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ABSTRACT: The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight
9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic
control system, how to hold liquid level constant in the cryostat by regulation
of its Joule-Thompson JT-valve is very important after cryostat cool down to
2.0 K. The 72-cell cryostat liquid level response generally takes a long time
delay after regulating its JT-valve; therefore, typical PID control loop should
result in some cryostat parameter oscillations. This paper presents a type of
PID parameter self-optimal and Time-Delay control method used to reduce
cryogenic system parameters' oscillation.
09/2012;
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ABSTRACT: In this work, Escherichia coli MG1655 was engineered to produce ethanol and evolved in a laboratory process to obtain an acetate tolerant strain called MS04 (E. coli MG1655: ΔpflB, ΔadhE, ΔfrdA, ΔxylFGH, ΔldhA, PpflB::pdc ( Zm ) -adhB ( Zm ), evolved). The growth and ethanol production kinetics of strain MS04 were determined in mineral medium, mainly under non-aerated conditions, supplemented with glucose in the presence of different concentrations of sodium acetate at pH 7.0 and at different values of acid pH and a constant concentration of sodium acetate (2 g/l). Results revealed an increase in the specific growth rate, cell mass formation, and ethanol volumetric productivity at moderate concentrations of sodium acetate (2-10 g/l), in addition to a high tolerance to acetate because it was able to grow and produce a high yield of ethanol in the presence of up to 40 g/l of sodium acetate. Genomic analysis of the ΔpflB evolved strain identified that a chromosomal deletion of 27.3 kb generates the improved growth and acetate tolerance in MG1655 ΔpflB derivative strains. This deletion comprises genes related to the respiration of nitrate, repair of alkylated DNA and synthesis of the ompC gene coding for porin C, cytochromes C, thiamine, and colonic acid. Strain MS04 is advantageous for the production of ethanol from hemicellulosic hydrolysates that contain acetate.
Applied Microbiology and Biotechnology 06/2012; · 3.42 Impact Factor
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ABSTRACT: Novel thin-body architectures with complex geometry are becoming of large interest because they are expected to deliver the
ITRS prescribed on-current when semiconductor transistors are scaled into nanometer dimensions. We report on the development
of a 3D parallel Monte Carlo simulator coupled to a finite element solver for the Poisson equation in order to correctly describe
the complex domains of advanced FinFET transistors. We study issues such as charge assignment, field calculation, treatment
of contacts and parallelisation approach which have to be taken into account when using tetrahedral elements. The applicability
of the simulator is demonstrated by modelling a 10 nm gate length double gate MOSFET with a body thickness of 6.1 nm.
Journal of Computational Electronics 04/2012; 7(3):201-204. · 1.21 Impact Factor
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Y Escabi,
L San Miguel,
T. Judd,
J Hertza,
J Nicholson,
W Schiff,
C Bell,
B Estes,
C Millikin,
P Shelton, [......],
D Wygant,
P Klonoff,
D Carone,
T O'Connor Pennuto,
A Kluck,
J Ball,
L Shahani,
J Thomspon,
A Bowles,
M Greiffenstein
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ABSTRACT: The evaluation of bilingual children is a complicated endeavor because there are various views of how bilingualism affects brain organization and functioning. Added to that is the challenge of determining language development of Hispanic children living in a monolingual Spanish-speaking home in a Spanish-speaking country, but mostly exposed to English language television programming and, in some cases, English language school curriculum. Our case will review the evaluation process of a 14-year-old Puerto Rican boy with previous diagnoses of expressive language disorder and Attention-deficit/Hyperactivity Disorder (ADHD). The neuropsychological evaluation revealed an IQ within the average range, with significant differences between the perceptual reasoning, verbal comprehension, and processing speed. The case will summarize performance in verbal, executive, and psycho-educational measures with a thorough review of his developmental history and the interpretation of these neuropsychological achievement and behavioral measures in light of other variables influencing his difficulties.
Archives of Clinical Neuropsychology 09/2010; 25(6):475-583. · 2.18 Impact Factor
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ABSTRACT: This paper is about modeling and control of miniature quadrotors, with a special emphasis on attitude control. Mathematical models for simulation and nonlinear control approaches are introduced and subsequently applied to commercial aircraft: the DraganFlyer quadrotor, which has been hardware-modified in order to perform experimental autonomous flying. Hybrid Backstepping control and the Frenet-Serret theory is used for attitude stabilization, introducing a desired attitude angle acceleration function dependent on aircraft velocity. Finally, improvements on disturbance rejection and attitude tracking at moderate aircraft speeds are validated through various simulation scenarios (indoor navigation based on camera tracking), and flight experiments conducted on the DraganFlyer quadrotor.
Robotics and Automation (ICRA), 2010 IEEE International Conference on; 06/2010
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ABSTRACT: This paper is about modeling and control of Miniature Aerial Vehicles -MAVs for indoor scenarios, specially using, micro coaxial and quadrotor systems. Mathematical models for simulation and control are introduced and subsequently applied to the commercial aircraft: the DraganFlyer quadrotor and the Micro-Mosquito coaxial flying vehicle. The MAVs have been hardware-modified in order to perform experimental autonomous flight. A novel approach for control based on Hybrid Backstepping and the Frenet-Serret theory is used for attitude stabilization (Backstepping+FST), introducing a desired attitude angle acceleration function dependent on aircraft velocity. Results of autonomous hovering and tracking are presented based on the scheme we propose for control and attitude stabilization when MAV is maneuvering at moderate speeds.
Industrial Technology (ICIT), 2010 IEEE International Conference on; 04/2010
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ABSTRACT: In recent studies, Sample Entropy (SampEn) has demonstrated that can be a very promising non-linear index to assess atrial fibrillation (AF) organization from surface ECG recordings. However, non-linear regularity metrics are notably sensitive to noise. Thereby, in the present work, the effect that noise provokes in the SampEn-based organization estimation is analyzed. Given that AF organization was estimated by computing SampEn over the atrial activity (AA) signal, to evaluate the noise impact on AA regularity, 25 synthetic signals with different organization degrees were generated following a published model. Noise coming from real ECG recordings with different energy levels was added to the synthesized AA signals to obtain different signal to noise ratios (SNR). Results showed that SampEn, i.e., the AA irregularity, increased with noise, thus hiding the differences between organized and disorganized recordings. Precisely, in the presence of noise, SampEn values were increased, in average, by factors of 1.64, 4.46, 9.46 and 14.23 for SNRs of 24, 15, 9 and 3 dB, respectively. As a conclusion, a proper AF organization evaluation via SampEn requires noise reduction in the AA signal.
Computers in Cardiology, 2009; 10/2009
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ABSTRACT: Wavelet Sample Entropy (WSE) has been previously introduced as a successful methodology to predict electrical cardioversion (ECV) outcome of persistent atrial fibrillation (AF). The method estimates AF organization based on the combination of Wavelet decomposition and a nonlinear regularity metric, such as Sample Entropy (SampEn). However, WSE has been only computed by applying a specific wavelet function, such as the fourth-order biorthogonal wavelet. In the present work, with the objective of improving WSE robustness and its diagnostic ability in ECV outcome prediction, several orthogonal wavelet families were tested, and their performances were compared. Results indicated that, for all the functions of the same wavelet family, the same sensitivity and specificity values were obtained. Additionally, all the wavelet families reached the same diagnostic ability (80.95% sensitivity and 85.71% specificity), the same patients being incorrectly classified by all the families. These results suggest that any wavelet function could be indistinctly used to estimate successfully AF organization with the WSE methodology. As a consequence, the design of a customized wavelet function adapted to the specific characteristics of AA would not improve the WSE diagnostic ability in the prediction of ECV outcome in AF.
Computers in Cardiology, 2009; 10/2009
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ABSTRACT: In the present work, three methods based on the Sample Entropy (SampEn) non-invasive organization estimation of atrial fibrillation (AF) to predict its spontaneous termination are compared making use of the same patient's database. In the first strategy, the atrial activity (AA) is obtained through QRST cancellation. Next, the main atrial wave (MAW) of the AA is obtained by selective filtering centered on the dominant atrial frequency (DAF), thus yielding the time series for SampEn computation. In the second strategy, an equivalent wave to the MAW is obtained by applying seven levels of discrete wavelet decomposition to the AA. The sub-band containing the DAF is reconstructed back to time domain and evaluated with SampEn. In the last strategy, the time series is obtained as the concatenation of TQ segments, free of QRST complexes. The three methods were validated with a database containing a training set of 20 AF recordings, with known termination properties, and a test set of 30 recordings. For the learning set, sensitivity values were 100%, 80%, and 80% and specificity values were 90%, 90%, 100% for the methods based on selective filtering, wavelet transform and concatenation of TQ segments, respectively. Regarding the test signals, a sensitivity of 93.75% and a specificity of 85.71% were provided for the three methods. These coherent outcomes allowed us to conclude that the three techniques can estimate robustly AF organization and predict successfully paroxysmal AF termination.
Computers in Cardiology, 2009; 10/2009
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NEW BIOTECHNOLOGY; 09/2009
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ABSTRACT: In order to obtain a process time for canned low acid artichoke hearts, the heat resistance of Clostridium sporogenes PA 3679 in phosphate buffer (pH 7) and in artichoke puree (pH 5.2) was determined in the range of 100–118°C. DT values in artichoke puree were determined by the most probable number and plate count methods. D121°C values were deduced by extrapolation of the curves. An F 8.3/121 (see nomenclature section) target value of 1.8 min, equivalent to an F0= 2.5 min, was established considering a D121°C value of 0.36 min for artichoke puree. The cold point for canned artichoke hearts in 1/2 kg (71.5x117 mm) cans was determined, a set of heat penetration and cooling curves were obtained and the values of the parameters ‘j’ and ‘f’ were found. A process time was deduced, 21.5 and 23 min of heating at 121°C, following the methods of Patashnik (1954) and Hayakawa (1970, 1974) respectively, in order to reach the F0 target of 2.5 min for this new canned food. This process was adequate, as the inoculated experimental pack test showed no altered cans out of 50 inoculated after 21.5 min of heating at 121°C.
International Journal of Food Science & Technology 06/2007; 23(1):31 - 41. · 1.26 Impact Factor
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European journal of pain (London, England) 01/2006; 10(S1):S87c-S88. · 3.37 Impact Factor
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European journal of pain (London, England) 01/2006; 10(S1):S88b-S88. · 3.37 Impact Factor
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ABSTRACT: We used empirical mode decomposition (EMD) to assess the high frequency information of fetal HRV during different conditions of fetal activity. Beat-to-beat data of thirteen normal fetuses at term (36 to 40 gestation weeks) were obtained from abdominal ECG signals. In addition, corporal and breathing fetal movements were simultaneously observed using ultrasound B mode images. High frequency components of fetal HRV data were obtained by applying the EMD and by reconstructing the signals from components having frequencies higher than 0.3 Hz, according to the lowest frequency of fetal breathing movements observed in our data. Our results show significant differences in the power of high frequency components for episodes only with breathing movements vs no movements and vs. episodes having corporal movements (p<0.05). In conclusion, EMD seems to be a useful tool to analyze the effect of the FBM on non-stationary fetal HR time series
Computers in Cardiology, 2005; 10/2005
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ABSTRACT: The response of a susceptible coffee cultivar (Caturra) to infection by the root-knot nematode Meloidogyne exigua was compared histologically with that of cv. Iapar 59 possessing the recently identified Mex-1 resistance gene. The reproductive behaviour of the nematode was also compared in the two cultivars. Penetration and development in resistant plants were reduced in comparison with susceptible plants. Several cell features, including dark-stained cytoplasm and altered organelle structure, were observed in the resistant cultivar, indicating a hypersensitive-like (HR) response of the infested host cells. Features of giant cells were sometimes found beside necrotic-like areas, but the corresponding feeding sites were frequently associated with nematodes displaying abnormal shape. Six weeks after inoculation, root systems of cv. Caturra contained significantly more nematodes than those of cv. Iapar 59 (mean values 1574 and 41, respectively). The susceptible cultivar presented a minimum of 11 galls per plant, compared with only one or two galls per plant in the resistant cultivar. The findings are discussed in the context of plant–pathogen interactions.
Plant Pathology 07/2005; 54(4):476 - 482. · 2.13 Impact Factor
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ABSTRACT: A new MuCool test area (MTA) is under construction at Fermi National Accelerator Laboratory. This facility will house a cryo‐system composed of a liquid hydrogen absorber enclosed in a 5 Tesla magnet. The total volume of liquid hydrogen in the system is 25 liters. Helium gas at 14 K is provided by an in‐house refrigerator and will sub‐cool the hydrogen system to 17 K. Liquid hydrogen temperature in the absorber is chosen to satisfy the requirement of a density change smaller than +/− 2.5 %. To accommodate this goal and to remove the heat deposited by a beam, a pump will circulate liquid hydrogen at a rate of 450 g/s. The cooling loop was optimized with respect to the heat transport in liquid hydrogen and the pressure drop across the pump. Specific instrumentation will permit an intrinsically safe monitoring and control of the cryo‐system. Safety issues are the main driver of the cryo‐design.
AIP Conference Proceedings. 06/2004; 710(1):48-55.
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ABSTRACT: In the framework of the ITER (International Thermonuclear Experimental Reactor) project, the TFMC (Toroidal Field Model Coil) has been manufactured by European industry, using about 800 m of a 80 kA Nb<sub>3</sub>Sn cable-in-conduit conductor to wind the 98 turns of the coil. These turns are wound in 10 pancakes which are inserted inside machined stainless steel radial plates, and the whole winding pack is enclosed in a thick stainless steel casing. These passive conductive structures are expected to experience severe induced eddy currents and associated Joule heating during the last testing phase of the TFMC, when fast discharges are triggered to study the electromagnetic and thermal-hydraulic transient behavior of the coil. Diffusing through insulation, the Joule heating induced in the radial plates will add to the AC losses induced in the superconducting cable. The AC losses along the TFMC winding pack are deduced from accurate magnetic field computations performed by the 3-D magneto-static code TRAPS, the eddy currents are calculated with an analytical model using circuit equations, and the Joule heating diffusion is studied with a 1-D thermal analysis model. Using these heat loads as input data, the helium temperature and pressure increases in the conductor are computed with the finite element code GANDALF. The possibility of a quench of the whole magnet is discussed.
IEEE Transactions on Appiled Superconductivity 04/2002; · 1.04 Impact Factor
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ABSTRACT: During the TFMC (Toroidal Field Model Coil) quench experiment, a part of the pipe supplying helium to the TFMC is heated in order to reach, by forced circulation, the current sharing temperature of the conductor at peak field. During this experiment, the TFMC conductor is supplied with a current of 80 kA and the maximum magnetic field on the tested pancake is around 7.2 T. The aim of this paper is to determine the values of the experimental conditions needed to quench the TFMC conductor before the joint.
IEEE Transactions on Appiled Superconductivity 04/2002; · 1.04 Impact Factor
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ABSTRACT: Uniaxial tension tests of semihard copper sheets were studied by means of electronic spekle pattern interferometry (ESPI).
The setup allowed the authors to analyze in detail the transitions from elastic to plastic behavior and from homogeneous to
inhomogeneous plastic deformation. In agreement with the conventional definition of the yield point for copper fully plastic
behavior starded at permanent strains close to 0.005. The strain-hardening coefficient was very low at the early stage of
plastic flow (“easy glide”), increasing progressively until values on the order of 0.13 to 0.14 were reached at maximum load.
A this point, the appearance of unequally spaced fringes signaled the beginning of inhomogeneous deformation. With ESPI, this
occurrence may thus serve as a criterion to establish the forming limit of the material.
Experimental Mechanics 02/2001; 41(1):58-62. · 1.52 Impact Factor
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ABSTRACT: A correlation has been developed for the turbulent friction factor
f of a circular channel with a helical rib roughness of rectangular
cross section, which is relevant to the central channel (hole) in
two-channel cable-in-conduit conductors. The correlation is based on
data we measured on a pipe with three different types of helix. It
relates f with the Reynolds number Re and with suitable dimensionless
combinations of all relevant geometrical parameters of the problem,
i.e., hole diameter and helix gap and thickness. A limited comparison
with actual (QUELL) conductor data shows good agreement
IEEE Transactions on Appiled Superconductivity 04/2000; · 1.04 Impact Factor
