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1

Mechanical cycling in accelerated life - time tests of lead - free soldered joints  

Microsoft Academic Search

Typical accelerated life-time tests of soldered joints are temperature cycling and thermal shock cycling. In last time other, more economical and effective methods are searched. In Warsaw University of Technology was developed the mechanical cycling method and appropriate test stand. The test samples of printed circuits with soldered components are bent with constant radius at all length of the printed

Zdzislaw Drozd; Jaroslaw Drozd; J. Bronowski; M. Szwech

2005-01-01

2

Accelerated life-time testing and resistance degradation of thin-film decoupling capacitors  

SciTech Connect

Resistance degradation in PZT thin-film capacitors has been studied as a function of applied voltage, temperature, and film composition. It is found that the mean-time-to-failure (life-time or t{sub f}) of the capacitors shows a power law dependence on applied voltage of he form t{sub f} {proportional_to} V{sup {minus}n} (n {approximately} 4--5). The capacitor life-time also exhibits a temperature dependence of the form t{sub f} {proportional_to} exp(E{sub a}/kT), with an activation energy of {approximately} 0.8 eV. The steady-state leakage current in these samples appears to be bulk controlled. The voltage, temperature, and polarity dependence of the leakage current collectively suggest a leakage current mechanism most similar to a Frenkel-Poole process. The life-time and leakage current of the Nb-doped PZT films are superior to the undoped PZT films. This result can be explained based on the point-defect chemistry of the PZT system. Finally, the results indicate that the Nb-doped PZT films meet the essential requirements for decoupling capacitor applications.

Al-Shareef, H.; Dimos, D.

1996-09-01

3

Methodology of Accelerated Life-Time Tests For Stirling-Type 'Bae-Co'- Made Cryocoolers Against Displacer-Blockage by Cryo-Pollutant Deposits.  

National Technical Information Service (NTIS)

This report results from a contract tasking R&D Bureau of the Institute for Low Temperature Physics and Engineering as follows: The contractor will investigate techniques for accelerated testing of cryocooler technology. During this phase of the effort th...

V. Getmanits

2000-01-01

4

Accelerated testing of batteries.  

National Technical Information Service (NTIS)

Three methods of evaluating accelerated battery test data are described. Criteria for each method are used to determine the minimum test matrix required for accurate predictions. Other test methods involving high current discharge and real time techniques...

S. C. Levy P. Bro

1992-01-01

5

Accelerated Corrosion Testing.  

National Technical Information Service (NTIS)

Available methods for accelerated testing of corrosion behavior yield results which are not sufficiently accurate or reliable for predicting the service life of aircraft components and materials which degrade or fail due to environmental attack. Research ...

M. Khobaib

1982-01-01

6

Accelerated Testing Technology.  

National Technical Information Service (NTIS)

The report, in two volumes, is devoted to an investigation into the state-of-the-art of methods for reducing the time and expense associated with life testing, particularly as it relates to parts. The areas investigated are divided into accelerated testin...

W. Yurkowsky R. E. Schafer J. M. Finkelstein

1967-01-01

7

Applications of the Poly-K Statistical Test to Life-Time Cancer Bioassay Studies.  

PubMed

The statistical analysis of cancer bioassay data has historically depended on the pathological determination of the experimental animal's cause of death. The poly-k statistical test has provided a method of statistical analysis of animal bioassay data without the need for cause of death information. The test has been shown to have good statistical properties in the typical 2-year cancer bioassay. However, while the poly-k test has been applied to chronic lifetime animal studies, it has not been formally evaluated with respect to the operating characteristics of this statistical test when applied to such studies. Thus, our objective is to assess the performance of the poly-k test for lifetime studies and to make comparisons with other tests. We observed in one recent lifetime study of the gasoline additive MTBE that the application of the poly-k test was not statistically robust. Simulation studies were subsequently conducted for a limited number of scenarios of lifetime cancer bioassays. These simulations showed that the poly-k test is not statistically robust for testing effect of increasing dose in some lifetime cancer studies. PMID:20508734

Gebregziabher, Mulugeta; Hoel, David

2009-09-01

8

Applications of the Poly-K Statistical Test to Life-Time Cancer Bioassay Studies  

PubMed Central

The statistical analysis of cancer bioassay data has historically depended on the pathological determination of the experimental animal's cause of death. The poly-k statistical test has provided a method of statistical analysis of animal bioassay data without the need for cause of death information. The test has been shown to have good statistical properties in the typical 2-year cancer bioassay. However, while the poly-k test has been applied to chronic lifetime animal studies, it has not been formally evaluated with respect to the operating characteristics of this statistical test when applied to such studies. Thus, our objective is to assess the performance of the poly-k test for lifetime studies and to make comparisons with other tests. We observed in one recent lifetime study of the gasoline additive MTBE that the application of the poly-k test was not statistically robust. Simulation studies were subsequently conducted for a limited number of scenarios of lifetime cancer bioassays. These simulations showed that the poly-k test is not statistically robust for testing effect of increasing dose in some lifetime cancer studies.

Gebregziabher, Mulugeta; Hoel, David

2010-01-01

9

New Accelerated Corrosion Test Methods.  

National Technical Information Service (NTIS)

A project which established accelerated corrosion test methods for conventional Al and new AlLi alloys and surface protection schemes is described. New accelerated testing methods will allow the selection of material and protection schemes with increased ...

U. Koch T. Hack

1991-01-01

10

Regional Accelerated Aging Test  

Microsoft Academic Search

Customers' expectations for a consistent long-term high-level product performance have been increasing year after year, and the automotive industry is leading the trend. As an automotive seating component, polyurethane foam has a direct impact to the perceived value of an occupant, thus providing high durability foam became essential to customer satisfaction. Many tests were developed to evaluate the foam durability

Ryoko Yamasaki; James T. McEvoy

2003-01-01

11

Accelerated Testing Validation  

SciTech Connect

The DOE Fuel Cell technical team recommended ASTs were performed on 2 different MEAs (designated P5 and HD6) from Ballard Power Systems. These MEAs were also incorporated into stacks and operated in fuel cell bus modules that were either operated in the field (three P5 buses) in Hamburg, or on an Orange county transit authority drive cycle in the laboratory (HD6 bus module). Qualitative agreement was found in the degradation mechanisms and rates observed in the AST and in the field. The HD6 based MEAs exhibited lower voltage degradation rates (due to catalyst corrosion) and slower membrane degradation rates in the field as reflected by their superior performance in the high potential hold and open-circuit potential AST tests. The quantitative correlation of the degradation rates will have to take into account the various stressors in the field including temperature, relative humidity, start/stops and voltage cycles.

Mukundan, Rangachary; James, Greg; Davey, John; Langlois, David; Torraco, Dennis; Yoon, Wonseok; Weber, Adam Z; Borup, Rodney L.

2011-07-01

12

Accelerated leach test development program  

SciTech Connect

In FY 1989, a draft accelerated leach test for solidified waste was written. Combined test conditions that accelerate leaching were validated through experimental and modeling efforts. A computer program was developed that calculates test results and models leaching mechanisms. This program allows the user to determine if diffusion controls leaching and, if this is the case, to make projections of releases. Leaching mechanisms other than diffusion (diffusion plus source term partitioning and solubility limited leaching) are included in the program is indicators of other processes that may control leaching. Leach test data are presented and modeling results are discussed for laboratory scale waste forms composed of portland cement containing sodium sulfate salt, portland cement containing incinerator ash, and vinyl ester-styrene containing sodium sulfate. 16 refs., 38 figs., 5 tabs.

Fuhrmann, M.; Pietrzak, R.F.; Heiser, J.; Franz, E.M.; Colombo, P.

1990-11-01

13

Advanced Test Accelerator (ATA) injector  

SciTech Connect

The ATA injector, developed from experience gained from the Experimental Test Accelerator (ETA) linac, has recently been completed. The injector consists of ten 0.25 MV cells that are used to develop 2.5 MV across a single diode gap. The 10 kA beam is extracted from a 500 cm/sup 2/ plasma cathode at average rates of up to 5 Hz and burst rates to 1 kHz. Pulsed power from 20 water filled blumleins is divided and introduced symmetrically through four ports on each cell. All major insulators are fabricated from filled epoxy castings. With these improvements, the ATA injector is smaller than the ETA injector; has a faster pulse response; has lower voltage stress on insulators and higher ultimate performance. Injector characterization tests began in October 1982. These tests include beam current, energy, and emittance measurements.

Jackson, C.H.; Bubp, D.G.; Fessenden, T.J.; Hester, R.E.; Neil, V.K.; Paul, A.C.; Prono, D.S.

1983-03-09

14

New accelerated weathering tests including acid rain  

Microsoft Academic Search

Aprocedure for the design of reliable accelerated weathering tests for service life prediction of automotive coatings was\\u000a developed and used in designing an accelerated test based on SAE method J 1960. The influence of exposure conditions was investigated\\u000a in several accelerated tests. Results from these tests and from Florida exposures were used to optimize test conditions. A\\u000a test cycle that

Magnus Palm; Bo Carlsson

2002-01-01

15

Recycler Ring beam life time  

Microsoft Academic Search

We study the Fermilab Recyler Ring beam life time due to various physical processes associated with beam-gas interactions. This includes single Coloumb scattering, electronic excitations, nuclear and multiple scattering processes. We compare the measured life time with those obtained from theoretical estimations. The results indicate additional processes are also contributing to the actual beam life time

Krishnaswamy Gounder; J. Marriner; T. Anderson; B. C. Brown; C. Gattuso; M. Hu; D. Johnson; S. Mishra; S. Pruss; M. Yang

2001-01-01

16

Next linear collider test accelerator injector upgrade  

Microsoft Academic Search

The Next Linear Collider Test Accelerator (NLCTA) being built at SLAC will integrate the new technologies of X-band accelerator structures and RF systems for the next linear collider, demonstrate multibranch beam-loading energy compensation and suppression of higher-order deflecting modes, and measure the dark current generated by RF field emission in the accelerator [NLC Test Accelerator Conceptual Design Report, SLAC Report

A. D. Yeremian; R. H. Miller

1996-01-01

17

DARHT II Scaled Accelerator Tests on the ETA II Accelerator.  

National Technical Information Service (NTIS)

The DARHT II accelerator at LANL is preparing a series of preliminary tests at the reduced voltage of 7.8 MeV. The transport hardware between the end of the accelerator and the final target magnet was shipped to LLNL and installed on ETA II. Using the ETA...

J. T. Weir E. M. Anaya G. J. Caporaso F. W. Chambers

2005-01-01

18

Focusing on accelerated life testing for cylinders  

Microsoft Academic Search

The study of accelerated life test on cylinders for pneumatic industry is covered in this paper. Accelerated life testing is valuable tools to get information quickly on life distribution which is achieved by subjecting the test units to conditions that are more severe than the normal ones. Long lifetime pneumatic cylinders are selected as the test object. Section I covers

Juan Chen; Jungong Ma; Zhanlin Wang; Andreas Wank

2008-01-01

19

Test stands for testing serial XFEL accelerator modules  

NASA Astrophysics Data System (ADS)

The superconducting accelerator module is the key component of the European X-ray Free Electron Laser (XFEL) project to be built at DESY Hamburg. The XFEL linear accelerator will consist of 100 accelerator modules in order to produce pulsed electron beam with the energy of 17.5 GeV. All accelerator modules have to be tested after the assembly and before being installed in the accelerator tunnel. The tests will take place in the Accelerator Module Test Facility (AMTF) being constructed at DESY. Besides test stands for testing superconducting cavities and magnets constituting the accelerator modules, AMTF will come with three test stands for testing the completed accelerator modules. This paper describes layout of the test stands within the AMTF, cryogenic design of the test stand, design issues of principal components and schedule.

Bozhko, Yury; Anashin, Vadim; Belova, Lyudmila; Boeckmann, Torsten Axel; Kholopov, Michail; Konstantinov, Valeriy; Petersen, Bernd; Pivovarov, Sergey; Pyata, Eugeny; Sellmann, Detlef; Wang, Xilong; Zhirnov, Anatoly; Zolotov, Anatoly

2012-06-01

20

NON DESTRUCTIVE TESTING AND EVALUATION OF HETEROGENEOUS SOLIDS USING NON LINEAR ULTRASONICS AND ACOUSTIC EMISSION: TOWARDS THE ASSESSMENT OF THE MATERIAL REMAINING LIFE TIME  

Microsoft Academic Search

Damage is induced in composite plates with integrated ultrasonic transducers using creep and three points bending tests experiments respectively. In situ measurements of the Acoustic Emission (AE) generated by the created damage and the non linear acoustic vibration of the samples are performed. Concerning creep experiment, recorded strain and AE rates exhibit both a power -law acceleration before global failure.

Mourad Bentahar; Hanane Nechad; Anne Marec; Jean-Hugh Thomas

21

Next Linear Collider test accelerator injector upgrade  

Microsoft Academic Search

The Next Linear Collider Test Accelerator (NLCTA) being built at SLAC will integrate the new technologies of X-band Accelerator structures and RF systems for the Next Linear Collider, demonstrate multibunch beam-loading energy compensation and suppression of higher-order deflecting modes, and measure the dark current generated by RF field emission in the accelerator. The current injector being constructed for phase 1

A. D. Yeremian; R. H. Miller

1995-01-01

22

Vacuum system for Advanced Test Accelerator  

Microsoft Academic Search

The Advanced Test Accelerator (ATA) is a pulsed linear electron beam accelerator designed to study charged particle beam propagation. ATA is designed to produce a 10,000 amp 50 MeV, 70 ns electron beam. The electron beam acceleration is accomplished in ferrite loaded cells. Each cell is capable of maintaining a 70 ns 250 kV voltage pulse across a 1 inch

Denhoy

1981-01-01

23

Recycler ring beam life time.  

National Technical Information Service (NTIS)

We study the Fermilab Recycler Ring beam life time due to various physical processes associated with beam-gas interactions. This includes single coulomb scattering, electronic excitations, nuclear and multiple scattering processes. We compare the measured...

K. Gounder

2001-01-01

24

Accelerated life tests at higher usage rates  

Microsoft Academic Search

Accelerated life tests are extensively used to provide quickly the information about the life distributions of products. Test units are subjected to elevated stresses which yield shorter lives. For some products whose life is defined by usage, e.g., mileage and cycles, test units are also run at higher usage rates (UR) to compress the test time. This paper presents a

Guangbin Yang

2005-01-01

25

Accelerated heat exchanger core testing  

Microsoft Academic Search

A program has been started at Argonne National Laboratory to test high performance evaporators and condensers being considered for the 1-MWe ocean test of OTEC heat exchangers. The experimental part of the program will be carried out in a test facility containing three loops - warm water, cold water, and ammonia. The test units will be about 1\\/40th the size

N. F. Sather

1977-01-01

26

Solid oxide materials research accelerated electrochemical testing  

SciTech Connect

The objectives of this work were to develop methods for accelerated testing of cathode material for solid oxide fuel cells under selected operating conditions. The methods would be used to evaluate the performance of LSM cathode material.

Armstrong, T.R.; Windisch, C.; Arey, B.

1995-12-31

27

Copper plating the ground test accelerator RFQ.  

National Technical Information Service (NTIS)

The copper-plating process for the Ground Test Accelerator (GTA) radio frequency quadrupole (RFQ) vanes required a full development program and tight quality control procedures. The copper plating development program utilized full-size RFQ major and minor...

H. Mignardot J. Uher

1991-01-01

28

A bibliography of accelerated test plans  

Microsoft Academic Search

This article provides a current bibliography of 159 references on statistical plans for accelerated tests. It will aid practitioners in selecting plans, and will stimulate researchers to develop needed plans & software.

W. B. Nelson

2005-01-01

29

Particle accelerators test cosmological theory  

SciTech Connect

Over the past decade two subfields of science, cosmology and elementary-particle physics, have become married in a symbiotic relationship that has produced a number of exciting offspring. These offspring are beginning to yield insights on the creation of spacetime and matter at epochs as early as 10 to the minus 43 to 10 to the minus 35 second after the birth of the universe in the primordial explosion known as the big bang. Important clues to the nature of the big bang itself may even come from a theory currently under development, known as the ultimate theory of everything (T.E.O.). A T.E.O. would describe all the interactions among the fundamental particles in a single bold stroke. Now that cosmology ahs begun to make predictions about elementary-particle physics, it has become conceivable that those cosmological predictions could be checked with carefully controlled accelerator experiments. It has taken more than 10 years for accelerators to reach the point where they can do the appropriate experiments, but the experiments are now in fact in progress. The preliminary results confirm the predictions of cosmology. The cosmological prediction the authors have been concerned with pertains to setting limits on the number of fundamental particles of matter. It appears that there are 12 fundamental particles, as well as their corresponding antiparticles. Six of the fundamental particles are quarks. The other six are leptons. The 12 particles are grouped in three families, each family consisting of four members. Cosmology suggests there must be a finite number of families and, further limits the possible range of to small values: only three or at most four families exist. 7 figs.

Schramm, D.N.; Steigman, G.

1988-06-01

30

46 CFR 160.072-5 - Accelerated weathering test.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Accelerated weathering test. 160.072-5 Section 160...Flag § 160.072-5 Accelerated weathering test. (a) Condition the flag...d) The flag fails the accelerated weathering test if (1) After...

2009-10-01

31

46 CFR 160.072-5 - Accelerated weathering test.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Accelerated weathering test. 160.072-5 Section 160...Flag § 160.072-5 Accelerated weathering test. (a) Condition the flag...d) The flag fails the accelerated weathering test if (1) After...

2010-10-01

32

Ultra Accelerated Testing of PV Module Components  

SciTech Connect

Using concentrated natural sunlight at the NREL High Flux Solar Furnace, we have exposed several materials to acceleration factors of up to 400 times the normal outdoor UV exposure dose. This accelerated rate allows the exposure of materials such that a year of outdoor exposure can be simulated in about 5 hours. We have studied the solarization of cerium containing glass, the degradation of ethylene vinyl acetate laminated between borosilicate glass, and the yellowing of standard polystyrene test coupons. The first two candidates are of interest to the photovoltaics (PV) program, and the last candidate material is a widely used dosimeter for ultra violet (UV) exposure in accelerated weathering chambers

Pitts, J. R.; King, D. E.; Bingham, C.; Czanderna, A. W.

1998-10-28

33

Focusing on accelerated life testing for cylinders  

NASA Astrophysics Data System (ADS)

The study of accelerated life test on cylinders for pneumatic industry is covered in this paper. Accelerated life testing is valuable tools to get information quickly on life distribution which is achieved by subjecting the test units to conditions that are more severe than the normal ones. Long lifetime pneumatic cylinders are selected as the test object. Section I covers the fault mechanism analysis, the piston and piston pole parking are the weak units as they are movable parts as well as leakage sources which easily result in the cylinders failure. Liquid temperature and operating frequency are chosen as stresses since their accelerating potentials are available for the specific cylinders. The complete ALT data is presented using Weibull distribution. Estimation for the parameters of failure model and other characteristics of cylinders population life distribution are done successfully. From the 3-axis graph plotted, the effects of each stresses to cylinders can be seen clearly which provide useful results for cylinders researcher and developer.

Chen, Juan; Ma, Jungong; Wang, Zhanlin; Wank, Andreas

2008-11-01

34

The accelerated testing of cements in brines  

SciTech Connect

Cementitious materials may be employed in settings where they face prolonged exposure to Mg-rich brines. This study evaluated the possibility of using high temperatures to accelerate brine-cement reaction rates. Class-H cement coupons were tested in Mg-K-Na-C1- SO{sub 4} brines to 100{degrees}C. MgC1{sub 2}-NaC1 solutions were also employed in a test sequence that extended to 200{degrees}C. It was found that accelerated testing could be used successfully to evaluate the compatability of cementitious materials with such brines.

Krumhansl, J.L.

1993-12-31

35

Accelerated Reliability Testing Utilizing Design of Experiments.  

National Technical Information Service (NTIS)

This report documents a system-level Accelerated Reliability testing methodology. The method requires no specific assumptions of a Time-to-Failure distribution nor a stress/performance model. The methodology results in a multi-stress environmental test ba...

B. T. McKinney

1993-01-01

36

Accelerated testing for failures of tantalum capacitors  

Microsoft Academic Search

This study focused on the use of accelerated testing to find out why tantalum capacitors fail. Stress effects of humidity, temperature, and ripple voltage were examined in different combinations. Results show that a standard 85\\/85 test with combined enhanced moisture and temperature does not result in failure of tantalum capacitors in 2500h. However, with added ripple voltage, failures may occur

J. Virkki; T. Seppl; L. Frisk; P. Heino

2010-01-01

37

Accelerated Corrosion Test for Metal Drainage Pipes.  

National Technical Information Service (NTIS)

The study represents an attempt to develop an accelerated test which would assist the highway engineer in evaluating the usefulness of a new type of coated steel culvert. The test method was to be short in duration (in the order of days), and the results ...

J. D. Garber J. H. Lin

1987-01-01

38

Accelerated degradation testing of a photovoltaic module  

NASA Astrophysics Data System (ADS)

There are a great many photovoltaic (PV) modules installed around the world. Despite this, not enough is known about the reliability of these modules. Their electrical power output decreases with time mainly as a result of the effects of corrosion, encapsulation discoloration, and solder bond failure. The failure of a PV module is defined as the point where the electrical power degradation reaches a given threshold value. Accelerated life tests (ALTs) are commonly used to assess the reliability of a PV module. However, ALTs provide limited data on the failure of a module and these tests are expensive to carry out. One possible solution is to conduct accelerated degradation tests. The Wiener process in conjunction with the accelerated failure time model makes it possible to carry out numerous simulations and thus to determine the failure time distribution based on the aforementioned threshold value. By this means, the failure time distribution and the lifetime (mean and uncertainty) can be evaluated.

Charki, Abdrafi; Laronde, Rmi; Bigaud, David

2013-01-01

39

Next linear collider test accelerator injector upgrade  

SciTech Connect

The Next Linear Collider Test Accelerator (NLCTA) being built at SLAC will integrate the new technologies of X-band Accelerator structures and RF systems for the Next Linear Collider, demonstrate multibunch beam-loading energy compensation and suppression of higher-order deflecting modes, and measure the dark current generated by RF field emission in the accelerator. The current injector being constructed for phase 1 of the NLCTA tests is a simple injector consisting of a gun with a 150 ns long pulse and X-band bunching and accelerating system. While the injector will provide average currents comparable to what is needed for NLC it will not provide the bunch structure since every X-band RF bucket will be filled. The injector upgrade will produce a similar bunch train as planned for NLC mainly a train of bunches 1.4 ns apart with 3 nC in each bunch up to 50 to 60 MeV. The bunching system for the upgrade is more elaborate than the current injector and the plan is to produce a bunch train right at the gun. The difference between the NLCTA injector upgrade and the planned injector for NLC is that the NLCTA injector will not have polarized beam and the accelerator sections are X-band rather than S-band. If the authors are able to produce beams comparable to the NLC requirements with the X-band injector then it should be easier to do with the S-band.

Yeremian, A.D.; Miller, R.H.

1995-08-01

40

Test Stand for Linear Induction Accelerator Optimization  

SciTech Connect

Lawrence Livermore National Laboratory has designed and constructed a test stand to improve the voltage regulation in our Flash X-Ray (FXR) accelerator cell. The goal is to create a more mono-energetic electron beam that will create an x-ray source with a smaller spot size. Studying the interaction of the beam and pulse-power system with the accelerator cell will improve the design of high-current accelerators at Livermore and elsewhere. On the test stand, a standard FXR cell is driven by a flexible pulse-power system and the beam current is simulated with a switched center conductor. The test stand is fully instrumented with high-speed digitizers to document the effect of impedance mismatches when the cell is operated under various full-voltage conditions. A time-domain reflectometry technique was also developed to characterize the beam and cell interactions by measuring the impedance of the accelerator and pulse-power component. Computer models are being developed in parallel with the testing program to validate the measurements and evaluate different design changes. Both 3D transient electromagnetic and circuit models are being used.

Ong, M; DeHope, B; Griffin, K; Goerz, D; Kihara, R; Vogtlin, G; Zentler, J M; Scarpetti, R

2003-06-03

41

Establishment of accelerated corrosion testing conditions  

Microsoft Academic Search

The development of the theoretical and experimental basis of accelerated atmospheric corrosion testing (ACT) of metals, whole machines and\\/or their components are discussed in this paper. It is apparent that current techniques for ACT should be improved. One approach, to establish the necessary environmental conditions for ACT on various products, is determine the range of metallic corrosion based upon the

Lev M. Klyatis

2002-01-01

42

Ultra accelerated testing of PV module components  

SciTech Connect

Using concentrated natural sunlight at the NREL High Flux Solar Furnace, we have exposed several materials to acceleration factors of up to 400 times the normal outdoor UV exposure dose. This accelerated rate allows the exposure of materials such that a year of outdoor exposure can be simulated in about 5 hours. We have studied the solarization of cerium containing glass, the degradation of ethylene vinyl acetate laminated between borosilicate glass, and the yellowing of standard polystyrene test coupons. The first two candidates are of interest to the photovoltaics (PV) program, and the last candidate material is a widely used dosimeter for ultra violet (UV) exposure in accelerated weathering chambers. {copyright} {ital 1999 American Institute of Physics.}

Pitts, J.R.; King, D.E.; Bingham, C.; Czanderna, A.W. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, Colorado 80401 (United States)

1999-03-01

43

Vacuum system for Advanced Test Accelerator  

SciTech Connect

The Advanced Test Accelerator (ATA) is a pulsed linear electron beam accelerator designed to study charged particle beam propagation. ATA is designed to produce a 10,000 amp 50 MeV, 70 ns electron beam. The electron beam acceleration is accomplished in ferrite loaded cells. Each cell is capable of maintaining a 70 ns 250 kV voltage pulse across a 1 inch gap. The electron beam is contained in a 5 inch diameter, 300 foot long tube. Cryopumps turbomolecular pumps, and mechanical pumps are used to maintain a base pressure of 2 x 10/sup -6/ torr in the beam tube. The accelerator will be installed in an underground tunnel. Due to the radiation environment in the tunnel, the controlling and monitoring of the vacuum equipment, pressures and temperatures will be done from the control room through a computer interface. This paper describes the vacuum system design, the type of vacuum pumps specified, the reasons behind the selection of the pumps and the techniques used for computer interfacing.

Denhoy, B.S.

1981-09-03

44

Ultra-accelerated natural sunlight exposure testing  

SciTech Connect

Process and apparatus are disclosed for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: (a) concentrating solar flux uniformly; (b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

Jorgensen, G.J.; Bingham, C.; Goggin, R.; Lewandowski, A.A.; Netter, J.C.

2000-06-13

45

An Accelerated Method for Soldering Testing  

SciTech Connect

An accelerated method for testing die soldering has been developed. High intensity ultrasonic vibrations have been applied to simulate the die casting conditions such as high pressure and high molten metal velocity on the pin. The soldering tendency of steels and coated pins has been examined. The results suggest that in the low carbon steel/Al system, the onset of soldering is 60 times faster with ultrasonic vibration than that without ultrasonic vibration. In the H13/A380 system, the onset of soldering reaction is accelerated to between 30-60 times. Coatings significantly reduce the soldering tendency. For purposes of this study, several commercial coatings from Balzers demonstrated the potential for increasing the service life of core pins between 15 and 180 times.

Han, Qingyou [ORNL; Xu, Hanbing [University of Tennessee, Knoxville (UTK); Ried, Paul [Ried, Engineering; Olson, Paul [Balzers, Inc.

2007-01-01

46

Commissioning of the Ground Test Accelerator RFQ  

SciTech Connect

The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H{sup {minus}} beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on-line. The commissioning stages are the 35 key H{sup {minus}} injector, the 2.5 MeV Radio Frequency Quadrupole (RFQ), the Intertank Matching Section (IMS), the 3.2 MeV first 2{beta}{gamma} Drift Tube Linac (DTL-1) module, the 8.7 MeV 2{beta}{gamma} DTL (modules 1--5), and the 24 MeV GTA; all 10 DTL modules. Commissioning results from the RFQ beam experiments will be presented along with comparisons to simulations.

Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Brown, S.; Connolly, R.; Garnett, R.; Gilpatrick, J.D.; Guy, F.W.; Ingalls, W.B.; Little, C.; Lohson, R.A.; Lloyd, S.; Neuschaefer, G.; Power, J.; Saadatmand, K.; Sandoval, D.P.; Stevens, R.R.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

1992-09-01

47

Commissioning of the Ground Test Accelerator RFQ  

SciTech Connect

The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H{sup {minus}} beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on-line. The commissioning stages are the 35 key H{sup {minus}} injector, the 2.5 MeV Radio Frequency Quadrupole (RFQ), the Intertank Matching Section (IMS), the 3.2 MeV first 2{beta}{gamma} Drift Tube Linac (DTL-1) module, the 8.7 MeV 2{beta}{gamma} DTL (modules 1--5), and the 24 MeV GTA; all 10 DTL modules. Commissioning results from the RFQ beam experiments will be presented along with comparisons to simulations.

Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Brown, S.; Connolly, R.; Garnett, R.; Gilpatrick, J.D.; Guy, F.W.; Ingalls, W.B.; Little, C.; Lohson, R.A.; Lloyd, S.; Neuschaefer, G.; Power, J.; Saadatmand, K.; Sandoval, D.P.; Stevens, R.R.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

1992-01-01

48

Accelerated Leach Test(s) Program: Annual report  

SciTech Connect

A computerized data base of LLW leaching data has been developed. Long-term tests on portland cement, bitumen and vinyl ester-styrene (VES) polymer waste forms containing simulated wastes are underway which are designed to identify and evaluate factors that accelerate leaching without changing the mechanisms.

Dougherty, D.R.; Pietrzak, R.F.; Fuhrmann, M.; Colombo, P.

1986-09-01

49

Accelerated Testing of Coatings for Protection against Atmospheric Corrosion.  

National Technical Information Service (NTIS)

The intention of this project has been to increase the validity of results obtained during accelerated testing of paint films. The often observed lack of correlation between results of accelerated artificial corrosion tests of corrosion protective paint f...

U. Steinsmo

1994-01-01

50

The Brookhaven accelerator test facility injection system  

SciTech Connect

The Brookhaven Accelerator Test Facility (ATF) consists of a 50-MeV/c electron linac and a high-brightness RF-gun both operating at 2856 MHz. An extremely short (a few picoseconds) electron pulse with low transverse emittance is generated by the RF-gun. In order to preserve both longitudinal and transverse emittances, great care must be taken in transporting the electron beam from the RF-gun to the linac. We describe the injection line, present first- and second-order lattice studies of the injection line, and study nonlinear effects on the emittance. 11 refs., 4 figs., 4 tabs.

Wang, X.J.; Kirk, H.G.; Pellegrini, C.; McDonald, K.T.; Russell, D.P.

1989-01-01

51

Design of full-scale highway accelerated loading testing  

Microsoft Academic Search

The full-scale highway accelerated loading testing facility is an international fashionable and popular equipment of evaluting a commendatory reasonable pavement structure's performance, so a highway accelerated loading testing facility is developed, which has self-owned intellectual property. The mechanical structure and the control system of the highway accelerated loading testing based on CAN bus is studied, whose software and the hardware

Zhiguang Guan; Xuguang Wang; Jiwei Zhang; Mingxing Lin

2009-01-01

52

Induction accelerator test module for HIF  

SciTech Connect

An induction linac test module suitable for investigating the drive requirements and the longitudinal coupling impedance of a high-power ion induction linac has been constructed by the Heavy Ion Fusion (HIF) group at LBL. The induction linac heavy ion driver for inertial confinement fusion (ICF) as presently envisioned uses multiple parallel beams which are transported in separate focusing channels but accelerated together in the induction modules. The resulting induction modules consequently have large beam apertures-1--2 meters in diameter- and correspondingly large outside diameters. The module geometry is related to a low-frequency gap capacity'' and high-frequency structural resonances, which are affected by the magnetic core loading and the module pulser impedance. A description of the test module and preliminary results are presented. 3 figs.

Faltens, A.

1991-04-01

53

Using Accelerated Testing to Predict Module Reliability  

SciTech Connect

Long-term reliability is critical to the cost effectiveness and commercial success of photovoltaic (PV) products. Today most PV modules are warranted for 25 years, but there is no accepted test protocol to validate a 25-year lifetime. The qualification tests do an excellent job of identifying design, materials, and process flaws that are likely to lead to premature failure (infant mortality), but they are not designed to test for wear-out mechanisms that limit lifetime. This paper presents a method for evaluating the ability of a new PV module technology to survive long-term exposure to specific stresses. The authors propose the use of baseline technologies with proven long-term field performance as controls in the accelerated stress tests. The performance of new-technology modules can then be evaluated versus that of proven-technology modules. If the new-technology demonstrates equivalent or superior performance to the proven one, there is a high likelihood that they will survive versus the tested stress in the real world.

Wohlgemuth, J. H.; Kurtz, S.

2011-01-01

54

Accelerated Testing Technology. Volume II. Handbook of Accelerated Life Testing Methods.  

National Technical Information Service (NTIS)

The report, in two volumes, is devoted to an investigation into the state-of-the-art of methods for reducing the time and expense associated with life testing, particularly as it relates to parts. The areas investigated are divided into accelerated testin...

J. M. Finkelstein R. E. Schafer W. Yurkowsky

1967-01-01

55

Testing Planck-Scale Gravity with Accelerators  

NASA Astrophysics Data System (ADS)

Quantum or torsion gravity models predict unusual properties of space-time at very short distances. In particular, near the Planck length, around 10-35m, empty space may behave as a crystal, singly or doubly refractive. However, this hypothesis remains uncheckable for any direct measurement, since the smallest distance accessible in experiment is about 10-19m at the LHC. Here I propose a laboratory test to measure the space refractivity and birefringence induced by gravity. A sensitivity from 10-31m down to the Planck length could be reached at existent GeV and future TeV energy lepton accelerators using laser Compton scattering. There are already experimental hints for gravity signature at distances approaching the Planck length by 5-7 orders of magnitude, derived from SLC and HERA data.

Gharibyan, Vahagn

2012-10-01

56

Testing Planck-scale gravity with accelerators.  

PubMed

Quantum or torsion gravity models predict unusual properties of space-time at very short distances. In particular, near the Planck length, around 10(-35)??m, empty space may behave as a crystal, singly or doubly refractive. However, this hypothesis remains uncheckable for any direct measurement, since the smallest distance accessible in experiment is about 10(-19)??m at the LHC. Here I propose a laboratory test to measure the space refractivity and birefringence induced by gravity. A sensitivity from 10(-31)??m down to the Planck length could be reached at existent GeV and future TeV energy lepton accelerators using laser Compton scattering. There are already experimental hints for gravity signature at distances approaching the Planck length by 5-7 orders of magnitude, derived from SLC and HERA data. PMID:23083234

Gharibyan, Vahagn

2012-10-04

57

Fault mechanism analysis and accelerate life testing for pneumatic cylinders  

Microsoft Academic Search

This paper focuses on accelerated life test on cylinders for pneumatic industry which sharply shortens the test time to get the reliability evaluation specification and decreases the cost during products development stage. Accelerated tests are valuable tools to get information quickly on life distribution which is achieved by subjecting the test units to conditions that are more severe than the

Chen Juan; Ma Jungong; Wu Qiang

2008-01-01

58

A fundamental overview of accelerated-testing analytic models  

Microsoft Academic Search

Accelerated testing is often promoted as a solution to saving test time and costs. However, if ignorance about the true significance of accelerated test models prevails, then these tests could result in penalties to cost-effective product development efforts rather than the hoped-for reductions. Using physics of failure models, this paper emphasizes that: there are no magic analytical models that simply,

Hank Caruso; A. Dasgupta

1998-01-01

59

Operation of the Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program.

Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

1992-10-01

60

Operation of the Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program.

Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

1992-01-01

61

Next linear collider test accelerator injector design and status  

SciTech Connect

The Next Linear Collider Test Accelerator (NLCTA) being built at SLAC will integrate the new technologies of X-band accelerator structures and RF systems for the Next Linear Collider, demonstrate multibunch beam-loading energy compensation and suppression of higher-order deflecting modes, measure transverse components of the accelerating field, and measure the dark current generated by RF field emission in the accelerator Injector design and simulation results for the NLCTA injector are discussed.

Yeremian, A.D.; Miller, R.H.; Wang, J.W.

1994-08-01

62

Advanced Accelerator Test Facility (AATF) upgrade plan  

SciTech Connect

We have successfully demonstrated the principles of wake-field acceleration using structures (cavity, dielectric) and plasmas as wake-field devices using the AATF at Argonne National Laboratory. Due to the limited driver electron pulse intensity and relative long pulse length, only modest accelerating gradients were observed. In order to study the wake field effects in much greater detail and demonstrate the feasibility of wake-field accelerator for high energy physics, we are considering construction of a laser photocathode injector on the existing 20 MeV Chem-Linac to produce very intense and short electron pulses. 10 refs., 5 figs.

Gai, W.; Ho, C.; Konecny, R.; Mtingwa, S.; Norem, J.; Rosenzweig, J.; Schoessow, P.; Simpson, J.; Cole, B.; Rosing, M.

1989-01-01

63

Ground test accelerator control system software  

Microsoft Academic Search

The GTA control system provides an environment in which the automation of a state-of-the-art accelerator can be developed. It makes use of commercially available computers, workstations, computer networks, industrial I\\/O equipment, and software. This system has built-in supervisory control (like most accelerator control systems), tools to support continuous control (like the process control industry), and sequential control for automatic startup

L. Burczyk; R. Dalesio; R. Dingler; J. Hill; J. A. Howell; D. Kerstiens; R. King; A. Kozubal; C. Little; V. Martz; R. Rothrock; J. Sutton

1988-01-01

64

Multiple Stress Effect Analysis on Pneumatic Cylinders Accelerated Life Testing  

Microsoft Academic Search

Accelerated life testing is a valuable tool to get information quickly on lifetime distribution which is achieved by subjecting the test units to conditions that are more severe than the normal ones. This paper firstly describes a model for multiple stress-type accelerated life data which is based on the widely known log-linear model and is formulated with Weibull model for

Chen Juan; Wang Deyi; Wu Qiang; Wang Zhanlin

2009-01-01

65

Development of an Accelerated Corrosion Test for Screening Antifreeze Compounds.  

National Technical Information Service (NTIS)

The objective of this study was to develop an accelerated laboratory corrosion test for screening all antifreeze compounds, eliminating the need to conduct the costly and time-consuming simulated service test. The results of this phase of research indicat...

J. H. Conley R. G. Jamison

1982-01-01

66

Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing.  

National Technical Information Service (NTIS)

Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating sa...

E. L. Montgomery J. C. Curran L. M. Calle M. R. Kolody

2011-01-01

67

Terrestrial Photovoltaic Module Accelerated Test-To-Failure Protocol  

SciTech Connect

This technical report documents a test-to-failure protocol that may be used to obtain quantitative information about the reliability of photovoltaic modules using accelerated testing in environmental temperature-humidity chambers.

Osterwald, C. R.

2008-03-01

68

Ground test accelerator control system software  

SciTech Connect

The GTA control system provides an environment in which the automation of a state-of-the-art accelerator can be developed. It makes use of commercially available computers, workstations, computer networks, industrial I/O equipment, and software. This system has built-in supervisory control (like most accelerator control systems), tools to support continuous control (like the process control industry), and sequential control for automatic startup and fault recovery (like few other accelerator control systems). Several software tools support these levels of control: a real-time operating system (VxWorks) with a real-time kernel (VRTX), a configuration database, a sequencer, and a graphics editor. VxWorks supports multitasking, fast context-switching, and preemptive scheduling. VxWorks/VRTX is a network-based development environment specifically designed to work in partnership with the UNIX operating system. A database provides the interface to the accelerator components. It consists of a run time library and a database configuration and editing tool. A sequencer initiates and controls the operation of all sequence programs (expressed as state programs). A graphics editor gives the user the ability to create color graphic displays showing the state of the machine in either text or graphics form. 11 refs., 2 figs.

Burczyk, L.; Dalesio, R.; Dingler, R.; Hill, J.; Howell, J.A.; Kerstiens, D.; King, R.; Kozubal, A.; Little, C.; Martz, V.; Rothrock, R.; Sutton, J.

1988-01-01

69

A REVIEW OF METHODS FOR DEVELOPING ACCELERATED TESTING CRITERIA  

Microsoft Academic Search

Accelerated vibration testing seeks to compress long service exposures to vibration into a reduced length laboratory test by increasing the amplitude and\\/or frequency of the applied inputs during the laboratory test relative to the amplitude and\\/or frequency experienced during service. This testing procedure provides an important tool that can reduce testing time associated with a new design and reduce time

Charles R. Farrar; Thomas A. Duffey; Phillip J. Cornwell; Matthew T. Bement

70

Testing general relativity with laser accelerated electron beams  

SciTech Connect

Electron accelerations of the order of 10{sup 21} g obtained by laser fields open up the possibility of experimentally testing one of the cornerstones of general relativity, the weak equivalence principle, which states that the local effects of a gravitational field are indistinguishable from those sensed by a properly accelerated observer in flat space-time. We illustrate how this can be done by solving the Einstein equations in vacuum and integrating the geodesic equations of motion for a uniformly accelerated particle.

Gergely, L. A.; Harko, T. [Department of Theoretical Physics, University of Szeged, Szeged 6720, Tisza L. krt. 84, Hungary and Department of Experimental Physics, University of Szeged, 6720 Szeged, Dom ter 9 (Hungary); Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong)

2012-07-09

71

Highly Accelerated Temperature and Humidity Stress Test Technique (HAST)  

Microsoft Academic Search

A method for highly accelerated bias-temperature humidity stress testing is described. This method allows testing in the regime 100C\\/175C and 50% R.H.\\/85% R.H. Experimental results which demonstrate invariance of corrosion failure modes and lognormal sigmas under different high temperature-humidity conditions are presented. Acceleration factors relative to 85C\\/81% R.H. and 60C\\/81% R.H. stress tests are given.

Jeffrey E. Gunn; Sushil K. Malik; Purabi M. Mazumdar

1981-01-01

72

Miniature penetrator (MinPen) acceleration recorder development test  

SciTech Connect

The Telemetry Technology Development Department at Sandia National Laboratories actively develops and tests acceleration recorders for penetrating weapons. This new acceleration recorder (MinPen) utilizes a microprocessor-based architecture for operational flexibility while maintaining electronics and packaging techniques developed over years of penetrator testing. MinPen has been demonstrated to function in shock environments up to 20,000 Gs. The MinPen instrumentation development has resulted in a rugged, versatile, miniature acceleration recorder and is a valuable tool for penetrator testing in a wide range of applications.

Franco, R.J.; Platzbecker, M.R.

1998-08-01

73

Accelerated aging corrosion tests for buried metal structures  

Microsoft Academic Search

It is necessary to identify those measurable soil parameters which dictate the severity of the corrosion problem for coated irons and steels. When this is done, meaningful accelerated aging tests can be designed to validate the reduced corrosion rate for the planned coating. The following discussion introduces the important concepts and measurement parameters in the (a) design of accelerated aging

1996-01-01

74

Outdoor and Accelerated Weathering of Elastomers and Plastics: The Assessment of an Accelerated Weathering Test Chamber.  

National Technical Information Service (NTIS)

A range of elastomers and plastics were exposed in a 'Climatest3 accelerated weathering test chamber which uses a fluorescent source of ultraviolet radiation. The rates of deterioration of the materials exposed in the 'Climatest' were compared with those ...

J. Wright

1972-01-01

75

Harsh solder joint reliability tests by impact drop and highly accelerated life test (HALT)  

Microsoft Academic Search

In this work, board level impact drop test and highly accelerated life test (HALT) were conducted on lead-free soldered assemblies. Harsh solder joint reliability testing are needed for impact drop requirements particularly for portable electronics. Highly accelerated life testing (HALT) is increasingly used for high-end workstation server systems. For drop test, the acceleration and strain were measured for clamped-clamped PCB

F. X. Che; J. H. L. Pang

2004-01-01

76

Electronic accelerator pedal optimal design of intelligent test system  

NASA Astrophysics Data System (ADS)

Developed an intelligent test system for the electronic accelerator pedal, and optimized it. The system uses the three-dimensional motion platform driven by servo motor to realize to control the movement of the electronic accelerator pedal automatically and uses the least squares method to optimize the data for the electronic accelerator pedal which is integrated with linear Hall sensors. Carried on the test experiment to the double electric potential signal output electron accelerator pedal and the results show that the system has excellent dynamic and static performance, and the change of motor parameters and load disturbances has strong robustness. Performance indicators have reached the Euro III emission standard configuration of the electronic accelerator pedal and the new technical requirements.

Li, Quailing; Lin, Min; Guo, Bin; Luo, Zai

2010-12-01

77

Lessons learned on the Ground Test Accelerator control system.  

National Technical Information Service (NTIS)

When we initiated the control system design for the Ground Test Accelerator (GTA), we envisioned a system that would be flexible enough to handle the changing requirements of an experimental project. This control system would use a developers' toolkit to ...

A. J. Kozubal R. E. Weiss

1994-01-01

78

Organization of Accelerated Life Tests on Discrete Transistors.  

National Technical Information Service (NTIS)

General requirements are given for planning a system intended to perform accelerated life tests on discrete transistors in order to evaluate the frequency distribution curve of failures. An examination is made of stresses causing progressive degradation i...

A. Zanini

1974-01-01

79

Accelerated Functional Testing of Digital Microfluidic Biochips  

Microsoft Academic Search

Structural testing of digital microfluidic biochips targets the detection of physical defects, but it does not guarantee robust execution of target bioassays or the integrity of assay outcomes. Functional testing is needed to detect fluidic malfunctions. Such tests ensure, whether or not, the elementary fluidic operations, such as droplet transportation, mixing, incubation, and splitting are reliably executed on the microfluidic

Debasis Mitra; Sarmishtha Ghoshal; Hafizur Rahaman; Bhargab B. Bhattacharya; D. D. Majumder; K. Chakrabarty

2008-01-01

80

Accelerated Functional Testing of Digital Microfluidic Biochips  

Microsoft Academic Search

Structural testing of digital microfluidic biochips targets the detection of physical defects, but it does not guarantee robust execution of target bioassays or the integrity of assay outcomes. Functional testing is needed to detect fluidic malfunctions. Such tests ensure whether or not, the elementary fluidic operations, such as droplet transportation, mixing, incubation, and splitting are reliably executed on the microfluidic

Debasis Mitra; Sarmishtha Ghoshal; Hafizur Rahaman; Bhargab B. Bhattacharya; D. D. Majumder; K. Chakrabarty

2008-01-01

81

TESTING PULSE FORMING NETWORKS WITH DARHT ACCELERATOR CELLS  

SciTech Connect

The Dual Axis Radiographic Hydrotest Facility [DARHT] at Los Alamos will use two induction linacs to produce high-energy electron beams. The electron beams will be used to generate x-rays from bremsstrahlung targets. The x-rays will be used to produce radiographs. The first accelerator is operational now, generating a 60- nanosecond electron beam. The second accelerator is under construction. It will generate a 2-microsecond electron beam. The 78 induction cells of the second axis accelerator will be driven by an equal number of pulse forming networks. Each pulse forming network [PFN] generates a nominal 200-kV, 2-microsecond pulse to drive an accelerator cell. Each pulse forming network consists of a set of four equal-capacitance sub-PFN's, stacked in a Marx configuration. The PFN Test Stand was configured to test newly constructed accelerator cells under conditions of full voltage and pulse duration. The PFN Test Stand also explored jitter, prefire and reliability issues for a pulse forming network operated into a purely resistive load. The PFN Test Stand provided experience operating a simple subsystem of the DARHT accelerator. This subsystem involved controls, diagnostics, data acquisition and archival, power supplies, trigger systems, core reset and a gas flow system for the spark gaps. Issues for the DARHT accelerator were investigated in this small-scale facility.

E.A. ROSE; D.A. DALMAS; J.N. DOWNING; R.D. TEMPLE

2001-06-01

82

Recent progress of the advanced test accelerator  

SciTech Connect

Attempts to further improve the beam brightness from field emission cathodes are currently centered on the issue of how beam optics and phase mixing within the injector transport tend to ''average down'' the beam brightness. Particle simulation work indicates that beam brightness can be significantly improved by simply reducing the injector transport magnetic field and losing peak transport current, i.e., only transporting that high brightness portion of the total current. The simulation results shown in Figure 8 suggest that beam brightness can be increased perhaps a factor of 5 or more simply by ''tuning for brightness'' rather than tuning for peak transported current. If this can indeed be experimentally realized and the resulting beam matched onto accelerator transport (magnetic and/or laser guided) without emittance degradation then simple field emission cathodes would, at least in the immediately near term, saisfy the needs for 10 micron FEL experiments. 8 refs., 8 figs.

Prono, D.S.

1985-05-13

83

Development of a new accelerated salt crystallization test  

Microsoft Academic Search

, a new accelerated salt crystallization test. In this paper the design process leading to the definition of this test is described. Preliminary tests studying the influence of the environmental conditions on the damage development showed that the use of a high, but still realistic, temperature can enhance salt damage. The use of wet-dry cycles was found to be more

Tomas Wijffels; Barbara Lubelli

2006-01-01

84

Numerical Modelling of Thin Pavements Behaviour in Accelerated HVS Tests  

Microsoft Academic Search

Two thin road structures have been tested in accelerated testing by using a Heavy Vehicle Simulator (HVS). Both were surface dressed structures, one with a target 20 cm thick unbound base course layer and the other with the base divided into a 10 cm bitumen stabilized base over 10 cm unbound base. The tested road structures were instrumented to estimate

Sigurdur Erlingsson

2007-01-01

85

Accelerated Test for Filter Media Exposure to Fluoride Environment.  

National Technical Information Service (NTIS)

A simple dip test was devised using 1 wt % HF solution to establish an accelerated test which gives similar information on increase and decrease in tensile strength to that displayed in the exposures in the dynamic test system. Herty Sample Nos. 53, 54, a...

G. S. Petit F. N. Wiggins C. W. Weber

1977-01-01

86

Accelerated test for filter media exposure to fluoride environment  

Microsoft Academic Search

A simple dip test was devised using 1 wt % HF solution to establish an accelerated test which gives similar information on increase and decrease in tensile strength to that displayed in the exposures in the dynamic test system. Herty Sample Nos. 53, 54, and 56 contained only asbestos and L-134 fibers; their unexposed tensile strength ranged from 60 to

G. S. Petit; F. N. Wiggins; C. W. Weber

1977-01-01

87

Residual Life Time at Great Age  

Microsoft Academic Search

The asymptotic behaviour of the residual life time at time $t$ is investigated (for $t \\\\rightarrow \\\\infty$). We derive weak limit laws and their domains of attraction and treat rates of convergence and moment convergence. The presentation exploits the close similarity with extreme value theory.

A. A. Balkema; L. de Haan

1974-01-01

88

ACCELERATED CORROSION TESTING OF GALVANIC COUPLES  

Microsoft Academic Search

New materials and structural designs are required for advanced aircraft functionalities. Long standing standardized corrosion test methods (e.g. ASTM B117) are regularly called out in procurement documents to qualify these new materials. However, it is becoming increasingly evident that these test methods can be misleading resulting in approval of material systems that have very poor in service performance and\\/or the

James F. Dante; Josh Averett; Fritz Friedersdorf; Christy Vestal

89

COMPACT PROTON INJECTOR AND FIRST ACCELERATOR SYSTEM TEST FOR COMPACT PROTON DIELECTRIC WALL CANCER THERAPY ACCELERATOR  

SciTech Connect

A compact proton accelerator for cancer treatment is being developed by using the high-gradient dielectric insulator wall (DWA) technology [1-4]. We are testing all the essential DWA components, including a compact proton source, on the First Article System Test (FAST). The configuration and progress on the injector and FAST will be presented.

Chen, Y; Guethlein, G; Caporaso, G; Sampayan, S; Blackfield, D; Cook, E; Falabella, S; Harris, J; Hawkins, S; Nelson, S; Poole, B; Richardson, R; Watson, J; Weir, J; Pearson, D

2009-04-23

90

Testing of a high current dc ESQ accelerator  

SciTech Connect

A high current dc electrostatic quadrupole (ESQ) accelerator is being developed for negative-ion-based neutral beam heating and current drive on the next generation tokamak. Beam energy and current will eventually be in the MeV and multiampere range.l This CCVV (constant- current variable-voltage) accelerator uses a series of identical ESQ modules. We have successfully tested a prototype CCVV accelerator up to 200 keV with a 100 mA He{sub +} beam (with space charge equivalence of 140 mA of D{sup {minus}}) for a pulse length of 1 s. Testing was also done with a 42 mA H{sup {minus}} beam (H{sup {minus}} beam current was limited by source performance). There was almost no beam loss in the ESQ accelerator. no emittance growth was found in the beam injected from the preaccelerator into the ESQ accelerator had low aberration. We are presently designing a proof-of- principle one-channel CCVV accelerator that would accelerate 1.0 A of D{sup {minus}} 1.3 MeV energy. 4 refs., 7 figs.

Kwan, J.W.; Ackerman, G.D.; Ackerman, O.A.; Chan, C.F.; Cooper, W.S.; deVries, G.J.; Kunkel, W.B.; Soroka, L.; Steele, W.F.; Wells, R.P.

1991-05-01

91

Beam dynamics in the Advanced Test Accelerator (ATA)  

SciTech Connect

We will review the performance of the Advanced Test Accelerator, a 50 MeV, 10 KA induction linac. The discussion will cover the operation of the plasma cathode electron source, beam transport throughout the accelerator, and transverse instabilities. Particular emphasis will be placed on the beam breakup instability and on the methods used to minimize it. These include a program of design changes that lead to an order of magnitude reduction in the Q's of the accelerator cavity modes and optimization of the transport tune.

Caporaso, G.J.; Barletta, W.A.; Birx, D.L.; Briggs, R.J.; Chong, Y.P.; Cole, A.G.; Fessenden, T.J.; Hester, R.E.; Lauer, E.J.; Neil, V.K.

1983-09-28

92

A new facility to test superconducting accelerator magnets  

Microsoft Academic Search

Future high energy accelerators such as the Large Hadron Collider require accelerator magnets with the highest possible fields. For NbTi conductor magnets, this means operating at superfluid helium temperatures in the range of 1.8-1.9 K. As part of Fermilab's superconducting magnet R&D program, we have built a facility to test magnets in a vertical dewar of superfluid liquid helium. The

M. J. Lamm; J. DiMarco; E. Desavouret; S. Feher; J. D. Garvey; C. Hess; P. J. Limon; J. M. Nogiec; D. F. Orris; J. Pachnik; T. Peterson; S. Sharonov; J. B. Strait; C. Sylvester; J. W. Sim; M. Tartaglia; J. C. Tompkins; A. V. Zlobin

1997-01-01

93

A NEW FACILITY TO TEST SUPERCONDUCTING ACCELERATOR MAGNETS  

Microsoft Academic Search

Future high energy accelerators such as the Large Hadron Collider require accelerator magnets with the highest possible fields. For NbTi conductor magnets, this means operating at superfluid helium temperatures in the range of 1.8-1.9K. As part of Fermilab's superconducting magnet R&D program, we have built a facility to test magnets in a vertical dewar of superfluid liquid helium. The dewar

M. J. Lamm; J. DiMarco; E. Desavouret; S. Feher; J. D. Garvey; C. Hess; P. J. Limon; J. M. Nogiec; D. F. Orris; J. Pachnik; T. Peterson; S. Sharonov; J. B. Strait; C. Sylvester; J. W. Sim; M. Tartaglia; J. C. Tompkins; A. V. Zlobin; VERTICAL DEWAR

1998-01-01

94

Safety analysis of an accelerator-driven test facility  

Microsoft Academic Search

One of the milestones in the roadmap of accelerator-driven transmutation of waste (ATW) of the U.S. Department of Energy is the design and construction of an accelerator-driven test facility (ADTF) with a thermal power of 100MW. Analysis of the dynamic behavior of the ADTF has been carried out in the frame of a bilateral collaboration between the Forschungszentrum Karlsruhe and

X. Cheng; J. E. Cahalan; P. J. Finck

2004-01-01

95

Commissioning of the Ground Test Accelerator Intertank Matching Section  

Microsoft Academic Search

The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H⁻ beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on-line. The commissioning stages are the 35 keV H⁻ injector, the 2.5 MeV Radio Frequency Quadrupole (RFQ),

K. F. Johnson; O. R. Sander; W. H. Atkins; G. O. Bolme; R. Cole; R. Connolly; J. D. Gilpatrick; W. B. Ingalls; D. Kersteins; C. Little; R. A. Lohsen; W. P. Lysenko; C. T. Mottershead; J. Power; D. P. Rusthoi; D. P. Sandoval; R. R. Stevens; G. Vaughn; E. A. Wadlinger; R. Weiss; V. Yuan

1992-01-01

96

Correlation between accelerated corrosion tests and atmospheric corrosion tests on steel  

Microsoft Academic Search

Three kinds of steel [soft steel (SPHC), carbon steel (SS400), and weathered steel (A588)] were prepared for accelerated corrosion and atmospheric corrosion tests. The results of atmospheric corrosion tests were similar to those of accelerated corrosion tests. A correlation was developed for prediction of atmospheric corrosion rates of steel using atmospheric corrosion factors (i.e. Cl- deposition fluxes, time of wetness,

Chuen-Chang Lin; Chi-Xiang Wang

2005-01-01

97

Reliability evaluation for the pump assembly using an accelerated test  

Microsoft Academic Search

The pump motor assembly in a washing machine is used to drain the dirty water generated during washing the clothes. This research was aimed to develop an accelerated test as to demonstrate a reliability goal of the assembly within an affordable amount of time and in an economic way. They were evaluated under step stress margin tests first in order

Sang-Jun Park; Sang-Deuk Park; Kwang-Suck Kim; Ji-Hyun Cho

2006-01-01

98

Leaching tests on different mortars using accelerated electrochemical method  

Microsoft Academic Search

In designing radioactive waste repositories, it is necessary to predetermine the degree of concrete performance change due to leaching degradation. Leaching tests were carried out on different mortars using an electrochemical method. With this method, a potential gradient is applied across the specimen, which accelerates the dissolution of cement hydrate from mortar in contact with water. Tests were carried out

Hiroshi Saito; Akira Deguchi

2000-01-01

99

Atmospheric corrosion accelerated test apparatus for oxidation studies of uranium.  

National Technical Information Service (NTIS)

An atmospheric corrosion accelerated test apparatus for oxidation studies of uranium and its alloys is developed. This system is used for corrosion tests under conditions of high temperature moist air (105 deg C, 10%R.H., air) and moist N(sub 2) (70 deg C...

X. Zhang

1990-01-01

100

Lognormal and Weibull accelerated life test plans under distribution misspecification  

Microsoft Academic Search

In this article, we derive expressions for the asymptotic distribution of maximum likelihood estimators of model parameters in accelerated life tests (ALTs) when the model distribution is misspecified. We investigate results for two popular models, namely, the lognormal and Weibull Arrhenius-type ALT models. We propose test plan criteria based on asymptotic bias (ABias) and asymptotic mean squared error (AMSE) to

Francis G. Pascual; Grace Montepiedra

2005-01-01

101

Accelerated Durability Testing of Electrochromic Windows  

SciTech Connect

Prototype electrochromic windows made by several different U.S. companies have been tested in our laboratory for their long-term durability. Samples were subjected to alternate coloring and bleaching voltage cycles while exposed to simulated on 1-sun irradiance in a temperature-controlled environmental chamber with low relative humidity. The samples inside the chamber were tested under a matrix of different conditions. These conditions include: cycling at different temperatures (65 C, 85 C, and 107 C) under the irradiance, cycling versus no-cycling under the same irradiance and temperature, testing with different voltage waveforms and duty cycles with the same irradiance and temperature, cycling under various filtered irradiance intensities, and simple thermal exposure with no irradiance or cycling. The electro-optical characteristics of the samples were measured between 350 and 1,100 nm every 4,000 cycles for up to 20,000 cycles. Photographs of the samples were taken periodically wi th a digital camera to record cosmetic defects, the extent of residual coloration, and overall coloration and bleaching uniformity of the samples. Our results indicate that the most important cause of degradation is the combination of continuous cycling, elevated temperature, and irradiance. The relative importance of these variables, when considered synergistically or separately, depends on the particular device materials and design.

Tracy, C. E.; Zhang, J. G.; Benson, D. K.; Czanderna, A. W.; Deb, S. K.

1998-12-29

102

Precision measurement of the life time of the. pi. °  

Microsoft Academic Search

4 methods are described for determining the ..pi..° life time directly from the electron production rates from assemblies of gold foils, traversed by high energy protons. A preliminary value of (0.77 +- 0.05) x 10⁻¹⁶ sec has been obtained in a short test run, in good agreement with the previous world average. The final experiment aims at a 1 percent

von Dardel

1984-01-01

103

Application of the Argonne Advanced Acceleration Test Facility to development for conventional accelerators  

SciTech Connect

The Argonne Advanced Acceleration Test Facility is designed as a powerful tool to test ideas for very high gradient acceleration schemes based on direct beam excitation of plasmas, metal structures, dielectrics, etc. The characteristic size in these systems is )approximately) 1 cm, corresponding to frequencies )approximately) 10 GHz. The question addressed here is whether the special features of this facility have application as well to the development of components for the more conventional, lower frequency, accelerators now operating or under development. It is suggested that the usefulness of the facility for the development of conventional systems could be enhanced by a provision for longer time delay between driver and witness beam pulses. 9 refs., 2 figs.

MacLachlan, J.A.

1988-04-07

104

The current state of the accelerated concrete prism test  

Microsoft Academic Search

Expansions due to alkalisilica reaction (ASR) in the accelerated concrete prism test (ACPT60C) show a significant reduction at 13weeks compared to 52week testing in the standard concrete prism test (CPT38C). Previous work indicated that increased leaching, higher mass loss and a reduction in the pH were observed when temperature was increased from 38 to 60C. After further investigation the authors

Jason H. Ideker; Bradley L. East; Kevin J. Folliard; Michael D. A. Thomas; Benoit Fournier

2010-01-01

105

Optimum constant-stress accelerated life-test plans  

Microsoft Academic Search

This paper deals with optimal design of four-level constant-stress accelerated life test plans with various censoring times. The optimum plans choose the stress levels, test units allocated to each stress, and censoring times to minimize the asymptotic variance of the MLE of the mean (log) life at design stress and test length. A FORTRAN-77 program was written to calculate the

Guang-Bin Yang; Reader Aids

1994-01-01

106

TESTING METGLAS FOR USE IN DARHT ACCELERATOR CELLS  

SciTech Connect

The Dual Axis Radiographic Hydrotest Facility [DARHT] at Los Alamos will use two induction linacs to produce high-energy electron beams. The electron beams will be used to generate x-rays from bremsstrahlung targets. The x-rays will be used to produce radiographs. The first accelerator is operational now, producing a 60-nanosecond electron beam. The second accelerator is under construction. It will produce a 2-microsecond electron beam. The 78 induction cells of the second axis accelerator require a total Metglas capacity of approximately 40 volt seconds of flux. Four Metglas cores are used in each of the 5-foot diameter accelerator cells. Each Metglas core weighs approximately 3000 pounds. This paper presents the measurement techniques and results of the Metglas tests. Routine automated analysis and archival of the pulse data provided hysteresis curves, energy loss curves and total flux swing in the operating regime. Results of the tests were used to help the manufacturer improve quality control and increase the average flux swing of the cores. Results of the tests were used to match Metglas cores and to assemble accelerator cells with equal volt-second ratings.

E.A. ROSE; D.A. DALMAS; J.N. DOWNING; R.D. TEMPLE

2001-06-01

107

High current electron linacs (advanced test accelerator/experimental test accelerator)  

SciTech Connect

The high current induction accelerator development at the Lawrence Livermore National Laboratory is described. The ATA facility is designed for 10 kA peak currents, 50 nsec pulse lengths and 50 MeV energies. At this time, half of the design current has been accelerated through the entire machine to particle energies of about 45 MeV. Current problem areas and operational experience to date will be discussed. Several key technical areas required development for the ATA machine; this report will survey these developments. The control of transverse beam instabilities required an accelerating cavity design with very low Q. Electron sources capable of 10 kA operation at high rep rates were developed using a plasma sparkboard approach. The pulse power systems on ATA, using the same type of spark gap switches as ETA, have exhibited excellent operational reliability.

Briggs, R.J.

1984-04-30

108

The BNL Accelerator Test Facility and experimental program  

SciTech Connect

The Accelerator Test Facility (ATF) at BNL is a users' facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high power laser pulses synchronized to the electron beam, suitable for studies of new methods of high gradient acceleration and state of the art free electron lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 to 100 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps Nd:YAG laser and a 100 mJ, 10 ps CO{sub 2} laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various acceleration schemes, Free-Electron Laser experiments and a program on the development of high brightness electron beams. The AFT's experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the High power laser will begin operation this year. 28 refs., 4 figs.

Ben-Zvi, I. (Brookhaven National Lab., Upton, NY (United States) State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics)

1991-01-01

109

Reliability estimation of aeronautic component by accelerated tests  

Microsoft Academic Search

This article presents a reliability assessment of aeronautic electronic board using the accelerated test approach. The mission profile used is one defined in FIDES for electronic equipment in aircraft. The reliability function is defined taking into account the different phases of product life (Ground, Taxiing, Flying, Dormant). FIDES describes the environment (thermal and humidity, thermal cycling, mechanical, ) for each

S. Charruau; F. Guerin; J. Hernndez Dominguez; J. Berthon

2006-01-01

110

A New Approach to Inference from Accelerated Life Tests.  

National Technical Information Service (NTIS)

A recent paper has proposed a new approach for making inferences from accelerated life tests. Their approach is significantly different from those that have been considered in the past, and is motivated by what is actually done in practice. A priori infor...

F. Proschan N. D. Singpurwalla

1978-01-01

111

New Approach to Inference from Accelerated Life Tests.  

National Technical Information Service (NTIS)

A new approach has been recently proposed for making inferences from accelerated life tests. Their approach is significantly different from those that have been considered in the past, and is motivated by what is actually done in practice. A priori inform...

F. Proschan N. D. Singpurwalla

1978-01-01

112

ATA (Advanced Test Accelerator) beam transport experiment: Optical data  

Microsoft Academic Search

Optical data showing emittance growth through the Advanced Test Accelerator (ATA) beam pulse have been obtained using a new beam profile diagnostic, Cerenkov radiation emitted from a quartz foil inserted into the path of the electron beam. This diagnostic gave extremely bright optical emissions which allowed productive operation of a streak camera in addition to the gated 2-D image-intensified CCD

Y. P. Chong; P. Lee; F. J. Deadrick; D. G. Hirzel; J. S. Kallman; J. F. Poulter; W. E. Rivera; P. L. Stephan

1988-01-01

113

On the inverse power laws for accelerated random fatigue testing  

Microsoft Academic Search

This paper addresses the usage of inverse power laws in accelerated fatigue testing under wide-band Gaussian random loading. The aim is not at predicting an ab- solute value of fatigue life but assessing the fatigue damage relative accumulation. The widely accepted inverse power scaling laws in fatigue damage assessment is discussed, reviewing the engineering standards and pointing out their inherent

G. Allegri; X. Zhang

2009-01-01

114

Apparatus for conducting accelerated corrosion testing of nickel alloys  

Microsoft Academic Search

This patent describes an improved testing apparatus for determining, on an accelerated basis, the susceptibility of a metal to stress corrosion cracking. It comprises vessel means for providing pressurized steam and for containing a stressed specimen of a metal and an atmosphere formed from the pressurized steam and hydrogen; an inlet core positioned and arranged in fluid communication with the

G. Economy; R. J. Jacko; F. W. Pement; A. W. Klein

1991-01-01

115

Accelerated Corrosion Test for Aluminum-Zinc Alloy Coatings  

Microsoft Academic Search

An electrochemically monitored etching method has been developed to enable accelerated service life testing of aluminum\\/zinc alloy coatings with a dendritic microstructure. The method involved pre-exposure of materials to the etching solution to remove the most active phases from the coatings. This process simulated the early phases of atmospheric corrosion. The method significantly shortened the time required for an atmospheric

T. C. Simpson

1993-01-01

116

Estimation of threshold stress in accelerated life-testing  

Microsoft Academic Search

The author presents a method that uses accelerated life-test data to estimate the mean life at the service stress and the threshold stress below which a failure is unlikely to occur. The relation between stress and mean-life at that stress is assumed to follow an inverse power law that includes a threshold stress. The failure times at a given stress

H. Hirose

1993-01-01

117

Research on the reliability of SLD through accelerated life testing  

Microsoft Academic Search

As an important component, Super Luminescent Diode (SLD) is the most crucial factor that affects life and reliability of Interferotic Fiber Opitc Gyroscope(IFOG). Therefore, research on the reliability of SLD is the base of research on the reliability of IFOG. Research on the reliability of SLD was processed through accelerated life test (ALT). Based on related theoretic analysis, the sensitive

Daihong Chao; Jing Ma; Xiaoyang Li

2009-01-01

118

Methods of accelerated vibration fatigue testing of machines and instruments  

NASA Astrophysics Data System (ADS)

A system approach is used to formulate the problem of reliability testing optimization, and solutions are derived by dynamic programming or by applying the rule of the maximum. The proposed optimization techniques provide a way to determine the optimum schedule for accelerated vibration fatigue tests which employ reduced number of cycles combined with high stress amplitudes and high vibration frequencies. The approach is illustrated for internal combustion engine components.

Bozhko, O. E.; Vlasenko, I. P.; Potichenko, V. A.; Savchenko, V. I.; Lichkatii, E. O.

1980-10-01

119

Optimum simple step-stress accelerated life tests with censoring  

Microsoft Academic Search

The authors present the optimum simple time-step and failure-step stress accelerated life tests for the case where a prespecified censoring time is involved. An exponential life distribution with a mean that is a log-linear function of stress, and a cumulative exposure model are assumed. The authors obtain the optimum test plans to minimize the asymptotic variance of the maximum-likelihood estimator

D. S. Bai; M. S. Kim; S. H. Lee

1989-01-01

120

Accelerated Life Test of High Brightness Light Emitting Diodes  

Microsoft Academic Search

Short-term accelerated life test activity on high brightness light emitting diodes is reported. Two families of 1-W light-emitting diodes (LEDs) from different manufacturers were submitted to distinct stress conditions: high temperature storage without bias and high dc current test. During aging, degradation mechanisms like light output decay and electrical property worsening were detected. In particular, the degradation in light efficiency

Lorenzo Trevisanello; Matteo Meneghini; Giovanna Mura; Massimo Vanzi; Maura Pavesi; Gaudenzio Meneghesso; Enrico Zanoni

2008-01-01

121

An Accelerated Method for Testing Soldering Tendency of Core Pins  

SciTech Connect

An accelerated method for testing die soldering has been developed. High intensity ultrasonic vibrations has been used to simulate the die casting conditions such as high pressure and high impingement speed of molten metal on the pin. Soldering tendency of steels and coated pins has been examined. The results indicate that in the low carbon steel/Al system, the onset of soldering is 60 times faster with ultrasonic vibration than that without ultrasonic vibration. In the H13/A380 system, the onset of soldering reaction is accelerated to 30-60 times. Coating significantly reduces the soldering tendency of the core pins.

Han, Qingyou [ORNL; Xu, Hanbing [ORNL; Ried, Paul [Ried, Engineering; Olson, Paul [Balzers, Inc.

2010-01-01

122

Cryogenic cooling system for the ground test accelerator  

SciTech Connect

A cryogenic cooling system has been designed, built and tested for the Ground Test Accelerator (GTA) at the Los Alamos National Laboratory. Major components of the GTA require cooling to less than 50 K to reduce rf-heating and to increase thermal stability. The cooling system is capable of cooling (at an acceptable rate for thermal stresses) the cryogenically cooled components and then maintaining them at their operating temperature during accelerator testing for all modes and power levels of operation. The accelerator components are cooled by circulating cold, dense helium gas (about 21 K and 2.1 MPa) through the components. The circulating helium is refrigerated in a heat exchanger that uses boiling liquid hydrogen as a source of refrigeration. The cryogenic cooling system consists of the following major components: a liquid hydrogen (LH{sub 2}) storage Dewar with a transfer line to an LH{sub 2} run tank containing an LH{sub 2}/gaseous helium (GHe) heat exchanger, circulation lines, and a circulation pump. The system, sized to cool a load of approximately 40 kW at temperatures as low as 20 K, is operational, but has not yet been operated in conjunction with the accelerator.

Edeskuty, F.J.; Stewart, W.F.; Moeller, J.; Durham, F. [Los Alamos National Lab., NM (United States); Spulgis, I. [CVI, Inc., Columbus, OH (United States)

1993-06-01

123

Cryogenic cooling system for the ground test accelerator  

SciTech Connect

A cryogenic cooling system has been designed, built and tested for the Ground Test Accelerator (GTA) at the Los Alamos National Laboratory. Major components of the GTA require cooling to less than 50 K to reduce rf-heating and to increase thermal stability. The cooling system is capable of cooling (at an acceptable rate for thermal stresses) the cryogenically cooled components and then maintaining them at their operating temperature during accelerator testing for all modes and power levels of operation. The accelerator components are cooled by circulating cold, dense helium gas (about 21 K and 2.1 MPa) through the components. The circulating helium is refrigerated in a heat exchanger that uses boiling liquid hydrogen as a source of refrigeration. The cryogenic cooling system consists of the following major components: a liquid hydrogen (LH[sub 2]) storage Dewar with a transfer line to an LH[sub 2] run tank containing an LH[sub 2]/gaseous helium (GHe) heat exchanger, circulation lines, and a circulation pump. The system, sized to cool a load of approximately 40 kW at temperatures as low as 20 K, is operational, but has not yet been operated in conjunction with the accelerator.

Edeskuty, F.J.; Stewart, W.F.; Moeller, J.; Durham, F. (Los Alamos National Lab., NM (United States)); Spulgis, I. (CVI, Inc., Columbus, OH (United States))

1993-01-01

124

Beam Breakup (BBU) instability experiments on the Experimental Test Accelerator (ETA) and predictions for the Advanced Test Accelerator (ATA)  

SciTech Connect

In linear accelerators the maximum achievable beam current is often limited by the Beam Breakup (BBU) instability. This instability arises from the interaction of a transversely displaced beam with the dipole modes of the acceleration cavities. The modes of interest have non-zero transverse magnetic fields at the center of the cavity. This oscillating field imparts a time varying transverse impulse to the beam as it passes through the accelerating gap. Of the various modes possible only the TM/sub 130/ mode has been observed on the Experimental Test Accelerator (ETA) and it is expected to surface on the Advanced Test Accelerator (ATA). The amplitude of the instability depends sensitively on two cavity parameters; Q and Z/sub perpendicular//Q. Q is the well-known qualtiy factor which characterizes the damping rate of an oscillator. Z/sub perpendicular//Q is a measure of how well the beam couples to the cavity fields of the mode and in turn, how the fields act back on the beam. Lowering the values of both these parameters reduces BBU growth.

Caporaso, G.J.; Cole, A.G.; Struve, K.W.

1983-03-02

125

High-Gradient Photonic Bandgap (PBG) Accelerator Structure Breakdown Testing  

NASA Astrophysics Data System (ADS)

Photonic bandagp (PBG) accelerator structures provide unique insight into the surface physics involved in vacuum breakdown in accelerator structures because of their unique surface E and H fields. Peak operating gradients in accelerator structures are limited by surface breakdowns. These breakdowns occur at regions of high surface E and H fields. The maximum surface H field can easily be varied relative to the peak surface E field and accelerating gradient in PBG structures, allowing new regimes of parameter space to be explored. A standing wave PBG structure utilizing elliptical rods at the highest field locations has been tested at SLAC to determine the breakdown properties of the structure under high-gradient operation. The structure achieved a maximum gradient of approximately 125 MV/m at a breakdown probability of 3.6 *10-3 per pulse per meter for 150 ns pulses. This performance is comparable to conventional disc-loaded waveguide accelerator structures, but in a structure that provides intrinsic damping of wakefields.

Munroe, Brian; Shapiro, Michael; Temkin, Richard; Marsh, Roark; Dolgashev, Valery; Tantawi, Sami; Yeremian, Anahid

2012-10-01

126

Development of an Artificial Climatic Complex Accelerated Corrosion Tester and Investigation of Complex Accelerated Corrosion Test Methods  

Microsoft Academic Search

During recent decades, accelerated corrosion test equipment and methods simulating atmospheric corrosion have been developed to incorporate the many factors involved in complex accelerated corrosion. A new accelerated corrosion tester was developed to simulate various kinds of atmospheric corrosion environments. The equipment can be used to simulate various types of atmospheric corrosion environments with up to eight factors and can

J. Li; M. Li; Z. Sun

1999-01-01

127

Accelerated Service Life Testing of Automotive Vehicles on a Test Course  

Microsoft Academic Search

The accelerated service life testing of automotive vehicles for durability to road roughness induced dynamic loads is often accomplished in the laboratory using road roughness simulation facilities [15]. However, such tests can also be accomplished by a carefully designed field operation on a test course [6], where both the speed of the vehicle and the roughness of die test course

S. Colin ASHMORE; Allan G. PIERSOL; Joseph J. WITTE

1992-01-01

128

On the analysis of accelerated life-testing experiments  

Microsoft Academic Search

One simplification for a particular class of accelerated life-testing experiments is discussed. The efficacy of this simplification is compared with other alternatives. Evidence from simulation experiments shows that the presented simplification is superior. Several measures of precision for maximum-likelihood estimators of model parameters are analyzed. Asymptotically valid results provide a reasonable guide to the precision in these maximum-likelihood estimators

Alan J. Watkins; Reader Aids

1991-01-01

129

Elevated temperature accelerated release testing of PLGA microspheres  

Microsoft Academic Search

Drug release from four different poly(lactic-co-glycolic) acid (PLGA) microsphere formulations was evaluated under real-time (37C) and accelerated release testing conditions of elevated temperature (45, 53, 60 and 70C) and increase in flow rate (435ml\\/min) using United States Pharmacopeia (USP) apparatus 4. Formulation 5K (composed of low Mw PLGA) exhibited diffusion-controlled kinetics in real-time. Whereas, formulations 25K, 28K and 70K (composed

Banu S. Zolnik; Pauline E. Leary; Diane J. Burgess

2006-01-01

130

Test of the law of gravitation at small accelerations  

NASA Astrophysics Data System (ADS)

Newton's Law of Gravitation has been tested at small values a of the acceleration, down to a ? 10-10 ms-2, the approximate value of MOND's constant a 0. Within experimental errors no deviations from Newton's Law were found. A comparison with six versions of the MOND interpolation function is given. Under the assumptions made in this paper one of the versions can be excluded.

Meyer, H.; Lohrmann, E.; Schubert, S.; Bartel, W.; Glazov, A.; Lhr, B.; Niebuhr, C.; Wnsch, E.; Jnsson, L.; Kempf, G.

2012-10-01

131

Accelerated Stability Testing of a Water-in-Oil Emulsion  

Microsoft Academic Search

Non-optimal or non-predictable stability properties of emulsions can be limiting for the applications of emulsions. Therefore, it is of general interest to predict stability behavior. In the present study, accelerated stability testing employing elevated temperatures with good accuracy predicted long-term stability of a w\\/o emulsion stabilized with polyglycerol polyricinoleate (PG PR) kept at 4C. It is argued that elevated temperature

S. Bjerregaard; C. Vermehren; I. Sderberg; S. Frokjaer

2001-01-01

132

Accelerated aging test results for aerospace wire insulation constructions  

NASA Astrophysics Data System (ADS)

Several wire insulation constructions were evaluated with and without continuous glow discharges at low pressure and high temperature to determine the aging characteristics of acceptable wire insulation constructions. It was known at the beginning of the test program that insulation aging takes several years when operated at normal ambient temperature and pressure of 20 C and 760 torr. Likewise, it was known that the accelerated aging process decreases insulation life by approximately 50% for each 10 C temperature rise. Therefore, the first phases of the program, not reported in these test results, were to select wire insulation constructions that could operate at high temperature and low pressure for over 10,000 hours with negligible shrinkage and little materials' deterioration.The final phase of the program was to determine accelerated aging characteristics. When an insulation construction is subjected to partial discharges the insulation is locally heated by the bombardment of the discharges, the insulation is also subjected to ozone and other deteriorating gas particles that may significantly increase the aging process. Several insulation systems using either a single material or combinations of teflon, kapton, and glass insulation constructions were tested. All constructions were rated to be partial discharge and/or corona-free at 240 volts, 400 Hz and 260 C (500 F) for 50, 000 hours at altitudes equivalent to the Paschen law. Minimum partial discharge aging tests were preceded by screening tests lasting 20 hours at 260 C. The aging process was accelerated by subjecting the test articles to temperatures up to 370 C (700 F) with and without partial discharges. After one month operation with continuous glow discharges surrounding the test articles, most insulation systems were either destroyed or became brittle, cracked, and unsafe for use. Time with space radiation as with partial discharges is accumulative.

Dunbar, William G.

1995-11-01

133

Testing accelerated weathering tests for appropriate weathering chemistry: Ozone filtered xenon arc  

Microsoft Academic Search

Ftir spectroscopy has been used to follow the weathering chemistry of a HALS and UVA free polyester\\/urethane and a HALS and UVA\\u000a free acrylic\\/melamine clearcoat cured on silicon wafers and subjected to exposure in Florida, Arizona, and in a number of\\u000a accelerated weathering tests. All accelerated tests except EMMAQUA-NTW, ozone filtered xenon arc, and 3M Proprietary exposures\\u000a distort the polyester\\/urethanes

J. L. Gerlock; C. A. Peters; A. V. Kucherov; T. Misovski; C. M. Seubert; R. O. Carter; M. E. Nichols

2003-01-01

134

GTA (ground test accelerator) Phase 1: Baseline design report  

SciTech Connect

The national Neutral Particle Beam (NPB) program has two objectives: to provide the necessary basis for a discriminator/weapon decision by 1992, and to develop the technology in stages that lead ultimately to a neutral particle beam weapon. The ground test accelerator (GTA) is the test bed that permits the advancement of the state-of-the-art under experimental conditions in an integrated automated system mode. An intermediate goal of the GTA program is to support the Integrated Space Experiments, while the ultimate goal is to support the 1992 decision. The GTA system and each of its major subsystems are described, and project schedules and resource requirements are provided. (LEW)

Not Available

1986-08-01

135

Database requirements for the Advanced Test Accelerator project  

SciTech Connect

The database requirements for the Advanced Test Accelerator (ATA) project are outlined. ATA is a state-of-the-art electron accelerator capable of producing energetic (50 million electron volt), high current (10,000 ampere), short pulse (70 billionths of a second) beams of electrons for a wide variety of applications. Databasing is required for two applications. First, the description of the configuration of facility itself requires an extended database. Second, experimental data gathered from the facility must be organized and managed to insure its full utilization. The two applications are intimately related since the acquisition and analysis of experimental data requires knowledge of the system configuration. This report reviews the needs of the ATA program and current implementation, intentions, and desires. These database applications have several unique aspects which are of interest and will be highlighted. The features desired in an ultimate database system are outlined. 3 references, 5 figures.

Chambers, F.W.

1984-11-05

136

Commissioning of the Ground Test Accelerator Intertank Matching Section  

SciTech Connect

The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H{sup {minus}} beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on-line. The commissioning stages are the 35 keV H{sup {minus}} injector, the 2.5 MeV Radio Frequency Quadrupole (RFQ), the Intertank Matching Section (IMS), the 3.2 MeV first 2{beta}{gamma} Drift Tube Linac (DTL-1) module, the 8.7 MeV 2{beta}{gamma} DTL (modules 1--5), and the 24 MeV GTA; all 10 DTL modules. Commissioning results from the IMS beam experiments will be presented.

Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Cole, R.; Connolly, R.; Gilpatrick, J.D.; Ingalls, W.B.; Kersteins, D.; Little, C.; Lohsen, R.A.; Lysenko, W.P.; Mottershead, C.T.; Power, J.; Rusthoi, D.P.; Sandoval, D.P.; Stevens, R.R.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

1992-01-01

137

Commissioning of the Ground Test Accelerator Intertank Matching Section  

SciTech Connect

The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H{sup {minus}} beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on-line. The commissioning stages are the 35 keV H{sup {minus}} injector, the 2.5 MeV Radio Frequency Quadrupole (RFQ), the Intertank Matching Section (IMS), the 3.2 MeV first 2{beta}{gamma} Drift Tube Linac (DTL-1) module, the 8.7 MeV 2{beta}{gamma} DTL (modules 1--5), and the 24 MeV GTA; all 10 DTL modules. Commissioning results from the IMS beam experiments will be presented.

Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Cole, R.; Connolly, R.; Gilpatrick, J.D.; Ingalls, W.B.; Kersteins, D.; Little, C.; Lohsen, R.A.; Lysenko, W.P.; Mottershead, C.T.; Power, J.; Rusthoi, D.P.; Sandoval, D.P.; Stevens, R.R.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

1992-09-01

138

Plasma Wakefield Acceleration and FACET - Facilities for Accelerator Science and Experimental Test Beams at SLAC  

ScienceCinema

Plasma wakefield acceleration is one of the most promising approaches to advancing accelerator technology. This approach offers a potential 1,000-fold or more increase in acceleration over a given distance, compared to existing accelerators. FACET, enabled by the Recovery Act funds, will study plasma acceleration, using short, intense pulses of electrons and positrons. In this lecture, the physics of plasma acceleration and features of FACET will be presented.

139

Instrumentation for accelerated life tests of concentrator solar cells.  

PubMed

Concentrator photovoltaic is an emergent technology that may be a good economical and efficient alternative for the generation of electricity at a competitive cost. However, the reliability of these new solar cells and systems is still an open issue due to the high-irradiation level they are subjected to as well as the electrical and thermal stresses that they are expected to endure. To evaluate the reliability in a short period of time, accelerated aging tests are essential. Thermal aging tests for concentrator photovoltaic solar cells and systems under illumination are not available because no technical solution to the problem of reaching the working concentration inside a climatic chamber has been available. This work presents an automatic instrumentation system that overcomes the aforementioned limitation. Working conditions have been simulated by forward biasing the solar cells to the current they would handle at the working concentration (in this case, 700 and 1050 times the irradiance at one standard sun). The instrumentation system has been deployed for more than 10?000 h in a thermal aging test for III-V concentrator solar cells, in which the generated power evolution at different temperatures has been monitored. As a result of this test, the acceleration factor has been calculated, thus allowing for the degradation evolution at any temperature in addition to normal working conditions to be obtained. PMID:21361622

Nez, N; Vzquez, M; Gonzlez, J R; Jimnez, F J; Bautista, J

2011-02-01

140

Testing Gravity and Cosmic Acceleration with Galaxy Clustering  

NASA Astrophysics Data System (ADS)

The large-scale structure contains vast amounts of cosmological information that can help understand the accelerating nature of the Universe and test gravity on large scales. Ongoing and future sky surveys are designed to test these using various techniques applied on clustering measurements of galaxies. We present redshift distortion measurements of the Sloan Digital Sky Survey II Luminous Red Galaxy sample. We find that when combining the normalized quadrupole Q with the projected correlation function wp(rp) along with cluster counts (Rapetti et al. 2010), results are consistent with General Relativity. The advantage of combining Q and wp is the addition of the bias information, when using the Halo Occupation Distribution framework. We also present improvements to the standard technique of measuring Hubble expansion rates H(z) and angular diameter distances DA(z) when using the baryonic acoustic feature as a standard ruler. We introduce clustering wedges as an alternative basis to the multipole expansion and show that it yields similar constraints. This alternative basis serves as a useful technique to test for systematics, and ultimately improve measurements of the cosmic acceleration.

Kazin, Eyal; Tinker, J.; Sanchez, A. G.; Blanton, M.

2012-01-01

141

Testing of a medical linear accelerator's computer-control system  

SciTech Connect

In August of 1987, the Radiation Oncology Center at the Mallinckrodt Institute of Radiology became the first academic-medical-center user of Varian's computer-controlled therapy accelerator, a prototype version of the 2100C. Installation was accomplished by the retrofit of a computer system to our two-year-old Clinac 1800. Being well aware of the malfunctions that occurred in other computer-controlled accelerators, we took extraordinary measures to assure proper operation of the new, computerized, system. Our acceptance procedure included tests of (i) mechanical systems (isocentricity, digital readouts, etc.); (ii) radiation parameters (flatness, symmetry, output, etc.); (iii) manual safety systems (emergency off switches, etc.); (iv) the computer console systems (communications integrity, state integrity, etc.); and (v) the interlock systems (some 50 electrical, mechanical, and/or computer-controlled interlocks). As items (i), (ii), and (iii) do not differ significantly from the tests for a non-computer-controlled machine, they will not be discussed here. Rather, this report will concentrate on the methods that were devised to test the computer-control and interlock systems.

Weinhous, M.S.; Purdy, J.A.; Granda, C.O. (Mallinckrodt Institute of Radiology, St. Louis, Missouri 63110 (US))

1990-01-01

142

Metal and elastomer seal tests for accelerator applications  

SciTech Connect

The vacuum system of the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory has more than a thousand metal vacuum seals. Also, numerous elastomer seals are used throughout the AGS to seal large beam component chambers. An accelerator upgrade program is being implemented to reduce the AGS operating pressure by x100 and improve the reliability of the vacuum system. This paper describes work in progress on metal and elastomer vacuum seals to help meet those two objectives. Tests are reported on the sealing properties of a variety of metal seals used on different sealing surfaces. Results are also given on reversible sorption properties of certain elastomers. 16 refs., 6 figs., 4 tabs.

Welch, K.M.; McIntyre, G.T.; Tuozzolo, J.E.; Skelton, R.; Pate, D.J.; Gill, S.M.

1989-01-01

143

Development of an artificial climatic complex accelerated corrosion tester and investigation of complex accelerated corrosion test methods  

SciTech Connect

During recent decades, accelerated corrosion test equipment and methods simulating atmospheric corrosion have been developed to incorporate the many factors involved in complex accelerated corrosion. A new accelerated corrosion tester was developed to simulate various kinds of atmospheric corrosion environments. The equipment can be used to simulate various types of atmospheric corrosion environments with up to eight factors and can be used to carry out 18 kinds of standard corrosion and environmental tasks.

Li, J.; Li, M.; Sun, Z. (Beijing Inst. of Aeronautical Materials (China))

1999-05-01

144

Development of life-test sampling plans for exponential distributions based on accelerated life testing  

Microsoft Academic Search

This paper presents a procedure for developing life-test sampling plans for exponential distributions based upon accelerated life testing(ALT). Type II censoring is assumed at each overstress level. The derived test statistic is shown to be a quotient of two independent random variables, each of which is a rational power of a Chi-square random variable. The distribution of the test statistic

Bong-Jin Yum; Sun-Ho Kim

1990-01-01

145

Failure-censored accelerated life test sampling plans for Weibull distribution under expected test time constraint  

Microsoft Academic Search

This paper considers the design of life-test sampling plans based on failure-censored accelerated life tests. The lifetime distribution of products is assumed to be Weibull with a scale parameter that is a log linear function of a (possibly transformed) stress. Two levels of stress higher than the use condition stress, high and low, are used. Sampling plans with equal expected

J. G. Kim

1995-01-01

146

Analysis of Accelerated Life Test Data - Part II: Numerical Methods and Test Planning  

Microsoft Academic Search

This is Part II of a three-part series presenting statistical methods for planning and analyzing temperature-accelerated life tests with the Arrhenius model, when all test units are run to failure. These methods are presented so they can be profitably used by individuals with a limited statistical background. In Part I, the Arrhenius model is described and graphical methods for analysis

Wayne Nelosn

1972-01-01

147

Results of initial testing of the four stage RHEPP accelerator  

SciTech Connect

The low power checkout of the Repetitive High Energy Pulsed Power (RHEPP) pulse forming line (PFL) and linear induction voltage adder (LIVA) is complete. The accelerator has four LIVA cavities driven via coaxial cables from the PFL that utilizes magnetic switching to provide a 250-kV, 60-ns output pulse. The PFL is repetitively charged by a ten stage Marx generator to operate from single shot to five Hz. Results from these tests of the initial four stage RHEPP accelerator are presented and compared with design simulations. Data from a resistive cavity load and from preliminary electron diode experiments are included. While core temperatures remain low during five Hz operation, they are monitored and compared to extrapolated predictions from the design modeling. Performance of the Metglas magnetic switches and blocking cores, the voltage addition in the four LIVA cavities, and system efficiencies are discussed. Sources of discrepancies from the original design models are identified, and improved models that account for the discrepancies are presented. Improved performance potential based on these models is discussed. Plans for future testing of the 1-MV system up to 120 kW at 120 Hz and for the full system with ten LIVA cavities are presented.

Johnson, D.L.; Reed, K.W.; Harjes, H.C.

1993-08-01

148

Evaluation of accelerated stability test conditions for medicated chewing gums.  

PubMed

The overall stability of medicated chewing gums is investigated under different storage conditions. Active substances with different chemical stabilities in solid state are chosen as model drugs. The dosage form is a three layer tablet obtained by direct compression. The gum core contains the active ingredient while the external layers are formulated to prevent gum adhesion to the punches of the tableting machine. Two accelerated test conditions (40C/75% RH and 30C/65% RH) are performed for 6 months. Furthermore, a long-term stability test at room conditions is conducted to verify the predictability of the results obtained from the stress tests. Some drugs are stable in all the conditions tested, but other drugs, generally considered stable in solid dosage forms, have shown relevant stability problems particularly when stress test conditions are applied to this particular semi-solid dosage forms. For less stable drugs, the stress conditions of 40C/75% RH are not always predictable of chewing gum stability at room temperature and may produce false negative; intermediate conditions, 30C/65% RH, are more predictive for this purpose, the results of drug content found after 6 months at intermediate stress conditions and 12 months at room conditions are generally comparable. But the results obtained show that only long-term conditions stability tests gave consistent results. During aging, the semi solid nature of the gum base itself, may also influence the drug delivery rate during chewing and great attention should be given also to the dissolution stability. PMID:22794248

Maggi, Lauretta; Conte, Ubaldo; Nhamias, Alain; Grenier, Pascal; Vergnault, Guy

2012-07-16

149

Using Accelerated Testing To Predict Module Reliability: Preprint  

SciTech Connect

Long-term reliability is critical to the cost effectiveness and commercial success of photovoltaic (PV) products. Today most PV modules are warranted for 25 years, but there is no accepted test protocol to validate a 25-year lifetime. The qualification tests do an excellent job of identifying design, materials, and process flaws that are likely to lead to premature failure (infant mortality), but they are not designed to test for wear-out mechanisms that limit lifetime. This paper presents a method for evaluating the ability of a new PV module technology to survive long-term exposure to specific stresses. The authors propose the use of baseline technologies with proven long-term field performance as controls in the accelerated stress tests. The performance of new-technology modules can then be evaluated versus that of proven-technology modules. If the new-technology demonstrates equivalent or superior performance to the proven one, there is a high likelihood that they will survive versus the tested stress in the real world.

Wohlgemuth, J. H.; Kurtz, S.

2011-07-01

150

Elevated temperature accelerated release testing of PLGA microspheres.  

PubMed

Drug release from four different poly(lactic-co-glycolic) acid (PLGA) microsphere formulations was evaluated under "real-time" (37 degrees C) and accelerated release testing conditions of elevated temperature (45, 53, 60 and 70 degrees C) and increase in flow rate (4-35 ml/min) using United States Pharmacopeia (USP) apparatus 4. Formulation 5 K (composed of low Mw PLGA) exhibited diffusion-controlled kinetics in "real-time". Whereas, formulations 25 K, 28 K and 70 K (composed of medium and high Mw PLGA) followed erosion-controlled kinetics at 37 degrees C. Temperature-induced degradation of the microspheres was studied by monitoring drug release rates, change in molecular weight and morphological changes. Drug release rates at elevated temperature were used to predict "real-time" release applying the Arrhenius equation. The energy of activation for dexamethasone release from PLGA microspheres was calculated as 19.14 kcal/mol. Molecular weight change measured by gel permeation chromatography followed first order kinetics for both "real-time" and accelerated release. All four formulations exhibited morphological changes (such as surface pore closing and geometry change) at elevated temperature with consequent reduction in burst release. PMID:16644055

Zolnik, Banu S; Leary, Pauline E; Burgess, Diane J

2006-04-27

151

Lessons learned on the Ground Test Accelerator control system  

SciTech Connect

When we initiated the control system design for the Ground Test Accelerator (GTA), we envisioned a system that would be flexible enough to handle the changing requirements of an experimental project. This control system would use a developers` toolkit to reduce the cost and time to develop applications for GTA, and through the use of open standards, the system would accommodate unforeseen requirements as they arose. Furthermore, we would attempt to demonstrate on GTA a level of automation far beyond that achieved by existing accelerator control systems. How well did we achieve these goals? What were the stumbling blocks to deploying the control system, and what assumptions did we make about requirements that turned out to be incorrect? In this paper we look at the process of developing a control system that evolved into what is now the ``Experimental Physics and Industrial Control System`` (EPICS). Also, we assess the impact of this system on the GTA project, as well as the impact of GTA on EPICS. The lessons learned on GTA will be valuable for future projects.

Kozubal, A.J.; Weiss, R.E.

1994-09-01

152

Life time prediction for lead-free solder joints under vibration loads  

Microsoft Academic Search

In this work the life time of solder joints of SMD components is studied under vibration loading. This kind of purely mechanical load is one of the main failure causes in automotive electronics. A test vehicle has been designed to enable vibration testing on SMD capacitors (size 0805). The test vehicle is distinguished with a line clamping and stripe shape

Karsten Meier; Mike Roelligl; Andreas Schiessl; Klaus-Juergen Wolter

2011-01-01

153

A flexible and configurable system to test accelerator magnets  

SciTech Connect

Fermilab's accelerator magnet R and D programs, including production of superconducting high gradient quadrupoles for the LHC insertion regions, require rigorous yet flexible magnetic measurement systems. Measurement systems must be capable of handling various types of hardware and extensible to all measurement technologies and analysis algorithms. A tailorable software system that satisfies these requirements is discussed. This single system, capable of distributed parallel signal processing, is built on top of a flexible component-based framework that allows for easy reconfiguration and run-time modification. Both core and domain-specific components can be assembled into various magnet test or analysis systems. The system configured to comprise a rotating coil harmonics measurement is presented. Technologies as Java, OODB, XML, JavaBeans, software bus and component-based architectures are used.

Jerzy M. Nogiec et al.

2001-07-20

154

The Status of Turkish Accelerator Center Test Facility  

SciTech Connect

Recently, conceptual design of Turkic Accelerator Center (TAC) proposal was completed. Main goal of this proposal is a charm factory that consists of a linac-ring type electron-positron collider. In addition, synchrotron radiation from the positron ring and free electron laser from the electron linac are proposed. The project related with this proposal has been accepted by Turkish government. It is planned that the Technical Design Report of TAC will have been written in next three years. In this period, an infrared oscillator free electron laser (IR FEL) will be constructed as a test facility for TAC. 20 and 50 MeV electron energies will be used to obtain infra red free electron laser. The main parameters of the electron linac, the optical cavities and the free electron laser were determined. The possible use of obtained laser beam in basic and applied research areas such as biotechnology, nanotechnology, semiconductors and photo chemistry were stated.

Yavas, Oe. [University of Ankara, Fac. of Engineering, Dept. of Engineering Physics, Tandogan 06100, Ankara (Turkey)

2007-04-23

155

Vibrational Stability of SRF Accelerator Test Facility at Fermilab  

SciTech Connect

Recently developed, the Superconducting Radio Frequency (SRF) Accelerator Test Facilities at Fermilab support the International Linear Collider (ILC), High Intensity Neutrino Source (HINS), a new high intensity injector (Project X) and other future machines. These facilities; Meson Detector Building (MDB) and New Muon Lab (NML) have very different foundations, structures, relative elevations with respect to grade level and surrounding soil composition. Also, there are differences in the operating equipment and their proximity to the primary machine. All the future machines have stringent operational stability requirements. The present study examines both near-field and ambient vibration in order to develop an understanding of the potential contribution of near-field sources (e.g. compressors, ultra-high and standard vacuum equipment, klystrons, modulators, utility fans and pumps) and distant noise sources to the overall system displacements. Facility vibration measurement results and methods of possible isolation from noise sources are presented and discussed.

McGee, M.W.; Volk, J.T.; /Fermilab

2009-05-01

156

Beam Based Alignment at the KEK Accelerator Test Facility  

SciTech Connect

The KEK Accelerator Test Facility (ATF) damping ring is a prototype low emittance source for the NLC/JLC linear collider. To achieve the goal normalized vertical emittance {gamma}{var_epsilon}{sub y} = 20 nm-rad, magnet placement accuracy better than 30 mm must be achieved. Accurate beam-based alignment (BBA) is required. The ATF arc optics uses a FOBO cell with two horizontally focusing quadrupoles, two sextupoles and a horizontally defocusing gradient dipole, all of which must be aligned with BBA. BBA at ATF uses the quadrupole and sextupole trim windings to find the trajectory through the center of each magnet. The results can be interpreted to assess the accuracy of the mechanical alignment and the beam position monitor offsets.

Ross, Marc C

2002-07-03

157

Beam based alignment at the KEK accelerator test facility  

SciTech Connect

The KEK Accelerator Test Facility (ATF) damping ring is a prototype low emittance source for the NLC/JLC linear collider. To achieve the goal normalized vertical emittance {gamma}{var_epsilon}{sub {gamma}} = 20 nm-rad, magnet placement accuracy better than 30 mm must be achieved. Accurate beam-based alignment (BBA) is required. The ATF arc optics uses a FOBO cell with two horizontally focusing quadrupoles, two sextupoles and a horizontally defocusing gradient dipole, all of which must be aligned with BBA. BBA at ATF uses the quadrupole and sextupole trim windings to find the trajectory through the center of each magnet. The results can be interpreted to assess the accuracy of the mechanical alignment and the beam position monitor offsets.

Ross, M.; Nelson, J.; Woodley, M.; Wolski, A.

2002-06-14

158

The test pulse line ion accelerator in Lanzhou  

Microsoft Academic Search

To accelerate intense, short pulsed heavy ion beams to the energies of interest for studies of high energy density physics and warm dense matter, the Pulse Line Ion Accelerator (PLIA), of which the axial acceleration gradient can achieve several MeV per meter with realistic helix parameters at very low cost, was developed in recent years. A simple prototype of PLIA

Shen Xiao-Kang; Cao Shu-Chun; Zhang Zi-Min; Zhao Hong-Wei; Zhao Quan-Tang; Liu Ming; Jing Yi; Li Zhong-Ping; Wan Ming; Wang Bin; Yang Chun-Ming; Xiao Rong-Qing; Zhang Ying-Fa; Li Ji-An

2012-01-01

159

A statistical comparison of accelerated concrete testing methods  

Microsoft Academic Search

Accelerated curing results, obtained after only 24 hours, are used to predict the 28 day strength of concrete. Various accelerated curing methods are available. Two of these methods are compared in relation to the accuracy of their predictions and the stability of the relationship between their 24 hour and 28 day concrete strength. The results suggest that Warm Water accelerated

Denny Meyer

1997-01-01

160

Accelerated corrosion tests for aerospace materials: current limitations and future trends  

Microsoft Academic Search

Examines accelerated methods for the corrosion testing of materials, coatings and surface treatments used in the aerospace and defence industries. The drawbacks with some current accelerated corrosion tests are examined, particularly the problems experienced with neutral salt spray tests. Specific examples are given which identify the acute discrepancy between salt spray and marine exposure in the corrosion testing of metallic

K. R. Baldwin; C. J. E. Smith

1999-01-01

161

Accelerated indoor durability testing of polymeric photovoltaic encapsulation materials  

NASA Astrophysics Data System (ADS)

The aim of these investigations was to determine the influence of the relevant load parameters temperature and humidity on the degradation behavior of selected polymeric PV encapsulation materials. A test program concerning three accelerated artificial ageing tests was set up and a comprehensive study of the selected candidate materials and its degradation behavior was done. To assess the long term performance and durability of materials, it was necessary not only to measure the deterioration of macroscopic physical properties, but also to gain information about degradation processes taking place at a molecular level. Therefore, the material properties and the aging behaviour were characterized by infrared spectroscopy, by UV/VIS spectroscopy, by differential scanning calorimetry, by dynamical mechanical analysis and by tensile tests. By IR spectroscopy no significant thermal oxidation was detected for all investigated materials. But UV/VIS spectroscopy showed a significant drop in solar transmittance and reflectance values. Yellowing was observed due to the formation of chromophoric degradation products. For all materials a significant decrease in ultimate mechanical properties due to chemical aging was measured. For both backsheet materials the changes in ultimate mechanical properties can be attributed nearly exclusiveley to the polyester layer. On the other hand, a stiffening of all materials due to physical aging was observed within the first 1000h of damp heat testing. For the backsheet laminates, delamination at the edges was observed. Generally, higher temperature levels during exposure induced faster rate of chemical and physical aging. High humidity levels showed to be less influential on polymer degradation than temperature.

Oreski, Gernot

2010-08-01

162

Degradation mechanisms and accelerated testing in PEM fuel cells  

SciTech Connect

The durability of PEM fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. Although there has been recent progress in improving durability, further improvements are needed to meet the commercialization targets. Past improvements have largely been made possible because of the fundamental understanding of the underlying degradation mechanisms. By investigating component and cell degradation modes; defining the fundamental degradation mechanisms of components and component interactions new materials can be designed to improve durability. Various factors have been shown to affect the useful life of PEM fuel cells. Other issues arise from component optimization. Operational conditions (such as impurities in either the fuel and oxidant stream), cell environment, temperature (including subfreezing exposure), pressure, current, voltage, etc.; or transient versus continuous operation, including start-up and shutdown procedures, represent other factors that can affect cell performance and durability. The need for Accelerated Stress Tests (ASTs) can be quickly understood given the target lives for fuel cell systems: 5000 hours ({approx} 7 months) for automotive, and 40,000 hrs ({approx} 4.6 years) for stationary systems. Thus testing methods that enable more rapid screening of individual components to determine their durability characteristics, such as off-line environmental testing, are needed for evaluating new component durability in a reasonable turn-around time. This allows proposed improvements in a component to be evaluated rapidly and independently, subsequently allowing rapid advancement in PEM fuel cell durability. These tests are also crucial to developers in order to make sure that they do not sacrifice durability while making improvements in costs (e.g. lower platinum group metal [PGM] loading) and performance (e.g. thinner membrane or a GDL with better water management properties). To achieve a deeper understanding and improve PEM fuel cell durability LANL is conducting research to better define fuel cell component degradation mechanisms and correlate AST measurements to component in 'real-world' situations.

Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory

2010-01-01

163

Accelerated atmospheric corrosion testing of electroplated gold mirror coatings  

NASA Astrophysics Data System (ADS)

Gold-coated mirrors are widely used in infrared optics for industrial, space, and military applications. These mirrors are often made of aluminum or beryllium substrates with polished nickel plating. Gold is deposited on the nickel layer by either electroplating or vacuum deposition processes. Atmospheric corrosion of gold-coated electrical connectors and contacts was a well-known problem in the electronic industry and studied extensively. However, there is limited literature data that correlates atmospheric corrosion to the optical properties of gold mirror coatings. In this paper, the atmospheric corrosion of different electroplated gold mirror coatings were investigated with an accelerated mixed flowing gas (MFG) test for up to 50 days. The MFG test utilizes a combination of low-level air pollutants, humidity, and temperatures to achieve a simulated indoor environment. Depending on the gold coating thickness, pore corrosion started to appear on samples after about 10 days of the MFG exposure. The corrosion behavior of the gold mirror coatings demonstrated the porous nature of the electroplated gold coatings as well as the variation of porosity to the coating thickness. The changes of optical properties of the gold mirrors were correlated to the morphology of corrosion features on the mirror surface.

Chu, C.-T.; Alaan, D. R.; Taylor, D. P.

2010-08-01

164

Inverse Cherenkov and inverse FEL accelerator experiments at the Brookhaven Accelerator Test Facility  

SciTech Connect

Status update on the ongoing inverse Cherenkov acceleration experiment and prospects to its 100 MeV short-term upgrade. The first report on 1 MeV electron acceleration with the 0.5 GW CO{sub 2} laser used in the inverse FEL scheme. (author). 22 refs., 8 figs., 1 tab.

Pogorelsky, I.V.; vanSteenbergen, A.; Babzien, M.

1995-12-31

165

Acceleration tests to determine salient pole synchronous motor inrush currents and torques  

Microsoft Academic Search

Determining torque and current at locked rotor and various slips during the acceleration test on a synchronous machine is very tedious and time consuming. Induction and synchronous machines behave similarly during acceleration except that synchronous machine acceleration can include a pulsation torque. Because of the salient poles, conditions exist where the synchronous motor has minimum torque at quadrature axis and

J. H. Dymond; B. Mistry; R. Ong

2002-01-01

166

A physics-of-failure (POF) approach to addressing device reliability in accelerated testing of MCMs  

Microsoft Academic Search

The physics-of-failure testing approach for multichip modules presented in this paper determines test levels based on failure mechanisms, failure modes, and stresses for the application. It uses quantitative failure models and acceleration transforms and adapts the knowledge of dominant failure mechanisms to the selection of accelerating stress parameters. The stress levels, designed specifically for each test article, are based on

John Evans; Michael J. Cushing; Pradeep Lall; Richard Bauernschub

1995-01-01

167

Analysis of Accelerated Life Test Data-Least Squares Methods for the Inverse Power Law Model  

Microsoft Academic Search

This expository paper presents simple least squares methods for analyzing accelerated life test data with the inverse power law model, when all test units are run to failure. These methods are illustrated with accelerated test data on time to break-down of an insulating fluid.

Wayne Nelson; Reader Aids

1975-01-01

168

Design of accelerated corrosion tests for electronic components in automotive applications  

Microsoft Academic Search

Two new accelerated laboratory corrosion tests for electronic components in automotive applications have been developed, based on the use of metallic copper as a meter for corrosivity. The accelerated tests are designed so that they reproduce the same kind of corrosion effects as observed with exposure of copper in real vehicle environments. The test cycle that best simulates the corrosion

Peter Eriksson; Bo Carlsson; I. O. Wallinder

2001-01-01

169

Acceleration  

Microsoft Academic Search

IN NATURE, NO. 1415, p. 125, Prof. Lodge asserts that the subject of acceleration is at the root of the perennial debate between engineers and teachers of mechanics; and he urges clearness of idea and accuracy of speech on all who deal with the junior student. Towards this end I would suggest that the too common phrase ``acceleration of velocity''

Edward Geoghegan

1897-01-01

170

Demonstration recommendations for accelerated testing of concrete decontamination methods  

SciTech Connect

A large number of aging US Department of Energy (DOE) surplus facilities located throughout the US require deactivation, decontamination, and decommissioning. Although several technologies are available commercially for concrete decontamination, emerging technologies with potential to reduce secondary waste and minimize the impact and risk to workers and the environment are needed. In response to these needs, the Accelerated Testing of Concrete Decontamination Methods project team described the nature and extent of contaminated concrete within the DOE complex and identified applicable emerging technologies. Existing information used to describe the nature and extent of contaminated concrete indicates that the most frequently occurring radiological contaminants are {sup 137}Cs, {sup 238}U (and its daughters), {sup 60}Co, {sup 90}Sr, and tritium. The total area of radionuclide-contaminated concrete within the DOE complex is estimated to be in the range of 7.9 {times} 10{sup 8} ft{sup 2}or approximately 18,000 acres. Concrete decontamination problems were matched with emerging technologies to recommend demonstrations considered to provide the most benefit to decontamination of concrete within the DOE complex. Emerging technologies with the most potential benefit were biological decontamination, electro-hydraulic scabbling, electrokinetics, and microwave scabbling.

Dickerson, K.S.; Ally, M.R.; Brown, C.H.; Morris, M.I.; Wilson-Nichols, M.J.

1995-12-01

171

Accelerated cyclic corrosion testing of structural steels and its application to assess steel bridge coatings  

Microsoft Academic Search

Purpose The purpose of this study was to determine correlation between an accelerated cyclic corrosion test (S6-cycle test) specified in Japanese Industrial Standards K5621 and field exposure tests, and to open up applications of the accelerated tests in various regional environments. Design\\/methodology\\/approach The S6-cycle corrosion test was carried out on structural steels for 30, 60, 90, 120 and

Yoshito Itoh; In-Tae Kim

2006-01-01

172

High Power Testing of a Fused Quartz-Based Dielectric-Loaded Accelerating Structure.  

National Technical Information Service (NTIS)

We report on the most recent results from a series of high power tests being carried out on rf-driven dielectric loaded accelerating (DLA) structures. The purpose of these tests is to determine the viability of the DLA as a traveling-wave accelerator and ...

C. Jing J. G. Power R. Konecny W. Gai Z. Yusof

2007-01-01

173

Development of a 20-MeV Dielectric-Loaded Accelerator Test Facility  

SciTech Connect

This paper describes a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), to develop a dielectric-loaded accelerator (DLA) test facility powered by a high-power 11.424-GHz magnicon amplifier. The magnicon can presently produce 25 MW of output power in a 250-ns pulse at 10 Hz, and efforts are in progress to increase this to 50 MW. The facility will include a 5 MeV electron inector being developed by the Accelerator Laboratory of Tsinghua University in Beijing, China. The DLA test structures are being developed by ANL, and some have undergone testing at NRL at gradients up to {approx} 8 MV/m. SLAC is developing a means to combine the two magnicon output arms, and to drive an injector and accelerator with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRl, is developing a means to join short ceramic sections into a continuous accelerator tube by ceramic brazing using an intense millimeter-wave beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year. The facility will be used for testing DLA structures using a variety of materials and configurations, and also for testing other X-band accelerator concepts. The initial goal is to produce a compact 20 MeV dielectric-loaded test accelerator.

Gold, S.H.; Kinkead, A.K.; Gai, W.; Power, J.G.; Konecny, R.; Jing, C.G.; Tantawi, S.G.; Nantista, C.D.; Hu, Y.; Chen, H.; Tang, C.; Lin, Y.; Bruce, R.W.; Bruce, R.L.; Fliflet, A.W.; Lewis, D.; /Naval Research Lab, Wash., D.C. /LET Corp., Washington /Argonne /SLAC /Tsinghua U., Beijing

2005-06-22

174

Accelerated life testing design based on wear failure mechanism for pneumatic cylinders  

Microsoft Academic Search

The piston and piston pole sealing ring are the weak units as well as leakage sources which easily result in the cylinders failure. The primary criterion for determining test acceleration factors is that the failure mode or failure mechanism should not change or be different from that expected from a non-accelerated test. Working temperature, frequency and motion velocity are chosen

Juan Chen; Qiang Wu; Guochang Bai; Jungong Ma; Zhanlin Wang

2009-01-01

175

A Comparison of Accelerated Life Test Plans for Weibull and Lognormal Distributions and Type I Censoring  

Microsoft Academic Search

Previous work on planning accelerated life test plans for the Weibull and lognormal distributions has concentrated on optimum test plans that minimize the variance of some specified estimator. However, these test plans use tests at only two levels of stress and, thus, have serious practical limitations. This article compares optimum test plans and some compromise test plans with respect to

William Q. Meeker

1984-01-01

176

Field Operations Program Chevrolet S-10 (Lead-Acid) Accelerated Reliability Testing - Final Report.  

National Technical Information Service (NTIS)

This report summarizes the Accelerated Reliability testing of five lead-acid battery-equipped Chevrolet S-10 electric vehicles by the US Department of Energy's Field Operations Program and the Program's testing partners, Electric Transportation Applicatio...

J. Francfort J. Argueta M. Wehrey D. Karner L. Tyree

1999-01-01

177

Acceleration Test of Radioactive Nuclear Beam at INS  

NASA Astrophysics Data System (ADS)

An ISOL based radioactive-beam facility has been constructed at INS. The purpose of this facility is to study various technical problems of the Exotic Nuclear Arena in the Japanese Hadron Project(JHP) and to perform experiments of astrophysical interest. Unstable nuclei produced by bombarding a thick target with 30-40 MeV protons or light-ions from the existing SF cyclotron are ionized in ISOL ion sources (ECR, Surface Ionization, Plasma), mass analyzed by an ISOL (M/? M <= 9000), and injected to the following accelerator complex through a 60m long beam transport line. The accelerator complex consists of a Split Coaxial RFQ(172keV/u), and an Interdigital-H linac(1MeV/u) and a matching section between these linacs. At the end of last year, we tried to accelerate stable ^20Ne^2+ beam from the ISOL ion source in order to check the whole system in this facility. The beam was successfully accelerated and transported at the target position placed downstream from the IH linac. First acceleration of unstable nuclei is scheduled in this spring. These results are reported in this paper.

Tomizawa, M.; Arai, S.; Arakaki, Y.; Hashimoto, Y.; Imanishi, A.; Jeong, S. C.; Katayama, I.; Katayama, T.; Kawakami, H.; Kubono, S.; Miyachi, T.; Miyatake, H.; Niki, K.; Nomura, T.; Okada, M.; Oyaizu, M.; Shirakabe, Y.; Strasser, P.; Takeda, Y.; Tanaka, J.; Tanaka, M. H.; Tojyo, E.; Wada, M.

1997-05-01

178

Experimental test accelerator: description and results of initial experiments  

SciTech Connect

The ETA is a high current (10,000 Amp) linear induction accelerator that produces short (30 ns) pulses of electrons at 5 MeV twice per second or in bursts of 5 pulses separated by as little as one millisecond. At this time the machine has operated at 65% of its design current and 90% of the design voltage. This report contains a description of the accelerator and its diagnostics; the results of the initial year of operation; a comparison of design codes with experiments on beam transport; and a discussion of some of the special problems and their status.

Fessenden, T.; Birx, D.; Briggs, R.

1980-06-02

179

Development of an accelerated leach test(s) for low-level waste forms  

SciTech Connect

An accelerated leach test(s) is being developed to predict long-term leaching behavior of low-level radioactive waste (LLW) forms in their disposal environments. As necessary background, a literature survey of reported leaching mechanisms, available mathematical models and factors that affect leaching of LLW forms has been compiled. Mechanisms which have been identified include diffusion, dissolution, ion exchange, corrosion and surface effects. A computerized data base of LLW leaching data and mathematical models is being developed. The data is being used for model evaluation by curve fitting and statistical analysis according to standard procedures of statistical quality control. Long-term leach tests on portland cement, bitumen and vinyl ester-styrene (VES) polymer waste forms are underway which are designed to identify and evaluate factors that accelerate leaching without changing the mechanisms. Initial results on the effect of temperature on leachability indicate that the leach rates of cement and VES waste forms increase with increasing temperature, whereas, the leach rate of bitumen is little affected. 10 refs., 5 figs.

Dougherty, D.R.; Fuhrmann, M.; Colombo, P.

1985-01-01

180

Use of E. M. Accelerators in High Pressure Test Facilities.  

National Technical Information Service (NTIS)

The performance of steady-state axisymmetric accelerators is investigated under the assumption that they tend to operate in a minimum potential mode. The existence of a 'critical' or Alfven exhaust velocity and of a critical mass flow rate is shown to fol...

G. L. Cann

1972-01-01

181

An Automatic Machine for Accelerated Weathering Tests on Concrete  

Microsoft Academic Search

The machine described has been designed for accelerated weathering of concrete surfaces. Its basis is a turntable on a vertical axis, carrying concrete exposure specimens which are subjected to the action of smoke, water sprays, cooling elements and heating elements. The machine accommodates 32 specimen slabs of concrete each measuring 2 ft. 1 ft. 2 in., and by

W R Crawford; L J Murdock

1943-01-01

182

Use of the LEDA Facility as an ADS High-Power Accelerator Test Bed  

Microsoft Academic Search

The Low-Energy Demonstration Accelerator (LEDA) was built to generate high-current proton beams. Its successful full-power operation and testing in 1999-2001 confirmed the feasibility of a high-power linear accelerator (linac) front end, the most technically challenging portion of such a machine. The 6.7-MeV accelerator operates reliably at 95-mA CW beam current with few interruptions orjaults, and qualiJes as one of the

R. W. Garnett; R. L. Sheffield

2003-01-01

183

Results of an accelerated borehole closure testing program at Avery Island: Topical report RSI-0211  

SciTech Connect

This report presents the results of an accelerated borehole closure testing program conducted in the ONWI test facility in the Avery Island salt mine. The accelerated borehole closure tests were a part of a field testing program at Avery Island to provide data on the thermomechanical response of domal salt when subjected to conditions similar to those expected in a high-level nuclear waste repository. The primary objective of the accelerated borehole closure test is to provide data that can be used for validation of the numerical methods used to predict the creep behavior of salt. Two series of accelerated borehole closure tests were performed. The first of these (Phase I) was conducted during 1980, and the second (Phase II) was conducted during 1981 and 1982. 5 refs., 19 figs., 2 tabs.

Stickney, R.G.

1985-04-01

184

Operational status of the Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

Design and operation of a 50 MeV Electron Linear Accelerator utilizing a low emittance ({gamma} {var epsilon} = 5 to 10 mm-mrad) radio frequency gun operating at an output energy of 5 MeV and a charge of 1 nC is described. Design calculations and early radio frequency measurements and operational experience with the electron gun utilizing a dummy copper cathode in place of the proposed photocathode emitter are given. 6 refs., 9 figs., 1 tab.

Batchelor, K.; Ben-Zvi, I.; Chou, T.S.; Fernow, R.C.; Fischer, J.; Gallarado, J.; Kirk, H.G.; Palmer, R.B.; Pellegrini, C.; Sheehan, J.; Srinivasan-Rao, T.; Ulc, S.; Van Steenbergen, A.; Woodle, M.; Biglio, I.; Kurnit, N.; McDonald, K.T. (Brookhaven National Lab., Upton, NY (USA); Los Alamos National Lab., NM (USA); Princeton Univ., NJ (USA). Dept. of Physics)

1989-01-01

185

A review of accelerated stress tests of MEA durability in PEM fuel cells  

Microsoft Academic Search

This paper is a review of recent work done on accelerated stress tests in the study of PEM fuel cell durability, with a primary focus on the main components of the membrane electrode assembly (MEA). The accelerated stressors for each component under different conditions are outlined, in an attempt to gain a detailed understanding of cell degradation with respect to

Shengsheng Zhang; Xiaozi Yuan; Haijiang Wang; Walter Mrida; Hong Zhu; Jun Shen; Shaohong Wu; Jiujun Zhang

2009-01-01

186

Comparison of two instruments for accelerated weathering tests on plasticized PVC  

Microsoft Academic Search

Various PVC textile coatings have been comparatively tested in QUV and Weather-O-Meter (WOM) accelerated weathering chambers and in Florida tropical climate. The degradation has been measured by the variation of the IR optical density at 1780 cm?1. For all samples the WOM weathering is representative of the different forms of outdoor weathering degradation with an acceleration factor of some units.

Emmanuelle Mathieu; Jean-Louis Laurent

1996-01-01

187

Accelerated Life Test Planning With Independent Weibull Competing Risks With Known Shape Parameter  

Microsoft Academic Search

This article presents methodology for accelerated life test (ALT) planning when there are two or more failure modes, or competing risks which are dependent on one accelerating factor. It is assumed that the failure modes have respective latent (unobservable) failure times, and the minimum of these times corresponds to the product lifetime. The latent failure times are assumed to be

Francis G. Pascual

2007-01-01

188

Development of a 20 MeV Dielectric-Loaded Test Accelerator  

SciTech Connect

This paper presents a progress report on a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), to develop a dielectric-loaded test accelerator in the magnicon facility at NRL. The accelerator will be powered by an experimental 11.424-GHz magnicon amplifier that presently produces 25 MW of output power in a {approx}250-ns pulse at up to 10 Hz. The accelerator will include a 5-MeV electron injector originally developed at the Tsinghua University in Beijing, China, and can incorporate DLA structures up to 0.5 m in length. The DLA structures are being developed by ANL, and shorter test structures fabricated from a variety of dielectric materials have undergone testing at NRL at gradients up to {approx}8 MV/m. SLAC has developed components to distribute the power from the two magnicon output arms to the injector and to the DLA accelerating structure with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRL, has investigated means to join short ceramic sections into a continuous accelerator tube by a brazing process using an intense 83-GHz beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA test structure, and spectrometer, should take place within the next year.

Gold, S.H.; Kinkead, A.K.; Gai, W.; Power, J.G.; Konecny, R.; Jing, C.; Long, J.; Tantawi, S.G.; Nantista, C.D.; Fliflet, A.W.; Lombardi, M.; Lewis, D.; /Naval Research Lab, Wash., D.C. /LET Corp., Washington /Argonne /Euclid Techlabs, Solon /SLAC; Bruce, R.W.; /Unlisted

2007-04-13

189

History of Accelerated and Qualification Testing of Terrestrial Photovoltaic Modules: A Literature Review  

SciTech Connect

We review published literature from 1975 to the present for accelerated stress testing of flat-plate terrestrial photovoltaic (PV) modules. An important facet of this subject is the standard module test sequences that have been adopted by national and international standards organizations, especially those of the International Electrotechnical Commission (IEC). The intent and history of these qualification tests, provided in this review, shows that standard module qualification test results cannot be used to obtain or infer a product lifetime. Closely related subjects also discussed include: other limitations of qualification testing, definitions of module lifetime, module product certification, and accelerated life testing.

Osterwald, C. R.; McMahon, T. J.

2009-01-01

190

First High Power Test Results for 2.1 GHz Superconducting Photonic Band Gap Accelerator Cavities  

NASA Astrophysics Data System (ADS)

We report the results of the recent high power testing of superconducting radio frequency photonic band gap (PBG) accelerator cells. Tests of the two single-cell 2.1 GHz cavities were performed at both 4 and 2 K. An accelerating gradient of 15MV/m and an unloaded quality factor Q0 of 4109 were achieved. It has been long realized that PBG structures have great potential in reducing long-range wakefields in accelerators. A PBG structure confines the fundamental TM01-like accelerating mode, but does not support higher order modes. Employing PBG cavities to filter out higher order modes in superconducting particle accelerators will allow suppression of dangerous beam instabilities caused by wakefields and thus operation at higher frequencies and significantly higher beam luminosities. This may lead towards a completely new generation of colliders for high energy physics and energy recovery linacs for the free-electron lasers.

Simakov, Evgenya I.; Haynes, W. Brian; Madrid, Michael A.; Romero, Frank P.; Tajima, Tsuyoshi; Tuzel, Walter M.; Boulware, Chase H.; Grimm, Terry L.

2012-10-01

191

The Significance of Cumulative Coriolis Acceleration for Tests for Expert Medical Selection.  

National Technical Information Service (NTIS)

The results of the test for cumulation of coriolis accelerations in 376 men: 269 healthy and 107 with various somatic pathology are presented. Action tolerance was assessed by the 9data of clinical observations, ECG, arterial pressure, results of neuropat...

I. Y. Yakovleva V. P. Baranova E. I. Matsnev A. Y. Tizul

1974-01-01

192

Experimental Evaluation of the Battelle Accelerated Test Design for the Solar Array at Mead, Nebraska.  

National Technical Information Service (NTIS)

A previously developed test design for accelerated aging of photovoltaic modules was experimentally evaluated. The studies included a review of relevant field experience, environmental chamber cycling of full size modules, and electrical and physical eval...

P. O. Frickland J. Repar

1982-01-01

193

Application of Full-Scale Accelerated Pavement Testing. A Synthesis of Highway Practice.  

National Technical Information Service (NTIS)

This synthesis, which describes the state of the practice for full-scale accelerated pavement testing (APT), will be of interest to state department of transportation (DOT) pavement design and materials engineers; DOT research staff, including field and l...

J. B. Metcalf

1996-01-01

194

Accelerated Laboratory Corrosion Test for Materials and Finishes Used in Naval Aircraft.  

National Technical Information Service (NTIS)

An accelerated laboratory corrosion test has been developed to screen materials and finishes for use on naval aircraft. Sulfur dioxide is introduced at periodic intervals into a conventional salt fog chamber to simulate conditions produced by the carrier ...

S. J. Ketcham

1977-01-01

195

Effects of Accelerated Exposure Testing (AET) Conditions on Performance Degradation of Solar Cells and Encapsulants  

SciTech Connect

The paper briefly summarizes the results from several accelerated exposure tests (AET) studies. Causes responsible for the photothermal instability of the encapsulated Si solar cells appear to be multiple and complex.

Glick, S. H.; Pern, F. J.

2000-01-01

196

Analysis of Accelerated Life Test Data for Aerospace Nickel-Cadmium Cells.  

National Technical Information Service (NTIS)

A process was developed for the accelerated life testing of a particular cell or battery which comprises the comparison and extrapolation of the end of discharge voltages plotted versus the logarithm of the cycle number in combination with prior knowledge...

E. A. Roeger J. McCallum G. H. Miller

1974-01-01

197

Field Operations Program Chevrolet S-10 (Lead-Acid) Accelerated Reliability Testing - Final Report  

Microsoft Academic Search

This report summarizes the Accelerated Reliability testing of five lead-acid battery-equipped Chevrolet S-10 electric vehicles by the US Department of Energy's Field Operations Program and the Program's testing partners, Electric Transportation Applications (ETA) and Southern California Edison (SCE). ETA and SCE operated the S-10s with the goal of placing 25,000 miles on each vehicle within 1 year, providing an accelerated

J. Francfort; J. Argueta; M. Wehrey; D. Karner; L. Tyree

1999-01-01

198

Accelerated Moisture Sensitivity Test Methodology for Stacked-Die Molded Matrix Array Package  

Microsoft Academic Search

The existing IPC\\/JEDEC of moisture\\/reflow sensitivity classification determines the time of accelerated equivalent soak by the equivalency of moisture concentration at the critical interface with the standard sensitivity test. This paper proposes a new methodology of accelerated moisture sensitivity test based on the equivalency of both local moisture concentration and overall moisture distribution for stacked-die molded matrix array package (MMAP).

Bin Xie; Xunqing Shi; Xuejun Fan

2007-01-01

199

A study of erosion in die casting dies by a multiple pin accelerated erosion test  

Microsoft Academic Search

An accelerated erosion test was developed to evaluate the erosion resistance of die materials and coatings for die casting\\u000a application. An acceleration in wear was achieved by selecting pyramid-shaped core pins, hypereutectic aluminum silicon casting\\u000a alloy, high melt temperatures and high gate velocities. Multiple pin design was selected to enable multiple test sites for\\u000a comparative evaluation. Apilot run was conducted

R. Shivpuri; M. Yu; K. Venkatesan; Y.-L Chu

1995-01-01

200

Acceptance sampling plans based on failure-censored step-stress accelerated tests for Weibull distributions  

Microsoft Academic Search

Purpose The paper aims to present acceptance sampling plans based on failure-censored step-stress accelerated life tests for items having Weibull lives. Design\\/methodology\\/approach The model parameters are estimated by the method of maximum likelihood. Based on asymptotic distribution theory, the sample size and the acceptability constant are determined satisfying the producer's and consumer's risks. The step-stress accelerated life test

Sang Wook Chung; Young Sung Seo; Won Young Yun

2006-01-01

201

Evaluation of the long-term durability of yellow travertine using accelerated weathering tests  

Microsoft Academic Search

The study investigated the long-term performance\\/durability of yellow travertine against various environmental processes using\\u000a several accelerated weathering tests: wetdry, freezethaw and salt crystallization. Prior to the accelerated weathering tests,\\u000a the specimens were separated into two groups based on their porosities. The re-crystallization pressure of Na2SO4 salt was found to be the most destructive factor in the deterioration of the yellow

Mutluhan AkinAydi; Ayd?n zsan

2011-01-01

202

Prediction of outdoor weathering performance of polypropylene filaments by accelerated weathering tests  

Microsoft Academic Search

The effects of both accelerated and outdoor weathering tests on polypropylene filaments are studied to seek the possible relationship between weathering performance of the material under the two weathering conditions. Three intensities of Ultraviolet (UV) irradiation were provided in accelerated weathering tests to study the influences of UV irradiation intensity on photo-oxidation of the filaments. These are 81.58, 162.58 and

Xudong Yang; Xin Ding

2006-01-01

203

COMPARISON OF ACCELERATED CORROSION TESTS TO CORROSION PERFORMANCE IN NATURAL ATMOSPHERIC ENVIRONMENTS  

Microsoft Academic Search

There is interest in the comparison of accelerated corrosion tests to corrosion performance in natural atmospheric environments. Currently, there are some concerns that accelerated corrosion testing may not accurately predict performance in natural atmospheric environments. This provided motivation to compare the corrosion behavior of Al 1060, Al 6061-T6, Al 7075-T6, Al 2024-T3, pure copper, pure magnesium, coated pure magnesium, 1008

R. Sugamoto; G. A. Hawthorn

204

The EFI test method for accelerated growth of water trees  

Microsoft Academic Search

The philosophy behind the development of Rogowski-type test objects and the aging and test procedures used in the Norwegian Electric Power Research Institute (EFI) test method are presented. Some of the results obtained during almost eight years of the use of this method are briefly reviewed. The great advantage of the method is that a model of a cable insulation

H. Faremo; E. Ildstad

1990-01-01

205

Cold test results of a side-coupled standing-wave electron-accelerating structure  

NASA Astrophysics Data System (ADS)

The radio-frequency (RF) cavity for the dual-energy S-band electron linear accelerator (LINAC) is designed for a cargo inspection system (CIS) at the Korea Atomic Energy Research Institute (KAERI). The cold test results of the electron accelerator structure, which has a side-coupled standing-wave interlaced-pulse dual-energy mode, are described. The design concept, basic structure, microwave-tuning method, and cold-test procedure are described as well. The measured dispersion curve, spectrum characteristics, ?-f relation of the power coupler, and axial field distribution of the accelerating gradient are provided.

Song, Ki Baek; Li, Yonggui; Lee, Sanghyun; Lee, Byeong-No; Park, Hyung Dal; Cha, Sung-Su; Lee, Byung Cheol

2013-07-01

206

Applying Data Mining Technique to Compute LDE for Rutting Through Full Scale Accelerated Pavement Testing  

Microsoft Academic Search

Results from closely controlled full-scale Accelerated Pavement Testing (APT) were employed to establish a rutting prediction model using the Find Laws data mining technique. Seven test pavements (264 records) from the Cold Regions Research and Engineering Laboratory's (CRREL's) Heavy Vehicle Simulator (HVS) and one test pavement including 8 records from the Texas Department of Transportation's (TxDOT's) Mobile Load Simulator (MLS)

Tung-Tsan Chen; Jia-Ruey Chang; Dar-Hao Chen

2008-01-01

207

Reliability of modified designs: a Bayes analysis of an accelerated test of electronic assemblies  

Microsoft Academic Search

Accelerated tests on two similar assemblies suggest that their lifetimes are in excess of 30000 h. A Bayes approach to reliability estimation using life test data from the two assemblies and those from an earlier evaluation of a third assembly, similar to the two under study, is described. The Bayes approach permitted a reduction in the number of test samples,

Louis Hart; Reader Aids

1990-01-01

208

Accelerated Desensitization and Adaptive Attitudes Interventions and Test Gains with Academic Probation Students  

ERIC Educational Resources Information Center

The study evaluates the test-gain benefits of an accelerated desensitization and adaptive attitudes intervention for test-anxious students. College students were screened for high test anxiety. Twenty anxious students, half of them on academic probation, were assigned to an Intervention or to a minimal treatment Control group. The Intervention was

Driscoll, Richard; Holt, Bruce; Hunter, Lori

2005-01-01

209

Accelerated life-tests for intermittent destructive inspection, with logistic failure-distribution  

Microsoft Academic Search

Statistically-optimal accelerated life-test plans are suggested for items whose lifetime follows a logistic distribution. Both the scale and location parameters of the lifetime distribution are functions of the stress level. The test plans accommodate intermittent destructive sampling. The number of sampled items which fail to pass the test at the time of each inspection follows a hypergeometric distribution; the number

So Young Sohn

1997-01-01

210

Acceleration of corrosion tests of the structural elements of passenger airplane fuselages  

Microsoft Academic Search

The basic method of objective determination of the corrosion behavior of the materials of structural elements and also of protective coatings under actual service conditions is field tests. Since such tests are laborious and not always possible, in practice wide use has been made of various methods of accelerated laboratory corrosion tests [1] from the results of which the corrosion

A. V. Karlashov; R. G. Gainutdinov; A. M. Svintsitskii; N. F. Voronkin; V. V. Sadkov; V. F. Voronov; E. A. Krasnov

1984-01-01

211

Status and Plans for an SRF Accelerator Test Facility at Fermilab  

SciTech Connect

A superconducting RF accelerator test facility is currently under construction at Fermilab. The accelerator will consist of an electron gun, 40 MeV injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, and multiple downstream beam lines for testing diagnostics and performing beam experiments. With 3 cryomodules installed this facility will initially be capable of generating an 810 MeV electron beam with ILC beam intensity. The facility can accommodate up to 6 cryomodules for a total beam energy of 1.5 GeV. This facility will be used to test SRF cryomodules under high intensity beam conditions, RF power equipment, instrumentation, and LLRF and controls systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

Church, M.; Leibfritz, J.; Nagaitsev, S.; /Fermilab

2011-07-29

212

Quality Control Testing of Cables for Accelerator Magnets.  

National Technical Information Service (NTIS)

A large number of cables have been tested for the CBA, HERA, and SSC Projects. The short sample test procedures and apparatus are reviewed. A simple rule for estimating cable performance from measurements on strands taken from the cable is described. By u...

M. Garber W. B. Sampson

1989-01-01

213

ACCELERATED TESTING METHODS FOR NEXT-GENERATION LAUNCH VEHICLES  

Microsoft Academic Search

Composite tanks are planned to be used for storage of propellants in future reusable space vehicles. The durability of these tanks is now determined by a predictive design methodology based on verification by extensive experimental testing under representative service conditions encountered by the tanks during their lifecycle. These tests include filling and pressurization of a tank while subjected to anticipated

Frank Abdi; D. Huang; Ross Messinger

2003-01-01

214

Low-energy demonstration accelerator (LEDA) test results and plans  

SciTech Connect

The LEDA 75-keV injector and 6.7-MeV RFQ have been tested with pulsed and cw proton beam currents up to 100 mA. Several LINAC2000 papers give the results of those measurements. A follow-on experiment, to intentionally introduce and measure beam halo on the RFQ output beam, is reported in several papers at this conference (PAC2001). In this paper we summarize the LEDA RFQ commissioning results and the beam-halo measurements and we discuss future test plans for this high-current, high-average-power rf structures test bed.

Smith, H. V. (Horace V.); Schneider, J. D. (J. David); Sheffield, R. L. (Richard L.)

2001-01-01

215

High brightness photocathode injector for BNL Accelerator Test Facility  

SciTech Connect

An analysis of the BNL photocathode (1-1/2 cell) Gun'' operating at 2856 MHZ, is presented. The beam parameters including beam energy, and emittance are calculated. A review of the Gun parameters and full input and output of our analysis with program PARMELA, is given in Section 2, some of our results, are tabulated. The phase plots and the beam parameters, at downstream ends of the elements, from cathode through the cavity, first cell is labeled as element 2; and second cell is labeled as element to the exit of the GUN. The analysis was made for 3 cases, using three different initial values (EO) for the average accelerating gradient (MV/m), for comparison with previous works. For illustration, the field obtained with program SUPERFISH is given, and conclusion including shunt impedances obtained for the cells and the cavity are given in Section 6. PARMELA is used as a standard design program at ATF. At the request of some of the users of program PARMELA, this request of some of the users of program PARMELA, this report include and illustrates some of our data, in the input and output format of the program PARMELA. 5 refs., 7 figs., 3 tabs.

Parsa, Z.; Young, L.

1990-01-01

216

Optimum Simple StepStress Plans for Accelerated Life Testing  

Microsoft Academic Search

This paper presents optimum plans for simple (two stresses) step-stress tests where all units are run to failure. Such plans minimize the asymptotic variance of the maximum likelihood estimator (MLE) of the mean life at a design stress. The life-test model consists of: 1) an exponential life distribution with 2) a mean that is a log-linear function of stress, and

Robert Miller; Wayne Nelson

1983-01-01

217

Accelerated in vitro release testing methods for extended release parenteral dosage forms  

PubMed Central

Objectives This review highlights current methods and strategies for accelerated in vitro drug release testing of extended release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in situ depot-forming systems, and implants. Key findings Extended release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, real-time in vitro release tests for these dosage forms are often run over a long time period. Accelerated in vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in vitro release methods using United States Pharmacopoeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended release parenteral dosage forms, along with the accelerated in vitro release testing methods currently employed are discussed. Conclusions Accelerated in vitro release testing methods with good discriminatory ability are critical for quality control of extended release parenteral products. Methods that can be used in the development of in vitro-in vivo correlation (IVIVC) are desirable, however for complex parenteral products this may not always be achievable.

Shen, Jie; Burgess, Diane J.

2012-01-01

218

Preliminary results from pressure tank test and field acceleration test of New-Profiling float of Japan (NINJA)  

Microsoft Academic Search

As one of contributions of Japan to the international Argo community, one of Japanese ocean instrument manufacturers, Tsurumi Seiki Co. (TSK), has started the development of original profiling float in 2000. We purchased the four TSK floats in 2001, and performed the pressure tank test and the acceleration field test in the north Pacific. Among four floats, two are carrying

K. Izawa; K. Ando; K. Mizuno; A. Inoue; N. Shikama; K. Takeuchi; M. Sekimoto

2002-01-01

219

A NOVEL METHODOLOGY OF INTERNAL NOTCHED PIPE TESTING AS AN ACCELERATED TEST FOR PLASTIC PIPING MATERIALS IN POTABLE WATER APPLICATIONS  

Microsoft Academic Search

Accelerated testing at elevated temperatures and multiple hoop stresses has been the basis for various test methodologies to ensure the performance of plastic piping materials in potable water applications. The most common practice is to use the Rate Process Method (RPM) and extrapolate the failure times to end use conditions. In this paper, a new method is explored that examines

Sarah Chung; Tieqi Li; Ken Oliphant; Patrick Vibien

220

Design and Factory Test of the E /E- Frascati Linear Accelerator for DAFNE  

SciTech Connect

The electron-positron accelerator for the DAFNE project has been built and is in test at Titan Beta in Dublin, CA. This S-Band RF linac system utilizes four 45 MW sledded klystrons and 16-3 m accelerating structures to achieve the required performance. It delivers a 4 ampere electron beam to the positron converter and accelerates the resulting positrons to 550 MeV. The converter design uses a 4.3T pulsed tapered flux compressor along with a pseudo-adiabatic tapered field to a 5 KG solenoid over the first two positron accelerating sections. Quadrupole focusing is used after 100 MeV. The system performance is given in Table 1. This paper briefly describes the design and development of the various subassemblies in this system and gives the initial factory test data.

Anamkath, H.; Lyons, S.; Nett, D.; Treas, P.; Whitham, K.; Zante, T.; /Titan Beta, Dublin; Miller, R.; /Titan Beta, Dublin /SLAC; Boni, R.; Hsieh, H.; Sannibale, F.; Vescovi, M.; Vignola, G.; /Frascati

2011-11-28

221

Commissioning of the first drift tube linac module in the Ground Test Accelerator  

Microsoft Academic Search

The Ground Test Accelerator (GTA) has the objective of verifying much of the technology required for producing high-brightness, high-current H- beams. GTA commissioning is staged to verify the beam-dynamics design of each major accelerator component as it is brought online. The major components are the 35-keV H- injector, the 2.5-MeV radiofrequency quadrupole (RFQ), the intertank matching section (IMS), the 3.2

K. F. Johnson; O. R. Sander; G. O. Bolme; S. Bowling; R. Connolly; P. Denney; J. Erickson; J. D. Gilpatrick; W. B. Ingalls; D. Kersteins; R. Kraus; W. P. Lysenko; D. McMurry; C. T. Mottershead; J. Power; C. Rose; D. P. Rusthoi; D. P. Sandoval; J. D. Schneider; M. Smith; G. Vaughn; E. A. Wadlinger; R. Weiss; V. Yuan

1993-01-01

222

Technological Issues and High Gradient Test Results on X-Band Molybdenum Accelerating Structures  

SciTech Connect

Two 11.424 GHz single cell standing wave accelerating structures have been fabricated for high gradient RF breakdown studies. Both are brazed structures: one made from copper and the other from sintered molybdenum bulk. The tests results are presented and compared to those of similar devices constructed at SLAC (Stanford Linear Accelerator Center) and KEK (Ko Enerugi Kasokuki Kenkyu Kiko). The technological issues to build both sections are discussed.

Spataro, B.; /LNF, Dafne Light; Alesini, D.; /LNF, Dafne Light; Chimenti, V.; /LNF, Dafne Light; Dolgashev, V.; /SLAC; Haase, A.; /SLAC; Tantawi, S.G.; /SLAC; Higashi, Y.; /KEK, Tsukuba; Marrelli, C.; /Rome U.; Mostacci, A.; /Rome U.; Parodi, R.; /INFN, Genoa; Yeremian, A.D.; /SLAC

2012-04-24

223

Electro-Optic Sampling at the TESLA Test Accelerator: Experimental Setup and First Results  

Microsoft Academic Search

Abstract A mode-locked titanium-sapphire laser with 15 fs pulse width is used to determine the temporal profile of the ultrashort electron bunches in the linear TESLA Test accelerator. The experimental setup is described and first results are presented on the synchronization of the Ti:Sa laser with the radio frequency of the superconducting accelerator and on the coincidence measurements between the

M. Brunken; H. Genz; P. Gottlicher; C. Hessler; M. Huning; H. Loos; A. Richter; H. Schlarb; P. Schmuser; S. Simrock; D. Suetterlin; M. Tonutti; D. Turke; Physikalisches Insitut Iiia; Rwth Aachen

224

BUNCH-LENGTH MEASUREMENTS AT SCSS TEST ACCELERATOR TOWARD XFEL\\/SPRING8  

Microsoft Academic Search

The SCSS test accelerator, which was constructed to check the feasibility of XFEL\\/SPring-8, is being operated for user experiments using stable EUV (Extreme Ultra- violet) SASE. This accelerator provides a high-quality electron beam with parameters, such as a bunch length of 300 fs and a peak current of 700 A, for power saturation of the EUV SASE. Evaluating the parameters

Y. Otake; S. Matsubara; H. Maesaka; K. Tamasaku; T. Togashi; K. Togawa; H. Tanaka; Sayo-cho Kouto; Hamamatsu Photonics

225

Accelerated performance testing of concrete pavement with short slabs  

Microsoft Academic Search

A new concept for designing concrete pavements by optimising the slab geometry in order to reduce the slab thickness as well as to minimise the mechanical load transfer devices has recently been proposed. Theoretically, the reduced slab size lowers the load and curling-induced tensile stresses and concomitantly a thinner concrete slab can be constructed. Full-scale test sections were constructed and

Jeffery R. Roesler; Victor G. Cervantes; Armen N. Amirkhanian

2011-01-01

226

Corrosion-inhibiting gas-turbine engine lubricant. I. Accelerated test development and validation  

Microsoft Academic Search

A program was undertaken to develop an accelerated test procedure for evaluating the relative corrosion protection provided by candidate corrosion-inhibited gas-turbine engine lubricants. Several test parameters were investigated, including various humidifying solutions, air flow rates, residence times, and test coupon surface preparations, which resulted in the development of a one-hour vapor-phase corrosion test, the Corrosion Rate Evaluation Procedure (CREP). The

P. A. Warner; W. J. Purvis

1984-01-01

227

Accelerated drop test simulation using relative coordinate solution and finite element method  

Microsoft Academic Search

Shock resistance of hard disk drives (HDDs) tends to be a critical issue with the rapid growth of portable consumer electronics such as notebooks, PDAs, and digital cameras. Finite element method (FEM) is widely used in simulating drop test. However, it is computationally expensive. An accelerated drop test method, which adopts relative coordinate and recursive solutions, is developed. The computational

Jisong Sun; Youcheng Li; Eng Hong Ong

2004-01-01

228

Analysis of Accelerated Life Test Data - Part I: The Arrhenius Model and Graphical Methods  

Microsoft Academic Search

This is Part I of a three-part series presenting statistical methods for planning and analyzing temperature-accelerated life tests when all test units are run to failure. These methods are presented so they can be profitably used by individuals with a limited statistical background. In Part I, the Arrhenius model is described, and graphical methods for analysis of such complete data

Wayne Nelson

1971-01-01

229

Solution for the Board Level Drop Test in Vertical Direction of BGA Package under Ultrahigh Acceleration  

Microsoft Academic Search

With the population of portable device growing, mechanical drop reliability of BGA soldering becomes more and more important. Drop test for the BGA-PCB assemblies can be performed in both horizontal and vertical directions. Unfortunately, soldering in vertical drop test will generally fail only under such an ultrahigh acceleration that is too high to be achieved by the conventional drop tester.

Zhaoyi Chen; Bo Qi; Jiaji Wang; Taekoo Lee

2006-01-01

230

A Scalability Test for Accelerated DE Using Generalized Opposition-Based Learning  

Microsoft Academic Search

In this paper a scalability test over eleven scalable benchmark functions, provided by the current workshop (Evolutionary Algorithms and other Metaheuristics for Continuous Optimization Problems-A Scalability Test), are conducted for accelerated DE using generalized opposition-based learning (GODE). The average error of the best individual in the population has been reported for dimensions 50, 100, 200, and 500 in order to

Hui Wang; Zhijian Wu; Shahryar Rahnamayan; Lishan Kang

2009-01-01

231

DESIGN OF FAILURE-CENSORED ACCELERATED LIFE-TEST SAMPLING PLANS FOR LOGNORMAL AND WEIBULL DISTRIBUTIONS  

Microsoft Academic Search

This paper considers the design of life-test sampling plans based on failure-censored accelerated life tests for products with lognormal and Weibull lifetime distributions. Two levels of stress higher than the use condition stress, high and low, are used. The sample size, sample proportion allocated to each stress level, and the lot acceptability constant which satisfy the producer's risk and consumer's

D. S. BAI; J. G. KIM; Y. R. CHUN

1993-01-01

232

Accelerated laboratory corrosion test for materials and finishes used in naval aircraft. Progress report  

Microsoft Academic Search

An accelerated laboratory corrosion test has been developed to screen materials and finishes for use on naval aircraft. Sulfur dioxide is introduced at periodic intervals into a conventional salt fog chamber to simulate conditions produced by the carrier stack gas\\/marine environment. Procedures for conducting the test are described.

Ketcham

1977-01-01

233

Optimal StepStress Accelerated Degradation Test Plan for Gamma Degradation Processes  

Microsoft Academic Search

Step-stress accelerated degradation testing (SSADT) is a useful tool for assessing the lifetime distribution of highly reliable products (under a typical-use condition) when the available test items are very few. Recently, an optimal SSADT plan was proposed based on the assumption that the underlying degradation path follows a Wiener process. However, the degradation model of many materials (especially in the

Sheng-Tsaing Tseng; Narayanaswamy Balakrishnan; Chih-Chun Tsai

2009-01-01

234

A facility to test short superconducting accelerator magnets at Fermilab  

SciTech Connect

During the past four years the Superconducting Magnet R D facility at Fermilab (Lab 2) has successfully tested superconducting dipole, quadrupole, and correction coil magnets less than 2 meters in length for the SSC project and the Tevatron D0/B0 Low-[beta] Insertion. During this time several improvements have been made to the facility that have greatly enhanced its magnet testing capabilities. Among the upgrades have been a new rotating coil and data acquisition system for measuring magnetic fields, a controlled flow liquid helium transfer line using an electronically actuated cryo valve, and stand-alone systems for measuring AC loss and training low current Tevatron correction coil packages. A description of the Lab 2 facilities is presented.

Lamm, M.J.; Hess, C.; Lewis, D.; Jaffery, T.; Kinney, W.; Ozelis, J.P.; Strait, J. (Fermi National Accelerator Lab., Batavia, IL (United States)); Butteris, J.; McInturff, A.D. (Superconducting Super Collider Lab., Dallas, TX (United States)); Coulter, K.J. (Argonne National Lab., IL (United States))

1992-10-01

235

A facility to test short superconducting accelerator magnets at Fermilab  

SciTech Connect

During the past four years the Superconducting Magnet R&D facility at Fermilab (Lab 2) has successfully tested superconducting dipole, quadrupole, and correction coil magnets less than 2 meters in length for the SSC project and the Tevatron D0/B0 Low-{beta} Insertion. During this time several improvements have been made to the facility that have greatly enhanced its magnet testing capabilities. Among the upgrades have been a new rotating coil and data acquisition system for measuring magnetic fields, a controlled flow liquid helium transfer line using an electronically actuated cryo valve, and stand-alone systems for measuring AC loss and training low current Tevatron correction coil packages. A description of the Lab 2 facilities is presented.

Lamm, M.J.; Hess, C.; Lewis, D.; Jaffery, T.; Kinney, W.; Ozelis, J.P.; Strait, J. [Fermi National Accelerator Lab., Batavia, IL (United States); Butteris, J.; McInturff, A.D. [Superconducting Super Collider Lab., Dallas, TX (United States); Coulter, K.J. [Argonne National Lab., IL (United States)

1992-10-01

236

An accelerated exposure and testing apparatus for building joint sealants  

NASA Astrophysics Data System (ADS)

The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

White, C. C.; Hunston, D. L.; Tan, K. T.; Hettenhouser, J.; Garver, J. D.

2013-09-01

237

An accelerated exposure and testing apparatus for building joint sealants.  

PubMed

The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants. PMID:24089872

White, C C; Hunston, D L; Tan, K T; Hettenhouser, J; Garver, J D

2013-09-01

238

Field Operations Program Chevrolet S-10 (Lead-Acid) Accelerated Reliability Testing - Final Report  

SciTech Connect

This report summarizes the Accelerated Reliability testing of five lead-acid battery-equipped Chevrolet S-10 electric vehicles by the US Department of Energy's Field Operations Program and the Program's testing partners, Electric Transportation Applications (ETA) and Southern California Edison (SCE). ETA and SCE operated the S-10s with the goal of placing 25,000 miles on each vehicle within 1 year, providing an accelerated life-cycle analysis. The testing was performed according to established and published test procedures. The S-10s' average ranges were highest during summer months; changes in ambient temperature from night to day and from season-to-season impacted range by as much as 10 miles. Drivers also noted that excessive use of power during acceleration also had a dramatic effect on vehicle range. The spirited performance of the S-10s created a great temptation to inexperienced electric vehicle drivers to ''have a good time'' and to fully utilize the S-10's acceleration capability. The price of injudicious use of power is greatly reduced range and a long-term reduction in battery life. The range using full-power accelerations followed by rapid deceleration in city driving has been 20 miles or less.

J. Francfort (INEEL); J. Argueta; M. Wehrey (Southern California Edison); D. Karner; L. Tyree (Electric Transportation Applications)

1999-07-01

239

Use of the LEDA Facility as an ADS High-Power Accelerator Test Bed  

SciTech Connect

The Low-Energy Demonstration Accelerator (LEDA) was built to generate high-current proton beams. Its successful full-power operation and testing in 1999-2001 confirmed the feasibility of a high-power linear accelerator (linac) front end, the most technically challenging portion of such a machine. The 6.7-MeV accelerator operates reliably at 95-mA CW beam current with few interruptions orjaults, and qualiJes as one of the most powerful accelerators in the world. LEDA is now available to address the needs of other programs. LEDA can be upgraded in a staged fashion to allow for full-power accelerator demonstrations. The proposed post-h!FQ accelerator structures are 350-MHz superconducting spoke cavities developed for the AAA /APT program. The superconducting portion of the accelerator is designed for a IOO-mA proton beam current. Superconducting cavities were chosen because of the signijkant thermal issues with room-temperature structures, the larger superconducting cavity apertures, and the lower operating costs ('because of improved electrical efficiency) of a superconducting accelerator. Since high reliability is a major issue for an ADS system, the superconducting design architecture alIows operation through faults due to the failure of single magnets or superconducting cavities. The presently installed power capacity of 13 MVA of input ACpower is capable of supporting a 40-MeVproton beam at 100 mA. (The input power is easily expandable to 25 MVA, allowing up to 100-MeV operation). Operation at 40-MeV would provide a complete demonstration of all of the critical accelerator sub-systems ofa full-power ADS system.

Garnett, R. W. (Robert W.); Sheffield, R. L. (Richard L.)

2003-01-01

240

UV-accelerated test based on analysis of field-exposed PV modules  

NASA Astrophysics Data System (ADS)

We proposed an UV accelerated test condition for an EVA encapsulant, based on analysis of long term field exposed PV modules. We found that strong UV irradiation into EVA encapsulant test sample led to the fast decomposition of UV absorber formulated in EVA encapsulant, which has never seen in the field exposed PV modules. Thus, the integrating UV intensity of 60 W/m2 and black panel temperature of 110C using a xenon weather-o-meter were suitable as an UV accelerated test condition. With this proposed test condition, which shows that 1 week exposure by xenon light corresponds to 1 year field exposure, we can predict discoloration rate of EVA encapsulant. In addition, we evaluated change in peel strength to glass for Mitsui's and the other commercially available EVA encapsulants during UV accelerated test with the proposed condition. There was no large change in peel strength for our EVA encapsulant during the UV accelerated test. On the other hand, we observed that the competitor's EVA encapsulant showed the large decrease of peel strength to glass at early stage, even no change in yellowness index (YI). This result indicates not only YI change but also peel strength change should be evaluated for design of reliable PV module and encapsulant.

Shioda, T.

2011-09-01

241

Construction and testing of an 11.4 GHz dielectric structure based travelling wave accelerator.  

SciTech Connect

One major challenge in constructing a dielectric loaded traveling wave accelerator powered by an external rf power source is the difficulty in achieving efficient coupling. In this paper, we report that we have achieved high efficiency broadband coupling by using a combination of a tapered dielectric section and a carefully adjusted coupling slot. We are currently constructing an 11.4 GHz accelerator structure loaded with a permitivity=20 dielectric. Bench testing has demonstrated a coupling efficiency in excess of 95% with bandwidth of 600 MHz. The final setup will be tested at high power at SLAC using an X-band klystron rf source.

Gai, W.; Konecny, R.; Wong, T.; Zou, P.

1999-03-26

242

Production and test results of SC 3.9-GHz accelerating cavity at Fermilab  

SciTech Connect

The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve beam performances for TTF-FEL facility. In the frame of collaboration Fermilab will provide DESY with a cryomodule containing a string of four cavities. In addition, a second cryomodule with one cavity will be fabricated for installation in the Fermilab photo-injector, which will be upgraded for the ILC accelerator test facility. In this paper we discuss the status of the cavity and coupler production and the first result of cavity tests. It is hoped that this project will be completed during the first half of 2007 and the cryomodule delivered to DESY in this time span.

Khabiboulline, Timergali; Cooper, Charlie; Edwards, Helen; Foley, Mike; Gonin, Ivan; Mitchell, Donald; Olis, D.; Rowe, Allan; Salman, Tariq; Solyak, Nikolay; /Fermilab

2006-08-01

243

Vertical and horizontal test results of 3.9-GHz accelerating cavities at FNAL  

SciTech Connect

The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve the beam performance of the VUV FEL, FLASH. In the frame of a collaborative agreement, Fermilab will provide DESY with a cryomodule containing a string of four cavities. Seven 9-cell Nb cavities were tested and six of them did reach accelerating gradient up to 24 MV/m almost twice more than design value of 14 MV/m. Two of these cavities are with new HOM couplers with improved design. In this paper we present all results of the vertical and horizontal tests.

Khabiboulline, T.; Edwards, H.; Foley, M.; Harms, E.; Hocker, James Andrew; Mitchell, D.; Rowe, A.; Solyak, N.; /Fermilab

2008-06-01

244

Testing of vacuum pumps for the Accelerator Production of Tritium/Low Energy Demonstration Accelerator radio frequency quadrupole  

SciTech Connect

Two vacuum systems were designed and built for the RFQ (Radio Frequency Quadrupole) cavity in the APT/LEDA (Low Energy Demonstration Accelerator) linac. The gas load from the proton beam required very high hydrogen pump speed and capacity. The gas load from the high power RF windows also required very high hydrogen pump speed for the RF window vacuum system. Cryopumps were chosen for the RFQ vacuum system and ST185 sintered non-evaporable getter (NEG) cartridges were chosen for the RF window vacuum system. Hydrogen pump speed and capacity measurements were carried out for a commercial cryopump and a NEG pump. This paper will discuss the test procedures and the results of the measurements.

Kishiyama, K.; Shen, S.; Behne, D. [Lawrence Livermore National Lab., CA (United States); Wilson, N.G. [AMPARO Inc., Los Alamos, NM (United States); Schrage, D.; Valdiviez, R. [Los Alamos National Lab., NM (United States)

1998-12-31

245

High power testing oa ANL X-band dielectric-loaded accelerating structures.  

SciTech Connect

In the second phase of a program to develop a compact accelerator based on a dielectric-loaded accelerating structure, we have conducted high power tests on a traveling-wave and a standing-wave prototype. Indications are that the traveling-wave structure achieved an accelerating gradient of 3-5 MV/m before the input coupling window failed, while the standing wave structure was poorly matched at high power due to contamination of copper residue on its coupling window. To solve both of these problems, a new method for coupling RF into the structures has been developed. The new couplers and the rest of the modular structure are currently under construction and will be tested at the Naval Research Laboratory shortly.

Power, J. G.; Gai, W.; Jing, C.; Konecny, R.; Gold, S. H.; Kinkead, A. K.

2002-09-12

246

Design and test results of the Low Energy Demonstration Accelerator (LEDA) RF systems  

SciTech Connect

The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos will serve as the prototype for the low energy section of the Accelerator Production of Tritium (APT) accelerator. The APT accelerator requires over 200 RF systems each with a continuous wave output power of 1 MW. The reliability and availability of these RF systems is critical to the successful operation of the APT plant and prototypes of these systems are being developed and demonstrated on LEDA. The RF system design for LEDA includes three, 1.2 MW, 350 MHz continuous wave (CW), RF systems driving a radio frequency quadrupole (RFQ) and one, 1.0 MW, CW, RF system driving a coupled-cavity drift tube linac (CCDTL). This paper presents the design and test results for these RF systems including the klystrons, cathode power supply, circulators, RF vacuum windows, accelerator field and resonance control system, and RF transmission components. The three RF systems driving the RFQ use the accelerating structure as a power combiner, and this places some unique requirements on the RF system. These requirements and corresponding operational implications will be discussed.

Rees, D.; Bradley, J. III; Cummings, K.; Lynch, M.; Regan, A.; Rohlev, T.; Roybal, W.; Wang, Y.M.

1998-12-01

247

Design of the in-situ testing system for the accelerated life test of the space infrared device  

NASA Astrophysics Data System (ADS)

Space infrared detector is the core component of photoelectric conversion in the infrared system, the indicator of which, such as sensibility and reliability, limits the optimum performance of the detection system. In the reliability research of infrared detector, the operating life of the device is a very important index and also a significant subject in the engineering application. In the accelerated life test of space infrared detector, it was difficult to periodically measure blackbody response signal of infrared detector, due to equipment limitations for a long time. Accordingly, it was also hard to get abundant failure data of devices for statistical analysis. For this problem, we designed a novel multi-station testing system for accelerated life test of space infrared device, in which response signal as well as temperature can be measured in-situ and recorded for further analysis. Based on theoretical calculation and analysis of actual measured data, we studied and designed the mechanical structure of the equipment and the key component of the testing system, such as the displacement platform, illustrated the control algorithm and put up a system design proposal which meet the testing requirements well. This work technically supports the accelerated life test of space infrared device.

Zhu, Xianliang; Zhang, Haiyan; Wang, Yang; He, Xiangrong; Gong, Haimei

2013-09-01

248

Semi-empirical formula for spontaneous fission half life time  

NASA Astrophysics Data System (ADS)

A new semi-empirical formula is proposed for determining the spontaneous fission half lives, which works well for the mass region from 232Th to 286114. The computed spontaneous fission half life times are also compared with other semi-empirical formula predictions. The alpha decay half lives are systematically computed for heavy and super heavy region with proton numbers varying from 90?Z?122 using Coulomb and Proximity Potential Model. The comparison between computed alpha decay half lives and the present spontaneous fission semi-empirical formula predictions of even-even isotopes with Z=90-122 are studied. It is found that in super heavy region the isotopes 270-274Ds, 272-278112, 272-282114, 274-292116, 276-298118, 276-308120 and 278-314122 will survive fission and can be synthesized and identified via alpha decay.

Santhosh, K. P.; Biju, R. K.; Sahadevan, Sabina

2010-01-01

249

600 kV modulator design for the SLAC Next Linear Collider Test Accelerator.  

National Technical Information Service (NTIS)

Preliminary design for the SLAC Next Linear Collider Test Accelerator (NLCTA) requires a pulse power source to produce a 600 kV, 600 A, 1.4 (mu)s, 0.1% flat top pulse with rise and fall times of approximately 100 ns to power an X-Band klystron with a micr...

K. Harris J. de Lamare V. Nesterov R. Cassel

1992-01-01

250

Accelerator testing of the general antiparticle spectrometer; a novel approach to indirect dark matter detection  

Microsoft Academic Search

We report on recent accelerator testing of a prototype general antiparticle spectrometer (GAPS). GAPS uses a novel approach for indirect dark matter searches that exploits the antideuterons produced in neutralino neutralino annihilations. GAPS captures these antideuterons into a target with the subsequent formation of exotic atoms. These exotic atoms decay with the emission of x-rays of precisely defined energy and

C. J. Hailey; T. Aramaki; W. W. Craig; L. Fabris; F. Gahbauer; J. E. Koglin; N. Madden; K. Mori; H. T. Yu; K. P. Ziock

2006-01-01

251

An investigation of aging characteristics of polymer housed distribution surge arresters by accelerated aging test  

Microsoft Academic Search

The purpose of this paper is to verify the aging characteristics of domestic polymer housed distribution surge arresters. In this study accelerated aging test equipment was developed to simulate field condition of the distribution polymer housed surge arresters. Polymeric housing of distribution surge arresters should be degraded by environmental stress and the interface between housing and inner module can be

Juyong Kim; Yeunha Jung; Ilkeun Song

2008-01-01

252

Accelerated testing of Shaft Seals as components with complex failure modes  

Microsoft Academic Search

Radial Shaft Seals (RSS) are widely used in all fields of mechanical engineering for sealing of rotating elements. Up to now there has been no possibility to include Radial Shaft Seals adequately into the lifetime calculation of mechanical systems. In this paper the difficulties in accelerated life testing of RSS are presented and discussed. First of all, this involves the

Benjamin Klein; D. Kirschmann; W. Haas; B. Bertsche

2010-01-01

253

Impact of Water on the Response and Performance of a Pavement Structure in an Accelerated Test  

Microsoft Academic Search

An accelerated load test using a Heavy Vehicle Simulator (HVS) was performed with the objective of investigating the response behaviour and performance of a commonly used pavement structure in Sweden. The structure consists of 10 cm asphalt bound layers, divided into surface course and bitumen base, over granular base and subbase resting on sandy subgrade. The structure was instrumented to

Sigurdur Erlingsson

2010-01-01

254

Pulsed power checkout and initial testing of the rits-6 accelerator  

Microsoft Academic Search

Summary form only given. Upgrades to the Radiographic Integrated Test Stand (RITS-6) have been completed. Changes from the RITS-3 architecture include tripling the Marx bank capacitance and doubling the number of intermediate storage capacitors, pulse forming lines (PFL), and inductive voltage adder (FVA) cavities. The accelerator is capable of greater than 10 MV output voltage at 125 kA into an

J. J. Leckbee; S. Cordova; M. Johnston; J. Maenchen; I. Molina; B. Oliver; D. Rovang; D. L. Johnson

2006-01-01

255

Computational design of accelerated life testing applied to frozen green beans  

Microsoft Academic Search

Three different accelerated life tests (ALT) were designed by computer simulation to investigate their practical applicability to quantify kinetics of quality loss in frozen stored foods. Heat transfer and quality degradation inside a green bean were simulated, using a spectral finite element method (SFEM), to develop pseudo-experimental data. Temperature fluctuations inside a refrigerator were simulated, by a piecewise linear stochastic

R. C Martins; C. L. M Silva

2004-01-01

256

Test facility for investigation of heating of 30 GHz accelerating structure imitator for the CLIC project  

Microsoft Academic Search

Since 2001 an experimental test facility for investigation of lifetime of a copper material, with respect to multiple RF pulse actions, was set up on the basis of the JINR (Dubna) FEM oscillator, in collaboration with IAP RAS (Nizhny Novgorod). A high-Q copper cavity, which simulates the parameters of the accelerating structure of the collider CLIC at an operating frequency

A. V. Elzhov; N. S Ginzburg; A. K Kaminsky; S. V. Kuzikov; E. A Perelstein; N. Yu Peskov; M. I. Petelin; S. N Sedykh; A. P Sergeev; A. S Sergeev; I. Syratchev; N. I. Zaitsev

2004-01-01

257

Accelerated test methods to determine the long-term behavior of FRP composite structures: environmental effects  

Microsoft Academic Search

Technical literature on the subject of environmental exposure effects related to determining accelerated test methods for the prediction of long-term performance of FRP composite materials for highway structural applications is reviewed in this paper. Effects of environmental exposure of a chemical and a thermal nature on fiber-reinforced polymer (FRP) composites are considered. Such exposures include temperature, moisture and chemicals in

L. C. Bank; T. R. Gentry; A. Barkatt

1995-01-01

258

SUPER-FMIT, an accelerator based neutron source for fusion components irradiation testing  

NASA Astrophysics Data System (ADS)

The SUPER-FMIT facility is proposed as an advanced accelerator based neutron source for high flux irradiation testing of large-sized fusion reactor components. The facility would require only small extensions to existing accelerator and target technology originally developed for the Fusion Materials Irradiation Test (FMIT) facility. There, neutrons would be produced by a 0.1 A beam of 35 MeV deuterons incident upon a liquid lithium target. The volume available for high flux (> 1014n/cm2s) testing in SUPER-FMIT would be 14 1, about a factor of 30 larger than in the FMIT facility. This is because the effective beam current of 35 MeV deuterons on target can be increased by a factor of ten to 1.0 A or more. Such a large increase can be accomplished by acceleration of multiple beams of molecular deuterium ions (D+2) to 70 MeV in a common accelerator structure. The availability of multiple beams and large total current allows great variety in the testing that can be done. For example, fluxes greater than 1016 n/cm2 s, multiple simultaneous experiments and great flexibility in tailoring of spatial distributions of flux and spectra can be achieved.

Burke, R. J.; Holmes, J. J.; Johnson, D. L.; Mann, F. M.; Miles, R. R.

1985-05-01

259

Accelerated Development of Corrosion Inhibitor Formulations by Electrochemical Methods and Short-Time Corrosion Tests  

Microsoft Academic Search

A combined general approach to the development of corrosion inhibitors for industrial applications based on electrochemical measurements along with both standard and accelerated corrosion tests has been developed. Electrochemical measurements (corrosion potential, cyclic voltammetry and polarization resistance) are used to assess both relevant physical properties and the relative corrosion protection efficiencies of new inhibitor formulations. Additionally, electrochemical techniques provide quick

Hochschule Zittau

260

Design of PH-based accelerated life testing plans under multiple-stress-type  

Microsoft Academic Search

Accelerated life testing (ALT) is used to obtain failure time data quickly under high stress levels in order to predict product life performance under design stress conditions. Most of the previous work on designing ALT plans is focused on the application of a single stress. However, as components or products become more reliable due to technological advances, it becomes more

E. A. Elsayed; Hao Zhang

2007-01-01

261

A statistical treatment of accelerated life test data for copper-water heat pipes  

Microsoft Academic Search

A statistical method is proposed to treat accelerated life test data conducted at several elevated temperatures for a sufficient number of commercially available Cu-water heat pipes to predict the operation life. The temperature distribution measurements periodically carried out yield both data sets concerning the temperature drop and the gas column length as measures of noncondensible gas accumulation. The gas analysis

M. Murakami; K. Arai; Y. Kojima

1988-01-01

262

Development of a service-simulating, accelerated aging test method for exterior tire rubber compounds II. Design and development of an accelerated outdoor aging simulator  

Microsoft Academic Search

During storage and service, exterior tire rubber compounds are subject to aging due to multiple factors. This process cannot be accurately represented by conventional single factor tests. The overall goal of our research is to develop an accelerated, service-simulating, artificial aging test for exterior rubber compounds. During the first part of this work, a cyclic test consisting of a series

Bart J. LaCount; Jose M. Castro; Frederick Ignatz-Hoover

2002-01-01

263

Effects of accelerated testing on porcine bioprosthetic heart valve fiber architecture  

Microsoft Academic Search

We undertook the following study to quantitatively assess the changes in porcine bioprosthetic heart valve (PBHV) fiber architecture to increasing levels of fatigue damage using an in vitro accelerated test model. PBHVs were subjected to 0500 million test cycles at 16Hz, and small-angle light scattering (SALS) was used to quantify the gross fiber structure of the cusps. The degree of

Michael S. Sacks; David B. Smith

1998-01-01

264

The first picosecond terawatt CO{sub 2} laser at the Brookhaven Accelerator Test Facility  

SciTech Connect

The first terawatt picosecond CO{sub 2} laser will be brought to operation at the Brookhaven Accelerator Test Facility in 1998. System consists of a single-mode TEA oscillator, picosecond semiconductor optical switch, multi-atmosphere. The authors report on design, simulation, and performance tests of the 10 atm final amplifier that allows for direct multi-joule energy extraction in a picosecond laser pulse.

Pogorelsky, I.V.; Ben-Zvi, I.; Babzien, M. [and others

1998-02-01

265

EPIDEMIOLOGICAL STUDY ON SN-AG-CU SOLDER: BENCHMARKING RESULTS FROM ACCELERATED LIFE TESTING  

Microsoft Academic Search

This paper will present the results of a comprehensive overview of accelerated life testing (ALT) of components assembled with SnAgCu solder. Over 100 private documents and published articles were assessed for data on SnAgCu performance under temperature cycling. Data on test parameters, component materials and design, and interconnect dimensions were acquired and results were grouped by attach geometry, including leadless

Craig Hillman; Nathan Blattau; Ed Dodd; Joelle Arnold

266

Models of f(R) cosmic acceleration that evade solar system tests  

Microsoft Academic Search

We study a class of metric-variation f(R) models that accelerates the expansion without a cosmological constant and satisfies both cosmological and solar-system tests in the small-field limit of the parameter space. Solar-system tests alone place only weak bounds on these models, since the additional scalar degree of freedom is locked to the high-curvature general-relativistic prediction across more than 25 orders

Wayne Hu; Ignacy Sawicki

2007-01-01

267

Times to cracking in reinforced mortar beams subjected to accelerated corrosion tests  

Microsoft Academic Search

This paper is devoted to the description of the effects of corrosion on mechanical behaviour of reinforced mortar beams. Corrosion\\u000a tests have been performed through accelerated tests for two configurations of beams (rebar at the corner or in the middle).\\u000a Critical times related to the development of cracking have been defined by using strain measurements, potential drop and visual\\u000a observations.

S. Car; Q. T. Nguyen; K. Beddiar; Y. Berthaud

2010-01-01

268

Accelerator driven gamma and fast neutron radiography test-bed at Lawrence Livermore National Laboratory  

NASA Astrophysics Data System (ADS)

Accelerator driven fusion gammas and fast neutrons could provide unique radiography capabilities due to their ability to produce both high and low energy mono-energetic gammas and neutrons compared with broadband bremsstrahlung based x-ray sources. The possibility of simultaneously obtaining both gamma and neutron radiographs using one source could allow complex objects composed of a large range of low to high Z materials to be imaged. In this paper we review a 4 MV RFQ accelerator driven radiography test-bed at LLNL designed to study the physics involved in applying these dual output fusion reactions for radiography applications. First experimental neutron images from a carbon target are presented.

Tang, V.; Rusnak, B.; Falabella, S.; Hawkins, S.; McCarrick, J. F.; Wang, H.; Hall, J. M.; Ellsworth, J.

2013-04-01

269

Status and specifications of a Project X front-end accelerator test facility at Fermilab  

SciTech Connect

This paper describes the construction and operational status of an accelerator test facility for Project X. The purpose of this facility is for Project X component development activities that benefit from beam tests and any development activities that require 325 MHz or 650 MHz RF power. It presently includes an H- beam line, a 325 MHz superconducting cavity test facility, a 325 MHz (pulsed) RF power source, and a 650 MHz (CW) RF power source. The paper also discusses some specific Project X components that will be tested in the facility. Fermilab's future involves new facilities to advance the intensity frontier. In the early 2000's, the vision was a pulsed, superconducting, 8 GeV linac capable of injecting directly into the Fermilab Main Injector. Prototyping the front-end of such a machine started in 2005 under a program named the High Intensity Neutrino Source (HINS). While the HINS test facility was being constructed, the concept of a new, more versatile accelerator for the intensity frontier, now called Project X, was forming. This accelerator comprises a 3 GeV CW superconducting linac with an associated experimental program, followed by a pulsed 8 GeV superconducting linac to feed the Main Injector synchrotron. The CW Project X design is now the model for Fermilab's future intensity frontier program. Although CW operation is incompatible with the original HINS front-end design, the installation remains useful for development and testing many Project X components.

Steimel, J.; Webber, R.; Madrak, R.; Wildman, D.; Pasquinelli, R.; Evans-Peoples, E.; /Fermilab

2011-03-01

270

Radio-Frequency Power Test of a Four-Rod RFQ Accelerator for PKUNIFTY  

NASA Astrophysics Data System (ADS)

A four-rod radio frequency quadruple (RFQ) accelerator is designed, manufactured, installed and commissioned for the Peking University Neutron Imaging Facility (PKUNIFTY). This 2699.6-mm-long RFQ accelerator with the mean aperture radius of 3.88mm is operating at 201.5 MHz in pulse mode. An inter-electrode voltage of 70 kV is needed to accelerate the injected 50 keV 40 mA D+ ions up to 2 MeV. We present the rf system, high rf power feeder design, lower rf measurements and higher rf power test. Especially, the rf commissioning was carried out with rf power up to ~280 kW and duty factor of 4%. The measured x-ray spectrum shows that the rf inter-electrode voltage reaches 70.7 kV. It is found that the specific shunt impedance of the RFQ cavity reaches 52.7 k?m.

Zeng, Hong-Jin; Liu, Ge; Lu, Yuan-Rong; Chen, Wei; Zhou, Quan-Feng; Zhu, Kun; Xia, Wen-Long; Shi, Ben-Liang; Gao, Shu-Li; Yan, Xue-Qing; Guo, Zhi-Yu; Chen, Jia-Er

2012-06-01

271

OUTER GALACTIC DISKS AND A QUANTITATIVE TEST OF GRAVITY AT LOW ACCELERATIONS  

SciTech Connect

We use the recent measurement of the velocity dispersion of star-forming, outer-disk knots by Herbert-Fort et al. in the nearly face-on galaxy NGC 628, in combination with other data from the literature, to execute a straightforward test of gravity at low accelerations. Specifically, the rotation curve at large radius sets the degree of non-standard acceleration and then the predicted scale height of the knots at that radius provides the test of the scenario. For our demonstration, we presume that the H{alpha} knots, which are young (age < 10 Myr), are distributed like the gas from which they have recently formed and find a marginal (>97% confidence) discrepancy with a modified gravity scenario given the current data. More interestingly, we demonstrate that there is no inherent limitation that prevents such a test from reaching possible discrimination at the >4{sigma} level with a reasonable investment of observational resources.

Zaritsky, Dennis; Psaltis, Dimitrios, E-mail: dzaritsky@as.arizona.ed, E-mail: psaltis@as.arizona.ed [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

2010-09-01

272

New Accelerated Testing and Lifetime Modeling Methods Promise Faster Development of More Durable MEAs  

SciTech Connect

For the successful commercialization of fuel cell technology, it is imperative that membrane electrode assembly (MEA) durability is understood and quantified. MEA lifetimes of 40,000 hours remain a key target for stationary power applications. Since it is impractical to wait 40,000 hours for durability results, it is critical to learn as much information as possible in as short a time period as possible to determine if an MEA sample will survive past its lifetime target. Consequently, 3M has utilized accelerated testing and statistical lifetime modeling tools to develop a methodology for evaluating MEA lifetime. Construction and implementation of a multi-cell test stand have allowed for multiple accelerated tests and stronger statistical data for learning about durability.

Pierpont, D. M.; Hicks, M. T.; Turner, P. L.; Watschke, T. M.

2005-11-01

273

Advanced X-Band Test Accelerator for High Brightness Electron and Gamma Ray Beams  

SciTech Connect

In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

Marsh, Roark; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Chu, Tak Sum; /LLNL, Livermore; Ebbers, Chris; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

2012-07-03

274

ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS  

SciTech Connect

In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J; Hartemann, F V; Adolphsen, C; Jongewaard, E N; Raubenheimer, T; Tantawi, S G; Vlieks, A E; Wang, J W

2010-05-12

275

Corrosion-inhibiting gas-turbine engine lubricant. I. Accelerated test development and validation  

SciTech Connect

A program was undertaken to develop an accelerated test procedure for evaluating the relative corrosion protection provided by candidate corrosion-inhibited gas-turbine engine lubricants. Several test parameters were investigated, including various humidifying solutions, air flow rates, residence times, and test coupon surface preparations, which resulted in the development of a one-hour vapor-phase corrosion test, the Corrosion Rate Evaluation Procedure (CREP). The CREP was validated through general correlations with test results from the humidity cabinet corrosion test described in MIL-C-8188C. A sequential sampling plan, based on a statistical evaluation of CREP data, provided an efficient means for screening candidate corrosion-inhibiting fluids. The development and validation of the CREP and the sequential sampling plan are discussed in this paper.

Warner, P.A.; Purvis, W.J.

1984-01-01

276

Reliability test of an electron cyclotron resonance ion source for accelerator driven sub-critical system  

NASA Astrophysics Data System (ADS)

The reliability test of an electron cyclotron resonance ion source developed for accelerator driven sub-critical system is carried out in China Institute of Atomic Energy. A unique technique to improve the reliability is adopted. The source is operated for more than 200 h at 75 keV, 100 mA extracted hydrogen current, while 2 beam trips are recorded in the period, and uninterrupted operation time is about 150 h. The experimental result is described.

Cui, B.; Tang, B.; Ma, R.; Huang, Q.; Ma, Y.; Chen, L.; Jiang, W.

2012-02-01

277

Review: likelihood method for fitting Weibull log-linear models to accelerated life-test data  

Microsoft Academic Search

The analysis of data from accelerated life-test experiments via the method of maximum likelihood estimation must, for a Weibull log-linear model, be performed numerically. This paper promotes a particular log-likelihood as the basis for such inferences, and introduces notation and formulae to aid the implementation of various numerical methods. Two examples illustrate the performance of a widely-used maximization technique; these

Alan J. Watkins; Reader Aids

1994-01-01

278

A New Facility to Test Superconducting Accelerator Magnets in Superfluid Helium  

Microsoft Academic Search

Future high energy accelerators such as the Large Hadron Collider require magnets with the highest possible fields. For NbTi conductor magnets, this means operating at superfluid helium temperatures in the range of 1.8-1.9K. As part of Fermilab's superconducting magnet R&D program, we have built a facility to test magnets in a vertical dewar of superfluid liquid helium. The dewar is

M. J. Lamm; C. Hess; P. J. Limon; D. Orris; T. Peterson; S. Sharonov; J. B. Strait; C. Sylvester; J. Sim; J. C. Tompkins

1997-01-01

279

Development of Free-Electron x-Ray Lasers on the TESLA Test Accelerator (DESY, Germany)  

Microsoft Academic Search

The program for developing free-electron x-ray lasers at TESLA started in 1994. The plan is to use the TESLA test accelerator to develop an x-ray laser with minimum wavelength 0.16 nm. The first phase of the project was successfully completed in 2001. At saturation, the laser produces ultrashort 30100 fsec, gigawatt, radiation pulses. The wavelength can be tuned smoothly over

M. V. Yurkov

2003-01-01

280

Relativistic Klystron Two-Beam Accelerator studies at the RTA test facility  

SciTech Connect

A prototype rf power source based on the Relativistic Klystron Two- Beam Accelerator (RK-TBA) concept is being constructed at LBNL to study physics, engineering, and costing issues. The prototype, called RTA, is described and compared to a full scale design appropriate for driving the Next Linear Collider. Specific details of the induction core test and pulsed power system are presented. Details of the 1-MeV, 1.2-kA induction gun currently under construction are described.

Westenskow, G.A.; Houck, T.L. [Lawrence Livermore National Lab., CA (United States); Anderson, D. [Lawrence Berkeley National Lab., CA (United States)] [and others

1996-08-16

281

Accelerated environmental stress screening & reliability growth testing of the B52 infrared camera  

Microsoft Academic Search

To assure that the final design for the forward looking infrared (FLIR) camera meets the reliability requirements, a specially tailored reliability development growth test (RD\\/GT) plan has been developed. The author describes the RD\\/GT plan, how it was developed, its application of accelerated burn-in methods, and its use of methodologies normally associated with environmental stress screening. The RD\\/GT has two

Timothy J. Donovan; Griffiss AFB

1993-01-01

282

Accelerated Life Testing and Reliability of High K Multilayer Ceramic Capacitors  

Microsoft Academic Search

The reliability of high K muitilayer ceramic capacitors was evaluated using accelerated life testing. The degradation in insulation resistance was characterized as a function of voltage (two to eight times rated) and temperature (85 to 170C). The times to failure at a voltage-temperature stress conformed to a iognormai distribution with a standard deviation typically less than 0.5. A small infant

WILLIAM J. MINFORD

1982-01-01

283

Patterns of erosion from acrylic and fluoropolymer coatings in accelerated and natural weathering tests  

Microsoft Academic Search

Commercial poly (vinylidene difluoride) (PVDF)\\/acrylic coatings show minimal gloss loss or bulk chemical change even after\\u000a sustained Florida or accelerated weathering testing. Previously, we showed that QUV-B weight loss rates can be used as an\\u000a early predictor of the weatherability of fluoropolymer\\/acrylic blend clearcoats. In this work, we study the microscopic basis\\u000a for differences seen between various blends and pure

Kurt A. Wood; Lotfi Hedhli; P. Jeanene Willcox

2002-01-01

284

Intrabeam scattering analysis of measurements at KEK's Accelerator Test Facility damping ring  

Microsoft Academic Search

We derive a simple relation for estimating the relative emittance growth in x and y due to intrabeam scattering (IBS) in electron storage rings. We show that IBS calculations for the Accelerator Test Facility (ATF) damping ring, when using the formalism of Bjorken-Mtingwa, a modified formalism of Piwinski (where eta2\\/beta has been replaced by H), or a simple high-energy approximate

K. L. Bane; H. Hayano; K. Kubo; T. Naito; T. Okugi; J. Urakawa

2002-01-01

285

Coating evaluation and validation of accelerated test conditions using an in-situ corrosion sensor  

Microsoft Academic Search

An in-situ corrosion sensor was used to obtain electrochemical impedance spectroscopy (EIS) measurements on coated panels\\u000a under a variety of accelerated laboratory test conditions as well as ambient exposure at a Florida beach. Three studies are\\u000a reported. The first compared the sensor (EIS) measurements taken in a salt fog chamber to those obtained using a clamp-on\\u000a cell and the conventional

G. D. Davis; L. A. Krebs; C. M. Dacres

2002-01-01

286

Prediction of storage life of hydraulic oils on the basis of accelerated climatic tests  

SciTech Connect

On the basis of changes in physicochemical characteristics of hydraulic oil (kinematic viscosity, solid point, refractive index, density) under the influence of conditions of accelerated climatic tests (ACTs), it is impossible to judge the changes of oil composition with any degree of reliability. Of the components of hydraulic oil, the most sensitive to the combined action of temperature, moisture, and various metals are the aromatic hydrocarbons, oxygen-containing compounds, and the antioxidant diphenylamine.

Lovzin, E.V.; Polyakova, A.A.; Semanyuk, R.N.; Fal`kovskaya, O.I.; Shabalina, T.N.; Tyshchenko, V.A.; Kalinina, L.D.

1994-09-01

287

Test results of the proton injector of the Proton Engineering Frontier Project accelerator  

SciTech Connect

One of the goals of the Proton Engineering Frontier Project (PEFP) is to develop a 100 MeV proton accelerator. As a low energy part, a 20 MeV proton linac has been developed and tested. The 20 MeV accelerator consists of a 50 keV proton injector, a 3 MeV radio frequency quadrupole, and a 20 MeV drift tube linac. The proton injector includes a duoplasmatron type ion source and a low energy beam transport. After a preliminary test with 1 mA peak current of the 20 MeV accelerator, the proton injector was modified with the goal of increasing the 20 MeV beam current up to 20 mA peak value. The modifications include the reduction of the proton injector length, installation of a beam current monitor, and electron trap and supplement of the solenoid and steering magnets. In this paper, the modifications of the PEFP proton injector are described and initial test results are presented.

Kwon, Hyeok-Jung; Kim, Han-Sung; Cho, Yong-Sub [Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of)

2008-02-15

288

Accelerated aging and flashover tests on 138 kV nonceramic line post insulators  

SciTech Connect

The behavior of 138 kV nonceramic line post insulators is investigated by means of clean fog tests conducted before and after aging in a specially designed accelerated aging chamber. The laboratory aging cycles are justified on the basis of actual weather in the coastal regions of Florida. Analytical measurements quantifying the degree of artificial aging are discussed and comparisons of artificial aging with service experience are presented. Observations of audible noise and radio influence voltage during the clean fog tests are reported.

Schneider, H.M.; Guidi, W.W. (EPRI High Voltage Transmission Research Center, Lenox, MA (United States)); Burnham, J.T. (Florida Power and Light Co., Juno Beach (United States)); Gorur, R.S. (Arizona State Univ., Tempe (United States)); Hall, J.F. (Electric Power Research Inst., Palo Alto, CA (United States))

1993-01-01

289

Development of a Dielectric-Loaded Accelerator Test Facility Based on an X-Band Magnicon Amplifier  

NASA Astrophysics Data System (ADS)

The Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), are developing a dielectric-loaded accelerator (DLA) test facility powered by the 11.424-GHz magnicon amplifier that was developed jointly by NRL and Omega-P, Inc. Thus far, DLA structures developed by ANL have been tested at the NRL Magnicon Facility without injected electrons, including tests of alumina and magnesium calcium titanate structures at gradients up to ~8 MV/m. The next step is to inject electrons in order to build a compact DLA test accelerator. The Accelerator Laboratory of Tsinghua University in Beijing, China has developed a 5-MeV electron injector for the accelerator, and SLAC is developing a means to combine the two magnicon output arms, and to drive the injector and an accelerator section with separate control of the power ratio and relative phase. Also, RWBruce Associates, working with NRL, is developing a means to join ceramic tubes to produce long accelerating sections using a microwave brazing process. The installation and commissioning of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year.

Gold, S. H.; Kinkead, A. K.; Gai, W.; Power, J. G.; Konecny, R.; Jing, C.; Tantawi, S. G.; Nantista, C. D.; Hu, Y.; Du, X.; Tang, C.; Lin, Y.; Bruce, R. W.; Bruce, R. L.; Fliflet, A. W.; Lewis, D.

2006-01-01

290

Development of a Dielectric-Loaded Accelerator Test Facility Based on an X-Band Magnicon Amplifier  

SciTech Connect

The Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), are developing a dielectric-loaded accelerator (DLA) test facility powered by the 11.424-GHz magnicon amplifier that was developed jointly by NRL and Omega-P, Inc. Thus far, DLA structures developed by ANL have been tested at the NRL Magnicon Facility without injected electrons, including tests of alumina and magnesium calcium titanate structures at gradients up to {approx}8 MV/m. The next step is to inject electrons in order to build a compact DLA test accelerator. The Accelerator Laboratory of Tsinghua University in Beijing, China has developed a 5-MeV electron injector for the accelerator, and SLAC is developing a means to combine the two magnicon output arms, and to drive the injector and an accelerator section with separate control of the power ratio and relative phase. Also, RWBruce Associates, working with NRL, is developing a means to join ceramic tubes to produce long accelerating sections using a microwave brazing process. The installation and commissioning of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year.

Gold, S. H.; Fliflet, A. W. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Kinkead, A. K. [LET Corporation, Washington, DC 20007 (United States); Gai, W.; Power, J. G.; Konecny, R.; Jing, C. [High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Tantawi, S. G.; Nantista, C. D. [Stanford Linear Accelerator Center, Menlo Park, CA 94025 (United States); Hu, Y.; Du, X.; Tang, C.; Lin, Y. [Tsinghua University, Beijing 100084 (China); Bruce, R. W.; Bruce, R. L. [RWBruce Associates, Inc., Arnold, MD 21012 (United States); Lewis, D. III [Material Science and Technology Division, Naval Research Laboratory (United States)

2006-01-03

291

Cavitation behavior observed in three monoleaflet mechanical heart valves under accelerated testing conditions.  

PubMed

Accelerated testing provides a substantial amount of data on mechanical heart valve durability in a short period of time, but such conditions may not accurately reflect in vivo performance. Cavitation, which occurs during mechanical heart valve closure when local flow field pressure decreases below vapor pressure, is thought to play a role in valve damage under accelerated conditions. The underlying flow dynamics and mechanisms behind cavitation bubble formation are poorly understood. Under physiologic conditions, random perivalvular cavitation is difficult to capture. We applied accelerated testing at a pulse rate of 600 bpm and transvalvular pressure of 120 mm Hg, with synchronized videographs and high-frequency pressure measurements, to study cavitation of the Medtronic Hall Standard (MHS), Medtronic Hall D-16 (MHD), and Omni Carbon (OC) valves. Results showed cavitation bubbles between 340 and 360 micros after leaflet/housing impact of the MHS, MHD, and OC valves, intensified by significant leaflet rebound. Squeeze flow, Venturi, and water hammer effects each contributed to cavitation, depending on valve design. PMID:18356649

Lo, Chi-Wen; Liu, Jia-Shing; Li, Chi-Pei; Lu, Po-Chien; Hwang, Ned H

292

Seismic-fragility tests of new and accelerated-aged Class 1E battery cells  

SciTech Connect

The seismic-fragility response of naturally-aged nuclear station safety-related batteries is of interest for two reasons: (1) to determine actual failure modes and thresholds and (2) to determine the validity of using the electrical capacity of individual cells as an indicator of the potential survivability of a battery given a seismic event. Prior reports in this series discussed the seismic-fragility tests and results for three specific naturally-aged cell types: 12-year old NCX-2250, 10-year old LCU-13, and 10-year old FHC-19. This report focuses on the complementary approach, namely, the seismic-fragility response of accelerated-aged batteries. Of particular interest is the degree to which such approaches accurately reproduce the actual failure modes and thresholds. In these tests the significant aging effects observed, in terms of seismic survivability, were: embrittlement of cell cases, positive bus material and positive plate grids; and excessive sulphation of positive plate active material causing hardening and expansion of positive plates. The IEEE Standard 535 accelerated aging method successfully reproduced seismically significant aging effects in new cells but accelerated grid embrittlement an estimated five years beyond the conditional age of other components.

Bonzon, L.L.; Janis, W.J.; Black, D.A.; Paulsen, G.A.

1987-01-01

293

The relationship between charge passed and the chloride concentrations in anode and cathode cells using the accelerated chloride migration test  

Microsoft Academic Search

In this study the electrochemical technique is applied to accelerate chloride ion migration in cement-based material to estimate\\u000a its permeability. Specimens with six fine aggregate volume fractions were cast and tested. For all test series, the chloride\\u000a concentrations both in anode and cathode cells as well as the electrical current were simultaneously monitored in the accelerated\\u000a chloride migration test. The

C. C. Yang

2003-01-01

294

Electron spin resonance spectral study of PVC and XLPE insulation materials and their life time analysis  

NASA Astrophysics Data System (ADS)

Electron spin resonance (ESR) study is carried out to characterize thermal endurance of insulating materials used in power cable industry. The presented work provides ESR investigation and evaluation of widely used cable insulation materials, namely polyvinyl chloride (PVC) and cross-linked polyethylene (XLPE). The results confirm the fact that PVC is rapidly degrades than XLPE. The study also indicates that colorants and cable's manufacturing processes enhance the thermal resistance of the PVC. It also verifies the powerfulness and the importance of the ESR-testing of insulation materials compared to other tests assumed by International Electrotechnical Commission (IEC) Standard 216-procedure, e.g. weight loss (WL), electric strength (ES) or tensile strength (TS). The estimated thermal endurance parameters by ESR-method show that the other standard methods overestimate these parameters and produce less accurate thermal life time curves of cable insulation materials.

Morsy, M. A.; Shwehdi, M. H.

2006-03-01

295

Concepts for the magnetic design of the MITICA neutral beam test facility ion accelerator  

SciTech Connect

The megavolt ITER injector concept advancement neutral injector test facility will be constituted by a RF-driven negative ion source and by an electrostatic Accelerator, designed to produce a negative Ion with a specific energy up to 1 MeV. The beam is then neutralized in order to obtain a focused 17 MW neutral beam. The magnetic configuration inside the accelerator is of crucial importance for the achievement of a good beam efficiency, with the early deflection of the co-extracted and stripped electrons, and also of the required beam optic quality, with the correction of undesired ion beamlet deflections. Several alternative magnetic design concepts have been considered, comparing in detail the magnetic and beam optics simulation results, evidencing the advantages and drawbacks of each solution both from the physics and engineering point of view.

Chitarin, G. [Consorzio RFX, Corso Stati Uniti 4, 35127 Padova (Italy); Department of Engineering and Management, University of Padova, Vicenza (Italy); Agostinetti, P.; Marconato, N.; Marcuzzi, D.; Sartori, E.; Serianni, G.; Sonato, P. [Consorzio RFX, Corso Stati Uniti 4, 35127 Padova (Italy)

2012-02-15

296

Beam Based HOM Analysis of Accelerating Structures at the TESLA Test Facility Linac  

SciTech Connect

The beam emittance in future linear accelerators for high energy physics and SASE-FEL applications depends highly on the field performance in the accelerating structures, i.e. the damping of higher order modes (HOM). Besides theoretical and laboratory analysis, a beam based analysis technique was established [1] at the TESLA Test Facility (TTF) linac. It uses a charge modulated beam of variable modulation frequency to excite dipole modes. This causes a modulation of the transverse beam displacement, which is observed at a downstream BPM and associated with a direct analysis of the modes at the HOM-couplers. A brief introduction of eigenmodes of a resonator and the concept of the wake potential is given. Emphasis is put on beam instrumentation and signal analysis aspects, required for this beam based HOM measurement technique.

Wendt, M.; Schreiber, S.; Castro, P.; Gossel, A.; /DESY; Huning, M.; /Fermilab; Devanz, G.; Jablonka, M.; Magne, C.; Napoly, O.; /Saclay; Baboi, N.; /SLAC

2005-08-09

297

Design and testing of a DC ion injector suitable for accelerator-driven transmutation  

SciTech Connect

For a number of years, Los Alamos personnel have collaborated with a team of experimentalists at Chalk River Labs (CRL) near Deep River, Ontario, Canada who were pursuing the development of the front end of a high power cw proton accelerator. At the termination of this program last year, Los Alamos acquired this equipment. With the help of internal Laboratory funding and modest defense conversion funds, we have set up and operated the accelerator at Los Alamos. Operational equipment includes a slightly modified Chalk River Injector Test Stand (CRITS) including a 50 keV proton injector and a 1.25 MeV radio-frequency quadrupole (RFQ) with a klystrode rf power system. Substantial upgrading and modification of the ac power system was necessary to provide the required ac voltage (2400 vac) and power (2 MVA) needed for the operation of this equipment. A companion paper describes in detail the first ion source and beam-transport measurements at Los Alamos. Many of the challenges involved in operating an rf linear accelerator to provide neutrons for an accelerator-driven reactor are encountered at the front (low energy) end of this system. The formation of the ion beam, the control of the beam parameters, and the focusing and matching of a highly space-charge-dominated beam are major problems. To address the operating problems in this critical front end, the Accelerator Operations and Technology Division at the Los Alamos National Laboratory has designed the APDF (Accelerator Prototype Demonstration Facility). The front end of this facility is a 75 keV, high-current, ion injector which has been assembled and is now being tested. This paper discusses the design modifications required in going from the 50 keV CRITS injector to the higher current, 75 keV injector. Major innovative changes were made in the design of this injector. This design eliminates all the control electronics and most of the ion source equipment at high potential. Also, a new, high-quality, ion-extractor system has been built. A dual-solenoid lens will be used in the low energy beam transport (LEBT) line to provide the capability of matching the extracted beam to a high-current ADTT linac. This new injector is the first piece of hardware in the APDF program and will be used to develop the long-term, reliable cw beam operation required for ADTT applications.

Schneider, J. David; Meyer, Earl; Stevens, Ralph R. Jr.; Hansborough, Lash; Sherman, Joseph [Accelerator Operations and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 United States of America (United States)

1995-09-15

298

WindoWorks: A flexible program for computerized testing of accelerator control system electronic circuit boards  

SciTech Connect

Since most accelerator control system circuit boards reside in a commercial bus architecture, such as CAMAC or VMEbus, a computerized test station is needed for exercising the boards. This test station is needed for the development of newly designed prototypes, for commissioning newly manufactured boards, for diagnosing boards which have failed in service, and for long term testing of boards with intermittent failure problems. WindoWorks was created to address these needs. It is a flexible program which runs on a PC compatible computer and uses a PC to bus crate interface. WindoWorks was designed to give the user a flexible way to test circuit boards. Each test is incapsulated into a window. By bringing up several different windows the user can run several different tests simultaneously. The windows are sizable, and moveable. They have data entry boxes so that the test can be customized to the users preference. The windows can be used in conjunction with each other in order to create supertests. There are several windows which are generic. They can be used to test basic functions on any VME (or CAMAC) board. There are other windows which have been created to test specific boards. New windows for testing specific boards can be easily created by a Pascal programmer using the WindoWorks framework.

Utterback, J.

1993-09-01

299

Test of pixel detectors for laser-driven accelerated particle beams  

NASA Astrophysics Data System (ADS)

Laser-driven accelerated (LDA) particle beams have due to the unique acceleration process very special properties. In particular they are created in ultra-short bunches of high intensity exceeding more than 107 \\frac{particles}{cm^{2} \\cdot ns} per bunch. Characterization of these beams is very limited with conventional particle detectors. Non-electronic detectors such as imaging plates or nuclear track detectors are, therefore, conventionally used at present. Moreover, all these detectors give only offline information about the particle pulse position and intensity as they require minutes to hours to be processed, calling for a new highly sensitive online device. Here, we present tests of different pixel detectors for real time detection of LDA ion pulses. Experiments have been performed at the Munich 14MV Tandem accelerator with 8-20 MeV protons in dc and pulsed beam, the latter producing comparable flux as a LDA ion pulse. For detection tests we chose the position-sensitive quantum-counting semiconductor pixel detector Timepix which also provides per-pixel energy- or time-sensitivity. Additionally other types of commercially available pixel detectors are being evaluated such as the RadEye1, a large area (25 x 50 mm2) CMOS image sensor. All of these devices are able to resolve individual ions with high spatial- and energy-resolution down to the level of ?m and tens of keV, respectively. Various beam delivering parameters of the accelerator were thus evaluated and verified. The different readout modes of the Timepix detector which is operated with an integrated USB-based readout interface allow online visualization of single and time-integrated events. Therefore Timepix offers the greatest potential in analyzing the beam parameters.

Reinhardt, S.; Granja, C.; Krejci, F.; Assmann, W.

2011-12-01

300

High gradient tests of C-band accelerating system for Japanese XFEL project  

Microsoft Academic Search

The C-band (5712 MHz) accelerating system will be used as the main accelerator for the XFEL\\/SPring-8 project. In order to confirm the performance of the C-band accelerator for the 8 GeV XFEL machine, the same accelerating structure and RF system have been installed in the SCSS prototype accelerator. The C-band accelerator performance has been investigated at the prototype machine.

K. Shirasawa; T. Inagaki; H. Kitamura; T. Shintake; S. Miura; H. Matsumoto; H. Baba

2007-01-01

301

Testing the Acceleration Hypothesis: Fluency Outcomes Utilizing Still- versus Accelerated-Text in Sixth-Grade Students with Reading Disabilities  

ERIC Educational Resources Information Center

|The acceleration hypothesis views reading rate simultaneously as both an independent and dependent variable that can be manipulated to encourage increases in reading indicators (Breznitz, 2006). Within this conceptualization, reading rate represents all the component sub-processes required for proficient reading and presents the opportunity for a

Paige, David D.

2011-01-01

302

HIV self-testing practices among Health Care Workers: feasibility and options for accelerating HIV testing services in Ethiopia  

PubMed Central

Introduction HIV is still an enormous global burden and it is also causing loss of huge health care workers (HCWs) on the already limited human resource capacity in health care services in Sub-Saharan Africa. Variety of methods of accelerating HIV testing is required to increase the rate of HIV testing and expand treatment services. Therefore, this study was aimed to find out the prevalence, feasibility and options of HIV self-testing practices in Ethiopia. Methods A cross-sectional study design triangulated with qualitative method was conducted from February to May, 2012. The data was collected using a semi-structured pretested questionnaire and in-depth interview, at government and private health centers or clinics and hospitals. During the data collection all the available healthcare workers (HCWs) which encompass the internship students including: Medical, Health Officer, Nurses, Midwives and Laboratory students, and health professionals working in the selected health institutions were involved. Results A total of 307 HCWs were included in the analysis and we found that 288(94.4%) of them were ever tested for HIV, of which majority 203 (70.5%) were tested by themselves though 244(80%) of the HCWs had motivation or interest to be tested by themselves. Generally, of the ever tested only 85(29.5%) were tested by the help of health care providers/counselors other than self. Regarding the place where the HCWs had the test, majority 136 (69.4%) tested by themselves at the health facility and the rest were tested at their home, office, market and church. The main reason stated for self-testing was the need for confidentiality for the test result, which was mentioned by 205(82%). Moreover, 35(14.0%) claims lack of time to access the ordinary counseling and testing services. Conclusion This study depicts high rate of HIV self-testing practice among HCWs. This shows that HIV self-testing can be considered as one pillar to increase the HIV-testing services and a means for the HIV prevention and control policy, through increasing HIV testing uptake and awareness of HIV status. However, the implementation may require the role of different stakeholders and decision makers with further study to extend the options.

Kebede, Bekana; Abate, Tatek; Mekonnen, Desalew

2013-01-01

303

Validation of a stable isotope gastric emptying test for normal, accelerated or delayed gastric emptying.  

PubMed

To validate a 13C-Spirulina platensis breath test for measurement of accelerated or delayed gastric emptying, we measured gastric emptying of egg containing 13C-S. platensis and 99mTc-sulphur colloid by breath 13 CO2 every 15 min over 3 h and scintigraphy every 15-30 min over 5 h in 57 healthy volunteers. Thirty-three received no treatment, 10 received erythromycin, and 14 atropine. A generalized linear regression model predicted half-emptying time by scintigraphy (t1/2S) from breath 13CO2 (t1/2B) data. Accuracy was assessed by standard deviation (SD) of differences between t1/2S and t1/2B and by receiver operating characteristic (ROC) curves. Regression models using breath samples at baseline, and 45, 90, 105 and 120 min, predicted t1/2B (mean +/- SD) at 118 +/- 59 min, similar to t1/2S (118 +/- 67 min). Correlation between t1/2B and t1/2S was significant (r=0.88; P < 0.0001). Differences between t1/2S and t1/2B were: 18-19.2 min for t1/2 < 70-150 min, and 68.3 min for t1/2 > 150 min. Breath test detected abnormal emptying with a sensitivity of 86% and specificity of 80%. Thus, the 13C-S. platensis test measures gastric emptying t1/2 for solids, which is accelerated or delayed to mimic a range of conditions from dumping syndrome to severe gastroparesis, with high sensitivity and specificity. Additional breath samples are needed to increase sensitivity in detecting accelerated gastric emptying. PMID:11903917

Viramontes, B E; Kim, D Y; Camilleri, M; Lee, J S; Stephens, D; Burton, D D; Thomforde, G M; Klein, P D; Zinsmeister, A R

2001-12-01

304

A Road Test Comparison of Reaction Times Using an Operational Combined Brake-Accelerator Pedal and the Conventional Brake Pedal.  

National Technical Information Service (NTIS)

The experiment was conducted to compare road test reaction times obtained from a dual-function pedal that was completely integrated into an automobile's accelerating and braking systems. The resultant mean reaction times, measured from seventeen subjects ...

H. W. Higginbotham J. A. Frost

1972-01-01

305

Upgrade of the A0 photoinjector laser system for NML accelerator test facility at Fermilab  

SciTech Connect

The current Fermilab A0 Photoinjector laser system includes a seed laser, a flashlamp pumped multipass amplifier cavity, a flashlamp pumped 2-pass amplifier system followed by an Infra-Red (IR) to Ultra-Violet (UV) conversion stage. However the current system can only deliver up to 800 pulses due to the low efficiency of Nd:Glass used inside multi-pass cavity. In this paper we will report the effort to develop a new multi pass cavity based on Nd:YLF crystal end-pumped by diode laser. We will also discuss the foreseen design of the laser system for the NML accelerator test facility at Fermilab.

Ruan, J.; Edwards, H.; Fliller, R.P., III; Santucci, J.K.; /Fermilab

2007-06-01

306

Simulation and steering in the intertank matching section of the ground test accelerator  

SciTech Connect

The Intertank Matching Section (IMS) of the Ground Test Accelerator (GTA) is a short (36 cm) beamline designed to match the Radio Frequency Quadrupole (RFQ) exit beam into the first Drift Tube LINAC (DTL) tank. The IMS contains two steering quadrupoles (SMQs) and four variable-field focussing quads (VFQs). The SMQs are fixed strength permanent magnet quadrupoles on mechanical actuators capable of transverse movement for the purpose of steering the beam. The upstream and downstream steering quadrupoles are labelled SMQ1 and SMQ4 respectively. Also contained in the IMS are two RF cavities for longitudinal matching.

Yuan, V.W.; Bolme, G.O.; Johnson, K.F.; Mottershead, C.T.; Sander, O.R.; Smith, M.T. [Los Alamos National Lab., NM (United States); Erickson, J.L. [Grumman Energy Systems Division, Bethpage, NY (United States)

1994-10-01

307

ACCELERATED TESTING OF NEUTRON-ABSORBING ALLOYS FOR NUCLEAR CRITICALITY CONTROL  

SciTech Connect

The US Department of Energy requires nuclear criticality control materials be used for storage of highly enriched spent nuclear fuel used in government programs and the storage of commercial spent nuclear fuel at the proposed High-Level Nuclear Waste Geological Repository located at Yucca Mountain, Nevada. Two different metallic alloys (Ni-Cr-Mo-Gd and borated stainless steel) have been chosen for this service. An accelerated corrosion test program to validate these materials for this application is described and a performance comparison is made.

Ronald E. Mizia

2011-10-01

308

Accelerated corrosion tests for protective properties of aluminum and zinc coatings  

Microsoft Academic Search

We perform accelerated corrosion tests of aluminum-zinc coatings according to the B-117 ASTM standard in the following three\\u000a modes: (1) CCT mode, which includes drying at 60C for 4h, holding at a relative humidity of 100% for 2h, and salt spraying\\u000a (pH=6.87.2) at 35C for 2h; (2) AAR mode, which includes drying at 60C and a relative humidity of 2030%

L. Kwiatkowski; J. Kwiecie?; T. Szustkiewicz

1996-01-01

309

Preliminary results from pressure tank test and field acceleration test of New-Profiling float of Japan (NINJA)  

NASA Astrophysics Data System (ADS)

As one of contributions of Japan to the international Argo community, one of Japanese ocean instrument manufacturers, Tsurumi Seiki Co. (TSK), has started the development of original profiling float in 2000. We purchased the four TSK floats in 2001, and performed the pressure tank test and the acceleration field test in the north Pacific. Among four floats, two are carrying SBE41 CTD sensor, and two are carrying TSK-original CTD sensor. In the pressure tank test, by controlling a tank pressure as float controller expects, we created the ideal ocean in a tank for the float. The TSK float successfully worked as was scheduled, and measured profile data when the float was coming up to the surface (i.e. pressure in tank was decreasing). We also performed the ballasting test of weight of the TSK float to drift at 2000dbars (Swift and Riser, 1994). After these tests, we launched two floats with TSK sensor in the north Pacific in June. One of the floats has finished the 20th profile on 26 August 2002 and is still working. The technical message from the float indicates the stable parking near 2000dbars, the stable profiling speed, and no missing profile data. The temperature and salinity data also indicate the stable T-S relations in deeper layer below 1500dbars among profiles. In this presentation, we will also show the results of field test of the floats with SBE sensor, which will be launched in October 2002.

Izawa, K.; Ando, K.; Mizuno, K.; Inoue, A.; Shikama, N.; Takeuchi, K.; Sekimoto, M.

2002-12-01

310

Development of a Dielectric-Loaded Accelerator Test Facility Based on an X-Band Magnicon Amplifier  

Microsoft Academic Search

The Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), are developing a dielectric-loaded accelerator (DLA) test facility powered by the 11.424-GHz magnicon amplifier that was developed jointly by NRL and Omega-P, Inc. Thus far, DLA structures developed by ANL have been tested at the NRL Magnicon Facility without injected electrons,

S. H. Gold; A. K. Kinkead; W. Gai; J. G. Power; R. Konecny; C. Jing; S. G. Tantawi; C. D. Nantista; Y. Hu; X. Du; C. Tang; Y. Lin; R. W. Bruce; R. L. Bruce; A. W. Fliflet; D. Lewis

2006-01-01

311

Accelerated 54{degree}C irradiated test of Shippingport neutron shield tank and HFIR vessel materials  

SciTech Connect

Charpy V-notch specimens (ASTM Type A) and 5.74-mm diameter tension test specimens of the Shippingport Reactor Neutron Shield Tank (NST) (outer wall material) were irradiated together with Charpy V-notch specimens of the Oak Ridge National Laboratory (ORNI), High,, Flux Isotope Reactor (HFIR) vessel (shell material), to 5.07 {times} 10{sup 17} n/cm{sup 2}, E > 1 MeV. The irradiation was performed in the Ford Nuclear Reactor (FNR), a test reactor, at a controlled temperature of 54{degrees}C (130{degrees}F) selected to approximate the prior service temperatures of the cited reactor structures. Radiation-induced elevations in the Charpy 41-J transition temperature and the ambient temperature yield strength were small and independent of specimen test orientation (ASTM LT vs. TL). The observations are consistent with prior findings for the two materials (A 212-B plate) and other like materials irradiated at low temperature (< 200{degrees}C) to low fluence. The high radiation embrittlement sensitivity observed in HFIR vessel surveillance program tests was not found in the present accelerated irradiation test. Response to 288{degrees}C-168 h postirradiation annealing was explored for the NST material. Notch ductility recovery was found independent of specimen test orientation but dependent on the temperature within the transition region at which the specimens were tested.

Hawthorne, J.R. [Materials Engineering Associates, Inc., Lanham, MD (United States); Rosinski, S.T. [Sandia National Labs., Albuquerque, NM (United States)

1993-01-01

312

Accelerated 54[degree]C irradiated test of Shippingport neutron shield tank and HFIR vessel materials  

SciTech Connect

Charpy V-notch specimens (ASTM Type A) and 5.74-mm diameter tension test specimens of the Shippingport Reactor Neutron Shield Tank (NST) (outer wall material) were irradiated together with Charpy V-notch specimens of the Oak Ridge National Laboratory (ORNI), High,, Flux Isotope Reactor (HFIR) vessel (shell material), to 5.07 [times] 10[sup 17] n/cm[sup 2], E > 1 MeV. The irradiation was performed in the Ford Nuclear Reactor (FNR), a test reactor, at a controlled temperature of 54[degrees]C (130[degrees]F) selected to approximate the prior service temperatures of the cited reactor structures. Radiation-induced elevations in the Charpy 41-J transition temperature and the ambient temperature yield strength were small and independent of specimen test orientation (ASTM LT vs. TL). The observations are consistent with prior findings for the two materials (A 212-B plate) and other like materials irradiated at low temperature (< 200[degrees]C) to low fluence. The high radiation embrittlement sensitivity observed in HFIR vessel surveillance program tests was not found in the present accelerated irradiation test. Response to 288[degrees]C-168 h postirradiation annealing was explored for the NST material. Notch ductility recovery was found independent of specimen test orientation but dependent on the temperature within the transition region at which the specimens were tested.

Hawthorne, J.R. (Materials Engineering Associates, Inc., Lanham, MD (United States)); Rosinski, S.T. (Sandia National Labs., Albuquerque, NM (United States))

1993-01-01

313

Accelerated Testing of Epoxy-FRP Composites for Civil Infrastructure Applications: Property Changes and Mechanisms of Degradation  

Microsoft Academic Search

Accelerated testing of FRP systems is frequently performed due to the long service life of these materials used to repair damaged civil structures. This testing typically involves exposure to common environmental conditions seen in the field. However, the main limitation of these experiments is that the testing protocols typically do not consider a change in the failure mechanism as a

Andrew Stewart; Elliot P. Douglas

2012-01-01

314

Lessons from two field tests on pipeline damage detection using acceleration measurement  

NASA Astrophysics Data System (ADS)

Early detection of pipeline damages has been highlighted in water supply industry. Water pressure change in pipeline due to a sudden rupture causes pipe to vibrate and the pressure change propagates through the pipeline. From the measurement of pipe vibration the rupture can be detected. In this paper, the field test results and observations are provided for implementing next generation of SCADA system for pipeline rupture detection. Two field tests were performed on real buried plastic and metal pipelines for rupture detection. The rupture was simulated by introducing sudden water pressure drop caused by water blow-off and valve control. The measured acceleration data at the pipe surfaces were analyzed in both time and frequency domain. In time domain, the sudden narrow increase of acceleration amplitude was used as an indication of rupture event. For the frequency domain analysis, correlation function and the short time Fourier Transform technique were adopted to trace the dominant frequency shift. The success of rupture detection was found to be dependent on several factors. From the frequency analysis, the dominant frequency of metal water pipe was shifted by the water pressure drop, however, it was hard to identify from the plastic pipeline. Also the influence of existing facility such as airvac on pipe vibrations was observed. Finally, several critical lessons learned in the viewpoint of field measurement are discussed in this paper.

Shinozuka, Masanobu; Lee, Sungchil; Kim, Sehwan; Chou, Pai H.

2011-03-01

315

Accelerated cosmological models in modified gravity tested by distant supernovae SNIa data  

SciTech Connect

Recent type Ia supernova measurements and other astronomical observations suggest that our Universe is, at the present epoch, in an accelerating phase of evolution. While a dark energy of unknown form and origin is usually proposed as the most feasible mechanism for the acceleration, there appeared some generalizations of Einstein equations which could mimic dark energy. In this work we investigate observational constraints on a modified Friedmann equation obtained from the generalized Lagrangian L{proportional_to}R{sup n} minimally coupled with matter via the Palatini first-order formalism. We mainly concentrate on such restrictions of model parameters which can be derived from distant supernovae and baryon oscillation tests. We obtain confidence levels for two parameters (n, {omega}{sub m,0}) and find, from combined analysis, that the preferred value of {omega}{sub m,0} equals 0.3. For deeper statistical analysis and for comparison of our model with predictions of the {lambda}CDM concordance model, one applies Akaike and Bayesian information criteria of model selection. Finally, we conclude that the Friedmann-Robertson-Walker model merged with a first-order nonlinear gravity survives SNIa and baryon oscillation tests.

Borowiec, Andrzej [Institute of Theoretical Physics, University of Wroclaw, pl. Maksa Borna 9, 50-204 Wroclaw (Poland) (Poland); Godlowski, Wlodzimierz [Astronomical Observatory , Jagiellonian University, 30-244 Cracow, ul. Orla 171 (Poland); Szydlowski, Marek [Astronomical Observatory , Jagiellonian University, 30-244 Cracow, ul. Orla 171 (Poland) and Mark Kac International Centre for Complex and Quantum Systems, Institute of Physics, Jagiellonian University, 30-244 Cracow, ul. Orla 171 (Poland)

2006-08-15

316

Vacuum-to-air interface for the advanced test accelerator beam director  

SciTech Connect

A vacuum-to-air transition was created to facilitate the Lawrence Livermore National Laboratory's Advanced Test Accelerator (ATA) electron beam 1-Hz pulse rate. It is necessary that a pulsed particle beam go from a region at 10/sup -6/ torr through a 1-cm-diam maximum aperture into a region at 760 torr. This must be accomplished without the use of windows or solid barriers. Two tests will be conducted on the vacuum-to-air interface. The first determines pressure profiles through 1.0-mm- and 10.0-mm-diam orifices. The second test employs an expendable foil and foil advancement mechanism. In this paper, the experimental results of the orifice test are presented and the analytical results are compared with the empirical results. The foil advancement test will be documented after the test is completed. The mechanism serves both as an orifice and as a fast-acting vacuum valve. In operation, the electron beam penetrates the thin foil, thereby creating an aperture of minimum geometry. During the balance of the pulse cycle, after the beam duration, the foil is advanced to seal the opening and recover the almost negligible loss in vacuum.

Cruz, G.E.; Edwards, W.F.; Kavanagh, D.P.; Addis, R.B.; Weiss, W.C.; Livenspargar, C.M.

1986-01-01

317

Test Results of a Superconducting Quadrupole Model Designed for Linear Accelerator Applications  

SciTech Connect

The first model of a superconducting quadrupole for use in a Linear Accelerator was designed, built and tested at Fermilab. The quadrupole has a 78 mm aperture, and a cold mass length of 680 mm. A superferric magnet configuration with iron poles and four racetrack coils was chosen based on magnet performance, cost, and reliability considerations. Each coil is wound using enamel insulated, 0.5 mm diameter, NbTi superconductor. The quadrupole package also includes racetrack type dipole steering coils. The results of the quadrupole design, manufacturing and test, are presented. Specific issues related to the quadrupole magnetic center stability, superconductor magnetization and mechanical stability are discussed. The magnet quench performance and results of magnetic measurements will also be briefly discussed.

Kashikhin, Vladimir S.; Andreev, Nikolai; Chlachidze, Guram; DiMarco, Joseph; Kashikhin, Vadim V.; Lamm, Michael J.; Lopes, Mauricio L.; Orris, Darryl; Tartaglia, Michael; Tompkins, John C.; Velev, Gueorgui; /Fermilab

2008-08-01

318

A study on the improvement of mold life-time in UV nanoimprint  

Microsoft Academic Search

Long mold-life time is great important for roll-to-roll process in UV nanoimprint. We investigated the cause of the decay of the releasing performance by various surface characterization methods. We optimized the coating condition of the releasing agent, and we have achieved the elongation of the mold life-time.

Satoru Ozawa; Yuusuke Nakai; Tetsuya Jigami; Shigeo Wakabayashi; Tadayuki Fujiwara

2011-01-01

319

Models of f(R) cosmic acceleration that evade solar system tests  

SciTech Connect

We study a class of metric-variation f(R) models that accelerates the expansion without a cosmological constant and satisfies both cosmological and solar-system tests in the small-field limit of the parameter space. Solar-system tests alone place only weak bounds on these models, since the additional scalar degree of freedom is locked to the high-curvature general-relativistic prediction across more than 25 orders of magnitude in density, out through the solar corona. This agreement requires that the galactic halo be of sufficient extent to maintain the galaxy at high curvature in the presence of the low-curvature cosmological background. If the galactic halo and local environment in f(R) models do not have substantially deeper potentials than expected in {lambda}CDM, then cosmological field amplitudes |f{sub R}| > or approx.10{sup -6} will cause the galactic interior to evolve to low curvature during the acceleration epoch. Viability of large-deviation models therefore rests on the structure and evolution of the galactic halo, requiring cosmological simulations of f(R) models, and not directly on solar-system tests. Even small deviations that conservatively satisfy both galactic and solar-system constraints can still be tested by future, percent-level measurements of the linear power spectrum, while they remain undetectable to cosmological-distance measures. Although we illustrate these effects in a specific class of models, the requirements on f(R) are phrased in a nearly model-independent manner.

Hu, Wayne [Kavli Institute for Cosmological Physics, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States); Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637 (United States); Sawicki, Ignacy [Kavli Institute for Cosmological Physics, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States)

2007-09-15

320

a Development of Accelerated Life Test Method for Blower Motor for Automobile Using Inverse Power Law Model  

NASA Astrophysics Data System (ADS)

Reliability of automotive parts has been one of the most interesting fields in the automotive industry. Especially small DC motor was issued because of the increasing adoption for passengers' safety and convenience. This study was performed to develop the accelerated life test method using Inverse power law model for small DC motors. The failure mode of small DC motor includes brush wear-out. Inverse power law model is applied effectively the electronic components to reduce the testing time and to achieve the accelerating test conditions. Accelerated life testing method was induced to bring on the brush wear-out as increasing voltage of motor. Life distribution of the small DC motor was supposed to follow Weibull distribution and life test time was calculated under the conditions of B10 life and 90% confidence level.

Shin, Wae-Gyeong; Lee, Soo-Hong

321

Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head  

SciTech Connect

For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110-watt Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head.

Krause, David L. [National Aeronautics and Space Administration, Glenn Research Center, Cleveland, OH 44135 (United States); Kantzos, Pete T. [Ohio Aerospace Institute, NASA Glenn Research Center, Cleveland, OH 44135 (United States)

2006-01-20

322

Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head  

NASA Astrophysics Data System (ADS)

For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110-watt Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head.

Krause, David L.; Kantzos, Pete T.

2006-01-01

323

Accelerated in vitro durability testing of nonvascular Nitinol stents based on the electrical potential sensing method  

NASA Astrophysics Data System (ADS)

In this paper, we report an evaluation of the performance of a new stent durability tester based on the electrical potential sensing method through accelerated in vitro testing of six different nonvascular Nitinol stents simulating physiological conditions. The stents were subjected to a pulsatile loading of 33 Hz for a total of 62,726,400 cycles, at constant temperature and pressure of 350.5 C and 1204 mmHg, respectively. The electrical potential of each stent was measured in real-time and monitored for any changes in readings. After conducting test-to-fracture tests, the stents were visually checked, and by scanning electron microscopy. A sudden electrical potential drop in the readings suggests a fracture has occurred, and the only two instances of fracture in our present results were correctly determined by our present device, with the fractures confirmed visually after the test. The excellent performance of our new method shows good potential for a highly reliable and applicable in vitro durability testing for different kinds and sizes of metallic stents.

Park, Chan-Hee; Tijing, Leonard D.; Pant, Hem Raj; Kim, Tae-Hyung; Amarjargal, Altangerel; Kim, Han Joo; Kim, Cheol Sang

2013-09-01

324

Corrosion characterization of durable silver coatings by electrochemical impedance spectroscopy and accelerated environmental testing  

NASA Astrophysics Data System (ADS)

Highly reflective front-surface silver mirrors are needed for many optical applications. While various protective dielectric coating schemes have been developed, the long-term durability of Ag mirrors is still of great concern in the optics community for a variety of applications under harsh environments. The corrosion protection behavior of a SiNx-coated silver-mirror coating scheme was tested with electrochemical impedance spectroscopy (EIS) and accelerated environmental testing, including humidity and salt fog tests. The EIS data obtained were fitted with different equivalent circuit models. The results suggested that the 100 thick SiNx coating produced by rf magnetron sputtering was porous and acted as a leaky capacitor on the Ag film, whereas the addition of a NiCrNx interlayer as thin as 3 between SiNx and Ag films resulted in a much denser SiNx coating with a low-frequency impedance value of 2 orders of magnitude higher than that without the interlayer. Humidity and salt fog testing of different silver coatings showed similar results. The 100 SiNx/3-NiCrNx/Ag coating exhibited excellent corrosion resistance against the corrosive environments used in this study.

Chu, Chung-Tse; Fuqua, Peter D.; Barrie, James D.

2006-03-01

325

Corrosion characterization of durable silver coatings by electrochemical impedance spectroscopy and accelerated environmental testing.  

PubMed

Highly reflective front-surface silver mirrors are needed for many optical applications. While various protective dielectric coating schemes have been developed, the long-term durability of Ag mirrors is still of great concern in the optics community for a variety of applications under harsh environments. The corrosion protection behavior of a SiNx-coated silver-mirror coating scheme was tested with electrochemical impedance spectroscopy (EIS) and accelerated environmental testing, including humidity and salt fog tests. The EIS data obtained were fitted with different equivalent circuit models. The results suggested that the 100A thick SiNx coating produced by rf magnetron sputtering was porous and acted as a leaky capacitor on the Ag film, whereas the addition of a NiCrNx interlayer as thin as 3A between SiNx and Ag films resulted in a much denser SiNx coating with a low-frequency impedance value of 2 orders of magnitude higher than that without the interlayer. Humidity and salt fog testing of different silver coatings showed similar results. The 100A SiNx/3A-NiCrNx/Ag coating exhibited excellent corrosion resistance against the corrosive environments used in this study. PMID:16539267

Chu, Chung-Tse; Fuqua, Peter D; Barrie, James D

2006-03-01

326

A new approach of studying correlation between outdoor exposure and indoor accelerated corrosion test for high polymer materials  

Microsoft Academic Search

The correlation between outdoor exposure and indoor accelerated corrosion test for high polymer materials was investigated\\u000a according to the variation of the functional group of exposure models aged. Environment aging intesities at different zones\\u000a (Wuhan and Lasa with the same latitude) and the influences of indoor accelerating factors including water and ultraviolet\\u000a on weathering performance of high polymer materials were

Yang Lixia; Li Xiaogang; Zhang Sanping

2006-01-01

327

High power breakdown testing of a photonic band-gap accelerator structure with elliptical rods  

NASA Astrophysics Data System (ADS)

An improved single-cell photonic band-gap (PBG) structure with an inner row of elliptical rods (PBG-E) was tested with high power at a 60 Hz repetition rate at X-band (11.424 GHz), achieving a gradient of 128MV/m at a breakdown probability of 3.610-3 per pulse per meter at a pulse length of 150 ns. The tested standing-wave structure was a single high-gradient cell with an inner row of elliptical rods and an outer row of round rods; the elliptical rods reduce the peak surface magnetic field by 20% and reduce the temperature rise of the rods during the pulse by several tens of degrees, while maintaining good damping and suppression of high order modes. When compared with a single-cell standing-wave undamped disk-loaded waveguide structure with the same iris geometry under test at the same conditions, the PBG-E structure yielded the same breakdown rate within measurement error. The PBG-E structure showed a greatly reduced breakdown rate compared with earlier tests of a PBG structure with round rods, presumably due to the reduced magnetic fields at the elliptical rods vs the fields at the round rods, as well as use of an improved testing methodology. A post-testing autopsy of the PBG-E structure showed some damage on the surfaces exposed to the highest surface magnetic and electric fields. Despite these changes in surface appearance, no significant change in the breakdown rate was observed in testing. These results demonstrate that PBG structures, when designed with reduced surface magnetic fields and operated to avoid extremely high pulsed heating, can operate at breakdown probabilities comparable to undamped disk-loaded waveguide structures and are thus viable for high-gradient accelerator applications.

Munroe, Brian J.; Cook, Alan M.; Shapiro, Michael A.; Temkin, Richard J.; Dolgashev, Valery A.; Laurent, Lisa L.; Lewandowski, James R.; Yeremian, A. Dian; Tantawi, Sami G.; Marsh, Roark A.

2013-01-01

328

Tensile strength at elevated temperature and its applicability as an accelerated testing methodology for unidirectional composites  

NASA Astrophysics Data System (ADS)

The applicability of a macroscopic time-temperature superposition principle (TTSP) to unidirectional composite strength is discussed based on the microscopic Simultaneous Fiber-Failure (SFF) model that has been presented by Koyanagi et al. (J. Compos. Mater. 43:1901-1914, 2009a). The SFF model estimates composite strengths as functions of fiber, matrix, and interface strengths. This paper first investigates the applicability of SFF to the complicated temperature dependence of composite strengths, i.e., one composite exhibits significant temperature dependence and another does not, considering the temperature dependence of the components, which results in successful estimations for the two composite systems used in the present study. The long-term durability predicted by the SFF and that predicted by the TTSP are then compared. They typically correspond to each other in various cases; accelerated testing methodology (ATM) employing TTSP is thus proved to be valid from the micromechanical viewpoint, assuming the SFF applicability.

Koyanagi, Jun; Nakada, Masayuki; Miyano, Yasushi

2012-02-01

329

Extremely low vertical-emittance beam in accelerator-test facility at KEK  

SciTech Connect

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping rings which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1 percent of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10{sup -8} rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.

Kubo, K.; Akemoto, M.; Anderson, S.; Aoki, T.; Araki, S.; Bane, K.L.F.; Blum, P.; Corlett, J.; Dobashi, K.; Emma, P.; Frisch, J.; Fukuda, M.; Guo, Z.; Hasegawa, K.; Hayano, H.; Higo, T.; Higurashi, A.; Honda, Y.; Iimura, T.; Imai, T.; Jobe, K.; Kamada, S.; Karataev, P.; Kashiwagi, S.; Kim, E.; Kobuki, T.; Kotseroglou, T.; Kurihara, Y.; Kuriki, M.; Kuroda, R.; Kuroda, S.; Lee, T.; Luo, X.; McCormick, D.J.; McKee, B.; Mimashi, T.; Minty, M.; Muto, T.; Naito, Takashi; Naumenko, G.; Nelson, J.; Nguyen, M.N.; Oide, K.; Okugi, T.; Omori, T.; Oshima, T.; Pei, G.; Potylitsyn, A.; Qin, Q.; Raubenheimer, T.; Ross, M.; Sakai, H.; Sakai, I.; Schmidt, F.; Slaton, T.; Smith, H.; Smith, S.; Suzuki, Toshikazu; Takano, M.; Takeda, Seishi; Terunuma, N.; Toge, N.; Turner, J.; Urakawa, J.; Vogel, V.; Woodley, M.; Yocky, J.; Young, A.; Zimmerman, F.; ATF Collaboration

2002-05-13

330

Simulation and steering in the Intertank matching section of the ground test accelerator  

SciTech Connect

The Intertank Matching Section (IMS) of the Ground Test Accelerator (GTA) is a short (36 cm) beamline designed to match the Radio Frequency Quadrupole (RFQ) exit beam into the first Drift Tube LINAC (DTL) tank. The IMS contains two steering quadrupoles (SMQS) and four variable-field focusing quads (VFQs). The SMQs are fixed strength permanent magnet quadrupoles on mechanical actuators capable of transverse movement for the purpose of steerng the beam. Also contained in the IMS are two RF cavities for longitudinal matching. A comparison of measured to calculated steering coefficients has been made for data aken in 3 different tunes of the IMS transport line. (AIP) {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Yuan, V.W.; Bolme, G.O.; Erickson, J.L.; Johnson, K.F.; Mottershead, C.T.; Sander, O.R.; Smith, M.T. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1995-05-05

331

600 kV modulator design for the SLAC Next Linear Collider Test Accelerator  

SciTech Connect

Preliminary design for the SLAC Next Linear Collider Test Accelerator (NLCTA) requires a pulse power source to produce a 600 kV, 600 A, 1.4 {mu}s, 0.1% flat top pulse with rise and fall times of approximately 100 ns to power an X-Band klystron with a microperveance of 1.25 at {approx} 100 MW peak RF power. The design goals for the modulator, including those previously listed, are peak modulator pulse power of 340 MW operating at 120 Hz. A three-stage darlington pulse-forming network, which produces a >100 kV, 1.4 {mu}s pulse, is coupled to the klystron load through a 6:1 pulse transformer. Careful consideration of the transformer leakage inductance, klystron capacitance, system layout, and component choice is necessary to produce the very fast rise and fall times at 600 kV operating continuously at 120 Hz.

Harris, K.; de Lamare, J.; Nesterov, V.; Cassel, R.

1992-07-01

332

Extremely low vertical-emittance beam in the accelerator test facility at KEK.  

PubMed

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance. PMID:12005637

Kubo, K; Akemoto, M; Anderson, S; Aoki, T; Araki, S; Bane, K L F; Blum, P; Corlett, J; Dobashi, K; Emma, P; Frisch, J; Fukuda, M; Guo, Z; Hasegawa, K; Hayano, H; Higo, T; Higurashi, A; Honda, Y; Iimura, T; Imai, T; Jobe, K; Kamada, S; Karataev, P; Kashiwagi, S; Kim, E; Kobuki, T; Kotseroglou, T; Kurihara, Y; Kuriki, M; Kuroda, R; Kuroda, S; Lee, T; Luo, X; McCormick, D J; McKee, B; Mimashi, T; Minty, M; Muto, T; Naito, Takashi; Naumenko, G; Nelson, J; Nguyen, M N; Oide, K; Okugi, T; Omori, T; Oshima, T; Pei, G; Potylitsyn, A; Qin, Q; Raubenheimer, T; Ross, M; Sakai, H; Sakai, I; Schmidt, F; Slaton, T; Smith, H; Smith, S; Smith, T; Suzuki, Toshikazu; Takano, M; Takeda, Seishi; Terunuma, N; Toge, N; Turner, J; Urakawa, J; Vogel, V; Woodley, M; Yocky, J; Young, A; Zimmermann, F

2002-04-30

333

Extremely Low Vertical-Emittance Beam in the Accelerator Test Facility at KEK  

NASA Astrophysics Data System (ADS)

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.810-8 rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.

Kubo, K.; Akemoto, M.; Anderson, S.; Aoki, T.; Araki, S.; Bane, K. L.; Blum, P.; Corlett, J.; Dobashi, K.; Emma, P.; Frisch, J.; Fukuda, M.; Guo, Z.; Hasegawa, K.; Hayano, H.; Higo, T.; Higurashi, A.; Honda, Y.; Iimura, T.; Imai, T.; Jobe, K.; Kamada, S.; Karataev, P.; Kashiwagi, S.; Kim, E.; Kobuki, T.; Kotseroglou, T.; Kurihara, Y.; Kuriki, M.; Kuroda, R.; Kuroda, S.; Lee, T.; Luo, X.; McCormick, D. J.; McKee, B.; Mimashi, T.; Minty, M.; Muto, T.; Naito, Takashi; Naumenko, G.; Nelson, J.; Nguyen, M. N.; Oide, K.; Okugi, T.; Omori, T.; Oshima, T.; Pei, G.; Potylitsyn, A.; Qin, Q.; Raubenheimer, T.; Ross, M.; Sakai, H.; Sakai, I.; Schmidt, F.; Slaton, T.; Smith, H.; Smith, S.; Smith, T.; Suzuki, Toshikazu; Takano, M.; Takeda, Seishi; Terunuma, N.; Toge, N.; Turner, J.; Urakawa, J.; Vogel, V.; Woodley, M.; Yocky, J.; Young, A.; Zimmermann, F.

2002-05-01

334

Achievement of Ultralow Emittance Beam in the Accelerator Test Facility Damping Ring  

NASA Astrophysics Data System (ADS)

For high luminosity in electron-positron linear colliders, it is essential to generate low vertical emittance beams. We report on the smallest vertical emittance achieved in single-bunch-mode operation of the Accelerator Test Facility, which satisfies the requirement of the x-band linear collider. The emittances were measured with a laser-wire beam-profile monitor installed in the damping ring. The bunch length and the momentum spread of the beam were also recorded under the same conditions. The smallest vertical rms emittance measured at low intensity is 4pm at a beam energy of 1.3GeV, which corresponds to the normalized emittance of 1.01.0-8 m. It increases by a factor of 1.5 for a bunch intensity of 1010 electrons. The measured data agreed to the calculation of intrabeam scattering within much better than a factor of 2.

Honda, Y.; Kubo, K.; Anderson, S.; Araki, S.; Bane, K.; Brachmann, A.; Frisch, J.; Fukuda, M.; Hasegawa, K.; Hayano, H.; Hendrickson, L.; Higashi, Y.; Higo, T.; Hirano, K.; Hirose, T.; Iida, K.; Imai, T.; Inoue, Y.; Karataev, P.; Kuriki, M.; Kuroda, R.; Kuroda, S.; Luo, X.; McCormick, D.; Matsuda, M.; Muto, T.; Nakajima, K.; Naito, Takashi; Nelson, J.; Nomura, M.; Ohashi, A.; Omori, T.; Okugi, T.; Ross, M.; Sakai, H.; Sakai, I.; Sasao, N.; Smith, S.; Suzuki, Toshikazu; Takano, M.; Taniguchi, T.; Terunuma, N.; Turner, J.; Toge, N.; Urakawa, J.; Vogel, V.; Woodley, M.; Wolski, A.; Yamazaki, I.; Yamazaki, Yoshio; Yocky, G.; Young, A.; Zimmermann, F.

2004-02-01

335

Achievement of ultralow emittance beam in the accelerator test facility damping ring.  

PubMed

For high luminosity in electron-positron linear colliders, it is essential to generate low vertical emittance beams. We report on the smallest vertical emittance achieved in single-bunch-mode operation of the Accelerator Test Facility, which satisfies the requirement of the x-band linear collider. The emittances were measured with a laser-wire beam-profile monitor installed in the damping ring. The bunch length and the momentum spread of the beam were also recorded under the same conditions. The smallest vertical rms emittance measured at low intensity is 4 pm at a beam energy of 1.3 GeV, which corresponds to the normalized emittance of 1.0x1.0(-8) m. It increases by a factor of 1.5 for a bunch intensity of 10(10) electrons. The measured data agreed to the calculation of intrabeam scattering within much better than a factor of 2. PMID:14995314

Honda, Y; Kubo, K; Anderson, S; Araki, S; Bane, K; Brachmann, A; Frisch, J; Fukuda, M; Hasegawa, K; Hayano, H; Hendrickson, L; Higashi, Y; Higo, T; Hirano, K; Hirose, T; Iida, K; Imai, T; Inoue, Y; Karataev, P; Kuriki, M; Kuroda, R; Kuroda, S; Luo, X; McCormick, D; Matsuda, M; Muto, T; Nakajima, K; Naito, Takashi; Nelson, J; Nomura, M; Ohashi, A; Omori, T; Okugi, T; Ross, M; Sakai, H; Sakai, I; Sasao, N; Smith, S; Suzuki, Toshikazu; Takano, M; Taniguchi, T; Terunuma, N; Turner, J; Toge, N; Urakawa, J; Vogel, V; Woodley, M; Wolski, A; Yamazaki, I; Yamazaki, Yoshio; Yocky, G; Young, A; Zimmermann, F

2004-02-06

336

Accelerated testing of metal foil tape joints and their effect of photovoltaic module reliability.  

SciTech Connect

A program is underway at Sandia National Laboratories to predict long-term reliability of photovoltaic (PV) systems. The vehicle for the reliability predictions is a Reliability Block Diagram (RBD), which models system behavior. Because this model is based mainly on field failure and repair times, it can be used to predict current reliability, but it cannot currently be used to accurately predict lifetime. In order to be truly predictive, physics-informed degradation processes and failure mechanisms need to be included in the model. This paper describes accelerated life testing of metal foil tapes used in thin-film PV modules, and how tape joint degradation, a possible failure mode, can be incorporated into the model.

Puskar, Joseph David; Quintana, Michael A.; Sorensen, Neil Robert; Lucero, Samuel J.

2009-07-01

337

Rail Profile Grinding on High-Hardness Premium Rail at the Facility for Accelerated Service Testing. Research Results.  

National Technical Information Service (NTIS)

Since 2003, Transportation Technology Center, Inc. (TTCI) has been evaluating the effects of rail grinding on the performance of high-hardness premium rail at the Facility for Accelerated Service Testing (FAST). A 6-degree test curve is divided into three...

2008-01-01

338

OVERVIEW OF AN ACCELERATED PAVEMENT TESTING STUDY TO ASSESS THE PERFORMANCE OF MODIFIED BINDERS IN ASPHALT CONCRETE OVERLAYS  

Microsoft Academic Search

A comprehensive laboratory and accelerated pavement testing study on the use of terminal blend modified binders to limit reflective cracking in thin asphalt concrete overlays has recently been completed at the University of California Pavement Research Center. The experiment entailed the construction of a 90 m test road consisting of compacted clay subgrade, a 410 mm aggregate base and 90

D Jones; J Harvey; T Bressette

339

TARGET: thermal accelerated reliability go-no-go environmental testing dynamic board thermal shock using a single liquid fluorocarbon bath  

Microsoft Academic Search

TARGET, a novel method of accelerated thermal stress for board testing, is described. This method utilizes Fluorinert as the medium for rapid thermal energy transfer. Possible applications include environments for STRIFE testing and board debug. One of the most promising applications is in-line environmental stress screening (ESS). Boards receive a thorough temperature stress screen in the time taken for conventional

Bradford P. Beaton

1991-01-01

340

Outdoor and accelerated weathering tests for polypropylene and polypropylene\\/talc composites: A comparative study of their weathering behavior  

Microsoft Academic Search

In this study, the comparisons of degradation behavior of polypropylene(PP) and PP\\/talc composites were carried out with one outdoor weathering test and three accelerated weathering (xenon, metal halide and carbon arc lamps) tests, respectively. The outdoor exposure vigorously advanced these degradations with the lowest amount of UV exposure energy. It was found that the degradation rates were affected by the

Y. Azuma; H. Takeda; S. Watanabe; H. Nakatani

2009-01-01

341

Cavity Digital Control Testing System By Simulink Step Operation Method For TESLA Linear Accelerator And Free Electron Laser  

Microsoft Academic Search

The cavity control system for the TESLA - TeV-Energy Superconducting Linear Accelerator project is initially introduced in this paper. The FPGA - Field Programmable Gate Array technology has been implemented for digital controller stabilizing cavity field gradient. The cavity SIMULINK model has been applied to test the hardware controller. The step operation method has been developed for testing the FPGA

Tomasz Czarski; Ryszard Romaniuk; Stefan Simrock

2003-01-01

342

Cavity digital control testing system by Simulink step operation method for TESLA linear accelerator and free electron laser  

Microsoft Academic Search

The cavity control system for the TESLA -- TeV-Energy Superconducting Linear Accelerator project is initially introduced in this paper. The FPGA -- Field Programmable Gate Array technology has been implemented for digital controller stabilizing cavity field gradient. The cavity SIMULINK model has been applied to test the hardware controller. The step operation method has been developed for testing the FPGA

Tomasz Czarski; Ryszard S. Romaniuk; Krzysztof T. Pozniak; Stefan Simrock

2004-01-01

343

Reactor IBR-2 Physical Start-Up. Prompt Neutron Life Time Measurement.  

National Technical Information Service (NTIS)

Prompt neutron life time tau for the IBR-2 core without sodium was measured by means of Rossi- alpha method, comparison between experimental and calculated neutron pulse shape, power spectra analysis, and experimental dependence of the peak pulse power di...

V. V. Gusev W. Gudowski V. V. Dmitrienko

1979-01-01

344

Trajectory measurements and correlations in the final focus beam line at the KEK Accelerator Test Facility  

NASA Astrophysics Data System (ADS)

The Accelerator Test Facility 2 (ATF2) commissioning group aims to demonstrate the feasibility of the beam delivery system of the next linear colliders (ILC and CLIC) as well as to define and to test the tuning methods. As the design vertical beam sizes of the linear colliders are about few nanometers, the stability of the trajectory as well as the control of the aberrations are very critical. ATF2 commissioning started in December 2008, and thanks to submicron resolution beam position monitors (BPMs), it has been possible to measure the beam position fluctuation along the final focus of ATF2 during the 2009 runs. The optics was not the nominal one yet, with a lower focusing to make the tuning easier. In this paper, a method to measure the noise of each BPM every pulse, in a model-independent way, will be presented. A method to reconstruct the trajectorys fluctuations is developed which uses the previously determined BPM resolution. As this reconstruction provides a measurement of the beam energy fluctuations, it was also possible to measure the horizontal and vertical dispersion function at each BPMs parasitically. The spatial and angular dispersions can be fitted from these measurements with uncertainties comparable with usual measurements.

Renier, Y.; Bambade, P.; Tauchi, T.; White, G. R.; Boogert, S.

2013-06-01

345

Accelerated exposure tests of encapsulated Si solar cells and encapsulation materials  

SciTech Connect

We have conducted a series of accelerated exposure test (AET) studies for various crystalline-Si (c-Si) and amorphous-Si (a-Si) cell samples that were encapsulated with different superstrates, pottants, and substrates. Nonuniform browning patterns of ethylene vinyl acetate (EVA) pottants were observed for glass/EVA/glass-encapsulated c-Si cell samples under solar simulator exposures at elevated temperatures. The polymer/polymer-configured laminates with Tedlar or Tefzel did not discolor because of photobleaching reactions, but yellowed with polyester or nylon top films. Delamination was observed for the polyester/EVE layers on a-Si minimodules and for a polyolefin-based thermoplastic pottant at high temperatures. For all tested c-Si cell samples, irregular changes in the current-voltage parameters were observed that could not be accounted for simply by the transmittance changes of the superstrate/pottant layers. Silicone-type adhesives used under UV-transmitting polymer top films were observed to cause greater cell current/efficiency loss than EVA or polyethylene pottants. {copyright} {ital 1999 American Institute of Physics.}

Pern, F.J.; Glick, S.H. [Engineering and Reliability Division, National Center for Photovoltaics, National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, Colorado 80401 (United States)

1999-03-01

346

Testing MOND over a Wide Acceleration Range in X-Ray Ellipticals  

NASA Astrophysics Data System (ADS)

The gravitational fields of two isolated ellipticals, NGC 720 and NGC 1521, have been recently measured to very large galactic radii (100 and 200kpc), assuming hydrostatic balance of the hot gas enshrouding them. They afford, for the first time to my knowledge, testing modified Newtonian dynamics (MOND) in ellipticals with force and quality that, arguably, approach those of rotation-curve tests in disk galaxies. In the context of MOND, it is noteworthy that the measured accelerations span a wide range, from more than 10a0 to about 0.1a0, unprecedented in individual ellipticals. I find that MOND predicts correctly the measured dynamical mass runs (apart from a possible minor tension in the inner few kpc of NGC 720, which might be due to departure from hydrostatic equilibrium): The predicted mass discrepancy increases outward from none near the center, to 10 at the outermost radii. The implications for the MOND-versus-dark-matter controversy go far beyond the simple fact of two more galaxies conforming to MOND.

Milgrom, Mordehai

2012-09-01

347

Predicting in-service fatigue life of flexible pavements based on accelerated pavement testing  

NASA Astrophysics Data System (ADS)

Pavement performance prediction in terms of fatigue cracking and surface rutting are essential for any mechanistically-based pavement design method. Traditionally, the estimation of the expected fatigue field performance has been based on the laboratory bending beam test. Full-scale Accelerated Pavement Testing (APT) is an alternative to laboratory testing leading to advances in practice and economic savings for the evaluation of new pavement configurations, stress level related factors, new materials and design improvements. This type of testing closely simulates field conditions; however, it does not capture actual performance because of the limited ability to address long-term phenomena. The same pavement structure may exhibit different response and performance under APT than when in-service. Actual field performance is better captured by experiments such as Federal Highway Administration's Long-Term Pavement Performance (LTPP) studies. Therefore, to fully utilize the benefits of APT, there is a need for a methodology to predict the long-term performance of in-service pavement structures from the results of APT tests that will account for such differences. Three models are generally suggested to account for the difference: shift factors, statistical and mechanistic approaches. A reliability based methodology for fatigue cracking prediction is proposed in this research, through which the three models suggested previously are combined into one general approach that builds on their individual strengths to overcome some of the shortcomings when the models are applied individually. The Bias Correction Factor (BCF) should account for all quantifiable differences between the fatigue life of the pavement site under APT and in-service conditions. In addition to the Bias Correction Factor, a marginal shifty factor, M, should be included to account for the unquantifiable differences when predicting the in-service pavement fatigue life from APT. The Bias Correction Factor represents an improvement of the currently used "shift factors" since they are more general and based on laboratory testing or computer simulation. By applying the proposed methodology, APT performance results from a structure similar to an in-service structure can be used to perform four-point bending beam tests and structural analysis to obtain an accurate estimate of the necessary Bias Correction Factor to estimate in-service performance.

Guo, Runhua

348

The Prediction of Shelf-Storage Life in Rubbers from Accelerated Heat Ageing Tests. Part I. Accelerated Oven Ageing.  

National Technical Information Service (NTIS)

Oven ageing experiments in which the mechanical tests are performed at the temperature of ageing have been carried out on Nitrile, Neoprene, and Hypalon rubbers. In all cases the variation of one or more of the mechanical properties with time at a series ...

D. K. Thomas R. Sinnott J. Day

1967-01-01

349

Tested by Fire - How two recent Wildfires affected Accelerator Operations at LANL  

SciTech Connect

In a little more than a decade two large wild fires threatened Los Alamos and impacted accelerator operations at LANL. In 2000 the Cerro Grande Fire destroyed hundreds of homes, as well as structures and equipment at the DARHT facility. The DARHT accelerators were safe in a fire-proof building. In 2011 the Las Conchas Fire burned about 630 square kilometers (250 square miles) and came dangerously close to Los Alamos/LANL. LANSCE accelerator operations Lessons Learned during Las Conchas fire: (1) Develop a plan to efficiently shut down the accelerator on short notice; (2) Establish clear lines of communication in emergency situations; and (3) Plan recovery and keep squirrels out.

Spickermann, Thomas [Los Alamos National Laboratory

2012-08-01

350

Accelerated aging, natural aging, and small punch testing of gamma-air sterilized polycarbonate urethane acetabular components.  

PubMed

The objectives of this study were three-fold: (1) to determine the applicability of the small punch test to characterize Bionate 80A polycarbonate urethane (PCU) acetabular implants; (2) to evaluate the susceptibility of PCU acetabular implants to exhibit degradation of mechanical behavior following gamma irradiation in air and accelerated aging; and (3) to compare the oxidation of gamma-air sterilized PCU following accelerated aging and 5 years of natural shelf aging. In addition to attenuated total reflectance-Fourier transform infrared spectroscopy, we also adapted a miniature specimen mechanical test, the small punch test, for the deformable PCU cups. Accelerated aging was performed using ASTM F2003, a standard test that represents a severe oxidative challenge. The results of this study suggest that the small punch test is sufficiently sensitive and reproducible to discriminate slight differences in the large-deformation mechanical behavior of Bionate 80A following accelerated aging. The gamma-air sterilized PCU had a reduction of 9% in ultimate load after aging. Five years of shelf aging had little effect on the mechanical properties of the PCU. Overall, our findings suggest that the Bionate 80A material has greater oxidative stability than ultra-high molecular weight polyethylene following gamma irradiation in air and exposure to a severe oxidative challenge. PMID:20166119

Kurtz, S M; Siskey, R; Reitman, M

2010-05-01

351

Corrosion Testing in Support of the Accelerator Production of Tritium Program  

SciTech Connect

The Accelerator Production of Tritium Project is part of the United States Department of Energy strategy to meet the nation's tritium needs. The project involves the design of a proton beam accelerator, which will produce tritium through neutron/proton interaction with helium-3. Design, construction and operation of this one-of-a-kind facility will involve the utilization of a wide variety of materials exposed to unique conditions, including elevated temperature and high-energy mixed-proton and -neutron spectra. A comprehensive materials test program was established by the APT project which includes the irradiation of structural materials by exposure to high-energy protons and neutrons at the Los Alamos Neutron Science Center at the Los Alamos National Laboratory. Real-time corrosion measurements were performed on specially designed corrosion probes in water irradiated by an 800 MeV proton beam. The water test system provided a means for measuring water chemistry, dissolved hydroge n concentration, and the effects of water radiolysis and water quality on corrosion rate. The corrosion probes were constructed of candidate APT materials alloy 718, 316L stainless steel, 304L stainless steel, and 6061 Aluminum (T6 heat treatment), and alternate materials 5052 aluminum alloy, alloy 625, and C276. Real-time corrosion rates during proton irradiation increased with proton beam current. Efforts are continuing to determine the effect of proton beam characteristics and mixed-particle flux on the corrosion rate of materials located directly in the proton beam. This paper focuses on the real-time corrosion measurements of materials located in the supply stream and return stream of the water flow line to evaluate effects of long-lived radiolysis products and water chemistry on the corrosion rates of materials. In general, the corrosion rates for the out-of-beam probes were low and were affected mainly by water conductivity. The data indicate a water conductivity threshold e xists to minimize corrosion in the out-of-beam areas, especially for aluminum. The in-beam probes also revealed a water conductivity threshold but at a lower value compared to the out-of-beam probes.

Chandler, G.

2000-11-07

352

Geogrid mechanism in low-volume flexible pavements: accelerated testing of full-scale heavily instrumented pavement sections  

Microsoft Academic Search

This study uses full-scale accelerated testing to provide new insight into the effectiveness of geogrids on the performance of low-volume flexible pavements. Although several previous studies reported that geogrids improve pavement performance by enhancing its structural capacity and reducing distress potential, this study goes further to quantify the effectiveness of geogrids, specify the mechanism of the reinforcement they provide and

Imad L. Al-Qadi; Samer Dessouky; Erol Tutumluer; Jayhyun Kwon

2011-01-01

353

Aircraft Thermal Management Using Loop Heat Pipes: Experimental Simulation of High Acceleration Environments Using the Centrifuge Table Test Bed (Postprint).  

National Technical Information Service (NTIS)

The objective of this paper is to describe the design of an experiment that will examine the effects of elevated acceleration environments on a high-temperature, titanium-water loop heat pipe for actuator cooling. An experimental test setup has been desig...

A. J. Fleming K. L. Yerkes L. J. Elston Q. H. Leland S. K. Thomas

2006-01-01

354

Accelerated life test sampling plans for the Weibull distribution under Type I progressive interval censoring with random removals  

Microsoft Academic Search

This paper considers the design of accelerated life test (ALT) sampling plans under Type I progressive interval censoring with random removals. We assume that the lifetime of products follows a Weibull distribution. Two levels of constant stress higher than the use condition are used. The sample size and the acceptability constant that satisfy given levels of producer's risk and consumer's

Chang Ding; Chunyan Yang; Siu-Keung Tse

2010-01-01

355

Accelerated thermal cycle test of acetamide, stearic acid and paraffin wax for solar thermal latent heat storage applications  

Microsoft Academic Search

1500 accelerated thermal cycle tests have been conducted to study the changes in latent heat of fusion and melting temperature of commercial grade acetamide, stearic acid and paraffin wax. It has been noticed that the stearic acid melts over a wide range of temperature, has shown two melting points and has large variations in latent heat of fusion. Paraffin wax

Atul Sharma; S. D Sharma; D Buddhi

2002-01-01

356

Application of a relational data base for documenting the Ground Test Accelerator cable routing and wiring interconnections  

Microsoft Academic Search

The Ground Test Accelerator (GTA) has many different types of equipment and interconnections to support the operation. Various functions are performed by these equipments such as signal generation, instrument control, and diagnostics. All of the thousands of signals must be routed from the protected tunnel area into the operational control area of the building. Tabulating the routing of these cables,

D. B. Blackwell; W. L. Rogers; V. W. Brown; G. A. Ekeroth; T. O. McGill

1990-01-01

357

Development of an accelerated test design for predicting the service life of the solar array at Mead, Nebraska. Quarterly report  

SciTech Connect

Economic viability requires that photovoltaic arrays should have a service life of 20 years or longer. Qualification and performance tests indicate that presently available photovoltaic modules provide acceptable performance at the time of installation. This study is being conducted as part of a program to develop and validate an accelerated test plan that can be used to predict the useful service life of present and future solar arrays. Previously a methodology was developed for designing an accelerated test program incorporating trade-offs between the cost of each test and its value in reducing the variance in the life prediction for that array. The objective of the present study is to apply this methodology to develop an accelerated test plan to predict the service life of the 25-kW photovoltaic array installed near Mead, Nebraska. Potential long-term degradation modes for the two types of modules in the Mead array have been determined and judgments have been made as to those environmental stresses and combinations of stresses which accelerate the degradation of the power output. Hierarchical trees representing the severity of effects of stresses (test conditions) on eleven individual degradation modes have been constructed and have been pruned of tests judged to be nonessential. Composites of those trees have been developed so that there is now one pruned tree covering eight degradation modes, another covering two degradation modes, and a third covering one degradation mode. These three composite trees form the basis for selection of test conditions in the final test plan which is now being prepared.

Gaines, G.B.; Thomas, R.E.; Noel, G.T.; Shilliday, T.S.; Wood, V.E.; Carmichael, D.C.

1979-02-06

358

Electron Cloud Effects in Cornell Electron Storage Ring Test Accelerator and International Linear Collider Damping Ring  

NASA Astrophysics Data System (ADS)

In this paper, the effects of electron cloud are discussed for the ultra low emittance positron beam in Cornell Electron Storage Ring Test Accelerator (Cesr-TA) and the International Linear Collider (ILC) damping ring. We have investigated the electron-cloud instabilities with Cesr-TA which has been operating to experiment for the ILC damping ring with different positron beam energies: 2 and 5 GeV. The electron phase factor, ?e,y?z/c, is given differently to each case. The single-bunch instability is investigated with a simulation based on the strong-strong model by using the simplified lattice. The threshold densities obtained by simulations agree with the predicted values within a factor 1.3. We investigate the effects of the bunch-by-bunch feedback of about 50 turns and non-zero dispersion. The simulation results show that the feedback system suppresses the dipole motion and increases the threshold density in 2 GeV case, but is less effective in 5 GeV case. The threshold densities are degraded with non-zero dispersion in both cases, but the rates of degradation appear differently. We discuss an incoherent emittance growth using the realistic lattice model for Cesr-TA. Below the threshold, the incoherent emittance growth may not be serious in Cesr-TA and the ILC damping ring.

Jin, Hyunchang; Yoon, Moohyun; Ohmi, Kazuhito; Flanagan, John W.; Palmer, Mark A.

2011-02-01

359

Utilization of optical image data from the Advanced Test Accelerator (ATA)  

SciTech Connect

Extensive use is made of optical diagnostics to obtain information on the 50-MeV, 10-kA, 70-ns pulsed-electron beam produced by the Advanced Test Accelerator (ATA). Light is generated by the beam striking a foil inserted in the beamline or through excitation of the gas when the beamline is filled with air. The emitted light is collected and digitized. Two-dimensional images are recorded by either a gated framing camera or a streak camera. Extraction of relevant beam parameters, such as current density, current, and beam size, requires an understanding of the physics of the light-generation mechanism and an ability to handle and properly exploit a large digital database of image data. We will present a brief overview of the present understanding of the light-generation mechanisms in foil and gas, with emphasis on experimental observations and trends. We will review our data management and analysis techniques and indicate successful approaches for extracting beam parameters.

Chambers, F.W.; Kallman, J.S.; Slominski, M.E.; Chong, Y.P.; Donnelly, D.; Cornish, J.P.

1987-01-01

360

Accelerator production of tritium 700 MHz and 350 MHz klystron test results  

SciTech Connect

The Accelerator Production of Tritium project (APT) utilizes a 1,700 MeV, 100 mA proton Linac. The radio frequency (RF) power is provided by 244 continuous wave (CW) klystron amplifiers at 350 MHz and 700 MHz. All but three of the klystrons operate at a frequency of 700 MHz. The 350 MHz klystrons have a nominal output power of 1.2 MW at a DC-to-RF conversion efficiency of 65%. They are modulating-anode klystrons and operate at a beam voltage and current of 95 kV and 20 A. The design is based on the CERN klystron. The 700 MHz klystron is a new development for APT. Three 700 MHz klystrons are currently under development. Two vendors are each developing a baseline klystron that has a nominal output power of 1.0 MW at a DC-to-RF conversion efficiency of 65%. A 700 MHz klystron is also under development that promises to provide an efficiency in excess of 70%. The 700 MHz klystrons operate at a maximum beam voltage of 95 kV and a maximum beam current of 17 A. The test results of these klystrons will be presented and the design features will be discussed.

Rees, D.; Lynch, M.; Tallerico, P.

1998-12-31

361

ATTO SECOND ELECTRON BEAMS GENERATION AND CHARACTERIZATION EXPERIMENT AT THE ACCELERATOR TEST FACILITY.  

SciTech Connect

We are proposing an Atto-second electron beam generation and diagnostics experiment at the Brookhaven Accelerator Test facility (ATF) using 1 {micro}m Inverse Free Electron Laser (IFEL). The proposed experiment will be carried out by an BNL/LBNL collaboration, and it will be installed at the ATF beam line II. The proposed experiment will employ a one-meter long undulator with 1.8 cm period (VISA undulator). The electron beam energy will be 63 MeV with emittance less than 2 mm-mrad and energy spread less than 0.05%. The ATF photocathode injector driving laser will be used for energy modulation by Inverse Free Electron Laser (IFEL). With 10 MW laser peak power, about 2% total energy modulation is expected. The energy modulated electron beam will be further bunched through either a drift space or a three magnet chicane into atto-second electron bunches. The attosecond electron beam bunches will be analyzed using the coherent transition radiation (CTR).

ZOLOTOREV, M.; ZHOLENTS, A.; WANG, X.J.; BABZIEN, M.; SKARITKA, J.; RAKOWSKY, G.; YAKIMENKO, V.

2002-02-01

362

Fabrication and testing of Rutherford-type cables for react and wind accelerator magnets  

SciTech Connect

A common coil design for a high-field accelerator dipole magnet using a Nb{sub 3}Sn cable with the React-and-Wind approach is pursued by a collaboration between Fermilab and LBNL. The design requirements for the cable include a high operating current so that a field of 10-11 T can be produced, together with a low critical current degradation due to bending around a 90 mm radius. A program, using ITER strands of the internal tin type, was launched to develop the optimal cable design for React-and-Wind common coil magnets. Three prototype cable designs, all 15 mill wide, were fabricated: a 41-strand cable with 0.7 mm diameter strands; a 57-strand cable with 0.5 mm diameter strands; and a 259 strand multi-level cable with a 6-around-1 sub-element using 0.3 mm diameter wire. Two versions of these cables were fabricated: one with no core and one with a stainless steel core. Additionally, the possibility of a wide (22 mm) cable made from 0.7 mm strand was explored. This paper describes the first results of the cable program including reports on cable fabrication and reaction, first winding tests and first results of the measurement of the critical current degradation due to cabling and bending.

Bauer, P.; Ambrosio, G.; Andreev, N.; Barzi, E.; Dietderich, D.; Ewald, K.; Fratini, M.; Ghosh, A.K.; Higley, H.C.; Kim, S.W.; Miller, G.; Miller, J.; Ozelis, J.; Scanlan, R.M.

2000-09-11

363

Intrabeam scattering analysis of measurements at KEK's Accelerator Test Facility damping ring  

NASA Astrophysics Data System (ADS)

We derive a simple relation for estimating the relative emittance growth in x and y due to intrabeam scattering (IBS) in electron storage rings. We show that IBS calculations for the Accelerator Test Facility (ATF) damping ring, when using the formalism of Bjorken-Mtingwa, a modified formalism of Piwinski (where ?2/? has been replaced by H), or a simple high-energy approximate formula all give results that agree well. Comparing theory, including the effect of potential well bunch lengthening, with a complete set of ATF steady-state beam size versus current measurements we find reasonably good agreement for energy spread and horizontal emittance. The measured vertical emittance, however, is larger than theory in both offset (zero current emittance) and slope (emittance change with current). Almost all the offset error can be accounted for by considering the expected projected vertical emittance due to machine errors rather than the real emittance. This result is consistent with the assumed Coulomb log factor being close to the correct one. The slope error indicates measurement error and/or additional current-dependent physics at the ATF.

Bane, K. L.; Hayano, H.; Kubo, K.; Naito, T.; Okugi, T.; Urakawa, J.

2002-08-01

364

Structural Integrity, Accelerated Corrosion and Flow Capacity Tests of Parker Aircraft Company Valve, Check, One-Inch, Airborne, Fuel Parker Part Number 2630014. Gd/a Part Number 27-02402-5.  

National Technical Information Service (NTIS)

Two units were submitted for testing. The test program consisted of diameter measurements, accelerated corrosion, flow capacity and burst pressure tests. A 30-day accelerated corrosion test caused severe corrosion of the body base metal; but, there was no...

1964-01-01

365

Automated-process gas-chromatograph system for use in accelerated corrosion testing of HTGR core-support posts  

Microsoft Academic Search

An automated-process gas chromatograph is the heart of a gaseous-impurities-analysis system developed for the Oak Ridge National Laboratory Core Support Performance Test, at which graphite core-support posts for high-temperature gas-cooled fission reactors are being subjected to accelerated corrosion tests under tightly controlled conditions of atmosphere and temperature. Realistic estimation of in-core corrosion rates is critically dependent upon the accurate measurement

R. E. Harper; P. G. Herndon

1982-01-01

366

Using a commercial mathematics software package for on-line analysis at the BNL Accelerator Test Facility  

SciTech Connect

BY WRITING BOTH A CUSTOM WINDOWS(NTTM) DYNAMIC LINK LIBRARY AND GENERIC COMPANION SERVER SOFTWARE, THE INTRINSIC FUNCTIONS OF MATHSOFT MATHCAD(TM) HAVE BEEN EXTENDED WITH NEW CAPABILITIES WHICH PERMIT DIRECT ACCESS TO THE CONTROL SYSTEM DATABASES OF BROOKHAVEN NATIONAL LABORATORY ACCELERATOR TEST FACILITY. UNDER THIS SCHEME, A MATHCAD WORKSHEET EXECUTING ON A PERSONAL COMPUTER BECOMES A CLIENT WHICH CAN BOTH IMPORT AND EXPORT DATA TO A CONTROL SYSTEM SERVER VIA A NETWORK STREAM SOCKET CONNECTION. THE RESULT IS AN ALTERNATIVE, MATHEMATICALLY ORIENTED VIEW OF CONTROLLING THE ACCELERATOR INTERACTIVELY.

Malone, R.; Wang, X.J.

1999-06-14

367

Observation and Characterization of Coherent Optical Radiation and Microbunching Instability in the SLAC Next Linear Collider Test Accelerator  

SciTech Connect

The NLC Test Accelerator (NLCTA) at SLAC is currently configured for a proof-of-principle echo-enabled harmonic generation (EEHG) experiment using an 120 MeV beam. During commissioning, unexpected coherent optical undulator radiation (CUR) and coherent optical transition radiation (COTR) was observed when beam is accelerated off-crest and compressed after the chicanes. The CUR and COTR is likely due to a microbunching instability where the initial small ripples in cathode drive laser is compressed and amplified. In this paper we present the observation and characterization of the CUR, COTR and microbunching instability at NLCTA.

Weathersby, S.; Dunning, M.; Hast, C.; Jobe, K.; McCormick, D.; Nelson, J.; Xiang, D.; /SLAC

2011-06-02

368

Polarization Losses under Accelerated Stress Test Using Multiwalled Carbon Nanotube Supported Pt Catalyst in PEM Fuel Cells  

SciTech Connect

The electrochemical behavior for Pt catalysts supported on multiwalled carbon nanotubes and Vulcan XC-72 in proton exchange membrane fuel cells under accelerated stress test was examined by cyclic voltammetry, electrochemical impedance spectroscopy, and polarization technique. Pt catalyst supported on multiwalled carbon nanotubes exhibited highly stable electrochemical surface area, oxygen reduction kinetics, and fuel cell performance at a highly oxidizing condition, indicating multiwalled carbon nanotubes show high corrosion resistance and strong interaction with Pt nanoparticles. The Tafel slope, ohmic resistances, and limiting current density determined were used to differentiate kinetic, ohmic, mass-transfer polarization losses from the actual polarization curve. Kinetic contribution to the total overpotential was larger throughout the stress test. However, the fraction of kinetic overpotential decreased and mass-transfer overpotential portion remained quite constant during accelerated stress test, whereas the fraction of ohmic overpotential primarily originating from severe proton transport limitation in the catalyst layer increased under the anodic potential hold.

Park, Seh K.; Shao, Yuyan; Kou, Rong; Viswanathan, Vilayanur V.; Towne, Silas A.; Rieke, Peter C.; Liu, Jun; Lin, Yuehe; Wang, Yong

2011-03-01

369

Analysis of Light-Induced Degradation in Amorphous Silicon Alloy Solar Cells and Its Application to Accelerated Test Method  

NASA Astrophysics Data System (ADS)

Light-induced degradation in amorphous silicon alloy single-junction solar cells has been studied systematically. The dependence of the light-induced degradation in the conversion efficiency and the other photovoltaic parameters on light intensity and bias voltage has been clarified quantitatively. It has been shown that the light-induced degradation characteristics of the photovoltaic parameters can be described by a single function of certain normalized parameters of the exposure condition. Theoretical background for the experimental results has been clarified by applying a defect creation model modified to the a-Si alloy solar cells. Moreover, using the above single function, we have proposed a new accelerated test method by indoor measurement under the solar simulator instead of outdoor testing under natural sunlight. The validity of the accelerated test method has been confirmed experimentally.

Nakata, Yukihiko; Yokota, Akitoshi; Sannomiya, Hitoshi; Moriuchi, Sohta; Inoue, Yasumi; Nomoto, Katsuhiko; Itoh, Manabu; Tsuji, Takateru

1992-02-01

370

Development, test and large production of soft switching high current power converters for particle accelerators  

Microsoft Academic Search

The large hadron collider (LHC) is the next particle accelerator being constructed on the CERN site. The 27 km long accelerator requires many high current (multi-kA) power converters to supply the superconducting magnets. This paper describes the development of a modular high current power converter, capable of supplying up to [8 kA, 8 V] using several current sources of [2

F. Bordry; V. Montabonnet; D. Nisbet; P. Korhonen; R. Turunen; H. Volotinen

2005-01-01

371

Experimental test of a new antiproton acceleration scheme in the Fermilab Main Injector  

SciTech Connect

In an effort to provide higher intensity and lower emittance antiproton beam to the Tevatron collider for high luminosity operation, a new Main Injector (MI) antiproton acceleration scheme has been developed [1-4]. In this scheme, beam is accelerated from 8 to 27 GeV using the 2.5 MHz rf system and from 27 to 150 GeV using the 53 MHz rf system. This paper reports the experimental results of beam study. Simulation results are reported in a different PAC'05 paper [5]. Experiments are conducted with proton beam from the Booster. Acceleration efficiency, emittance growth and beam harmonic transfer between 2.5 MHz (h=28) and 53 MHz (h=588) buckets have been studied. Beam study shows that one can achieve an overall acceleration efficiency of about 100%, longitudinal emittance growth less than 20% and negligible transverse emittance growth. accelerated to 150 GeV and injected to the Tevatron. The multi-bunch coalescing process is eliminated in this acceleration scheme. Consequently, longitudinal emittance growth is reduced. Smaller emittance growth reduces beam loss.

Wu, V.; Bhat, C.M.; Chase, B.E.; Dey, J.E.; Meisner, K.G.; /Fermilab

2005-05-01

372

Testing the accelerating moment release (AMR) hypothesis in areas of high stress  

NASA Astrophysics Data System (ADS)

Several retrospective analyses have proposed that significant increases in moment release occurred prior to many large earthquakes of recent times. However, the finding of accelerating moment release (AMR) strongly depends on the choice of three parameters: (1) magnitude range, (2) area being considered surrounding the events and (3) the time period prior to the large earthquakes. Consequently, the AMR analysis has been criticized as being a posteriori data-fitting exercise with no new predictive power. As AMR has been hypothesized to relate to changes in the state of stress around the eventual epicentre, we compare here AMR results to models of stress accumulation in California. Instead of assuming a complete stress drop on all surrounding fault segments implied by a back-slip stress lobe method, we consider that stress evolves dynamically, punctuated by the occurrence of earthquakes, and governed by the elastic and viscous properties of the lithosphere. We study the seismicity of southern California and extract events for AMR calculations following the systematic approach employed in previous studies. We present several sensitivity tests of the method, as well as grid-search analyses over the region between 1955 and 2005 using fixed magnitude range, radius of the search area and period of time. The results are compared to the occurrence of large events and to maps of Coulomb stress changes. The Coulomb stress maps are compiled using the coseismic stress from all M > 7.0 earthquakes since 1812, their subsequent post-seismic relaxation, and the interseismic strain accumulation. We find no convincing correlation of seismicity rate changes in recent decades with areas of high stress that would support the AMR hypothesis. Furthermore, this indicates limited utility for practical earthquake hazard analysis in southern California, and possibly other regions.

Guilhem, Aurlie; Brgmann, Roland; Freed, Andrew M.; Ali, Syed Tabrez

2013-08-01

373

Testing the accelerating moment release (AMR) hypothesis in areas of high stress  

NASA Astrophysics Data System (ADS)

Several retrospective analyses have proposed that significant increases in moment release occurred prior to many large earthquakes of recent times. However, the finding of accelerating moment release (AMR) strongly depends on the choice of three parameters: (1) magnitude range, (2) area being considered surrounding the events and (3) the time period prior to the large earthquakes. Consequently, the AMR analysis has been criticized as being a posteriori data-fitting exercise with no new predictive power. As AMR has been hypothesized to relate to changes in the state of stress around the eventual epicentre, we compare here AMR results to models of stress accumulation in California. Instead of assuming a complete stress drop on all surrounding fault segments implied by a back-slip stress lobe method, we consider that stress evolves dynamically, punctuated by the occurrence of earthquakes, and governed by the elastic and viscous properties of the lithosphere. We study the seismicity of southern California and extract events for AMR calculations following the systematic approach employed in previous studies. We present several sensitivity tests of the method, as well as grid-search analyses over the region between 1955 and 2005 using fixed magnitude range, radius of the search area and period of time. The results are compared to the occurrence of large events and to maps of Coulomb stress changes. The Coulomb stress maps are compiled using the coseismic stress from all M > 7.0 earthquakes since 1812, their subsequent post-seismic relaxation, and the interseismic strain accumulation. We find no convincing correlation of seismicity rate changes in recent decades with areas of high stress that would support the AMR hypothesis. Furthermore, this indicates limited utility for practical earthquake hazard analysis in southern California, and possibly other regions.

Guilhem, Aurlie; Brgmann, Roland; Freed, Andrew M.; Ali, Syed Tabrez

2013-11-01

374

Accelerated Reader.  

ERIC Educational Resources Information Center

|This paper provides an overview of Accelerated Reader, a system of computerized testing and record-keeping that supplements the regular classroom reading program. Accelerated Reader's primary goal is to increase literature-based reading practice. The program offers a computer-aided reading comprehension and management program intended to motivate

Education Commission of the States, Denver, CO.

375

Advanced test accelerator (ATA), a 50 MeV, 10 kA induction linac  

SciTech Connect

The ATA is an induction accelerator designed to produce 70 ns pulses of electrons at currents of 10 kA and energies in excess of 50 MeV. The accelerator is capable of operating at an average rate of 5 Hz or at 1 kHz for ten pulses. The parameters were chosen primarily to provide the experimental basis for advancing the understanding of electron beam propagation physics. The 85 m accelerator has been under construction for the past four years and has adopted mainly an improved version of the ETA technology to satisfy the required parameters. Initial operation of the facility and the energy conversion system from primary power to axial electric field will be described; recent advances in magnetic switching which have been incorporated in the innector will also be discussed.

Reginato, L.

1983-01-01

376

Combined approach to damaged wire ropes life-time assessment based on NDT results and rope mechanics  

NASA Astrophysics Data System (ADS)

Principles of strength assessment and life-time prediction of deteriorated wire ropes based on magnetic NDT technique are presented. The measured loss of metallic cross-section area due to abrasion, corrosion etc. and local wire breaks are treated as input data for mechanical model of rope structure. The rope is interpreted as a system with two degrees of freedom that enables to calculate the strains and stresses in each wire when the rope is subjected to tension, torsion and bending. Stress safety factor is considered as a generalized parameter that specifies the rope degradation and may be used for predicting the instant lifetimes during the rope operating history. The rope discard criterion refers to residual life-time calculated with respect to minimal allowable strength factor. Examples of integrity analysis of mine hoisting rope and jib crane rope under tension-bending fatigue loading are demonstrated. The residual strength estimates give the rope inspector further information that helps to make a valid decision on testing policy.

Vorontsov, A.; Volokhovsky, V.; Slesarev, D.

2011-07-01

377

Muon capture in {sup 40}Ar. Muon life-time and isotope yields  

SciTech Connect

Time and energy spectra of gamma-rays following muon capture in {sup 40}Ar were measured. Muon life-time in {sup 40}Ar and isotope yields ({sup 38}Cl,{sup 39}Cl,{sup 40}Cl,{sup 38}S,{sup 39}S) are presented.

Klinskih, A.; Egorov, V.; Shirchenko, M.; Zinatulina, D. [Joint Institute for Nuclear Research Dubna 141980 (Russian Federation)

2007-10-12

378

Long-Term and Accelerated Life Testing of a Novel Single-Wafer Vacuum Encapsulation for MEMS Resonators  

Microsoft Academic Search

We have developed a single-wafer vacuum encapsulation for microelectromechanical systems (MEMS), using a thick (20-mum) polysilicon encapsulation to package micromechanical resonators in a pressure 600 cycles of -50 to 80degC, and no measurable change in cavity pressure was seen. We have also performed accelerated leakage tests by driving hydrogen gas in and out of the encapsulation at elevated temperature. Two

Rob N. Candler; Matthew A. Hopcroft; Bongsang Kim; Woo-Tae Park; Renata Melamud; Manu Agarwal; Gary Yama; Aaron Partridge; Markus Lutz; Thomas W. Kenny

2006-01-01

379

An investigation of piston ring groove wear in heavy duty diesel engines using statistically designed accelerated testing  

Microsoft Academic Search

An interdisciplinary approach was taken to investigate the wear phenomenon occurring in the piston s aluminum second ring\\u000a groove in heavy duty diesel engines. The wear mechanisms and aggravating engine conditions were identified; this information\\u000a was used to develop an accelerated engine test that duplicated field incidents. A fractional factorial experiment was designed\\u000a to investigate the effect that various piston

R. Krivoy; J. K. Colvill; D. H. Parsons

1986-01-01

380

Accelerated caffeine metabolism after omeprazole treatment is indicated by urinary metabolite ratios: Coincidence with plasma clearance and breath test  

Microsoft Academic Search

Background: Omeprazole has previously been shown to induce hepatic cytochrome P4501A2 activity, as evidenced by an accelerated N-3-demethylation in the 13C-[N-3-methyl]-caffeine breath test. In this study we investigated whether the inducing potency of omeprazole can be quantified by the determination of urinary caffeine metabolite ratios, which are based on the urinary excretion of N-3-demethylated metabolites. These data were also compared

Karl Ludwig Rost; Ivar Roots

1994-01-01

381

Effect of various coal contaminants on the performance of solid oxide fuel cells: Part I. Accelerated testing  

Microsoft Academic Search

The contaminants that are potentially present in the coal-derived gas stream and their thermochemical nature are discussed. Accelerated testing was carried out on NiYSZ\\/YSZ\\/LSM solid oxide fuel cells (YSZ: yttria stabilized zirconia and LSM: lanthanum strontium manganese oxide) for eight main kind of contaminants: CH3Cl, HCl, As, P, Zn, Hg, Cd and Sb at the temperature range of 750850C. The

JianEr Bao; Gopala N. Krishnan; Palitha Jayaweera; Jordi Perez-Mariano; Angel Sanjurjo

2009-01-01

382

Analysis of DC current accelerated life tests of GaN LEDs using a Weibull-based statistical model  

Microsoft Academic Search

Gallium-nitride-based light-emitting diode (LED) accelerated life tests were carried out over devices adopting two different packaging schemes (i.e., with plastic transparent encapsulation or with pure metallic package). Data analyses were done using a Weibull-based statistical description with the aim of estimating the effect of high current on device performance. A consistent statistical model was found with the capability to estimate

S. Levada; M. Meneghini; G. Meneghesso; E. Zanoni

2005-01-01

383

10-GW CO2 laser system at the Brookhaven Accelerator Test Facility.  

National Technical Information Service (NTIS)

Design and performance of a high peak-power CO(sub 2) laser system to produce subnanosecond IR pulses for electron acceleration experiment are presented. We discuss theoretical aspects of the picosecond laser pulse propagation in a molecular amplifier and...

I. Pogorelsky J. Fischer A. S. Fisher

1993-01-01

384

10GW CO2 laser system at the Brookhaven Accelerator Test Facility  

Microsoft Academic Search

Design and performance of a high peak-power CO2 laser system to produce subnanosecond IR pulses for electron acceleration experiment are presented. We discuss theoretical aspects of the picosecond laser pulse propagation in a molecular amplifier and a design approach towards compact Terawatt CO2 laser systems.

I. Pogorelsky; J. Fischer; A. S. Fisher

1993-01-01

385

KA-BAND TEST FACILITY FOR HIGH GRADIENT ACCELERATOR R&D  

Microsoft Academic Search

Achievement of high acceleration gradients in room- temperature structures requires basic studies of electrical and magnetic RF field limits at surfaces of conductors and dielectrics. Facilities for such studies at 11.4 GHz have been in use at KEK and SLAC; facilities for studies at 17.1 GHz are being developed at MIT and UMd; and studies at 30 GHz are being

M. A. LaPointe; A. A. Bogdashov; A. B. Chirkov; G. G. Denisov; J. L. Hirshfield; E. V. Kozyrev; S. V. Kuzikov; A. G. Litvak; D. A. Lukovnikov; V. I. Malygin; O. A. Nezhevenko; Yu. V. Rodin; G. V. Serdobintsev; S. V. Shchelkunov; M. Y. Shmelyov; M. I. Petelin; A. L. Vikharev; V. P. Yakovlev; BINP SB RAS; RAS Nizhny Novgorod

2006-01-01

386

Data acquisition, control, and analysis for the Argonne Advanced Accelerator Test Facility (AATF)  

SciTech Connect

The AATF has been used to study wakefield acceleration and focusing in plasmas and rf structures. A PC-based system is described which incorporates the functions of beamline control and acquisition, storage, and preliminary analysis of video images from luminescent screen beam diagnostics. General features of the offline analysis of wakefield data are also discussed. 4 refs., 3 figs.

Schoessow, P.

1989-01-01

387

10-GW CO{sub 2} laser system at the Brookhaven Accelerator Test Facility  

SciTech Connect

Design and performance of a high peak-power CO{sub 2} laser system to produce subnanosecond IR pulses for electron acceleration experiment are presented. We discuss theoretical aspects of the picosecond laser pulse propagation in a molecular amplifier and a design approach towards compact Terawatt CO{sub 2} laser systems.

Pogorelsky, I.; Fischer, J.; Fisher, A.S. [and others

1993-12-31

388

Design study of prototype accelerator and MeV test facility for demonstration of 1 MeV, 1 A negative ion beam production  

NASA Astrophysics Data System (ADS)

In fusion reactors such as ITER, a neutral beam injector of MeV class beam energy and several tens MW class power is required as one of candidates of heating and current drive systems. However, the beam energy of existing high power accelerators are one order of magnitude lower than the required value. In order to realize a neutral beam injector for the fusion reactor, 'Proof-of-Principle' of such high energy acceleration is a critical issue at a reactor relevant beam current and pulse length. An accelerator and an accelerator facility which are necessary to demonstrate the Proof-of-Principle acceleration of negative ion beams up to 1 MeV, have been designed in the present study. The accelerator is composed of a cesium-volume type ion source and a multi-stage electrostatic acceleration system 'Prototype Accelerator'. A negative hydrogen ion beam with the current of about one ampere (1 A) can be accelerated up to 1 MeV at a low operating pressure. Two types of acceleration systems, a multi-multi type and a multi-single type, have been studied. The test facility has sufficient capability for the test of the Prototype Accelerator (MeV Test Facility). The dc high voltage generator for negative ion acceleration is a Cockcroft-Walton type and capable of delivering 1 A at 1 MV (=1 MW) for 60 s. High voltage components including Prototype Accelerator are installed in a SF(sub 6) vessel pressurized at 6 kg/cm(exp 2) to overcome high voltage gradients. The vessel and the beamline are installed in a X-ray shield.

Inoue, Takashi; Hanada, Masaya; Miyamoto, Kenji; Ohara, Yoshihiro; Okumura, Yoshikazu; Watanabe, Kazuhiro; Maeno, Shuichi

1994-08-01

389

Cavity digital control testing system by Simulink step operation method for TESLA linear accelerator and free electron laser  

NASA Astrophysics Data System (ADS)

The cavity control system for the TESLA -- TeV-Energy Superconducting Linear Accelerator project is initially introduced in this paper. The FPGA -- Field Programmable Gate Array technology has been implemented for digital controller stabilizing cavity field gradient. The cavity SIMULINK model has been applied to test the hardware controller. The step operation method has been developed for testing the FPGA device coupled to the SIMULINK model of the analog real plant. The FPGA signal processing has been verified according to the required algorithm of the reference MATLAB controller. Some experimental results have been presented for different cavity operational conditions.

Czarski, Tomasz; Romaniuk, Ryszard S.; Pozniak, Krzysztof T.; Simrock, Stefan

2004-07-01

390

Evaluation of accelerated UV and thermal testing for benzene formation in beverages containing benzoate and ascorbic acid.  

PubMed

Under certain conditions, benzene can form in beverages containing benzoic and ascorbic acids. The American Beverage Assn. (ABA) has published guidelines to help manufacturers mitigate benzene formation in beverages. These guidelines recommend accelerated testing conditions to test product formulations, because exposure to ultraviolet (UV) light and elevated temperature over the shelf life of the beverage may result in benzene formation in products containing benzoic and ascorbic acids. In this study, the effects of UVA exposure on benzene formation were determined. Benzene formation was examined for samples contained in UV stabilized and non-UV stabilized packaging. Additionally, the usefulness of accelerated thermal testing to simulate end of shelf-life benzene formation was evaluated for samples containing either benzoic or ascorbic acid, or both. The 24 h studies showed that under intense UVA light benzene levels increased by as much as 53% in model solutions stored in non-UV stabilized bottles, whereas the use of UV stabilized polyethylene terephthalate bottles reduced benzene formation by about 13% relative to the non-UV stabilized bottles. Similar trends were observed for the 7 d study. Retail beverages and positive and negative controls were used to study the accelerated thermal testing conditions. The amount of benzene found in the positive controls and cranberry juice suggests that testing at 40 degrees C for 14 d may more reliably simulate end of shelf-life benzene formation in beverages. Except for cranberry juice, retail beverages were not found to contain detectable amounts of benzene (<0.05 ng/g) at the end of their shelf lives. PMID:20492277

Nyman, Patricia J; Wamer, Wayne G; Begley, Timothy H; Diachenko, Gregory W; Perfetti, Gracia A

2010-04-01

391

Investigation of the most effective provocation test for patients with coronary spastic angina: usefulness of accelerated exercise following hyperventilation.  

PubMed

This study sought to compare the clinical usefulness of the hyperventilation plus cold stress test or the hyperventilation combined with accelerated exercise test with other single tests in patients with coronary spastic angina. The study examined 24 patients (23 men, mean age 66 years) with angiographically confirmed coronary spastic angina and less than 50% stenosis. Moreover, none had spontaneous ST segment elevation before the study. Under no medication for at least 24 h prior, 4 procedures were performed from 09.00 h to 11.00 h: (i) a hyperventilation test for 5 min (HV(5)); (ii) HV(5) combined with a cold stress test for the last 2 min (HV(5)+CS(2)); (iii) a treadmill exercise test based on Bruce's protocol (TM(3)); and (iv) a treadmill exercise test accelerated at 1 min intervals according to Bruce's protocol immediately after HV(5) (HV(5)+TM(1)). The rate of appearance of chest pain and ischemia-induced ECG changes due to HV(5)+TM(1) were significantly higher than the other 3 tests. HV(5)+CS(2) was not superior to HV(5) alone. The incidence of provoked ST segment elevation due to HV(5)+TM(1) was higher than with the other 3 procedures. Thus, in patients with coronary spastic angina, no spontaneous ST segment elevation and near normal coronary arteries, HV(5)+CS(2) was no more useful than HV(5) alone. It is recommended that the newly designed HV(5)+TM(1) combination test be used for documenting evidence of ischemia in patients with coronary spastic angina, low disease activity and near normal coronary arteries. PMID:10084369

Sueda, S; Saeki, H; Otani, T; Ochi, N; Kukita, H; Kawada, H; Matsuda, S; Uraoka, T

1999-02-01

392

Surface pitting of heart valve disks tested in an accelerated fatigue tester.  

PubMed

There are various reports on the fracture of mechanical heart valves implanted in humans or animals and it has been pointed out that fractures are induced by erosion of the disk surface due to cavitation bubbles. Cavitation erosion on mechanical heart valves was studied using our originally designed accelerated fatigue tester. Several valve housings with different compliance values were used. The number and position of pits on the valve disk were measured using an optical microscope. Disk-closing velocity was measured and cavitation bubbles were monitored by a high-speed video camera. It was found that disk-closing velocity increased and cavitation erosion was enhanced with an increase in compliance of the valve holder. Therefore, careful attention should be paid to the compliance of an accelerated fatigue tester. PMID:11014678

Lee, H; Shimooka, T; Mitamura, Y; Yamamoto, K; Yuhta, T

2000-01-01

393

Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab  

SciTech Connect

A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type SRF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. The potential for radiation-induced degradation of the graphite is discussed.

Baffes, C.; Church, M.; Leibfritz, J.; Oplt, S.; Rakhno, I.; /Fermilab

2012-05-10

394

The High-Frequency\\/Acceleration Head Heave Test in Detecting Otolith Diseases  

Microsoft Academic Search

Objective: To investigate whether transient, high-acceleration interaural head heaves (translational vestibulo-ocular reflex (tVOR)) could aid in the diagnosis of otolith diseases. Study Design: Prospective cohort study. Setting: Tertiary referral center. Patients: Thirteen patients with symptoms suggestive of oto- lith diseases and 10 age-matched controls. Interventions: Patients underwent a clinical otoneurologic examination and standard laboratory audiovestibular evalua- tion, including audiometry, electronystagmography

Paul Kessler; David Tomlinson; Alan Blakeman; John Rutka; Paul Ranalli; Agnes Wong

2007-01-01

395

Experimental design and analysis for accelerated degradation tests with Li-ion cells.  

SciTech Connect

This document describes a general protocol (involving both experimental and data analytic aspects) that is designed to be a roadmap for rapidly obtaining a useful assessment of the average lifetime (at some specified use conditions) that might be expected from cells of a particular design. The proposed experimental protocol involves a series of accelerated degradation experiments. Through the acquisition of degradation data over time specified by the experimental protocol, an unambiguous assessment of the effects of accelerating factors (e.g., temperature and state of charge) on various measures of the health of a cell (e.g., power fade and capacity fade) will result. In order to assess cell lifetime, it is necessary to develop a model that accurately predicts degradation over a range of the experimental factors. In general, it is difficult to specify an appropriate model form without some preliminary analysis of the data. Nevertheless, assuming that the aging phenomenon relates to a chemical reaction with simple first-order rate kinetics, a data analysis protocol is also provided to construct a useful model that relates performance degradation to the levels of the accelerating factors. This model can then be used to make an accurate assessment of the average cell lifetime. The proposed experimental and data analysis protocols are illustrated with a case study involving the effects of accelerated aging on the power output from Gen-2 cells. For this case study, inadequacies of the simple first-order kinetics model were observed. However, a more complex model allowing for the effects of two concurrent mechanisms provided an accurate representation of the experimental data.

Doughty, Daniel Harvey; Thomas, Edward Victor; Jungst, Rudolph George; Roth, Emanuel Peter

2003-08-01

396

Surface roughness and color characteristics of wood treated with preservatives after accelerated weathering test  

Microsoft Academic Search

Wood samples treated with ammonium copper quat (ACQ 1900 and ACQ 2200), chromated copper arsenate (CCA), Tanalith E 3491 and Wolmanit CX-8 have been studied in accelerated weathering experiments. The weathering experiment was performed by cycles of 2h UV-light irradiation followed by water spray for 18min. The changes on the surface of the weathered samples were characterized by roughness and

Ali Temiz; Umit C. Yildiz; Ismail Aydin; Morten Eikenes; Gry Alfredsen; Grsel olakoglu

2005-01-01

397

Weatherability and combustibility of fire-retardant-impregnated wood after accelerated weathering tests  

Microsoft Academic Search

The weatherability and combustibility of fireretardant-impregnated wood during accelerated weathering for up to 2000 h were\\u000a evaluated. The ability of coating to retain fire-retardant chemicals against leaching was also examined using four coating\\u000a systems (water-borne or solvent-borne, pigmented or clear, film-forming or penetrating). Furthermore, the distribution of\\u000a fire retardants in the specimens was observed by scanning electron microscopy in combination

Toshiro Harada; Hiroshi Matsunaga; Yutaka Kataoka; Makoto Kiguchi; Junji Matsumura

2009-01-01

398

Characteristics of a 1200 V PT IGBT with trench gate and local life time control  

Microsoft Academic Search

A new 1200 V IGBT with a VCE(sat) of 1.9 V at 125C and 140 A\\/cm2 has been developed using a trench gate PT (punch-through) structure and local life time control. Compared to state-of-the-art third generation planar devices, this device represents a 30% improvement of on-state losses at almost twice the current density. This paper describes the structure and characteristics

Eric R. Motto; John F. Donlon; H. Takahashi; M. Tabata; H. Iwamoto

1998-01-01

399

A novel accelerated corrosion test for exhaust systems by means of power ultrasound  

Microsoft Academic Search

Cycling corrosion tests have been performed to simulate corrosion conditions in the cold end of an automotive exhaust system. A middle range 1.4512 (AISI 409) stainless steel is submitted to a conventional dip dry test (DDT) parallel to a similar test but including an additional external stress thanks to an ultrasonic transducer. This new ultrasonic test (so called UST) is

M. L. Doche; J. Y. Hihn; A. Mandroyan; C. Maurice; O. Hervieux; X. Roizard

2006-01-01

400

First Actual Field Test of Predicted Toppling Accelerations for Precarious Rocks Provided by the 1999 Hector Mine Earthquake  

NASA Astrophysics Data System (ADS)

An approximate field test of the precarious rock methodology has been provided by the Ms=7.1 Hector Mine earthquake of 16 October 1999 (Brune, 2001). The Hector Mine earthquake was a rare event on very low slip-rate faults near the eastern edge of the Eastern California Shear Zone. Preliminary trenching information indicates that the major fault segments that ruptured in this event had not ruptured in a similar event for more than 10 ka years (Lindvall et al., 2001; Rymer et al., 2001). Brune (1996) identified precarious rocks at Granite Pass, approximately 20 km northeast of the Bristol Fault, and classified them as ``precarious'', i.e., could be toppled by earthquake ground accelerations of less than 0.3~g, typically about 0.2~g (site number 3 in Brune, 1996). A photograph of three of the rocks was published: Figs. 2d and 2e of Brune (1996). The rock in Fig. 2e was apparently toppled by the Hector Mine earthquake (along with another nearby rock for which the photograph was not published). The quasi-static toppling acceleration estimated geometrically from photographs is about 0.2~g. The Amboy strong motion record from the Hector Mine earthquake, at approximately the same distance and the same general direction, recorded a peak ground acceleration of about 0.2g (Grazier et al., 2001, --actually 0.18~g measured from the seismogram available on the internet). The Intensity at Granite Pass is about I = V (Dewey, personal communication). Recent regressions of peak acceleration vs. Intensity, give an acceleration of somewhat less than 0.1~g, with considerable scatter. Both observations are consistent with the designation of the rocks as "precarious" by Brune (1996). We use the Amboy accelerogram , along with small Hector Mine aftershocks recorded at both the Amboy site and at Granite Pass sites, to make a rough correction for differences in path and site effects. The Granite Pass site (on solid granite) is richer in high frequencies than the Amboy site (underlain by layered volcanics and alluvium), but lower in peak velocity. The estimated acceleration at Granite Pass is about 0.12~g, as compared to the original Amboy accelerogram peak value of 0.18~g. Using two small earthquakes to estimate the transfer function does not take into account effects such as directivity, non-linearity and Moho reflection which might have been present in the main event. A more accurate estimate may be possible once we have recorded more aftershocks at both stations.

Anooshehpoor, R.; Brune, J. N.; Biasi, G. P.

2001-12-01

401

Optimization of parameters for the inline-injection system at Brookhaven Accelerator Test Facility  

SciTech Connect

We present some of our parameter optimization results utilizing code PARMLEA, for the ATF Inline-Injection System. The new solenoid-Gun-Solenoid -- Drift-Linac Scheme would improve the beam quality needed for FEL and other experiments at ATF as compared to the beam quality of the original design injection system. To optimize the gain in the beam quality we have considered various parameters including the accelerating field gradient on the photoathode, the Solenoid field strengths, separation between the gun and entrance to the linac as well as the (type size) initial charge distributions. The effect of the changes in the parameters on the beam emittance is also given.

Parsa, Z. [Brookhaven National Lab., Upton, NY (United States); Ko, S.K. [Ulsan Univ. (Korea, Republic of)

1995-10-01

402

Proposal of the Next Incarnation of Accelerator Test Facility at KEK for the International Linear Collider  

SciTech Connect

To reach design luminosity, the International Linear Collider (ILC) must be able to create and reliably maintain nanometer size beams. The ATF damping ring is the unique facility where ILC emittances are possible. In this paper we present and evaluate the proposal to create a final focus facility at the ATF which, using compact final focus optics and an ILC-like bunch train, would be capable of achieving 37 nm beam size. Such a facility would enable the development of beam diagnostics and tuning methods, as well as the training of young accelerator physicists.

Araki, S.; Hayano, H.; Higashi, Y.; Honda, Y.; Kanazawa, K.; Kubo, K.; Kume, T.; Kuriki, M.; Kuroda, S.; Masuzawa, M.; Naito, T.; Okugi, T.; Sugahara, R.; Takahashi, T.; Tauchi, T.; Terunuma, N.; Toge, N.; Urakawa, J.; Vogel, V.; Yamaoka, H.; Yokoya, K.; /KEK, Tsukuba /Beijing, Inst. High Energy Phys. /Novosibirsk, IYF /Daresbury /CERN /Hiroshima U. /Orsay, LAL /LLNL, Livermore /North Carolina A-T State U. /Oxford U. /Pohang Accelerator Lab. /Queen Mary, U. of London /Royal Holloway, U. of London /DESY /SLAC /University Coll. London /Oregon U. /Tokyo U.

2005-05-27

403

New method to test the gantry, collimator, and table rotation angles of a linear accelerator used in radiation therapy  

NASA Astrophysics Data System (ADS)

The precision of a medical LINear ACcelerator (LINAC) gantry rotation angle is crucial for the radiation therapy process, especially in stereotactic radio surgery, given the expected precision of the treatment and in Image Guided Radiation Therapy (IGRT) where the mechanical stability is disturbed due to the additional weight of the kV x-ray tube and detector. We present in this paper an extension of the Winston and Lutz test initially dedicated to control the size and the position of the isocenter of the LINAC and here adapted to test the gantry rotation angle with no additional portal images. This new method uses a test-object patented by QualiFormeD5 and is integrated in the QUALIMAGIQ software platform developed to automatically analyze images acquired for quality control of medical devices.

Beaumont, Stphane; Torfeh, Tarraf; Latreille, Romain; Ben Hdech, Yassine; Guedon, Jeanpierre

2011-03-01

404

The design and testing of a dual fiber textile matrix for accelerating surface hemostasis.  

PubMed

The standard treatment for severe traumatic injury is frequently compression and application of gauze dressing to the site of hemorrhage. However, while able to rapidly absorb pools of shed blood, gauze fails to provide strong surface (topical) hemostasis. The result can be excess hemorrhage-related morbidity and mortality. We hypothesized that cost-effective materials (based on widespread availability of bulk fibers for other commercial uses) could be designed based on fundamental hemostatic principles to partially emulate the wicking properties of gauze while concurrently stimulating superior hemostasis. A panel of readily available textile fibers was screened for the ability to activate platelets and the intrinsic coagulation cascade in vitro. Type E continuous filament glass and a specialty rayon fiber were identified from the material panel as accelerators of hemostatic reactions and were custom woven to produce a dual fiber textile bandage. The glass component strongly activated platelets while the specialty rayon agglutinated red blood cells. In comparison with gauze in vitro, the dual fiber textile significantly enhanced the rate of thrombin generation, clot generation as measured by thromboelastography, adhesive protein adsorption and cellular attachment and activation. These results indicate that hemostatic textiles can be designed that mimic gauze in form but surpass gauze in ability to accelerate hemostatic reactions. PMID:19489008

Fischer, Thomas H; Vournakis, John N; Manning, James E; McCurdy, Shane L; Rich, Preston B; Nichols, Timothy C; Scull, Christopher M; McCord, Marian G; Decorta, Joseph A; Johnson, Peter C; Smith, Carr J

2009-10-01

405

Boundary walking test: an accelerated scan method for greater system reliability  

Microsoft Academic Search

Printed circuit board (PCB) interconnect test and reliability is addressed. The boundary scan test methodology proposed in the IEEE standard 1149.1 is reviewed, and its limitation is critically analyzed. Based on this, a technique is proposed to automate the interconnect wiring test, which is performed as part of the power-on self-test. Essential to the idea is the use of a

John C. Chan; Reader Aids

1992-01-01

406

EFFECTS OF CARBONATION ON MECHANICAL PROPERTIES AND DURABILITY OF CONCRETE USING ACCELERATED TESTING METHOD  

Microsoft Academic Search

An experimental investigation was carried out to study the effect of carbonation on mechanical properties and durability of concrete. Ordinary portland concretes (OPC) with water\\/cement ratios of 0.58 and 0.48 and self-compacting concretes (SCC) with water\\/binder ratios of 0.40 and 0.36 were used in this study. Compressive strength test, splitting strength test, electrical resistivity test, rapid chloride penetration test (RCPT),

Jack M. Chi; Ran Huang; C. C. Yang

2002-01-01

407

Test particle acceleration in a numerical MHD experiment of an anemone jet  

NASA Astrophysics Data System (ADS)

Aims: To use a 3D numerical MHD experiment representing magnetic flux emerging into an open field region as a background field for tracing charged particles. The interaction between the two flux systems generates a localised current sheet where MHD reconnection takes place. We investigate how efficiently the reconnection region accelerates charged particles and what kind of energy distribution they acquire. Methods: The particle tracing is done numerically using the Guiding Center Approximation on individual data sets from the numerical MHD experiment. Results: We derive particle and implied photon distribution functions having power law forms, and look at the impact patterns of particles hitting the photosphere. We find that particles reach energies far in excess of those seen in observations of solar flares. However the structure of the impact region in the photosphere gives a good representation of the topological structure of the magnetic field. Three movies are only available in electronic form at http://www.aanda.org

Rosdahl, K. J.; Galsgaard, K.

2010-02-01

408

Facility for Advanced Accelerator Experimental Tests at SLAC (FACET) Conceptual Design Report  

SciTech Connect

This Conceptual Design Report (CDR) describes the design of FACET. It will be updated to stay current with the developing design of the facility. This CDR begins as the baseline conceptual design and will evolve into an 'as-built' manual for the completed facility. The Executive Summary, Chapter 1, gives an introduction to the FACET project and describes the salient features of its design. Chapter 2 gives an overview of FACET. It describes the general parameters of the machine and the basic approaches to implementation. The FACET project does not include the implementation of specific scientific experiments either for plasma wake-field acceleration for other applications. Nonetheless, enough work has been done to define potential experiments to assure that the facility can meet the requirements of the experimental community. Chapter 3, Scientific Case, describes the planned plasma wakefield and other experiments. Chapter 4, Technical Description of FACET, describes the parameters and design of all technical systems of FACET. FACET uses the first two thirds of the existing SLAC linac to accelerate the beam to about 20GeV, and compress it with the aid of two chicanes, located in Sector 10 and Sector 20. The Sector 20 area will include a focusing system, the generic experimental area and the beam dump. Chapter 5, Management of Scientific Program, describes the management of the scientific program at FACET. Chapter 6, Environment, Safety and Health and Quality Assurance, describes the existing programs at SLAC and their application to the FACET project. It includes a preliminary analysis of safety hazards and the planned mitigation. Chapter 7, Work Breakdown Structure, describes the structure used for developing the cost estimates, which will also be used to manage the project. The chapter defines the scope of work of each element down to level 3.

Amann, J.; Bane, K.; /SLAC

2009-10-30

409

A test of the nature of cosmic acceleration using galaxy redshift distortions.  

PubMed

Observations of distant supernovae indicate that the Universe is now in a phase of accelerated expansion the physical cause of which is a mystery. Formally, this requires the inclusion of a term acting as a negative pressure in the equations of cosmic expansion, accounting for about 75 per cent of the total energy density in the Universe. The simplest option for this 'dark energy' corresponds to a 'cosmological constant', perhaps related to the quantum vacuum energy. Physically viable alternatives invoke either the presence of a scalar field with an evolving equation of state, or extensions of general relativity involving higher-order curvature terms or extra dimensions. Although they produce similar expansion rates, different models predict measurable differences in the growth rate of large-scale structure with cosmic time. A fingerprint of this growth is provided by coherent galaxy motions, which introduce a radial anisotropy in the clustering pattern reconstructed by galaxy redshift surveys. Here we report a measurement of this effect at a redshift of 0.8. Using a new survey of more than 10,000 faint galaxies, we measure the anisotropy parameter beta = 0.70 +/- 0.26, which corresponds to a growth rate of structure at that time of f = 0.91 +/- 0.36. This is consistent with the standard cosmological-constant model with low matter density and flat geometry, although the error bars are still too large to distinguish among alternative origins for the accelerated expansion. The correct origin could be determined with a further factor-of-ten increase in the sampled volume at similar redshift. PMID:18235494

Guzzo, L; Pierleoni, M; Meneux, B; Branchini, E; Le Fvre, O; Marinoni, C; Garilli, B; Blaizot, J; De Lucia, G; Pollo, A; McCracken, H J; Bottini, D; Le Brun, V; Maccagni, D; Picat, J P; Scaramella, R; Scodeggio, M; Tresse, L; Vettolani, G; Zanichelli, A; Adami, C; Arnouts, S; Bardelli, S; Bolzonella, M; Bongiorno, A; Cappi, A; Charlot, S; Ciliegi, P; Contini, T; Cucciati, O; de la Torre, S; Dolag, K; Foucaud, S; Franzetti, P; Gavignaud, I; Ilbert, O; Iovino, A; Lamareille, F; Marano, B; Mazure, A; Memeo, P; Merighi, R; Moscardini, L; Paltani, S; Pell, R; Perez-Montero, E; Pozzetti, L; Radovich, M; Vergani, D; Zamorani, G; Zucca, E

2008-01-31

410

The advantages of having in the future a european accelerated weathering test for wood finishes  

Microsoft Academic Search

SummariesUsually, when a new product such as a paint or wood stain needs to be tested, the natural weathering method is used. This\\u000a kind of test is long and the results depend on the location of the test site. To obtain a faster assessment, the results of\\u000a which would be valid in any country, CTBA and several laboratories decided to

M. L. Roux; L. Podgorski

2000-01-01

411

Long life nickel electrodes for a nickel-hydrogen cell. III - Results of an accelerated test and failure analyses  

NASA Astrophysics Data System (ADS)

Nineteen different designs of nickel electrodes were tested in Ni/H2 boiler plate cells in an accelerated low earth orbit cycle regime to the end of their life. The failure analyses of these cells showed that the major performance changes due to the cycling was a severe reduction of their high rate discharge capability rather than an absolute capacity reduction. Many physical changes of the nickel electrodes were observed after the cycling test. These changes include dimensional expansion, sinter rupture, loose black powdering of the active material, morphology changes, active material migration, increase of pore volume, change of pore distribution, and increase of surface area. All of these were caused by active material expansion with cycling. Among these changes, the morphology change which involves migration of active material away from the current collecting nickel sinter appears to be that most responsible for the reduction of the rate capability.

Lim, H. S.; Verzwyvelt, S. A.

412

An investigation of the NOCSAE linear impactor test method based on in vivo measures of head impact acceleration in American football.  

PubMed

The performance characteristics of football helmets are currently evaluated by simulating head impacts in the laboratory using a linear drop test method. To encourage development of helmets designed to protect against concussion, the National Operating Committee for Standards in Athletic Equipment recently proposed a new headgear testing methodology with the goal of more closely simulating in vivo head impacts. This proposed test methodology involves an impactor striking a helmeted headform, which is attached to a nonrigid neck. The purpose of the present study was to compare headform accelerations recorded according to the current (n=30) and proposed (n=54) laboratory test methodologies to head accelerations recorded in the field during play. In-helmet systems of six single-axis accelerometers were worn by the Dartmouth College men's football team during the 2005 and 2006 seasons (n=20,733 impacts; 40 players). The impulse response characteristics of a subset of laboratory test impacts (n=27) were compared with the impulse response characteristics of a matched sample of in vivo head accelerations (n=24). Second- and third-order underdamped, conventional, continuous-time process models were developed for each impact. These models were used to characterize the linear head/headform accelerations for each impact based on frequency domain parameters. Headform linear accelerations generated according to the proposed test method were less similar to in vivo head accelerations than headform accelerations generated by the current linear drop test method. The nonrigid neck currently utilized was not developed to simulate sport-related direct head impacts and appears to be a source of the discrepancy between frequency characteristics of in vivo and laboratory head/headform accelerations. In vivo impacts occurred 37% more frequently on helmet regions, which are tested in the proposed standard than on helmet regions tested currently. This increase was largely due to the addition of the facemask test location. For the proposed standard, impactor velocities as high as 10.5 m/s were needed to simulate the highest energy impacts recorded in vivo. The knowledge gained from this study may provide the basis for improving sports headgear test apparatuses with regard to mimicking in vivo linear head accelerations. Specifically, increasing the stiffness of the neck is recommended. In addition, this study may provide a basis for selecting appropriate test impact energies for the standard performance specification to accompany the proposed standard linear impactor test method. PMID:20524744

Gwin, Joseph T; Chu, Jeffery J; Diamond, Solomon G; Halstead, P David; Crisco, Joseph J; Greenwald, Richard M

2010-01-01

413

Accelerated popcorn testing of high solder-reflow crack resistant molding compounds  

Microsoft Academic Search

In testing the resistance of a molding compound to popcorn failures after solder reflow, there are two basic options for shortening the moisture absorption phase: varying the severity of moisture exposure by varying the temperature and percent relative humidity or maintaining a constant humidity\\/temperature profile and varying the length of time the compounds are exposed. In addition, the total testing

T. R. Tubbs; A. A. Gallo

1998-01-01

414

Impact fuze testing at 3000 m/sec employing explosively accelerating plates  

SciTech Connect

The Explosives Testing Division at Sandia has developed a method of simulating a re-entry vehicle impacting the ground. The purpose of the simulation is to evaluate different fusing concepts. The design and operation of this impact testing facility are described.

Gill, W.

1981-01-01

415

Effects of zero mode and thin spectrum on the life time of atomic Bose Einstein condensates  

NASA Astrophysics Data System (ADS)

Reviewing the ideas developed in [1], the ground state life time of a finite size atomic Bose Einstein condensate is studied for coherent, squeezed coherent and thermal coherent ground states. Ground state evolution of coherent and squeezed coherent states in a double well potential is studied. Effects of thin spectrum on Bose-Einstein condensates is discussed and quasiparticle excitation lifetimes are calculated. It is shown that the effect of the states we use on the free energy vanishes in the thermodynamic limit. Possible extension to a double well potential and effect of a second broken symmetry is also discussed.

Birol, T.; Mstecapl?o?lu, .-. E.

2008-07-01

416

Reliability and Validity of a New Test of Change-of-Direction Speed for Field-Based Sports: the Change-of-Direction and Acceleration Test (CODAT)  

PubMed Central

Field sport coaches must use reliable and valid tests to assess change-of-direction speed in their athletes. Few tests feature linear sprinting with acute change- of-direction maneuvers. The Change-of-Direction and Acceleration Test (CODAT) was designed to assess field sport change-of-direction speed, and includes a linear 5-meter (m) sprint, 45 and 90 cuts, 3- m sprints to the left and right, and a linear 10-m sprint. This study analyzed the reliability and validity of this test, through comparisons to 20-m sprint (0-5, 0-10, 0-20 m intervals) and Illinois agility run (IAR) performance. Eighteen Australian footballers (age = 23.83 7.04 yrs; height = 1.79 0.06 m; mass = 85.36 13.21 kg) were recruited. Following familiarization, subjects completed the 20-m sprint, CODAT, and IAR in 2 sessions, 48 hours apart. Intra-class correlation coefficients (ICC) assessed relative reliability. Absolute reliability was analyzed through paired samples t-tests (p ? 0.05) determining between-session differences. Typical error (TE), coefficient of variation (CV), and differences between the TE and smallest worthwhile change (SWC), also assessed absolute reliability and test usefulness. For the validity analysis, Pearsons correlations (p ? 0.05) analyzed between-test relationships. Results showed no between-session differences for any test (p = 0.19-0.86). CODAT time averaged ~6 s, and the ICC and CV equaled 0.84 and 3.0%, respectively. The homogeneous sample of Australian footballers meant that the CODATs TE (0.19 s) exceeded the usual 0.2 x standard deviation (SD) SWC (0.10 s). However, the CODAT is capable of detecting moderate performance changes (SWC calculated as 0.5 x SD = 0.25 s). There was a near perfect correlation between the CODAT and IAR (r = 0.92), and very large correlations with the 20-m sprint (r = 0.75-0.76), suggesting that the CODAT was a valid change-of-direction speed test. Due to movement specificity, the CODAT has value for field sport assessment. Key points The change-of-direction and acceleration test (CODAT) was designed specifically for field sport athletes from specific speed research, and data derived from time-motion analyses of sports such as rugby union, soccer, and Australian football. The CODAT features a linear 5-meter (m) sprint, 45 and 90 cuts and 3-m sprints to the left and right, and a linear 10-m sprint. The CODAT was found to be a reliable change-of-direction speed assessment when considering intra-class correlations between two testing sessions, and the coefficient of variation between trials. A homogeneous sample of Australian footballers resulted in absolute reliability limitations when considering differences between the typical error and smallest worthwhile change. However, the CODAT will detect moderate (0.5 times the tests standard deviation) changes in performance. The CODAT correlated with the Illinois agility run, highlighting that it does assess change-of-direction speed. There were also significant relationships with short sprint performance (i.e. 0-5 m and 0-10 m), demonstrating that linear acceleration is assessed within the CODAT, without the extended duration and therefore metabolic limitations of the IAR. Indeed, the average duration of the test (~6 seconds) is field sport-specific. Therefore, the CODAT could be used as an assessment of change-of-direction speed in field sport athletes.

Lockie, Robert G.; Schultz, Adrian B.; Callaghan, Samuel J.; Jeffriess, Matthew D.; Berry, Simon P.

2013-01-01

417

How soccer players head the ball: A test of optic acceleration cancellation theory with virtual reality  

PubMed Central

We measured the movements of soccer players heading a football in a fully immersive virtual reality environment. In mid-flight the balls trajectory was altered from its normal quasi-parabolic path to a linear one, producing a jump in the rate of change of the angle of elevation of gaze (?) from player to ball. One reation time later the players adjusted their speed so that the rate of change of ? increased when it had been reduced and reduced it when it had been increased. Since the result of the players movement was to regain a value of the rate of change close to that before the disturbance, the data suggest that the players have an expectation of, and memory for, the pattern that the rate of change of ? will follow during the flight. The results support the general claim that players intercepting balls use servo control strategies and are consistent with the particular claim of Optic Acceleration Cancellation theory that the servo strategy is to allow ? to increase at a steadily decreasing rate.

McLeod, Peter; Reed, Nick; Gilson, Stuart; Glennerster, Andrew

2010-01-01

418

Accelerated Testing of HT-9 with Zirconia Coatings Containing Gallium using Raman Spectroscopy and XPS  

SciTech Connect

Laser Raman spectroscopy and x-ray photoelectron spectroscopy were used to study the evolution of composition of oxide films in the presence of zirconia coatings on miniature HT-9 alloy specimens subjected to elevated temperature in air. The experiments expanded on previous efforts to develop a quick-screening technique for candidate alloys for cladding materials (HT-9) and actinide-based mixed oxide fuel mixtures (represented by the zirconia coating) by investigating the effect of both coating composition and alloy pretreatment conditions on the high temperature reactions. In particular, the presence of the element Ga (a potential impurity in mixed oxide fuel) in the initial zirconia coating was found to accelerate the rate of oxide growth relative to that of yttria-stabilized zirconia studied previously. In addition, HT-9 samples that were subjected to different thermal pretreatments gave different results. The results suggest that the presence of Ga in a mixed oxide fuel will enhance the corrosion of HT-9 cladding under the conditions of this study, although the extent of enhancement is influenced by thermal pretreatment of the cladding material. The results also demonstrate the need to combine Raman spectroscopy with other techniques, particularly photoelectron spectroscopy, for optimizing composition and/or fabrication conditions of both cladding and oxide fuels for advanced nuclear reactors.

Windisch, Charles F.; Henager, Charles H.; Engelhard, Mark H.; Bennett, Wendy D.

2009-12-01

419

Lifetime Measurements of Carbon and Diamond Stripping Foils Tested in the Fermi National Accelerator Laboratory Linac  

Microsoft Academic Search

A foil testing apparatus was fabricated to test carbon versus diamond stripper foil life expectancy. The goal of this experiment is to find a target material more suitable for the proposed multi-mega-watt 8-GeV proton driver and booster system, which uses multiturn charge-exchange injection. Preparation includes tuning bending and quadrupole magnets and doing calculations of pertinent theoretical values, such as instantaneous

Trivia Penns Frazier

420

An accelerated stability test using the peroxide value as an index  

Microsoft Academic Search

SummaryA quick stability test for lard is described which depends on the peroxide content for identification of the rancid point.\\u000a By its use ordinary samples of lard can be evaluated for stability in a working day. Oleo oil also is being tested by this\\u000a method. It is applicable to edible fats and oils and hydrogenated shortenings. Typical peroxide curves for

A. E. King; H. L. Roschen; W. H. Irwin

1933-01-01

421

Accelerated weathering testing principles to estimate the service life of organic PV modules  

Microsoft Academic Search

Although polymer and organic photovoltaic modules represent a promising alternative to technologies based on inorganic semiconductors in terms of versatility and cost, reliable methods to test and improve their long-term stability in end-use environments still need to be developed. To be compatible with product development cycles and time-to-market constraints, the testing should provide data quickly enough to allow for changes

Olivier Haillant

2011-01-01

422

Collisionless Shocks in a Partially Ionized Medium. I. Neutral Return Flux and its Effects on Acceleration of Test Particles  

NASA Astrophysics Data System (ADS)

A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum between charged and neutral particles both upstream and downstream of the shock. In particular, neutrals that suffer a charge exchange downstream with shock-heated ions generate high-velocity neutrals that have a finite probability of returning upstream. These neutrals might then deposit heat in the upstream plasma through ionization and charge exchange, thereby reducing the fluid Mach number. A consequence of this phenomenon, which we refer to as the neutral return flux, is a reduction of the shock compression factor and the formation of a shock precursor upstream. The scale length of the precursor is determined by the ionization and charge-exchange interaction lengths of fast neutrals moving toward upstream infinity. In the case of a shock propagating in the interstellar medium, the effects of ion-neutral interactions are especially important for shock velocities <3000 km s-1. Such propagation velocities are common among shocks associated with supernova remnants, the primary candidate sources for the acceleration of Galactic cosmic rays. We then investigate the effects of the return flux of neutrals on the spectrum of test particles accelerated at the shock. We find that, for shocks slower than ~3000 km s-1, the particle energy spectrum steepens appreciably with respect to the naive expectation for a strong shock, namely, vpropE -2.

Blasi, P.; Morlino, G.; Bandiera, R.; Amato, E.; Caprioli, D.

2012-08-01

423

Assembly and Test of SQ01b, a Nb3Sn Quadrupole Magnet for the LHC Accelerator Research Program  

SciTech Connect

The US LHC Accelerator Research Program (LARP) consists of four US laboratories (BNL, FNAL, LBNL, and SLAC) collaborating with CERN to achieve a successful commissioning of the LHC and to develop the next generation of Interaction Region magnets. In 2004, a large aperture Nb{sub 3}Sn racetrack quadrupole magnet (SQ01) has been fabricated and tested at LBNL. The magnet utilized four subscale racetrack coils and was instrumented with strain gauges on the support structure and directly over the coil's turns. SQ01 exhibited training quenches in two of the four coils and reached a peak field in the conductor of 10.4 T at a current of 10.6 kA. After the test, the magnet was disassembled, inspected with pressure indicating films, and reassembled with minor modifications. A second test (SQ01b) was performed at FNAL and included training studies, strain gauge measurements and magnetic measurements. Magnet inspection, test results, and magnetic measurements are reported and discussed, and a comparison between strain gauge measurements and 3D finite element computations is presented

Ferracin, P.; Ambrosio, G.; Bartlett, S. E.; Bordini, B.; Carcagno, R.H.; Caspi, S.; Dietderich, D.R.; Feher, S.; Gourlay, S.A.; Hafalia, A.R.; Lamm, M.J.; Lietzke, A.F.; Mattafirri, S.; McInturff, A.D.; Orris, D.F.; Pischalnikov, Y.M.; Sabbi, G.L.; Sylvester, C.D.; Tartaglia, M.A.; Velev, G.V.; Zlobin, A.V.; Kashikhin, V.V.

2006-06-01

424

Phase-scan analysis results for the first drift tube linac module in the Ground Test Accelerator: data reproducibility and comparison to simulations  

Microsoft Academic Search

The Ground Test Accelerator (GTA) had the objective of producing a high-brightness, high-current H- beam. The major accelerator components were a 35 keV injector, a Radio Frequency Quadrupole, an intertank matching section, and a drift tube linac (DTL), consisting of 10 modules. This paper discusses the phase-scan technique which was used to experimentally determine the rf operating parameters for the

K. F. Johnson; O. R. Sander; G. O. Bolme; S. Bowling; R. Connolly; J. D. Gilpatrick; W. P. Lysenko; J. Power; E. A. Wadlinger; V. Yuan

1995-01-01

425

Phase-scan analysis results for the first drift tube linac module in the ground test accelerator: Data reproducibility and comparison to simulations  

SciTech Connect

The Ground Test Accelerator (GTA) had the objective of producing a high-brightness, high-current H- beam. The major accelerator components were a 35 keV injector, a Radio Frequency Quadrupole, an intertank matching section, and a drift tube linac (DTL), consisting of 10 modules. This paper discusses the phase-scan technique which was used to experimentally determine the rf operating parameters for the commissioning and routine operation of the first DTL module.

Johnson, K.F.; Sander, O.R.; Bolme, G.O. [and others

1995-05-01

426

Thermal Vacuum Accelerated Life Test on a Prototype Teldix Single-Gimballed Momentum Wheel.  

National Technical Information Service (NTIS)

A prototype TELDIX single-gimballed momentum wheel (SGMW) has been tested in vacuum at isothermal temperatures and with various thermal gradients. The mechanism consists of a momentum wheel which is oscillated in one plane through + or - 5 deg angular mot...

K. Parker J. C. Anderson

1979-01-01

427

Evaluation of accelerated weathering tests for three paint systems: a comparative study of their aging behaviour  

Microsoft Academic Search

The evolution of an epoxy-acrylurethane, alkyd and chlorinated rubber paints was studied under five standard artificial tests. The chemical evolution was followed through IR spectra; the variation in physical properties was studied from Vickers microhardness readings and gloss measurements. It was shown that the chemical evolution controls the loss of physical properties. However, the behaviour of the three paints towards

F. X Perrin; M Irigoyen; E Aragon; J. L Vernet

2001-01-01

428

Performance of zinc phosphate coatings obtained by cathodic electrochemical treatment in accelerated corrosion tests  

Microsoft Academic Search

The formation of zinc phosphate coating by cathodic electrochemical treatment and evaluation of its corrosion resistance is addressed. The corrosion behaviour of cathodically phosphated mild steel substrate in 3.5% sodium chloride solution exhibits the stability of these coatings, which lasts for a week's time with no red rust formation. Salt spray test convincingly proves the white rust formation in the

S. Jegannathan; T. S. N. Sankara Narayanan; K. Ravichandran; S. Rajeswari

2005-01-01

429

A new approach of accelerated life testing for metallic catalytic converters  

Microsoft Academic Search

The Environmental Protection Agency (EPA) and California Air Resources Board (CARB) requirements for high mileage durability of emission components make it necessary to ensure the mechanical robustness of metallic catalytic converters. In addition, the robustness of design features must be assessed in the early design development phase without resorting to vehicle fleet testing. By following established reliability methods, a new

Thomas Nagel; Jan Kramer; Manuel Presti; Axel Schatz; Juergen Breuer; Ron Salzman; John A. Scaparo; Andrew J. Montalbano

2004-01-01

430

Testing the Acceleration Hypothesis: Fluency Outcomes Utilizing Still-Versus Accelerated-Text in Sixth-Grade Students With Reading Disabilities  

Microsoft Academic Search

The acceleration hypothesis views reading rate simultaneously as both an independent and dependent variable that can be manipulated to encourage increases in reading indicators (Breznitz, 2006). Within this conceptualization, reading rate represents all the component sub-processes required for proficient reading and presents the opportunity for a potential training regimen where the student is prompted to maintain a faster than normal

David D. Paige

2011-01-01

431

Ethylene propylene cable degradation during LOCA research tests: tensile properties at the completion of accelerated aging  

SciTech Connect

Six ethylene-propylene rubber (EPR) insulation materials were aged at elevated temperature and radiation stress exposures common in cable LOCA qualification tests. Material samples were subjected to various simultaneous and sequential aging simulations in preparation for accident environmental exposures. Tensile properties subsequent to the aging exposure sequences are reported. The tensile properties of some, but not all, specimens were sensitive to the order of radiation and elevated temperature stress exposure. Other specimens showed more severe degradation when simultaneously exposed to radiation and elevated temperature as opposed to the sequential exposure to the same stresses. Results illustrate the difficulty in defining a single test procedure for nuclear safety-related qualification of EPR elastomers. A common worst-case sequential aging sequence could not be identified.

Bustard, L.D.

1982-05-01

432

An RF Waveguide Distribution System for the ILC Test Accelerator at Fermilab's NML  

SciTech Connect

An ILC R&D facility is being constructed in the NML building at Fermilab which, in addition to an injector and beam dump with spectrometer, will contain up to three cryomodules of ILC-type superconducting 9-cell cavities. This linac will be powered by a single klystron. As part of SLAC's contribution to this project, we will provide a distribution network in WR650 waveguide to the various cavity couplers. In addition to commercial waveguide components and circulators and loads, this system will include adjustable tap-offs, and customized hybrids. In one configuration, the circulators will be removed to test pair-wise cancellation of cavity reflections through hybrids. The system will be pressurized with nitrogen to 3 bar absolute to avoid the need for SF{sub 6}. The full distribution system for the first cryomodule will be delivered and installed later this year. We describe the design of the system and completed RF testing.

Nantista, Christopher; Adolphsen, Chris; Bowden, Gordon; Swent, Richard; McKee, Bobby; /SLAC

2007-06-27

433

Accelerated durability testing and evaluation of potential improvements of coatings for solar absorbers. Final report  

Microsoft Academic Search

About one-hundred commercially available solar absorptive coatings, both selective and non-selective, were tested for durability by simultaneously exposing them in a collector box with a cover plate to seventy-eight temperature cycles between 450+35°F (232+20°C) and 200+25°F and to solar radiation of about 22,000 langleys. Changes in the absorptance and emittance values were measured. Some of the coatings were also exposed

K. Raghunathan; C. C. Beatty; J. L. Cotsworth

1982-01-01

434

Accelerated-aging tests for predicting radiation degradation of organic materials  

Microsoft Academic Search

Long-term aging of organic materials in reactor containment buildings has become a major issue within the nuclear community. In this article, the status of radiation-aging qualification test requirements in several countries is reviewed, and problems with the current aging methodologies are described. These problems include dose-rate and synergistic effects and environmental synergisms, which have been found for many different polymeric

R. L. Clough; K. T. Gillen; J. L. Campan; G. Gaussens; H. Schoenbacher; T. Seguchi; H. Wilski; S. Machi

1984-01-01

435

Alkali mass balance during the accelerated concrete prism test for alkaliaggregate reactivity  

Microsoft Academic Search

The alkali mass balance was calculated in concrete specimens submitted to the storage conditions of the Canadian standard CSA A23.2-14A concrete prism test for expansion due to alkaliaggregate reaction (AAR). The alkali concentration of both the concrete pore solution expressed under high pressure and the water below specimens in storage pails (bottom water) was measured. Measurements were conducted over a

Patrice Rivard; Marc-Andr Brub; Jean-Pierre Ollivier; Grard Ballivy

2003-01-01

436

Accelerated post-glucose glycaemia and altered alliesthesia-test in Seasonal Affective Disorder  

Microsoft Academic Search

Background: Little is known about the link between mood, food and metabolic function in Seasonal Affective Disorder (SAD). Methods: We investigated this link in a combined glucose tolerancealliesthesia test in eight SAD patients in winter before and after one week light therapy, and in summer. Results: SAD patients exhibited faster post-glucose glycaemic and insulin responses (p<0.05), and increased hedonic ratings

Kurt Kruchi; Ulrich Keller; Georg Leonhardt; Daniel P. Brunner; Peter van der Velde; Hans-Joachim Haug; Anna Wirz-Justice

1999-01-01

437

Vacuum seals design and testing for a linear accelerator of the National Spallation Neutron Source  

SciTech Connect

Vacuum seals are very important to ensure that the Spallation Neutron Source (SNS) Linac has an optimum vacuum system. The vacuum joints between flanges must have reliable seals to minimize the leak rate and meet vacuum and electrical requirements. In addition, it is desirable to simplify the installation and thereby also simplify the maintenance required. This report summarizes an investigation of the metal vacuum seals that include the metal C-seal, Energized Spring seal, Helcoflex Copper Delta seal, Aluminum Delta seal, delta seal with limiting ring, and the prototype of the copper diamond seals. The report also contains the material certifications, design, finite element analysis, and testing for all of these seals. It is a valuable reference for any vacuum system design. To evaluate the suitability of several types of metal seals for use in the SNS Linac and to determine the torque applied on the bolts, a series of vacuum leak rate tests on the metal seals have been completed at Los Alamos Laboratory. A copper plated flange, using the same type of delta seal that was used for testing with the stainless steel flange, has also been studied and tested. A vacuum seal is desired that requires significantly less loading than a standard ConFlat flange with a copper gasket for the coupling cavity assembly. To save the intersegment space the authors use thinner flanges in the design. The leak rate of the thin ConFlat flange with a copper gasket is a baseline for the vacuum test on all seals and thin flanges. A finite element analysis of a long coupling cavity flange with a copper delta seal has been performed in order to confirm the design of the long coupling cavity flange and the welded area of a cavity body with the flange. This analysis is also necessary to predict a potential deformation of the cavity under the combined force of atmospheric pressure and the seating load of the seal. Modeling of this assembly has been achieved using both HKS/Abaqus and COSMOS/M, which are finite element packages for analysis of coupled, nonlinear problems. From these studies, the appropriate seals that are reliable for SNS long coupling cavities and beamline joints were determined.

Z. Chen; C. Gautier; F. Hemez; N. K. Bultman

2000-02-01

438

Evaluation of the reliability of commercial concentrator triple-junction solar cells by means of accelerated life tests (ALT)  

NASA Astrophysics Data System (ADS)

A temperature accelerated life test on commercial concentrator lattice-matched GaInP/GaInAs/Ge triple-junction solar cells has been carried out. The solar cells have been tested at three different temperatures: 119, 126 and 164 C and the nominal photo-current condition (820 X) has been emulated by injecting current in darkness. All the solar cells have presented catastrophic failures. The failure distributions at the three tested temperatures have been fitted to an Arrhenius-Weibull model. An Arrhenius activation energy of 1.58 eV was determined from the fit. The main reliability functions and parameters (reliability function, instantaneous failure rate, mean time to failure, warranty time) of these solar cells at the nominal working temperature (80 C) have been obtained. The warranty time obtained for a failure population of 5 % has been 69 years. Thus, a long-term warranty could be offered for these particular solar cells working at 820 X, 8 hours per day at 80 C.

Espinet-Gonzlez, Pilar; Algora, Carlos; Nez, Neftal; Orlando, Vincenzo; Vzquez, Manuel; Bautista, Jess; Araki, Kenji

2013-09-01

439

Search for major genes with progeny test data to accelerate the development of genetically superior loblolly pine  

SciTech Connect

This research project is to develop a novel approach that fully utilized the current breeding materials and genetic test information available from the NCSU-Industry Cooperative Tree Improvement Program to identify major genes that are segregating for growth and disease resistance in loblolly pine. If major genes can be identified in the existing breeding population, they can be utilized directly in the conventional loblolly pine breeding program. With the putative genotypes of parents identified, tree breeders can make effective decisions on management of breeding populations and operational deployment of genetically superior trees. Forest productivity will be significantly enhanced if genetically superior genotypes with major genes for economically important traits could be deployed in an operational plantation program. The overall objective of the project is to develop genetic model and analytical methods for major gene detection with progeny test data and accelerate the development of genetically superior loblolly pine. Specifically, there are three main tasks: (1) Develop genetic models for major gene detection and implement statistical methods and develop computer software for screening progeny test data; (2) Confirm major gene segregation with molecular markers; and (3) Develop strategies for using major genes for tree breeding.

NCSU

2003-12-30

440

Atmospheric life times and the ozone-depletion and global warming potentials of some halons  

SciTech Connect

The principal photochemical atmospheric characteristics of halons 1201 (CHF{sub 2}Br), 2401 (CHFBR-CF{sub 3}), 2301 (CH{sub 2}Br-CF{sub 3}), and 2311 (CHClBr-CF{sub 3}), including the rate constants of the reaction of the halons with hydroxyl radicals, the absorption cross section of solar UV radiation in the range of wavelengths of 190--300 nm, and the absorption cross sections of terrestrial IR radiation in the range of 450--1,500 cm{sup {minus}1}, were measured. By means of the obtained data the atmospheric life times, the ozone-depletion potentials, and the global-warming potentials of the compounds were determined using the methods developed in the Laboratory of the Chemistry of the Atmosphere, Institute of Energy Problems of Chemical Physics, Russian Academy of Sciences.

Gushchin, A.G.; Kasimovskaya, E.E.; Larin, I.K.; Orkin, V.L.; Khamaganov, V.G. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Energy Problems of Chemical Physics

1995-01-10

441

[ML(n)]2+ doubly charged systems: modeling, bonding, life times and unimolecular reactivity.  

PubMed

Doubly charged species in the gas phase have been an oddity for many years, but the possibility of generating and detecting them with the new available experimental techniques has faced the scientific community with challenging questions regarding their stability, bonding and reactivity. In this paper we analyze, mainly from a theoretical perspective, these questions for the particular subset of [ML(n)](2+) dications, where M is a metal and L an organic or inorganic ligand. Special attention is devoted to the challenges associated with their theoretical description, in particular as far as their bonding and their life times are concerned. A survey of their unimolecular reactivity is also presented as well as a discussion of the information available on dication affinities, and how they correlate with proton affinities or monocation affinities in general. PMID:21769338

Corral, Ins; Yez, Manuel

2011-07-18

442

A reconnaissance assessment of probabilistic earthquake accelerations at the Nevada Test Site  

SciTech Connect

We have made two interim assessments of the probabilistic ground-motion hazard for the potential nuclear-waste disposal facility at the Nevada Test Site (NTS). The first assessment used historical seismicity and generalized source zones and source faults in the immediate vicinity of the facility. This model produced relatively high probabilistic ground motions, comparable to the higher of two earlier estimates, which was obtained by averaging seismicity in a 400-km-radius circle around the site. The high ground-motion values appear to be caused in part by nuclear-explosion aftershocks remaining in the catalog even after the explosions themselves have been removed. The second assessment used particularized source zones and source faults in a region substantially larger than NTS to provide a broad context of probabilistic ground motion estimates at other locations of the study region. Source faults are mapped or inferred faults having lengths of 5 km or more. Source zones are defined by boundaries separating fault groups on the basis of direction and density. For this assessment, earthquake recurrence has been estimated primarily from historic seismicity prior to nuclear testing. Long-term recurrence for large-magnitude events is constrained by geological estimates of recurrence in a regime in which the large-magnitude earthquakes would occur with predominately normal mechanisms. 4 refs., 10 figs.

Perkins, D.M.; Thenhaus, P.C.; Hanson, S.L.; Algermissen, S.T.

1986-01-01

443

Accelerator-based tests of radiation shielding properties of materials used in human space infrastructures.  

PubMed

Shielding is the only practical countermeasure for the exposure to cosmic radiation during space travel. It is well known that light, hydrogenated materials, such as water and polyethylene, provide the best shielding against space radiation. Kevlar and Nextel are two materials of great interest for spacecraft shielding because of their known ability to protect human space infrastructures from meteoroids and debris. We measured the response to simulated heavy-ion cosmic radiation of these shielding materials and compared it to polyethylene, Lucite (PMMA), and aluminum. As proxy to galactic nuclei we used 1 GeV n iron or titanium ions. Both physics and biology tests were performed. The results show that Kevlar, which is rich in carbon atoms (about 50% in number), is an excellent space radiation shielding material. Physics tests show that its effectiveness is close (80-90%) to that of polyethylene, and biology data suggest that it can reduce the chromosomal damage more efficiently than PMMA. Nextel is less efficient as a radiation shield, and the expected reduction on dose is roughly half that provided by the same mass of polyethylene. Both Kevlar and Nextel are more effective than aluminum in the attenuation of heavy-ion dose. PMID:18301097

Lobascio, C; Briccarello, M; Destefanis, R; Faraud, M; Gialanella, G; Grossi, G; Guarnieri, V; Manti, L; Pugliese, M; Rusek, A; Scampoli, P; Durante, M

2008-03-01

444

The Next Linear Collider Test Accelerator's RF Pulse Compression And Transmission  

SciTech Connect

The overmoded rf transmission and pulsed power compression system for SLAC's Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II* pulse compressor has been developed and successfully tested at high power. The system produced a 200 MW, 250 ns wide pulse with a near-perfect flat-top. In this paper we describe the design and test results of the high power pulse compression system using SLED-II. The NLC rf systems use low loss highly over-moded circular waveguides operating in the TE01 mode. The efficiency of the systems is sensitive to the mode purity of the mode excited inside these guides. We used the so called flower petal mode transducer [2] to excite the TE01 mode. This type of mode transducer is efficient, compact and capable of handling high levels of power. To make more efficient systems, we modified this device by adding several mode selective chokes to act as mode purifiers. To manipulate the rf signals we used these modified mode converters to convert back and forth between over-moded circular waveguides and single-moded WR90 rectangular waveguides. Then, we used the relatively simple rectangular waveguide components to do the actual manipulation of rf signals. For example, two mode transducers and a mitered rectangular waveguide bend comprise a 90 degree bend. Also, a magic tee and four mode transducers would comprise a four-port-hybrid, etc. We will discuss the efficiency of an rf transport system based on the above methodology. We also used this methodology in building the SLEDII pulse compression system. At SLAC we built 4 of these pulse systems. In this paper we describe the SLEDII system and compare the performance of these 4 systems at SLAC. We report the experimental procedures used to measure their performance as well as the results of high power tests.

Tantawi, S.G.; Adelphson, C.; Holmes, S.; Lavine, Theodore L.; Loewen, R.J.; Nantista, C.; Pearson, C.; Pope, R.; Rifkin, J.; Ruth, R.D.; Vlieks, A.E.; /SLAC

2011-09-14

445

First Beam Waist Measurements in the Final Focus Beam Line at the KEK Accelerator Test Facility  

SciTech Connect

The ATF2 project is the final focus system prototype for the ILC and CLIC linear collider projects, with a purpose to reach a 37 nm vertical beam size at the interaction point using compact optics based on a novel scheme of local chromaticity correction. Construction of all components and installation were completed at the end of 2008. An initial commissioning phase followed in 2009, using larger than nominal {beta} functions at the interaction point, corresponding to reduced demagnification factors in comparison to the design, to limit effects from higher-order optical aberrations and hence simplify beam tuning procedures while key instrumentation was being tested and calibrated. In this paper, first measurements of dispersion and Twiss parameters are presented based on scanning the beam during this period with a set of tungsten wires located just behind the interaction point, using two complementary analysis methods.

Bai, Sha; /Beijing, Inst. High Energy Phys.; Aryshev, Alexander; /KEK, Tsukuba; Bambade, Philip; /KEK, Tsukuba /Orsay, IPN; McCormick, Doug; /SLAC; Bolzon, Benoit; /Annecy, LAPP; Gao, Jie; /Beijing, Inst. High Energy Phys.; Tauchi, Toshiaki; /KEK, Tsukuba; Zhou, Feng; /SLAC

2012-06-22

446

COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. I. NEUTRAL RETURN FLUX AND ITS EFFECTS ON ACCELERATION OF TEST PARTICLES  

SciTech Connect

A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum between charged and neutral particles both upstream and downstream of the shock. In particular, neutrals that suffer a charge exchange downstream with shock-heated ions generate high-velocity neutrals that have a finite probability of returning upstream. These neutrals might then deposit heat in the upstream plasma through ionization and charge exchange, thereby reducing the fluid Mach number. A consequence of this phenomenon, which we refer to as the neutral return flux, is a reduction of the shock compression factor and the formation of a shock precursor upstream. The scale length of the precursor is determined by the ionization and charge-exchange interaction lengths of fast neutrals moving toward upstream infinity. In the case of a shock propagating in the interstellar medium, the effects of ion-neutral interactions are especially important for shock velocities <3000 km s{sup -1}. Such propagation velocities are common among shocks associated with supernova remnants, the primary candidate sources for the acceleration of Galactic cosmic rays. We then investigate the effects of the return flux of neutrals on the spectrum of test particles accelerated at the shock. We find that, for shocks slower than {approx}3000 km s{sup -1}, the particle energy spectrum steepens appreciably with respect to the naive expectation for a strong shock, namely, {proportional_to}E{sup -2}.

Blasi, P.; Morlino, G.; Bandiera, R.; Amato, E. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, I-50125 Firenze (Italy); Caprioli, D. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08540 (United States)

2012-08-20

447

Accelerator Technology Division  

NASA Astrophysics Data System (ADS)

In fiscal year (FY) 1991, the Accelerator Technology (AT) division continued fulfilling its mission to pursue accelerator science and technology and to develop new accelerator concepts for application to research, defense, energy, industry, and other areas of national interest. This report discusses the following programs: The Ground Test Accelerator Program; APLE Free-Electron Laser Program; Accelerator Transmutation of Waste; JAERI, OMEGA Project, and Intense Neutron Source for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Super Collider; The High-Power Microwave Program; (Phi) Factory Collaboration; Neutral Particle Beam Power System Highlights; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

1992-04-01

448

Linear Accelerators  

SciTech Connect

In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

Sidorin, Anatoly [Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna (Russian Federation)

2010-01-05

449

Test of Spectrometers and Dosemeters for the Investigation of the Radiation Environment onboard Spacecraft and around High Energy Accelerators  

Microsoft Academic Search

Neutron fields encountered around high-energy accelerators and on board spacecraft are both characterised by a broad spectral distribution extending from thermal energies to several hundred MeV. Therefore they pose a considerable challenge for appropriate monitoring of this component for radiation protection purposes on ground and in orbit. This is of particular importance for new accelerators like the upcoming FAIR project

Gnther Reitz; Thomas Berger; Michelle Boudreau; Burkhard Wiegel; Marlies Luszik-Bhadra; Stefan Rttger; Ralf Nolte; Torsten Radon; Germany F. D. Smit

450

Absolute calibration of the antiproton detection efficiency for BESS below 1 GeV with an accelerator beam test at KEK-PS  

Microsoft Academic Search

An accelerator beam test was performed using a low-energy antiproton beam to measure the antiproton detection efficiency of the BESS detector. Measured and calculated efficiencies derived from the BESS Monte Carlo simulation based on GEANT\\/GHEISHA showed good agreement. With the detailed verification of the BESS simulation, results demonstrate that the relative systematic error in detection efficiency derived from the BESS

Y. Asaoka; K. Yoshimura; T. Yoshia; K. Abe; K. Anraku; M. Fujikawa; H. Fuke; S. Haino; K. Izumi; T. Maeno; Y. Makido; N. Matsui; H. Matsumoto; H. Matsunaga; M. Motoki; M. Nozaki; S. Orito; T. Sanuki; M. Sasaki; Y. Shikaze; T. Sonoda; J. Suzuki; K. Tanaka; Y. Toki; A. Yamamoto

2001-01-01

451

Multilayer insulation for the interconnect region in the Accelerator System String Test: A practical engineering approach for a new scheme of design and installation bridges  

Microsoft Academic Search

In order to minimize the heat leak in the Accelerator System String Test (ASST) inter-connect region, shield bridges and multilayer insulation (MLI) are provided. A sliding joint between shield bridges on adjacent magnets accommodates the contraction that occurs during cooldown. In the original design of the MLI bridges, thermal contraction was provided for by compressing the MLI. During assembly of

D. Baritchi; A. Jalloh

1993-01-01

452

Comprehensive beam jitter study for the commissioning of the intermediate matching section and drift tube linac at ground test accelerator  

SciTech Connect

An experiment on the Ground Test Accelerator (GTA) for the Neutral Particle Beam (NPB) at Los Alamos commissioned the intermediate matching section (IMS) and a single 3.2-MeV drift tube linac (DTL). A diagnostic platform or D-plate was used at the output of the DTL in order to measure various beam parameters. The D-plate and other diagnostic devices located in the IMS, provided measurement of the horizontal and vertical beam position, current, energy, and output phase. These instruments were installed to perform a complete beam jitter analysis based on the current beamline configuration to better understand the causes of any jitter sources as well as to prepare for the initial design of future feedback control systems. The study explored all types of jitter for various beamline configurations. Both interpulse jitter (jitter from pulse to pulse) and intrapulse jitter (jitter within each macropulse) were investigated. Spectral and statistical time analyses were used. Spectral analysis was employed to gain an understanding of the spectral contributions of various jitter sources to determine the degree of correction possible. Statistical time analysis gave a good overall representation of the jitter magnitude and allowed easy comparison of jitter for different beamline configurations, as well as an easy method for determining consistent problems.

Barr, D.S.; Gilpatrick, J.D.

1993-06-01

453

Application of a relational data base for documenting the Ground Test Accelerator cable routing and wiring interconnections  

SciTech Connect

The Ground Test Accelerator (GTA) has many different types of equipment and interconnections to support the operation. Various functions are performed by these equipments such as signal generation, instrument control, and diagnostics. All of the thousands of signals must be routed from the protected tunnel area into the operational control area of the building. Tabulating the routing of these cables, interconnections, terminations, and even the installation status, results in an enormous amount of data collection and maintenance. A relational data base program called Wireflex was written to allow real-time storage, instant recall, and reporting of this information. The operational environment is the VAX network with password security to protect the integrity of the stored data. The format of the program data bases, with the relatioships and interchange of information, will be described. Examples of input forms will show the type of information being stored and the indexing for searching specific entries. Reports will also be included displaying the flexibility of types as well as the ability to recover specific entries or ranges of information.

Blackwell, D.B.; Rogers, W.L.; Brown, V.W.; Ekeroth, G.A.; McGill, T.O.

1990-01-01

454

Comprehensive beam jitter study for the commissioning of the intermediate matching section and drift tube linac at ground test accelerator  

SciTech Connect

An experiment on the Ground Test Accelerator (GTA) for the Neutral Particle Beam (NPB) at Los Alamos commissioned the intermediate matching section (IMS) and a single 3.2-MeV drift tube linac (DTL). A diagnostic platform or D-plate was used at the output of the DTL in order to measure various beam parameters. The D-plate and other diagnostic devices located in the IMS, provided measurement of the horizontal and vertical beam position, current, energy, and output phase. These instruments were installed to perform a complete beam jitter analysis based on the current beamline configuration to better understand the causes of any jitter sources as well as to prepare for the initial design of future feedback control systems. The study explored all types of jitter for various beamline configurations. Both interpulse jitter (jitter from pulse to pulse) and intrapulse jitter (jitter within each macropulse) were investigated. Spectral and statistical time analyses were used. Spectral analysis was employed to gain an understanding of the spectral contributions of various jitter sources to determine the degree of correction possible. Statistical time analysis gave a good overall representation of the jitter magnitude and allowed easy comparison of jitter for different beamline configurations, as well as an easy method for determining consistent problems.

Barr, D.S.; Gilpatrick, J.D.

1993-01-01

455

Induction of apoptosis by accelerated heavy-ion beams in cultured fetal rat testes and its modification  

NASA Astrophysics Data System (ADS)

The increasing human activities in space missions make the study on effects from high-LET ionizing radiation an important issue to be addressed. We reported previously that prenatal irradiations with heavy-ion beams on gestation day 15 generally induced markedly detrimental effects on prenatal gonads, postnatal testicular development and male breeding activity in rats. To explore the mechanisms involved in radiation-induced gonocyte apoptosis in fetal gonads, which played a critical role in the fate of postnatal testis development, accelerated heavy-ion irradiations and organotypic culture of Wistar fetal rat testes were applied to investigations focused on cellular and molecular events after irradiations with or without chemical addition. Results showed that, in addition to the clustered distribution, both the time course and the percentage of apoptosis in gonocytes on gestation day 15 equivalent in vitro appeared similar to that in utero after exposure to either carbon-ion beams with a LET value of about 13 keV/m or neon-ion beams with a LET value of about 30 keV/m. Irradiations induced increased p53 expression in a dose dependent manner and decreased expressions of p21 and Bcl- 2 by Western Blot examination. Administration of pan-caspase inhibitor prior to irradiations effectively inhibited apoptosis occurrence and reduced the extent of clustered apoptosis, while such effects were not observed with the presence of p53 inhibitor, gap junction inhibitor, or nitric oxide specific scavenger. These findings indicated that irradiations of cultured fetal rat testes manifested pathologically similar apoptosis induction in gonocytes to that in utero. P53 expression was possibly responsible for the response to radiation damage rather than induction of apoptosis. The syncytial organization of gonocytes played a key role in formation of the clustered apoptosis, an event that both gap junction inhibitor and nitric oxide specific scavenger were incapable of preventing.

Wang, Bing; Tanaka, Kaoru; Shang, Yi; Fujita, Kazuko; Ninomiya, Yasuharu; Moreno, Stephanie G.; Coffigny, Herve; Hayata, Isamu; Murakami, Masahiro; Eguchi-Kasai, Kiyomi; Nenoi, Mitsuru

456

Equivalence of moisture and temperature in accelerated test method and its application in prediction of long-term properties of glass-fiber reinforced epoxy pipe specimen  

Microsoft Academic Search

Due to the difficulties in applying the timetemperature superposition principle to prediction of long-term properties of GRP pipe, the equivalence of moisture and temperature in an accelerated test method was established using short-term creep tests. The equivalence was proven both for elastic and creep compliance after the same physical aging time. Based on the equivalence, a moistureaging superposition principle was

J. Yao; G. Ziegmann

2006-01-01

457

Life time suicidal thoughts in an urban community in Hanoi, Vietnam  

PubMed Central

Background Suicidal thought is a risk factor and a stage in the suicidal process from planning to attempting and dying by suicide. To date, studies on suicidal thought in the general population, especially in Asian communities, have been limited. Method The WHO SUPRE-MISS (the multisite intervention study on suicidal behaviours) community survey questionnaire was filled in for 2,280 randomly selected residents of the DongDa district of Hanoi, Vietnam by means of face-to-face interviews. This multi-factor questionnaire includes such variables as sociodemographic information, suicidal thought and history of suicide attempts, physical health, alcohol consumption and medication. Results Prevalence rates for life time suicidal thoughts, suicide plans and suicide attempts were 8.9%, 1.1% and 0.4% respectively. Suicidal thoughts are associated with multiple characteristics, such as female gender, single/widowed/separated/divorced marital status, low income, lifestyle (use of alcohol, sedatives and pain relief medication), but not with low education or employment status. Having no religion and being a Buddhist appear to be protective factors for suicidal thought. The ratio of suicidal thoughts, suicide plans and suicide attempts on a lifetime basis is 22.3:2.8:1. Conclusion In Vietnam, as in Western and other Asian countries, suicidal thoughts are associated with similar negative psychosocial risk factors, lifestyle and emotional problems, which implies that suicide preventive measure developed elsewhere can be adjusted to Vietnamese condition. Understanding the unique and common risks in a culture may assist in prediction and control.

Thanh, Huong Tran Thi; Tran, Trung Nam; Jiang, Guo-Xin; Leenaars, Antoon; Wasserman, Danuta

2006-01-01

458

Survey of Hydrophone Acceleration Responses. Addendum.  

National Technical Information Service (NTIS)

A set of fourteen hydrophone types, some submitted for test by manufacturers and others the property of the Marine Physical Laboratory, were tested for acceleration response. The acceleration was introduced as vertical acceleration along the suspending ca...

E. D. Squier

1972-01-01

459

A Novel Angular Acceleration Sensor Based on the Electromagnetic Induction Principle and Investigation of Its Calibration Tests  

PubMed Central

An angular acceleration sensor can be used for the dynamic analysis of human and joint motions. In this paper, an angular acceleration sensor with novel structure based on the principle of electromagnetic induction is designed. The method involves the construction of a constant magnetic field by the excitation windings of sensor, and the cup-shaped rotor that cut the magnetic field. The output windings of the sensor generate an electromotive force, which is directly proportional to the angular acceleration through the electromagnetic coupling when the rotor has rotational angular acceleration. The mechanical structure and the magnetic working circuit of the sensor are described. The output properties and the mathematical model including the transfer function and state-space model of the sensor are established. The asymptotical stability of the sensor when it is working is verified by the Lyapunov Theorem. An angular acceleration calibration device based on the torsional pendulum principle is designed. The method involves the coaxial connection of the angular acceleration sensor, torsion pendulum and a high-precision angle sensor, and then an initial external force is applied to the torsion pendulum to produce a periodic damping angle oscillation. The angular acceleration sensor and the angle sensor will generate two corresponding electrical signals. The sensitivity coefficient of the angular acceleration sensor can be obtained after processing these two-channel signals. The experiment results show that the sensitivity coefficient of the sensor is about 17.29 mv/Krads2. Finally, the errors existing in the practical applications of the sensor are discussed and the corresponding improvement measures are proposed to provide effective technical support for the practical promotion of the novel sensor.

Zhao, Hao; Feng, Hao

2013-01-01

460

Dynamic mechanical and molecular weight measurements on polymer bonded explosives from thermally accelerated aging tests. I. Fluoropolymer binders  

SciTech Connect

The dynamic mechanical properties and molecular weight distribution of two polymer bonded explosives, LX-10-1 and PBX-9502, maintained at 23, 60, and 74/sup 0/C for 3 years were studied. LX-10-1 is 94.5% 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane explosive bonded together with 5.5% Viton A fluoropolymer. PBX-9502 is 95% triaminotrinitrobenzene explosive bonded with 5% Kel-F-800 fluoropolymer. There are two mechanical relaxations in the LX-10-1 in the military temperature range. The relaxation at -10/sup 0/C is associated with the glass transition temperature of the Viton A binder. A second weak relaxation occurs at about 30/sup 0/C in all LX-10-1 samples tested. This relaxation is probably associated with small amounts of crystallinity in the binder although this has not been demonstrated. There is a slight increase in modulus of the LX-10-1 with accelerated aging temperature. Changes in the dynamic mechanical properties of PBX-9502 are ascribed to crystallization of the chlorotrifluoroethylene component of the Kel-F-800 binder. The molecular weight of the Viton A binder decreased slight with increasing aging temperature. Using the kinetics of random scission the activation energy for polymer degradation in the presence of the explosive was 1.19 kcal/mole. The Arrhenius preexponential term and activation energy predict an expected use-life in excess of 60 years for LX-10-1. The Kel-F-800 in PBX-9502 is also extremely stable.

Hoffman, D.M.; Caley, L.E.

1981-01-01

461

Linear Accelerators  

SciTech Connect

In the linear accelerators the particles are accelerated by either electrostatic fields or oscillating radio frequency (RF) fields. Accordingly the linear accelerators are divided by three large groups: electrostatic, induction and RF accelerators. Overview of different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of the beam focusing in linacs are described.

Sidorin, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

2007-11-26

462

Failure criteria for long term Accelerated Power Cycling Test linked to electrical turn off SOA on IGBT module. A 4000 hours test on 1200A3300V module with AlSiC base plate  

Microsoft Academic Search

With AlSiC base plate technology for big module, the reliability about thermal cycling due to railway traction is largely improved and the accelerated Power Cycling Test time is increased a lot to reach over 6 months. Then it appears that these failure indicators as; Rth increasing, Vce increasing, or Iges increasing, must be linked to the interface behavior (thermal and

G. Coquery; R. Lallemand

2000-01-01

463

The Accelerated Weathering of a Radioactive Low-Activity Waste Glass Under Hydraulically Unsaturated Conditions: Experimental Results from a Pressurized Unsaturated Flow Test  

SciTech Connect

To predict the long-term fate of low- and high-level waste forms in the subsurface over geologic time scales, it is important to understand how the formation of an alteration phase or phases will affect radionuclide release from the corroding waste forms under repository-relevant conditions. To generate data to conduct performance assessment calculations for the low-activity waste (LAW) integrated disposal facility at the Hanford site in southeastern Washington state, accelerated weathering experiments are being conducted with the pressurized unsaturated flow (PUF) test method to evaluate the long-term release of radionuclides from immobilized low-activity waste (ILAW) glasses. The radionuclide release rate is a key parameter affecting the overall performance of the LAW disposal facility. Currently, there are three other accelerated weathering test methods being used to evaluate the long-term durability of glasses: product consistency test, vapor hydration test, and unsaturated drip test. In contrast to these test methods, PUF test mimic the near-field vadose zone environment, allow the corroding waste form to achieve its final reaction state, and accelerate the hydrolysis and aging processes by as much as 50 times over conventional static tests run at the same temperature. In this paper, we discuss the results of an accelerated weathering experiment conducted with the PUF apparatus to evaluate the corrosion rate of an ILAW glass, LAWAN102, made with actual Hanford waste taken from Tank 241-AN-102 (U). Results from this PUF test with LAWAN102 glass showed that after one and a half years of testing, the corrosion rate, based on B release, reached a steady-state release of 0.010 0.003 g m-2 d-1, which is approximately eight times lower than the HLP glass series previously tested. These results indicate that LAWAN102 glass performs well and is a durable ILAW glass. These results also highlight the importance of being able to predict, with some level of certainty, the alteration phase or phases that will form under repository-relevant conditions.

Pierce, Eric M.; McGrail, B. Peter; Valenta, Michelle M.; Strachan, Denis M.

2006-08-01

464

Degradation behaviors and failure analysis of NiBaTiO 3 base-metal electrode multilayer ceramic capacitors under highly accelerated life test  

Microsoft Academic Search

The degradation in insulation resistance under highly accelerated test conditions was investigated in terms of micro-structural and micro-chemical changes in dielectric layer of multilayer ceramic capacitor. The ceramic capacitors were prepared by using BaTiO3 powder with different size of 0.52?m, 0.55?m, and 0.58?m. As the particle size of BaTiO3 powder was increased, the capacitance and the dissipation factor were decreased.

Jungwoo Kim; Dongcheol Yoon; Minseok Jeon; Dowon Kang; Jeo