterrent for Reducing Bat Fatalities at Wind Turbines.

PubMed

Arnett, Edward B; Hein, Cris D; Schirmacher, Michael R; Huso, Manuela M P; Szewczak, Joseph M

2013-01-01

Large numbers of bats are killed by wind turbines worldwide and minimizing fatalities is critically important to bat conservation and acceptance of wind energy development. We implemented a 2-year study testing the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at a wind energy facility in Pennsylvania. We randomly selected control and treatment turbines that were searched daily in summer and fall 2009 and 2010. Estimates of fatality, corrected for field biases, were compared between treatment and control turbines. In 2009, we estimated 21-51% fewer bats were killed per treatment turbine than per control turbine. In 2010, we determined an approximate 9% inherent difference between treatment and control turbines and when factored into our analysis, variation increased and between 2% more and 64% fewer bats were killed per treatment turbine relative to control turbines. We estimated twice as many hoary bats were killed per control turbine than treatment turbine, and nearly twice as many silver-haired bats in 2009. In 2010, although we estimated nearly twice as many hoary bats and nearly 4 times as many silver-haired bats killed per control turbine than at treatment turbines during the treatment period, these only represented an approximate 20% increase in fatality relative to the pre-treatment period for these species when accounting for inherent differences between turbine sets. Our findings suggest broadband ultrasound broadcasts may reduce bat fatalities by discouraging bats from approaching sound sources. However, effectiveness of ultrasonic deterrents is limited by distance and area ultrasound can be broadcast, in part due to rapid attenuation in humid conditions. We caution that an operational deterrent device is not yet available and further modifications and experimentation are needed. Future efforts must also evaluate cost-effectiveness of deterrents in relation to curtailment strategies to allow a cost-benefit analysis for mitigating bat fatalities.

Health Effects Related to Wind Turbine Noise Exposure: A Systematic Review

PubMed Central

Schmidt, Jesper Hvass; Klokker, Mads

2014-01-01

Background Wind turbine noise exposure and suspected health-related effects thereof have attracted substantial attention. Various symptoms such as sleep-related problems, headache, tinnitus and vertigo have been described by subjects suspected of having been exposed to wind turbine noise. Objective This review was conducted systematically with the purpose of identifying any reported associations between wind turbine noise exposure and suspected health-related effects. Data Sources A search of the scientific literature concerning the health-related effects of wind turbine noise was conducted on PubMed, Web of Science, Google Scholar and various other Internet sources. Study Eligibility Criteria All studies investigating suspected health-related outcomes associated with wind turbine noise exposure were included. Results Wind turbines emit noise, including low-frequency noise, which decreases incrementally with increases in distance from the wind turbines. Likewise, evidence of a dose-response relationship between wind turbine noise linked to noise annoyance, sleep disturbance and possibly even psychological distress was present in the literature. Currently, there is no further existing statistically-significant evidence indicating any association between wind turbine noise exposure and tinnitus, hearing loss, vertigo or headache. Limitations Selection bias and information bias of differing magnitudes were found to be present in all current studies investigating wind turbine noise exposure and adverse health effects. Only articles published in English, German or Scandinavian languages were reviewed. Conclusions Exposure to wind turbines does seem to increase the risk of annoyance and self-reported sleep disturbance in a dose-response relationship. There appears, though, to be a tolerable level of around LAeq of 35 dB. Of the many other claimed health effects of wind turbine noise exposure reported in the literature, however, no conclusive evidence could be found. Future studies should focus on investigations aimed at objectively demonstrating whether or not measureable health-related outcomes can be proven to fluctuate depending on exposure to wind turbines. PMID:25474326

Health effects related to wind turbine noise exposure: a systematic review.

PubMed

Schmidt, Jesper Hvass; Klokker, Mads

2014-01-01

Wind turbine noise exposure and suspected health-related effects thereof have attracted substantial attention. Various symptoms such as sleep-related problems, headache, tinnitus and vertigo have been described by subjects suspected of having been exposed to wind turbine noise. This review was conducted systematically with the purpose of identifying any reported associations between wind turbine noise exposure and suspected health-related effects. A search of the scientific literature concerning the health-related effects of wind turbine noise was conducted on PubMed, Web of Science, Google Scholar and various other Internet sources. All studies investigating suspected health-related outcomes associated with wind turbine noise exposure were included. Wind turbines emit noise, including low-frequency noise, which decreases incrementally with increases in distance from the wind turbines. Likewise, evidence of a dose-response relationship between wind turbine noise linked to noise annoyance, sleep disturbance and possibly even psychological distress was present in the literature. Currently, there is no further existing statistically-significant evidence indicating any association between wind turbine noise exposure and tinnitus, hearing loss, vertigo or headache. Selection bias and information bias of differing magnitudes were found to be present in all current studies investigating wind turbine noise exposure and adverse health effects. Only articles published in English, German or Scandinavian languages were reviewed. Exposure to wind turbines does seem to increase the risk of annoyance and self-reported sleep disturbance in a dose-response relationship. There appears, though, to be a tolerable level of around LAeq of 35 dB. Of the many other claimed health effects of wind turbine noise exposure reported in the literature, however, no conclusive evidence could be found. Future studies should focus on investigations aimed at objectively demonstrating whether or not measureable health-related outcomes can be proven to fluctuate depending on exposure to wind turbines.

Evaluating the Effectiveness of an Ultrasonic Acoustic Deterrent for Reducing Bat Fatalities at Wind Turbines

PubMed Central

Arnett, Edward B.; Hein, Cris D.; Schirmacher, Michael R.; Huso, Manuela M. P.; Szewczak, Joseph M.

2013-01-01

Large numbers of bats are killed by wind turbines worldwide and minimizing fatalities is critically important to bat conservation and acceptance of wind energy development. We implemented a 2-year study testing the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at a wind energy facility in Pennsylvania. We randomly selected control and treatment turbines that were searched daily in summer and fall 2009 and 2010. Estimates of fatality, corrected for field biases, were compared between treatment and control turbines. In 2009, we estimated 21–51% fewer bats were killed per treatment turbine than per control turbine. In 2010, we determined an approximate 9% inherent difference between treatment and control turbines and when factored into our analysis, variation increased and between 2% more and 64% fewer bats were killed per treatment turbine relative to control turbines. We estimated twice as many hoary bats were killed per control turbine than treatment turbine, and nearly twice as many silver-haired bats in 2009. In 2010, although we estimated nearly twice as many hoary bats and nearly 4 times as many silver-haired bats killed per control turbine than at treatment turbines during the treatment period, these only represented an approximate 20% increase in fatality relative to the pre-treatment period for these species when accounting for inherent differences between turbine sets. Our findings suggest broadband ultrasound broadcasts may reduce bat fatalities by discouraging bats from approaching sound sources. However, effectiveness of ultrasonic deterrents is limited by distance and area ultrasound can be broadcast, in part due to rapid attenuation in humid conditions. We caution that an operational deterrent device is not yet available and further modifications and experimentation are needed. Future efforts must also evaluate cost-effectiveness of deterrents in relation to curtailment strategies to allow a cost-benefit analysis for mitigating bat fatalities. PMID:23840369

Simulations of an Offshore Wind Farm Using Large-Eddy Simulation and a Torque-Controlled Actuator Disc Model

NASA Astrophysics Data System (ADS)

Creech, Angus; Früh, Wolf-Gerrit; Maguire, A. Eoghan

2015-05-01

We present here a computational fluid dynamics (CFD) simulation of Lillgrund offshore wind farm, which is located in the Øresund Strait between Sweden and Denmark. The simulation combines a dynamic representation of wind turbines embedded within a large-eddy simulation CFD solver and uses hr-adaptive meshing to increase or decrease mesh resolution where required. This allows the resolution of both large-scale flow structures around the wind farm, and the local flow conditions at individual turbines; consequently, the response of each turbine to local conditions can be modelled, as well as the resulting evolution of the turbine wakes. This paper provides a detailed description of the turbine model which simulates the interaction between the wind, the turbine rotors, and the turbine generators by calculating the forces on the rotor, the body forces on the air, and instantaneous power output. This model was used to investigate a selection of key wind speeds and directions, investigating cases where a row of turbines would be fully aligned with the wind or at specific angles to the wind. Results shown here include presentations of the spin-up of turbines, the observation of eddies moving through the turbine array, meandering turbine wakes, and an extensive wind farm wake several kilometres in length. The key measurement available for cross-validation with operational wind farm data is the power output from the individual turbines, where the effect of unsteady turbine wakes on the performance of downstream turbines was a main point of interest. The results from the simulations were compared to the performance measurements from the real wind farm to provide a firm quantitative validation of this methodology. Having achieved good agreement between the model results and actual wind farm measurements, the potential of the methodology to provide a tool for further investigations of engineering and atmospheric science problems is outlined.

Evaluating the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at wind turbines

USGS Publications Warehouse

Arnett, Edward B.; Hein, Cris D.; Schirmacher, Michael R.; Huso, Manuela M.P.; Szewczak, Joseph M.

2013-01-01

Large numbers of bats are killed by wind turbines worldwide and minimizing fatalities is critically important to bat conservation and acceptance of wind energy development. We implemented a 2-year study testing the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at a wind energy facility in Pennsylvania. We randomly selected control and treatment turbines that were searched daily in summer and fall 2009 and 2010. Estimates of fatality, corrected for field biases, were compared between treatment and control turbines. In 2009, we estimated 21–51% fewer bats were killed per treatment turbine than per control turbine. In 2010, we determined an approximate 9% inherent difference between treatment and control turbines and when factored into our analysis, variation increased and between 2% more and 64% fewer bats were killed per treatment turbine relative to control turbines. We estimated twice as many hoary bats were killed per control turbine than treatment turbine, and nearly twice as many silver-haired bats in 2009. In 2010, although we estimated nearly twice as many hoary bats and nearly 4 times as many silver-haired bats killed per control turbine than at treatment turbines during the treatment period, these only represented an approximate 20% increase in fatality relative to the pre-treatment period for these species when accounting for inherent differences between turbine sets. Our findings suggest broadband ultrasound broadcasts may reduce bat fatalities by discouraging bats from approaching sound sources. However, effectiveness of ultrasonic deterrents is limited by distance and area ultrasound can be broadcast, in part due to rapid attenuation in humid conditions. We caution that an operational deterrent device is not yet available and further modifications and experimentation are needed. Future efforts must also evaluate cost-effectiveness of deterrents in relation to curtailment strategies to allow a cost-benefit analysis for mitigating bat fatalities.

Coalescing Wind Turbine Wakes

DOE PAGES

Lee, S.; Churchfield, M.; Sirnivas, S.; ...

2015-06-18

A team of researchers from the National Renewable Energy Laboratory and Statoil used large-eddy simulations to numerically investigate the merging wakes from upstream offshore wind turbines. Merging wakes are typical phenomena in wind farm flows in which neighboring turbine wakes consolidate to form complex flow patterns that are as yet not well understood. In the present study, three 6-MW turbines in a row were subjected to a neutrally stable atmospheric boundary layer flow. As a result, the wake from the farthest upstream turbine conjoined the downstream wake, which significantly altered the subsequent velocity deficit structures, turbulence intensity, and the globalmore » meandering behavior. The complexity increased even more when the combined wakes from the two upstream turbines mixed with the wake generated by the last turbine, thereby forming a "triplet" structure. Although the influence of the wake generated by the first turbine decayed with downstream distance, the mutated wakes from the second turbine continued to influence the downstream wake. Two mirror-image angles of wind directions that yielded partial wakes impinging on the downstream turbines yielded asymmetric wake profiles that could be attributed to the changing flow directions in the rotor plane induced by the Coriolis force. In conclusion, the turbine wakes persisted for extended distances in the present study, which is a result of low aerodynamic surface roughness typically found in offshore conditions« less

Scanning of wind turbine upwind conditions: numerical algorithm and first applications

NASA Astrophysics Data System (ADS)

Calaf, Marc; Cortina, Gerard; Sharma, Varun; Parlange, Marc B.

2014-11-01

Wind turbines still obtain in-situ meteorological information by means of traditional wind vane and cup anemometers installed at the turbine's nacelle, right behind the blades. This has two important drawbacks: 1-turbine misalignment with the mean wind direction is common and energy losses are experienced; 2-the near-blade monitoring does not provide any time to readjust the profile of the wind turbine to incoming turbulence gusts. A solution is to install wind Lidar devices on the turbine's nacelle. This technique is currently under development as an alternative to traditional in-situ wind anemometry because it can measure the wind vector at substantial distances upwind. However, at what upwind distance should they interrogate the atmosphere? A new flexible wind turbine algorithm for large eddy simulations of wind farms that allows answering this question, will be presented. The new wind turbine algorithm timely corrects the turbines' yaw misalignment with the changing wind. The upwind scanning flexibility of the algorithm also allows to track the wind vector and turbulent kinetic energy as they approach the wind turbine's rotor blades. Results will illustrate the spatiotemporal evolution of the wind vector and the turbulent kinetic energy as the incoming flow approaches the wind turbine under different atmospheric stability conditions. Results will also show that the available atmospheric wind power is larger during daytime periods at the cost of an increased variance.

Mod-0A Wind Turbine in Block Island, Rhode Island

NASA Image and Video Library

1979-06-21

A Mod-0A 200-kilowatt wind turbine designed by National Aeronautics and Space Administration (NASA) Lewis Research Center and constructed in Block Island, Rhode Island. The wind turbine program was a joint program between NASA and the Energy Research and Development Administration (ERDA) during the 1970s to develop less expensive forms of energy. NASA Lewis was assigned the responsibility of developing large horizontal-axis wind turbines. The program included a series of increasingly powerful wind turbines, designated: Mod-0A, Mod-1, WTS-4, and Mod-5. The program’s first device was a Mod-0 100-kilowatt wind turbine test bed at NASA’s Plum Brook Station. This Mod-0A 200-kilowatt turbine, completed in 1977, was the program’s second-generation device. It included a 125-foot diameter blade atop a 100-foot tall tower. This early wind turbine was designed determine its operating problems, integrate with the local utilities, and assess the attitude of the local community. There were additional Mod-0A turbines built in Culebra, Puerto Rico; Clayton, New Mexico; and Oahu, Hawaii. The Mod-0A turbines suffered durability issues with the rotor blade and initially appeared unreliable. NASA engineers addressed the problems, and the turbines proved to be reliable and efficient devices that operated for a number of years. The information gained from these early models was vital to the design and improvement of the later generations.

Simulation-Based Approach for Site-Specific Optimization of Hydrokinetic Turbine Arrays

NASA Astrophysics Data System (ADS)

Sotiropoulos, F.; Chawdhary, S.; Yang, X.; Khosronejad, A.; Angelidis, D.

2014-12-01

A simulation-based approach has been developed to enable site-specific optimization of tidal and current turbine arrays in real-life waterways. The computational code is based on the St. Anthony Falls Laboratory Virtual StreamLab (VSL3D), which is able to carry out high-fidelity simulations of turbulent flow and sediment transport processes in rivers and streams taking into account the arbitrary geometrical complexity characterizing natural waterways. The computational framework can be used either in turbine-resolving mode, to take into account all geometrical details of the turbine, or with the turbines parameterized as actuator disks or actuator lines. Locally refined grids are employed to dramatically increase the resolution of the simulation and enable efficient simulations of multi-turbine arrays. Turbine/sediment interactions are simulated using the coupled hydro-morphodynamic module of VSL3D. The predictive capabilities of the resulting computational framework will be demonstrated by applying it to simulate turbulent flow past a tri-frame configuration of hydrokinetic turbines in a rigid-bed turbulent open channel flow as well as turbines mounted on mobile bed open channels to investigate turbine/sediment interactions. The utility of the simulation-based approach for guiding the optimal development of turbine arrays in real-life waterways will also be discussed and demonstrated. This work was supported by NSF grant IIP-1318201. Simulations were carried out at the Minnesota Supercomputing Institute.

PIV study of the wake of a model wind turbine transitioning between operating set points

NASA Astrophysics Data System (ADS)

Houck, Dan; Cowen, Edwin (Todd)

2016-11-01

Wind turbines are ideally operated at their most efficient tip speed ratio for a given wind speed. There is increasing interest, however, in operating turbines at other set points to increase the overall power production of a wind farm. Specifically, Goit and Meyers (2015) used LES to examine a wind farm optimized by unsteady operation of its turbines. In this study, the wake of a model wind turbine is measured in a water channel using PIV. We measure the wake response to a change in operational set point of the model turbine, e.g., from low to high tip speed ratio or vice versa, to examine how it might influence a downwind turbine. A modified torque transducer after Kang et al. (2010) is used to calibrate in situ voltage measurements of the model turbine's generator operating across a resistance to the torque on the generator. Changes in operational set point are made by changing the resistance or the flow speed, which change the rotation rate measured by an encoder. Single camera PIV on vertical planes reveals statistics of the wake at various distances downstream as the turbine transitions from one set point to another. From these measurements, we infer how the unsteady operation of a turbine may affect the performance of a downwind turbine as its incoming flow. National Science Foundation and the Atkinson Center for a Sustainable Future.

Suitability of electronic mini-boluses for the early identification of goat kids and effects on growth performance and development of the reticulorumen.

PubMed

Castro, N; Martín, D; Castro-Alonso, A; Argüello, A; Capote, J; Caja, G

2010-10-01

A total of 60 twin-goat kids (30 male and 30 female) of the Canary Island Majorera dairy breed were used in 2 experiments to evaluate 2 types of electronic identification mini-boluses and their effects on rearing performances and reticulorumen development. Electronic identification mini-boluses were cylindrical and made of ceramic materials (B1, 9.0 g and 38.5 × 9.5 mm; B2, 16.3 g and 42.2 × 12.2 mm), contained a 32-mm half-duplex passive transponder, and were administered to kids at different BW. In Exp. 1, treatments were 1) control, without bolus (n = 15) and 2) identified with B1 at 4.8 kg of BW (n = 15). In Exp. 2, treatments were 1) control, without bolus (n = 15) and 2) identified with B2 at 5.6 kg of BW (n = 15). Kids were penned separately, according to mini-bolus treatments, fed a milk replacer daily, and slaughtered at 10 kg of BW. Milk replacer intake was recorded individually twice weekly and boluses read weekly until slaughter. The full and empty stomach complex was measured immediately after slaughter, and mini-bolus location was recorded. Samples of the reticulum and rumen wall were taken to measure the number and length of the papillae and crest. Despite the light BW of kids at time of mini-bolus treatment, no negative effects (P > 0.05) of B1 and B2 mini-boluses were observed on milk intake, growth rate, or G:F in either experiment. No kid mortality or mini-bolus losses were observed during either experiment. All mini-boluses were retained until slaughter, and all were found in the rumen upon dissection, except one B2, which was found in the reticulum. Mini-bolus treatment did not affect (P > 0.05) the weight of full and empty reticulorumen or the number of papillae and crest size of the reticulum epithelium. Moreover, the B1-treated kids showed a greater number of papillae in the rumen wall than the control kids (22.4 +/- 1.0 vs. 18.9 +/- 0.9 papillae/cm, respectively; P < 0.05) in Exp. 1. In conclusion, the use of mini-boluses was suitable for the electronic identification of growing kids from early ages (wk 2 to 5 of age and 5 to 6 kg of BW) and did not produce negative effects on their growth performances or on reticulorumen development. These results support the use of properly designed boluses as a unique identification device for the entire lifespan of goats.

76. TURBINE HALL, UNIT 2 SHOWING BOTH TURBINE AND CONDENSER ...

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

76. TURBINE HALL, UNIT 2 SHOWING BOTH TURBINE AND CONDENSER (SEE ALSO, DRAWING No. 12 OF 13) - Delaware County Electric Company, Chester Station, Delaware River at South end of Ward Street, Chester, Delaware County, PA

Smoother Turbine Blades Resist Thermal Shock Better

NASA Technical Reports Server (NTRS)

Czerniak, Paul; Longenecker, Kent; Paulus, Don; Ullman, Zane

1991-01-01

Surface treatment increases resistance of turbine blades to low-cycle fatigue. Smoothing removes small flaws where cracks start. Intended for blades in turbines subject to thermal shock of rapid starting. No recrystallization occurs at rocket-turbine operating temperatures.

Cost/benefit analysis of advanced material technologies for small aircraft turbine engines

NASA Technical Reports Server (NTRS)

Comey, D. H.

1977-01-01

Cost/benefit studies were conducted on ten advanced material technologies applicable to small aircraft gas turbine engines to be produced in the 1985 time frame. The cost/benefit studies were applied to a two engine, business-type jet aircraft in the 6800- to 9100-Kg (15,000- to 20,000-lb) gross weight class. The new material technologies are intended to provide improvements in the areas of high-pressure turbine rotor components, high-pressure turbine rotor components, high-pressure turbine stator airfoils, and static structural components. The cost/benefit of each technology is presented in terms of relative value, which is defined as a change in life cycle cost times probability of success divided by development cost. Technologies showing the most promising cost/benefits based on relative value are uncooled single crystal MAR-M 247 turbine blades, cooled DS MAR-M 247 turbine blades, and cooled ODS 'M'CrAl laminate turbine stator vanes.

Advanced technology cogeneration system conceptual design study: Closed cycle gas turbines

NASA Technical Reports Server (NTRS)

Mock, E. A. T.; Daudet, H. C.

1983-01-01

The results of a three task study performed for the Department of Energy under the direction of the NASA Lewis Research Center are documented. The thermal and electrical energy requirements of three specific industrial plants were surveyed and cost records for the energies consumed were compiled. Preliminary coal fired atmospheric fluidized bed heated closed cycle gas turbine and steam turbine cogeneration system designs were developed for each industrial plant. Preliminary cost and return-on-equity values were calculated and the results compared. The best of the three sites was selected for more detailed design and evaluation of both closed cycle gas turbine and steam turbine cogeneration systems during Task II. Task III involved characterizing the industrial sector electrical and thermal loads for the 48 contiguous states, applying a family of closed cycle gas turbine and steam turbine cogeneration systems to these loads, and conducting a market penetration analysis of the closed cycle gas turbine cogeneration system.

Aerodynamic Interactions between Pairs of Vertical-Axis Wind Turbines

NASA Astrophysics Data System (ADS)

Brownstein, Ian; Dabiri, John

2017-11-01

Increased power production has been observed in downstream vertical-axis wind turbines (VAWTs) when positioned offset from the wake of upstream turbines. This effect was found to exist in both laboratory and field environments with pairs of co- and counter-rotating turbines. It is hypothesized that the observed power production enhancement is due to flow acceleration adjacent to the upstream turbine caused by bluff body blockage, which increases the incident freestream velocity on appropriately positioned downstream turbines. This type of flow acceleration has been observed in computational and laboratory studies of VAWTs and will be further investigated here using 3D-PTV measurements around pairs of laboratory-scale VAWTs. These measurements will be used to understand the mechanisms behind the performance enhancement effect and seek to determine optimal separation distances and angles between turbines based on turbine design parameters. These results will lead to recommendations for optimizing the power production of VAWT wind farms which utilize this effect.

Microfabricated rankine cycle steam turbine for power generation and methods of making the same

NASA Technical Reports Server (NTRS)

Muller, Norbert (Inventor); Lee, Changgu (Inventor); Frechette, Luc (Inventor)

2009-01-01

In accordance with the present invention, an integrated micro steam turbine power plant on-a-chip has been provided. The integrated micro steam turbine power plant on-a-chip of the present invention comprises a miniature electric power generation system fabricated using silicon microfabrication technology and lithographic patterning. The present invention converts heat to electricity by implementing a thermodynamic power cycle on a chip. The steam turbine power plant on-a-chip generally comprises a turbine, a pump, an electric generator, an evaporator, and a condenser. The turbine is formed by a rotatable, disk-shaped rotor having a plurality of rotor blades disposed thereon and a plurality of stator blades. The plurality of stator blades are interdigitated with the plurality of rotor blades to form the turbine. The generator is driven by the turbine and converts mechanical energy into electrical energy.

Cold flow testing of the Space Shuttle Main Engine high pressure fuel turbine model

NASA Technical Reports Server (NTRS)

Hudson, Susan T.; Gaddis, Stephen W.; Johnson, P. D.; Boynton, James L.

1991-01-01

In order to experimentally determine the performance of the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) turbine, a 'cold' air flow turbine test program was established at NASA's Marshall Space Flight Center. As part of this test program, a baseline test of Rocketdyne's HPFTP turbine has been completed. The turbine performance and turbine diagnostics such as airfoil surface static pressure distributions, static pressure drops through the turbine, and exit swirl angles were investigated at the turbine design point, over its operating range, and at extreme off-design points. The data was compared to pretest predictions with good results. The test data has been used to improve meanline prediction codes and is now being used to validate various three-dimensional codes. The data will also be scaled to engine conditions and used to improve the SSME steady-state performance model.

CFD Aided Design and Production of Hydraulic Turbines

NASA Astrophysics Data System (ADS)

Kaplan, Alper; Cetinturk, Huseyin; Demirel, Gizem; Ayli, Ece; Celebioglu, Kutay; Aradag, Selin; ETU Hydro Research Center Team

2014-11-01

Hydraulic turbines are turbo machines which produce electricity from hydraulic energy. Francis type turbines are the most common one in use today. The design of these turbines requires high engineering effort since each turbine is tailor made due to different head and discharge. Therefore each component of the turbine is designed specifically. During the last decades, Computational Fluid Dynamics (CFD) has become very useful tool to predict hydraulic machinery performance and save time and money for designers. This paper describes a design methodology to optimize a Francis turbine by integrating theoretical and experimental fundamentals of hydraulic machines and commercial CFD codes. Specific turbines are designed and manufactured with the help of a collaborative CFD/CAD/CAM methodology based on computational fluid dynamics and five-axis machining for hydraulic electric power plants. The details are presented in this study. This study is financially supported by Turkish Ministry of Development.

Simulation Comparison of Wake Mitigation Control Strategies for a Two-Turbine Case

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

Fleming, Paul; Gebraad, Pieter M. O.; Lee, Sang

2015-12-01

Wind turbines arranged in a wind plant impact each other through their wakes. Wind plant control is an active research field that attempts to improve wind plant performance by coordinating control of individual turbines to take into account these turbine–wake interactions. High-fidelity simulations of a two-turbine fully waked scenario are used to investigate several wake mitigation strategies, in this paper, including modification of yaw and tilt angles of an upstream turbine to induce wake skew, as well as repositioning of the downstream turbine. The simulation results are compared through change relative to a baseline operation in terms of overall powermore » capture and loading on the upstream and downstream turbine. Results demonstrated improved power production for all methods. Moreover, analysis of control options, including individual pitch control, shows potential to minimize the increase of, or even reduce, turbine loads.« less

Comparison of damage to live v. euthanized Atlantic salmon Salmo salar smolts from passage through an Archimedean screw turbine.

PubMed

Brackley, R; Lucas, M C; Thomas, R; Adams, C E; Bean, C W

2018-05-01

This study assessed the usefulness of passing euthanized Atlantic salmon Salmo salar smolts through an Archimedean screw turbine to test for external damage, as compared with live, actively swimming smolts. Scale loss was the only observed effect. Severe scale loss was 5·9 times more prevalent in euthanized turbine-passed fish (45%) than the live fish (7·6%). Additionally, distinctive patterns of scale loss, consistent with grinding between the turbine helices and housing trough, were observed in 35% of euthanized turbine-passed smolts. This distinctive pattern of scale loss was not seen in live turbine-passed smolts, nor in control groups (live and euthanized smolts released downstream of the turbine), which suggests that the altered behaviour of dead fish in turbine flows generates biased injury outcomes. © 2018 The Fisheries Society of the British Isles.

Thermal stresses investigation of a gas turbine blade

NASA Astrophysics Data System (ADS)

Gowreesh, S.; Pravin, V. K.; Rajagopal, K.; Veena, P. H.

2012-06-01

The analysis of structural and thermal stress values that are produced while the turbine is operating are the key factors of study while designing the next generation gas turbines. The present study examines structural, thermal, modal analysis of the first stage rotor blade of a two stage gas turbine. The design features of the turbine segment of the gas turbine have been taken from the preliminary design of a power turbine for maximization of an existing turbojet engine with optimized dump gap of the combustion chamber, since the allowable temperature on the turbine blade dependents on the hot gas temperatures from the combustion chamber. In the present paper simplified 3-D Finite Element models are developed with governing boundary conditions and solved using the commercial FEA software ANSYS. As the temperature has a significant effect on the overall stress on the rotor blades, a detail study on mechanical and thermal stresses are estimated and evaluated with the experimental values.

Effects of setting angle and chord length on performance of four blades bionic wind turbine

NASA Astrophysics Data System (ADS)

Yang, Z. X.; Li, G. S.; Song, L.; Bai, Y. F.

2017-11-01

With the energy crisis and the increasing environmental pollution, more and more efforts have been made about wind power development. In this paper, a four blades bionic wind turbine was proposed, and the outline of wind turbine was constructed by the fitted curve. This paper attempted to research the effects of setting angle and chord length on performance of four blades bionic wind turbine by computational fluid dynamics (CFD) simulation. The results showed that the setting angle and chord length of the bionic wind turbine has some significant effects on the efficiency of the wind turbine, and within the range of wind speed from 7 m/s to 15 m/s, the wind turbine achieved maximum efficiency when the setting angle is 31 degree and the chord length is 125 mm. The conclusion will work as a guideline for the improvement of wind turbine design

An analytic approach to optimize tidal turbine fields

NASA Astrophysics Data System (ADS)

Pelz, P.; Metzler, M.

2013-12-01

Motivated by global warming due to CO2-emission various technologies for harvesting of energy from renewable sources are developed. Hydrokinetic turbines get applied to surface watercourse or tidal flow to gain electrical energy. Since the available power for hydrokinetic turbines is proportional to the projected cross section area, fields of turbines are installed to scale shaft power. Each hydrokinetic turbine of a field can be considered as a disk actuator. In [1], the first author derives the optimal operation point for hydropower in an open-channel. The present paper concerns about a 0-dimensional model of a disk-actuator in an open-channel flow with bypass, as a special case of [1]. Based on the energy equation, the continuity equation and the momentum balance an analytical approach is made to calculate the coefficient of performance for hydrokinetic turbines with bypass flow as function of the turbine head and the ratio of turbine width to channel width.

Cold-air performance of a 15.41-cm-tip-diameter axial-flow power turbine with variable-area stator designed for a 75-kW automotive gas turbine engine

NASA Technical Reports Server (NTRS)

Mclallin, K. L.; Kofskey, M. G.; Wong, R. Y.

1982-01-01

An experimental evaluation of the aerodynamic performance of the axial flow, variable area stator power turbine stage for the Department of Energy upgraded automotive gas turbine engine was conducted in cold air. The interstage transition duct, the variable area stator, the rotor, and the exit diffuser were included in the evaluation of the turbine stage. The measured total blading efficiency was 0.096 less than the design value of 0.85. Large radial gradients in flow conditions were found at the exit of the interstage duct that adversely affected power turbine performance. Although power turbine efficiency was less than design, the turbine operating line corresponding to the steady state road load power curve was within 0.02 of the maximum available stage efficiency at any given speed.

Performance analysis of mini-propellers based on FlightGear

NASA Astrophysics Data System (ADS)

Vogeltanz, Tomáš

2016-06-01

This paper presents a performance analysis of three mini-propellers based on the FlightGear flight simulator. Although a basic propeller analysis has to be performed before the use of FlightGear, for a complex and more practical performance analysis, it is advantageous to use a propeller model in cooperation with a particular aircraft model. This approach may determine whether the propeller has sufficient quality in respect of aircraft requirements. In the first section, the software used for the analysis is illustrated. Then, the parameters of the analyzed mini-propellers and the tested UAV are described. Finally, the main section shows and discusses the results of the performance analysis of the mini-propellers.

Concentrating Solar Power Projects - Guzmán | Concentrating Solar Power |

Science.gov Websites

) Owner(s): FCC Energy (70%) Mitsui (30%) Technology: Parabolic trough Turbine Capacity: Net: 50.0 MW -Field Outlet Temp: 393°C Solar-Field Temp Difference: 100°C Power Block Turbine Capacity (Gross): 50.0 MW Turbine Capacity (Net): 50.0 MW Turbine Manufacturer: Man-Turbo Turbine Description: 5 extractions

30. VIEW DOWN INTO TURBINE PIT SHOWING WICKET GATE CONTROL ...

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

30. VIEW DOWN INTO TURBINE PIT SHOWING WICKET GATE CONTROL MECHANISM AND MAIN SHAFT OF I. P. MORRIS TURBINE. TURBINE BUILT BY I. P. MORRIS & DE LA VERGNE, INC. OF PHILADELPHIA, PA, AND INSTALLED IN 1925. TURBINE RATED AT 18,000 HP AT 113.3 RPM UNDER 18.5 FEET OF HEAD. - Lake Lynn Hydroelectric Power House & Dam, Cheat River, Morgantown, Monongalia County, WV

Materials for Wind Turbine Blades: An Overview

PubMed Central

Branner, Kim; Petersen, Helga Nørgaard; Beauson, Justine; McGugan, Malcolm; Sørensen, Bent F.

2017-01-01

A short overview of composite materials for wind turbine applications is presented here. Requirements toward the wind turbine materials, loads, as well as available materials are reviewed. Apart from the traditional composites for wind turbine blades (glass fibers/epoxy matrix composites), natural composites, hybrid and nanoengineered composites are discussed. Manufacturing technologies for wind turbine composites, as well their testing and modelling approaches are reviewed. PMID:29120396

Wind Energy Modeling and Simulation | Wind | NREL

Science.gov Websites

Wind Energy Modeling and Simulation Wind Turbine Modeling and Simulation Wind turbines are unique wind turbines. It enables the analysis of a range of wind turbine configurations, including: Two- or (SOWFA) employs computational fluid dynamics to allow users to investigate wind turbine and wind power

First International Workshop on Grid Simulator Testing of Wind Turbine

Science.gov Websites

of Wind Turbine Drivetrains First International Workshop on Grid Simulator Testing of Wind Turbine Wind Turbine Drivetrains June 13-14, 2013, at the National Wind Technology Center near Boulder apparatuses involved in grid compliance testing of utility-scale wind turbine generators. This includes both

Radar Cross Section (RCS) Simulation for Wind Turbines

DTIC Science & Technology

2013-06-01

SECTION (RCS) SIMULATION FOR WIND TURBINES by Cuong Ton June 2013 Thesis Advisor: David C. Jenn Second Reader: Ric Romero THIS PAGE...TITLE AND SUBTITLE RADAR CROSS SECTION (RCS) SIMULATION FOR WIND TURBINES 5. FUNDING NUMBERS 6. AUTHOR(S) Cuong Ton 7. PERFORMING ORGANIZATION...ABSTRACT (maximum 200 words) Wind - turbine power provides energy-independence and greenhouse-gas reduction benefits, but if wind turbines are built

Analysis of the Challenges and Opportunities of Hydrokinetic Turbine Development Affecting the US Army Corps of Engineers

DTIC Science & Technology

2014-08-01

Hydrokinetic Turbine Development Affecting the US Army Corps of Engineers by David L. Smith, John M. Nestler, Richard Styles, and Brian Tetreault BACKGROUND...attendant environmental impacts. One family of renewable energy technologies experiencing increased national interest is hydrokinetic turbines ...Hydrokinetic turbines include systems that convert waves, tides, and river flow (without impoundment) into electric energy. River hydrokinetic turbines

An overview of aerospace gas turbine technology of relevance to the development of the automotive gas turbine engine

NASA Technical Reports Server (NTRS)

Evans, D. G.; Miller, T. J.

1978-01-01

Technology areas related to gas turbine propulsion systems with potential for application to the automotive gas turbine engine are discussed. Areas included are: system steady-state and transient performance prediction techniques, compressor and turbine design and performance prediction programs and effects of geometry, combustor technology and advanced concepts, and ceramic coatings and materials technology.

77 FR 40479 - Airworthiness Directives; Rolls-Royce Corporation Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-10

... inspection (FPI) on certain 3rd and 4th stage turbine wheels for cracks in the turbine blades. We are issuing this AD to prevent failure of 3rd or 4th stage turbine wheel blades which could cause engine failure... certain 3rd and 4th stage turbine wheels for cracks in the turbine blades. Comments We gave the public the...

Understanding Trends in Wind Turbine Prices Over the Past Decade

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

Bolinger, Mark; Wiser, Ryan

Taking a bottom-up approach, this report examines seven primary drivers of wind turbine prices in the United States, with the goal of estimating the degree to which each contributed to the doubling in turbine prices from 2002 through 2008, as well as the subsequent decline in prices through 2010 (our analysis does not extend into 2011 because several of these drivers are best gauged on a full-year basis due to seasonality issues). The first four of these drivers can be considered, at least to some degree, endogenous influences – i.e., those that are largely within the control of the windmore » industry – and include changes in: 1) Labor costs, which have historically risen during times of tight turbine supply; 2) Warranty provisions, which reflect technology performance and reliability, and are most often capitalized in turbine prices; 3) Turbine manufacturer profitability, which can impact turbine prices independently of costs; and 4) Turbine design, which for the purpose of this analysis is principally manifested through increased turbine size. The other three drivers analyzed in this study can be considered exogenous influences, in that they can impact wind turbine costs but fall mostly outside of the direct control of the wind industry. These exogenous drivers include changes in: 5) Raw materials prices, which affect the cost of inputs to the manufacturing process; 6) Energy prices, which impact the cost of manufacturing and transporting turbines; and 7) Foreign exchange rates, which can impact the dollar amount paid for turbines and components imported into the United States.« less

Causes of bat fatalities at wind turbines: Hypotheses and predictions

USGS Publications Warehouse

Cryan, P.M.; Barclay, R.M.R.

2009-01-01

Thousands of industrial-scale wind turbines are being built across the world each year to meet the growing demand for sustainable energy. Bats of certain species are dying at wind turbines in unprecedented numbers. Species of bats consistently affected by turbines tend to be those that rely on trees as roosts and most migrate long distances. Although considerable progress has been made in recent years toward better understanding the problem, the causes of bat fatalities at turbines remain unclear. In this synthesis, we review hypothesized causes of bat fatalities at turbines. Hypotheses of cause fall into 2 general categoriesproximate and ultimate. Proximate causes explain the direct means by which bats die at turbines and include collision with towers and rotating blades, and barotrauma. Ultimate causes explain why bats come close to turbines and include 3 general types: random collisions, coincidental collisions, and collisions that result from attraction of bats to turbines. The random collision hypothesis posits that interactions between bats and turbines are random events and that fatalities are representative of the bats present at a site. Coincidental hypotheses posit that certain aspects of bat distribution or behavior put them at risk of collision and include aggregation during migration and seasonal increases in flight activity associated with feeding or mating. A surprising number of attraction hypotheses suggest that bats might be attracted to turbines out of curiosity, misperception, or as potential feeding, roosting, flocking, and mating opportunities. Identifying, prioritizing, and testing hypothesized causes of bat collisions with wind turbines are vital steps toward developing practical solutions to the problem. ?? 2009 American Society of Mammalogists.

Ceramic blade attachment system

DOEpatents

Shaffer, J.E.

1995-01-10

A turbine blade having a preestablished rate of thermal expansion is attached to a turbine wheel having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine blade. The turbine blade has a root portion having a first groove and a second groove therein. The turbine wheel includes a plurality of openings in which the turbine blade is positioned. Each of the openings has a first groove and a second groove therein. The space or void formed between the first grooves and the second grooves has a plurality of spherical balls positioned therein. The plurality of spherical balls has a preestablished rate of thermal expansion being equal to the preestablished rate of thermal expansion of the turbine blade. 4 figures.

Ceramic blade attachment system

DOEpatents

Shaffer, James E.

1995-01-01

A turbine blade having a preestablished rate of thermal expansion is attached to a turbine wheel having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine blade. The turbine blade has a root portion having a first groove and a second groove therein. The turbine wheel includes a plurality of openings in which the turbine blade is positioned. Each of the openings has a first groove and a second groove therein. The space or void formed between the first grooves and the second grooves has a plurality of spherical balls positioned therein. The plurality of spherical balls has a preestablished rate of thermal expansion being equal to the preestablished rate of thermal expansion of the turbine blade.

40. VIEW OF TURBINE HALL LOOKING SOUTHWEST AT WESTINGHOUSEPARSONS TURBINE ...

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

40. VIEW OF TURBINE HALL LOOKING SOUTHWEST AT WESTINGHOUSE-PARSONS TURBINE NUMBER 2. THIS UNIT WAS INSTALLED IN 1925. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

77 FR 3514 - Protection Against Turbine Missiles

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-24

... NUCLEAR REGULATORY COMMISSION [NRC-2009-0481] Protection Against Turbine Missiles AGENCY: Nuclear... (NRC or Commission) is issuing a revision to Regulatory Guide 1.115, ``Protection Against Turbine... structures, systems, and components against missiles resulting from turbine failure by the appropriate...

Mapping lightning in the sky with a mini array

NASA Astrophysics Data System (ADS)

Füllekrug, Martin; Liu, Zhongjian; Koh, Kuang; Mezentsev, Andrew; Pedeboy, Stéphane; Soula, Serge; Enno, Sven-Erik; Sugier, Jacqueline; Rycroft, Michael J.

2016-10-01

Mini arrays are commonly used for infrasonic and seismic studies. Here we report for the first time the detection and mapping of distant lightning discharges in the sky with a mini array. The array has a baseline to wavelength ratio ˜4.2·10-2 to record very low frequency electromagnetic waves from 2 to 18 kHz. It is found that the mini array detects ˜69 lightning pulses per second from cloud-to-ground and in-cloud discharges, even though the parent thunderstorms are ˜900-1100 km away and a rigorous selection criterion based on the quality of the wavefront across the array is used. In particular, lightning pulses that exhibit a clockwise phase progression are found at larger elevation angles in the sky as the result of a birefringent subionospheric wave propagation attributed to ordinary and extraordinary waves. These results imply that long range lightning detection networks might benefit from an exploration of the wave propagation conditions with mini arrays.

MiniWall Tool for Analyzing CFD and Wind Tunnel Large Data Sets

NASA Technical Reports Server (NTRS)

Schuh, Michael J.; Melton, John E.; Stremel, Paul M.

2017-01-01

It is challenging to review and assimilate large data sets created by Computational Fluid Dynamics (CFD) simulations and wind tunnel tests. Over the past 10 years, NASA Ames Research Center has developed and refined a software tool dubbed the MiniWall to increase productivity in reviewing and understanding large CFD-generated data sets. Under the recent NASA ERA project, the application of the tool expanded to enable rapid comparison of experimental and computational data. The MiniWall software is browser based so that it runs on any computer or device that can display a web page. It can also be used remotely and securely by using web server software such as the Apache HTTP server. The MiniWall software has recently been rewritten and enhanced to make it even easier for analysts to review large data sets and extract knowledge and understanding from these data sets. This paper describes the MiniWall software and demonstrates how the different features are used to review and assimilate large data sets.

Conducting Slug Tests in Mini-Piezometers.

PubMed

Fritz, Bradley G; Mackley, Rob D; Arntzen, Evan V

2016-03-01

Slug tests performed using mini-piezometers with internal diameters as small as 0.43 cm can provide a cost effective tool for hydraulic characterization. We evaluated the hydraulic properties of the apparatus in a laboratory environment and compared those results with field tests of mini-piezometers installed into locations with varying hydraulic properties. Based on our evaluation, slug tests conducted in mini-piezometers using the fabrication and installation approach described here are effective within formations where the hydraulic conductivity is less than 1 × 10(-3) cm/s. While these constraints limit the potential application of this method, the benefits to this approach are that the installation, measurement, and analysis is cost effective, and the installation can be completed in areas where other (larger diameter) methods might not be possible. Additionally, this methodology could be applied to existing mini-piezometers previously installed for other purposes. Such analysis of existing installations could be beneficial in interpreting previously collected data (e.g., water-quality data or hydraulic head data). © 2015, National Ground Water Association.

Update on the MiniCLEAN dark matter experiment

DOE PAGES

Rielage, K.; Akashi-Ronquest, M.; Bodmer, M.; ...

2015-03-24

The direct search for dark matter is entering a period of increased sensitivity to the hypothetical Weakly Interacting Massive Particle (WIMP). One such technology that is being examined is a scintillation only noble liquid experiment, MiniCLEAN. MiniCLEAN utilizes over 500 kg of liquid cryogen to detect nuclear recoils from WIMP dark matter and serves as a demonstration for a future detector of order 50 to 100 tonnes. The liquid cryogen is interchangeable between argon and neon to study the A² dependence of the potential signal and examine backgrounds. MiniCLEAN utilizes a unique modular design with spherical geometry to maximize themore » light yield using cold photomultiplier tubes in a single-phase detector. Pulse shape discrimination techniques are used to separate nuclear recoil signals from electron recoil backgrounds. MiniCLEAN will be spiked with additional ³⁹Ar to demonstrate the effective reach of the pulse shape discrimination capability. Assembly of the experiment is underway at SNOLAB and an update on the project is given.« less

Four-stranded mini microtubules formed by Prosthecobacter BtubAB show dynamic instability.

PubMed

Deng, Xian; Fink, Gero; Bharat, Tanmay A M; He, Shaoda; Kureisaite-Ciziene, Danguole; Löwe, Jan

2017-07-18

Microtubules, the dynamic, yet stiff hollow tubes built from αβ-tubulin protein heterodimers, are thought to be present only in eukaryotic cells. Here, we report a 3.6-Å helical reconstruction electron cryomicroscopy structure of four-stranded mini microtubules formed by bacterial tubulin-like Prosthecobacter dejongeii BtubAB proteins. Despite their much smaller diameter, mini microtubules share many key structural features with eukaryotic microtubules, such as an M-loop, alternating subunits, and a seam that breaks overall helical symmetry. Using in vitro total internal reflection fluorescence microscopy, we show that bacterial mini microtubules treadmill and display dynamic instability, another hallmark of eukaryotic microtubules. The third protein in the btub gene cluster, BtubC, previously known as "bacterial kinesin light chain," binds along protofilaments every 8 nm, inhibits BtubAB mini microtubule catastrophe, and increases rescue. Our work reveals that some bacteria contain regulated and dynamic cytomotive microtubule systems that were once thought to be only useful in much larger and sophisticated eukaryotic cells.

Trapped magnetic field of a mini-bulk magnet using YBaCuO at 77 K

NASA Astrophysics Data System (ADS)

Fujimoto, Hiroyuki; Kamijo, Hiroki

2001-09-01

Melt-processed rare earth (RE)123 superconductors have a high Jc at 77 K and high magnetic field. Solidification processes for producing (L)RE123 superconductors and pinning centers in the (L)RE123 matrix are effective for obtaining high Jc, leading to high-field application as a superconducting quasi-permanent bulk magnet with the liquid nitrogen refrigeration. One of the promising applications is a superconducting magnet for the magnetically levitated train. We fabricated a mini-superconducting bulk magnet of 200×100 mm2, consisting of 18 bulks, which are a square 33 mm on a side and 10 mm in thickness, and magnetized the mini-magnet by field cooling. The mini-magnet showed the trapped magnetic field of larger than 0.1 T on the surface of the outer vessel of the magnet. The present preliminary study discusses trapped magnetic field properties of the mini-bulk magnet using YBaCuO superconductors at 77 K.

The October 2014 United States Treasury bond flash crash and the contributory effect of mini flash crashes

PubMed Central

Levine, Zachary S.; Floridi, Luciano

2017-01-01

We investigate the causal uncertainty surrounding the flash crash in the U.S. Treasury bond market on October 15, 2014, and the unresolved concern that no clear link has been identified between the start of the flash crash at 9:33 and the opening of the U.S. equity market at 9:30. We consider the contributory effect of mini flash crashes in equity markets, and find that the number of equity mini flash crashes in the three-minute window between market open and the Treasury Flash Crash was 2.6 times larger than the number experienced in any other three-minute window in the prior ten weekdays. We argue that (a) this statistically significant finding suggests that mini flash crashes in equity markets both predicted and contributed to the October 2014 U.S. Treasury Bond Flash Crash, and (b) mini-flash crashes are important phenomena with negative externalities that deserve much greater scholarly attention. PMID:29091931

MiniWall Tool for Analyzing CFD and Wind Tunnel Large Data Sets

NASA Technical Reports Server (NTRS)

Schuh, Michael J.; Melton, John E.; Stremel, Paul M.

2017-01-01

It is challenging to review and assimilate large data sets created by Computational Fluid Dynamics (CFD) simulations and wind tunnel tests. Over the past 10 years, NASA Ames Research Center has developed and refined a software tool dubbed the "MiniWall" to increase productivity in reviewing and understanding large CFD-generated data sets. Under the recent NASA ERA project, the application of the tool expanded to enable rapid comparison of experimental and computational data. The MiniWall software is browser based so that it runs on any computer or device that can display a web page. It can also be used remotely and securely by using web server software such as the Apache HTTP Server. The MiniWall software has recently been rewritten and enhanced to make it even easier for analysts to review large data sets and extract knowledge and understanding from these data sets. This paper describes the MiniWall software and demonstrates how the different features are used to review and assimilate large data sets.

Single rotor turbine engine

DOEpatents

Platts, David A.

2002-01-01

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

Modal testing of a rotating wind turbine

NASA Astrophysics Data System (ADS)

Carne, T. G.; Nord, A. R.

1982-11-01

A testing technique was developed to measure the modes of vibration of a rotating vertical-axis wind turbine. This technique was applied to the Sandia Two-Meter Turbine, where the changes in individual modal frequencies as a function of the rotational speed were tracked from 0 rpm (parked) to 600 rpm. During rotational testing, the structural response was measured using a combination of strain gages and accelerometers, passing the signals through slip rings. Excitation of the turbine structure was provided by a scheme which suddenly released a pretensioned cable, thus plucking the turbine as it was rotating at a set speed. In addition to calculating the real modes of the parked turbine, the modes of the rotating turbine were also determined at several rotational speeds. The modes of the rotating system proved to be complex due to centrifugal and Coriolis effects. The modal data for the parked turbine were used to update a finite-element model. Also, the measured modal parameters for the rotating turbine were compared to the analytical results, thus verifying the analytical procedures used to incorporate the effects of the rotating coordinate system.

Wind farm electrical system

DOEpatents

Erdman, William L.; Lettenmaier, Terry M.

2006-07-04

An approach to wind farm design using variable speed wind turbines with low pulse number electrical output. The output of multiple wind turbines are aggregated to create a high pulse number electrical output at a point of common coupling with a utility grid network. Power quality at each individual wind turbine falls short of utility standards, but the aggregated output at the point of common coupling is within acceptable tolerances for utility power quality. The approach for aggregating low pulse number electrical output from multiple wind turbines relies upon a pad mounted transformer at each wind turbine that performs phase multiplication on the output of each wind turbine. Phase multiplication converts a modified square wave from the wind turbine into a 6 pulse output. Phase shifting of the 6 pulse output from each wind turbine allows the aggregated output of multiple wind turbines to be a 24 pulse approximation of a sine wave. Additional filtering and VAR control is embedded within the wind farm to take advantage of the wind farm's electrical impedence characteristics to further enhance power quality at the point of common coupling.

Computational study of the effects of shroud geometric variation on turbine performance in a 1.5-stage high-loaded turbine

NASA Astrophysics Data System (ADS)

Jia, Wei; Liu, Huoxing

2013-10-01

Generally speaking, main flow path of gas turbine is assumed to be perfect for standard 3D computation. But in real engine, the turbine annulus geometry is not completely smooth for the presence of the shroud and associated cavity near the end wall. Besides, shroud leakage flow is one of the dominant sources of secondary flow in turbomachinery, which not only causes a deterioration of useful work but also a penalty on turbine efficiency. It has been found that neglect shroud leakage flow makes the computed velocity profiles and loss distribution significantly different to those measured. Even so, the influence of shroud leakage flow is seldom taken into consideration during the routine of turbine design due to insufficient understanding of its impact on end wall flows and turbine performance. In order to evaluate the impact of tip shroud geometry on turbine performance, a 3D computational investigation for 1.5-stage turbine with shrouded blades was performed in this paper. The following geometry parameters were varied respectively: Inlet cavity length and exit cavity length